Cross-Reference to Related Applications
Technical Field
[0002] The present invention relates to a drip-proof structure of an electronic component.
Background Art
[0003] A rotary electronic component is known in which a portion of an outer periphery of
a rotary body of is exposed as an operating portion to the outside through an opening
provided on an outer case, and an electrical function portion in a main case is driven
by rotationally operating the operating portion with a finger etc. so as to cause
a change in an output from the electrical function portion. In the rotary electronic
component, a drip-proof structure of an electronic component is known in which a rubbery
drip-proof sheet is installed so as to seal a gap between the opening and the rotary
body to prevent a liquid from entering through the gap between the opening and the
rotary body to contact with the electrical function portion (see, e.g.,
JP 2011/134573 A).
[0004] Another drip-proof structure of an electronic component is known in which an electrical
function portion is covered with a waterproof case etc. to prevent liquid from contacting
with the electrical function portion (see, e.g.,
JP 2010/9937 A).
Citation List
Patent Literatures
[0006] US 3 809 830 A discloses a thumb selector switch structure which is particularly suitable for use
in corrosive or dusty environments. The selector switch includes a printed circuit
panel having an angularly encoded conductive pattern printed thereon. A rotatable
contact carrying indicia wheel is rotatably mounted to the printed circuit panel so
that the contacts carried by the indicia wheel selectively engage various portions
of the angularly encoded printed circuit pattern, thereby producing digital output
signals in response to the rotation of the contact carrying wheel. The contact carrying
wheel is permanently hermetically sealed to the printed circuit board by means of
a clear plastic casing. An actuator wheel is provided for rotating the indicia and
contact carrying wheel. A suitable housing having a detent spring mounted therein
is provided to enclose the above described structure.
[0007] WO 2015/087366 A1 discloses a component to effectively carry out waterproofing, while avoiding cramping
an internal space to the extent it is possible to do so. The component is provided
with: a light source ; a moveable part having a first window; a circuit board; and
a housing in which is formed an opening through which the surface of the moving part
protrudes. The housing, in combination with the moveable part, has dividing walls
for dividing the internal space of the housing into a first space and a second space.
The dividing walls support the moveable part, and the light source illuminates the
first window through a portion of the dividing walls, which are formed by transmissive
members.
Summary of Invention
Technical Problem
[0008] The drip-proof structure of an electronic component disclosed in
JP 2011/134573 A may be poor in operability of the operating portion since the rubbery drip-proof
sheet is in contact with the rotary body.
[0009] Also, concerning the drip-proof structure of the electronic component disclosed in
JP 2010/9937 A, since it is necessary to separately provide the waterproof case etc., the number
of components may increase and the size of the rotary electronic component itself
may also increase.
[0010] It is an object of the invention to provide a drip-proof structure of an electronic
component that is effective in drip-proofness and excellent in operability of the
operating portion and allows downsizing of the component.
Solution to Problem
[0011] According to the present invention a drip-proof structure of an electronic component
as defined by claim 1 is provided. The dependent claims define embodiments of the
invention.
Advantageous Effects of Invention
[0012] According to the invention, a drip-proof structure of an electronic component can
be provided that is effective in drip-proofness and excellent in operability of the
operating portion and allows downsizing of the component.
Brief Description of Drawings
[0013]
FIG. 1 is a perspective view showing a rotary electronic component in an embodiment.
FIG. 2 is a cross sectional view showing the rotary electronic component taken along a line
A-A in FIG. 1.
FIG. 3 is an exploded perspective view showing a main unit, a cover and drip-proof members.
FIG. 4 is an exploded perspective view showing the state in which the cover is detached
from the rotary electronic component.
FIG. 5 is an exploded perspective view showing the main unit.
FIG. 6 is an exploded perspective view showing the main unit when viewed at an angle different
from FIG. 5.
FIG. 7 is a perspective view showing the back of the cover.
FIG. 8 is a cross sectional view showing a liquid ingress path into the rotary electronic
component.
Description of Embodiments
[0014] An embodiment of the invention will be described below in reference to the drawings.
