JPS60136653A - V-belt type automatic transmission unit - Google Patents

Abstract

PURPOSE:To obtain a V-belt type automatic transmission unit which can offer powerfull drive upon climbing of a sloping road, etc., by providing, on the primary sheave side, a control mechanism for shifting a movable pulley, overcoming the thrust force of a flyweight, in association with external control operation. CONSTITUTION:There is provided a control mechanism 60 which increases a drive force, on the primary sheave 36 side. When the left grip 5 of a steering handle 4 is rotated, a lever 71 is pulled to rotate a press-actuating element 67, and at this time the press-actuating element 67 is shifted to the right to engage both screw splines 68, 70 with each other. The press-actuating element 67 urges a spring 66 so that a press dog is moved rightward, and therefore, the arms 62, 63 of the dog 61 press a movable pulley 40 rightward to force a V-shape groove 41 into enlargement.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a V-belt automatic transmission used in small vehicles such as motorcycles.

[Technical background of the invention]

V-belt automatic transmissions, which are often used in scooter-type motorcycles, have a primary sheep on the drive shaft, such as the crankshaft, which is rotated by the power of the engine.
A secondary sheep is provided on the output shaft on the rear wheel side, and a V-belt is passed between the primary sheep and the secondary sheep. The primary sheave and secondary sheave each form a V-shaped groove with a fixed pulley and a movable pulley, and when the engine speed increases, the movable pulley on the primary sheave side receives thrust due to the centrifugal force of the flyweight. This reduces the width of the V-groove on the primary sheep side, increasing the contact radius of the V-belt, and accordingly, the secondary sheep increases the width of the V-groove and increases the contact radius of the V-belt. Since the speed decreases, the gears are automatically changed.

[Problems with background technology]

In the past, this glazed V-belt automatic transmission was designed to operate at a low engine speed in order to reduce noise and save fuel consumption, and therefore the fifth factor - vehicle speed - engine speed. As shown by solid line A in the characteristic diagram, the gear ratio was set to decrease quickly when the engine speed was relatively low. However, with these characteristics, there was a problem that the powerful running, such as pitching ability, was sacrificed.

[Purpose of the invention]

, the present invention was made based on these circumstances,
The purpose of the present invention is to provide a V-belt automatic transmission that can perform low-noise and fuel-efficient operation similar to conventional transmissions, and can also switch its shifting characteristics so that powerful operation can be performed when pitching or the like.

[Summary of the invention]

The present invention is provided with an operating mechanism on the primary sheep side that is operated by external operation against the thrust of the seven flyweights of the movable pulley of the primary sheep. The feature is that by pushing in the direction and forcibly widening the 7-shaped groove, the gear ratio can be increased when the engine speed is high, increasing the pitching ability.

[Embodiments of the invention]

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

Figure 1 shows a scooter-type motorcycle, where 1 is a frame;
2 is the front fork, 3 is the front wheel, 4 is the steering handle,
Reference numeral 5 indicates a left grip on the steering wheel, 6 indicates a leg shield, 7 indicates a seat, and 8 indicates a cover. A front end portion of an engine unit 10 is swingably supported by a pivot 11 on a rear rising portion 9 of the frame 1 . The rear end of the engine unit 10 is suspended from the frame 1 by a shock absorber 12.

13 is the rear wheel.

The engine unit 10 is shown in cross section in Figure 2, and will be described below. Reference numeral 15 designates a two-stroke engine, and its crankcase 16 is divided into left and right halves by abutting a right case 17 and a left case 18. The crankcase 16 is provided with a cylinder block 19 and a cylinder head 20. Sylinta Buyok 1
A piston 21 in 9 is connected to a crankshaft 23 via a connecting rod 22.

The crankshaft 23 corresponds to the drive shaft of the present invention, and is supported by bearings 24, 24 on the crankshaft 216. A generator 25 and a fan 26 are attached to the right end of the crankshaft 23. The fan 26 introduces outside air from the intake port 28 into the air shroud 27 that covers the cylinder block 19 and the cylinder head 20 gold.
5 is forcibly cooled.

A transmission case 11O extending rearward is integrally formed with the left case 18, and this transmission case 30 is covered by a transmission case cover 31. The output shaft 32 is connected to the bearing 3 at the rear end of the transmission case 3O and the transmission case cuckoo 31.
3 and 33. This output shaft 32 is parallel to the crankshaft 23, and these crankshafts 2
A V-belt automatic transmission 35 is provided between the output shaft 32 and the output shaft 32 .

