JPS6275141A - Power transmission device of engine - Google Patents

Abstract

PURPOSE:To reduce the number of parts by using a plate portion of a one-way clutch as a part of parts of a centrifugal clutch in common. CONSTITUTION:A clutch main body 11 of a one-way clutch 10 is split into a housing portion 12 and a plate portion 13, and the plate portion 13 is integral with fitting portions 29, 29 for clutch weights 28, 28 of a centrifugal clutch 25. As each one end portion of the clutch weights 28, 28 is pivoted on the fitting portions 29, 29, the plate portion 13 can be used as a part of parts of the centrifugal clutch is common. Thus, the one-way clutch 10 and the centrifugal clutch 25 are united in a body to reduce the number of parts.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power transmission device incorporated in, for example, an engine for a motorcycle.

[Prior art]

Conventionally, in this type of motorcycle engine, there is a one-way clutch on the crankshaft that only allows power transmission from the starter to the crankshaft, and when the rotational speed of the crankshaft does not reach a certain value, The power of the crankshaft is V
A device equipped with a centrifugal clutch that transmits power to a belt-type transmission is known.

□ [Problem that the invention seeks to solve] 1
, ka, ika 38, conventional. ,,,＞. Place. Since the clutches of the first and second types are each independently attached to the crankshaft, the number of parts increases, and there is room for improvement in terms of weight and cost.

Furthermore, since the clutch is attached to the crankshaft at three or three locations, the axial length of the crankshaft becomes correspondingly longer, resulting in a disadvantage that the compactness of the power transmission system is impaired.

[Means for solving problems]

Therefore, in the present invention, a one-way clutch is provided on the rotating shaft, which allows only power transmission from the rotating member to the rotating shaft;
It is assumed that the engine is equipped with a centrifugal clutch that transmits the power of the rotating shaft to the driven member when the rotational speed of the rotating shaft reaches a certain value, and the one-way clutch is located at the center of the clutch body that rotates together with the rotating shaft. The rotary member has an opening into which the boss of the rotating member rotatably fits, and the rotary member is rotatably clamped between the boss and the outer circumferential surface of the boss in a recess provided on the inner circumferential surface of the opening. On the other hand, the centrifugal clutch accommodates rolling elements that rotate together with the driven member, rotates together with the rotating shaft, and protrudes outward due to the centrifugal force that accompanies this rotation. The clutch body of the one-way clutch is configured to accommodate a clutch weight that contacts the inner circumferential surface of the X-shaped leg in a manner that allows it to move toward and away from the inner circumferential surface of the X-shaped leg. and a housing portion having a concave portion, and the housing portion and the plate portion are overlapped and connected to each other, and the plate portion is present in the concave portion and the rolling element is sandwiched between the boss portion and the housing portion. The clutch weight part is integrally bent to the outer periphery of the plate part, and one end of the clutch weight is rotatably supported on the part. It is characterized by what it did.

[Effect]

According to this configuration, the plate portion of the one-way clutch can be commonly used as a part of the centrifugal clutch, and the one-way clutch and the centrifugal clutch are integrated into a unit. As a result, there is no need for any parts for supporting the clutch on the rotating shaft, so the number of parts can be reduced accordingly, and costs can be reduced.

In addition, since both clutches are mounted on the rotating shaft at the same location, the length of the rotating shaft can also be shortened.
Therefore, in combination with the above-mentioned reduction in the number of parts and unitization, it becomes possible to make the power transmission system smaller and lighter.

[Embodiments of the invention]

An embodiment of the present invention will be described below based on drawings in which the present invention is applied to an engine for a motorcycle.

A crankshaft 2 serving as a rotating shaft is supported within a crankcase indicated by cylinder number l in FIG.

A rotary member, in the case of this embodiment, a boss portion 6 of a starting gear 5, is pivotally supported by the journal portion 3 of the crankshaft 2. The starting gear 5 meshes with a pinion gear 9 of a cell starter 8 via an intermediate gear 7, and the boss portion 6 of this starting gear 5 engages with the journal portion 3 via a one-way clutch 10.
is connected to.

