Technical Field
[0001] The present invention is directed to contact devices, and more particularly to a contact device suitable for a relay or electromagnetic switch for power loads.
Background Art
[0002] As shown in FIG. 25A, a prior contact device
1000 includes a sealed receptacle
1100 (see Japanese patent laid-open publication No.
10-326530). In the following explanation, an upper direction in FIG. 25A denotes a forward direction of the contact device
1000, and a lower direction in FIG. 25A denotes a rearward direction of the contact device
1000.
[0003] The sealed receptacle
1100 includes a contact case
1110 made of dielectric materials, a cylindrical member
1120 made of metals, and a closure plate
1130. The contact case
1110 is provided in its rear wall with an aperture
1111. The cylindrical member
1120 has its front end secured in an airtight manner to a periphery of the aperture
1111 of the contact case
1110. The closure plate
1130 is secured in an airtight manner to a rear end of the cylindrical member
1120. The sealed receptacle
1100 houses fixed contacts
1200 and a movable contact
1300.
[0004] The contact device
1000 further includes a drive device
1500 having a shaft
1400. The shaft
1400 has its front end attached to a holding case
1600. The holding case
1600 holds the movable contact
1300 movably along the forward/rearward direction. In addition, the holding case
1600 accommodates a contact pressure provision spring
1700. The contact pressure provision spring
1700 biases the movable contact
1300 forward such that the movable contact
1300 comes into contact with the fixed contacts
1200 at a desired contact pressure. The drive device
1500 moves forward/rearward the shaft
1400 by use of an electric magnet. The movable contact
1300 is kept away from the fixed contacts
1200 when the shaft
1400 is moved rearward by a predetermined distance. The movable contact
1300 comes into contact with the fixed contacts
1200 when the shaft
1400 is moved forward by a predetermined distance.
[0005] The sealed receptacle
1100 further houses an arc protection member
1140. As shown in FIG. 25B, the arc protection member
1140 includes a peripheral wall
1141 shaped into a cylindrical shape and a flange
1142. The peripheral wall
1141 is configured to conceal a junction between the contact case
1110 and the cylindrical member
1120 from the fixed contacts
1200 and the movable contact
1300. The arc protection member
1140 is pressed forward by pressing springs
11150 such that the flange
1142 comes into contact with the cylindrical member
1120. Thereby, the arc protection member
1140 is held in a predetermined position in the sealed receptacle
1100.
[0006] As apparent from the above, the prior contact device
1000 needs the pressing spring
1150 to hold the arc protection member
1140.
[0007] Furthermore,
WO 2007/060945 A1 discloses an electromagnetic switch comprising an electromagnet unit with a movable core and a contact unit having a fixed contact and a movable contact, similarly to a contact device as described in the introductory portion of claim 1.
Disclosure of Invention
[0008] In view of the above insufficiency, the present invention has been aimed to propose a contact device capable of reducing the number of parts necessitated for holding the arc protection member and reducing its production cost.
[0009] The contact device in accordance with the present invention is disclosed in claim 1.
[0010] In a preferred embodiment, the drive unit includes a shaft and an actuator. The shaft is disposed so as to penetrate through the movable contact, the bottom of the arc protection member, and the closure plate. The shaft is provided at its first end inside the sealed receptacle with a latch coming into contact with a fixed contact side surface of the movable contact. The shaft has its second end outside the sealed receptacle coupled to the actuator. The actuator is configured to move the shaft along its axial direction between a position where the latch separates the movable contact from the fixed contact and a position where the latch allows the movable contact to come into contact with the fixed contact. The sealed receptacle is configured to house a dust prevention member configured to cover a clearance between the shaft and a periphery of a through hole for the shaft formed in the bottom of the arc protection member. The dust prevention member includes a flange portion interposed between the contact pressure provision member and the bottom of the arc protection member.
[0011] In this preferred embodiment, it is possible to prevent dust from passing through the through hole of the arc protection member. Further, the dust prevention member is held by the contact pressure provision member. Therefore, it is unnecessary to add special parts for holding the dust prevention member. For example, the aforementioned dust is dissipation particles generated by contact of the movable contact with the fixed contact or by separation of the movable contact from the fixed contact.
[0012] In a preferred embodiment, any one of the closure plate and the bottom of the arc protection member includes a protrusion for positioning with the other including a recess for positioning configured to receive the positioning protrusion.
[0013] In this preferred embodiment, the arc protection member can be easily assembled into the contact device.
[0014] In a preferred embodiment, the drive unit includes a shaft, and an actuator including a fixed core penetrating through the closure plate, a movable core, and an electromagnet device. The shaft is disposed to penetrate through the movable contact, the bottom of the arc protection member, and the fixed core. The shaft is provided at its first end inside the sealed receptacle with a latch coming into contact with a fixed contact side surface of the movable contact. The shaft has its second end outside the sealed receptacle secured to the movable core. The electromagnet device is configured to generate a magnetic attraction between the fixed core and the movable core. The actuator is configured to control the electromagnet device to move the shaft along its axial direction between a position where the latch separates the movable contact from the fixed contact and a position where the latch allows the movable contact to come into contact with the fixed contact. The contact device includes a cap configured to fix the fixed core to the closure plate. The cap is secured to a surface of the closure plate opposed to the bottom of the arc protection member. Any one of the cap and the bottom of the arc protection member includes a protrusion for positioning with the other including a recess for positioning configured to receive the positioning protrusion.
[0015] In this preferred embodiment, the arc protection member can be easily assembled into the contact device.
[0016] In a more preferred embodiment, the contact device includes a plurality of the protrusions for positioning and a plurality of the recesses for positioning respectively corresponding to the plurality of the protrusions for positioning.
[0017] In this preferred embodiment, the arc protection member can be positioned while being prevented from rotating. Therefore, the arc protection member can be mounted yet without requiring adjusting a deviation caused by a rotation of the arc protection member. Thus, the contact device can be easily assembled. In addition, it is possible to reduce the production cost.
[0018] In a preferred embodiment, the drive unit includes a shaft, and an actuator including a fixed core penetrating through the closure plate, a movable core, and an electromagnet device. The shaft is disposed to penetrate through the movable contact, the bottom of the arc protection member, and the fixed core. The shaft is provided at its first end inside the sealed receptacle with a latch coming into contact with a fixed contact side surface of the movable contact. The shaft has its second end outside the sealed receptacle secured to the movable core. The electromagnet device is configured to generate a magnetic attraction between the fixed core and the movable core. The actuator is configured to control the electromagnet device to move the shaft along its axial direction between a position where the latch separates the movable contact from the fixed contact and a position where the latch allows the movable contact to come into contact with the fixed contact. The contact device includes a cap configured to fix the fixed core to the closure plate, the cap being secured to a surface of the closure plate opposed to the bottom of the arc protection member. The closure plate is provided with a first protrusion for positioning. The cap is provided with a second protrusion for positioning. The arc protection member is provided in its bottom with a first recess for positioning configured to receive the first protrusion and the second recess for positioning configured to receive a second protrusion.
[0019] In this situation, it is possible to position the arc protection member without rotating. Therefore, the arc protection member can be mounted yet without requiring adjusting a deviation caused by a rotation of the arc protection member. Thus, the contact device can be easily assembled. In addition, it is possible to reduce the production cost.
[0020] In a preferred embodiment, the bottom of the arc protection member has a positioning portion configured to surround the contact pressure provision member.
[0021] In this preferred embodiment, the contact pressure provision member can be easily attached to the arc protection member.
[0022] In a more preferred embodiment, the positioning portion has its inner surface inclined such that a distance between the inner surface and the contact pressure provision member increases as a distance from the bottom increases.
[0023] In this preferred embodiment, the inner surface of the positioning portion guides the contact pressure provision member to an inside of the positioning portion. Therefore, the contact pressure provision member can be more easily attached to the arc protection member.
[0024] In a preferred embodiment, the contact pressure provision member is a coil spring. The arc protection member is provided on its bottom with a positioning portion configured to intrude into the contact pressure provision member.
[0025] In this preferred embodiment, the contact pressure provision member can be easily attached to the arc protection member.
[0026] In a more preferred embodiment, the positioning portion has its outer surface inclined such that a distance between the outer surface and the contact pressure provision member increases as a distance from the bottom increases.
