JPH04362341A - V-belt transmission for motorcycle - Google Patents

Abstract

PURPOSE:To heighten the power transmission efficiency of a V-belt transmission for a motorcycle and prolong the life of a V-belt. CONSTITUTION:The oscillating ends of linkage bars 20, 23 are connected to the driving faces 11a, 11b of a driving pulley 11 and the driven faces 12a, 12b of a driven pulley 12. The linkage bars 20, 23 are formed to be laterally oscillated by pivots 26, 27 positioned between both pulleys 11, 12, and a step motor 33 is provided to freely separate the oscillating ends of both linkage bars 20, 23. A V-belt 13 is not therefore clamped by the driven pulley 12 with spring force, so that the minimum required frictional force for power transmission acts upon the V-belt 13.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a V-belt transmission used in a motorcycle, and more particularly to the structure of the transmission mechanism.

0002

[Prior Art] Conventional V-belt transmissions for motorcycles are
The movable faces of the driving pulley on the engine side and the driven pulley on the rear wheel side are moved in the axial direction by a moving mechanism to change the winding diameter of the V-belt. In the moving mechanism, the driving pulley is powered by the centrifugal force of a centrifugal ball rotating together with the driving pulley, and the driven pulley is powered by the elastic force of a compression coil spring, and the driving pulley receives a large force from the centrifugal ball. Accordingly, the movable face approaches the fixed face and the V-belt wrap diameter becomes larger. Further, the movable face of the driven pulley is always biased by a compression coil spring so that the V-belt wrap diameter increases as the movable face approaches the fixed face.

In the conventional V-belt transmission for motorcycles configured as described above, when the engine speed is low and the centrifugal force of the centrifugal ball is relatively small, the winding diameter of the V-belt on the driven pulley is smaller than that on the drive pulley. It becomes larger than the winding diameter of. At this time, the reduction ratio increases and the rear wheel connected to the driven pulley rotates at a low speed. When the engine rotates at high speeds, the centrifugal force increases and the diameter of the V-belt wrapped around the drive pulley increases.As a reaction to this, the diameter of the V-belt wrapped around the driven pulley decreases, causing the rear wheels to rotate at high speed. It turns out. At this time, the movable face of the driven pulley moves away from the fixed face against the elastic force of the compression coil spring. That is, in the conventional V-belt transmission, the V-belt rotates while being always sandwiched between the fixed face and movable face of the drive pulley and the fixed face and movable face of the driven pulley.

0004

[Problems to be Solved by the Invention] However, in this structure in which the V-belt is rotated while being constantly pressed between the fixed face and the movable face, the frictional force acting on the V-belt is reduced to the minimum required for power transmission. The frictional force becomes larger than the required one. As a result, the power transmission efficiency of the V-belt transmission is reduced, and the life of the V-belt is shortened.

[0005]

[Means for Solving the Problems] A V-belt transmission for a motorcycle according to the present invention has a moving mechanism for operating a movable face that is formed long in the direction in which a driving pulley and a driven pulley are arranged side by side, so that the moving mechanism for operating a movable face is formed long in the direction in which a driving pulley and a driven pulley are arranged side by side. Consisting of an interlocking bar provided to be swingable in the left-right direction by a support shaft located on the side and located approximately in the middle between both pulleys, and a drive means for rotating the interlocking bar about the support shaft, One end of the interlocking bar is connected to a movable face of a driving pulley, and the other end is connected to a movable face of a driven pulley.

