JP3161064B2 - Starter clutch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch for a starter.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional starter clutch.
A pinion inner 101 is fitted to the output shaft 100 so as to be relatively rotatable and axially displaceable, and a pinion gear 102 is formed on a front outer periphery of the pinion inner 101. The inner peripheral surface at the front of the pinion inner 101, that is, the pinion gear 10
A pinion metal 107 is fitted into the inner side of the pinion 2 in the radial direction, and an inner peripheral surface of the pinion metal 107 is a bearing surface. The rear part of the pinion inner 101 is a clutch inner 103. A clutch outer 104 is fitted outside the clutch inner 103 via a wedge-shaped space S,
The rear part of the clutch outer 104 is helically spline-fitted to a spiral groove 105 formed on the outer periphery of the output shaft 100. A roller 1 for transmitting torque in one direction from the clutch outer 104 to the clutch inner 101 in the wedge-shaped space S.
06 and a clutch spring (not shown) are accommodated.

FIG. 2 shows a state in which the clutch inner gear 10 is disengaged, that is, when the pinion gear and the ring gear are not engaged.
3 covers the spiral groove 105 of the output shaft 100.
Conventionally, the clearance between the spiral groove portion 105 and the clutch outer 104 which is helically spline-fitted to the spiral groove portion 105 is relatively gradual (approximately 260- 360 μm). On the other hand, the clearance between the pinion metal 107 and the output shaft 100 is set to the above-mentioned spiral groove portion 10 in order to perform good torque transmission.
5 was set to be narrower (about 40 to 80 μm) than the clearance between the clutch outer 104 and the clutch outer 104.

[0004]

However, due to the increase in engine vibration accompanying the recent increase in engine output, the one-way clutch fitted to the output shaft of the starter is vibrated. The wear of the pinion metal 106 that supports the pinion increases, and this increase causes the pinion gear 102 to rattle at the time of transmitting the torque from the pinion gear 102 to the ring gear, causing a slight displacement of the meshing surface, and a problem that the torque transmission efficiency decreases. Was.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a clutch of a starter in which wear of a bearing surface of a pinion inner is reduced and good torque transmission from a pinion gear to a ring gear is realized. That is the purpose.

[0006]

A clutch of a starter according to the present invention is fitted to an output shaft so as to be relatively rotatable and axially displaceable, and has a bearing surface formed on a front inner periphery and a rear portion serving as a clutch inner. A pinion gear driven by a front portion of the pinion inner to drive a ring gear on the engine side; and a spiral groove portion having a front portion fitted outside the clutch inner with a wedge-shaped space and a rear portion formed on the outer periphery of the output shaft. And a roller and a clutch spring housed in the wedge-shaped space and transmitting torque in one direction from the clutch outer to the clutch inner, and an inner periphery of the rear portion of the clutch outer. The clearance between the surface and the spiral groove of the output shaft, the bearing surface of the pinion inner and the output shaft A clutch of the starter which is narrowly set than the clearance between the inner peripheral surface of the rear portion of the clutch outer is fitted portion of helical spline engagement to formed in the output shaft periphery the helical strip groove <br /> and than said engaging portion is divided into a small diameter portion formed in smaller diameter than the fitting portion positioned in front, between said small-diameter portion helical strip groove of said output shaft the clearance, the pinion inner of the is set narrower than the clearance between the bearing surface and said output shaft, said output shaft, than the small-diameter portion in the axial direction forward from the front end of said spiral strip groove A small- diameter portion smaller in diameter than the spiral groove portion over a wide width in the axial direction, and the small-diameter portion is separated from the spiral groove portion of the output shaft when the pinion gear meshes with the ring gear on the engine side. the small-diameter disengaged forward It is characterized in that facing the. In a preferred embodiment, the small diameter portion (sun)
That is, of the inner peripheral surface of the rear part of the clutch outer,
Formed in front of the part and smaller in diameter than the fitting part
Part) was fitted into the inner peripheral surface of the rear part of the clutch outer.
It is constituted by the inner peripheral surface of the ring.

[0007]

[0008]

The clearance between the spiral groove of the output shaft and the inner peripheral surface of the clutch outer covering the output shaft when the pinion gear is not meshed with the ring gear on the engine side is between the bearing surface of the front portion of the pinion inner and the output shaft. Is set to be smaller than the clearance. Therefore, when the clutch is retracted (the state in which the pinion gear is not meshed with the ring gear on the engine side), vibration of the output shaft due to engine vibration or the like is transmitted to the clutch through the fitting portion between the spiral groove of the output shaft and the clutch outer. As a result, it is not transmitted through the fitting portion between the bearing surface of the pinion inner front portion and the output shaft.

[0009]

As described above, in the clutch of the starter according to the present invention, the inner peripheral surface of the clutch outer is provided by the clearance between the output shaft and the bearing surface formed near the pinion inner front, that is, the pinion gear. Since the clearance between the spiral groove of the output shaft and the spiral groove is set to be small, the engine vibration at the time of clutch retreat is transmitted from the spiral groove to the clutch outer, and as a result, the bearing surface at the front of the pinion inner is caused by the vibration. Wear is prevented, and the torque transmission efficiency between the pinion gear and the ring gear does not decrease.

