JPH08291782A - One way clutch - Google Patents

Abstract

PURPOSE: To prevent breakage of an elastic body which is caused that the elastic body gets out its attitude. CONSTITUTION: An over running clutch 6 is provided with a cylindrical part 554 having a housing groove 555 and a plurality of wedge shaped grooves 556 whose diameter direction clearance is enlarged in a circumferential direction, a roller 61 which is housed in the wedge shaped grooves 556, and a plurality of recessed parts 341 for locking the roller 61. It is also provided with a small diameter cylindrical part 34 arranged coaxially on the cylindrical part 554, a coil spring 62 housed in the housing groove 555, a projection piece 631 which is faced to the housing groove 555 and energized by the coil spring 62, and a projection piece 632 which is faced to the wedge shaped grooves 556 and for push-pressing the roller 61 in a groove narrow direction. It is further provided with a ring body 63 which is rotatably assembled on the circular groove of the cylindrical part 554.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-way clutch used in a starter for starting an engine.

[0002]

2. Description of the Related Art A general one-way clutch 100, as shown in FIG. 8, has a cylindrical outer 102 having a plurality of wedge-shaped grooves 101 and a rolling element 1 housed in each wedge-shaped groove 101.
03 and inner 108 arranged coaxially with the outer 102.
And an elastic body 106 that is housed in the wedge-shaped groove 101 and biases the rolling element 103 in the groove narrowing direction, and causes the rolling element 103 to bite into the groove narrowly and to provide friction according to the Hertz stress generated on the contact surface. Torque is transmitted by force.

Further, as another one-way clutch, Japanese Utility Model Publication No. 59-26107 discloses that a wedge-shaped space is appropriately angled, and a locking portion projecting from a driving body is arranged to engage with the wedge space. Disclosed is a one-way clutch having a protective device that absorbs impact torque by abutting a roller and keeping the amount of biting constant (the torque is transmitted at a constant torque).

[0004] However, the above-mentioned Jitsuko Sho 59-26
In the one-way clutch described in Japanese Patent Laid-Open No. 107, the locking portion needs to be set at a predetermined position in order to make the amount of bite constant, but the inner peripheral surface of the wedge-shaped space of the clutch outer and the outer peripheral surface of the clutch inner. The abutting surface of the roller in contact with and is greatly swung to the left and right due to the slight inclination of the wedge-shaped space, and the position cannot be accurately set. As a result, there is a problem that the maximum value of the transmission torque cannot be accurately determined and the impact torque is not sufficiently absorbed.

[0005]

Therefore, the present inventors have
In order to solve this inconvenience, we applied for a one-way clutch having the following structure (Japanese Patent Application No. 6-213707). As shown in FIG. 7, the one-way clutch 200 includes a cylindrical outer 202 having a plurality of wedge-shaped grooves 201, and each wedge-shaped groove 2.
01, which has a rolling element 203 housed in 01 and a plurality of arcuate recesses 204 that lock the rolling element 203, and is coaxially arranged on the outer 202; and a rolling element 203 housed in the wedge-shaped groove 201. And an elastic body 206 for urging the blades in the narrow groove direction. This one-way clutch 200 is, as shown in FIG. 1 of the specification of Japanese Patent Application No. 6-213707,
It is attached to the planetary gear reduction mechanism shown below.

The planetary gear reduction mechanism has a sun gear formed on the armature shaft of the starter motor, a planetary gear that meshes with the sun gear, and an internal gear that meshes with the planetary gear. A part of the internal gear extends in the axial direction to form the inner 205.

The operation of the starter employing the one-way clutch 200 will be briefly described. When starting the engine, the armature shaft of the starter motor rotates,
Further, the planet gears rotate via the sun gear, and the planet gears rotate the internal gear (inner 205). At this time, the rolling element 203 moves in the groove narrowing direction by the friction and the elastic element 206 and fits into the arcuate concave portion 204, and the internal gear (inner 205) is locked by the outer 202 and is axially supported by the bearing 209. The drive shaft 207 rotates.