[0027] In this preferred embodiment, the outer surface of the positioning portion guides the contact pressure provision member to the inside of the positioning portion. Therefore, the contact pressure provision member can be more easily attached to the arc protection member.
Brief Description of Drawings
[0028]
FIG. 1 is a cross sectional view illustrating a primary part of a contact device of a first embodiment in accordance with the present invention,
FIG. 2A is an exploded perspective view illustrating the above contact device,
FIG. 2B is a perspective view illustrating a cover of the above contact device,
FIG. 3A is a cross sectional view illustrating an arc protection member of the above contact device,
FIG. 3B is a cross sectional view illustrating the arc protection member of the above contact device,
FIG. 4 is an explanatory view illustrating the arc protection member and a closure plate of the above contact device,
FIG. 5 is a perspective view illustrating a dust prevention member of the above contact device,
FIG. 6A is a cross sectional view illustrating a shock absorber of the above contact device,
FIG. 6B is a bottom view illustrating the shock absorber of the above contact device,
FIG. 7A is an explanatory view illustrating a method of attaching the shock absorber to a fixed core of the above contact device,
FIG. 7B is an explanatory view illustrating the method of attaching the shock absorber to the fixed core of the above contact device,
FIG. 8A is a cross sectional view illustrating a modification of the arc protection member of the contact device,
FIG. 8B is a cross sectional view illustrating the modification of the arc protection member of the contact device of FIG. 8A,
FIG. 9A is a front view illustrating an extinguishing unit of the above contact device,
FIG. 9B is a left side view illustrating the extinguishing unit of the above contact device,
FIG. 10A is a top view illustrating a base of the above contact device,
FIG. 10B is a cross sectional view of the base of the above contact device along the line A-A',
FIG. 11 is a right side view illustrating the base and a contacts mechanism unit of the above contact device,
FIG. 12 is an explanatory view illustrating a method of attaching the extinguishing unit to the base of the above contact device,
FIG. 13A is a right side view illustrating the above contact device without the cover,
FIG. 13B is a front view illustrating the above contact device without the cover,
FIG. 14A is a cross sectional view illustrating a primary part of a modification of the above contact device,
FIG. 14B is a cross sectional view illustrating the primary part of the modification of the above contact device of FIG. 14A,
FIG. 14C is a cross sectional view illustrating a primary part of a modification of the above contact device,
FIG. 14D is a cross sectional view illustrating the primary part of the modification of the above contact device of FIG. 14C,
FIG. 15A is an explanatory view illustrating a modification of the above contact device,
FIG. 15B is an explanatory view illustrating a modification of the above contact device,
FIG. 15C is an explanatory view illustrating a modification of the above contact device,
FIG. 16A is a rear view illustrating a modification of the shock absorber of the above contact device,
FIG. 16B is a perspective view illustrating the modification of the shock absorber of the above contact device of the FIG. 16A,
FIG. 16C is a rear view illustrating a modification of the shock absorber of the above contact device,
FIG. 16D is a perspective view illustrating the modification of the shock absorber of the above contact device of FIG. 16C,
FIG. 16E is a rear view illustrating a modification of the shock absorber of the above contact device,
FIG. 16F is a perspective view illustrating the modification of the shock absorber of the above contact device of FIG. 16E,
FIG. 17A is a cross sectional view illustrating a modification of the shock absorber of the above contact device,
FIG. 17B is a front view illustrating the modification of the shock absorber of the above contact device of FIG 17A,
FIG. 17C is a rear view illustrating the modification of the shock absorber of the above contact device of FIG. 17A,
FIG. 17D is a cross sectional view illustrating a situation where the modification of the shock absorber of the above contact device of FIG. 17A is attached to the fixed core,
FIG. 18A is a cross sectional view illustrating a modification of the shock absorber of the above contact device,
FIG. 18B is a front view illustrating the modification of the shock absorber of the above contact device of FIG. 18A,
FIG. 18C is a rear view illustrating the modification of the shock absorber of the above contact device of FIG. 18A,
FIG. 19A is a cross sectional view illustrating a modification of the shock absorber of the above contact device,
FIG. 19B is a front view illustrating the modification of the shock absorber of the above contact device of FIG. 19A,
FIG. 19C is a rear view illustrating the modification of the shock absorber of the above contact device of FIG. 19A,
FIG. 19D is a cross sectional view illustrating a situation where the modification of the shock absorber of the above contact device of FIG. 19A is attached to the fixed core,
FIG. 20A is a schematic view illustrating a modification of the above contact device,
FIG. 20B is an enlarged view illustrating the modification of the above contact device of FIG. 20A,
FIG. 21A is an explanatory view illustrating a method of attaching an external connection terminal to a fixed terminal of the modification of the above contact device of FIG. 20A,
FIG. 21B is an explanatory view illustrating the method of attaching the external connection terminal to the fixed terminal of the modification of the above contact device of FIG. 20A,
FIG. 22A is an explanatory view illustrating a method of attaching the external connection terminal to the fixed terminal of a modification the above contact device,
FIG. 22B is an explanatory view illustrating the method of attaching the external connection terminal to the fixed terminal of the modification the above contact device of FIG. 22A,
FIG. 22C is an explanatory view illustrating the method of attaching the external connection terminal to the fixed terminal of the modification the above contact device of FIG. 22A,
FIG. 22D is a perspective view illustrating a modification of the external connection terminal of the above contact device,
FIG. 23A is a partial plan view illustrating a modification of the external connection terminal of the above contact device,
FIG. 23B is a partial plan view illustrating a modification of the external connection terminal of the above contact device,
FIG. 23C is a partial plan view illustrating a modification of the external connection terminal of the above contact device,
FIG. 23D is a partial plan view illustrating a modification of the external connection terminal of the above contact device,
FIG. 24A is an explanatory view illustrating a method of attaching the external connection terminal to the fixed terminal of a modification the above contact device,
FIG. 24B is an explanatory view illustrating the method of attaching the external connection terminal to the fixed terminal of the modification the above contact device of FIG. 24A,
FIG. 24C is a perspective view illustrating the modification of the external connection terminal of the above contact device of FIG. 22D,
FIG. 25A is a cross sectional view illustrating a prior contact device, and
[0029] FIG. 25B is a perspective view illustrating an arc protection member and pressing springs of the prior contact device.
Best Mode for Carrying Out the Invention
[0030] The contact device
10 of an embodiment in accordance with the present invention is so-called a sealed contact device (or so-called a silent contact device). As shown in FIGS. 2A and 2B, the contact device
10 includes a contacts mechanism unit
11, an extinguishing unit
12, and a housing
13 configured to house the contacts mechanism unit
11 and the extinguishing unit
12. In a following explanation, an upward direction in FIG. 1 denotes a forward direction of the contact device
10, and a downward direction in FIG. 1 denotes a rearward direction of the contact device
10, and a left direction in FIG. 1 denotes a left direction of the contact device
10, and a right direction in FIG. 1 denotes a right direction of the contact device
10. In addition, an upward direction in FIG. 2A denotes an upward direction of the contact device
10, and a downward direction in FIG. 2A denotes a downward direction of the contact device
10.
[0031] As shown in FIG. 1, the contacts mechanism unit
11 includes a sealed receptacle
20 configured to house a fixed contact
31, a movable contact
40, and an arc protection member
60, and a drive unit
50.
[0032] The drive unit
50 is configured to move the movable contact
40 between an on-position and an off-position. The on-position is defined as a position where the movable contact
40 is kept in contact with the fixed contact
31. The off-position is defined as a position where the movable contact
40 is kept away from the fixed contact
31. The aforementioned drive unit
50 includes a contact pressure provision spring (contact pressure provision member)
51, a fixed core
52, a shaft
53, a movable core
54, a return spring
55, and an electromagnet device
56. In this drive unit
50, the fixed core
52, the movable core
54, and the electromagnet device
56 constitute an actuator configured to move the shaft
53 along its axial direction.
[0033] The sealed receptacle
20 includes a case (contact case)
21 made of dielectric materials, a cylindrical member
22 made of metals, and a closure plate
23.
[0034] The case
21 is provided with an aperture
211 in its rear wall (first wall). The case
21 is provided with two through holes
212 for fixed terminals
30 in a right portion and left portion of its front wall (second wall opposed to the first wall). The dielectric material of the case
21 is preferred to be a ceramic having heat resistance.
