JP2537282B2 - Starter - Google Patents

Description

TECHNICAL FIELD The present invention relates to a starter, and more particularly to a pinion engaging mechanism of a starter.

[Conventional technology]

In a conventional starter, particularly a starter with a reduction mechanism, a motor shaft and a pinion shaft are connected via a reduction mechanism and a pinion clutch (one-way clutch). Specifically, for example, a reduction gear is formed on the outer circumference of the clutch outer, and this is engaged with the armature gear of the motor shaft, and further, the pinion shaft is inserted into the inner circumference of the clutch inner while being coupled via a helical spline. I am letting you.

The helical spline transmits the power of the motor to the pinion shaft and keeps the operation when shifting the pinion shaft to the ring gear on the engine side.

Further, when the pinion and the ring gear collide at the corners (gear end faces), the above structure alone does not provide sufficient torque for engaging the pinion with the ring gear. As disclosed in Japanese Unexamined Patent Publication No. 56966, in addition to the above-mentioned helical spline (first helical spline), a second helical spline (a biting assist spline) is provided at the tip side of the pinion shaft (one end near the ring gear). The pinion and the pinion shaft are connected via the pinion shaft.

In this conventional technique, in addition to engaging the pinion with the pinion shaft via the second helical spline, the pinion is axially biased by a cushion spring.

Then, when the pinion shifts together with the pinion shaft to the ring gear side, if the corners of the pinion / ring gear collide with each other, the pinion shaft remains in contact with the ring gear corner and the pinion shaft acts on the cushion spring force. I will go further against it. At this time, the pinion is displaced in the circumferential direction along the second helical spline due to the relative movement with the pinion shaft. As a result, the pinion and the ring gear can be forcibly aligned and the pinion can be engaged with the ring gear.

[Problems to be Solved by the Invention]

By the way, in the biting method using the second helical spline, the cushion spring for urging the pinion is arranged behind the pinion. Specifically, a spring stopper is fixedly arranged at the pinion rear position on the outer circumference of the pinion shaft, and a cushion spring is interposed between the spring stopper and the rear surface of the pinion.

However, according to such a cushion spring arranging structure, a mounting space for the cushion spring can be set large behind the pinion and the second helical spline, and therefore there are the following points to be improved.

 This problem will be described with reference to FIGS. 8 and 9.

FIG. 8 and FIG. 9 are explanatory views showing how a force is applied during engine cranking in a conventional example having a second helical spline that functions as a biting assist mechanism.

In these figures, 40 is a pinion shaft, 41 is a pinion clutch with a reduction mechanism, 42 is a first helical spline, 43 is a pinion, 44 is a second helical spline, 45 is a spring stopper, 46 is a cushion spring, 50 Is a ring gear and 51 is a motor shaft.

When the cushion spring 46 is located behind the pinion 43 as described above, the first helical spline 42 to the second helical spline 44 are provided by the space of the cushion spring.
The distance l to becomes longer.

Therefore, when the engine cranking is strong (when the pinion and the ring gear are engaged), the equivalent bending moment applied to the pinion clutch 41 is larger than that of the pinion 43, and the shaft portion between the first and second helical splines 42 and 44 and the pinion clutch. There was a problem in strength such that excessive stress was applied to each part.

Other factors that increase the axial length of the shaft portion between the first and second helical splines are as follows.

That is, the thickness of the tooth bottom of the pinion 43 (the portion indicated by the symbol C in FIGS. 8 and 9) needs to be maintained to some extent in order to maintain the strength. Therefore, the tooth bottom C has the eighth
As shown in FIG. 9 and FIG. 9, when one end of the cushion spring 46 is fitted on the rear surface of the pinion, the thickness of the entire pinion must be increased by that amount to secure the necessary thickness of the tooth root C. Therefore, the length l also becomes longer accordingly.

In addition, in the conventional cushion spring mounting structure, the step for fixing the spring bearing has the first and second steps on the pinion shaft.
It is formed on the shaft portion between the second helical splines 42 and 44.

Therefore, a concentrated stress of load is applied to this step portion during engine cranking.

The present invention has been made in view of the above points, and its purpose is to
In a starter of a type in which a second pinion shaft with a helical spline and a pinion are moved to a ring gear side with a cushion spring, a corresponding bending moment applied from the pinion to the pinion clutch during engine cranking is reduced to reduce the pinion shaft and the pinion shaft. An object of the present invention is to provide a starter having excellent durability by reducing excessive stress applied to each part of the pinion clutch.

