JPH0155325B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a one-way clutch used, for example, in motorcycles.

Conventionally, automatic transmissions that do not require gear shifting operations have been widely used in small two-wheeled motor vehicles called family bikes. This automatic transmission is configured to transmit only the rotation of a predetermined speed change gear in one direction among a plurality of speed change gears to a driven shaft, and these speed change gears and the driven shaft are each connected by a one-way clutch. ing. That is, this one-way clutch is composed of a ratchet wheel and a pawl that is biased by a spring in a direction that engages the ratchet of the ratchet wheel. For example, when the ratchet wheel is on the transmission gear side, Since the pawl is provided on the driven shaft side, rotation of the transmission gear in one direction can be transmitted to the driven shaft via the ratchet wheel and the pawl.

However, when the speed change gear and the driven shaft are relatively rotated in a direction in which the ratchet and the pawl do not engage, the pawl is biased in the direction in which the pawl engages with the ratchet. The tip of the ratchet rotates to follow the shape of the ratchet. Therefore, the tip of the pawl is repeatedly struck by the ratchet, and due to this repetitive movement, the proximal end of the pawl is repeatedly worn against the driven shaft side, causing the pawl to become damaged. There was a problem where the product was damaged. Furthermore, since the spring is also subjected to repeated loads due to the repetitive motion, this spring may also be damaged. Further, the repetitive motion has the disadvantage that the tip of the pawl is struck by the ratchet, resulting in unpleasant noise.

The present invention has been made based on the above circumstances, and its purpose is to eliminate the repeated movement of the pawl so that the pawl does not undergo repeated wear, and the pawl can be moved in one direction without the noise. The goal is to provide clutches.

Therefore, in the present invention, in order to achieve the above object, a rotating body that rotates integrally with a rotating shaft and a rotating wheel that covers the outer periphery of this rotating body are provided so as to be relatively rotatable, and the outer circumferential surface of these rotating bodies A ratchet is formed on either one of the inner circumferential surfaces of the rotary wheel body, and a pawl is provided on the other side that is always biased in a direction to mesh with the ratchet, and the meshing of these ratchets and the pawl causes the rotary body to rotate. In a one-way clutch configured to integrally rotate the wheel body in only one direction, a plate that can be rotated together with the rotary body and the rotary wheel body is pressed into contact with the rotary body and the rotary wheel body, straddling the side surfaces of the rotary body and the rotary wheel body, This plate is formed with an engaging hole into which the pawl is fitted with play, and the rotary body or rotating wheel is provided at the opening periphery of the engaging hole in a direction in which the pawl slides into contact with the pawl and the ratchet does not mesh with each other. When the body is rotated,
The present invention is characterized in that a cam is formed to press the pawl in a direction away from the ratchet.

The present invention will be explained below based on an embodiment shown in the drawings.

Figure 1 shows a two-wheeled motor vehicle, where 1 is the main body, 2
3 is a steering wheel, 3 is a front fork, 4 is a steering wheel, 5 is a seat, and 6 is a driving wheel. For example, a two-stroke single-cylinder engine 7 is loaded in the lower part of the vehicle body 1, and this engine 7 is equipped with a crank case 9 on the rear side of a cylinder 8, with a cylinder head 10 facing forward and a cylinder shaft extending from the vehicle body. They are arranged along the front-rear direction of the main body 1.

