JPH0531687B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a one-way clutch for use in, for example, an engine of a motorcycle.

As shown in FIGS. 1 and 2 as this type of one-way clutch, a boss portion 4 of a starting gear 3 is rotatably fitted into the center of a clutch body 2 that rotates together with a crankshaft 1. An opening 5 is provided, a plurality of recesses 6 are provided on the inner peripheral surface of the opening 5, and a cam surface 7 is formed in each recess 6 on the bottom surface thereof.
A roller 8 is rotatably sandwiched between the outer circumferential surface of the boss portion 4 and the outer circumferential surface of the boss portion 4, and this roller 8 is urged in a tangential direction against the outer circumferential surface of the boss portion 4 by a spring 9 and a cap 10. Accordingly, a device is known that allows power transmission only from the starting gear 3 side.

However, in this current specification one-way clutch, the clutch body 2 is machined from a round bar-shaped steel material, so broaching is required to form the recess 6 and cam surface 7, and the spring 9 is Drilling is required to create the housing hole 11. Therefore, there is a problem that the types of machining and the number of man-hours increase, resulting in high costs.
Moreover, since the entire clutch body 2, that is, even the parts that do not require much mechanical strength, is made of metal material, the overall quality is excessive, and improvements can be made not only in terms of cost but also in terms of weight. There was room left for.

The present invention was developed based on the above circumstances, and it is possible to reduce the need for special machining, facilitate manufacturing, and avoid excessive quality overall, thereby realizing cost reduction and weight reduction. The purpose is to provide a one-way clutch.

That is, an opening is provided in the center of the clutch body that rotates together with the rotating shaft, and the rotating member is rotatably accommodated within this opening, and an opening is provided on the inner peripheral surface of the opening. A rolling element accommodating portion is provided, and a rolling element that is pressed toward the outer peripheral surface of the rotating member is rotatably accommodated in the rolling element accommodating portion, and the clutch body and the rotating member are connected via the rolling element. In the one-way clutch which is adapted to be interlocked, the clutch body is divided into two parts: a housing part into which the rotating member is rotatably fitted, and a plate part which is rotated integrally with the rotating shaft, and the housing part is divided into two parts. The rolling element accommodating part is formed in the plate part, and a tongue part is provided on the plate part to enter into the rolling element accommodating part of the housing part and sandwich the rolling element between the outer circumferential surface of the rotating member. It is characterized by

Hereinafter, one embodiment of the present invention will be described based on FIGS. 3 to 8, in which the present invention is applied to a scooter type motorcycle.

21 in the figure is a frame, and this frame 21
is bent significantly downward between a front fork 23 that pivotally supports a front wheel 22 and a seat 24, and a footrest plate 25 is installed at the bottom of this. In FIG. 3, reference numeral 26 indicates a leg shield that protects the legs from wind, and 27 indicates a cover that covers the bottom of the seat 24.

The rear part of the frame 21 is raised upward, and the front end of an engine unit 29 is pivotally supported at the lower part of this rising part 28.
The engine unit 29 includes an engine 30 and a transmission case 32 extending rearward from one side end of a crankcase 31 of the engine 30 as an integral rigid body.A rear wheel 33 is attached to the rear end of the transmission case 32. Supported. crank case 31
A crankshaft 36 that is rotationally driven by a piston 35 in a cylinder 34 is housed inside.
One end of this crankshaft 36 has a V for rear wheel drive.
A belt transmission 37 is attached. Further, a starting gear 39 is connected to the crankshaft 36 via a bearing 38.
The starting gear 39 meshes with a pinion gear 42 of a starter motor 41 via an intermediate gear 40, and is connected to the crankshaft 36 via a one-way clutch 43 according to the present invention. This one-way clutch 43 only allows power to be transmitted from the starter motor 41 toward the crankshaft 36. Therefore, when the starter motor 41 is operated, its rotation is decelerated and the crankshaft 3
6, and the start is performed.

The details of the one-way clutch 43 are shown in FIGS. 5 through 8. That is, 44 is the clutch body, and the crankshaft 3
It is coaxially mounted on 6. This clutch body 44 is made of, for example, a housing portion 4 made of synthetic resin.
5 and a plate portion 46 made of sheet metal. The housing part 45 is molded into an annular shape having a certain thickness, and a boss part 48 of the starting gear 39, which constitutes a rotating member, is rotatably housed in a circular opening 47 opened in the center. There is. On the inner peripheral surface of the opening 47, three recesses 49 serving as rolling element housing portions are provided in the opening 47.
are formed at intervals in the circumferential direction. These recesses 49 are also continuously opened on one side of the housing portion 45 for die cutting. A cylindrical roller 50, for example, as a rolling element is housed in the recess 49 so as to be rotatable around the axis. In this embodiment, as shown in FIG. 7, both sides of the opening of the recesses 49 are bulged in the direction toward each other, and the opening width l is narrowed to be slightly smaller than the diameter r of the roller 50. Measures are taken to prevent the roller 50 from falling out of the recess 49. Further, the housing portion 45 is integrally formed with mounting grooves 51 that open on one side inner surface of each recess 49, and these mounting grooves 51 are used for mold-cutting the housing as shown in FIG. One side of the portion 45 is also opened. Pressure rods 52 are accommodated in the mounting grooves 51 so as to be able to protrude and retract into the recesses 49 , and each pressure rod 52 urges the roller 50 in the rotational direction of the boss portion 48 by a spring 53 . are doing.