[Means for solving the problem]

The present invention takes the following means in order to achieve the above object.

Hereinafter, in order to facilitate understanding of the contents, reference will be made to the reference numerals of the drawings of the embodiments.

That is, the present invention will be described with reference to the reference numerals of FIG. 1. The pinion shaft 12 that moves backward with respect to the ring gear 30 of the engine by the shift mechanism 23 and the reduction gear 2 that transmits the power of the motor to the pinion shaft 12, 5 and a unidirectional clutch (pinion clutch) 3, and the pinion shaft 12 is connected to the clutch inner 7 of the clutch 3 via the first helical spline 13 and is connected to the second side in front of the clutch 3. In the starter in which the pinion 15 is connected via the helical spline 14 of the pinion 15, the pinion 15 has a pinion sleeve 15 'integrally extended with the pinion 15 on the front surface thereof.
The spring bearing A is disposed on the pinion shaft 12, and the pinion shaft 12 has a second helical spline 14 behind the spring bearing A.
The spring bearing B is arranged at a position further forward, and the spring bearing B is
A cushion spring 16 is interposed between A and B, and the cushion spring 16 is mounted between the inner circumference of the pinion sleeve 15 'and the outer circumference of the pinion shaft 12 in front of the pinion 15 and the second helical spline 14. A stopper 19a for preventing the pinion 15 with pinion sleeve 15 'from coming off is provided on a part of the outer circumference of the pinion shaft 12, and this stopper function and the force of the cushion spring 16 enable the pinion with pinion sleeve 15'. 15 is preloaded and fitted onto the outer periphery of the pinion shaft 12, and the shaft diameter between the first and second helical splines 13 and 14 of the pinion shaft 12 is made uniform. To do.

[Action]

 According to the above configuration, the following operation is performed.

That is, the pinion shaft 12 is moved forward by the force of the shift mechanism 23 toward the ring gear 30 side of the engine, and the pinion 15
When the bump collides with the corner of the ring gear 30, first, the cushion spring 16 absorbs this shock.

Then, the pinion shaft 12 resists the force of the cushion spring 16 and advances further. At this time, the pinion 15 is in contact with the corner of the ring gear 30, but the pinion 15 is displaced in the circumferential direction on the pinion shaft 12 due to the forward movement of the pinion shaft 12 and the presence of the second helical spline 14. .

As a result, the pinion 15 reaches a position suitable for the ring gear 30, and at this time, the pinion 15 advances toward the ring gear 30 side and is bitten by the pushing force of the pinion shaft.

Further, in the present problem solving means, the cushion spring 16 of the pinion 15 can be arranged in front of the pinion 15 and the second helical spline 14 due to the arrangement structure of the spring receivers A and B.

Therefore, it is not necessary to secure the space for the cushion spring 16 behind the second helical spline 14 as in the conventional case.

As a result, the positions of the pinion 15 and the second helical spline 14 can be maximized toward the pinion clutch 3 (close to the first helical spline 13). As a result, the distance 1 between the first helical spline 13 and the second helical spline 14 can be shortened to minimize the axial length of the pinion shaft 12.

As a result, it is possible to significantly reduce the equivalent bending moment applied to the pinion clutch from the pinion 15 by meshing the ring gear during engine cranking.

Further, according to the means for solving the problem, since there is no fitting groove for fitting one end of the cushion spring to the rear surface of the pinion as in the conventional case, the thickness of the pinion can be reduced accordingly. Further, the distance 1 can be further shortened because the thickness of the pinion can be reduced.

Further, according to the above structure, the pinion shaft 12
Since it is not necessary to provide a step for fixing the cushion spring receiver (sleeve washer) between the first and second helical splines 13 and 14, there is no need to provide a step, so the shaft of the shaft portion between the first and second helical splines is The diameter can be made uniform. By eliminating this step portion, concentrated stress is not applied between the first and second helical splines 13 and 14 during engine cranking, and the strength of the pinion shaft 12 can be increased.

〔Example〕

 An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a main part of a starter according to an embodiment of the present invention, FIG. 2 is a partial sectional view showing an engaged state of a pinion and a pinion shaft thereof, and FIG. 3 shows an overall structure of the starter. It is sectional drawing shown.

