JPS6361502B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a starting device for internal combustion engines of automobiles and motorcycles, and in particular, the invention relates to a starting device for internal combustion engines of automobiles and motorcycles, and in particular, the invention relates to a starting device for internal combustion engines of automobiles and motorcycles. This paper proposes a starting device with good performance.

2. Description of the Related Art Conventionally, a so-called Bendix type or inertia sliding type starting device is well known as a device for starting an internal combustion engine of a motorcycle or the like. Figure 1 shows a typical example of the starting device. In FIG. 1, a clutch outer 3, which is a driving part of a one-way clutch device, is carved on the fitting surface of a rotating shaft 2 to which a driven gear 1, which receives power transmitted from a starting motor (not shown), is attached. It is slidably extrapolated in the axial direction via a helical spline 4. A pinion gear 6, which is a driven part of the one-way clutch 5, is fitted onto the rotary shaft 2 via a bearing 7 so as to be rotatable and slidable in the axial direction.
However, one end of the spring cover 9 is brought into contact with the end surface of the pinion gear 6 through the bent end portion inside the cylindrical spring cover 9, and is externally inserted. The spring cover 9 includes a large-diameter cover 9a and a small-diameter cover 9 that is approximately bowl-shaped and whose diameter is smaller by approximately the thickness of the large-diameter cover 9a.
b are connected to each other so as to be slidable in the axial direction, so that the length in the axial direction can be freely expanded and contracted.
The small diameter cover 9b is extrapolated onto the rotating shaft 2,
It is fixed by a stopper 10 so as not to move in the axial direction. Further, on the outside of the constricted portion of the clutch outer 3, a governor weight 11a having a shape obtained by dividing a disc into approximately three parts radially is supported evenly by a weight holder 11b which is fixed to the clutch outer 3 and branches into three radial parts. A centrifugal force governor device 11, which is configured by being tightened from the outside by an annular spring 11c with its elastic force and fixed integrally, is externally inserted. Furthermore, on the outside thereof, a weight guide 12 having a substantially bowl shape with a step in the A section is fitted onto the rotating shaft 2 in such a manner that the centrifugal force governor device 11 and a part of the clutch outer 3 are accommodated therein. , is fixed with a C-shaped retaining ring or pusher 13.

In the starting device configured as described above, when the starting motor (not shown) is turned on and the driven gear 1 and the rotating shaft 2 to which it is attached are rapidly rotated at high speed, the helical spline 4 functions and the clutch outer 3, A slidable one-way clutch device consisting of a clutch 5 and a pinion gear 6 slides together on the rotating shaft 2 toward the driven gear 1 in the direction indicated by the arrow by inertia. Then, when the pinion gear 6 collides with the ring gear 14 protruding nearby and receives a resistance force in the opposite direction to the above-mentioned sliding movement, the integral sliding portion starts rotating in the same direction as the rotating shaft 2, The pinion gear 6 meshes with the ring gear 14 at an appropriate position. That is, the pinion gear 6 slides while rotating, and its teeth bite into the teeth of the ring gear 14, completing the meshing of the teeth with each other. Here, since the rotating shaft 2 suddenly starts rotating at high speed, a large inertial sliding force acts on the integral sliding portion, and when the end surfaces of both the pinion gear 6 and the ring gear 14 collide and mesh, a severe impact is generated. . For this reason, the teeth of both gears are frequently damaged or the end faces are chipped, resulting in so-called end face sagging, resulting in significant wear on both gears, which is a major factor in shortening the life of the starter.

In addition, the load increases during the so-called initial stage of cranking, when the pinion gear 6 properly meshes with the ring gear 14 to start the internal combustion engine and reach stable drive, during the compression process, and when reverse rotation occurs. A large impact force is generated between both tooth surfaces,
Here too, wear and tear such as damage to gears was accelerated.