Further, when the clutch forward (meshing state between the ring gear of the pinion gear and the engine side), the engagement portion of the clutch outer is moved forward the clutch outer is disengaged forward from the spiral strip groove of the output shaft Runode, output loss is reduced by tight fit between the click Ratchiin'na and the spiral strip groove. Further, the inner peripheral surface of the clutch outer is closer to the center of gravity of the clutch than the front portion of the pinion inner, so that the runout of the clutch due to the vibration of the output shaft is reduced.

[0011]

【Example】

(Embodiment 1) An embodiment of the starter of the present invention will be described below with reference to FIG. The starter is an inertial dive type starter, and only an axial front portion (pinion gear side) is shown in an enlarged view.

The housing 1 includes a front housing 1a, a center housing 1b, and an end bracket (not shown), and a starter motor 2 is housed inside the center housing 1b. A drive shaft (output shaft in the present invention) 20 of the starter motor 2 is rotatably supported by the front housing 1 a through a bearing metal 22 at a position adjacent to the armature 21. A spiral groove 23 is formed in the drive shaft 20 in front of the bearing metal 22 adjacent to the bearing metal 22.

Further, the one-way clutch 4 is formed of the bearing metal 2.
2 and is fitted to the drive shaft 20. The one-way clutch 4 includes a clutch outer 41 and a pinion inner 4.
2, a clutch roller 43, a clutch spring (not shown), and the like. The clutch outer 41 is a cylindrical member having a large diameter at the front and a small diameter at the rear, and has an internal space S at the front with an open front end. The inner peripheral surface of the small diameter rear portion 41 a of the clutch outer 41 meshes with the spiral groove 23 of the drive shaft 20.

On the other hand, the pinion inner 42 is fitted to the drive shaft 20 in front of the clutch outer 41 so as to be relatively rotatable and relatively slidable in the axial direction. A pinion gear 45 is formed on the outer periphery of the front portion of the pinion inner 42. Have been. A pinion metal (included in the pinion inner) 46 is press-fitted into the front inner periphery of the pinion inner 42, and the inner peripheral surface (bearing surface) F of the pinion metal 46 is the drive shaft 20. Are fitted so as to be relatively rotatable and relatively slidable in the axial direction. A rear portion of the pinion inner 42 constitutes a clutch inner 47, and the clutch inner 47 is fitted into the internal space S of the clutch outer 41 so as to be coaxial with the clutch outer 41.

The inner space S of the clutch outer 41 is formed in a wedge shape in the circumferential direction.
3 is pressed by a clutch spring (not shown),
Thereby, the drive torque of the clutch outer 41 can be transmitted to the pinion inner 42. When the pinion inner 42 rotates at a higher speed, the pressing of the clutch roller 43 by the clutch spring is reduced, so that torque transmission from the pinion inner 42 to the clutch outer 41 becomes impossible.

The front end opening of the inner space of the clutch outer 41 is sealed with a half washer 48 and a wheel plate 49, and the half washer 48 and the wheel plate 49 are further sealed with the clutch outer 41.
After being fitted on the outer peripheral surface of the clutch, the clutch cover 50 is fixed by caulking. Further, a return spring 7 and a cylindrical seat 8 are fitted to the front end of the drive shaft 20, and the return spring 7 is supported by the cylindrical seat 8 locked by the locking ring 9, and is connected to the one-way clutch through a pinion metal 46. 4 in the rear direction. Due to this bias, the clutch 4 retreats to the position shown in FIG. 1 when the starter motor 2 stops, and the inner peripheral surface of the clutch inner is fitted in the spiral groove 23 of the drive shaft 20.

Next, the features of this embodiment will be described. A stepped recess 41b is formed at the front end of the small diameter rear portion 41a of the clutch outer 41, and the ring 6 having a square cross section is press-fitted into the stepped recess 41b. The inner peripheral surface of the ring 6 is slightly (about 300 μm) smaller than the remaining inner peripheral surface 41c of the rear portion 41a of the clutch outer 41, and the inner peripheral surface of the ring 6 and the drive shaft. A clearance C1 between the helical groove portion 20 and the drive shaft 20 is set smaller than a clearance C2 between the bearing surface F of the pinion inner 42 and the drive shaft 20. In this embodiment, C
1 was 30 μm, and C2 was 60 μm.

Further, when the clutch 4 moves forward, the pinion gear 45 meshes with the ring gear, and the engine is driven, the dimensions of the ring 6 and the spiral groove 23 are disengaged. Hereinafter, the operation of this device will be described. When the starter motor 2 is started by turning on the key switch, the drive shaft 20 rotates, and this rotation applies a torque to the clutch outer 41, and the clutch outer 41 advances along the spiral groove 23 while rotating, and the pinion gear 45
The one-way clutch 4 moves forward while compressing the return spring 7, and the pinion gear 45 meshes with a ring gear (not shown) to start an engine (not shown). When the engine speed increases, the one-way clutch 4 is disengaged, torque transmission from the drive shaft 20 to the clutch outer 41 disappears, and the axial thrust of the clutch outer 41, which is a component thereof, also disappears. The return spring 7 retreats the one-way clutch 4, the pinion gear 45 disengages from the ring gear (not shown), and the one-way clutch 4 retreats to the position shown in FIG.