[0035] The cylindrical member
22 is defmed as a junction member for connecting the closure plate
23 to the case
21. The cylindrical member
22 is shaped into a cylindrical shape. An axial center portion of the cylindrical member
22 is wholly bent to narrow its front aperture relative to its rear aperture.
[0036] The closure plate
23 is made of magnetic metals (e.g. irons) and is shaped to have a rectangular shape. The closure plate
23 has enough dimensions to cover the rear aperture of the cylindrical member
22. The closure plate
23 is provided with a recess
231 in a center of its front surface. A through hole
232 for the fixed core
52 is formed in a center of a bottom of the recess
231. Further, a cap
24 and a core case
25 are fixed to the closure plate
23.
[0037] In respect to the sealed receptacle
20, the cylindrical member
22 has its front end (first axial end) secured in an airtight manner to a periphery of the aperture
211 of the rear wall of the case
21. The cylindrical member
22 further has its rear end (second axial end) secured in an airtight manner to the closure plate
23. An extinguishing gas (e.g. hydrogen gas) is sealed in the sealed receptacle
20.
[0038] The fixed terminals
30 are secured to the front wall of the sealed receptacle
20. The fixed terminal
30 is made of metals (e.g. a copper material) and is shaped into a circular cylindrical shape. The fixed contact
31 is secured to a rear end (first end) of the fixed terminal
30. The fixed contact
31 is attached to the front wall of the sealed receptacle
20 through the fixed terminal
30. The fixed terminal
30 is provided with a flange
32 at its front end (second end) and is provided with a screw hole
33 in its front end. In the present embodiment, the fixed terminal
30 and the fixed contact
31 are provided as separate parts. However, a part of the fixed terminal
30 may be defined as the fixed contact
31.
[0039] The front end of the fixed terminal
30 extends out through the through hole
212 from the sealed receptacle
20. In other words, the fixed terminal
30 is attached to the sealed receptacle
20 to place its rear end inside the sealed receptacle
20 and to place its front end outside the sealed receptacle
20. In this situation, the flange
32 of the fixed terminal
30 is fixed in an airtight manner to the front wall of the case
21, by use of a brazing method or the like. The screw hole
33 of the fixed terminal
30 is used for fixing an external connection terminal
34 (see FIG. 2) to the fixed terminal
30 by use of a screw. The external connection terminal
34 is used for connection of the fixed contact
31 and an external circuit (e.g. an electrical circuit of a mounted board on which the contact device
10 is mounted).
[0040] The movable contact
40 is made of metals (e.g. a copper material) and is shaped into a rectangular plate shape. The movable contact
40 has enough dimensions to come into contact with both the right and left fixed contacts
31. In the present embodiment, right and left portions of the movable contact
40 are respectively defined as a contact portion
41 for the fixed contact
31. The movable contact
40 further has a through hole
42 for a shaft. The through hole
42 penetrates through a center of the movable contact
40 along a thickness direction of the movable contact
40. In the present embodiment, a part of the movable contact
40 is used as the contact portion
41. However, the contact portion
41 may be provided as a separate part from the movable contact
40.
[0041] As shown in FIGS. 3A and 3B, the arc protection member
60 includes a cylindrical peripheral wall
61 and a bottom
62. The peripheral wall
61 is configured to conceal a junction between the case
21 and the cylindrical member
22 from the fixed contacts
31 and the movable contact
40. The bottom
62 is configured to cover a rear aperture of the peripheral wall
61. The bottom
62 is interposed between the movable contact 40 and the closure plate
23. The bottom
62 is provided in its center with a through hole
63 for a shaft
53.
[0042] The contact pressure provision spring (hereinafter abbreviated as "spring")
51 is a coil spring. The spring
51 is interposed between the bottom
62 of the arc protection member
60 and the movable contact
40. The spring
51 has its natural length to be always compressed irrespective of a position of the movable contact
40. That is, the spring
51 is interposed between the movable contact
40 and the bottom
62 of the arc protection member
60 so as to come into resilient contact with both the movable contact
40 and the bottom
62 of the arc protection member
60 irrespective of a position of the movable contact
40. The spring
51 is not limited to a coil spring and may be a plate spring. An elastic member (e.g. a rubber) can be adopted as the contact pressure provision member instead of the spring
51.
[0043] By the way, as shown in FIG. 4, the bottom
62 is provided with a recess
64 for positioning in its rear surface (surface of the bottom
62 opposed to the closure plate
23). The recess
64 is formed in the rear surface of the bottom
62 so as to receive a nipper portion
241 of an after-mentioned cap
24 when the arc protection member
60 is placed in a predetermined position relative to the closure plate
23.
[0044] Meanwhile, the bottom
62 is provided in its front surface (surface of the bottom
62 opposed to the movable contact
40) with a positioning portion
65 for the spring
51. The positioning portion
65 is shaped into a circular cylindrical shape to surround a rear end (end of the spring
51 which comes into contact with the bottom
62) of the spring
51. The positioning portion
65 further has its inner surface inclined such that a distance between the inner surface and the spring
51 increases as a distance from the bottom
62 increases (the distance between the inner surface and the spring
51 is made greater towards a front end of the positioning portion
65 than at a rear end of the positioning portion
65). In other words, the positioning portion
65 has a tapered shape to guide the rear end of the spring
51 to an inside of the positioning portion
65. The positioning portion
65 is not always required to have a cylindrical shape. The positioning portion
65 may be defined by a plurality of protrusions arranged to surround the rear end of the spring
51.
[0045] A dust prevention member
26 is located inside the positioning portion
65. The dust prevention member
26 is configured to cover a clearance between the shaft
53 and a periphery of the through hole
63 of the arc protection member
60. The dust prevention member
26 is made of an elastic material (e.g. an elastomer such as a silicone rubber). As shown in FIG. 5, the dust prevention member
26 has a cylindrical portion
261 shaped into a circular cylindrical shape. The cylindrical portion
261 has its inner diameter greater than an inner diameter of the through hole
63. The dust prevention member
26 has a front wall portion
262 covering a front aperture of the cylindrical portion
261. The front wall portion
262 is provided in its center with a hole
263. The hole
263 has its inner diameter slightly smaller than an outer diameter of the shaft
53. Consequently, an inner periphery of the hole
263 comes into close contact with an outer periphery of the shaft
53. The front wall portion
262 is formed to have its peripheral portion of the hole
263 thicker than its outer edge portion. Accordingly, it is possible to improve contact of the inner periphery of the hole
263 and the outer periphery of the shaft
53. The dust prevention member
26 further has a flange portion
264. The flange portion
264 extends out from the rear end of the cylindrical portion
261. As shown in FIG. 3B, the flange portion
264 is interposed between the rear end of the spring
51 and the bottom
62. That is, the flange portion
264 of the dust prevention member
26 is held by the spring
51 and the bottom
62 between the spring
51 and the bottom
62. Thereby, the dust prevention member
26 is fixed to the arc protection member
60.
[0046] The fixed core
52 is made of a magnetic material and is shaped into a cylindrical shape (e.g. a circular cylindrical shape). The fixed core
52 is provided at its front end with a flange
521 configured to be hooked over a periphery of the through hole
232 of the closure plate
23.
[0047] The aforementioned cap
24 is used for fixing the fixed core
52 to the closure plate
23. The cap
24 includes the nipper portion
241 being in the form of a rectangular plate shape and configured to hold the flange
521 of the fixed core
52 in association with the closure plate
23. The nipper portion
241 is defined as a protrusion for positioning corresponding to the recess
64 of the arc protection member
60. Fixing portions
242 are provided to right and left ends of a rear surface of the nipper portion
241, respectively. The cap
24 is fixed to the closure plate
23 by bonding rear surfaces of the fixing portions
242 to the front surface of the closure plate
23. The nipper portion
241 is further provided with a through hole
243 for the shaft
53. The through hole
243 has its inner diameter smaller than an inner diameter of the fixed core
52.
[0048] The front end of the fixed core
52 is covered with a shock absorber
58. The shock absorber
58 is made of an elastic material (e.g. an elastomer such as a silicone rubber). As shown in FIGS. 6A and 6B, the shock absorber
58 includes a first resilient portion
581 and a second resilient portion
582. The first resilient portion
581 is interposed between the flange
521 of the fixed core
52 and the nipper portion
241 of the cap
24. The second resilient portion
582 is interposed between the flange
521 of the fixed core
52 and the closure plate
23. Both the first resilient portion
581 and the second resilient portion
582 are in the form of a circular disk shape. The first resilient portion
581 is provided in its center with a through hole
583 for the shaft
53. The second resilient portion
582 is provided in its center with a through hole
584 for the fixed core
52.