The one-way clutch 200 includes an inner 205.
With the arcuate recessed portion 204, the transmission angle θ {outer 202
To the inner 205} can be set large, and as a result, the transfer function for the same torque becomes small, so that the clutch can be made small and lightweight.

However, the present inventors have found the following problems with this one-way clutch 200. In the one-way clutch 200, the elastic body 206 has the rolling element 203.
Since it is pressed and moved to the arcuate recessed portion 204, the stroke S of the rolling element 203 becomes longer than that of the clutch 100 having the inner circle 108 without the arcuate recessed portion shown in FIG. Therefore, the elastic body 206 is in an abnormal posture and is easily damaged.
It will not be fixed to and the engine will not start. When the elastic body 206 is a coil spring,
Tilting or bending occurs, and the arcuate concave portion 204 and the wedge-shaped groove 201 are formed.
There is a problem that the coil spring is caught in the wide groove portion of the above.

Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a one-way clutch which prevents damage to an elastic body due to tilting of the posture of the elastic body.

[0011]

The one-way clutch of the present invention employs the following technical means. [Means for Claim 1] A cylindrical outer member having a housing groove and a plurality of wedge-shaped grooves whose radial intervals increase as it rotates in the circumferential direction, a rolling element housed in the wedge-shaped groove, and the rolling element. A first cylindrical inner member having a plurality of recesses for locking, which is loosely fitted to the outer, an elastic body housed in the housing groove, and a first body urged by the elastic body facing the housing groove. And a ring body that has a protruding piece and a second protruding piece that faces the wedge-shaped groove and presses the rolling element in the groove narrowing direction, and is rotatably assembled to the outer side.

[Means for Claim 2] In the one-way clutch according to claim 1, the storage groove is formed on an axial side surface of the outer, the ring body is disc-shaped, and The elastic body is held between the end surface and the outer.

[Means for Claim 3] In the one-way clutch according to claim 1, the housing groove is formed on the inner periphery of the outer, the ring body is cylindrical, and the outer periphery of the ring body is cylindrical. Holds the elastic body.

[Means of Claim 4] Claims 1 to 3
In the one-way clutch described above, the number of the elastic bodies accommodated in the accommodation groove is smaller than the number of the rolling elements accommodated in the wedge-shaped groove.

[Means of Claim 5] Claims 1 to 4
In the described one-way clutch, the elastic body is a coil spring.

[0016]

[Action]

[Claim 1] When a rotational driving force is applied to the outer, the elastic body urges the first projecting piece to rotate the ring body, and the second projecting piece presses the rolling element into a recess. Moves in the narrow direction of the wedge-shaped groove while being fitted into the portion (in the case of a structure in which the inner is fixed). As a result, the rolling element bites between the outer and inner parts, and the outer is prevented from rotating by the inner part, so that the one-way clutch transmits the rotational driving force applied to the outer part.

When a rotational driving force in the opposite direction is applied to the outer, the rolling element comes out of the recess and moves in the wide direction of the wedge-shaped groove to urge the second projecting piece to rotate the ring body. Then, the first protruding piece compresses the elastic body. As a result, the outer rotates idly in the opposite direction, and the one-way clutch cuts off the reverse rotational driving force applied to the outer.

Since the elastic body is housed in the outer storage groove and surrounded by the groove wall and does not come into direct contact with the rolling element, the posture is not disturbed at the time of torque transmission or torque cutoff. Elastically deforms.

[Claim 2] The elastic body is housed in the outer housing groove and is surrounded by the groove wall and the end surface of the ring body, and is not in direct contact with the rolling element. When transmitting or shutting off torque, it elastically deforms without losing its posture.

[Claim 3] The elastic body is housed in the outer housing groove and surrounded by the groove wall and the cylindrical outer peripheral wall of the ring body, and is not in direct contact with the rolling element. When transmitting or shutting off torque, it elastically deforms without losing its posture.

[Claim 4] Since the first and second projecting pieces are integral with the ring body, the elastic body accommodated in the storage groove by having a plurality of rolling elements supported by one elastic body. Can be less than the number of wedge-shaped grooves.