On the other hand, the plate portion 46 is connected to the housing portion 45.
It is tightened and fixed to one side of the body via a screw 54, and a through hole 55 formed in the center thereof is spline-engaged with the crankshaft 36 so that it rotates together with the crankshaft 36. The plate portion 46 covers the recess 49 and one side opening of the mounting groove 51, and accommodates and holds a roller 50 in the recess 49 and a press rod 52 and a spring 53 in the mounting groove 51, respectively. On the outer periphery of the plate portion 46, tongue portions 56 facing into the recesses 49 are integrally bent and formed at positions corresponding to the respective recesses 49 by pressing. The tongue portion 56 is located on the bottom side of the recess 49 and is attached to the boss portion 4.
A roller 50 is rotatably sandwiched between the tongue portion 56 and the outer circumferential surface of the boss portion 48, and the tongue portion 56 is inclined so as to approach the outer circumferential surface of the boss portion 48 as it advances in the rotational direction of the boss portion 48. ing.

In such a one-way clutch 43, when the starting gear 39 is rotated in the direction of the arrow by the operation of the starter motor 41, the roller 50 is firmly clamped between the boss portion 48 and the tongue portion 56. Therefore, the rotation of the boss portion 48 passes through the roller 50 to the plate portion 46.
from the plate portion 46 to the crankshaft 36. When the plate portion 46 is rotated together with the crankshaft 36 when the engine 30 is started, the tongue portion 56 rotates before the boss portion 48, so that the tongue portion 56 and the boss portion 48 are The clamping pressure of the rollers 50 between them is released.
Therefore, the plate portion 46 idles relative to the boss portion 48, and no power is transmitted.

However, the one-way clutch 4 with such a configuration
According to No. 3, the power is transmitted through the boss portion 48 and the roller 50.
and through the tongue portion 56 of the plate portion 46, so that the housing portion 45 simply
0, only the holding function of the pressing rod 52 and the spring 53 can be used. Therefore, the housing portion 45 does not require great mechanical strength;
Mold molding using synthetic resin materials, aluminum, etc. is possible. In addition, since the plate portion 46 is also a press-formed product, there is no need for several types of machining as in the past, and therefore the number of machining steps can be reduced.
Cost reduction becomes possible. Moreover, by making the clutch body 44 have a two-part structure consisting of the housing part 45 and the plate part 46, each part can be constructed from materials according to their functions, and therefore the overall quality will not be excessive. This contributes to cost reduction and also makes it possible to reduce weight.

Further, in this embodiment, since the recess 49 and the mounting groove 51 are opened on one side of the housing part 45,
The recess 49 and the mounting groove 51 can also be formed at the same time when the housing part 45 is molded, which has the advantage of further contributing to the reduction in the number of work steps.

In the above-described embodiment, the housing part and the plate part were fixed by tightening with screws, but if the housing part is made of synthetic resin, for example, a protrusion may be integrally provided on one side of the housing part, and The plate portion may be provided with a through hole into which the protrusion can be inserted, and the housing portion and the plate portion may be fixed by performing so-called heat caulking, in which the protrusion is fitted into the through hole and then heated and crushed.

According to the present invention described in detail above, since the clutch body has a two-part structure consisting of the housing part and the plate part, the housing part can only have the function of holding the rolling elements. It is possible to perform molding by molding, which makes manufacturing easy and eliminates the need for special machining and processing man-hours, making it possible to reduce costs. In addition, since the housing part and the plate part can be constructed from materials that suit their respective functions, there is no need for excessive quality overall, which also contributes to cost reduction and has the advantage of being lightweight. .

[Brief explanation of the drawing]

FIGS. 1 and 2 are sectional views of a conventional example, FIGS. 3 to 8 show an embodiment of the present invention, FIG. 3 is a side view of a motorcycle, and FIG. 4 is a sectional view of an engine. Fig. 5 is a front view of the one-way clutch, Fig. 6 is a sectional view taken along line - in Fig. 5, Fig. 7 is a sectional view taken along line - in Fig. 6, and Fig. 8 is a sectional view of the housing part. It is. 36...Rotating shaft (crankshaft), 44...Clutch body, 45...Housing part, 46...Plate part,
47...Opening part, 48...Rotating member (boss part), 49
...Rolling element housing portion (recess), 50... Rolling element (roller), 56... Tongue piece portion.

Claims (1)

[Scope of Claims] 1. An opening is provided in the center of the clutch body that rotates together with the rotating shaft, and a rotating member is rotatably accommodated within this opening, and a A rolling element accommodating portion opening on the circumferential surface is provided, and a rolling element press-biased toward the outer circumferential surface of the rotating member is rotatably accommodated in the rolling element accommodating portion, and the clutch body is passed through the rolling element. In a one-way clutch that interlocks a rotating member and a rotating member, the clutch body is divided into two parts: a housing portion into which the rotating member is rotatably fitted, and a plate portion which is rotated integrally with the rotating shaft; The rolling element accommodating part is formed in the housing part, and the plate part has a tongue part that enters into the rolling element accommodating part of the housing part and pinches the rolling element between the outer circumferential surface of the rotating member. A one-way clutch characterized by the provision of a one-way clutch.