The present invention has been made in view of the above points, and by alleviating the severe impact when the pinion gear of the starter jumps into and meshes with the gear on the internal combustion engine side, the life of transmission mechanism parts such as gears can be extended. An object of the present invention is to provide a starting device for an internal combustion engine that has significantly improved durability and durability. The present invention is characterized in that a clutch outer is fitted onto a rotating shaft rotated by a starting motor via a first helical spline, and a clutch inner is configured to transmit only the rotational force from the rotating shaft to this clutch outer via a one-way clutch. In the starting device for an internal combustion engine, the clutch inner is fitted onto the rotating shaft and the pinion gear slides in the axial direction with respect to the clutch inner. A shock absorbing member is movably inserted into the clutch inner and adjacent to an end surface opposite to an end surface of the pinion gear that faces the end surface of the ring gear that engages with the clutch inner, and further, the clutch inner and the pinion gear are connected to the first helical gear. The spline is fitted with a second helical spline whose helical direction is opposite to the spline.

Next, specific embodiments of the present invention will be described based on the attached drawings. FIG. 2 is a cross-sectional view showing the starting device for a motorcycle according to the present invention, with the upper half cut away. Incidentally, parts that are the same as those in the conventional embodiment shown in FIG. 1 are designated by the same reference numerals. In FIG. 2, a driven gear 1 that receives rotation of a starting motor (not shown) is pivotally attached to one end of a rotating shaft 2. As shown in FIG. A clutch outer 3a constituting a driving section of the one-way clutch device is fitted onto the other end of the rotating shaft 2 so as to be slidable in the axial direction via a first helical spline 4a formed on the fitting surface. There is. The clutch outer 3a has an approximately two-tiered bowl-shaped outer shape, and a centrifugal force governor device 11 comprising a governor weight 11a, a weight holder 11b, and an annular spring 11c is attached to a small diameter portion of the clutch outer 3a. Centrifugal force governor device 11
In this example, three governor weights 11a each having a shape obtained by dividing a disk into approximately three parts radially are equally supported by weight holders 11b which are fixedly attached to the clutch outer 3 and are evenly branched into three prongs in a radial direction. The clutch outer 3a rotates integrally with the clutch outer 3a, and the three governor weights are rotated by the centrifugal force. 11a respectively move in the axial radial direction to enlarge the outer diameter defined by the three governor weights 11a. The weight guide 12, which has a substantially bowl shape with a step formed in the A section, accommodates and covers the centrifugal force governor device 11 and parts of the small diameter part to the large diameter part of the clutch outer 3a. It is fitted onto the rotating shaft 2 and fixed with a C-shaped retaining ring or pusher 13. On the other hand, inside the bowl-shaped large-diameter portion of the clutch outer 3a, there is a one-way clutch 5 which is constructed by combining an appropriate number of springs (not shown) and springs (not shown) and which transmits rotation only in one direction. , is attached along the inner peripheral surface of the bowl side.

According to the present invention, the driven portion of the one-way clutch 5 is divided into a substantially cylindrical clutch inner 3b and a pinion gear 6 fitted over the clutch inner 3b. This clutch inner 3b has a step formed on both its inner and outer peripheral surfaces, and one end of its large outer diameter portion is inserted into the inner clutch 3b so as to come into sliding contact with the one-way clutch 5. It is extrapolated so as to be rotatable and slidable in the axial direction. The clutch cover 5a, which is approximately bowl-shaped, is fitted over the stepped portion of the clutch inner 3b in such a manner as to hug the mouth edge of the large diameter portion of the clutch outer 3a, which also has a bowl shape. This clutch cover 5a has an insertion hole in the center that is as small as possible, and therefore not only covers the one-way clutch 5 but also restrains the clutch outer 3a and the clutch inner 3b from shifting in the axial direction. However, since the insertion hole is small, it is not easy to assemble it. However, in the present invention, since the driven portion is divided into the pinion gear 6 and the clutch inner 3b, the useful clutch cover 5a as described above can also be easily incorporated.

