JPH0113875Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is a belt-type continuously variable transmission device that is widely used in agricultural working machines such as combines and agricultural transport vehicles. Applied drive side V
This invention relates to a belt-type continuously variable transmission in which the effective pitch diameters of the belt winding of the pulley and the driven side V-pulley change together during gear shifting.

(Prior art) The above-mentioned belt type continuously variable transmission was developed in 1983-
As described in Publication No. 10039, the sliding pulley piece of the driven side V-pulley is pressed against one side of the fixed pulley by the spring and pinches the V-belt.
The sliding pulley piece of the driving side V-pulley is slid with a cam, etc., and the sliding pulley piece of the driven side V-pulley is slid by the lateral pressure caused by changing the tension of the V-belt, and the driving side V-pulley and the driven side V-pulley are The gears are changed by changing the effective winding pitch diameter.

(Problem to be solved by the invention) The belt-type continuously variable transmission described above has a high torque transmission because the transmission torque of the V-belt is determined by the pressing force of the spring that presses the sliding pulley piece of the driven side V-pulley. In order to transmit the transmission at a constant gear ratio, the pressing force of the spring must be increased. In this case, in order to increase the speed, the sliding pulley piece of the driving side V-pulley must slide by overcoming the pressing force of the spring in order to reduce the effective pitch diameter of the driven side V-pulley. Strong operating force must be applied to the operating lever.

Therefore, it is possible to use a spring to press the sliding pulley piece of the driving pulley toward one side of the fixed pulley, and make the pressing force of the driving side spring equal to the pressing force of the driven side spring and balance it approximately in the middle of the shifting width. There is a configuration like this.

With this configuration, when the speed change operation lever slides the drive side sliding pulley piece to change speed, the drive side and The pressing force of the driven side spring is balanced, and the operating load on the gear shift operating lever becomes zero, so that when the operator changes gears from low to high speed, the operation applied to the gear shift operating lever during this gear shifting process changes from low to high speed. The user experienced a sensory inconvenience in that the automatic movement of the shift operating lever was suppressed until medium speeds were reached, and force was applied to the shift operating lever from middle to high speeds.
In addition, if there is play in the interlocking mechanism that operates the drive-side sliding pulley piece with the speed-change operation lever due to assembly or machining errors, the speed-change operation lever will not be able to handle the pressing force caused by the drive-side and driven-side springs. This has the disadvantage that "play" occurs near the center of the high and low gear shift ranges where the balance becomes zero, and it is not possible to obtain a shift state proportional to the movement of the shift control lever during the shift. Furthermore, if the shift control lever is to be moved to the "stop" position in an unexpected situation, the shift control lever must be moved from the center position of the shift range to the "stop" position by a large distance against the pressing force of the spring. Not only is it not possible to quickly stop the transmission, but if the shift control lever is no longer fixed to the stopped state, the shift control lever will move toward the medium speed range and transmission will occur at medium speed. It was extremely dangerous.

(Means for solving problems) Therefore, the present invention is constructed as follows.

That is, a driving-side speed change pulley 3 consisting of a fixed pulley piece 1 and a sliding pulley piece 2, and a driven pulley consisting of a fixed pulley piece 4 and a sliding pulley piece 5 pressed against the fixed pulley piece 4 by a spring 9. A V-belt is wound around the side speed change pulley 6, and the speed is changed by slidingly operating the sliding pulley piece 2 with a speed change operation lever 10 connected to the sliding pulley piece 2 on the drive side by a link mechanism 15. In the continuously variable transmission, an auxiliary spring 8 is provided to press the sliding pulley piece 2 on the driving side toward the fixed pulley piece 1, and the spring 9 is moved to the position where the driven side variable speed pulley 6 has the maximum effective pitch diameter.
The belt type continuously variable transmission is characterized in that the pressing force of the auxiliary spring 8 is set so that the auxiliary spring 8 is substantially balanced when the sliding pulley piece 5 is pressed.

(Operations and Effects of the Invention) When increasing the speed by moving the sliding pulley piece 2 of the driving side speed change pulley 3 closer to the fixed pulley piece 1 using the speed change operation lever 10, the operation force is reduced by the action of the auxiliary spring 8. That will happen.

Furthermore, when the operator operates the gear shift operating lever 10 from a low speed range to a high speed range, force is gradually applied to the gear shifting operating lever 10, which prevents the above-mentioned problem with the operating sensation of the gear shifting operating lever 10. In addition to being able to eliminate the problem, there is also a shift control lever 1 that changes from low speed range to high speed range.
0, it becomes possible to obtain a speed change ratio proportional to the movement of the speed change operation lever 10. Furthermore, when the speed change operation lever 10 is released, the effective pitch diameter of the driven speed change pulley 6, where the pressing forces of the springs 8 and 9 on the sliding pulleys 2 and 5 are balanced, reaches the maximum, that is, the lowest speed position, and the automatic The shift control lever 1 will be stable at the lowest speed.
The belt-type continuously variable transmission device of this invention is used in the power transmission mechanism to the traveling equipment of combine harvesters or agricultural transport vehicles, in order to be able to move quickly from the high-speed range to the low-speed range without applying much force. In this case, you can drive safely.

(Example) Next, an example of the present invention will be described based on the drawings. Reference numeral 3 designates a driving side speed change pulley, which is provided on the output shaft 12 of the prime mover 11, and 6 represents a driven side speed change pulley, which is provided on the input shaft 14 of the traveling section transmission 13.

