JPH0133878Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention involves winding a transmission belt around pulleys provided on the drive shaft and the driven shaft, and changing the effective winding diameter of one of the pulleys. The present invention relates to a belt type continuously variable transmission in which the rotation speed is changed relative to the rotation of a drive shaft, and the speed change operation can be easily performed.

(Prior art) In conventional belt-type continuously variable transmissions, in order to perform an operation of sliding the movable pulley piece of the pulley in the axial direction to change the effective winding diameter, for example,
In the invention described in Publication No. 40375, as shown in Figure 3,
A device in which a sliding pulley piece 51 is directly operated by a control lever 50 is known. In this configuration,
The sliding pulley piece 51 slides in the direction of the shaft 54 so as to be separated from the fixed pulley piece 52 against the elasticity of the compression spring 53 that always presses and urges the sliding pulley piece 51 toward the fixed pulley piece 52.

(Problem to be solved by the invention) In such a conventional transmission device, the compression spring 53 only transmits power by sandwiching the transmission belt 55 between the sliding pulley piece 51 and the fixed pulley piece 52. Since it exerts a large pressing force, the sliding operation must be performed with a very large operating force, making it difficult to perform a speed change operation.

(Means for Solving the Problems) Therefore, the present invention is configured as follows so that the speed change operation can be easily performed using the rotational driving force of the rotating shaft. That is, the transmission belt 5 is wound around the split pulley 3 consisting of the movable pulley piece 3a and the fixed pulley piece 3b, and the movable pulley piece 3a approaches and separates from the fixed pulley piece 3b, thereby effectively winding the split pulley 3. In a belt-type continuously variable transmission that changes the gear ratio of a driven shaft 2 to a drive shaft 1 by changing its diameter, the rotation of the drive shaft 1 is converted into axial forward and backward movement of a sliding shaft 9 via a clutch 7. A gear shift assist device A is provided,
The forward and backward movement of the sliding shaft 9 and the movement of the movable pulley piece 3a toward and away from the fixed pulley piece 3b are linked, and the gears are changed by operating the clutch 7 of the gearshift auxiliary device A.

(Operation and effect of the invention) When performing a speed change operation, if the clutch 7 of the speed change auxiliary device A is operated and the sliding shaft 9 is moved forward and backward in the axial direction by the rotational driving force of the drive shaft 1, the movable pulley The piece 3a moves to change the effective winding diameter of the split pulley 3 to change speed.

In this way, since the movable pulley piece 3a is moved using the rotational driving force of the drive shaft 1, it is possible to simply switch the clutch 7 without using a special driving source or requiring strong operating force. The mechanism is simple and the gear shifting operation is easy.

(Example) Next, an example of the present invention will be described with reference to the drawings.

FIG. 2 shows a transport vehicle equipped with a continuously variable transmission according to the present invention. The continuously variable transmission device is provided in the middle of a power transmission path for traveling from the prime mover 11 to the drive wheels 14 which are pivotally supported by the wheel pipes 13 of the transmission 12.

A V-belt 19 is wound between an engine pulley 16 fixed to the output shaft 15 of the prime mover 11 and a counter pulley 18 fixed to a counter shaft 17 provided parallel to the output shaft 15, and the power transmission between them is steered. This is done by turning on and off a travel tension clutch 21 linked to a travel clutch lever (not shown) provided near the handle 20. Counter axis 1
7 and an input shaft 22 to the transmission 12, which is provided parallel to the counter shaft 17, is provided with a continuously variable transmission, and the power transmission between them is performed by the transmission belt 5. Therefore, the power output from the prime mover 11 is transmitted to the counter shaft 17 by the V-belt 19, and then from the counter shaft 17 to the transmission 1 by the transmission belt 5 of the continuously variable transmission.
The power is transmitted to the input shaft 22 to the drive wheels 14 and then shifted within the transmission 12.
The transport vehicle is driven by the transport vehicle. Here, the drive shaft 1 referred to in the present invention refers to the counter shaft 17,
Further, the driven shaft 2 refers to the input shaft 22.

Next, the continuously variable transmission will be explained in detail with reference to FIG.

The continuously variable transmission device includes a split pulley 3 provided on the counter shaft 17, a split pulley 4 provided on the input shaft 22, a transmission belt 5 stretched between them, and a transmission that changes the effective winding diameter of the split pulley 3. It consists of the operating casing 8 of the auxiliary device A.

The split pulley 3 consists of a fixed pulley piece 3b fixed to the counter shaft 17 with a bolt 23, and a movable pulley piece 3a that is slidable in the axial direction of the counter shaft 17 and provided opposite to the fixed pulley piece 3b. ,or,
The split pulley 4 includes a fixed pulley piece 4b fixed to the input shaft 22 with a bolt 24, and this fixed pulley piece 4b.
The movable pulley piece 4a is provided facing the axially movable pulley piece 4a and is normally biased toward the fixed pulley piece 4b by a compression spring 25 and is slidable in the axial direction. The transmission belt 5 wound between these split pulleys 3 and 4 is always applied with lateral pressure by the compression spring 25, and the lateral pressure due to the elasticity of the compression spring 25 is applied by the transmission belt 5 to transmit the running power of the transport vehicle. The size is set to be large enough to obtain.

The speed change auxiliary device A for changing the effective winding diameter of the split pulley 3 is provided at the shaft end portion of the counter shaft 17 to which the split pulley 3 is attached, and connects the input shaft 26 of the operating casing 8 and the end of the counter shaft 17. Power is input into the working casing 8 by connecting through the joint 27.