[Claim 5] When the coil spring is used as the elastic body and the rolling element is directly pressed by the coil spring (the one-way clutch 200), the coil spring is prevented from falling or bending due to interference with the inner. As a result, the coil spring is caught in the arc-shaped recess, the wide groove portion of the wedge-shaped groove, or the like.

However, the one-way clutch of the present invention is
Being stored in the outer storage groove and surrounded by the groove wall (or the groove wall and the cylindrical outer peripheral wall of the ring body),
By not contacting the rolling elements, the coil spring does not fall or bend during torque transmission or torque interruption, and the coil spring can be prevented from being caught.

[0024]

【The invention's effect】

[Claim 1] The elastic body is accommodated in the outer storage groove and surrounded by a groove wall, and is not in direct contact with the rolling element. Elastically deforms without breaking. Therefore, it is possible to prevent the elastic body from being damaged due to the posture collapse of the elastic body.

Since the first and second projecting pieces are integral with the ring body, when the rotational driving force is applied to the outer, the second projecting piece presses the rolling elements at the same time, and all the rolling elements are simultaneously pressed. It can be moved into the narrow groove. Therefore, the one-way clutch can quickly transmit the rotational driving force applied to the outer.

[Claim 2] Since the elastic body is housed in the outer housing groove and is surrounded by the groove wall and the end surface of the ring body, and is not in direct contact with the rolling element, the torque When transmitting or shutting off torque, it elastically deforms without losing its posture. Therefore, it is possible to prevent the elastic body from being damaged due to the posture collapse of the elastic body.

[Claim 3] The elastic body is housed in the outer housing groove and surrounded by the groove wall and the cylindrical outer peripheral wall of the ring body, and is not in direct contact with the rolling element. , When the torque is transmitted or cut off, it is elastically deformed without losing its posture. Therefore, it is possible to prevent the elastic body from being damaged due to the posture collapse of the elastic body. Further, the formation of the storage groove and the assembling of the one-way clutch can be easily performed.

[Claim 4] Since it is not necessary to press each rolling element with the elastic body, the number of elastic bodies can be made smaller than the number of rolling elements. Thereby, the number of parts (elastic body) can be reduced. On the contrary, since the rolling element space in the wedge-shaped groove is not necessary and the number of housing grooves is smaller than the number of rolling elements, the number of wedge-shaped grooves and the number of rolling elements are increased to improve the torque transmission characteristic. You can also

[Claim 5] Even if a coil spring is adopted as the elastic body (having excellent durability), the coil spring does not interfere with the inner and the coil spring does not fall or bend.
It is possible to improve durability without trouble.

[0030]

The first embodiment of the present invention (claims 1, 2, 4, 5)
The starter 1000 with a planetary gear speed reduction mechanism according to the present invention will be described with reference to FIGS. In FIG. 1, 1 is a starter housing, 2 is a starter motor, 3 is a center case, 4 is a magnet switch, 5 is a planetary gear reduction mechanism, 6 is an overrunning clutch, 7 is a drive shaft, and 8 is a ring gear on the engine side. is there.

The starter motor (DC motor) 2 is mounted on the right side of the housing 1 in the figure, and is provided with a yoke 21, a field coil, an armature, a brush, and the like. When the engine is started, the crankshaft is rotated at a speed equal to or higher than the minimum starting speed. Generates a torque to drive.

The rear end (right end in the figure) of the armature shaft 22 that rotates integrally with the armature has the end bracket 2.
The small diameter portion 221 at the front end (the left side in the drawing) is fixed by a bearing 71 arranged in the base end recess of the drive shaft 7. The front end of the armature shaft 22 has a large diameter portion 222 having a sun gear 51 formed on the outer periphery,
The small diameter portion 221 extends forward from the large diameter portion 222.

The drive shaft 7 extends along the same axis as the armature shaft 22 and has a front end (the left end in the drawing).
Is supported by a bearing 11 arranged in the housing 1, and the vicinity of the rear end is supported by a bearing 31 arranged in the center case 3,
The rear end (right end in the drawing) is a flange-shaped large-diameter portion 70 having a plurality of through holes 701.