A pinion gear 6 is attached to the small outer diameter portion of the clutch inner 3b opposite to the large outer diameter portion that slides in contact with the one-way clutch 5, and the helical direction of the screw formed with the first helical spline 4a is opposite to the small outer diameter portion of the clutch inner 3b. In other words, it is extrapolated so as to be inertially slidable in the axial direction via the second helical spline 4b, which is formed with a reverse thread. A tooth portion 6a is provided on the outer peripheral surface of the pinion gear 6 so as to protrude around the entire circumference, so that when the pinion gear 6 is inertially slid in the direction of the arrow, it can appropriately mesh with the engine drive ring gear 14 that protrudes nearby. The structure is as follows. There is a circlip 6 at the right end of the pinion gear 6 in the figure.
b and stopper 6c are extrapolated to the clutch inner 3b, and the pinion gear is independently connected to the ring gear 14.
This prevents it from sliding to the side. Further, an escape groove 3c is carved in the clutch inner 3b adjacent to the left side of the second helical spline 4b in the figure.
As will be described later, this provides a place to escape when the pinion gear 6 collides with the ring gear 14 and moves backward.

Between the pinion gear 6 and the clutch cover 5a that covers the one-way clutch 5, two single disc springs are stacked one on top of the other in such a manner that their outer edges are aligned with each other so that the center part bulges out. Belleville spring 1
5 is extrapolated to the clutch inner 3b. One of the peripheral edges of the insertion holes formed in each of the two disc springs 15 is engaged with a step formed on the outer peripheral surface of the clutch inner 3b, while the other is in direct contact with the end surface of the pinion gear 6. are in contact with each other. Therefore, the elastic force of the disc spring 15 acts to urge the pinion gear 6 toward the ring gear 14, with the peripheral edge of the disc spring 15 engaged with the step acting as a fulcrum.

The inner circumferential surface of the clutch inner 3b, which faces the rotating shaft 2 via the bearing 7, is also formed in two stages, and the inner diameter of the end opposite to the one-way clutch 5 is ensured to be larger than the other, and the space is B is formed. This space B accommodates one end of a coil spring 8 that is fitted onto the rotating shaft 2, and its end surface is brought into contact with the stepped surface C. The other end of the coil spring 9 is housed inside the bowl of a spring cover 9 which has an elongated bowl shape and is fitted onto the rotating shaft 2, and its end surface is brought into contact with the bottom of the bowl of the spring cover 9. Spring cover 9
is fixed by a stopper 10 so as not to move in the axial direction. Therefore, the clutch inner 3b
is always urged toward the clutch outer 3a by the elastic force of the coil spring 8.

Here, the helical directions of the first and second helical splines 4a and 4b described above will be explained in detail based on FIGS. 3a and 3b and 4a and 4b. Fig. 3a is an exploded perspective view showing the first helical spline 4a carved on the outer circumferential surface of the rotating shaft 2 and the inner circumferential surface of the clutch outer 3a, and Fig. 3b shows a state in which the two are helical spline-fitted. In the schematic cross-sectional view, the solid line represents the male side helical spline carved on the rotating shaft 2, and the two-dot chain line represents the female side helical spline carved on the clutch outer 3a. Also, Figures 4a and 4b
The figures are also an exploded perspective view and a schematic cross-sectional view showing the second helical spline 4b formed on the fitting surface of the clutch inner 3b and the pinion gear 6. Comparing Fig. 3a and Fig. 4a and Fig. 3b and Fig. 4b, the helical direction of each helical spline,
That is, in plan view, the inclination direction in the schematic cross-sectional view,
It can be seen that they are in opposite directions. In the first helical spline 4a configured as above, when the rotating shaft 2 rotates as shown by arrow D, the rotational force F is decomposed into a component force F ₁ in the direction of inclination of the helical spline and a component force F ₂ in the axial direction. The clutch outer 3a is caused to inertia slide in the axial direction of the arrow E by the axial component force _F2 . On the other hand, in the second helical spline 4b, the clutch inner 3b is rotated in the same rotation direction D as the clutch outer 3a.
When it rotates, since the helical direction is opposite to that of the first helical spline, the rotational force F' is resolved into the tilt direction component force F ₁ ' of the second helical spline 4b in the axial direction, and the pinion gear 6 is rotated in the axial direction. component force
F ₂ ' causes inertial sliding in the direction of arrow E', which is opposite to the arrow E. Therefore, as will be described later, the pinion gear 6 can mesh with the mating ring gear while retracting and absorbing the severe impact during meshing, and the impact force during meshing is significantly reduced compared to the case of the prior art. Ru. As for the helical direction of each helical spline, it is sufficient that the twist directions are opposite to each other, and it is not necessary that the helical angle, that is, the inclination angle θ in each cross-sectional view in plan view, be the same. . That is, the inclination of each helical spline should be opposite to the upward right direction and the upward left direction in the respective cross-sectional views.