To explain the V-belt automatic transmission 35, 36 is a primary sheep on the crankshaft 23 side, 37 is a secondary sheep on the output shaft 32 side, and 38 is a V-belt. The primary sheep 3O is formed by forming a V-shaped groove 41 between a fixed pulley 39 and a movable boot 1J40, and the fixed pulley 39 is spline engaged with the crankshaft 23, and the movable pulley 4O is connected to the crankshaft 23 through a collar 42. It is attached to the crankshaft 23 so as to be movable in the axial direction. A flyweight 44 is provided between the support plate 43 fixed to the crankshaft 23 and the movable pulley 4O, and the flyweight 44 is moved in the outer radial direction by generating centrifugal force by the crankshaft 230 rotations. . When the flyweight 44 moves in the outer radial direction, a thrust force is applied to the movable pulley 40tlC, the movable pulley 40 approaches the fixed pulley 39, and therefore the groove width of the V-groove 41 is automatically reduced, and the V-belt 38 moves to the primary sheep 36. is pulled in the direction of the outer diameter.

The secondary sheep 37 is attached to a boss member 45 rotatably attached to the output shaft 32. i.e. 4
6 is a fixed pulley that rotates together with the boss member 45;
47 is a movable pulley rotatably provided with respect to the boss member 45. These fixed pulleys 46 and movable pulleys 47
A V-shaped groove 48 is formed between the V-shaped grooves 48 and the V-shaped groove 48.
The belt 38 is passed over the rack.

The movable pulley 47 is pushed toward the fixed pulley 47 by the spring 49, thereby being biased to constantly reduce the width of the V-shaped groove 48.

As described above, when the V belt 38 is moved in the outer diameter direction on the privacy sheep 36 side due to the increase in the rotational speed of the crankshaft 23, the HvV belt 38 is pulled in the inner diameter direction in the secondary sheep 37, and at this time, the movable pulley 4
2 moves in the axial direction against the spring 49 to form the V-shaped groove 4.
8 groove width is widened. Therefore, the rotation of the crankshaft 23 is transmitted to the secondary sheep 37 at an increased speed.

A centrifugal clutch 50 is attached to the boss member 45, and when the rotational speed of the secondary sheet 37 reaches a predetermined value or more, the centrifugal clutch 50 is activated and transmits the 0 rotation tS of the secondary sheet 3 to the rubbing plate 5. . Friction plate 5
1 is fixed so as to rotate together with the output shaft 32, and therefore, when the centrifugal clutch 5O operates, the rotation of the secondary sheep 37 is transmitted to the output shaft 32.

A small gear 52 is provided on the output shaft 32, and this small gear 52 meshes with a large reduction gear 54 provided on a transmission shaft 53. An ILC reduction gear 55 is provided on the transmission shaft 53, and this reduction gear 55 meshes with a large gear 57 provided on the axle 56. The aforementioned rear axle 13 is attached to the axle 56. Therefore, when the output shaft 32 rotates, it is decelerated by the gears 52, 54, 55, and 56 and transmitted to the rear m13.

Incidentally, an operating mechanism 60 of the present invention is provided on the primary arp 36 side. The operating mechanism 60 is shown in its operative state in FIG. That is, 61 is a suppression dog, and this suppression dog 61 has a pair of pressing arms 62.62f as shown in FIG. These suppressing arms 62, 62 are connected to through holes 63, 6 formed in the fixed pulley 39.
3f and faces the movable pulley 40. Therefore, the push dog 61 rotates integrally with the fixed pulley 39. A spring seat 65 is rotatably mounted on the other end of the pressure dog 61 via a bearing 64 . This spring seat 65 is given thrust by a spring 66. The spring 66 is in contact with the pressing actuator 67. The pressing actuator 67 has a screw spline 68 formed on its outer peripheral surface, and the screw spline 68 is screwed into a screw spline 70 of a nut 69 fixed to the left crankcase 18. Therefore, when rotation is applied to the push actuator 67, the push actuator 67 is displaced in the axial direction by the action of the screw splines 68,70. A lever 7 is fixed to the suppression actuator 67, and one end of a wire 72 is connected to this lever 7.

The other end of the wire 72 is the left grip 5 of the steering handle 4
is connected to. Note that 73 is a cover.