When the one-way clutch 4 is retracted, the clearance C1 between the inner peripheral surface of the ring 6 and the spiral groove 23 of the drive shaft 20 is set between the bearing surface F of the pinion inner 42 and the drive shaft 20. Is smaller than the clearance C2 of the clutch 4, the own weight of the clutch 4 at the time of non-engagement is
, And the relative motion between the drive shaft 20 and the clutch 4 due to the vibration of the engine can be supported by the engagement between the ring 6 and the spiral groove 23,
The wear of the bearing surface F of the relatively soft pinion metal 46 due to the vibration can be prevented.

When the one-way clutch 4 advances (engages), the inner peripheral surface of the ring 6 separates forward from the spiral groove 23 of the drive shaft 20, so that the inner peripheral surface of the ring 6 and the drive shaft 20 is tightly fitted with the spiral groove 23, friction loss at this portion is eliminated, and the pinion gear 45 is carried by a pinion metal 46 which is radially inwardly adjacent to the pinion gear 45. The meshing rotation is performed smoothly and without delay.

In this embodiment, the pinion metal 46
Is provided in the pinion inner 42, but the pinion metal 46
May not be required. Further, the pinion inner 42 is formed integrally with the pinion gear 45, but may be separately connected by a direct spline or the like. Instead of press-fitting and fixing the ring 6 to the clutch outer 41, another fixing method such as caulking may be used, or clearance fit may be used. (Embodiment 2) Another embodiment will be described.

In this embodiment, when the one-way clutch 4 retreats (is not engaged), the drive shaft 2 that contacts the pinion metal 46
0 (hereinafter referred to as the reciprocating pinion metal sliding contact outer peripheral surface) with the diameter D1 of the outer peripheral surface of the drive shaft 20 which contacts the pinion metal 46 when the one-way clutch 4 advances (engages). (Referred to as an outer peripheral surface of a pinion metal sliding contact).

In this embodiment, D1 is about 10 times greater than D2.
As a result, the clearance C2 between the inner peripheral surface (bearing surface) of the pinion metal 46 and the drive shaft 20 is 160 μm when moving backward and 60 μm when moving forward.
The clearance between the inner peripheral surface of the ring 6 and the spiral groove 23 is 100 μm. In this way, the ring 6
Even if the clearance C1 between the inner peripheral surface of the helical groove portion 23 and the spiral groove portion 23 is not set so narrow, it is possible to prevent the pinion metal 46 from being worn by the engine vibration or the like at the time of retreat,
In addition, an excellent effect that the pinion metal 46 can carry the pinion gear 45 tightly at the time of forward movement can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a clutch of a starter according to the present invention;

FIG. 2 is a sectional view of a clutch of a conventional starter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Housing 6 ... Ring (part of clutch outer) 20 ... Drive shaft (output shaft) 23 ... Helical groove 4 ... One-way clutch 41 ... Clutch outer 42 ... Pinion inner 43 ... Roller 45 ... Pinion gear 46 ... Pinion metal F … Bearing surface.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F02N 15/02 F02N 15/06

Claims (2)

(57) [Claims] An engine which is fitted to an output shaft so as to be relatively rotatable and axially displaceable, has a bearing surface formed on a front inner periphery and a rear portion serving as a clutch inner, and is driven by a front portion of the pinion inner. A pinion gear for driving the side ring gear; a clutch outer having a front portion fitted outside the clutch inner with a wedge-shaped space therebetween and a rear portion fitted with a helical spline into a spiral groove formed on the outer periphery of the output shaft; A roller and a clutch spring accommodated in a space and transmitting torque in one direction from the clutch outer to the clutch inner, between the inner peripheral surface of the rear portion of the clutch outer and the spiral groove of the output shaft. Of the pinion inner is smaller than the clearance between the bearing surface of the pinion inner and the output shaft. An inner peripheral surface of the rear portion of the clutch outer is located forward of the fitting portion with a fitting portion for helical spline fitting into the spiral groove formed on the outer periphery of the output shaft. The clearance between the small diameter portion and the spiral groove portion of the output shaft is divided into a small diameter portion formed smaller in diameter than the fitting portion. The output shaft is set to be smaller than the clearance between the output shaft and the output shaft is smaller in diameter than the spiral groove over an axially wider width than the small diameter portion axially forward from the front end of the spiral groove. A small-diameter portion, wherein the small-diameter portion detaches forward from the spiral groove portion of the output shaft and faces the small-diameter portion when the pinion gear meshes with the ring gear on the engine side. Starter clutch. Wherein said small diameter portion, the rear portion of the clutch of the starter according to claim 1, characterized in that it is constituted by the inner peripheral surface of the fitting is a ring on the inner peripheral surface of the clutch outer.