As shown in FIG. 3, the starter has a motor unit 25 and a magnetic switch 24.

1 is a motor shaft, one end of which is an armature gear 2
Is formed.

A pinion shaft 12 is arranged in parallel with the motor shaft 1. As shown in detail in FIG. 1, the shaft 12 is fitted with a pinion clutch 3 via a first helical spline 13 and a pinion 15 via a second helical spline 1. .

The angle θ2 of the second helical spline 14 is larger than the angle θ1 of the first helical spline 13 (θ1 <θ2). Further, these helical splines are twisted in the opposite direction (counter-rotational direction) to the rotational direction of the pinion shaft.

The pinion 15 is formed integrally with the sleeve 15 ′ and is arranged in front of the pinion clutch 3. Sleeve 15 ′
Is extended in front of the pinion 15.

The pinion clutch 3 is composed of a clutch outer 4 with a reduction gear 5, a roller 6, a clutch inner 7, and the like.
That is, the clutch inner 7 is spline-coupled to the shaft 12 via the first helical spline 13, and both ends of the outer periphery of the clutch inner 7 are connected to the housing 9 via ball bearings 8a and 8b.
And the bearing retainer 10. The clutch outer 4 is fitted on the outer periphery of the clutch inner 7 via the roller 6, and the clutch profile provided on the outer periphery of the clutch inner 7 and the inner periphery of the roller 6 and the clutch outer 4.
11 to form a one-way clutch mechanism.

The gear 5 on the outer periphery of the clutch outer 4 meshes with the gear 2 of the motor shaft 1 to form a reduction mechanism.

 Here, the mounting structure of the pinion 15 will be described.

As shown in FIG. 2, the second helical spline 14
Comprises a shaft spline 14a provided on the outer circumference of the pinion shaft 12 and a pinion spline 14b provided on the inner circumference of the pinion 15 (pinion sleeve 15 ').

With the pinion 15 fitted, the pinion spline
14b meshes with the shaft spline 14a. Further, a third helical spline (guide spline) 19 is arranged on the outer periphery of the pinion shaft 12 in front of the shaft spline 14a. The guide spline 19 is, as will be described later, the pinion spline 14 when the pinion is assembled.
It has a function of guiding b to the shaft spline 14a side, and also has a function as a stopper for preventing disengagement of the pinion 15 after the pinion is mounted.

Inside the tip of the pinion sleeve 15 ′, the retaining ring 18 is mounted in the circumferential groove 29, and the spring cover 17 is arranged on the retaining ring 18 to form the spring bearing A.

Further, a spring bearing B is set on the pinion shaft 12 behind the spring bearing A and in front of the second helical spline 14. The spring receiver B is composed of one end of the guide spline 19. The cushion spring 16 is interposed between the spring receivers A and B. With the above mounting structure,
The cushion spring 16 is located in front of the pinion 15 and the second helical spline 14, and applies an axial force between the pinion 15 and the pinion shaft 12. Further, in this state, the pinion spline 14b is locked to the one end 19a of the guide spline 19. That is, this locking portion 19a functions as a stopper for preventing the pinion from coming off.

In this way, the pinion 15 is attached to the tip of the pinion shaft 12 while being preloaded by the cushion spring 16.

20 is a return spring, and the clutch 3 on the pinion shaft 12
It is placed behind. Reference numeral 21 is a pinion stopper, and 22 is a stopper clip.

Although the load of the pinion return spring 20 is set lower than that of the cushion spring 16, the pinion return spring 20 has a sufficient load characteristic for returning after the pinion shaft 12 advances.

Here, a process for assembling the pinion 15 into the pinion shaft 12 will be described with reference to FIGS. 4 to 6.

FIG. 4 shows a partial front view and a partial sectional view of the pinion shaft 12, and FIG. 5 shows a partial vertical sectional view and a lateral sectional view of the pinion 15.

As shown in FIG. 5, the number of teeth of the pinion spline 14b is one half of the number of spline grooves 14a '(see FIG. 4) of the shaft spline 14a meshing with the pinion spline 14b.