However, the crank case 9 of the engine 7
The automatic transmission 11 incorporated therein uses one-way clutches 12, 12 according to the present invention. This automatic transmission 11 is shown in FIG. 2, and will be explained below based on this. 13
1 is a crankshaft, and although this crankshaft 13 is not shown, it is connected to the piston of the cylinder 8 through a connecting rod. A flywheel magneto (not shown) is installed at one end of the crankshaft 13, and a primary gear 14 and a centrifugal clutch 15 are installed at the other end. In addition, 16 is a clutch plate of the centrifugal clutch 15, 17 is a clutch weight attached to this clutch plate 16 via a pin 18, and 19 is a clutch housing. And this clutch housing 1
9 is welded to a first output gear 20 rotatably provided on the crankshaft 13 via a pusher, and the clutch housing 19 is adapted to rotate together with this first output gear 20. .
Further, a second output gear 21 having a larger diameter than the first output gear 20 is rotatably provided at the back of the clutch housing 19, that is, at the other end of the crankshaft 13 via a pusher. This second output gear 21 is provided with a transmission centrifugal clutch 22, and 23 is a transmission centrifugal clutch 22.
The clutch plate 24 is a clutch weight attached to the clutch plate 23 via a pin 25. Note that 26 is a drive gear for driving the oil pump, and 27, 27 are linings.

On the other hand, 28 is a driven shaft, and this driven shaft 28 is supported parallel to the crankshaft 13. A first speed gear 29 and a second speed gear 30 are rotatably fitted into the other end of the driven shaft 28 via a sleeve.
It has a larger diameter. And these gears 29
and 30 are provided with boss portions 29a and 30a of the same diameter, and these gears 29 and 30 are arranged on the driven shaft 28 with the respective boss portions 29a and 30a facing each other and their opposing surfaces in sliding contact. has been done. Note that the first speed gear 29 meshes with the first output gear 20, and the second speed gear 30 meshes with the second output gear 21. A torsion coil spring 31 is continuously wound around the outer peripheral surfaces of the boss portions 29a, 30a of the first gear 29 and second gear 30. That is, this spring 31 is connected to the boss portions 29a, 3
It is wound around the outer peripheral surface of 0a with a predetermined tightness in the radial direction, and both end surfaces thereof are formed into a planar shape so that they slide on the end surfaces on the boss side of the first gear 29 and second gear 30, respectively. Pressure-welded freely. The winding direction of the spring 31 is along the rotational direction of the first and second gears 29 and 30, and when the first gear 29 reaches a rotational speed above a certain level, its inner surface is aligned with the boss portions 29a and 30a. It is firmly fitted to the outer periphery, and the 1st gear 29 and 2nd gear 3
0 are connected together.

Then, the first gear 29 and the second gear 30
are connected to the driven shaft 28 via one-way clutches 12, 12 that transmit only rotation from these gears 29 and 30, respectively. These one-way clutches 12, 12 have the same structure and are connected to the first gear 2.
The one-way clutch 12 that connects the first speed gear 29 and the driven shaft 28 will be described here. This one-way clutch 12 is shown in FIGS. 3 and 4, and this one is shown in FIGS.
One-way clutch body 3 shown in figures to figures 7
2 and a contact release member 33. This one-way clutch main body 32 is composed of a boss one-way complete 34 as a rotating body and a sleeve 35 as a rotating wheel body. The complete member 34 is spline-engaged with the driven shaft 28 and is rotatable together with the driven shaft 28. Further, the sleeve 35 coaxially covers the outer periphery of the complete 34, and its inner circumferential surface faces the outer circumferential surface of the complete 34. It is rotatable. A ratchet 36 is formed on the inner peripheral surface of the sleeve 35, and pawls 37, 37 that can be engaged with the ratchet 36 are provided on the outer peripheral surface of the complete 34. As shown in FIG.
It stands out more than that. Further, each of the pawls 37 is always urged in the direction of engagement with the ratchet 36 by the tension of a pawl spring 38. That is, the pawl spring 38 presses the base of each of the pawls 37 in the direction C shown in FIG. has been done. The contact release member 33 is formed of a circular plate 39, and a mounting hole 39a is formed in the center of the plate 39, and the pawl 37,
Engagement holes 40, 40 are formed into which 37 can be loosely fitted. This plate 39 has the above-mentioned mounting hole 39a.
The complete 34 and the sleeve 3 are fitted onto the driven shaft 28 via
It is in contact with the side of 5. And the engaging hole 40,
As shown in FIG. 6, 40 has a long hole shape along the rotational direction of the complete 34 and sleeve 35, and there is a gap between both ends along the rotational direction and the pawls 37, 37. Existing. At the same time, the opening peripheries on the outer peripheral side of the engaging holes 40, 40 are always in sliding contact with the pawls 37, 37,
The opening peripheral portions of the engaging holes 40, 40 form a cam 40a that extends obliquely toward the outside in the radial direction of the plate 39 at an intermediate portion thereof. This cam 4
0a presses the pawls 37, 37 inward in the radial direction of the complete 34 against the urging force of the pawl spring 38 when the plate 39 is rotated in the direction of arrow A in FIG. This pawl 37 is tilted in a direction away from the ratchet 36. and driven shaft 2
A transmission centrifugal clutch 41 is provided at one end of the transmission clutch 8, 42 is a clutch plate of this transmission clutch 41, and 45 is a clutch housing. A compression spring 46 is wound around the outer peripheral surface of the boss portion of the clutch plate 41, and one end side of this compression spring 46 is brought into contact with the plate 39 on the first speed gear 29 side. At the same time, the other end side is in contact with the end surface of the boss portion. The compression spring 46 acts in a direction to compress the first gear 29 and the second gear 30 between it and a stopper 47 provided on the side surface of the plate 39 on the second gear 30 side. Sleeve 3 of each one-way clutch 12
5 and the complete 34, a predetermined frictional resistance acts on the sides thereof.