When the left grip 5 of the steering handle 4 is rotated, the lever 71 is pulled and the push actuator 67 is rotated. At this time, the push actuator 67 is moved to the right in FIG. 3 in order to secure the screw spline 68.70. will be moved to. Since the suppression operator 67 presses the spring 66, the pressure dog 61 is moved to the right in the figure. Arm 62 of dog 6.62 is movable pulley 4
0 to the right, thereby forcibly expanding the V-shaped groove 41.

The effect of the pinching in such an embodiment will be explained.

When the left grip 5 of the steering handle 4 is not rotated, the suppression actuator 67 is the third Kyoka Yu 11J.

Therefore, the dog 61 does not completely block the movement of the movable pulley 40 to the left. When a motorcycle is operated in this state, the vehicle speed vs. crankshaft rotation speed characteristics are similar to those of the conventional model, as shown by the middle part in Figure 5. Because it is done,
Achieve low noise and low fuel consumption.

When a strong drive is desired, such as when driving uphill, the left grip 5 is operated to forcibly push the movable pulley 40 of the primary sheep 36 to the right by the dog 61. That is, the movable pulley 4O is operated to reduce the groove width of the V-shaped groove 41 by the centrifugal force of the flyweight 44, but the dog 6O pushes the movable pulley 405 against the thrust of the flyweight 44, Expand character #41. Therefore, the speed increase or decrease in the non-secondary sheep 3 relative to the primary sheep 36 is reduced, and a large torque is generated in the secondary sheep 37. Furthermore, since the rotation speed of the crankshaft 23 is high when such centrifugal force is generated by the flyweight 44, the rear 1 pd, 13 is driven at a high rotation speed and with a large torque. This state is shown by rupture &lB in FIG.

Therefore, pitching ability increases and powerful driving becomes possible.

The present invention relates to a V-belt automatic variable M used for motorcycles.
It is not limited by the machine, but can be applied to anything that wants to change the driving characteristics by changing the gear ratio, which is uniquely set based on the centrifugal force of the flyweight.For example, it can be applied to V-belt automatic transmission of general-purpose engines. It is possible to carry out even if it is a machine.

Further, the operation mechanism is not limited to the structure of the embodiment as long as it has a structure in which the movable pulley on the primary sheep side is forcibly moved against the centrifugal force of the flyweight.

〔Effect of the invention〕

As described above, according to the present invention, the movable pulley Th flyweight on the 1st primary sheep side can be moved against the centrifugal force by operation &a; It can be forcibly changed, and is suitable for, for example, improving the pitching ability of a motorcycle. −

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a side view of a motorcycle, Fig. 2 is a sectional view of its engine unit, and Fig. 3 is a sectional view of the engine unit.
The figure is a sectional view showing an enlarged portion of FIG. 2 in an operating state, FIG. 4 is a perspective view of the suppression dog, and FIG. 5 is a diagram showing the vehicle speed-crankshaft rotation speed characteristic. 1... Frame, 1O... Engine unit, 15
... Engine, 23 ... Crankshaft (drive shaft), 3
2... Output shaft, 35... V-belt automatic transmission, 36
...Primary sheep, 37...Secondary sheep, 3B...V belt, 39...Primary sheep side fixed pulley, 40...Primary sheep side movable pulley, 41...Primary sheep side 7-shaped groove , 44... Fly weight, 46... Secondary sheep side fixed pulley, 47... Secondary sheep side movable pulley, 48...
...Secondary sheave side V-shaped vortex, 49...-spring, 6O river operating mechanism, 61...pressure dog, 65...-spring seat, 66...spring, 67...suppression actuator, 72... ...Wire. Applicant's agent Patent attorney Takehiko Suzue (Figure 3, Figure 4, Figure 5)

Claims (1)

[Claims] A primary sheep with a V-shaped groove formed by a fixed pulley and a movable pulley is installed on the drive shaft, and a secondary sheep with a V-shaped groove formed by another fixed pulley and another movable pulley is attached to the output shaft. , A V-belt that changes the width of the V-groove and automatically changes speed by passing the Beltora rack over these V-grooves and moving the movable boob on the primary sheep side in the axial direction using the centrifugal force of the flyweight. The V-belt automatic transmission is characterized in that the primary sheep side is provided with an operation mechanism that operates against the thrust of all the flyweights of the movable pulley by external operation.