JPS59222658A - V-belt type automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To cause different reduction ratios to be obtained from the specified number of revolutions of an engine, by a method wherein the spring constant of a spring pressing the slide disc of a driven pulley is varied. CONSTITUTION:Under a condition in which a control device 57 is pressed by a press lever 69, since a large size part 59b of an actuating lever 59 supports a locking ball 65, the locking ball 65 is protruded from a locking hole 53 and engages with a locking groove 45 in a slide ring 41. This causes the slide ring 41 to be secured to a spacer 29, and as a result, only the spring 41, on the slide disc 33b side, which forms a spring member 39, works as a spring member 39. Thus, the spring constant of the spring member 39 is increased as compared with a constant prevailing at a time when the control device 57 is not pressed by the press lever 69. As a result, a force pressing the slide disc 33b is increased, and thereby the diameter of contact of a V-belt is hard to decrease, and a reduction ratio is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a belt-type automatic transmission used in scooters and the like.

This type of belt-type automatic transmission includes a drive pulley provided on the crankshaft of the engine, and a driven pulley provided on the driven shaft and connected to the drive pulley by a V-belt, and the drive pulley is connected to the drive pulley by a V-belt. The driven pulley is composed of a fixed plate fixed to the crankshaft and a sliding plate slidably inserted into the crankshaft and moved in the direction of the fixed plate according to the rotational speed of the engine. It is comprised of a stationary plate fixed to the driven shaft and a sliding plate slidably inserted into the driven shaft and pressed toward the fixed device by a spring.

For this reason, the above-mentioned belt type automatic transmission has a means for sliding the sliding plate of the drive pulley according to the engine speed (using a weight that moves by centrifugal force), and a sliding plate of the driven pulley. The winding diameter of the V-belt is determined by the interaction with the repulsive force of the compression spring that presses the V-belt, so the speed reduction ratio is determined and the rotational torque of the driven shaft is determined based on the constant rotation of the engine.

However, in general, vehicles require large rotational torque at the drive wheels when driving on a hill or during sports driving, but not necessarily when driving steadily on a flat road.
It is desirable that the rotational torque of the drive wheels can be selected as appropriate.

An object of the present invention is to provide a belt-type automatic transmission for a vehicle that can provide different speed reduction ratios and thus different rotational torques and rotational speeds to the driving wheels from a constant engine rotation.

This object was achieved by changing the spring constant of the spring pressing against the sliding plate of the driven pulley.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a flat-type motorcycle according to the present invention will be described with reference to the drawings.

Reference numeral 11 denotes a drive unit case, and this case 11 supports an engine 13, a driven shaft 15, a rear wheel shaft 17, and a reduction gear portion 19 that transmits rotation of the driven shaft 15 to the rear wheel shaft 17.

Engine 13 has a crankshaft 21 . A drive pulley 23 is provided on this crankshaft 21. The drive pulley 23 consists of a fixed plate 23a fixed to the crankshaft 21 and a sliding plate 23b spline-coupled to the crankshaft 21 and slidably fitted therein. A weight 27 supported by a support plate 25 is movably installed on the back surface of the sliding plate 23b. When the crankshaft 21 rotates, this weight 27 moves outward due to centrifugal force depending on the number of rotations of the crankshaft 21, and presses the sliding plate 23b toward the fixed plate 23a.

Next, a cylindrical spacer 29 is fitted and fixed to the driven shaft 15. And this spacer 29 has ■belt 3
A driven pulley 33 connected to the driving pulley 23 via 1
is provided. The driven pulley 33 includes a fixed plate 33a fixed to the spacer 29 and a sliding plate 33b slidably inserted into the spacer 29. Reference numeral 35 denotes a cylindrical spring case with a bottom, which is fixed to the sliding plate 33b at the opening and has a spacer 29 at the bottom 35a.
It is slidably engaged with the spline 37 of. A compression spring member 39 is housed within this case 35 . The compression spring member 39 is supported by the spacer 29 at one end, and presses the sliding plate 33b toward the fixed plate 33a together with the spring case 35 at the other end.

Hereinafter, the spring constant converting means for the compression spring member 39, which is a feature of the present invention, will be explained.

Reference numeral 41 denotes a sliding ring having a flange 43, which is slidably inserted into the spacer 29 within the spring case 35, and has a locking groove 45 on its back surface. The spring member 39 is attached to this sliding ring 4.
A pair of springs 47.4 connected in series via the collar 43 of 1
Consists of 9. Note that the locking groove 4 on the back surface of the sliding ring 41
5 is engaged with a locking body 65, which will be described later.

Next, the driven shaft 15 passes through the shaft hole 51 which is open at one end and has a reduced diameter at the deep end, and also through the spacer 29.
It has a locking hole 53 that opens to the outside space.