Further, a third speed gear 48 is rotatably fitted into one end of the driven shaft 28, and an arm portion of the third speed gear 48 is connected to the clutch housing 48.
It is fixed at 5. And this third gear 48
has a smaller diameter than the second gear 30, and
It meshes with the primary gear 14 mentioned above. Note that 49 is a dock gear in a starting mechanism (not shown). One end side of the driven shaft 28 is connected to the drive wheel 6.

Next, the operation of the above configuration will be explained. When the rotational speed of the crankshaft 13 is low, such as during idling, sufficient centrifugal force is not yet applied to the clutch weight 17 of the centrifugal clutch 15, so that it is not applied to the clutch housing 19. On the other hand, when the rotational speed of the crankshaft 13 exceeds the idling speed, the clutch weight 17 acts to shift the first output gear 20 through the clutch housing 19.
is rotated, and the first speed gear 29 that meshes with this output gear 20 is rotated. In this case, the first gear 29 is rotating in the direction in which the torsion coil spring 31 tightens, so when the rotation speed of the first gear 29 reaches a certain level or more, the torsion coil spring 31 and the outer peripheral surfaces of both boss portions 29a, 30a of the second speed gear 30,
Second gear 30 is also rotated at the same speed. And 1
The rotational force of the speed gear 29 is transmitted to the driven shaft 28 via the one-way clutch 12. That is, in this case, the one-way clutch 1 is moved in the direction of arrow B in FIG.
Since the second sleeve 35 is rotated together with the first speed gear 29, the plate 39 also tends to rotate together with the sleeve 35 in the same direction. That is, plate 39
is for sleeve 35 and complete 34,
These sleeves 3 are arranged so that a predetermined frictional force is generated.
5 and the sides of the complete 34, the plate 39 rotates with a deviation in the direction of arrow B relative to the complete 34 by the amount of play between the pawls 37, 37 and the engagement holes 40, 40. For this reason, the engagement holes 40, 40 also have the poles 37,
37, the pressure on the pawls 37, 37 by the cam 40a is released, and the pawl 3
7 and 37 are engaged with the ratchet 36 by the biasing force of the pawl spring 38, and the rotation of the first speed gear 29 is transmitted to the driven shaft 28.
The rotational force of the driven shaft 28 is then transmitted to the drive wheel 6 to drive the drive wheel 6.
This is the power transmission path in first gear.