The operation of the above-described embodiment configured as described above will be explained below. In FIG. 2, first, a starter motor (not shown) is turned on and starts rotating, and the rotation is transmitted to the driven gear 1, and the rotating shaft 2 on which the driven gear 1 is mounted starts rotating at a high speed. First helical spline 4a on rotating shaft 2
Since the rotating shaft 2 of the clutch outer 3a that has been extrapolated has started rotating in the direction of the arrow D in FIG. receive business. For this reason, integral sliding parts such as the centrifugal force governor device 11, the one-way clutch 5, the clutch inner 3b, and the pin-on gear 6 fitted with a helical spline to the clutch inner 3b, which are integrally assembled to the clutch outer 3a, Due to the inertial sliding action, the coil spring 8 moves integrally in the axial direction shown by the arrow in FIG. Then, when the teeth 6a of the pinion gear 6 collide with the ring gear 14 protruding nearby and receive a resistance force in the opposite direction, at the same time, the first helical spline 4a
Due to this effect, the integral sliding portion from the clutch outer 3a to the clutch inner 3b starts rotating in the same direction as the rotating shaft 2. When the clutch inner 3b starts rotating, the second helical spline 4b functions, and a new sliding force acts on the pinion gear 6 in the opposite direction to the direction in which the clutch inner 3b side slides. However, since the pinion gear 6 is urged toward the ring gear 14 by the elastic force of the disc spring 15, it begins to rotate in the same direction as the clutch inner 3b while sliding in the opposite direction. The pinion gear 6 starts rotating, and the teeth 6a of the pinion gear 6 are connected to the ring gear 14.
When the pinion gear 6 reaches a position where it can properly mesh with the teeth of the clutch, the pinion gear 6 again slides together with the sliding portion on the clutch inner 3b side in the original positive direction, that is, in the direction toward the driven gear 1 side. As shown in FIG. 5, the tip of the clutch inner 3b is connected to the stopper 10.
At this point, the sliding movement in the positive direction stops, and the engagement of the pinion gear 6 with the ring gear 14 is completed. As described above, the pinion gear 6 retreats at the moment it collides with the ring gear 14, that is, moves while escaping in the shock absorbing direction, and meshes with the ring gear 14 appropriately. Therefore, compared to the case of the prior art in which the operation from the protrusion of the pinion gear 6 to the engagement is completed in one step, the impact force caused by the collision between the gears is significantly reduced.

After the pinion gear 6 is properly engaged with the ring gear 14, it rotates in synchronization with the rotating shaft 2, rotates the ring gear 14, and drives the engine. In the initial stage of engine operation, the load applied to the pinion gear 6 is very large, and the pinion gear 6 itself is rotated at high speed in synchronization with the rotating shaft 2, so there is a large impact between the tooth surfaces of the pinion gear 6 and the ring gear 14. force is generated. However, in this embodiment, the pinion gear 6 and the clutch inner 3
The second helical spline 4b interposed between the two helical splines 4b transforms the impact force into the axial direction and relieves it.
That is, the pinion gear 6 can slide in the opposite direction by the axial width of the relief groove 3c, and the impact force can be absorbed by that amount. Further, at the beginning of this drive, as mentioned above, abnormal operations such as the butt phenomenon are likely to occur, but the impact in this case is also alleviated as described above.