[0049] Additionally, the shock absorber
58 includes a connection portion
585 configured to integrally connect an outer edge of the first resilient portion
581 to an outer edge of the second resilient portion
582. It is noted that a distance between a rear surface of the first resilient portion
581 and a front surface of the second resilient portion
582 is identical to a thickness of the flange
521 of the fixed core
52.
[0050] The shock absorber
58 is attached to the fixed core
52 as follows. As shown in FIGS. 7A and 7B, the flange
521 of the fixed core
52 is inserted into the shock absorber
58 via the through hole
584. In order to attach the shock absorber
58 to the fixed core
52, the second resilient portion
582 is elastically deformed such that the inner diameter of the through hole
584 becomes greater than the outer diameter of the flange
521.
[0051] In the prior contact device, the shock absorber
58 includes the first resilient portion
581 and the second resilient portion
582. However, in the prior contact device, the first resilient portion
581 is separated from the second resilient portion
582. Therefore, in order to attach the shock absorber
58 to the fixed core
52, it is necessary to attach the first resilient portion
581 to the front surface side of the flange
521 and also to attach the second resilient portion
582 to the rear surface side of the flange
522. Additionally, it is difficult to manipulate the first resilient portion
581 and the second resilient portion
582 individually. Therefore, the shock absorber
58 can not be easily attached to the fixed core
52.
[0052] However, in the contact device
10 of the present embodiment, the shock absorber
58 includes the connection portion
585 configured to integrally connect the first resilient portion
581 to the second resilient portion
582. Therefore, it is unnecessary to attach individually the first resilient portion
581 and the second resilient portion
582 to the fixed core
52. In addition, it is easy to manipulate the shock absorber
58. Thus, the shock absorber
58 can be easily attached to the fixed core
52.
[0053] The core case
25 is configured to house the fixed core
52 in its front end side and the movable core
54 in its rear end side. The core case
25 includes a side wall portion
251 shaped into a circular cylindrical shape. The side wall portion
251 has its inner diameter approximately identical to the inner diameter of the through hole
232 of the closure plate
23. In addition, the core case 25 includes a bottom wall portion
252 configured to cover a rear aperture of the side wall portion
251. Further, the core case
25 includes a flange portion
253 shaped into a circular shape and formed at a front end side of the side wall portion
251. The core case
25 is attached to the closure plate
23 by bonding in an airtight manner a front surface of the flange portion
253 to a rear surface of the closure plate
23. It is noted that a center of the side wall portion
251 of the core case
25 is aligned with a center of the through hole
232 of the closure plate
23.
[0054] The shaft
53 is shaped into a round bar shape. The shaft
53 is inserted into the through hole
42 of the movable contact
40, the through hole
63 of the arc protection member
60, and an inside of the fixed core
52. That is, the shaft
53 is disposed so as to penetrate through the movable contact
40, the arc protection member
60, and the fixed core
52. The shaft
53 has its front end (first end) placed inside the sealed receptacle
20 and its rear end (second end) placed outside the sealed receptacle
20.
[0055] The shaft
53 is provided at its front end with a latch
531 being in the form of a circular disk shape. The latch
531 has its outer diameter greater than the inner diameter of the through hole
42 of the movable contact
40. Therefore, the latch
531 comes into contact with the front surface (fixed contact
31 side surface of the movable contact
40) of the movable contact
40. Therefore, the movable contact
40 moves rearward together with the shaft
53 when the shaft
53 moves rearward. The latch
531 locks the movable contact
40 in order to prevent the movable contact
40 from moving toward the fixed contact
31 by a spring force of the spring
51.
[0056] The movable core
54 is made of a magnetic material and is shaped into a circular cylindrical shape. The movable core
54 has a hole
541 which penetrates through the movable core
54 along an axial direction of the movable core
54. The rear end of the shaft
53 is inserted into the hole
541. Thereby, the movable core
54 is coupled to the rear end of the shaft
53. The movable core
54 is housed between a rear end surface of the fixed core
52 and the bottom wall portion
252 of the core case
25. A distance between the rear end surface of the fixed core
52 and the bottom wall portion of the core case
25 is selected in consideration of a distance (contact gap) between the fixed contact
31 and the contact portion
41.
[0057] A buffer member
571 is interposed between the movable core
54 and the fixed core
52. The buffer member
571 is configured to absorb impact caused when the movable core
54 comes into contact with the fixed core
52. Likewise, a buffer member
572 is interposed between the movable core
54 and the core case
25. The buffer member
572 is configured to absorb impact caused when the movable core
54 comes into contact with the bottom wall portion
252. The buffer members
571 and
572 are made of an elastic material (e.g. an elastomer such as a rubber) and are shaped into a circular annular shape.
[0058] The return spring (hereinafter abbreviated as "spring")
55 is a coil spring. The spring
55 is interposed between the cap
24 and the movable core
54. The spring
55 is greater in a spring constant than the spring
51. Therefore, the spring
55 keeps the movable core
54 away from the fixed core
52. In other words, the spring
55 presses the movable core
54 against the bottom wall portion
252. In this situation, the shaft
53 keeps the movable contact
40 away from the fixed contacts
31. That is, the movable contact
40 is placed in the off-position.
[0059] The electric magnet device
56 includes a coil
561, a coil bobbin
562, and a yoke
563. The coil bobbin
562 is configured to carry the coil
561. The coil bobbin
562 is shaped into a circular cylindrical shape. The coil bobbin
562 has its inner diameter greater than an outer diameter of the side wall portion
251 of the core case
25. The yoke
563 is made of a magnetic material, and is shaped into an approximately U-shape in order to cover a rear side, a right side, and a left side of the coil bobbin
562. The electric magnet device
56 is attached to the rear surface side of the closure plate
23 while the core case
25 is inserted into the coil bobbin
562. In the contact device
10, the fixed core
52, the movable core
54, the yoke
563, and the closure plate
23 constitute a magnetic circuit. In addition, as shown in FIG. 11, the coil
561 has its opposite ends respectively electrically connected to coil terminals
564.
[0060] When the coil
561 is energized, a magnetic attraction is generated between the fixed core
52 and the movable core
54. Thereby, the movable core
54 is moved toward the fixed core
52 against the spring force of the spring
55. That is, the electromagnet device
56 is configured to generate the magnetic attraction between the fixed core
52 and the movable core
54, thereby moving the movable core
54 toward the fixed core
52. When the movable core
54 moves towards the fixed core
52, the shaft
53 also moves forward. As a result, the latch
531 moves forward past the fixed contacts
31. In this situation, the spring force of the spring
51 allows the movable contact
40 to come into contact with the fixed contacts
31 at the predetermined contact pressure.
[0061] In the contact device
10, the spring
55 keeps the movable contact
40 in the off-position while the coil
561 is not energized. Meanwhile, the electric magnet device
56 keeps the movable contact
40 in the on-position while the coil
561 is energized. The spring
51 is interposed between the movable contact
40 and the bottom
62 so as to come into resilient contact with both the movable contact
40 and the bottom
62 irrespective of a position of the movable contact
40.
[0062] Therefore, in the contact device
10 of the present embodiment, the spring
51 holds the arc protection member
60. In other words, the spring
51 which makes the movable contact
40 come into contact with the fixed contact is used as a holding member for the arc protection member
60. Thus, according to the contact device
10, the pressing springs
1150 shown in FIG.
25 are unnecessary. As a result, it is possible to reduce the number of parts necessitated for holding the arc protection member
60 and to reduce the production cost.
[0063] In addition, the nipper portion
241 of the cap
24 is fitted into the recess
63 of the arc protection member
60. Therefore, the arc protection member
60 is positioned relative to the closure plate
23. Thus, according to the contact device
10, the arc protection member
60 can be easily assembled into the contact device
10.