FIG. 1 is a perspective view showing an electronic component (hereinafter, referred to as
"rotary electronic component")
1 configured using an embodiment of the present invention,
FIG. 2 is a cross sectional view showing the rotary electronic component
1 (a cross section taken along the line A-A in
FIG. 1), FIG. 3 is an exploded perspective view showing a main unit
10, a cover
300 and drip-proof members (hereinafter, referred to as "packings")
250 that constitute the rotary electronic component
1, FIG. 4 is a perspective view showing a process of attaching the packings
250 and the cover
300 to the main unit
10, FIG. 5 is an exploded perspective view showing the main unit
10, and
FIG. 6 is an exploded perspective view showing the main unit
10 when viewed at another angle. As shown in these drawings, the rotary electronic component
1 is provided with the main unit
10 housing various parts, and the cover
300 covering a surface of the main unit
10 on the side where an rotary body (hereinafter, referred to as operating knob 100)
protrudes. . In the following description, "upper/upward" is a direction to view the
cover
300 from the main unit
10, and "lower/downward" is a direction opposite thereto. In addition, "front/forward"
is a direction to view the operating knob
100 from a first case
20 (described later), and "rear/rearward" is a direction to view a circuit board
160 (described later) from the first case
20.
[0015] As shown in
FIGS. 1 to
6, the main unit
10 is configured that the operating knob
100 as a rotary body, with a sliding piece
130 attached thereto, is housed between the first case
20 and a second case
70, a terminal unit
140 is housed in the first case
20 on the opposite side, and the circuit board
160, a light guide
190 and a third case
220 are provided thereon. The rotary electronic component
1 is formed by attaching the packings
250 and the cover
300 to the main unit
10.
[0016] The first case
20 is a molded article formed by molding a synthetic resin into a substantially rectangular
box shape, and has a substantially cylindrical bearing
21 at the upper center, a first housing portion
23 as a recess provided on the operating knob
100 side of the bearing
21, and a second housing portion
25 as a recess provided on the circuit board
160 side. A pair of engagement portions
27, which are rectangular through-holes to be engaged with claw portions
79 of the second case
70 (described later), are provided on both right and left side surfaces of the first
case
20 at positions on the first housing portion
23 side. Meanwhile, a pair of engagement portions
29, which are rectangular through-holes to be engaged with claw portions
223 of the third case
220 (described later), are formed on both the right and left side surfaces of the first
case
20 at positions on the second housing portion
25 side. In addition, a pair of claw-shaped engaging portions
30, which engage in engagement portions
309 of the cover
300 (described later), are formed both the right and left side surfaces of the first
case
20 at positions between the engagement portions
27 and
29. A terminal unit housing portion
31, which has a substantially rectangular shape and opens rearward, is formed under the
bearing
21. An arc surface portion of the bearing
21 at the middle of the upper surface and the upper surface portions located on right
and left sides of the arc surface portion and protruding toward the first housing
portion
23 serve as drip-proof member-mounting surfaces (hereinafter, referred to as "packing
mounting surfaces")
33 (33a to
33c), where the arc surface portion is defined as a bearing-side drip-proof member-mounting
surface
33a, and linear portions on both sides thereof are defined as right- and left-side packing
mounting surfaces
33b and
33c. In addition, a pair of right and left stopper engaging portions
35 (only one is shown in
FIG. 5) are formed, which butt against a stopper
129 of the operating knob
100 (described later) and prevent the stopper
129 from moving upward therebeyond. In addition, although it is not shown in the drawings,
a click engaging portion composed of raised and recessed portions along an arc direction
(a direction of the arc along which a click ball
127 moves (described later)) is formed in the first housing portion
23 at a lower portion (at a position facing the click ball
127) of a surface on which the bearing
21 is provided.
[0017] The second case
70 is formed in a single piece by molding a synthetic resin and has a case main body
71 having a substantially rectangular plate shape and a circular plate-shaped knob supporting
portion
73 which protrudes from the upper center of the case main body
71 toward the operating knob
100. The knob supporting portion
73 is configured that an outer peripheral portion protruding from a surface on the operating
knob
100 side is a cylindrical protruding portion
74 constituting a part of the drip-proof portion, and a protruding portion
75 having a bottomed cylinder shape is provided at the center inside the protruding
portion
74. A pair of engaging claws
77 protrude from both right and left side edges of the case main body
71 toward the operating knob
100. The engaging claws
77 are flat plate-shaped members on which the claw portions
79 are provided near the end portions on both outer sides (only one claw portion
79 is shown in
FIGS. 5 and
6). In addition, the upper surface of the case main body
71 serves as a non-bearing-side packing mounting surface
81 to be in contact with the packing
250 (described later).
