Field of the Invention
[0001] The present invention relates to a solenoid switch for use in a vehicle starter motor,
and a vehicle starter motor comprising such a solenoid switch.
Background Art
[0002] A starter motor for a motor vehicle normally consists of an electric motor, a transmission
mechanism, a control mechanism and so on. Upon starting an engine of the vehicle,
the electric motor generates rotating moment, and the rotating moment is transmitted
to a gear ring on the flywheel of the engine through a drive gear of the transmission
mechanism, thereby driving a crankshaft of the engine to rotate.
[0003] The control mechanism functions to control on-off of the starter motor circuit, and
control engagement and disengagement between the drive gear and the gear ring. Currently,
a widely-used control mechanism for the starter motor is a solenoid switch. Figure
1 is a structural schematic view showing a known solenoid switch for the starter motor.
The solenoid switch mainly includes: a magnetic core 4 and an electromagnetic winding
6 fixedly mounted in a housing 2; two contact posts 10 carried by a cover 8 that is
fixed on the housing 2; a plunger 16 axially movable inside the electromagnetic winding
6; a switch shaft 12 carried by and axially movable relative to the magnetic core
4 and the plunger 16; a pull rod 18 fixed on the plunger 16; a striking rod 20 fixed
in the plunger 16; a contact bridge 14 mounted on a rear end of the switch shaft 12,
and so on. A front end of the pull rod 18 is movably coupled to a shifting fork (not
shown).
[0004] A rear end of the magnetic core 4 and a front end of the cover 8 are sandwiched,
in such a manner of being opposite to each other, between a step 22 in a rear portion
of the housing 2 and a rear flanging 24 of the housing 2, and sandwiched between the
magnetic core 4 and the cover 8 is a disc spring 21 which is completely clamped axially,
without the capacity of making further axial deformation.
[0005] After a vehicle igniting switch is switched on, the electromagnetic winding 6 generates
an electromagnetic force in the plunger 16 such that the plunger 16 moves rearward
toward the magnetic core 4. The striking rod 20 drives the switch shaft 12 to together
move backwardly in an axial direction after the striking rod 20 is brought into contact
with the switch shaft 12. The contact bridge 14 is driven by the switch shaft 12 to
contact the two contact posts 10 so as to electrically connect them, thereby switching
on a main circuit of the electric motor and thus driving the electric motor to rotate.
After the contact bridge 14 is brought into contact with the two contact posts 10
and electrical connection is created between the two contact posts 10, the plunger
16 keeps on moving toward the magnetic core 4 by a certain travel until it strikes
the magnetic core 4 and is held back by the same. During this process, the front end
of the pull rod 18 pulls the transmission mechanism via the shifting fork so as to
drive the gear to move forwardly to be in engagement with the gear ring on the engine
flywheel, thereby starting the engine.
[0006] During the above igniting process, the generated axial striking force will be transferred
from the magnetic core 4 to the flanging 24 through the disc spring 21 and the cover
8 when the plunger 16 strikes the magnetic core 4. The flanging 24 has a relatively
small thickness, and thus will generate rearward and radially-outward elastic deformation.
In this case, the cover 8 will rapidly move in a rearward direction by a very small
distance. Then, the cover 8 gradually vibrates to go back its original position with
disappearance of the striking force. At the moment when the cover 8 backwardly moves
rapidly, the two contact posts 10 carried by it also backwardly move rapidly therewith,
but the contact bridge 14 can not completely follow up the backward moving action
of the contact posts 10. In this way, the contact bridge 14 may be disengaged from
the contact posts 10, which may cause momentary break of the main circuit of the electric
motor. The momentary break will cause momentary steep dropping of electric current
in the main circuit of the electric motor, affecting operation of the electric motor.
At the same time, electric arc can be generated between the contact bridge 14 and
the contact posts 10. It is proved by experiments that the maximum power of the electric
arc may reach 30 kilowatt and the produced energy may come to 8 Joule, and that energy
will cause ablation and adhesion between the contact bridge 14 and the contact posts
10.
[0007] EP 0 290 734 A2 discloses a solenoid switch sealed against water and dust for use in a vehicle starter
motor, comprising: a housing; a cover carrying a pair of contact posts, one end of
the cover being fixed to the housing; and a magnetic core fitted in a groove in the
inner wall of the housing opposite to the end of the cover.
[0008] Therefore, it is required to prevent the cover from moving during a pickup process
of the solenoid switch, so as to avoid failure of the solenoid switch due to adhesion
and avoid affecting operation of the electric motor.
Contents of the Invention
[0009] The present invention is intended to solve problems concerning the cover moving due
to the above striking in the known solenoid switch for the vehicle starter motor and
the caused ablation and adhesion between the contact bridge and the contact posts.
[0010] Therefor, the present invention in the first aspect provides a solenoid switch for
use in a vehicle starter motor, comprising: a housing; a cover carrying a pair of
contact posts, one end of the cover being fixed to the housing; and a magnetic core
fitted in the housing opposite to the end of the cover; wherein an engaging structure
between the magnetic core and the housing is independent of the cover such that a
force acting on the magnetic core in a direction toward the end of the cover can be
absorbed by the engaging structure.
[0011] According to preferred embodiments of the present invention, the housing has a segment
being adjacent to the end of the cover and having a relatively small wall thickness,
and the cover is retained in the housing by means of a flanging that is formed by
inward bending the segment having a relatively small wall thickness; and/or the solenoid
switch further comprises a plunger disposed in the housing and movable toward and
away from the magnetic core, and the force is a striking force generated by the plunger
striking the magnetic core during a working process of the solenoid switch.