[0064] Further, as described in the above, the contact device
10 includes the dust prevention member
26. Therefore, according to the contact device
10, it is possible to prevent dust from intruding into the core case
57 through the through hole
63. Thus, the dust does not prevent the movable core
54 from moving forward/rearward. For example, the aforementioned dust is dissipation particles generated by contact of the movable contact
40 with the fixed contact
31 or by separation of the movable contact
40 from the fixed contact
31. Moreover, according to the contact device
10, the dust prevention member
26 is fixed to the arc protection member
60 by use of the spring
51. Therefore, it is unnecessary to add special parts for holding the dust prevention member.
[0065] Additionally, the arc protection member
60 is provided on its bottom
62 with the positioning portion
65. Therefore, according to the contact device
10, the spring
51 can be easily attached to the arc protection member
60. Especially, the positioning portion
65 has its inner surface inclined such that the distance between the inner surface of the positioning portion
65 and the spring
51 increases as the distance from the bottom
62 increases. Therefore, the inner surface of the positioning portion
65 guides the rear end of the spring
51 to the inside of the positioning portion
65. Thus, the spring
51 can be more easily attached to the arc protection member
60. However, the positioning portion
65 does not need to have its inner surface inclined in an aforementioned manner. For example, as shown in FIGS. 8A and 8B, the inner surface of the positioning portion
65 may not be inclined.
[0066] As described in the above, the contact device
10 of the present embodiment includes the extinguishing unit
12. As shown in FIGS. 9A and 9B, the extinguishing unit
12 includes a pair of permanent magnets
121 and a yoke
122. The yoke
122 is configured to carry the pair of the permanent magnets
121. The yoke
122 is made of a magnetic metal material (e.g. an iron) and is shaped into a U-shape. The yoke
122 includes a pair of side pieces
123 which extend across the upper and lower sides of the case
21 to hold the same therebetween. The yoke
122 further includes a connection piece configured to integrally connect first ends (right ends) of the side pieces
123 in the pair. As described in the above, the side pieces
123 in the pair are connected to each other at their first ends. Therefore, the sealed receptacle
20 can be mounted inside of the yoke
122 by a manipulation of sliding the yoke
122 from right to left of the sealed receptacle
20. The permanent magnets
121 are fixed to surfaces of the side pieces
123 opposed to the sealed receptacle
20, respectively. Therefore, the permanent magnets
121 in the pair are arranged on opposite sides of the sealed receptacle
20 with respect to a direction (upward/downward direction) crossing with (perpendicular to, in the illustrated instance) a direction (lateral direction in FIG. 2A) along which the movable contact
40 moves toward and away from the fixed contact
31. The extinguishing unit
12 generates a magnetic field along the upward/downward direction. Therefore, the extinguishing unit
12 can extends an arc developed between the fixed contact
31 and the contact portion
41, thereby extinguishing the same at a short time.
[0067] As shown in FIG. 2A and 2B, the housing
13 includes a base
70 and a cover
80.
[0068] The cover
80 is shaped into a box shape having its rear surface opened. The cover
80 is attached to the base
70 to house the contacts mechanism unit
11 and the extinguishing unit
12 between the cover
80 and the base
70. As shown in FIG. 2B, the cover
80 is provided on its inner surface with a pair of holding pieces
81 configured to hold the connection piece
124 of the extinguishing unit
12 therebetween.
[0069] The contacts mechanism unit
11 is mounted on the base
70. As shown in FIGS. 10A and 10B, the base
70 is shaped into a rectangular plate shape having enough dimensions to cover a rear surface side opening of the cover
80. The base
70 includes two insertion holes
71 for the external connection terminals
34. The respective insertion holes
71 penetrate through a front end portion of the base
70. The base
70 includes two insertion holes
72 for the coil terminals
564. The respective insertion holes
72 penetrate through a rear end portion of the base
70.
[0070] In addition, two click pieces
125 and
126 are formed on the lower side piece
123 of the yoke
122 (side piece
123 adjacent to the base
70). The respective click pieces
125 and
126 extend downward from the side piece
123. The respective click pieces
125 and
126 are shaped into a rectangular plate shape. Moreover, the click pieces
125 and
126 are arranged along a longitudinal direction (lateral direction) of the side piece
123 and are spaced from each other at a predetermined distance.
[0071] The base
70 is provided on its upper surface with a pair of wall portions
73 which are parallel to each other. The wall portion
73 has its longitudinal direction parallel to the lateral direction. A clearance between the wall portions
73 defines a groove
74. The groove
74 is defined as an attachment recess into which the respective click pieces
125 and
126 are inserted. When the click pieces
125 and
126 of the extinguishing unit
12 are inserted into the groove
74, the wall portions
73 hold the respective click pieces
125 and
126 therebetween in the forward/rearward direction. The groove
74 and the click pieces
125 and
126 constitute an attachment unit configured to attach the extinguishing unit
12 to the base
70. It is noted that the attachment unit may be constituted by an attachment protrusion provided to any one of the yoke
122 and the base
70 and an attachment recess provided to the other.
[0072] Herein, the groove
74 has its right end opened. Therefore, when the extinguishing unit
12 is attached to the base
70, the click pieces
125 and
126 can be inserted into the groove
74 from a lateral side (right side) instead of an upper side. In brief, the extinguishing unit
12 can be attached to the base
70 by sliding the extinguishing unit
12 from right to left of the base
70. Further, as described in the above, the sealed receptacle
20 can be mounted inside the yoke
122 by sliding the yoke
122 from right to left of the sealed receptacle
20. Accordingly, the extinguishing unit
12 can be attached to the base after the contacts mechanism unit
11 is mounted on the base
70, as shown in FIG. 11.
[0073] Additionally, a latching protrusion
75 for preventing detachment of the extinguishing unit
12 is formed on a bottom of the groove
74. The latching protrusion
75 is configured such that a left side surface of the latching protrusion
75 comes into contact with a right side surface of the click piece
126 when the extinguishing unit
12 is placed in a predetermined position relative to the base
70. In other words, the latching protrusion
75 locks the click piece
126 such that the extinguishing unit
12 is kept placed in the predetermined position. Therefore, the extinguishing unit
12 is not allowed to move towards a direction (direction where the extinguishing unit
12 is detached from the base
70) opposed to a direction where the extinguishing unit
12 is attached to the base
70 after being placed in the predetermined position.
[0074] In the following, an explanation is made to a process of housing the contacts mechanism unit
11 and the extinguishing unit
12 in the housing
13. First, as shown in FIG. 11, the contacts mechanism unit
11 is mounted on the base
70. In this situation, the external connection terminals
34 and the coil terminals
564 are pressed into the insertion holes
71 and
72 of the base
70, respectively. Next, as shown in FIG. 12, the click pieces
125 and
126 are inserted into the groove
74 from one end side (right end side) of the base
70 by sliding the extinguishing unit
12 along a width direction of the base
70. Thereby, the extinguishing unit
12 is attached to the base
70. In this process, the click piece
126 rides over the latching protrusion
75 to be locked by the latching protrusion
75. Subsequently, after the contacts mechanism unit
11 and the extinguishing unit
12 are attached to the base
70 as shown in FIGS. 13A and 13B, the cover
80 is attached to the base
70 so as to cover the contacts mechanism unit
11 and the extinguishing unit
12.
[0075] By the way, the prior contact device is assembled by attaching the contacts mechanism unit to the base and subsequently attaching the cover to the base. In this situation, the extinguishing unit is not still attached to the base. Therefore, it is difficult to insert the connection piece of the yoke of the extinguishing unit between the holding pieces in the pair when attaching the cover to the base. Thus, the extinguishing unit can not be easily assembled into the housing.
[0076] By contrast, in the contact device
10 of the present embodiment, the extinguishing unit
12 can be attached to the base
70 by inserting the click pieces
125 and
126 into the groove
74 of the base
70. Therefore, the extinguishing unit
12 is positioned relative to the base
70 before the cover
80 is attached to the base
70. Thus, it is possible to easily inert the connection piece
124 of the extinguishing unit
12 between the holding pieces
81 of the pair of the cover
80. Consequently, the extinguishing unit
12 can be easily assembled into the housing
13. In the aforementioned instance, the yoke
122 is provided with the click pieces
125 and
126 as the attachment protrusions. Such the attachment protrusions may be provided to the base
70. With this arrangement, the groove
74 as the attachment recess is provided to the base
70, rather than the yoke
122. In other words, any one of the yoke
122 and the base
70 may include the attachment protrusion and the other may include the attachment recess configured to receive the attachment protrusion.