[0018] The operating knob
100 is a molded article of a synthetic resin and is formed by comolding a transparent
material and an opaque material. The operating knob
100 has a substantially circular-plate shape and is configured that the circular outer
circumferential surface thereof serves as an operating portion
101. A circular recessed portion
103 constituting a part of the drip-proof portion is provided on a surface of the operating
knob
100 facing the second case
70, and two cylindrical protruding portions
105 and
107 are concentrically provided and protrude in the recessed portion
103. A circular recessed portion between the two protruding portions
105 and
107 is an insertion portion (recess)
109 into which the protruding portion
75 of the second case
70 is inserted. The protruding portion
74 of the knob supporting portion
73 of the second case
70 is also inserted into the recessed portion
103. The drip-proof portion by a male-female interlocking connection between the protruding
portion
74 and the recessed portion
103 is thereby formed. Meanwhile, the recessed portion in the middle of the protruding
portion
107 has a bottom surface which is recessed in a substantially cone shape and serves as
a light-reflecting surface
110. A shaft portion
111 having a substantially circular-columnar shape protrudes from the center of a side
surface (a surface facing the first case
20) of a main body
100a of the operating knob
100. An upper surface of the shaft portion
111 serves as a sliding piece attachment portion
113, and a truncated cone-shaped light-guiding protrusion
115 is further provided and protrudes from the center of the sliding piece attachment
portion
113. An end face of the light-guiding protrusion
115 serves as a light introducing surface
117. Sliding piece attaching protrusions
119 formed of small pieces sticking out are formed on the sliding piece attachment portion
113. A ring-shaped drip-proof recess
121 is formed around the shaft portion
111. A click mechanism housing portion
123 formed of a bottomed circular hole is formed on the operating knob
100 at an outer peripheral portion of a surface facing the first case
20. A coil spring
125 and the click ball
127 are housed in the click mechanism housing portion
123. A portion around the click mechanism housing portion
123 bulges outward from the outer periphery of the operating knob
100 and the bulging portion serves as the stopper
129. The operating knob
100 is formed by molding two types of resins
A1 and
A2 into a single piece, as shown in
FIG. 2. The resin
A1 is a transparent resin and the resin
A2 is an opaque resin. The whole transparent resin
A1 constitutes a light guide and is molded so that the circular outer circumferential
surface of the operating portion
101 is optically coupled to the light introducing surface
117 of the light-guiding protrusion 115.
[0019] The sliding piece
130 is formed of an elastic metal plate and is provided with a base portion
131 and arch-shaped arm portions
133 protruding from an outer surface of the base portion
131 and having a shape with U-turn at a root portion. A contact portion
135 which is curved and protrudes toward the circuit board
160 is formed at the center of each arm portion
133. Attachment holes
137 formed of small holes are also provided on the base portion
131.
[0020] The terminal unit
140 is formed by insert molding in which six metal-plate terminals
141 are molded in a substantially rectangular terminal case
143 consisting of a molding resin and a terminal holding case
145 having a substantially rectangular-prism shape. Each terminal
141 is arranged such that one end protrudes from a rear surface of the terminal case
143 so that the six ends are aligned in a row, and the other end protrudes from a side
surface of the terminal case
143, is bent downward, is fixed by the terminal holding case
145 and then protrudes from a lower surface of the terminal holding case
145 so that the six ends are aligned in a row.
[0021] The circuit board
160 is configured that a circular through-hole
163 is provided at an upper portion of an insulating substrate
161 formed of a substantially rectangular hard plate, a sliding contact pattern
165 to be in sliding contact with the contact portions
135 of the sliding piece
130 is formed on a front surface of the insulating substrate
161 around the circular through-hole
163, six terminal insertion holes
167 formed of small holes for inserting one ends of the terminals
141 are formed horizontally in a row on the insulating substrate
161 in the vicinity of the lower edge, a light-emitting element
169 is attached to the rear surface of the insulating substrate
161 so as to be located below the through-hole
163, and various other electronic parts
171 are attached to predetermined positions. A circuit pattern (not shown) is formed
on the insulating substrate
161 to electrically connect between the sliding contact pattern
165, the light-emitting element
169, the various other electronic parts
171 and the terminals
141 inserted into the terminal insertion holes
167. Various patterns such as switch pattern or resistor pattern can be used as the sliding
contact pattern
165.