[0012] According to preferred embodiments of the present invention, at least one portion
of a periphery of the magnetic core is fixed to the housing in a positive-fit locking
manner.
[0013] According to preferred embodiments of the present invention, an inner wall of the
housing is provided with a locking groove, the periphery of the magnetic core is provided
with a locking portion, and the locking portion is locked in the locking groove by
rotating the magnetic core so as to fix the magnetic core to the housing.
[0014] According to preferred embodiments of the present invention, the locking portion
abuts against a first side of the locking groove away from the end of the cover, and
an elastic element is provided between the locking portion and an opposite second
side of the locking groove; and/or the locking groove and/or the locking portion are
configured to gradually lock up the magnetic core with rotation of the magnetic core;
and/or the locking groove is defined by a step away from the end of the cover and
a plurality of limiting protrusions adjacent to the end of the cover, any two adjacent
limiting protrusions define a notch therebetween, the locking portion passes through
the notch in a direction away from the end of the cover and the locking portion and
the limiting protrusions are locked together by rotating the magnetic core.
[0015] According to preferred embodiments of the present invention, during an assembling
process, a locking groove for locking at least one part of the periphery of the magnetic
core is formed by inward pressing at least one part of the segment having a relatively
small wall thickness, so as to fix the 'magnetic core to the housing.
[0016] According to preferred embodiments of the present invention, an inward-protruding
limiting protrusion having a U-shaped cross section is formed by inward pressing the
segment having a relatively small wall thickness.
[0017] According to preferred embodiments of the present invention, the magnetic core is
fixed to the housing by welding; or a periphery of the magnetic core is provided with
a recess, and one part of the housing comes into the recess by pressing the housing
from the outside in a direction toward the recess during an assembling process, so
as to fix the magnetic core to the housing; or a periphery of the magnetic core is
provided with an external thread, an inner wall of the housing is provided with an
internal thread, and the magnetic core is fixed to the housing by means of toothed
engagement of the internal and external threads.
[0018] According to preferred embodiments of the present invention, the magnetic core is
fixed to the housing by a bolt that is screwed into a corresponding hole on a periphery
of the magnetic core through a wall of the housing; or the magnetic core is fixed
to the housing by a pin that enters a corresponding hole on a periphery of the magnetic
core through a through hole in a wall of the housing, and the pin is tightly fitted
into the through hole and/or the corresponding hole on the periphery.
[0019] The present invention in the second aspect provides a vehicle starter motor, comprising:
an electric motor; a transmission mechanism coupled to an output shaft of the electric
motor; and a solenoid switch for controlling operation of the electric motor and the
transmission mechanism, wherein the solenoid switch is a solenoid switch as claimed
above.
[0020] According to the solenoid switch of the present invention, when the plunger strikes
the magnetic core, the cover will not move axially since the magnetic core is directly
fixed to the housing and no striking force is transmitted to the housing, thereby
ensuring that no disengagement occurs between the contact bridge and the contact posts
and avoiding the momentary break of the main circuit of the electric motor. Thus,
it is possible to avoid momentary steep dropping of the electric current in the main
circuit of the known electric motor and avoid ablation and adhesion between the contact
bridge and the contact posts.
Description of the figures
[0021] Hereinafter the present invention is described in more details with reference to
the figures so as to better understand the principles, characteristics and advantages
of the invention.
Fig. 1 is a sectional view of a solenoid switch in a vehicle starter motor in the
prior art;
Fig. 2 is a schematic view of a fixing mode of a magnetic core in a rear end of a
housing of the solenoid switch in the prior art;
Figs. 3-7 are schematic views of several fixing modes of a magnetic core in a rear
end of a housing of a solenoid switch according to the present invention; and
Fig. 8 is a sectional view of one exemplary embodiment of the solenoid switch using
the fixing mode as shown in Fig. 3.
Detailed embodiments
[0022] Some embodiments of the present invention will be described hereinafter in more details
with reference to the figures to better understand the basic concept of the invention.
[0023] At first, it shall be noted that when describing the solenoid switch of the invention,
the word "front" indicating an orientation refers to a side close to a vehicle engine
in an axial direction, and the word "rear" refers to a side away from the vehicle
engine in the axial direction.
[0024] Fig. 2 shows a fixing mode of a magnetic core and a cover in a housing rear end of
a housing 2 of a solenoid switch in the prior art shown in Fig. 1, wherein the cover
8, a disc spring 21 and the magnetic core 4 are fixedly clamped between a step 22
and a rear flanging 24 of the housing 2 with a certain axial preloading force, and
the disc spring 21 is completely pressed axially between the cover 8 and the magnetic
core 4, without the capacity of making further axial deformation, i.e., without any
axial damping capacity. When the magnetic core 4 suffers from axial strike of a plunger
16, a striking force shown by an arrow in the figure is directly transferred to the
rear flanging 24 through the disc spring 21 and the cover 8, which causes relatively
great axial deformation of the rear flanging 24, making the cover to move axially.
Such axial moving will cause the various problems as mentioned in the above Background
Art portion.
[0025] The present invention aims to reduce or eliminate the axial moving of the cover by
changing the fixing mode of the magnetic core. Figs. 3-7 schematically show the fixing
modes of the magnetic core according to some exemplary embodiments of the invention.