[0077] By the way, the latching protrusion
75 is provided at its front end with an inclined surface
76. The inclined surface
76 is inclined so as to lower its right end relative to its left end. In addition, the click piece
126 is provided at its front end with an inclined surface
127. The inclined surface
127 is inclined so as to raise its left end relative to its right end. The inclined surface
76 of the latching protrusion
75 and the inclined surface
127 of the click piece
126 are arranged to come into contact with each other when the extinguishing unit
12 is attached to the base
70 (the inclined surface
76 of the latching protrusion
75 and the inclined surface
127 of the click piece
126 are opposed to each other in a slide direction of the extinguishing unit
12). Therefore, the click piece
126 can easily ride over the latching protrusion
75 when the extinguishing unit
12 is slid to be attached to the base
70. Thus, the extinguishing unit
12 can be easily attached to the base
70.
[0078] As mentioned in the above, the latching protrusion
75 is provided with the inclined surface
76 at a portion which is opposed to the click piece
126 in the slide direction of the extinguishing unit
12. The inclined surface
76 guides the click piece
126 such that the click piece
126 rides over the latching protrusion
75. Therefore, the click piece
126 can easily ride over the latching protrusion
75 when the extinguishing unit
12 is attached to the base
70. Thus, the extinguishing unit
12 can be easily housed in the housing
13.
[0079] Moreover, the click piece
126 is provided with the inclined surface
127 at a portion which is opposed to the latching protrusion
75 in the slide direction of the extinguishing unit
12. The inclined surface
127 guides the latching protrusion
75 such that the click piece
126 rides over the latching protrusion
75. Therefore, the click piece
126 can easily ride over the latching protrusion
75 when the extinguishing unit
12 is attached to the base
70.
[0080] If the inclined surface
127 is provided to the click piece
126, it is unnecessary to provide the inclined surface
76 to the latching protrusion
75. Likewise, if the inclined surface
76 is provided to the latching protrusion
75, it is unnecessary to provide the inclined surface
127 to the click piece
126.
[0081] In addition, guide surfaces
77 are formed at right ends of both inner surfaces of the groove
74, respectively. The guide surface
77 is configured to guide the click piece
126 into the groove
74. The guide surface
77 is an inclined surface which is inclined such that a width of the groove
74 is made greater towards one end (right end) of the groove
74 than at the other end. The guide surface
77 allows the click piece
126 to be easily inserted into the groove
74. Therefore, according to the contact device
10, the extinguishing unit
12 can be easily housed in the housing
13.
[0082] Respective FIGS 14A and 14B show a modification of the contact device
10 of the present embodiment. In FIGS. 14A and 14B, the positioning portion
65 is shaped into a cylindrical shape (circular cylindrical shape, in the illustrated instance) having enough dimensions to be inserted into the inside of the spring
51. Also in this modification, the spring
51 can be easily attached to the arc protection member
60. In addition, as shown in FIGS. 14C and 14D, the positioning portion
65 is preferred to have its outer surface inclined such that a distance between the outer surface and the spring
51 increases as a distance from the bottom
62 of the arc protection member
60 increases. In other words, the positioning portion
65 is preferred to be shaped to have a tapered shape. In this situation, the outer surface of the positioning portion
65 guides the spring
51 to the inside of the positioning portion
65. Therefore, the spring
51 can be more easily attached to the arc protection member
60. The positioning portion
65 is not always required to have a cylindrical shape. The positioning portion
65 may be defined by a plurality of protrusions configured to be inserted into the inside of the spring
51.
[0083] Besides, in the contact device
10, the nipper portion
241 of the cap
24 is shaped into a rectangular shape. Therefore, according to the contact device
10, it is possible to position the arc protection member
60 without rotating. Meanwhile, in the prior contact device
1000, the peripheral wall
1141 of the arc protection member
1140 is only pressed against an inner surface of the contact case
1110. Therefore, according to the prior contact device
1000, it is necessary to house the arc protection member
1140 in the sealed receptacle
1100 while adjusting a deviation caused by rotation of the arc protection member
1140. According to the contact device
10 of the present embodiment, it is unnecessary to house the arc protection member
60 in the sealed receptacle
20 while adjusting a deviation caused by rotation of the arc protection member
60. Thus, the contact device
10 can be easily assembled. As a result, it is possible to reduce the production cost of the contact device
10.
[0084] Respective FIGS. 15A to 15C show a modification of the contact device
10 of the present embodiment. In FIGS. 15A to 15C, the cap
24A is shaped into a circular disk shape.
[0085] In the modification shown in FIG. 15A, a protrusion
233 for positioning is formed on the front surface of the closure plate
23. The protrusion
233 is shaped to be fitted into the recess
64. The protrusion
233 is formed through a process of striking a center portion of the closure plate
23 to protrude it forwardly, for example. In the modification shown in FIG. 15A, the cap
24A is provided to a front surface of the protrusion
233. Also in this situation, the arc protection member
60 can be unrotatably positioned relative to the closure plate
23 by engagement of the protrusion
233 into the recess
64.
[0086] In the modification shown in FIG. 15B, two circular protrusions
244 and
245 for positioning extends from the front surface of the cap
24A. Meanwhile, two recesses
641 and
642 for positioning are formed in the rear surface of the bottom
62 of the arc protection member
60. The recesses
641 and
642 are corresponding to the protrusions
244 and
245, respectively. Therefore, in the modification shown in FIG. 15B, the arc protection member
60 is positioned relative to the closure plate
23 by engagement of the protrusion
244 and the recess
641 together with engagement of the protrusion
245 and the recess
642. Although each of the protrusions
244 and
245 has a circular shape, a plurality of the protrusions
244 and
245 can prevent rotation of the arc protection member
60. Besides, a plurality of the protrusions for positioning may be formed on the cap
24 instead of the closure plate
23.
[0087] In the modification shown in FIG. 15C, the closure plate
23 is provided on its front surface with a protrusion (first protrusion for positioning)
234 for positioning. The bottom
62 of the arc protection member
60 is provided in its rear surface with a recess (first recess for positioning recess)
643 for positioning configured to receive the protrusion
234. Additionally, in the modification shown in FIG. 15C, the cap
24A is defined as the second protrusion for positioning. The bottom
62 is provided in its rear surface with a recess (second recess for positioning)
644 for positioning configured to receive the cap
24A. Therefore, in the modification shown in FIG. 15C, the arc protection member
60 is positioned relative to the closure plate
23 by engagement of the protrusion
234 and the recess
643 together with engagement of the cap
24A and the recess
644. Although each of the cap
24A and the protrusion
234 has a circular shape, a plurality of the cap
24A and the protrusion
234 can prevent rotation of the arc protection member
60.
[0088] Moreover, in contrast to the aforementioned instance, the arc protection member
60 may include a protrusion for positioning, and the closure plate
23 or the cap
24 may include a recess for positioning into which the protrusion for positioning of the arc protection member
60 is fitted. The closure plate
23 may include plural protrusions for positioning or plural recesses for positioning.
[0089] Respective FIGS. 16 to 19 show a modification of the shock absorber
58. In the shock absorber
58 shown in FIGS. 16A and 16B, the second resilient portion
582 includes a cutout
586 communicating with the through hole
584. The cutout
586 is of a semielliptical shape having its width decreasing as an increase of a distance from the center of the second resilient portion
582. According to the shock absorber
58 shown in FIGS. 16A and 16B, the through hole
584 can easily expand due to resilient deformability given to the second resilient portion
582. Therefore, the shock absorber
58 can be more easily attached to the fixed core
52. In addition, a used amount of a material for the shock absorber
58 can be reduced by an amount of material corresponding to the cutout
586. Thus, the production cost can be reduced. Besides, a shape of the cutout
586 is not limited to the aforementioned instance. For example, as the shock absorber
58 shown in FIGS. 16C and 16D, the cutout
586 may extend to the outer edge of the second resilient portion
582. Alternately, as the shock absorber
58 shown in FIGS. 16E and 16F, the first resilient portion
581 also may be provided with a cutout
587 in a similar manner as the second resilient portion
582. With this arrangement, the cutout
587 of the first resilient portion
581 communicates with the cutout
586 of the second resilient portion
582.
[0090] In brief, it is sufficient that at least one of the first resilient portion
581 and the second resilient portion
582 is provided with a cutout communicating with the through holes
583 and
584 thereof.