[0022] The light guide
190 is formed in a single piece by molding a transparent synthetic resin into a substantially
rectangular box shape having an opening on the front side. On the front side, the
light guide
190 has a substrate housing portion
191 having a recessed shape, and a circular-columnar protruding portion
193 protrudes from an upper portion of the bottom surface of the substrate housing portion
191. The substrate housing portion
191 is formed in a shape capable of housing and covering the entire circuit board
160. The protruding portion
193 has a size capable of being inserted into the through-hole
163 of the circuit board
160 and is configured that an end face serves as a light-emitting surface
195. The upper surface of the light guide
190 also serves as a light-emitting surface 197.
[0023] The third case
220 is formed in an outer shape which is a substantially rectangular plate shape and
substantially covers the rear surface of the first case
20. A pair of engaging claws
221 protrude from both right and left sides of the third case
220 toward the first case. The engaging claws
221 are flat plate-shaped members on which the claw portions
223 are provided near the end portions on both outer sides.
[0024] As shown in
FIG. 3, the packings
250 are formed of an elastic body such as elastomer into a substantially rectangular
ring-shape with a circular cross section and form a shape in which the front side
and the right and left sides are linear and the rear side has a curved portion which
is curved upward in an arc shape. Here, a portion having the arc-shaped curved portion
is defined as a bearing-side packing
250a, portions on the right and left sides are defined as right- and left-side packings
250b and
250c, and a portion on the front side is defined as a non-bearing-side packing
250d. The right- and left-side packings
250b and
250c serve as coupling portions for coupling the bearing-side packing 250a to the non-bearing-side
packing
250d and contribute to improvement in assemblability and wobble prevention, in addition
to the sealing effect. The curved portion of the bearing-side packing 250a matches
the outer shape of the bearing
21 of the first case
20.
[0025] FIG. 7 is a perspective view showing the cover
300 when viewed from the rear lower side. As shown in
FIGS. 7 and also
FIGS. 2 and
3, the cover
300 is a molded article of a synthetic resin and is formed in a substantially rectangular
box shape having an opening on the lower side so that a case main body-housing portion
301 for covering and housing the upper portion of the main unit
10 is formed on the lower side of the cover
300. On an upper surface (outside surface)
303 of the cover
300, an exposure opening
305 for exposing a portion of the operating portion
101 of the operating knob
100 is formed at a position facing the operating knob
100 and an illumination portion
307 is formed at a position facing the light-emitting surface
197 of the light guide
190. The illumination portion
307 is formed by cutting a desired shape, such as letter/character or symbol, out of
an opaque coating material applied to a surface of a transparent molded resin constituting
the cover
300, but may be formed by other methods. The engagement portions
309, which are rectangular through-holes to be engaged with the engaging portions
30 of the first case
20, are respectively formed on both the right and left side surfaces of the cover
300. Drip-proof member-mounting surfaces (hereinafter, referred to as "packing mounting
surfaces")
311 (311a to
311d) are formed on the back surface of the cover
300 so as to surround the exposure opening
305. The packing mounting surfaces
311 consist of a bearing-side packing mounting surface
311a in an arc shape convex toward the exposure opening
305, linear-shaped right- and left-side packing mounting surfaces 311b and 311c on both
sides thereof
(311c is not shown), and a non-bearing-side packing mounting surface
311d having a linear shape and located on the opposite side to the bearing-side packing
mounting surface
311a, which together form one substantially rectangular ring-shaped surface (the same shape
as that formed by the packings
250). In other words, the bearing-side packing mounting surface
311a is formed at a position along the shape of an arc-shaped portion around the rim of
the exposure opening
305, and the non-bearing-side packing mounting surface 311d is formed at a position away
from the arc-shaped portion around the rim of the exposure opening 305.
[0026] Next, assembly of the rotary electronic component 1 will be described. Firstly, the
main unit 10 is assembled. In detail, the base portion 131 of the sliding piece 130
is pre-placed on the sliding piece attachment portion 113 of the operating knob 100.
At this time, the sliding piece 130 is attached by heat staking (or only press-fitting)
the tips of the sliding piece attaching protrusions
119 of the sliding piece attachment portion
113 which are inserted into the attachment holes
137 of the sliding piece
130. Also, grease G for dripproofing is applied to fill the drip-proof recess
121 of the operating knob
100. Meanwhile, the tip of each terminal
141 protruding from the rear of the terminal unit
140 is inserted into the corresponding terminal insertion hole
167 of the circuit board
160 and is fixed on the opposite side to the circuit pattern (not shown) on the circuit
board by solder h (see
FIG. 2).