A pin 702 is press-fitted into each through hole 701, and a protruding portion of the pin 702 rotatably supports the planet gear 54 via a bearing 703. These planetary gears 5
No. 4 meshes with the sun gear 51 on the small diameter side, and meshes with the internal teeth 551 of the internal gear 55 on the large diameter side.

The internal gear 55 has a substantially cylindrical shape with openings on both sides, and has a large diameter cylindrical portion 552 having inner teeth 551 formed on the inner peripheral surface thereof, and an end wall extending radially inward from the left end of the large diameter cylindrical portion 552. It has a portion 553 and a cylindrical portion 554 that extends in the axial direction from the inner wall of the end wall portion 553. The planetary gear 54, the sun gear 51, and the internal gear 55 constitute the planetary gear reduction mechanism 5.

A helical spline groove 73 is formed on the outer periphery of the center of the drive shaft 7, and a spline tube 72 having a pinion gear 721 at its tip is spline-fitted into the helical spline groove 73.

A shift lever 41 for pushing the spline tube 72 forward is pivotally supported by the support portion 12 provided in the housing 1. The lower portion of the shift lever 41 abuts on the rear portion of the spline tube 72, and the upper portion of the shift lever 41 is hooked to the plunger of the magnet switch 4.
It is connected to.

The center case 3 (cylindrical with a bottom), the outer periphery of which is fixed to the housing 1 while being sandwiched between the yoke 21 and the housing 1 in the axial direction, has a large diameter cylindrical portion 32 and a left end of the large diameter cylindrical portion 32. From the inner wall of the end wall 33, and a small-diameter cylindrical portion 34 extending axially from the inner wall of the end wall 33, and accommodates the planetary gear reduction mechanism 5 described above.

Next, the overrunning clutch 6 is shown in FIG.
~ It demonstrates based on FIG. In addition, FIG. 2 is an M view of FIG.
3 is a sectional view taken along the line iii-iii, and FIG. 4 is a sectional view taken along the line iv-iv.

The overrunning clutch 6 includes a cylindrical portion 554 (outer) of the internal gear 55, a cylindrical roller 61, a small diameter cylindrical portion 34 (inner) of the center case 3, a coil spring 62, and a ring body 63. Composed of and.

The cylindrical portion 554 forming the outer is a part of the internal gear 55 as described above, and extends radially inward from the left end of the large diameter cylindrical portion 552 having inner teeth 551 formed on the inner peripheral surface thereof. It is a portion extending from the inside of the end wall portion 553 in the axial direction.

Inside the cylindrical portion 554, the coil spring 6 is provided.
3 storage grooves 555 for storing 2 are formed in an arc shape,
Six wedge-shaped grooves 556 are formed on the inner wall of the cylindrical portion 554 so that the radial interval increases in the circumferential direction (rotational direction).

The ring body 63 has an annular disc shape and has a projecting piece 631 facing the storage groove 555 and six projecting pieces 632 facing each wedge-shaped groove 556, and a circular groove 550 is provided around the ring groove 550. The tip of the cylindrical portion 554 is freely rotatable {the roller 61 of FIG.
It is mounted on the groove wall 557} from the contact position. The protruding piece 6
The reference numerals 31 and 632 are formed by cutting the inner circumference and bending them backward by 90 °.

As described above, the small-diameter cylindrical portion 34 forming the inner portion is a part of the center case 3, and extends axially from the inner wall of the end wall portion 33 extending radially inward from the left end of the large-diameter cylindrical portion 32. Is a portion that extends into the cylindrical portion 554 and is fitted into the cylindrical portion 554 with a gap. In the small diameter cylindrical portion 34,
A recess 341 (12) having an arc-shaped cross section for locking the roller 61
Individual pieces) are formed.

The coil springs 62 (total of 3 pieces) are open-end (polished) compression coil springs, and one end presses the wall surface of the storage groove 555 and the other end presses the projecting piece 631 inside the storage groove 555. It is stored in.