[0026] In the embodiment shown in Fig. 3, an inner wall of the housing 2 is formed with
a plurality of limiting protrusions 26 located on the same circumference and extending
inward in the radial direction, and the plurality of limiting protrusions 26 are integrally
formed on an inner side of the housing 2 and spaced apart from each other in the circumferential
direction. That is, there is a notch between any two adjacent limiting protrusions
26. In order to show the notch more clearly, the left part of Fig. 3 schematically
shows one limiting protrusion 26, which is spaced apart from the right limiting protrusion
26.
[0027] According to one embodiment, the plurality of limiting protrusions 26 are evenly
distributed in the circumferential direction, so that the notches therebetween likewise
are evenly distributed in the circumferential direction.
[0028] The peripheral edge of the magnetic core 4 is provided with locking protrusions 30
having the same amount as the limiting protrusions 26 and corresponding to the limiting
protrusions 26 in position one by one, and the locking protrusions are sized and shaped
to enable the locking protrusions to pass through the notches in the axial direction.
When assembling, the locking protrusions 30 are axially aligned with the notches,
and then the magnetic core 4 is axially moved to cause the locking protrusions 30
to come into circumferential grooves 32 defined by the step 22 and the limiting protrusions
26. Subsequently, the magnetic core 4 is rotated by a certain angle to axially align
the locking protrusions 30 with the limiting protrusions 26, so that the magnetic
core 4 is fixed within the housing 2. Preferably, the shape of the locking protrusions
30 of the magnetic core 4 is adapted to the shape of the grooves 32, so that the magnetic
core 4 can hardly be locked within the grooves 32 in an axially movable manner. For
example, at least one of contacting surfaces of the locking protrusions 30 and limiting
protrusions 26 may be provided with a ramp that is gradually locked up with the rotation.
Such a fixing mode facilitates the installation.
[0029] At this moment, the cover 8 is fixedly clamped between the limiting protrusions 26
and the rear flanging 24. In this case, when the plunger 16 strikes the magnetic core
4, the generated axial striking force is transferred from the magnetic core 4 directly
to the housing 2 through the locking protrusions 30 and the limiting protrusions 26,
not to the rear flanging 24. In this way, it is possible to overcome moving of the
cover as in the prior art and the caused problems, i.e., momentary steep dropping
of the electric current in the main circuit of the electric motor, and the ablation
and adhesion problem between the contact bridge and the contact posts.
[0030] It can be appreciated that an elastic element 34 may be provided between the magnetic
core 4 and the limiting protrusions 26 in order to damp the striking effect of the
magnetic core 4 on the limiting protrusions 26, as shown in Fig. 4.
[0031] Actually, the fixing mode shown in Fig. 3 is involved with the positive-fit locking.
One skilled in the art completely can conceive any other appropriate positive-fit
locking modes. For example, Fig. 5 schematically shows another positive-fit locking
mode, wherein a limiting protrusion 36 for fixing the magnetic core 4 is formed by
pressing like the flanging 24. Specifically, during assembling process, after the
magnetic core 4 is fitted into the housing 2 and abuts with its side against the step
22, a thinning portion 38 of the housing 2 is inwardly pressed in the radial direction
to form the limiting protrusion 36, so as to clamp and fix the magnetic core 4 between
the step 22 and the limiting protrusion 36. At this moment, the limiting protrusion
36 is generally U-shaped and axially comprises two layers of thinning portion 38 so
as to be capable of bearing the striking force generated when the plunger 16 strikes
the magnetic core 4, without transmitting the striking force to the cover 8.
[0032] Fig. 6 schematically shows a fixing mode of the magnetic core according to another
exemplary embodiment of the present invention. As shown in Fig. 6, the magnetic core
4 is in contact with the step 22 at a first position 40 (the front end side) and with
the inner wall of the housing 2 at a second position 42 (the peripheral edge). The
magnetic core 4 is fixed to the housing 2 at the first position 40 and/or second position
42 by means of welding (such as electric resistance welding, friction welding, and
any other proper welding manner). The cover 8 still is fixedly clamped on to the housing
2 by the flanging 24. At this moment, the magnetic core 4 and the corresponding portions
of the housing 2 are welded together, and therefore the striking force generated when
the plunger 16 strikes the magnetic core 4 will be directly transmitted to the housing
2 by the welding portion, not to the cover 8 even if the magnetic core 4 and the cover
8 are in contact with one another.
[0033] Fig. 7 schematically shows a fixing mode of the magnetic core according to another
exemplary embodiment of the present invention. As shown in Fig. 7, the peripheral
edge of the magnetic core 4 is machined to form a recess 44. During the assembling
process, after the magnetic core 4 is fitted into the housing 2 and abuts with its
side against the step 22, a thinning portion 38 of the housing 2 is inwardly and radially
pressed toward the recess 44, and the thinning portion 38 is deformed, with one portion
coming into the recess 44, thereby fixing the magnetic core 4. The cover 8 still is
fixedly clamped on to the housing 2 by the rear flanging 24. At this moment, the striking
force generated when the plunger 16 strikes the magnetic core 4 also is directly transmitted
to the housing 2, not to the cover 8 even if the magnetic core 4 and the cover 8 are
in contact with one another.