[0091] In the shock absorber
58 shown in FIG. 17, the first resilient portion
581 is provided on its front surface with four protruded portions
588A. The protruded portions
588A are each shaped into a circular shape, and are arranged at regular intervals along a circumferential direction of the first resilient portion
581. In addition, the second resilient portion
582 is provided on its rear surface with four protruded portions
588B. The protruded portions
588B are each shaped into a circular shape, and are arranged at regular intervals along a circumferential direction of the first resilient portion
582. Besides, the number of the protruded portions
588A and the number of the protruded portions
588B are not limited to four. For example, the number of the protruded portions
588A and the number of the protruded portions
588B may be one to three, or more than four.
[0092] According to the shock absorber
58 shown in FIG. 17, the protruded portions
588A decrease a contact area of the first resilient portion
581 and the cap
24 relative to that of the shock absorber
58 shown in FIG. 16, and the protruded portions
588B decrease a contact area of the second resilient portion
582 and the closure plate
23 relative to that of the shock absorber
58 shown in FIG. 16. Therefore, a vibration caused by contact of the movable core
54 with the fixed core
52 is restrained from being transmitted to the cap
24 and the closure plate
23. Consequently, according to the contact device
10 having the shock absorber
58 shown in FIG. 17, it is possible to more reduce an operation noise of the contact device
10 by reducing the vibration transmitted outside.
[0093] In the shock absorber
58 shown in FIG. 18, the first resilient portion
581 is provided in its front surface with four recessed portions
589A. The recessed portions
589A are arranged at regular intervals along a circumferential direction of the first resilient portion
581. In addition, the second resilient portion
582 is provided in its rear surface with four recessed portions
589B. The recessed portions
589B are arranged at regular intervals along a circumferential direction of the second resilient portion
582. Besides, the number of the recessed portions
589A and the number of the recessed portions
589B are not limited to four. For example, the number of the recessed portions
589A and the number of the recessed portions
589B may be one to three, or more than four.
[0094] Also according to the shock absorber
58 shown in FIG. 18, the recessed portions
589A decrease the contact area of the first resilient portion
581 and the cap
24 relative to that of the shock absorber
58 shown in FIG. 16, and the recessed portions
589B decrease the contact area of the second resilient portion
582 and the closure plate
23 relative to that of the shock absorber
58 shown in FIG. 16. Therefore, according to the contact device
10 having the shock absorber
58 shown in FIG. 18, it is possible to more reduce the operation noise of the contact device
10.
[0095] In brief, it is sufficient that the protruded portions
588A or the recessed portions
589A are provided to a surface of the first resilient portion
581 opposed to the cap
24 and that the protruded portions
588B or the recessed portions
589B are provided to a surface of the second resilient portion
582 opposed to the closure plate
23.
[0096] In the shock absorber
58 shown in FIG. 19, the first resilient portion
581 is provided on its front surface (surface opposed to the cap
24) with a protruded portion
588C, and the second resilient portion
582 is provided on its rear surface (surface opposed to the closure plate
23) with a protruded portion
588D. The protruded portion
588C, being of an annular shape, extends around an inner periphery of the first resilient portion
581. This protruded portion
588C is defined as a periphery wall surrounding the through hole
583. The protruded portion
588D, being of an annular shape, extends around an inner periphery of the second resilient portion
582. This protruded portion
588D is defined as a periphery wall surrounding the through hole
584.
[0097] In brief, it is sufficient that the first resilient portion
581 includes a periphery wall surrounding the through hole
583 and that the second resilient portion
582 includes a periphery wall surrounding the through hole
584.
[0098] In the shock absorber
58 shown in FIG. 19, the protruded portion
588C comes into contact with the cap
24 and the protruded portion
588D comes into contact with the closure plate
23.
[0099] Therefore, it is possible to prevent a dust
2000 from coming into the inside of the core case
25 (especially, a clearance between the fixed core
52 and the movable core
54) via the through holes
583 and
584. Thus, it is possible to improve reliability of an on-off operation of the contact device
10. For example, the dust
2000 is dissipation particles generated by contact of the contact portion
41 with the fixed contact
31 or by separation of the contact portion
41 from the fixed contact
31.
[0100] By the way, in the contact device
10 of the present embodiment, the screw hole
33 is provided to the fixed terminal
30 in order to fix the external connection terminal
34 to the fixed terminal
30. Therefore, a process of forming the screw hole
33 in the fixed terminal
30 is necessary. Generally, since the process of forming the screw hole
33 costs time, the production cost increases. Additionally, the fixed terminal
30 needs to be designed to have its diameter greater than a diameter of screw hole
33 (diameter of the fixed screw). Therefore, the fixed terminal
30 sees reduced design flexibility
[0101] Consequently, in a modification of the contact device
10 shown in FIG. 20, the fixed terminal
30 has its front end with a deformation portion
35 instead of the screw hole
33. Meanwhile, the external connection terminal
34 is provided with an insertion hole
341 having a circular shape. Prior to attaching the external connection terminal
34 to the fixed terminal
30, the deformation portion
35 keeps its original columnar shape with its outer diameter being smaller than an inner diameter of the insertion hole
341.
[0102] When the external connection terminal
34 is attached to the fixed terminal
30, first, the deformation portion
35 is inserted into the insertion hole
341 of the external connection terminal
34 as shown in FIG. 21A. Next, as shown in FIG. 21B, the deformation portion
35 is plastically deformed to come into close contact with an inner periphery of the insertion hole
341. In other words, the deformation portion
35 and the insertion hole
341 are used for riveting (e.g. spin riveting and radial riveting). In a situation shown in FIG. 21B, a most part of the deformation portion
35 is plastically deformed. However, a part of the deformation portion
35 which comes into contact with inner periphery of the insertion hole
341 is elastically deformed, rather than is plastically deformed. Therefore, the deformation portion
35 comes into strongly close contact with the inner periphery of the insertion hole
341. Thus, the external connection terminal
34 is fixed successfully to the fixed terminal
30. Additionally, conduction between the external connection terminal
34 and the fixed terminal
30 is successfully made because contact resistance between the external connection terminal
34 and the fixed terminal
30 decreases.
[0103] As mentioned in the above, in the modification shown in FIG. 20, the fixed terminal
30 is provided with the deformation portion
35 at its front end. The deformation portion
35 is plastically deformed to fix the external connection terminal
34 to the fixed terminal
30. That is, the fixed terminal
30 is secured to the external connection terminal
34 by plastically and elastically deforming a part of the fixed terminal
30. Therefore, the external connection terminal
34 is not necessitated to be screwed to the fixed terminal
30. According to the modification shown in FIG. 20, the process of forming the screw hole
33 in the fixed terminal
30 can be eliminated, and therefore the production cost can be reduced. Additionally, it is possible to improve the flexibility of the design of the fixed terminal
30 because the diameter of the fixed terminal
30 is independent from the diameter of the screw hole
33.
[0104] Especially, the deformation portion
35 is a protrusion extending from the fixed terminal
30 toward the external connection terminal
34. The insertion hole
341 defined as an insertion portion into which the deformation portion
35 is inserted is formed in the external connection terminal
34. Therefore, the external connection terminal
34 can be riveted to the fixed terminal
30 with the deformation portion
35 being inserted into the insertion hole
341 followed by being plastically deformed. Consequently, the external connection terminal
34 can be easily fixed to the fixed terminal
30.
[0105] In addition, a tapered surface
342 is formed in a periphery of the insertion hole
341. The tapered surface
342 expands the insertion hole
341 to be greater towards its front side (side opposed to the fixed core
52) than at its rear end. Therefore, when the deformation portion
35 is plastically deformed, the deformation portion
35 is deformed to come into close contact with the tapered surface
342. A contact area between the external connection terminal
34 and the deformation portion
35 can be increased by forming the tapered surface
342. Consequently, it is possible to prevent the external connection terminal
34 from rotating around the deformation portion
35. Further, the contact resistance between the external connection terminal
34 and the fixed terminal
30 can be more decreased. It is noted that the tapered surface
342 does not need to be formed in the external connection terminal
34 (see FIGS. 22A to 22C). However, in view of the above merits, the tapered surface
342 is preferred to be formed.