Therefore, when the driver continues to open the throttle to increase the vehicle speed, the rotation speed of the crankshaft 13 increases, and the rotation speeds of the first gear 29 and the second gear 30 increase. The second gear 30 is the second gear.
Therefore, when the second output gear 21 reaches a rotational speed above a certain level, the clutch housing 19 is connected to the second output gear 21 by the action of the clutch plate 23 and rotates as a unit. do. In this case, since the mutual reduction ratios of the second output gear 21 and the second speed gear 30 are set smaller than the mutual reduction ratios of the first output gear 20 and the first speed gear 29, the clutch housing 19 is It will be rotated before the weight 17. In this state, the rotational speed of the second gear 30 exceeds that of the first gear 29, and a force that tries to rotate the torsion coil spring 31 wound around both bosses 29a and 30a in the tightening direction is generated. is canceled. Therefore, the torsion coil spring 31 and the boss portions 29a, 30a are in sliding contact with each other, and the spring 31 is connected to the second gear 3.
The function of transmitting zero rotational force to the first gear 29 is lost. Therefore, the rotational force of the second gear 30 is transmitted to the driven shaft 28 via the one-way clutch 12, as in the case of the first gear, and the reduction ratio of the driven shaft 28 becomes smaller, resulting in a shift up to the second gear. .

In this operating state in second gear, the above 1.
The rotational force of the speed gear 29 is not transmitted to the driven shaft 28 via the one-way clutch 12 on the side of the first speed gear 29. That is, since the rotational speed of the driven shaft 28 exceeds the rotational speed of the first speed gear 29, the sleeve 35 of the one-way clutch 12 rotates relative to the complete 34 in the direction A shown in FIG. will be done. Therefore, the ratchet 36 and each pawl 37 of the one-way clutch 12
Since the rotational force of the first speed gear 29 is not transmitted to the driven shaft 28, the rotational force of the first speed gear 29 is not transmitted to the driven shaft 28.

At this time, the plate 39 of the one-way clutch 12 is pressed against the side surfaces of the sleeve 35 and the complete 34 so that a predetermined frictional resistance is generated between them. At the same time, it is shifted and rotated in the A direction. Therefore, due to the misalignment of the engagement holes 40, 40 of this plate 39,
As shown in FIG. 4, the cam 4 of the engaging hole 40,
The poles 37, 37 are in sliding contact with 0a, and this pole 3
7 and 37 are tilted in the direction in which they are separated from the ratchet 36, that is, in the direction in which the meshing engagement is released.
Moreover, in this case, the ends of the engagement holes 40, 40 abut on the pawls 37, 37, so the plate 39 rotates together with the complete 34 via the pawls 37, 37, and therefore the pawl 3
7 and 37 remain pressed by the cam 40a, and are held in a position separated from the ratchet 36.

Furthermore, when the rotational speed of the crankshaft 13 and the driven shaft 28 increases and the clutch plate 42 of the centrifugal clutch 41 reaches a rotational speed higher than a predetermined value, the third speed gear 48 is transferred via the clutch housing 45 by the action of a clutch weight (not shown). and driven shaft 28
are connected and rotate as one. The third speed gear 48 meshes with the primary gear 14, and the mutual reduction ratios of the third speed gear 48 and the primary gear 14 are set smaller than the mutual reduction ratios of the second output gear 21 and the second speed gear 30. Therefore, the clutch housing 45 is rotated before the clutch weight 24 of the second output gear 21. Therefore, the rotational force of the crankshaft 13 is transmitted to the driven shaft 28 via the primary gear 14 and the third speed gear 48, and the reduction ratio of the driven shaft 28 is reduced to shift up to the third speed. In this case, the rotational force of the second gear 30 is the same as that of the first gear 2.
Similarly to 9, the transmission is not transmitted to the driven shaft 28 via the one-way clutch 12 on the second gear 30 side, and each pawl 37 of this one-way clutch 12 is inserted into the engagement hole 40 of the plate 39 in a direction that does not engage the ratchet 36. , 40.