[0034] For one skilled in the art, in addition to the above fixing modes, the magnetic core
4 also may be fixed to the housing 2 by screwing a bolt into the peripheral edge of
the magnetic core 4 from the outside. In this connection, a through hole through the
wall of the housing 2 and a corresponding hole on the peripheral edge of the magnetic
core 4 are provided, and both or one of the through hole through the wall of the housing
2 and the hole on the peripheral edge of the magnetic core 4 are a threaded hole.
It can be appreciated that the bolt can be replaced by a tightly-fitted pin. Here,
the striking force generated when the plunger 16 strikes the magnetic core 4 will
be directly transmitted to the housing 2 through the bolt or pin, not to the cover
8.
[0035] Furthermore, it can be considered that the inner circumference of the housing 2 is
provided with an internal thread, and the peripheral edge of the magnetic core 4 is
provided with a corresponding external thread, such that the magnetic core 4 can be
fixed to the housing 2 by screwing. Here, the striking force generated when the plunger
16 strikes the magnetic core 4 likewise will not be transferred to the cover 8.
[0036] A solenoid switch of a vehicle starter motor using the fixing mode as illustrated
in Fig. 3 is schematically described hereinafter.
[0037] As shown in Fig. 8, the solenoid switch comprises a housing 2 with a generally cylindrical
body 2a and a front end wall 2b disposed at a front end of the body (the left end
in Fig. 8, i.e., the end facing the side of the vehicle engine), and an axial through
hole is formed within the front end wall.
[0038] The magnetic core 4 is fixedly mounted in the rear part of the body 2a of the housing
2. The magnetic core 4 is comprised of a generally disc-shaped rear great-diameter
portion 4a, a generally cylindrical small-diameter portion 4b projecting forwardly
from the great-diameter portion, and a generally truncated cone portion 4c projecting
forwardly from the small-diameter portion. Formed on the periphery of the great-diameter
portion 4a is a set of discrete, preferably circular arc-shaped, locking protrusions
30, which project radially and outwards, and which are evenly distributed on the same
circumference and respectively extend by a radian in the circumferential direction.
Furthermore, formed within the magnetic core 4 is a guide through hole being axially
through in the front-back direction.
[0039] A generally cylindrical bushing 3 of a nonmagnetic material (such as brass) is mounted
in the housing 2, wherein a front end of the bushing 3 is inserted into the front
end wall 2b of the housing 2, and a rear end thereof is sleeved on the small-diameter
portion 4b of the magnetic core 4, so that the bushing 3 is fixed in the housing 2.
An electromagnetic winding 6 is mounted between the bushing 3 and the body of the
housing 2 and supported by the bushing 3.
[0040] In an approximately front part of the bushing 3, the plunger 16 is arranged in an
axially movable fashion. The plunger 16 is generally cylindrical.
[0041] A pull rod 18 is fastened to the front end of the plunger 16, wherein the rear end
of the pull rod extends forwardly from the front end of the plunger 16, while the
front end of the pull rod is used for operatively connecting an upper end of a shifting
fork (not shown). The approximately middle part of the shifting fork is pivotally
supported, and the lower end of the shifting fork is coupled to a transmission mechanism.
In this way, the pull rod 18 when moving backwardly in the axial direction (toward
the right in Fig. 8) can drive the transmission mechanism to move forwardly in the
axial direction through the shifting fork, such that a drive gear of the transmission
mechanism moves toward a gear ring on the engine flywheel and is engaged therewith.
Conversely, the pull rod 18 when moving forwardly in the axial direction (toward the
left in Fig. 8) can drive the transmission mechanism to move backwardly in the axial
direction through the shifting fork, such that the drive gear of the transmission
mechanism is disengaged from the gear ring on the engine flywheel.
[0042] A striking rod 20 is fixed in the approximately front part of the plunger 16. The
front part of the striking rod 20 can be inserted into the rear part of the pull rod
18 to assist in positioning and fixing of the pull rod 18 relative to the plunger
16. The middle part of the striking rod 20 is fixed in a corresponding part of the
striking rod 20. The rear part of the striking rod 20 extends into an axial receiving
through hole in the plunger 16.
[0043] Arranged within the receiving through hole of the plunger 16 and the guide through
hole of the magnetic core 4 is a switch shaft 12 that can axially move relative to
the plunger 16 and the magnetic core 4. A guide sleeve 13 around the periphery of
the switch shaft 12 can achieve guidance of the switch shaft 12 in the plunger 16
and in the magnetic core 4, and simultaneously assists in increasing a gap between
an inner peripheral wall of the guide through hole of the magnetic core 4 and an outer
peripheral surface of the switch shaft 12, so that a magnetic gap between the magnetic
core 4 and the switch shaft 12 is increased, thereby reducing influence of the switch
shaft 12 on a magnetic circuit generated by the electromagnetic winding 6.
[0044] A first reset spring 46, which is mounted between the front end of the switch shaft
12 and the front end of the magnetic core 4 (the generally truncated cone portion
4c), applies a forward force to the switch shaft 12 such that the switch shaft 12
is maintained at its most front original position under a non-operating condition
of the solenoid switch.
[0045] A second reset spring 48, which is mounted in the receiving through hole and between
the plunger 16 and the front end of the switch shaft 12, applies a forward force to
the plunger 16 such that the plunger 16 is maintained at its most front original position
under the non-operating condition of the solenoid switch.
[0046] The front part of the switch shaft 12 is located within the receiving through hole
of the plunger 16, the middle part of the switch shaft 12 passes through the guide
through hole of the magnetic core 4, and the rear end of the switch shaft 12 is exposed
from the rear end surface of the magnetic core 4.
