JPH026296Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Field of Industrial Application) This invention relates to a belt-type automatic transmission that is added with a function of controlling the reduction ratio according to the magnitude of the load.

(Prior Art) As shown in Fig. 4, a two-wheeled motor vehicle has a transmission system from an engine crankshaft 1 to a rear wheel 2 integrated into a power unit, and a V-belt continuously variable transmission device is incorporated therein. There is. The crankshaft 1 protrudes into a belt chamber 5 in a swing case 4 connected rearward from the crank case 3, and a drive V pulley 6 of a V belt transmission mechanism is mounted thereon, and a driven shaft 7 is mounted on the rear of the swing case. upper driven V
A V-belt 9 is suspended between the pulley 8 and the pulley 8. The rotation of the driven V pulley 8 is transmitted to the driven shaft 7 via the starting clutch 10, which projects into the gear chamber 11 and transmits the rotation to the rear wheel 2 via the reduction gear train 12.

The drive V pulley 6 is composed of a fixed face 6a and a movable face 6b that rotates integrally with the crankshaft 1 and is slidable in the axial direction.The movable face 6b is rotated by a centrifugal roller 13 provided behind it. It moves toward the fixed face 6a according to the number of V
The effective diameter of the suspension of the belt 9 is increased.

The driven V pulley 8 also has a fixed face 8a,
It is composed of a movable face 8b with a spring 14 loaded behind it, and as the effective diameter of the drive V pulley 6 increases, the effective diameter follows and decreases, resulting in an overall reduction in the reduction ratio. ing.

The driven V pulley 8 further has a fixed face 8.
As shown in FIGS. 5 and 6, the movable face 8b is engaged with the roller 15 through an axial long hole 16 inclined in the circumferential direction, and the thrust direction portion of the transmitted torque is Movable face 8b by force
The structure is such that the speed reduction ratio is increased by bringing the speed reduction ratio closer to the fixed face 8a. Some use threaded splines or cams to generate this thrust force.

However, this thrust force is generated by 1/2 of the transmitted torque, and the fixed face 8a and the movable face 8
It is necessary to rotate relative to b. Therefore, there is no effect unless a torque sufficient to cause the V-belt to slip, that is, a load torque of at least 1/2 or more of the allowable transmission torque is applied. Furthermore, due to the relative rotation of both faces 8a and 8b, the durability of the V-belt is reduced and power loss occurs. During steady high-speed operation, the stored force of the spring 14 increases, resulting in excessive thrust force, which greatly affects the V-belt durability and power transmission rate.

(Problem to be solved by the invention) Taking the above points into consideration, this invention prevents relative rotation between the fixed face and the movable face, and uses the thrust force of the load torque to drive the driven V pulley. An object of the present invention is to provide a belt type automatic transmission device that can control the effective diameter of the belt.

[Structure of the idea]

(Means for Solving the Problems) With the above object, the belt type automatic transmission of this invention has a drive V pulley mounted on a drive shaft and a driven V pulley mounted on a driven shaft. The drive V pulley is a device that transmits power by suspending a belt, and the drive V pulley is rotatably supported coaxially with a fixed face fixed to the drive shaft so as to be slidable in the axial direction. A movable face that is pressed against a fixed face by a force is provided oppositely to the driven V pulley. Similarly, a fixed face and a movable face are provided oppositely to each other, and the fixed face is rotatably attached to the driven shaft and is immovable in the axial direction. A roller supported by a diametrical support shaft is disposed on the outer surface of the shaft hole boss of the movable face, and a movable face has an elongated hole in the axial direction in its shaft hole boss, and this movable face shaft hole boss is fixed. By being aligned on the face shaft hole boss and engaging the roller in the long hole,
Both faces are rotatably combined so as to be freely slidable in the axial direction, and the movable face is pressed against the fixed face by a spring, and an axially inclined surface formed on the end face of the shaft hole boss of the movable face and the driven shaft is formed. The inclined surface is engaged as a torque transmission surface.

(Function) With this structure, the V-belt suspension diameter of the drive V-pulley increases in accordance with the rotation speed of the drive shaft, and in response to this, the V-belt suspension on the driven V-pulley side is balanced with the force of the spring. By reducing the diameter, the reduction ratio decreases (speed increase).

At the same time, in the driven V pulley, torque is transmitted from the movable face to the driven shaft via the inclined surface, and the axial component of the transmitted torque is added to the force of the spring, thereby resisting reduction in the V-belt suspension diameter. Therefore, the larger the load torque is, the more the speed increase is suppressed and the transmission is conducted at a larger reduction ratio. That is, the reduction ratio is controlled according to the rotation speed of the drive shaft and the magnitude of the load.

The fixed face and movable face of the driven V-pulley have no relative displacement in the rotational direction, and no slipping occurs on one side of the suspended V-belt, so mechanical loss is small and the entire torque transmitted from the driven V-pulley to the driven shaft is reduced in the axial direction. A component force is applied to the movable face to stabilize this deceleration control. Since the fixed face and the movable face are connected by rollers provided in the respective shaft hole bosses and an elongated hole in the axial direction, the movement is smooth and the structure is compact.

