JPH0754956A - Transmission structure for running of working vehicle - Google Patents

Abstract

PURPOSE:To enable a working vehicle to continuously advance and retreat at a low speed using a shift lever certainly and easily, wherein the vehicle is equipped with a continuously variable transmission for running and an advancing and a reversing clutch and is so structured that these transmission and clutches can be operated from one shift lever. CONSTITUTION:A transmission structure for running of a working vehicle comprises a left-right operating path 42 to guide a shift lever 41 in the directions to the left and right, advancing operation path 43 stretching ahead from end of the path 42, and a reverse operation path 44 extending backward from the other end, wherein the continuously variable transmission is turned into the min. speed position when the shift lever 41 is set in the neutral position N in the center about the left and right on the operation path 42, and both an advancing and a reversing clutch are disengaged. When the shift lever 41 is set to the end of the operation path 42, the clutches are put in engagement in the condition that the continuously variable transmission is turned in the min. speed position, and it is possible to advance or retreat the machine body at the lowest speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a work for constructing a traveling transmission system including a continuously variable transmission for traveling, a forward clutch for transmitting power for forward movement, and a reverse clutch for transmitting power for reverse movement. Related to the drive transmission structure of a car.

[0002]

2. Description of the Related Art In a work vehicle equipped with a continuously variable transmission for traveling and forward and reverse clutches as described above, a single gearshift lever is used for shifting operation of the continuously variable transmission and for turning on and off the forward and reverse clutches. May be configured so that
In this case, as shown in FIG.
A left-right operation path 42 'that guides this in the left-right direction, a forward-side operation path 43' that extends forward from the right end of the left-right operation path 42 ', and a reverse-direction operation path 44' that extends rearward from the left end of the left-right operation path 42 '. Some are equipped with.

Thus, as shown in FIG. 4, when the speed change lever 41 is operated to the neutral position N of the left / right operation path 42 ', the continuously variable transmission 1 is operated to the neutral stop position, and the forward and reverse clutches are operated. The aircraft has been stopped and the aircraft has stopped.
When the shift lever 41 is operated to the forward or reverse stop positions FA ′, RA ′ from the state shown in FIG. 4, the forward or reverse clutch is operated (the continuously variable transmission is in the neutral stop position), and the shift lever 41 is moved forward. Side or reverse side operation path 4
Forward or reverse stop position FA 'along 3', 44 ',
When the forward or reverse maximum speed positions FB 'and RB' are operated from RA ', the continuously variable transmission 1 is operated to shift from the neutral stop position to the high speed side.

[0004]

In the structure shown in FIG. 4, when the speed change lever 41 is operated to the forward stop position FA ', the forward clutch is engaged, but the continuously variable transmission remains at the neutral stop position. As it is, the aircraft has stopped. Then, the speed change lever 41 is operated from the forward stop position FA ′ to the forward maximum speed position FB ′ side, and the continuously variable transmission 1 is operated to shift from the neutral stop position to the high speed side, whereby the machine body advances. Therefore, in the structure shown in FIG. 4, when the vehicle body is slowly advanced at a low speed, the gear shift lever 41 is operated to the forward stop position FA ′, and then the gear shift lever 41 is slightly moved to the forward maximum speed position FB ′ side. It is necessary to operate the continuously variable transmission 1 to shift the speed from the neutral stop position to a slightly higher speed. When the vehicle body is moved forward while maintaining such a low speed state, the speed change lever 41 is held at the intermediate position slightly operated from the forward movement stop position FA 'to the forward maximum speed position FB'. I have to continue.

However, it is actually difficult for the operator to hold the speed change lever by hand and accurately keep it at the intermediate position slightly operated from the forward stop position to the forward maximum speed position, and the aircraft will move forward. As a result, the position of the gear shift lever shifts to the high speed side to increase the traveling speed of the aircraft, or the gear shift lever shifts to the forward stop position and the aircraft stops. Further, keeping the gear shift lever in the intermediate position as described above is an operation in which the operator is easily tired.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a work vehicle equipped with a continuously variable transmission for traveling and a forward and reverse clutch so that an operation of continuously moving forward and backward at low speed can be reliably and easily performed.