[0006]

[Operation] By rotating the interlocking bar, the movable faces of the driving pulley and the driven pulley move in opposite directions along the axial direction. The winding diameter of the V-belt changes and the speed changes.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be explained in detail below with reference to FIGS. 1 to 5. FIG. 1 is a side view of a motorcycle equipped with a V-belt transmission according to the present invention, FIG. 2 is a side view of an engine equipped with a V-belt transmission according to the present invention, and FIG. 3 is a side view of a crankcase in FIG. 2. FIG. 4 is an enlarged plan view showing the V-belt transmission according to the present invention, and FIG. 5 is an enlarged side view showing the V-belt transmission according to the present invention. In these figures, 1 is a motorcycle, and 2 is an engine of this motorcycle 1. This engine 2 is a two-stroke, single-cylinder engine that includes a crankcase 2a and a cylinder 2b. 3 is the rear wheel of this motorcycle 1; 4 is the crankcase 2 of the engine 2;
This crankshaft 4 is connected to an output shaft 8 via a V-belt transmission 5, a centrifugal multi-disc clutch 6, and a planetary gear reducer 7, which will be described later. The crankshaft 4 is configured to rotate clockwise when viewed from the right side of the engine 2, as shown by the arrow in FIG.

The V-belt transmission 5 is disposed on the right side of the engine 2, and is configured with the crankshaft 4 as a driving shaft. 10 is a driven shaft, and this driven shaft 10 is provided parallel to the crankshaft 4 on the rear side of the crankshaft 4, and has a bearing on the crankcase 2a and the transmission casing 5a attached to the right side of the crankcase 2a. It is rotatably supported via. A clutch drum of a centrifugal multi-disc clutch 6, which will be described later, is connected to the end of the driven shaft 10 on the engine center side. A driving pulley 11 is mounted on the crankshaft 4, and a driven pulley 12 is mounted on the driven shaft 10, and an elastic V-belt 13 made of rubber is wound around these pulleys. The driving force of the crankshaft 4 is sequentially applied to the drive pulley 11, V-belt 13, driven pulley 12, centrifugal multi-disc clutch 6, planetary gear reducer 7,
The power is transmitted to the rear wheels 3 via a rear wheel drive chain 3a or the like.

The driving pulley 11 has a pair of left and right driving faces 11a and 11b forming a V-belt groove 14,
Each of the drive faces 11a, 11b is spline-fitted to the crankshaft 4 so as to be slidable in the axial direction, and both are movable faces. Further, the driven pulley 12
is a pair of left and right driven faces 1 forming a V-belt groove 15
2a, 12b, each driven pulley 12a, 12b
is spline-fitted to the driven shaft 10 so as to be slidable in the axial direction, and both have movable faces.

Front brackets 17a, 17b are supported on each of the drive faces 11a, 11b via bearings 16, while rear brackets 19a, 19b are supported on each driven face 12a, 12b via bearings 18. There is. 20, 20 are the upper and lower interlocking bars on the right side, each interlocking bar 20
The front end 20a, which is a pivoting end on one end, is pivoted to the right front bracket 17a by a pivot pin 21, and the rear end 20b, which is a pivoting end on the other end, is pivoted to the right rear bracket 19a by a pivot pin 22. supported. Further, reference numerals 23 and 23 denote upper and lower interlocking bars on the left side, and the front end 23a, which is one rotating end of each interlocking bar 23, is pivoted to the left front bracket 17b by a pivot pin 24, and the other end side is pivoted. The rear end 23b is pivotally supported by a pivot pin 25 on the left rear bracket 19b.

At approximately the midpoint in the longitudinal direction of the driving pulley 11 and the driven pulley 12, the upper and lower interlocking bars 20, 20 on the right side
A right pivot shaft 26 is rotatably supported around its vertical axis. In addition, the same drive pulley 11 and driven pulley 1
At approximately the midpoint in the longitudinal direction of 2, the left upper and lower interlocking bars 23
, 23, a left pivot shaft 27 is rotatably supported around its vertical axis. The left and right pivot shafts 26, 2
7 are connected to each other by a connecting shaft 28. A tension pulley 29 is attached to the connecting shaft 28. By the way, the crankshaft 4 and the drive pulley 11
rotates in the direction shown by arrow A in FIG. 5, and therefore, the driven shaft 10 and driven pulley 12 rotate in the direction shown by arrow B in FIG. 5 via the V-belt 13. Then, the tension pulley 29 biases the loose side of the V-belt 13 and
Apply tensile force to 3. That is, the tension pulley 29
is an eccentric disk 29 mounted eccentrically with respect to the connecting shaft 28;
a, and a bearing 29b is provided on the outer peripheral surface of this eccentric disk 29a.
An annular rolling pressing body 29c is supported via the ring. Further, a spring 30 is provided that presses the V-belt 13 against a portion that protrudes more radially from the connecting shaft 28 . As a result, the V-belt 13 comes into pressure contact with the driving pulley 11 and the driven pulley 12 and frictionally engages them.
Power is transmitted from the driving pulley 11 side to the driven pulley 12 side.

