JP3111674B2 - 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. Wear of the pinion metal 106 supporting the pinion increases, and this increase causes the pinion gear 102 to rattle during transmission of torque from the pinion gear 102 to the ring gear, causing a delicate displacement of the meshing surface and a problem that the torque transmission efficiency is reduced. Was.

The present invention has been made in view of the above-mentioned problems, and reduces wear of a bearing surface near a pinion gear.
It is an object of the present invention to provide a starter clutch that achieves good torque transmission from a pinion gear to a ring gear.

[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 to the outside of the clutch inner with a wedge-shaped space and a rear portion formed on the outer periphery of the output shaft. A clutch outer fitted with a helical spline, 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. In a clutch of a starter which covers a spiral groove portion of a shaft, a spiral between an inner peripheral surface of the clutch inner and the output shaft is provided. Clearance between the groove is characterized in that the clearance from the narrow set between the bearing surface and the output shaft of the pinion inner.

In a preferred aspect, the clutch inner is disengaged from the spiral groove portion of the output shaft in a state where the pinion gear is engaged with the ring gear on the engine side.

[0008]

When the pinion gear is not meshed with the ring gear on the engine side, the clearance between the rear portion of the pinion inner covering the spiral groove of the output shaft, that is, the inner peripheral surface of the clutch inner and the spiral groove is the front of the pinion inner. It is set smaller than the clearance between the bearing surface and the output shaft.

Therefore, when the clutch is retracted (the pinion gear is not meshed with the ring gear on the engine side), the vibration of the output shaft due to engine vibration or the like is applied to the clutch through the spiral groove of the output shaft and the fitting portion of the clutch inner. As a result, the power is not transmitted through the fitting portion between the bearing surface of the pinion inner front portion and the output shaft.

[0010]

As described above, in the clutch of the starter according to the present invention, the clearance between the output shaft and the bearing surface formed close to the front of the pinion inner, that is, the pinion gear, allows the inner peripheral surface of the clutch inner to be 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 inner, that is, the rear of the pinion inner, and the bearing surface of the front of the pinion inner is vibrated. Therefore, wear is prevented, so that the torque transmission efficiency between the pinion gear and the ring gear does not decrease.

In addition, when the clutch is advanced (in a state where the pinion gear and the ring gear on the engine side are engaged), the clutch inner can be advanced and disengaged forward from the spiral groove portion of the output shaft. Output loss due to tight fitting with the spiral groove is reduced.

[0012]

【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 an internal space S whose front end is open. A small rear portion of the clutch outer 41 is engaged 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. 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 carried by the cylindrical seat 8 and biases the one-way clutch 4 in the rear direction through a pinion metal 46. I have. 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. What is important in this embodiment is that the clearance C1 between the inner peripheral surface of the clutch inner 47 and the spiral groove 23 of the drive shaft 20 is changed to the clearance C2 between the bearing surface F of the pinion inner 42 and the drive shaft 20. The point is that it is set narrower. In this example, C1 is 30 μm and C2 is 6 μm.
It was set to 0 μm.

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 causes the clutch outer 4 to rotate.
1, the clutch outer 41 rotates and advances along the spiral groove 23, the one-way clutch 4 with the pinion gear 45 advances while compressing the return spring 7, and the pinion gear 45 and the ring gear (not shown). )
Are engaged, and an engine (not shown) is started. 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 inner peripheral surface of the clutch inner 47 and the spiral groove 23 of the drive shaft 20 are moved.
Is smaller than the clearance C2 between the bearing surface F of the pinion inner 42 and the drive shaft 20, vibrations such as engine vibrations are not caused by the spiral groove 2
3 is transmitted to the inner peripheral surface of the clutch inner 47 from the top surface of the hill portion, and the pinion metal 46 is
Is not transmitted to the one-way clutch through the inner peripheral surface (bearing surface) F, and as a result, the bearing surface F of the relatively soft pinion metal 46 is prevented from being worn by this vibration.

When the one-way clutch 4 moves forward (at the time of engagement), the inner peripheral surface of the clutch inner 47 separates forward from the spiral groove 23 of the drive shaft 20, so that the inner peripheral surface of the clutch inner 47 is The tight fitting state of the drive shaft 20 with the spiral groove portion 23 is eliminated, 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 rotation of the drive shaft 2 during the engine drive or overrun is performed smoothly and without delay.
The relative slidability of the clutch inner 47 with respect to 0 is improved.

Further, the weight of the one-way clutch 4 is not applied to the pinion metal 46, and the bearing surface F of the pinion metal 46 is not worn. In this embodiment, the pinion metal 46 is provided in the pinion inner 42, but the pinion metal 46 may not be provided. In addition, pinion inner 4
2 is integrally formed with the pinion gear 45, but may be separately connected by a direct spline or the like. (Embodiment 2) Another embodiment will be described below with reference to FIG.

In this embodiment, when the one-way clutch 4 retreats (when it 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 between the inner peripheral surface (bearing surface) of the pinion metal 46 and the drive shaft 20 becomes 160 μm when retreating and 60 μm when moving forward, while the inner peripheral surface of the clutch inner 47 and the helical strip The clearance between the groove 23 is 100 μm. With this configuration, even if the clearance between the inner peripheral surface of the clutch inner 47 and the spiral groove portion 23 is not set so small, it is possible to prevent the pinion metal 46 from being worn by the engine vibration or the like at the time of retreat, And when moving forward, pinion metal 4
6 can carry the excellent effect that the pinion gear 45 can be carried.

[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 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.

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 that drives a ring gear on the side, a clutch outer whose front part is fitted to the outside of the clutch inner with a wedge-shaped space interposed therebetween, and a rear part that fits in a helical spline into a spiral groove formed on the outer periphery of the output shaft, and the wedge-shaped A starter clutch that includes a roller and a clutch spring that are housed in a space and transmit torque in one direction from the clutch outer to the clutch inner, and the clutch inner covers the spiral groove portion of the output shaft when retreating. The clearance between the inner peripheral surface of the clutch inner and the spiral groove of the output shaft is A starter clutch, wherein the clearance is set smaller than a clearance between the bearing surface of the nut and the output shaft. 2. The starter clutch according to claim 1, wherein said clutch inner is disengaged from said spiral groove portion of said output shaft in a state where said pinion gear and said engine side ring gear mesh with each other.