[0047] A contact bridge 14 is mounted on the rear end of the switch shaft 12. Specifically,
a mounting base 15 is mounted on the rear part of the switch shaft 12 in an axially
slideable manner, and the contact bridge 14 is carried by the mounting base 15.
[0048] Furthermore, a third reset spring 50 is sleeved on the switch shaft 12 and located
between the rear end of the guide sleeve 13 and the mounting base 15. The contact
bridge 14 carried by the mounting base 15 can resist a pushing force of the third
reset spring 50 to move (slide) axially and forwardly on the switch shaft 12, while
the backward movement of the contact bridge 14 is blocked by a fastener 17 fixed on
the rear end of the switch shaft 12.
[0049] The cover 8, which is normally made of a plastic material, is fixed at a rear part
of the housing 2, and the two contact posts 10 extend through the cover 8 and fixed
in the cover 8. A front enlarging portion of each of the contact posts 10 forms into
a contact terminal 10a, and front end surfaces of the two contact terminals 10a face
rear surface of the contact bridge 14. A front part of each of the contact posts 10
is fixed in the cover 8, and a rear part thereof is exposed from a rear surface of
the cover 8 so as to form a connection terminal.
[0050] The cover 8 has a front end 8a that is fitted in the housing 2. As shown in Fig.
8, the rear end (the great-diameter portion 4a) of the magnetic core 4 and the front
end 8a of the cover 8 are retained in the rear end portion of the housing 2 by using
the fixing mode shown in Fig. 3. Therefore, as shown in Fig. 8, integrally formed
on the rear end of the generally cylindrical body 2a of the housing 2 are a step 22
and a plurality of discrete limiting protrusions 26 that extend radially and inwards
and are located on the same circumference, and circumferential grooves 32 are defined
between the step 22 and the limiting protrusions 26. The limiting protrusions 26 are
the same in the amount as the locking protrusions 30. A thinning portion 2c is formed
behind the limiting protrusion 26, and the wall thickness of the thinning portion
2c is reduced in comparison to the body 2a.
[0051] The limiting protrusions 26 preferably are evenly spaced apart from each other in
the circumferential direction. The locking protrusions 30 correspond, one by one,
to the notches between the limiting protrusions 26 (also to the limiting protrusions
26), and are sized and shaped to axially pass through the notches and be mounted within
the grooves 32.
[0052] During the assembling, the magnetic core 4 is placed into the housing 2 from the
rear end of the housing 2 in such a way that its truncated cone portion 4c faces the
front, and the locking protrusions 30 are aligned with the notches, and then the magnetic
core 4 is axially displaced to cause the locking protrusions 30 into the grooves 32.
Subsequently, the magnetic core 4 is rotated by a certain angle so as to cause the
locking protrusions 30 aligned with and locked with the limiting protrusions 26, thereby
fixing the magnetic core 4 within the housing.
[0053] The rear end of the thinning portion 2c is adapted to form a rear flanging 24 that
extends radially and inwards after the magnetic core 4 and the cover 8 are placed
into the housing 2. Thus, it can be understood that although Fig. 8 already draws
the rear flanging 24, it actually is formed during the assembling process of the solenoid
switch.
[0054] During the working process, when the plunger 16 strikes the magnetic core 4, the
generated axial striking force will be transferred from the magnetic core 4 directly
to the housing 2 through the limiting protrusions 26, not to the rear flanging 24.
[0055] It can be understood that in the solenoid switch shown in Fig. 8 the magnetic core
also can employ the other above-mentioned fixing modes of the present invention, as
an alternative solution.
[0056] It was proved by the simulation and experiments that according to the prior art solenoid
switch, the cover obviously will move in the axial direction when the plunger strikes
the magnetic core, which may result in disengagement between the contact bridge and
the contact posts so as to cause the momentary break of the main circuit of the electric
motor. Such momentary break will cause momentary steep dropping of the electric current
in the main circuit of the electric motor, affecting the operation of the electric
motor. At the same time, electric arc may be generated between the contact bridge
and the contact posts, causing the ablation and adhesion between the contact bridge
and the contact posts.
[0057] On the contrary, according to the present invention, when the plunger strikes the
magnetic core, the striking force will not be transferred to the cover since the magnetic
core is directly secured to the housing. The cover thus will not move axially so as
to avoid the disengagement between the contact bridge and the contact posts, without
causing the momentary break of the main circuit of the electric motor. Therefore,
it is possible to overcome the problem concerning the momentary steep dropping of
the electric current in the main circuit of the electric motor in the prior art, as
well as the ablation and adhesion problem between the contact bridge and the contact
posts.
[0058] Other aspects of the present invention relate to a vehicle starter motor comprising
such a solenoid switch.
1. A solenoid switch for use in a vehicle starter motor, comprising:
a) a housing (2);
b) a cover (8) carrying a pair of contact posts (10), one end of the cover (8) being
fixed to the housing (2); and
c) a magnetic core (4) fitted in the housing (2) opposite to the end of the cover
(8);
d) wherein an engaging structure between the magnetic core (4) and the housing (2)
is independent of the cover (8) such that a force acting on the magnetic core (4)
in a direction toward the end of the cover (8) can be absorbed by the engaging structure,
wherein
e) an inner wall of the housing (8) is provided with a locking groove (32), the periphery
of the magnetic core (4) is provided with a locking portion (30), and the locking
portion (30) is locked in the locking groove by rotating the magnetic core so as to
fix the magnetic core to the housing; and
f) the locking portion (30) abuts against a first side of the locking groove (32)
away from the end of the cover (8), and an elastic element (34) is provided between
the locking portion (30) and an opposite second side of the locking groove (32).