[0027] Then, the operating knob
100, with the sliding piece
130 attached thereto and also the coil spring
125 and the click ball
127 housed in the click mechanism housing portion
123, is arranged to be housed in the first housing portion
23 of the first case
20 in such a manner that the shaft portion
111 of the operating knob
100 inserted into the bearing
21 of the first case
20 is rotatably supported. In this state, the bearing
21 of the first case
20 is inserted in the drip-proof recess
121 of the operating knob
100 which is filled with the grease G, and this provides a drip-proof processing portion
B1. Next, the second case
70 is attached to cover the front side surface of the operating knob
100. Once the claw portions
79 of the engaging claws
77 are engaged with the engagement portions
27 of the first case
20, the second case
70 and the first case
20 are attached to each other with the operating knob
100 sandwiched therebetween. The second case
70 is attached such that the knob supporting portion
73 covers the other side surface (the front side surface) of the operating knob
100, the protruding portion
75 is inserted into the insertion portion
109 of the operating knob
100, and the protruding portion
74 is inserted into the recessed portion
103.
[0028] Next, the circuit board
160 with the terminal unit
140 attached thereto and the light guide
190 are arranged to be housed in the second housing portion
25 of the first case
20, and the third case
220 is placed thereover. Then, the claw portions
223 of the third case
220 are respectively engaged with the engagement portions
29 of the first case
20. The main unit
10 shown in
FIG. 3 is thereby completed.
[0029] In this state, an opening
HI is formed on the upper surface between the first case
20 and the second case
70, and an opening
H2 is formed on the upper surface between the first case
20 and the third case
220 (see
FIG. 2). A portion of the operating portion
101 of the operating knob
100 is exposed (protrudes) in the opening HI. Meanwhile, the light-emitting surface
197 of the light guide
190 is exposed in the opening H2 so as to protrude externally (upward). Then, the contact
portions
135 of the sliding piece
130 are in contact with the sliding contact pattern
165 of the circuit board
160, as shown in
FIG. 2. In addition, in this state, the terminal unit
140 is housed in the terminal unit housing portion
31. Furthermore, the outer peripheral portion of the light guide
190 is in contact with a surface of the first case
20 facing the light guide
190 and encircles the circuit board
160. Furthermore, the protruding portion
193 of the light guide
190 is inserted into the through-hole 163 of the circuit board
160 so that the tip of the light-emitting surface
195 located at the end thereof closely faces the light introducing surface
117 of the operating knob
100.
[0030] Next, the packings
250 shown in
FIG. 3 are inserted into the case main body-housing portion
301 of the cover
300 and are placed in contact with the packing mounting surfaces
311 (311a to
311d) of the cover
300. Then, the cover
300 with the packings
250 installed thereon is attached to the main unit
10 from above. In other words, the upper portion of the main unit
10 is housed in the case main body-housing portion
301 of the cover
300. Then, the engaging portions
30 of the main unit
10 are respectively engaged with engagement portions
309 of the cover
300. Assembly of the rotary electronic component
1 is thereby completed. Note that, the above-mentioned assembly process is only an
example and it is obvious that various other assembly processes may be use for assembly.
For example, instead of attaching the packings
250 to the cover
300, the packings
250 may be attached to the main unit
10 which is then covered with the cover
300. In this case, ribs, etc., for preventing the packings
250 from coming out of alignment are preferably formed on at least some of the packing
mounting surfaces
33 (33a to
33c) and the non-bearing-side packing mounting surface
81 of the main unit
10.
[0031] FIG. 4 is an exploded perspective view showing the state in which only the cover
300 is detached from the assembled rotary electronic component
1. As understood from
FIG. 4, the packings
250 in the rotary electronic component
1 are in contact with the main unit
10 in the surrounding area of the hole the opening H1 which is formed by combining the
first and second cases
20 and
70. In detail, among the packings
250, the bearing-side packing
250a is in contact with the bearing-side drip-proof member-mounting surface
33a of the first case
20, the right- and left-side packings
250b and
250c are in contact with the rightand left-side packing mounting surfaces
33b and
33c of the first case
20, and the non-bearing-side packing
250d is in contact with the non-bearing-side packing mounting surface
81 of the second case
70.