The left and right interlocking bars 20 and 23 are connected to the pivot shaft 2.
Driving means 32 for rotating around 6 and 27 is provided. This drive means 32 has a step motor 33 attached to the transmission casing 5a, and has a screw shaft 35 integrally formed with an output shaft 34 of this step motor 33. This screw shaft 35 has a pair of left and right screws 36a, 36.
The screw 36a on the right side is a left-hand screw, and the screw 36b on the left side is a right-hand screw. In addition, each screw 36a, 3
Nuts 37a and 37b are screwed onto 6b. On the other hand, at the front ends of the lower interlocking bars 20 and 23, as shown in FIG.
38b is integrally molded, and each extension bar 38a, 38
The front end of b is pivoted to the nuts 37a and 37b by left and right pivot pins 39 and 40, respectively. Note that 41 is a lead wire of the step motor 33.

The centrifugal multi-disc clutch 6 has the driven shaft 1
A centrifugal ball 6b, a clutch plate 6c, etc. are built into a clutch drum 6a that is integrally provided in the clutch drum 6a, and when the rotational speed of the clutch drum 6a exceeds a predetermined value, power is transferred from the clutch drum 6a to the clutch output shaft 6d. configured to communicate. Note that 6e is a push rod for forced clutch release, one end of which is connected to the clutch plate side, and the other end engaged with a cam 6f for clutch operation. Further, the clutch output shaft 6d has a sun gear of a planetary gear reducer 7 formed at its end, and is connected to the output shaft 8 via a planetary gear 7a. Note that 7b is an internal gear of the planetary gear reducer 7, and is fixed to the crankcase 2a. That is, when the driven shaft 10 of the V-belt transmission 5 rotates at high speed, the power of the engine 2 is transmitted from the V-belt transmission 5 to the output shaft 8 via the centrifugal multi-plate clutch 6 and the planetary gear reducer 7. 51 is a rear wheel drive sprocket connected to the output shaft 8, and a rear wheel drive chain 3a is wound around this sprocket 51. A kickstarter lever 52 is attached to the left side of the crankcase 2a, and is configured to rotate a driven gear 53 at the left end of the crankshaft 4 by a drive gear 54.

In the V-belt transmission 5 configured as described above, by swinging the interlocking bars 20 and 23 about the pivot shafts 26 and 27, respectively, the drive faces 11a and 11b of the drive pulley 11 and the driven The driven faces 12a and 12b of the pulley 12 can be moved simultaneously in the axial direction to change speed. The operation will be explained in detail below. When the V-belt transmission 5 decelerates the power transmitted from the crankshaft 4 side to the driven shaft 10 side, the step motor 33 is driven to rotate the screw shaft 35 in the direction of arrow C in the figure. Then, as each nut 37a, 37b moves, both the extending bars 38a, 38b are rotated around the pivot shafts 26, 27 from the state shown by the solid line in FIG. The driving faces 11a and 11b connected to the front ends 20a and 23a of the interlocking bars 20 and 23 are separated from each other to reduce the winding diameter of the V-belt 13 on the driving pulley 11. Then, as a reaction to this, the driven faces 12a, 12b connected to the rear ends 20b, 23b of the interlocking bars 20, 23 approach each other. That is,
The winding diameter of the driven pulley 12 with the V-belt 13 increases, resulting in deceleration. On the other hand, when increasing the speed, the step motor 33 is driven in the opposite manner to the above,
Rotate the screw shaft 35 in the direction opposite to the arrow C in the figure. As each nut 37a, 37b moves thereby, both extending levers 38a, 38b are rotated around the pivot shafts 26, 27 from the state shown by the imaginary line in FIG. , 23 are brought closer to each other to increase the winding diameter of the V-belt 13 on the drive pulley 11. Then, as a reaction to this, the same interlocking bar 20,
Driven face 1 connected to rear ends 20b, 23b of 23
2a and 12b are spaced apart from each other, and the diameter of the V-belt 13 wound around the driven pulley 12 becomes smaller. Therefore, the speed will be increased.