[0006]

A feature of the present invention is that the traveling power transmission structure for a work vehicle as described above is configured as follows. That is, it is provided with a continuously variable transmission capable of continuously changing gears between a predetermined minimum speed position and a maximum speed position, a forward clutch for transmitting power for forward movement, and a reverse clutch for transmitting power for reverse movement. The left and right operation paths that form a travel transmission system and guide the manually operated speed change lever in the left and right directions, the forward operation path that extends forward from one end of the left and right operation paths, and the other of the left and right operation paths. When the speed change lever is operated to the neutral position of the center of the left and right operation paths, the continuously variable transmission is operated to the lowest speed position, and the forward clutch and reverse operation are provided. When the gear shift lever and the continuously variable transmission, the first clutch and the forward clutch and the reverse clutch are linked to each other so that both the clutches are operated to be disengaged, and the gear shift lever is operated to one end of the left and right operation path Nothing When the transmission is operated to the lowest speed position and the forward clutch is operated, and the gear shift lever is operated from one end of the left and right operation paths to the forward operation path, the forward clutch is continuously operated and continuously operated. When the gear shift lever is operated to the other end of the left and right operation path, there is no gear when the gear shift lever is operated to the high speed side so that the gear shift lever is linked to the continuously variable gear shift mechanism and the forward clutch. When the speed change device is operated to the lowest speed position to operate the reverse clutch, and the gear shift lever is operated to the reverse operation path from the other end of the left / right operation path, the reverse clutch remains in operation. The gear shift lever is provided with a third linkage means for linking the continuously variable transmission and the reverse clutch so that the gear shift operation is performed to the high speed side.

[0007]

With the construction of the present invention, as shown in FIG. 3, for example, the speed change lever 41 is moved to the neutral position N of the left / right operation path 42.
When continuously operated, the continuously variable transmission is operated to the lowest speed position, but both the forward and reverse clutches are disengaged so that the aircraft is stopped. Next, when the shift lever 41 is operated to one end (corresponding to FA) along the left / right operation path 42 from the state shown in FIG. 3, the forward clutch is operated. In this case, since the continuously variable transmission remains at the lowest speed position, the machine body starts to move forward at the lowest speed position of the continuously variable transmission. When the shift lever 41 is operated along the forward operation path 43, the continuously variable transmission shifts from the lowest speed position to the highest speed position with the forward clutch engaged and operated. As described above, by operating the speed change lever 41 to one end (corresponding to FA) along the left and right operation path 42 and abutting it on the left and right operation path 42, the speed change lever 41 is continuously stepped in the forward movement state. It can be kept in the lowest speed position of the transmission.

Next, from the state shown in FIG.
The other end along the left / right operation path 42 (corresponding to RA)
When it is operated to, the reverse clutch is operated. In this case, the continuously variable transmission remains in the lowest speed position,
The aircraft starts to move backward at the lowest speed position of the continuously variable transmission.
When the shift lever 41 is operated along the reverse side operation path 44, the continuously variable transmission shifts from the lowest speed position to the highest speed position with the reverse clutch engaged and operated. As described above, the shift lever 41 is operated to the other end (corresponding to RA) along the left / right operation path 42,
By applying the shift lever 41 to the left and right operation path 42, the shift lever 41 can be held at the lowest speed position of the continuously variable transmission in the reverse drive state.

[0009]

As described above, by setting the continuously variable transmission to the lowest speed position at the left and right ends of the left and right operation paths, the speed change lever is moved to the forward and backward operation paths. Even if the gear is not held at the intermediate position, the continuously variable transmission can be held at the lowest speed position in the forward and reverse states by applying the shift lever to the left and right ends of the left and right operation path.

Thus, the gear shift levers are applied to the left and right end portions of the left and right operation path so that the gear shift levers are securely held without moving and the aircraft continues to move forward and backward at a constant minimum speed. It has become possible to improve the operability of gear shifting of the work vehicle. Further, when the aircraft continues to move forward and backward at a constant minimum speed, the gear shift lever can be applied to the left and right ends of the left and right operation paths as compared with the intermediate position where the gear shift lever is unreliable. The operator with the gear shift lever is less tired.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. (1) FIG. 1 shows a combine truck which is an example of a work vehicle.
1 shows a structure inside a transmission case 8 of a traveling system, in which power from an engine (not shown) is passed through a belt transmission mechanism (not shown) equipped with a tension clutch to drive the belt-type continuously variable transmission 1. The power transmitted from the input pulley 2 and the power from the output shaft 3 of the continuously variable transmission 1 is transmitted to the mowing section (not shown) at the front of the machine body through the output pulley 4.