[0032] Meanwhile, a portion of the operating portion
101 of the operating knob
100 is exposed through the exposure opening
305, as shown in
FIGS. 1 and
2. The light-emitting surface
197 of the light guide
190 is arranged at a position facing the lower surface (the back surface) of the illumination
portion
307 of the cover
300. Then, in the assembled state, the bearing-side packing
250a is in contact with the bearing-side packing mounting surface
311a, the right- and left-side packings
250b and
250c are in contact with the right- and left-side packing mounting surfaces
311b and
311c, and the non-bearing-side packing
250d is in contact with the non-bearing-side packing mounting surface
311d, hence, the packings 250 are sandwiched between the packing mounting surfaces
33 (33a to
33c)/the non-bearing-side packing mounting surface
81 of the main unit
10 and the cover
300 and seals between the main unit
10 and the cover
300.
[0033] In the rotary electronic component
1 assembled as described above, when the operating knob
100 is rotated, the contact portions
135 of the sliding piece
130 slide on the sliding contact pattern
165 of the circuit board
160 and this produces a difference in the detection output between the terminals
131. When rotating the operating knob
100, the grease G causes some resistance but a large torque is not required to rotate
the operating knob
100 since the packings
250 are not in contact therewith at all, hence, operability is not impaired. The operating
knob
100, when rotated, does not rotate more than about half of a turn since the stopper
129 thereof (see
FIG. 6) butts against the pair of right and left stopper engaging portions
35 (only one is shown in
FIG. 5) provided in the first housing portion
23 of the first case
20. In other words, the operating knob
100 is moves in an arc motion.
[0034] When the light-emitting element
169 is turned on, light therefrom is introduced into and reflected by the light guide
190, is then emitted from the light-emitting surface
197, and illuminates the illumination portion
307 of the cover
300 from the back side thereof, as indicated by a dot-and-dash line. On the other hand,
the light reflected inside the light guide
190 and emitted from the light-emitting surface
195 is introduced into the resin
A1 from the light introducing surface
117 of the operating knob
100, is reflected therein and guided to the circular outer circumferential surface of
the operating portion
101, and illuminates the operating portion
101.
[0035] In the meantime, the rotary electronic component 1 is installed on an operation
panel C of an electronic device, as shown in
FIG. 8. When installed, the upper surface 303 of the cover
300 is exposed, as the outside surface, to the outside of the operation panel C. Liquid
may spill on the upper surface
303 exposed to the outside of the operation panel C. The spilled liquid enters inside
the cover
300 through the exposure opening
305. The entered liquid tries to advance from the surrounding area of the operating portion
101 of the operating knob
100 toward the circuit board
160 by passing through a gap between the cover
300 and the first case
20 as indicated by an arrow LI, by passing through a gap between the cover
300 and the second case
70, moving down along the outer surface of the second case
70 and going under its lower edge and around to the opposite side of the operating knob
100 as indicated by an arrow
L2, or by passing through the opening
HI of the main unit
10 as indicated by an arrow
L3.
[0036] In the rotary electronic component 1, however, ingress of the liquid advancing toward
the circuit board
160 by passing through a gap between the cover
300 and the first case
20 as indicated by the arrow
L1 is prevented by the bearing-side packing
250a. Then, ingress of the liquid advancing toward the circuit board
160 by passing through a gap between the cover
300 and the second case
70, moving down along the outer surface of the second case
70 and going under its lower edge of and around to the opposite side of the operating
knob
100 as indicated by the arrow
L2 is prevented by the non-bearing-side packing
250d. Meanwhile, the liquid entered through the opening
H1 of the main unit
10 as indicated by the arrow
L3 passes in the surrounding area of the operating knob
100 and is directly drained downward, but the liquid advancing toward the sliding piece
130 is blocked by the drip-proof processing portion
B1 and the ingress thereof is prevented. As such, drip-proof against the liquid entering
through the exposure opening
305 of the cover
300 is effectively provided at each of these points.
[0037] As described above, the rotary electronic component 1 is configured that the operating
knob
100 moving in a circular motion (including an arc motion and an oscillatory motion) about
an axis K (see
FIG. 2) is arranged on one side of the circuit board
160, a detection means composed of the sliding piece
130 and the sliding contact pattern
165 and changing its output according to the motion of the operating knob
100 is provided between the operating knob
100 and the circuit board
160, at least the operating knob
100 is housed in the first and second cases
20 and
70, a portion of the operating portion
101 on the outer surface of the operating knob
100 is exposed through the opening
H1 provided on the first and second cases
20 and
70, the cover
300 having the exposure opening
305 for exposing the portion of the operating portion
101 of the operating knob
100 is attached to cover the outer surface of the first and second cases
20 and
70 on which the opening HI is provided, and the packings
250 are sandwiched and held between a surrounding area of the opening HI of the first
and second cases
20 and
70 and a surrounding area of the exposure opening
305 of the cover
300 and prevent ingress of liquid from the exposure opening
305 of the cover
300 through a gap between the first and second cases
20 and
70 and the cover
300.