2. A solenoid switch as claimed in claim 1, characterized in that
the housing (2) has a segment being adjacent to the end of the cover and having a
relatively small wall thickness, and the cover (8) is retained in the housing (2)
by means of a flanging (24) that is formed by inward bending the segment having a
relatively small wall thickness.
3. A solenoid switch as claimed in claim 1 or 2, characterized in that
the solenoid switch further comprises a plunger (16) disposed in the housing (2) and
movable toward and away from the magnetic core (4), and the force is a striking force
generated by the plunger (16) striking the magnetic core (4) during a working process
of the solenoid switch.
4. A solenoid switch as claimed in claim 1 or 2, characterized in that at least one portion of a periphery of the magnetic core is (4) fixed to the housing
(2) in a positive-fit locking manner.
5. A solenoid switch as claimed in claim 1, characterized in that
the locking groove (32) and the locking portion (30) are configured to gradually lock
up the magnetic core (4) with rotation of the magnetic core (4).
6. A solenoid switch as claimed in claim 1 or 5, characterized in that the locking groove (32) is defined by a step (22) away from the end of the cover
(8) and a plurality of limiting protrusions (26) adjacent to the end of the cover
(8), any two adjacent limiting protrusions (26) define a notch therebetween, the locking
portion (30) passes through the notch in a direction away from the end of the cover
(8) and the locking portion (30) and the limiting protrusions (26) are locked together
by rotating the magnetic core.
7. A solenoid switch as claimed in claim 4 or 1, characterized in that during an assembling process, a locking groove (32) for locking at least one part
of the periphery of the magnetic core (4) is formed by inward pressing at least one
part of the segment having a relatively small wall thickness, so as to fix the magnetic
core (4) to the housing (2).
8. A solenoid switch as claimed in claim 7, characterized in that
an inward-protruding limiting protrusion (26) having a U-shaped cross section is formed
by inward pressing the segment having a relatively small wall thickness.
9. A solenoid switch as claimed in claim 1 or 2, characterized in that the magnetic core is fixed to the housing by welding.
10. A solenoid switch as claimed in claim 1 or 2, characterized in that a periphery of the magnetic core (4) is provided with a recess, and one part of the
housing comes into the recess (44) by pressing the housing (2) from the outside in
a direction toward the recess (44) during an assembling process, so as to fix the
magnetic core (4) to the housing (2).
11. A solenoid switch as claimed in claim 1 or 2, characterized in that a periphery of the magnetic core (4) is provided with an external thread, an inner
wall of the housing (2) is provided with an internal thread, and the magnetic core
(4) is fixed to the housing (2) by means of toothed engagement of the internal and
external threads.
12. A solenoid switch as claimed in claim 1 or 2, characterized in that
the magnetic core is (4) fixed to the housing (2) by a bolt that is screwed into a
corresponding hole on a periphery of the magnetic core (4) through a wall of the housing
(2).
13. A solenoid switch as claimed in claim 1 or 2, characterized in that
the magnetic core (4) is fixed to the housing (2) by a pin that enters a corresponding
hole on a periphery of the magnetic core (4) through a through hole in a wall of the
housing (2), and the pin is tightly fitted into the through hole and/or the corresponding
hole on the periphery.
14. A vehicle starter motor, comprising:
i) an electric motor;
ii) a transmission mechanism coupled to an output shaft of the electric motor; and
iii) a solenoid switch for controlling operation of the electric motor and the transmission
mechanism;
iv) wherein the solenoid switch is a solenoid switch as claimed in any one of claims
1-13.
1. Magnetschalter zur Verwendung in einem Fahrzeugstartermotor, der Folgendes umfasst:
a) ein Gehäuse (2);
b) ein Abdeckung (8), die ein Paar Kontaktsäulen (10) trägt, wobei ein Ende der Abdeckung
(8) am Gehäuse (2) befestigt ist; und
c) einen Magnetkern (4), der gegenüber dem Ende der Abdeckung (8) in das Gehäuse (2)
eingepasst ist;
d) wobei eine Eingriffstruktur zwischen dem Magnetkern (4) und dem Gehäuse (2) unabhängig
von der Abdeckung (8) ist, derart, dass eine Kraft, die in einer Richtung zum Ende
der Abdeckung (8) auf den Magnetkern (4) wirkt, durch die Eingriffstruktur absorbiert
werden kann, wobei
e) eine Innenwand des Gehäuses (8) mit einer Verriegelungsfuge (32) versehen ist,
der Umfang des Magnetkerns (4) mit einem Verriegelungsabschnitt (30) versehen ist
und der Verriegelungsabschnitt (30) durch Drehen des Magnetkerns in der Verriegelungsfuge
verriegelt wird, um den Magnetkern am Gehäuse zu befestigen; und
f) der Verriegelungsabschnitt (30) gegen eine vom Ende der Abdeckung (8) entfernte,
erste Seite der Verriegelungsfuge (32) stößt und ein elastisches Element (34) zwischen
dem Verriegelungsabschnitt (30) und einer gegenüberliegenden zweiten Seite der Verriegelungsfuge
(32) vorgesehen ist.