This one-way clutch 10 connects the starting gear 5 to the crankshaft 2.
The details will be explained with reference to FIGS. 2 to 5.

That is, the reference numeral 11 in the figure is a clutch body, and the clutch body 11 is divided into two parts: a housing part 12 made of synthetic resin and a plate part 13 made of sheet metal. The housing part 12 is molded into a disc shape with a constant wall thickness, and has an opening 14 in the center thereof into which the boss part 6 is rotatably fitted.
is formed. Three recesses 15 are formed on the inner peripheral surface of the opening 14 at equal intervals in the circumferential direction, and these recesses 15 are opened on one side of the housing portion 12. Inside each recess 15, a cylindrical roller 1 is provided as a rolling element.
These rollers l[i are biased in the direction of rotation of the boss part 6 via a spring 17 and a pressing rod 18 housed in the housing part 12.

Further, the plate portion 13 is coaxially overlapped with one end surface of the housing portion 12, and is fastened to this one end surface via a screw 19.
3, an engagement hole 20 is formed in the center of the journal portion 3 for spline engagement with the journal portion 3. Therefore, due to this engagement, the housing portion 12 and the plate portion 13 are rotated together with the crankshaft 2.

A tongue portion 21 that passes through one end surface of the housing portion 12 and is present in each recess 15 is integrally bent and formed on the outer peripheral edge of the plate portion 13 . The tongue portion 21 rotatably sandwiches the roller 1B between the tongue portion 21 and the boss portion 6, and as the tongue portion 21 advances in the rotational direction of the boss portion 6, the tongue portion 21 approaches the outer circumferential surface of the boss portion 8. is inclined to.

Therefore, when the starter gear 5 is rotated in the direction of the arrow in FIG. 3 by the cell starter 8, the roller IB is firmly sandwiched between the boss portion 6 and the tongue portion 21.

Therefore, the rotation of the boss portion 6 is transmitted to the plate portion 13 through the roller 16, and is also transmitted from the plate portion I3 to the crankshaft 2.

When the engine is started, the plate portion 13 and the crankshaft 2 rotate together, and the tongue portion 21 rotates in advance of the mouth 16, so that the pinching pressure of the roller 16 is released. Therefore, the plate portion 13 idles relative to the boss portion 6, and no power is transmitted from the crankshaft 2 to the starting gear 5.

On the other hand, a primary sheave 23 of a V-belt type transmission 22 is rotatably supported on the journal portion 3 as a driven member, and this primary sheave 23 is connected to the journal portion 3 via a centrifugal clutch 25. has been done. This centrifugal clutch 25 transfers the power of the crankshaft 2 to the primary when the rotational speed of the crankshaft 2 reaches a certain value.
It is transmitted to the sheave 23, and the one-way clutch 1
It is installed adjacent to the plate section 13 of No. 0. This centrifugal clutch 25 will be explained with reference to FIG. 6. Reference numeral 26 denotes a clutch housing, which is coaxially connected to one end surface of the briny loop 23. The clutch housing 26 has a circumferentially continuous flange wall 27 on its outer periphery, and a pair of arcuate clutch weights 28.degree. 28 are disposed inside the flange wall 27. And these clutch weights 28.2
8 is adjacent to the outer end surface of the plate portion 13,
One end portion thereof is supported by the plate portion 13.

That is, on the outer circumferential portion of the plate portion 13, plate-shaped attachment portions 29 and 29 that project outward are integrally molded at three locations facing each other in the radial direction of the journal portion 3; One end portion of the clutch weights 28, 28 is rotatably supported on the .29 via a pivot shaft 30. When the rotational speed of the plate portion 13 reaches a certain value, these clutch ways 1-28°28 are rotated by the centrifugal force and protrude outward.
The clutch shoe 31 attached to the outer circumferential surface of 8.28 comes into contact with the inner surface of the flange wall 27, and due to the frictional force accompanying this contact, the rotation of the crankshaft 2 is transmitted to the primary sheave 23 through the clutch housing 2G. .