Next, the operation of the starter 1000 with a planetary gear speed reduction mechanism in which the overrunning clutch 6 is assembled will be described. When the driver operates the key switch, a current flows through the attraction coil and the holding coil of the magnet switch 4, the plunger moves, the hook 42 retracts, the shift lever 41 rotates, and the spline tube 72 (pinion gear 721). To move forward.

By moving the plunger, the electric contact of the magnet switch 4 is turned on to energize the starter motor 2 and the armature shaft 22 rotates, which causes the planet gear 54 to rotate via the sun gear 51 and the planetary gear 54 to rotate. The gear 54 tries to rotate the internal gear 55 (clockwise direction). At this time, since the coil spring 62 presses the protruding piece 631, the ring body 63 is pressed (the cylindrical portion 5
Counterclockwise direction with respect to 54}, the roller 61 is the recess 34
1, and the protruding piece 632 moves the roller 61 to the narrow side of the wedge-shaped groove 556 (the position in FIG. 4).

Therefore, the roller 61 bites between the cylindrical portion 554 and the small diameter cylindrical portion 34 to lock the cylindrical portion 554 and transmit the driving force. As a result, the rotation of the armature shaft 22 is decelerated by the planetary gear 54 and the drive shaft 7 is rotated. And spline tube 7
2 rotates forward, the rotating pinion gear 721 meshes with the ring gear 8, the ring gear 8 rotates, and the engine starts.

When the engine is started, torque {counterclockwise in the opposite direction to that during driving} is applied to the planetary gear 54 via the ring gear 8 → pinion gear 721 (spline tube 72) → drive shaft 7. At this time, the roller 61 moves to the wide side of the wedge-shaped groove 556, and
Presses the protruding piece 632, the ring body 63 is pressed (clockwise direction), and the coil spring 62 is compressed. Therefore, the overrunning clutch 6 idles and shuts off the torque to the armature shaft 22.

Starter 1 with planetary gear reduction mechanism of this embodiment
The advantages of 000 are as follows. [1] The coil spring 62 is housed in a housing groove 555 formed in the cylindrical portion 554 of the internal gear 55, and is surrounded by a groove wall. Further, the coil spring 62 presses the roller 61 via the protruding pieces 631 and 632. Therefore, during overrun or when the engine is driven, the coil spring 62 expands and contracts in the storage groove 555 without losing its posture (no tilting or bending occurs), and the coil spring 62 is prevented from being caught in the small diameter cylindrical portion 34 or the like. It is possible to prevent (when it is bitten, the coil spring 62 is damaged, and torque is not transmitted to the drive shaft 7). Therefore, the starter 10 with the planetary gear reduction mechanism in which the overrunning clutch 6 is assembled
00 has excellent durability.

[2] Since the projecting pieces 631 and 632 are integrated with the ring body 63, when the rotational driving force is applied to the cylindrical portion 554 of the internal gear 55, the projecting pieces 632 are simultaneously generated. By pressing the rollers 61, all the rollers 61 can be simultaneously moved to the narrow groove side (position (c) in FIG. 2) (behavior of the rollers 61 is stable).

Therefore, the overrunning clutch 6
The rotary drive force applied to the internal gear 55 when the engine is started can be quickly transmitted to the drive shaft 7. Therefore, the starter 1000 with the planetary gear speed reduction mechanism in which the overrunning clutch 6 is assembled is excellent in engine startability.

[3] Since the six rollers 61 are pressed by the three coil springs 62, the number of coil springs can be reduced and the cost of parts can be saved.

A second embodiment of the present invention (claims 1, 3, 4,
5) will be described with reference to FIGS. 5 and 6. In this embodiment, the ring body 63 of the overrunning clutch 6 is used.
The configuration of the storage groove 555 is different from that of the first embodiment.