[0038] In addition, since the shaft portion 111 provided on the operating knob
100 so as to protrude from a side surface on the circuit board
160 side is rotatably inserted into the bearing
21 protruding from the first case
20 at a position near the detection means and the drip-proof processing portion
B1 is provided at the end portion of the bearing
21 into which the shaft portion
111 is inserted, liquid which is not blocked by the packings
250 and enters the first and second cases
20 and
70 from the opening
HI of the first and second cases
20 and
70 is prevented from entering by a portion of the bearing
21 inside the first and second cases
20 and
70. Thus, it is possible to prevent ingress of liquid into the detection means and the
circuit board
160 more effectively.
[0039] The bearing-side packing
250a, which is the packing
250 arranged on the side where the surface of the operating knob
100 with the shaft portion
111 attached (the one side surface) is located, is arranged at a position along the operating
portion
101 of the operating knob
100. Thus, the bearing-side packing
250a, which is arranged on the side where the circuit board
160 is located, prevents ingress of liquid at a position in the vicinity of the operating
portion
101 of the operating knob
100 (immediately after the position of liquid ingress). On the other hand, the non-bearing-side
packing
250d, which is the packing
250 arranged on the side where the surface (the other side surface) of the operating
knob
100 opposite to the surface with the shaft portion
111 attached is located, is arranged in the vicinity of the axis K of the operating knob
100. Thus, the non-bearing-side packing
250d, which is arranged on the side where the circuit board
160 is not located, provides drip-proof protection near the center of the side surface
of the operating knob
100 which is distant from the operating portion
101 of the operating knob
100. That is, the drip-proof effect at the portion near the circuit board
160 side is enhanced by providing drip-proof protection at a position in the vicinity
of the exposure opening
305 of the cover
300. On the other hand, in a region on the opposite side of the operating knob
100 which is distant from the circuit board
160, the non-bearing-side packing
250d is arranged at a position rearward (downward) of the operating portion
101 of the operating knob
100, which allows a width dimension
S1 of a portion of the cover
300 in the vicinity of the exposure opening
305 (see
FIG. 8) to be reduced. The portion of the cover
300 in the vicinity of the exposure opening
305 is a portion exposed on the operation panel C of the electronic device when the rotary
electronic component
1 is mounted thereon. Since the width dimension S1 of such portion can be reduce, it
is possible to reduce the size or thickness, etc., of the operation panel C as well
as of the electronic device provided with the operation panel C.
[0040] It is also configured such that the circular recessed portion
103 is provided on the operating knob
100 on a surface opposite to the surface with the shaft portion
111 attached, the cylindrical protruding portion
74 to be inserted into the recessed portion
103 is provided on a surface of the second case
70 facing the surface with recessed portion
103, and the recessed portion
103 engages with the protruding portion
74. Thus, even when liquid enters through the opening
HI of the first and second cases
20 and
70, the liquid is prevented from further advancing through a gap between the second case
70 and the surface of the operating knob
100 on the opposite side to the shaft portion
111.
Reference Signs List
[0041]
- 1
- ROTARY ELECTRONIC COMPONENT (ELECTRONIC COMPONENT)
- 20
- FIRST CASE (CASE)
- 21
- BEARING
- 70
- SECOND CASE (CASE)
- 100
- OPERATING KNOB
- 101
- OPERATING PORTION
- 111
- SHAFT PORTION
- 130
- SLIDING PIECE (DETECTION MEANS)
- 160
- CIRCUIT BOARD
- 165
- SLIDING CONTACT PATTERN (DETECTION MEANS)
- 250
- PACKING (DRIP-PROOF MEMBER)
- 250a
- BEARING-SIDE PACKING (DRIP-PROOF MEMBER)
- 250d
- NON-BEARING-SIDE PACKING (DRIP-PROOF MEMBER)
- 300
- COVER
- 305
- EXPOSURE OPENING
- K1
- AXIS
- HI
- OPENING
- B1
- DRIP-PROOF PROCESSING PORTION