On the other hand, in the guide spline 19, as shown in FIG. 4, the width W ₁ of the teeth in the circumferential direction is made wider than the width W ₂ of the teeth of the shaft spline 14a, and the number of grooves is set to be smaller than that of the shaft spline 14a. It is set to one half of the number of grooves.

Further, in the grooves 14a 'of the shaft spline 14a, every other groove on which the groove 19' of the guide spline 19 does not exist is arranged. Pinion spline 14b
Width W ₃ of the groove 14b 'of a ho Isuzu equal tooth width W ₁ of the guide spline 19.

Further, immediately behind the shaft spline 14a on the outer circumference of the pinion shaft 12, when the pinion spline 14b passes through the shaft spline 14a and reaches this rear position, the spline release that releases the engagement between the pinion spline 14b and the shaft spline 14a. Zone S is formed.

Then, when the pinion 15 is incorporated into the pinion shaft 12, it is performed as follows.

FIG. 6 shows the procedure. As shown in FIG. 6 (a), first, the teeth of the pinion spline 14b of the pinion 15 are moved from the groove 19 'of the guide spline 19 on the shaft 12 side to the groove of the shaft spline 14a. Pass through 14a '.

Then, the pinion 15 is pushed in so that the pinion spline 14b completely comes out to the position of the area S behind the shaft spline 14a [Fig. 6 (b)]. In this state,
The pinion 15 is rotated in the circumferential direction so that the pinion spline 14b extends from the solid line diagonal position to the alternate long and short dash line diagonal position.

By this rotation, the teeth of the pinion spline 14b are opposed to the shaft spline groove 14a 'in which the guide spline groove 19' does not exist on the extension line of the shaft spline groove 14a '.

Then, the pinion spline 14b is moved back through the opposing spline groove 14a '[Fig. 6 (c)],
One end of the pinion spline 14b is a guide spline 19
The stopper 19a is locked to complete the mounting process.

 Next, the operation of this embodiment will be described.

When the engine is started, the pinion shaft 12 is pushed out by the shift lever 23, and at the same time, the torque generated by the motor is transmitted from the motor shaft 1 to the clutch gear 5 of the clutch outer 4 via the armature gear 2, and the roller 6 is rotated.
1st helical spline 13 of clutch inner 7 via
From the second helical spline 14 to the pinion 15. Then, when the pinion 15 is in the compatible position with respect to the ring gear 30 from the beginning, the force of the shift lever 23 and the torque of the motor act to cause the pinion 15 to be caught in the ring gear 30.

When the pinion 15 and the ring gear 30 are in contact with each other at their corners, the pushing force and the torque alone do not engage.

 The biting in this case will be described with reference to FIG.

First, as shown in FIG. 7A, when the pinion 15 comes into contact with the ring gear 30, initially, a gap G exists between the spring bearing A and the tip of the pinion shaft 12. Pinion
While 15 is in contact with the ring gear 30 and its forward movement is restricted, the pinion shaft 12 is further forwarded by the force of the shift lever 23 against the force of the cushion spring 16 [Fig. 7 (b)]. .

At this time, the gap G gradually disappears. Since the pinion shaft 12 moves by the gap G, this movement causes the pinion 15 to pass through the second helical spline 14 and the angular difference between the second helical spline 14 and the first helical spline 13. Only dislocation in the circumferential direction [7th
Figure (c)].

Then, as shown in FIG. 7D, when the pinion 15 reaches the matching position of the ring gear 30, the force of the shift lever and the force of the return spring 20 cause the pinion 15 to move forward and be engaged.

 According to this embodiment, the following effects are obtained.

Since the cushion spring 16 is arranged in front of the pinion 15 and the second helical spline 14, the positions of the pinion 15 and the second helical spline 14 are maximally moved to the clutch inner 7 side (the first helical spline 13 side). Therefore, the distance l between the first and second helical splines can be shortened.

Therefore, it is possible to minimize the equivalent bending moment of the load transmitted from the ring gear 30 of the pinion 15 during engine cranking. Therefore, the load stress applied to each part of the pinion shaft and the pinion clutch is reduced, and the durability of the starter is improved.

Since the pinion 15 is not formed with a notch for fitting the cushion spring 16, the thickness of the pinion is reduced, and the distance 1 between the first and second helical splines is further shortened by that amount, and the above-mentioned effect is enhanced. be able to.