The drive-side speed change pulley 3 is composed of a fixed pulley piece 1 attached to the output shaft 12 and a sliding pulley piece 2 fitted so as to be slidable in the axial direction. This sliding pulley piece 2 is always pressed toward the fixed pulley piece 1 side by an auxiliary spring 8, and the shifter 14 fitted on the sliding pulley piece 2 is moved to the link mechanism 1.
The sliding pulley piece 2 is connected to a speed change operating lever 10 via a gear shift lever 5, and is operated by the speed change operating lever 10, thereby causing the sliding pulley piece 2 to slide in the axial direction.

Reference numeral 16 denotes a guide plate for the speed change operation lever 10, which prevents the speed change operation lever 10 from returning to the low speed side due to the reaction force from the sliding pulley piece 2 when the speed change operation lever 10 is placed at a predetermined position within the high/low speed range. A locking recess 20 for hooking is provided in the guide groove 17.

The driven speed change pulley 6 is composed of a fixed pulley piece 4 attached to the input shaft 14 and a sliding pulley piece 5 fitted so as to be slidable in the axial direction of the input shaft 14. This sliding pulley piece 5 is always urged toward the fixed pulley piece 4 by a spring 9.

The spring 9 on the driven side is set to have an elasticity corresponding to the power transmission of the prime mover 11, and when the V-belt 7 is wrapped around and transmitted, the sliding pulley piece 5 will not slide when the required transmission torque is applied. It has strong elasticity to the extent that it does not occur.

The auxiliary spring 8 on the drive side is set to be suitably weaker than the spring 9 on the driven side, so that the shift operation lever 10 is at the lowest speed position, that is, when the effective pitch diameter of the drive side shift pulley 3 is at its minimum, it is on the driven side. The spring force is set so that the respective pressing forces of the springs 8 and 9 on the sliding pulleys 2 and 5 are balanced when the effective pitch diameter of the speed change pulley 6 is at its maximum. That is, at the lowest speed position (position B in FIG. 3), the operating load on the shift operating lever 10 becomes zero. In addition, when setting the appropriate gear ratio, the sliding of the drive side sliding pulley piece 2 to the minimum effective pitch diameter is as follows:
The gear shift operation lever 10 is inserted into the recess 2 of the guide groove 17.
This can be prevented by fixing it to 0.

FIG. 2 shows a state in which the speed change operating lever 10 is at the lowest speed position. Now, shift control lever 10
If the sliding pulley piece 2 is moved to the high-speed side [in the direction of arrow A in the figure], the sliding pulley piece 2 increases the belt-wrapping effective diameter of the drive-side transmission pulley 3 via the link mechanism 15 [in the direction of arrow B in the figure]. Slide to. At this time, the sliding pulley piece 5 on the driven side slides in the direction of arrow C against the pressing force of the spring 9 due to the side pressure of the V belt due to the tension of the V belt 7, and the belt wrapping around the driven side speed change pulley 6 becomes effective. Since the diameter decreases, the rotation of the input shaft 14 of the traveling part transmission 13 increases, and the traveling speed of the aircraft body increases. Here, when the shift operation lever 10 moves to the high speed side, the auxiliary spring 8
This will play a role in reducing the moving operation load. And the gear shift operation lever 1 in this high speed range
0 to the low speed side, the effective belt-wrapping diameter of the drive-side speed change pulley 3 decreases, and the effective belt-wrap diameter of the driven-side speed change pulley 6 increases, contrary to the above. This will cause the aircraft to slow down. By moving the speed change operation lever 10 from the low speed position to the stop position against the pressing force of the auxiliary spring 8 and increasing the groove width W formed by the drive pulley piece 2 and the fixed pulley piece 1, the V-belt 7 can be By riding on the bearing 18, power transmission by the V-belt 7 becomes impossible. That is, at this position, power transmission by the V-belt 7 is cut off.

As described above, the shift operation lever 10 is moved from a high speed range to a low speed range by using the force of the spring 9, which has strong elasticity, pressing the sliding pulley piece 5. When the shift operation lever 10 comes out of the recess 20, the shift is immediately shifted to a low speed state without requiring any force, so it is safe.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a guide groove of a speed change operation lever in a conventional continuously variable transmission, FIG. 2 is a side sectional view showing an embodiment of the continuously variable transmission according to the invention, and FIG. It is an enlarged view in the direction of arrow P in the figure. 1... Drive side fixed pulley piece, 2... Drive side sliding pulley piece, 3... Drive side speed change pulley, 4... Driven side fixed pulley piece, 5... Driven side sliding pulley piece,
6... Driven side speed change pulley, 7... V-belt, 8...
...Auxiliary spring, 9...Spring, 10...
Gear shift operation lever, 15... link mechanism.

Claims (1)

[Scope of utility model registration request] A driving side transmission pulley 3 consisting of a fixed pulley piece 1 and a sliding pulley piece 2, and a driven side transmission consisting of a fixed pulley piece 4 and a sliding pulley piece 5 pressed against the fixed pulley piece 4 by a spring 9. A speed change operation lever 1 has a V-belt wrapped around it and a pulley 6, and is connected to a sliding pulley piece 2 on the driving side by a link mechanism 15.
In a belt type continuously variable transmission device that changes speed by slidingly operating the sliding pulley piece 2 at 0, an auxiliary spring 8 is provided to press the driving side sliding pulley piece 2 toward the fixed pulley piece 1 side, and the driven side speed change is performed. The belt type continuously variable transmission is characterized in that the pressing force of the auxiliary spring 8 is set so that the spring 9 presses the sliding pulley piece 5 to a position where the pulley 6 has a maximum effective pitch diameter and is approximately balanced. Device.