In the V-belt transmission 5 configured as described above, the width dimension of the V-belt groove in the drive pulley 11 and the driven pulley 12 is automatically determined according to the amount of rotation of the interlocking bars 20 and 23. become. Therefore, unlike the conventional case, the V-belt 13 is not pinched by the driven pulley due to the elastic force of the spring, so the V-belt transmission 5
When the V-belt 13 is in a no-load state, the V-belt 13 is connected to the drive pulley 1.
1 and the driven pulley 12 with a light frictional force.

Although the above is based on the illustrated example, each of the pivot shafts 26 and 27 may be fixed to the transmission casing 5a. Further, each of the interlocking bars 20 and 23 may be one of the upper and lower interlocking bars, or only one of the left and right interlocking bars 20 and 23 may be provided. Furthermore, although this embodiment shows an example in which the V-belt transmission 5 is mounted on a two-stroke single-cylinder engine 2, it can be mounted on a four-stroke four-cylinder engine as shown in FIGS. 6 and 7, and as shown in FIGS. 8 to 10. It can also be installed in a unit swing type engine.

FIG. 6 is a side view showing another embodiment in which the V-belt transmission according to the present invention is mounted on a four-cycle four-cylinder engine, FIG. 7 is a sectional view taken along line VII-VII of the engine in FIG. 6, and FIG. A side view showing another embodiment in which the V-belt transmission according to the present invention is mounted on a unit swing engine of a scooter, FIG. 9 is a sectional view taken along the line IX-IX in FIG. 8, and FIG. 10 is a V-belt transmission in FIG. 9. FIG. In these figures, the same or equivalent members as those explained in FIGS. 1 to 5 are given the same reference numerals and detailed explanations will be omitted. 6 and 7, 61 is a 4-cycle, 4-cylinder engine for a motorcycle, and 62 is a crankshaft supported by a crankcase 61a of the engine 61. In FIG. Reference numeral 63 denotes a conventionally known multi-plate clutch, in which the rotation of the crankshaft 62 is transmitted while being decelerated by a chain 64, and the clutch output shaft 65 is used as the drive shaft of the V-belt transmission 5. Note that 66 is a push rod for releasing the clutch. The V-belt transmission 5 used in this embodiment is located near the center in the width direction of the engine 61, and the driving means for rotating the interlocking bars 20 and 23 is arranged on the driven pulley 12 side (rear side). . A rear wheel drive sprocket 51 is attached to the shaft end of the driven shaft 10. 8 to 10, 71 is a scooter, 72 is a unit swing type engine of the scooter 71, and 73 is a crankshaft. In this embodiment, the drive pulley 11 of the V-belt transmission 5 is mounted on the shaft end of the crankshaft 73. In the V-belt transmission 5 shown in this example, the interlocking bars 20 and 23 are connected to the step motor 33 via front and rear wires 74 and 75. The operating side ends of the wires 74 and 75 are connected to the upper interlocking bars 20 and 23, and the motor side ends are connected to a pulley 76 of the step motor 33. In addition, the outer end of each wire on the operating side is attached to the interlocking bar 20 on the right side.
The inners are respectively locked to the left interlocking bar 23. That is, in this V-belt transmission 5, the speed is increased by driving the step motor 33 and pulling the inner side of the front wire 74, and the speed is reduced by pulling the inner side of the rear side wire 75. Note that the step motor 33
is fixed to a vehicle body frame (not shown) within the vehicle body cover 71a of the scooter 71. Further, in this embodiment, the tension pulley 29 has a pair of faces forming a V-belt groove, and has a structure in which one face is biased toward the other face side by a compression coil spring 76. and the loose side are biased by both faces. Note that 77 indicates a centrifugal clutch for rear wheel drive, and its input shaft 78 is connected to the driven pulley 12.
It is configured to be driven by. The output shaft 79 of the centrifugal clutch 77 passes through the axial center of the driven pulley 12 and is connected to a rear wheel shaft 81 via a planetary gear reducer 80. 4 cycles 4 as described above
Even if the V-belt transmission 5 is mounted on the cylinder engine 61 or the unit swing type engine 72, the same effects as the embodiments shown in FIGS. 1 to 5 can be obtained.