Since the guide spline (annular projection) 19 formed integrally with the pinion shaft 12 also serves as a stopper for the cushion spring receiver B and the pinion 15, the number of parts can be reduced and the assembling work can be rationalized.

Further, when the pinion 15 is assembled to the pinion shaft 12, the pinion 15 can be pushed by the guide spline 19 toward the second helical spline 14 side, and the pinion 15 can be rotated and returned in reverse. , The starter can be easily assembled.

Since the shaft diameter of the shaft portion between the first helical spline 13 and the second helical spline 14 of the pinion shaft 12 is made uniform, the cross-sectional area of this shaft portion is increased and a concentrated load stress is applied to this shaft portion. It is possible to eliminate such problems and further increase the strength of the shaft.

In the above embodiment, the spring bearing A of the cushion spring is used.
Is incorporated in the pinion by using a separate component from the pinion 15, but it is also possible to form this integrally with the pinion 15.

〔The invention's effect〕

According to the present invention, in the starter of the type in which the pinion shaft with the first and second helical splines and the pinion are moved to the ring gear side with the cushion spring, the distance l between the first and second helical splines is Since it can be significantly shortened compared to the conventional one, it is possible to reduce the equivalent bending moment applied to the pinion clutch from the pinion during engine cranking, and moreover, in the shaft portion between the first and second helical splines of the pinion shaft, Since concentrated stress is not applied during engine cranking, load stress applied to each part of the pinion shaft and the pinion clutch can be reduced and durability of the starter can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an essential part of an embodiment of the present invention, FIG. 2 is a partial sectional view showing a state in which the pinion is fitted to a pinion shaft, and FIG. 4 is a front view and a cross-sectional view showing a part of the pinion shaft, FIG. 5 is a partial vertical cross-sectional view and a partial cross-sectional view of the pinion, and FIG. An explanatory view showing a part thereof, FIG. 7 is an explanatory view showing its operating state, and FIGS. 8 and 9 are schematic explanatory views showing a conventional example of a starter with a reduction mechanism. 1 ... motor shaft, 2,5 ... reduction gear, 3 ... pinion clutch, 4 ... clutch outer, 7 ... clutch inner, 12 ... pinion shaft, 13 ... first helical spline, 14 ... 2nd helical spline (spline for biting assistance), 14a ... Shaft spline, 1
4b …… Pinion spline, 15 …… Pinion, 16 …… Cushion spring, 19 …… Helical spline for guide (annular protrusion), 19a …… Stopper, 23 …… Shift lever, 24
...... Magnetic switch, 25 ...... Motor, A, B ...... Spring bearing.

Claims (2)

(57) [Claims] 1. A ring gear of an engine by a shift mechanism 23.
The pinion shaft 12 that moves backward with respect to 30, and the reduction gears 2, 5 that transmit the power of the motor to the pinion shaft 12.
And a one-way clutch 3, the clutch inner 7 of the clutch 3 is coupled to the pinion shaft 12 via a first helical spline 13, and a second helical spline is provided in front of the clutch 3. In a starter in which a pinion 15 is connected via a pinion 15, the pinion 15 has a pinion sleeve 15 ′ extending integrally with the pinion 15 on the front surface thereof.
5'is provided with a spring bearing A, while the pinion shaft 12 is provided with a spring bearing B at a position rearward of the spring bearing A and forward of the second helical spline 14. A cushion spring 16 is interposed between A and B, and the cushion spring 16 is provided between the inner circumference of the pinion sleeve 15 ′ and the outer circumference of the pinion shaft 12.
15 and the second helical spline 14 is mounted in front of the structure, and a stopper 19 is provided on a part of the outer circumference of the pinion shaft 12 for preventing the pinion 15 with the pinion sleeve 15 'from coming off.
a is provided, and by this stopper function and the force of the cushion spring 16, the pinion 15 with the pinion sleeve 15 ′ is preloaded and fitted onto the outer circumference of the pinion shaft 12, and A starter, characterized in that the shaft diameter between the first and second helical splines 13 and 14 is uniform. 2. An annular projection 19 is provided on the pinion shaft 12 at a position rearward of the spring receiver A and in front of the second helical spline 14, and the front surface of the annular projection 19 is the cushion spring 16a. The starter according to claim 1, wherein the starter is a spring receiver B for receiving one end of the starter and the rear surface thereof functions as the stopper 19a.