An operating device 57 is slidably inserted into the shaft hole 51 via a compression spring 55 . The operating member 57 includes an operating rod 59 having a small diameter portion 59a at its tip, an operating rod 61 located behind the operating rod 59, and a spring constant higher than that of the spring 55 interposed between the operating rod 59 and the operating rod 61. It consists of a large compression spring 63. A locking body 65 is loosely fitted into the locking hole 53. This locking body 65 is attached to the locking hole 53 when the small diameter portion 59a of the working rod 59 is located at the locking hole 53.
3 and does not engage with the locking groove 45 of the sliding ring 41, but when the large diameter portion 59b of the working rod 59 is at the position of the locking hole 53, it does not engage with the locking groove 45 of the sliding ring 41. When engaged, the sliding ring 41
stop sliding.

Reference numeral 67 denotes a surface portion, which is integrally formed with the drive unit case 11 on the outside of the outer end of the driven shaft 15. A pressing lever 69 is installed in this surface portion 67 so as to be swingable about a shaft 71 so as to press the head of the operating device 57 . 7
3 is an operating lever installed on the steering handle 75;
It is connected to the pressing lever 69 via a Bowden wire 77. Therefore, by operating the operating lever 73, the pressing lever 69 is swung, and the operating rod 61 is moved into the shaft hole 51.
It can be taken in and out. Note that the return of the operating member 57 from the shaft hole 51 is performed by a compression spring 55.

Next, the operation of this embodiment will be explained.

First, in a normal state in which the operating device 57 is not pressed by the pressing lever 69, the small diameter portion 59a of the operating rod 59 is attached to the locking ball 6.
5, the locking method 65 sinks into the locking hole 53 and does not engage with the lock 845 of the sliding ring 41. Therefore, the sliding ring 41 can freely slide on the spacer 29, and the pair of springs 47 and 49 forming the spring member 39 work like a single spring.

On the other hand, when the operating device 57 is pressed by the pressing lever 69 (the state shown in FIG. 2), the large diameter portion 59b of the operating rod 59 supports the locking method 65, so that the locking method 65 protrudes from the locking hole 53. It engages with the locking groove 45 of the sliding ring 41. Therefore, the sliding ring 41 is fixed to the spacer 29, and only the spring 41 on the sliding M33b side constituting the spring member 39 acts as the spring member 39. Therefore, the spring constant of the spring member 39 is adjusted by the pressing lever 69 to control the operating device 57. becomes larger than when not pressed. As a result, the force that presses the sliding plate 33b increases, so that the winding diameter of the belt becomes smaller (and the reduction ratio obtained when the engine 13 rotates at a constant speed is This is smaller than when the device 57 is not pressed, and the rotational torque of the driven shaft 15 is also smaller.

Therefore, if the constant of this spring 47 is determined to be suitable for shifting during steady running, the spring 49 can be added in series, so that when the operating device 57 is released, the spring 47
Since the overall spring constant of the spring 49 is large, the winding diameter of the belt around the driven pulley 33 tends to be small (this makes it possible to increase the rotational torque of the driven shaft 15, which is effective when climbing up a hill, etc. .

Although the embodiments described above relate to motorcycles, they can also be applied to small four-wheeled vehicles.

In the V-belt automatic transmission for vehicles according to the present invention, in this type of V-belt automatic transmission for vehicles, a spring constant converting means is installed in the pressure spring of the driven pulley, so that the spring constant of the spring can be changed. Since it can be changed as appropriate, different reduction ratios can be easily obtained from an engine that rotates at a constant rate, and thus different rotational speeds and rotational torques can be easily obtained at the driven wheels.

Therefore, a vehicle using this automatic transmission applies a large rotational torque to the drive wheels when riding on a hill or during sports driving.
This is extremely convenient because a small rotational torque can be selectively applied during steady driving on a flat road.

[Brief explanation of drawings]

The drawings show an embodiment of a scooter according to the present invention, and FIG. 1 is a cross-sectional view of the drive section of the scooter, and FIG.
13... Engine 15... Driven wheel 21... Crankshaft 23... Drive Pulley (23a...fixed plate, 23b...sliding plate) 31
... ■Belt 33 ... Driven pulley (33a...fixed plate, 33b...sliding plate) 39
... Spring (spring member) 4L43, 45, 47, 49, 51.53.55, 57
, 65.67... Spring constant conversion means (41... Sliding ring, 43... Flange. -3← 45... Locking groove, 47.49... Spring. 51... Shaft Hole, 53... Locking hole. 55... Compression spring, 57... Operating device.

Claims (1)

[Claims] (1) A drive pulley provided on the crankshaft of the engine, and a driven pulley provided on the driven shaft and connected to the drive pulley by a V-belt, the drive pulley being a fixed plate fixed to the crankshaft. and a sliding plate that is slidably inserted into the crankshaft and moves toward the fixation device according to the rotational speed of the engine, and the driven pulley is fixed to the driven shaft. A V-belt type automatic transmission for a vehicle, which is composed of a fixed plate and a sliding plate slidably inserted into the driven shaft and pressed toward the fixed plate by a compression spring. V-belt type % type % for vehicles equipped with constant conversion means