The input shaft 26 has a hexagonal portion 26a in the rotation direction.
A clutch 7 is provided with friction surfaces 7a, 7a formed on both end surfaces, which is subject to restrictions in the axial direction, but is slidable in the axial direction.
On the left and right sides of this clutch 7 are friction gears 2 which are normally rotatable but become capable of receiving rotational power and transmitting power when the clutch 7 comes into contact with them.
8 and 29 are provided. One friction gear 28 is always in mesh with a reversing output gear 30 fixed to the output shaft 6. The other friction gear 29 is always in mesh with a large-diameter intermediate gear 32 fixed to an intermediate shaft 31, and another small-diameter intermediate gear 33 fixed to the intermediate shaft 31 is connected to a normal rotation output gear 34 fixed to the output shaft 6. It's meshing with each other. That is, if the clutch 7 comes into pressure contact with the friction gear 28, the rotation direction of the output shaft 6 will be opposite to that of the input shaft 26, and if the clutch 7 comes into pressure contact with the friction gear 29, the rotation direction will be the same as that of the input shaft 26. becomes. In this embodiment, when the output shaft 6 is rotated in the same direction as the input shaft 26 (hereinafter referred to as normal rotation), the gear ratio in the operating casing 8 is 1:3.7, and ,
When rotating in the opposite direction to the input shaft 26 (hereinafter referred to as reverse rotation), the gear ratio is 1:2.2.

A threaded portion 6a is formed at the end of the output shaft 6, and a sliding shaft 9 is provided by screwing into the threaded portion 6a. It slides back and forth in the direction. When the output shaft 6 rotates in the normal direction, the sliding shaft 9 slides in the direction of the arrow A in the figure, and when the output shaft 6 rotates in the reverse direction, the slide shaft 9 slides in the direction of the arrow B in the figure.
The screw direction of a is determined.

At the end of the sliding shaft 9 provided at the end of the output shaft 6,
an actuating arm 10 that engages with a pin 35 in an annular groove provided in a boss portion of the movable pulley piece 3a of the split pulley 3;
The operating arm 10 reciprocates in the axial direction of the counter shaft 17 by moving the sliding shaft 9 forward and backward in the sliding shaft direction about the fulcrum 36. Therefore, by sliding the sliding shaft 9 in the A direction, the actuating arm 10 swings so as to bring the movable pulley piece 3a closer to the fixed pulley piece 3b, thereby increasing the effective winding diameter of the split pulley 3. By sliding in the direction B, the effective winding diameter of the split pulley 3 is reduced by swinging away from the fixed pulley piece 3b. When the effective winding diameter of the split pulley 3 increases or decreases, the effective winding diameter of the split pulley 4 also increases or decreases.

Since the split pulley 3 is located on the upper transmission side of the traveling transmission path with respect to the split pulley 4, the sliding shaft 9
The vehicle speed of the transport vehicle is increased by sliding in the A direction, and the vehicle speed is decreased by sliding in the B direction. Further, as mentioned above, the fact that the gear ratio of the operating casing 8 when the sliding shaft 9 slides in the A direction, that is, when the output shaft 6 rotates in the normal direction, is larger than when it rotates in the reverse direction means that when the vehicle speed increases, the sliding shaft 9
will operate more slowly than when decelerating,
Therefore, the sliding speed of the movable pulley piece 3a is also slower when increasing the speed than when decelerating.

37 is an operating arm that slides the clutch 7 in the direction of the input shaft 26, and this operating arm 37 and a vehicle speed setting lever 3 provided near the steering handle 20
8 is linked with rod 39. In addition, 40 is a speed display needle linked by a rod 41 to the actuating arm 10 that operates the movable pulley piece 3a, and the speed display needle is provided with an elongated hole 42a partitioned into "high speed range", "medium speed range", and "low speed range". It is provided so as to be located within the elongated hole 42a of the display board 42.

The speed display board 42 and the vehicle speed setting lever 3
8 are placed close to each other, and the operator sets the vehicle speed of the transport vehicle to a desired speed using the vehicle speed setting lever 38 while observing the vehicle speed range pointed by the speed display needle 40 on the speed display board 42. .

When the desired vehicle speed is achieved by operating the clutch 7, the clutch 9 is disengaged. At this time, a force is generated on the sliding shaft 9 due to the pressing force of the compression spring 25 to return it to its original position, but the sliding shaft 9
Since the output shaft 6 is screwed onto the output shaft 6, rotational resistance is large and the output shaft 6 is held in the same position.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is an enlarged plan sectional view of the main part with a part cut away, and FIG. 2 is a plan view of the whole. Further, FIG. 3 is a plan view showing the prior art. 1... Drive shaft, 2... Driven shaft, 3... Split pulley, 3a... Movable pulley piece, 3b... Fixed pulley piece, 5... Transmission belt, 7... Clutch, A...
Gear shifting aid.

Claims (1)

[Scope of utility model registration request] The transmission belt 5 is wound around the split pulley 3 consisting of a movable pulley piece 3a and a fixed pulley piece 3b, and the effective winding diameter of the split pulley 3 is adjusted by moving the movable pulley piece 3a toward and away from the fixed pulley piece 3b. In a belt-type continuously variable transmission that changes the gear ratio of the driven shaft 2 to the drive shaft 1 by changing the speed ratio of the driven shaft 2 to the drive shaft 1, a shift assist device that converts the rotation of the drive shaft 1 into axial forward and backward movement of the sliding shaft 9 via the clutch 7. A device A is provided to control the forward and backward movement of the sliding shaft 9 and the fixed pulley piece 3 of the movable pulley piece 3a.
A shift operating device for a belt-type continuously variable transmission in which the gears are changed by operating a clutch 7 of a shift auxiliary device A by interlocking approaches and separations from the gear shift device A.