2. Magnetschalter nach Anspruch 1, dadurch gekennzeichnet, dass
das Gehäuse (2) ein Segment aufweist, das an das Ende der Abdeckung angrenzt und eine
relativ kleine Wanddicke aufweist und die Abdeckung (8) mittels einer Bördelung (24)
im Gehäuse (2) gehalten wird, die durch Biegen des Segments, das eine relativ kleine
Wanddicke aufweist, nach innen gebildet ist.
3. Magnetschalter nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass
der Magnetschalter ferner einen Kolben (16) umfasst, der im Gehäuse (2) angeordnet
und zum Magnetkern hin und davon weg beweglich ist, und die Kraft eine Aufprallkraft
ist, die erzeugt wird, indem der Kolben (16) während eines Arbeitsvorgangs des Magnetschalters
auf den Magnetkern (4) schlägt.
4. Magnetschalter nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass
mindestens ein Abschnitt eines Umfangs des Magnetkerns (4) auf eine formschlüssig
verriegelnde Weise am Gehäuse (2) befestigt ist.
5. Magnetschalter nach Anspruch 1, dadurch gekennzeichnet, dass
die Verriegelungsfuge (32) und der Verriegelungsabschnitt (30) konfiguriert sind,
den Magnetkern (4) mit der Drehung des Magnetkerns (4) allmählich zu verriegeln.
6. Magnetschalter nach Anspruch 1 oder 5, dadurch gekennzeichnet, dass
die Verriegelungsfuge (32) durch eine vom Ende der Abdeckung (8) entfernte Stufe (22)
und mehrere an das Ende der Abdeckung (8) angrenzende, begrenzende Vorsprünge (26)definiert
ist, wobei jeweils zwei benachbarte begrenzende Vorsprünge (26) dazwischen eine Kerbe
definieren, der Verriegelungsabschnitt (30) in einer Richtung vom Ende der Abdeckung
(8) weg durch die Kerbe verläuft und der Verriegelungsabschnitt (30) und die begrenzenden
Vorsprünge (26) durch Drehen des Magnetkerns miteinander verriegelt werden.
7. Magnetschalter nach Anspruch 4 oder 1, dadurch gekennzeichnet, dass
während eines Montagevorgangs eine Verriegelungsfuge (32) zum Verriegeln zumindest
eines Teils des Umfangs des Magnetkerns (4) durch Drücken zumindest eines Teils des
Segments, das eine relativ kleine Wanddicke aufweist, nach innen gebildet wird, um
den Magnetkern (4) am Gehäuse (2) zu befestigen.
8. Magnetschalter nach Anspruch 7, dadurch gekennzeichnet, dass
ein nach innen vorstehender, begrenzender Vorsprung (26), der einen U-förmigen Querschnitt
aufweist, durch Drücken des Segments, das eine relativ kleine Wanddicke aufweist,
nach innen gebildet ist.
9. Magnetschalter nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass
der Magnetkern durch Schweißen am Gehäuse befestigt ist.
10. Magnetschalter nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass
ein Umfang des Magnetkerns (4) mit einer Vertiefung versehen ist und eine Komponente
des Gehäuses durch Drücken des Gehäuses (2) von außen in einer Richtung zur Vertiefung
(44) während eines Montagevorgangs in die Vertiefung (44) gelangt, um den Magnetkern
(4) am Gehäuse (2) zu befestigen.
11. Magnetschalter nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass
ein Umfang des Magnetkerns (4) mit einem Außengewinde versehen ist, eine Innenwand
des Gehäuses (2) mit einem Innengewinde versehen ist und der Magnetkern (4) mittels
des verzahnten Eingriffs des Innengewindes und des Außengewindes am Gehäuse (2) befestigt
ist.
12. Magnetschalter nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass
der Magnetkern (4) durch einen Bolzen am Gehäuse (2) befestigt ist, der durch eine
Wand des Gehäuses (2) in ein entsprechendes Loch auf einem Umfang des Magnetkerns
(4) geschraubt ist.
13. Magnetschalter nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass
der Magnetkern (4) durch einen Stift am Gehäuse (2) befestigt ist, der durch ein Durchgangsloch
in einer Wand des Gehäuses (2) in ein entsprechendes Loch in einem Umfang des Magnetkerns
(4) eintritt, und dass der Stift in das Durchgangsloch und/oder das entsprechende
Loch in dem Umfang fest eingepasst ist.
14. Fahrzeugstartermotor, der Folgendes umfasst:
i) einen Elektromotor;
ii)einen Getriebemechanismus, der mit einer Ausgangswelle des Elektromotors gekoppelt
ist; und
iii) einen Magnetschalter zum Steuern des Betriebs des Elektromotors und des Getriebemechanismus;
iv)wobei der Magnetschalter ein Magnetschalter nach einem der Ansprüche 1-13 ist.