Note that a return spring 33.33 is installed between both ends of the clutch weight 28.28 to bias the clutch weight 28.28 inward.

According to such a configuration, the clutch body 11 of the one-way clutch IO is divided into the housing portion 12 and the plate portion I3, and the clutch weights 28 and 28 of the centrifugal clutch 25 are attached to the plate portion 13. The parts 29, 29 are integrally formed, and one end of the clutch weight 28, 28 is rotatably supported on the parts 29, 29, so that the plate part 13 is connected to the centrifugal clutch 25, 29. It can be commonly used as part of the parts.

Therefore, since the one-way clutch 10 and the centrifugal clutch 25 are integrated into a unit, there is no need for special parts for supporting the clutch weight 28°28 on the journal part 3, and the number of parts can be reduced accordingly. Cost reduction becomes possible.

Furthermore, both clutches 10.
25 is installed at a common location, the axial length of the crankshaft 2 can be shortened, and this, combined with the above-mentioned reduction in the number of parts and unitization, makes it possible to make the power transmission system smaller and lighter. .

Note that the engine power transmission device according to the present invention is not limited to use in motorcycles, but can also be used in other vehicles and general-purpose engines other than vehicles.

〔Effect of the invention〕

According to the present invention described in detail above, since the one-way clutch and the centrifugal clutch are integrated into a unit, the number of parts can be reduced and costs can be reduced.

In addition, since both clutches are attached to the rotating shaft at the same location, the rotating shaft can be shortened accordingly.
Coupled with the above-mentioned reduction in the number of parts and unitization, it becomes possible to make the power transmission system smaller and lighter.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a sectional view of the entire device, FIG. 2 is a side view of the one-way clutch, FIG. 3 is a sectional view of the one-way clutch, and FIG. 4 is a sectional view of the one-way clutch. 5 is a side view of the plate portion, and FIG. 6 is a side view of the centrifugal clutch side. 2... Rotating shaft (crankshaft), 5... Rotating member (starting gear), 6... Boss part, 10... One-way clutch, 11... Clutch body, X2... Housing part ,
13...Plate part, 14...Opening part, 15...
Recessed portion, 1B... Rolling element (roller), 21... Tongue piece portion, 23... Driven part sheave (primary sheave), 25.
...Centrifugal clutch, 2B...Clutch no./Using,
28...Clutch weight, 29...Installation is part.

Claims (1)

[Claims] A one-way clutch on the rotating shaft that allows only power transmission from the rotating member to the rotating shaft, and a one-way clutch that transmits the power of the rotating shaft when the rotational speed of the rotating shaft reaches a certain value. In an engine equipped with a centrifugal clutch that transmits information to a member, the one-way clutch has an opening in the center of a clutch body that rotates together with a rotating shaft, into which a boss portion of the rotating member is rotatably fitted; A rolling element rotatably held between the outer circumferential surface of the boss part is accommodated in a recess provided on the inner circumferential surface of the opening, while the centrifugal clutch is a clutch housing that rotates integrally with the driven member. The one-way clutch houses a clutch weight that rotates integrally with the rotating shaft and protrudes outward due to the centrifugal force accompanying this rotation, and contacts the inner circumferential surface of the clutch housing so as to be able to come into contact with and separate from the clutch housing. The clutch body is divided into a metal plate part that rotates together with the rotating shaft and a housing part having the above-mentioned opening and recess, and the housing part and the plate part are overlapped and connected to each other. A tongue portion that is present in the recess and that sandwiches the rolling element with the boss portion is integrally bent on this plate portion, and a mounting portion for the clutch weight is provided on the outer periphery of the plate portion. 1. A power transmission device for an engine, characterized in that the clutch weight is integrally formed and one end of a clutch weight is rotatably supported on the mounting portion.