[0018]

As explained above, in the V-belt transmission for motorcycles according to the present invention, the moving mechanism for operating the movable face is formed long in the direction in which the drive pulley and the driven pulley are arranged side by side, and It is composed of an interlocking bar that is provided on the end side and is swingable in the left-right direction by a support shaft located approximately in the middle between both pulleys, and a drive means that rotates the interlocking bar about the support shaft. , one end of the interlocking bar is connected to the movable face of the driving pulley and the other end is connected to the movable face of the driven pulley, so that by rotating the interlocking bar, the movable faces of the driving pulley and the driven pulley are Since the V-belts move in opposite directions along the direction, the winding diameter of the V-belt on the drive pulley and the driven pulley changes according to the swinging operation of the interlocking bar, thereby changing the speed. For this reason, as in the conventional case, V
Since the belt is not pinched by the driven pulley, when the V-belt transmission is under no load, the V
The belt comes into contact with the driving pulley and the driven pulley with a light frictional force. Therefore, since the minimum necessary frictional force for power transmission acts on the V-belt, the power transmission efficiency can be increased and the life of the V-belt can be extended.

[Brief explanation of drawings]

FIG. 1 is a side view of a motorcycle equipped with a V-belt transmission according to the present invention.

FIG. 2 is a side view of an engine equipped with a V-belt transmission according to the present invention.

FIG. 3 is a sectional view taken along line III-III of the engine in FIG. 2;

FIG. 4 is a plan view showing an enlarged V-belt transmission according to the present invention.

FIG. 5 is an enlarged side view of the V-belt transmission according to the present invention.

FIG. 6 is a side view showing another embodiment in which the V-belt transmission according to the present invention is mounted on a 4-stroke, 4-cylinder engine.

7 is a sectional view taken along the line VII-VII of the engine in FIG. 6. FIG.

FIG. 8 is a side view showing another embodiment in which the V-belt transmission according to the present invention is mounted on a unit swing type engine of a scooter.

9 is a sectional view taken along the line IX-IX in FIG. 8. FIG.

10 is a view taken along arrow A of the V-belt transmission in FIG. 9. FIG.

[Explanation of symbols]

1 2-stroke single-cylinder engine 3 Rear wheel 4 Crankshaft 11 Drive pulley 11a Drive face 11b Drive face 12 Driven pulley 12a Driven face 12b Driven face 13 V-belt 20 Interlocking bar 23 Interlocking bar 26 Pivot axis 27 Pivot axis 33 Step motor 35 Screw shaft

Claims (1)

[Claims] 1. A V-belt is wound around a drive pulley driven by an engine and a driven pulley connected to a rear wheel, and at least one of a pair of faces forming a V-belt groove of each pulley is wound around a drive pulley driven by an engine and a driven pulley connected to a rear wheel. , a V-belt transmission for a motorcycle having a movable face that is moved in the axial direction by a moving mechanism, wherein the moving mechanism is formed long in the direction in which both the pulleys are arranged side by side and is disposed on the shaft end side of both the pulleys; It consists of an interlocking bar that is swingable in the left-right direction by a support shaft located approximately in the middle between both pulleys, and a drive means that rotates the interlocking bar about the support shaft, one end of the interlocking bar. A V-belt transmission for a motorcycle, characterized in that one end is connected to a movable face of a driving pulley, and the other end is connected to a movable face of a driven pulley.