The ring body 63 has a cylindrical shape, and the cylindrical portion 5
54 so as to be in pressure contact with the inner peripheral wall 554a of 54.
It is mounted between the small diameter cylindrical portions 34. Also, the ring body 63
Has six projecting pieces 632 and three projecting pieces 631 projecting in the outer circumferential direction, and holds the coil spring 62 on the outer circumference so that the coil spring 62 does not fall. Incidentally, this ring body 63
Is manufactured, for example, by cutting and bending a strip-shaped iron plate with a press or the like to form the protruding piece 632 and the protruding piece 631 and then welding both ends. The storage groove 555 is formed on the inner circumference of the cylindrical portion 554 of the internal gear 55.

The present embodiment has the effects according to the above [2] and [3] and the advantage of [4]. [4] The coil spring 62 is housed in the housing groove 555 formed in the cylindrical portion 554 of the internal gear 55, and is surrounded by the groove wall and the outer circumference of the ring body 63.
Further, the coil spring 62 presses the roller 61 via the protruding pieces 631 and 632. Therefore, when the engine is overrun or the engine is running, the coil spring 62 is inserted into the storage groove 555.
The coil spring 62 expands and contracts without losing its posture (does not fall or bend), and prevents the coil spring 62 from being caught in the small-diameter cylindrical portion 34, etc. Will not be transmitted to.
Therefore, the starter with the planetary gear reduction mechanism in which the overrunning clutch 6 of the present embodiment is assembled has excellent durability.

[Brief description of drawings]

FIG. 1 is a half sectional view of a starter with a planetary gear reduction mechanism according to a first embodiment of the present invention.

FIG. 2 is an M view of an overrunning clutch used in the starter shown in FIG.

3 is a sectional view taken along the line iii-iii in FIG.

FIG. 4 is a sectional view taken along line iv-iv of FIG.

FIG. 5 is a cross-sectional view of essential parts of an overrunning clutch used in a starter with a planetary gear speed reduction mechanism according to a second embodiment of the present invention.

FIG. 6 is a top view of FIG.

FIG. 7 is a sectional view of a one-way clutch described in Japanese Patent Application No. 6-213707.

FIG. 8 is a cross-sectional view of a general one-way clutch.

[Explanation of symbols]

 6 Overrunning Clutch (One-way Clutch) 34 Small Diameter Cylindrical Part (Inner) 61 Roller (Rolling Element) 62 Coil Spring (Elastic Body) 63 Ring Body 341 Cavity 554 Cylinder (Outer) 555 Storage Groove 556 Wedge-shaped Groove 631 Projection Installation piece (first protruding piece) 632 Projecting piece (second protruding piece)

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masanobu, 1-1, Showa-cho, Kariya city, Aichi prefecture, Nihon Denso Co., Ltd. (72) Inventor, Yasuhiro Nagao, 1-1, Showa-cho, Kariya city, Aichi prefecture Sozo Co., Ltd.

Claims (5)

[Claims] 1. A cylindrical outer member having a housing groove and a plurality of wedge-shaped grooves whose radial interval increases as it rotates in the circumferential direction, a rolling element housed in the wedge-shaped groove, and the rolling element is locked. A cylindrical inner member that has a plurality of recesses that are loosely fitted to the outer, an elastic body that is stored in the storage groove, and a first protrusion that faces the storage groove and is biased by the elastic body. One direction, characterized by including a piece and a second protruding piece that faces the wedge-shaped groove and presses the rolling element in a groove narrowing direction, and a ring body rotatably assembled to the outer side. Sex clutch. 2. The one-way clutch according to claim 1, wherein the storage groove is formed on an axial side surface of the outer, the ring body is disc-shaped, and the end surface of the ring body and the outer side are formed. A one-way clutch, characterized in that the elastic body is held between them. 3. The one-way clutch according to claim 1, wherein the storage groove is formed on an inner circumference of the outer, the ring body is cylindrical, and the elastic body is formed on the outer circumference of the cylinder of the ring body. One-way clutch characterized by holding. 4. The one-way clutch according to claim 1, wherein the number of the elastic bodies accommodated in the accommodation groove is smaller than the number of the rolling elements accommodated in the wedge-shaped groove. Characteristic one-way clutch. 5. The one-way clutch according to claim 1, wherein the elastic body is a coil spring.