According to one embodiment relating to such an operation, each of the one-way clutches 12 is connected to the first gear 29 and the second gear.
When the rotational force of the speed gear 30 is not transmitted to the driven shaft 28, the respective pawls 37, 37 of the one-way clutch 12 are tilted down by the engaging holes 40, 40 of the plate 39 in a direction that does not contact the ratchet 36. Because of this, each of the pawls 37 does not come into contact with the ratchet 36. Therefore, the tip of each pawl 37 does not rotate following the shape of the ratchet 36, and the tip is not struck by the ratchet 36, so that the above-mentioned repetitive movement of each pawl 37 can be eliminated. Therefore, the proximal end of each pawl 37 is not repeatedly worn against the boss one-way complete 34, so that each pawl 37 is not damaged by this wear. Also,
Due to the elimination of the above-mentioned repetitive motion, no repeated load is applied to the pawl springs 38 that urge each of the pawls 37 in the direction of engagement with the ratchet 36, and the springs 38 are not damaged by this repeated load. Nor.

Furthermore, since the repetitive motion is eliminated, the tips of the pawls 37 are not hit by the ratchet 36, so the tips do not wear out, and the noise generated between the pawls 37 and the ratchet 36 is prevented. can be prevented.

Further, the one-way clutch described above is not only used in automatic transmissions of motorcycles, but can be similarly implemented in automatic transmissions of other vehicles. Further, the engine is not limited to a 2-stroke engine, but may be a 4-stroke engine.

According to the present invention described in detail above, when the rotating body or rotating wheel is rotated in a direction in which the pawl and the ratchet do not engage, the pawl in the engaging hole is moved by the cam formed at the opening periphery of the engaging hole. Since it is pressed in a direction away from the ratchet, the tip of the pawl does not rotate to follow the shape of the ratchet, and this repetitive movement of the pawl can be eliminated. Therefore, when the pawl is not engaged with the ratchet, the pawl will not be continuously struck by the ratchet, which will prevent the pawl from being worn out and damage caused by this abrasion, and will also reduce the noise generated between the ratchet and the pawl. It has the advantage of being preventable.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a side view of a two-wheeled motor vehicle, Fig. 2 is a cross-sectional view showing a part of the crankcase, and Figs. 3 and 4 are cross-sectional views of a one-way clutch. Figure 2 is a front view as seen from direction Q, Figure 5 is a front view of the one-way clutch body, Figure 6 is a front view of the contact release member, Figure 7 is a longitudinal sectional view of the contact release member, and Figure 8 is a front view of the one-way clutch body. Enlarged sectional view in Figure 3, No. 9
The figure is an enlarged sectional view of FIG. 28... Driven shaft (rotating shaft), 34... Boss one-way complete (rotating body), 35... Sleeve (rotating wheel body), 36... Ratchet, 37...
Paul, 39...Plate, 40...Hatching hole, 4
0a...cam.

Claims (1)

[Scope of Claims] 1. A rotating body that rotates together with a rotating shaft and a rotating wheel that covers the outer periphery of the rotating body are provided so as to be relatively rotatable, and the outer peripheral surface of these rotating bodies and the inner periphery of the rotating wheel are relatively rotatable. While forming a ratchet on either side of the surface,
A one-way clutch is provided with a pawl that is always biased in the direction of engagement with the ratchet, and the engagement between the ratchet and the pawl causes the rotating body and the rotating wheel to integrally rotate in only one direction. , A plate that is rotatable with the rotating body and the rotating wheel is pressed into contact with the side surfaces of the rotating body and the rotating wheel, and an engagement hole is formed in this plate into which the pawl is fitted with play, and The opening periphery of the engagement hole is provided with a ring that, when the rotating body or rotating wheel is rotated in a direction in which it slides into contact with the pawl and the pawl and the ratchet do not mesh with each other,
A one-way clutch comprising a cam that presses the pawl away from the ratchet.