Also, at this time, the centrifugal force governor device 11 attached to the outer peripheral surface of the clutch outer 3a rotates integrally with the clutch outer 3a, and the three governor weights 11a each have a spring wound around the outside by centrifugal force. It moves radially in a floating manner against the elastic tightening force of the weight guide 11c, and comes into contact with the inner circumferential surface of the large diameter portion of the weight guide 12 beyond the step A. Therefore, by the time the pinion gear 6 is engaged and the ring gear 14 is rotationally driven, the rotation of the engine is reduced and the pinion gear 6 is inadvertently disengaged from the ring gear 14. and prevent their departure.

Eventually, when the engine reaches stable driving and the starting motor is turned off and the rotating shaft 2 stops, the clutch outer 3a is also disengaged from the one-way clutch 5 and starts to stop, but is dragged by the rotation of the clutch inner 3b via the one-way clutch 5. Therefore, due to the effect of the first helical spline 4a, a considerably large inertial sliding force in the opposite direction that returns to the weight guide 12 side acts on the clutch outer 3a, and the elastic force of the coil spring 8 also acts on the clutch outer 3a.
The integral sliding portion from a to the pinion gear 6 is strongly pressed in the opposite direction. Also, clutch outer 3a
When it comes to a near stop, the centrifugal force acting on the governor weights 11a of the centrifugal force governor device 11 attached to the outer periphery also substantially disappears, so each governor weight 11a returns to its original state due to the elastic tightening force of the spring 11c. Return to the outer periphery of the clutch outer 3a to reduce the enlarged outer diameter and release the stopper function. Therefore, at the same time that the starting motor is turned off and the stopper function of the centrifugal force governor device 11 is released, the above-mentioned strong pressing force is instantaneously applied, and the integral sliding portion is subjected to a severe impact, causing the stopper function of the centrifugal force governor device 11 to be released. After returning to the position, the pinion gear 6 separates from the ring gear 14.

As detailed above, according to the present invention, the driven portion of the one-way clutch is divided into at least two parts and a shock absorbing member is appropriately incorporated, thereby significantly reducing the shock when the pinion gear jumps into engagement with the ring gear. can do. Further, by carving another helical spline having a different helical direction from the diving helical spline on the divided surface of the driven portion, various impacts can be more effectively alleviated. Therefore, the life of the teeth of the pinion gear, etc. can be extended, and the durability of the starter can be greatly improved. Further, by dividing the driven part, it becomes easy to assemble accessory parts such as a clutch cover, and it is also possible to diversify the specifications of the pinion gear, which promotes cost reduction of the starting device.
It should be noted that the present invention is not limited to the specific embodiments described above, and it goes without saying that various modifications can be made within the technical scope of the present invention. for example,
The number of disk springs is not limited to two, but three or more may be used in combination, and the driven portion may be divided into three or more.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the upper half of a conventional starting device for a motorcycle, and FIG. 2 is a sectional view of the upper half of the starting device for a motorcycle, which is an embodiment of the starting device according to the present invention, before starting. Figures 3a and 3b are exploded perspective views and schematic cross-sectional views of the first helical spline provided in the first embodiment, and Figures 4a and 4b are the same as in the first embodiment. FIG. 5 is an exploded perspective view and a schematic cross-sectional view of the second helical spline provided, and FIG. 5 is a cross-sectional view with the upper half cut away showing a state in which the pinion gear of the first embodiment is meshed with the ring gear. Explanation of symbols, 3, 3a: Clutch outer, 3
b: clutch inner, 4, 4a: first helical spline, 4b: second helical spline, 6:
Pinion gear, 15: Belleville spring.

Claims (1)

[Claims] 1. A clutch outer is fitted with a first helical spline to a rotating shaft rotated by a starting motor, and is connected to a clutch inner that transmits only the rotational force from the rotating shaft to this clutch outer via a one-way clutch, and is integrated with this clutch inner. In the starting device for an internal combustion engine, the clutch inner is fitted onto the rotating shaft, and the pinion gear is fitted onto the clutch inner so as to be slidable in the axial direction with respect to the clutch inner. , a shock absorbing member is adjacent to an end surface opposite to an end surface of the pinion gear that faces the end surface of the ring gear that meshes with the ring gear, and further, the clutch inner and the pinion gear have helical directions opposite to that of the first helical spline. A starting device characterized in that the starting device is fitted with a second helical spline.