[0106] In an instance shown in FIG. 23D, a junction between the fixed terminal
30 and the external connection terminal
34 has poor resistance to a stress applied along a circumference direction of the insertion hole
341. This is caused by the inner peripheral shape of the insertion hole
341 of the external connection terminal
34 being a precise circular shape. In the instance shown in FIG. 23D, when stress is applied along the circumference direction of the insertion hole
341 to the external connection terminal
34, the external connection terminal
34 is likely to rotate around the fixed terminal
30.
[0107] In view of the above, as shown in FIG. 23A, the insertion hole
341 may have its inner peripheral shape being an elliptical shape. With this arrangement, the junction between the fixed terminal
30 and the external connection terminal
34 has excellent resistance to a moment developed about an central axis of the fixed terminal
30 (i.e., the stress applied along the circumference direction of the insertion hole
341). Therefore, it is possible to prevent the external connection terminal
34 from rotating around the fixed terminal
30.
[0108] Shapes of the insertion hole
341 and the deformation portion
35 are not limited in the aforementioned instance. For example, as shown in FIG. 23B, the insertion hole
341 may have its inner periphery of a rectangular shape (regular tetragon shape, in the illustrated instance). Alternately, as shown in FIG. 23C, plural (four, in the illustrated instance) cutouts
344 may be formed in the inner periphery of the insertion hole
341 having a precise circular inner periphery, and may be arranged at regular intervals along the circumference direction of the insertion hole
341. In brief, when the inner peripheral shape of the insertion hole
341 is selected from any one of shapes but the precise circular shape, it is possible to prevent the external connection terminal
34 from rotating relative to the fixed terminal
30.
[0109] By the way, as shown in FIG. 22D, instead of the insertion hole
341, a cutout
343 may be formed in the external connection terminal
34. The cutout
343 communicates with an outside of the external connection terminal
34 at one width end of the external connection terminal
34. Also in this situation, the external connection terminal
34 can be fixed to the fixed terminal
30 by use of the deformation portion
35 and the cutout
343. Especially, it is possible to improve workability of the riveting process, because the deformation portion
35 can easily pass through the cutout
343 rather than the insertion hole
341.
[0110] In a modification shown in FIGS. 24A and 24B, the fixed terminal
30 is provided at its front end with two deformation portions
35. Additionally, the external connection terminal
34 includes two insertion holes
341 respectively corresponding to the two deformation portions
35.
[0111] With this arrangement, it is possible to prevent the external connection terminal
34 from rotating around the fixed terminal
30. Besides, as shown in FIG. 24C, the cutout
343 may be formed instead of the two insertion holes
341. Also with this arrangement, the external connection terminal
34 is fixed to the fixed terminal
30 by use of the two deformation portions
35 and the cutout
343. Especially, it is possible to improve workability of the riveting process, because the deformation portion
35 can easily pass through the cutout
343 rather than the insertion hole
341. Besides, the number of the deformation portions
35 and the number of the insertion holes
341 may be three or more.
[0112] In another respect, the aforementioned contact device
10 of the present embodiment is defined as follows. That is, the contact device
10 includes the sealed receptacle
20 configured to house the fixed contact
31 and the movable contact
40, and the drive unit
50 configured to move the movable contact
40 between the on-position where the movable contact
40 is kept in contact with the fixed contact
31 and the off-position where the movable contact
40 is kept away from the fixed contact
31. The sealed receptacle
20 includes the case
21 made of dielectric materials and the closure plate
23. The case
21 is provided with the aperture
211 in its rear wall (first wall). The closure plate
23 is secured in an airtight manner to the periphery of the aperture
211 of the case
21. The fixed contact
31 is fixed to the front wall (second wall) of the case
21 which is opposed to the rear wall of the case
21. The movable contact
40 is interposed between the fixed contact
31 and the closure plate
23. The drive unit
50 includes the shaft
53, and the actuator including the fixed core
52 penetrating through the closure plate
23, the movable core
54, and the electromagnet device
56. The shaft
53 is disposed to penetrate through the movable contact
40 and the fixed core
52. The shaft
53 is provided at its front end (first end) inside the sealed receptacle
20 with the latch
531 coming into contact with the fixed contact
31 side surface of the movable contact
40. The shaft
53 has its rear end (second end) outside the sealed receptacle
20 coupled (secured) to the movable core
54. The electromagnet device
56 is configured to generate a magnetic attraction between the fixed core
52 and the movable core
54. The aforementioned actuator is configured to control the electromagnet device
56 to move the shaft
53 along its axial direction between the position where the latch
531 separates the movable contact
40 from the fixed contact
31 and the position where the latch
531 allows the movable contact
40 to come into contact with the fixed contact
31. The fixed core
52 is provided with the flange
521 configured to be hooked over the periphery of the through hole
232 of the closure plate
23 through which the fixed core
52 penetrates. The contact device
10 includes the cap
24 secured to the closure plate
23 such that the flange
521 of the fixed core
52 is held between the cap
24 and the closure plate
23. The contact device
10 further includes the shock absorber
58. The shock absorber
58 includes the first resilient portion
581, the second resilient portion
582, and the connection portion
585. The first resilient portion
581 is interposed between the flange
521 of the fixed core
52 and the cap
24. The second resilient portion
582 is interposed between the flange
521 of the fixed core
52 and the closure plate
23. The connection portion
585 is configured to integrally connect the outer edge of the first resilient portion
581 to the outer edge of the second resilient portion
582.
[0113] Therefore, according to the contact device
10, it is unnecessary to attach individually the first resilient portion
581 and the second resilient portion
582 to the fixed core
52. Thus, the shock absorber
58 can be easily attached to the fixed core
52. Moreover, since the first resilient portion
581 and the second resilient portion
582 which each have poor manipulability are integrally connected to each other through the connection portion, it is easy to manipulate the shock absorber
58.
[0114] In another respect, the aforementioned contact device
10 of the present embodiment is defined as follows. That is, the contact device
10 includes the contacts mechanism unit
11, the extinguishing unit
12, and the housing
13. The contacts mechanism unit
11 includes the sealed receptacle
20 and the drive unit
50. The sealed receptacle
20 is configured to house the fixed contact
31 and the movable contact
40. The drive unit
50 is configured to move the movable contact
40 between the on-position where the movable contact
40 is kept in contact with the fixed contact
31 and the off-position where the movable contact
40 is kept away from the fixed contact
31. The extinguishing unit
12 includes the pair of the permanent magnets
121 and the yoke
122 configured to hold the pair of the permanent magnets
121. The permanent magnets
121 in the pair are arranged on opposite sides of the sealed receptacle
20 with respect to the direction crossing with the direction along which the movable contact
40 moves toward and away from the fixed contact
31. The housing
13 includes the base
70 on which the contacts mechanism unit
11 is mounted, and the cover
80 configured to be attached to the base
70 such that the contacts mechanism unit
11 and the extinguishing unit
12 are housed between the base
70 and the cover
80. The any one of the yoke
122 and the base
70 is provided with the attachment protrusion with the other being provided with the attachment recess configured to receive the attachment protrusion.
[0115] According to this configuration, the contact device
10 can be easily assembled.
[0116] In another respect, the contact device
10 shown in FIG. 20 is defined as follows. That is, the contact device
10 includes a sealed unit and the drive unit
50. The sealed unit includes the fixed contact
31, the movable contact
40, and the sealed receptacle
20 configured to house the fixed contact
31 and the movable contact
40. The drive unit
50 is configured to move the movable contact
40 between the on-position where the movable contact
40 is kept in contact with the fixed contact
31 and the off-position where the movable contact
40 is kept away from the fixed contact
31. The sealed unit includes the fixed terminal
30 penetrating through the wall (front wall) of the sealed receptacle
20, and the external connection terminal
34 adapted to be connected to an external circuit. The fixed terminal
30 is provided with the fixed contact
31 at its rear end (first end) inside the sealed receptacle
20. In addition, the fixed terminal
30 is provided with the deformation portion
35 at its front end (second end) outside the sealed receptacle
20. The deformation portion
35 is adapted to be plastically deformed to connect the external connection terminal
34 to the fixed terminal
30.
[0117] Therefore, according to the contact device
10 shown in FIG. 20, the external connection terminal
34 is not necessitated to be screwed to the fixed terminal
30. Thus, the process of forming the screw hole
33 in the fixed terminal
30 can be eliminated, and therefore the production cost can be reduced. Additionally, it is possible to improve the flexibility of the design of the fixed terminal
30 because the diameter of the fixed terminal
30 is independent from the diameter of the screw hole
33.