(Embodiment) FIG. 1 is a longitudinal sectional view of a driven V pulley showing an embodiment of this invention.

A fixed face 8a of the driven V pulley 8 is supported on the driven shaft 7 so as to be rotatable but not slidable in the axial direction. A shaft hole boss 17b of the movable face 8b is pivotally supported by this shaft hole boss 17a. Fixed face 8a
A roller 18, which is rotatably supported by a diametrical support shaft on the outer surface of the shaft hole boss 17a, is fitted into an axial long hole 19 of the movable face shaft hole boss 17b, and the movable face 8b rotates integrally with the fixed face 8a. are connected so that they can freely slide in the axial direction. And movable face 8b
A chevron-shaped cam 20 is formed on the end face. On the other hand, a chevron-shaped cam 24 provided on the end surface of the shaft hole boss 23 of the drive plate 22 to which the centrifugal shoe 21 of the starting clutch 10 is attached engages with the cam 20. The driven drum 25 of the starting clutch 10 is connected to the driven shaft 7.

With the above configuration, the rotation transmitted to the driven V pulley 8 by the V belt 9 is transmitted to the chevron cam 20,
24, the signal is transmitted to the starting clutch 10, the driven shaft 7, and finally to the rear wheel 2.

The effective diameter of the driven V pulley 8 with respect to the V belt 9 is determined by the action of the drive V pulley 6 to open the movable face 8b with the tensile force generated by expanding the V belt suspension diameter by centrifugal force, and the angle-shaped cam 20 of the transmission torque. The thrust force caused by 24 moves the movable face 8
It is determined by the balance with the action of compressing b (the force of the spring 14 is applied). Therefore, when the load is large and the transmitted torque is large, the effective diameter of the drive V pulley 6 increases, and the reduction ratio increases to correspond to the load.

Both the fixed and movable faces 8a and 8b of the driven V pulley 8 directly drive the driven V by the thrust force of the entire transmitted torque without relative rotation.
Since the pulley 8 is controlled, it operates at an extremely effective reduction ratio in balance with the control based on the rotation speed of the drive V pulley 6 side, improving the function as an automatic transmission. Therefore, the force of the spring 14 can be set small, no excessive thrust force is generated during high-speed steady operation, and in combination with the absence of relative rotation between the two faces, the durability of the V-pulley 9 is improved and power loss is reduced. Reduce.

[Effect of the invention] As described above, in the belt-type automatic transmission according to the invention, the fixed face and the movable face of the driven V pulley are rotated together in the axial direction by the rollers and the axial elongated holes provided in the respective shaft hole bosses. It is slidably connected and transmits torque between the movable face shaft hole boss end face and the load side shaft end on an inclined surface where thrust force acts.The reduction ratio is controlled according to the magnitude of the load, and the speed is In addition to making the action more flexible, there is no power transmission loss especially in low-torque operation, which increases fuel consumption, and by making the device more compact, costs can be reduced.
This prevents wear on the V-belt due to relative slippage between both pulley faces, increasing the durability of the V-belt, etc.
It has great effects when used in the conduction system of small motorcycles, etc.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional side view of a driven V pulley showing an embodiment of this invention, Fig. 2 is an end view of a movable face shaft hole boss used in the driven V pulley shown in Fig. 1, and Fig. 3 is a movable face shown in Fig. 2. Figure 4 is an exploded view of the face shaft hole boss, Figure 4 is a cross-sectional plan view of a motorcycle transmission system showing an example of a conventional V-belt automatic transmission, and Figure 5 is a cross-sectional plan view of the transmission system of a two-wheeled motor vehicle.
Figure A-A arrow enlarged sectional view, Figure 6 is Figure 5 B-B
It is an arrow sectional view. 6... Drive V pulley, 6a... Fixed face, 6b... Movable face, 8... Driven V pulley, 8a... Fixed face, 8b... Movable face, 9... V belt, 10... Starting clutch,
17a... Fixed face shaft hole boss, 17b... Movable face shaft hole boss, 18... Roller, 19...
Long hole, 20, 24... chevron cam.

Claims (1)

[Scope of utility model registration request] A drive V pulley mounted on the drive shaft,
Driven V pulley mounted on the driven shaft
The drive V pulley is a device that transmits power by suspending a belt, and the drive V pulley is rotatably supported coaxially with a fixed face fixed to the drive shaft so as to be slidable in the axial direction. A movable face that is pressed against a fixed face by a force is provided oppositely to the driven V pulley. Similarly, a fixed face and a movable face are provided oppositely to each other. A roller supported by a diametrical support shaft is disposed on the outer surface of the shaft hole boss of the movable face, and the movable face has an elongated hole in the axial direction in its shaft hole boss, and this movable face shaft hole boss is fixed. By aligning the faces onto the shaft hole bosses and engaging the rollers in the elongated holes, both faces are rotated integrally and slidably in the axial direction, and the movable face is pressed against the fixed face by the spring. A belt-type automatic transmission, characterized in that an axially inclined surface formed on a movable face shaft hole boss end surface and an inclined surface formed on a driven shaft are engaged as a torque transmission surface.