1. Commutateur électromagnétique destiné à être utilisé dans un moteur de démarrage de
véhicule, comprenant :
a) un boîtier (2) ;
b) un couvercle (8) portant une paire de ports de contact (10), une extrémité de ce
couvercle (8) étant fixée au boîtier (2) ; et
c) un noyau magnétique (4) monté dans le boîtier (2) en face de l'extrémité du couvercle
(8) ;
d) dans lequel une structure d'engagement entre le noyau magnétique (4) et le boîtier
(2) est indépendante du couvercle (8) de manière à ce qu'une force agissant sur le
noyau magnétique (4) dans une direction vers l'extrémité du couvercle (8) puisse être
absorbée par la structure d'engagement, dans lequel
e) une paroi interne du boîtier (8) est pourvue d'une rainure de blocage (32), le
pourtour du noyau magnétique (4) est pourvu d'une partie de blocage (30), et cette
partie de blocage (30) est bloquée dans la rainure de blocage en tournant le noyau
magnétique de façon à fixer le noyau magnétique au boîtier ; et
f) la partie de blocage (30) bute contre un premier côté de la rainure de blocage
(32) écarté de l'extrémité du couvercle (8), et un élément élastique (34) est prévu
entre la partie de blocage (30) et un deuxième côté opposé de la rainure de blocage
(32).
2. Commutateur électromagnétique selon la revendication 1, caractérisé en ce que
le boîtier (2) a un segment étant adjacent à l'extrémité du couvercle et ayant une
épaisseur de paroi relativement petite, et le couvercle (8) est maintenu dans le boîtier
(2) au moyen d'un rabattage (24) qui est formé en courbant vers l'intérieur le segment
ayant une épaisseur de paroi relativement petite.
3. Commutateur électromagnétique selon la revendication 1 ou 2, caractérisé en ce que
ce commutateur électromagnétique comprend un plongeur (16) disposé dans le boîtier
(2) et pouvant être bougé vers le noyau magnétique (4) et à l'écart de celui-ci, et
la force est une force de frappe produite par le plongeur (16) qui heurte le noyau
magnétique (4) pendant un processus de travail du commutateur électromagnétique.
4. Commutateur électromagnétique selon la revendication 1 ou 2, caractérisé en ce que
au moins une partie d'un pourtour du noyau magnétique (4) est fixée au boîtier (2)
d'une manière de blocage à ajustement positif.
5. Commutateur électromagnétique selon la revendication 1, caractérisé en ce que
la rainure de blocage (32) et la partie de blocage (30) sont configurées de façon
à bloquer progressivement le noyau magnétique (4) avec la rotation du noyau magnétique
(4).
6. Commutateur électromagnétique selon la revendication 1 ou 5, caractérisé en ce que la rainure de blocage (32) est définie par un gradin (22) s'écartant de l'extrémité
du couvercle (8) et une pluralité de saillies de limitation (26) adjacentes à l'extrémité
du couvercle (8), n'importe quelles deux saillies de limitation (26) définissent une
encoche entre elles, la partie de blocage (30) passe à travers cette encoche dans
une direction s'écartant de l'extrémité du couvercle (8) et la partie de blocage (30)
et les saillies de limitation (26) sont bloquées ensemble en tournant le noyau magnétique.
7. Commutateur électromagnétique selon la revendication 4 ou 1, caractérisé en ce que
pendant le processus d'assemblage, une rainure de blocage (32) pour bloquer au moins
une partie du pourtour du noyau magnétique (4) est formée en pressant vers l'intérieur
au moins une partie du segment ayant une épaisseur de paroi relativement petite, de
manière à fixer le noyau magnétique (4) au boîtier (2).
8. Commutateur électromagnétique selon la revendication 7, caractérisé en ce que
une saillie de limitation faisant saillie vers l'intérieur (26) ayant une section
transversale en forme de U est formée en pressant vers l'intérieur le segment ayant
une épaisseur de paroi relativement petite.
9. Commutateur électromagnétique selon la revendication 1 ou 2, caractérisé en ce que
le noyau magnétique est fixé au boîtier par soudage.
10. Commutateur électromagnétique selon la revendication 1 ou 2, caractérisé en ce que
un pourtour du noyau magnétique (4) est pourvu d'un évidement, et une partie du boîtier
pénètre dans cet évidement (44) en pressant le boîtier (2) depuis l'extérieur dans
une direction vers l'évidement (44) pendant un processus d'assemblage, de manière
à fixer le noyau magnétique (4) au boîtier (2).
11. Commutateur électromagnétique selon la revendication 1 ou 2, caractérisé en ce que
un pourtour du noyau magnétique (4) est pourvu d'un filet externe, une paroi interne
du boîtier (2) est pourvue d'un filet interne, et le noyau magnétique (4) est fixé
au boîtier (2) au moyen d'un engagement denté des filets interne et externe.
12. Commutateur électromagnétique selon la revendication 1 ou 2, caractérisé en ce que
le noyau magnétique (4) est fixé au boîtier (2) par un boulon qui est vissé dans un
trou correspondant sur un pourtour du noyau magnétique (4) à travers une paroi du
boîtier (2).
13. Commutateur électromagnétique selon la revendication 1 ou 2, caractérisé en ce que
le noyau magnétique (4) est fixé au boîtier (2) par une goupille qui pénètre dans
un trou correspondant sur un pourtour du noyau magnétique (4) à travers un trou débouchant
dans une paroi du boîtier (2), et cette goupille est montée avec un ajustement serré
dans le trou débouchant et/ou le trou correspondant sur le pourtour.
14. Moteur de démarrage d'un véhicule, comprenant :
i) un moteur électrique ;
ii) un mécanisme de transmission accouplé à un arbre de sortie du moteur électrique
; et
iii) un commutateur électromagnétique pour commander le fonctionnement du moteur électrique
et du mécanisme de transmission ;
iv) dans lequel le commutateur électromagnétique est un commutateur électromagnétique
selon l'une quelconque des revendications 1 à 13.