In the belt type continuously variable transmission 1, each of the input and output pulleys is constructed as a split pulley type with a pair of pulley portions facing each other, and the interval between the pulley portions of the input and output pulleys is changed to form a transmission belt. The speed change operation is performed by changing the winding radius of, and the speed change operation can be performed steplessly between a predetermined minimum speed position and a predetermined maximum speed position. Power from the output shaft 3 of the continuously variable transmission 1 is transmitted through the first gear 5 and the hydraulic forward clutch FC, the first gear 5, the hydraulic reverse clutch RC, the reverse gear 6 and the second gear. The transmission system via 7 is divided into two systems in parallel and transmitted to the first transmission shaft 9.

The forward power (forward clutch FC) or the reverse power (reverse clutch RC) transmitted to the first transmission shaft 9 is transmitted to the second via the second gear 7 and the third gear 10.
It is transmitted to the transmission shaft 11. A shift gear 12 is slidably fitted to the second transmission shaft 11 by a spline structure, and the high speed gear 1 is attached to the third transmission shaft 13 in response to the shift gear 12.
5, the medium speed gear 16 and the low speed gear 17 are fixed.
As a result, the shift gear 12 is slid and engaged with the high-speed gear 14, the medium-speed gear 16, or the low-speed gear 17 that meshes with the high-speed gear 15 to shift the power to three stages of high, medium, and low. Fourth gear 19 that meshes with 16
Be transmitted to.

Right and left side gears 21 are relatively rotatably fitted onto a support shaft 20 for supporting the fourth gear 19, and the input gears 23 of the left and right axles 22 are constantly meshed with the left and right side gears 21. There is. As a result, the right or left side gear 21 is slid with respect to the fourth gear 19 to occlude
The power transmission and the transmission interruption operation are performed on the crawler type traveling device 24 by separating them from each other.
9 and the left and right side gears 21 between the side clutch 25
Is configured.

As shown in FIG. 1, a multi-plate side brake 26 is provided between the left and right side gears 21 and the transmission case 8 at both left and right ends of the support shaft 20,
The side gear 21 is urged by the spring 27 toward the side of engagement with the fourth gear 19. As a result, the right or left side gear 21 is operated to be separated from the fourth gear 19 and operated.
When the side brake 26 is pressed and operated by the pressing portion 28, the traveling device 24 on one side is braked and the machine body makes a turning turn.

(2) Next, the sliding operation structure of the left and right side gears 21 will be described. As shown in FIG. 2, the hydraulic oil from the pump 29 is supplied to the hydraulic cylinders 31 for the left and right side gears 21 via the first switching valve 30. The hydraulic cylinder 31 is internally provided with a spring (not shown) that biases the contraction side. The hydraulic pressure is applied until the side gear 21 moves away from the fourth gear 19 and moves to the neutral stop position where the side brake 26 is not pressed and operated. When the cylinder 31 extends, a drain oil passage 32 is provided for draining hydraulic oil from the hydraulic cylinder 31 to stop the hydraulic cylinder 31 at the neutral stop position. The drain oil passage 32 is connected to a variable relief valve 33. There is.

An operating lever 3 for turning operation is provided on the control section of the machine body.
4 is provided, and the operation lever 34 and the first switching valve 30 are provided.
The variable relief valve 33 and the variable relief valve 33 are mechanically linked via the linking mechanisms 35 and 36. In the state shown in FIG. 2, the operating lever 34 is operated to the neutral position N, the left and right side gears 21 are engaged with the fourth gear 19, and the power of the fourth gear 19 is transmitted to the left and right traveling devices 24. The aircraft is going straight.

When the operating lever 34 is operated to the right or left first turning position R1 or L1 from this state, only the first switching valve 30 is switched and hydraulic oil is supplied to one hydraulic cylinder 31, and the right hydraulic cylinder 31 is supplied. Alternatively, the left side gear 21 is slid by the operation arm 37 and separated from the fourth gear 19. In this case, since the variable relief valve 33 is in the fully open state, the right or left side gear 21 moves to the side brake 26.
At the neutral stop position before pressing, the drain oil passage 32 opens and hydraulic oil escapes from the variable relief valve 33, so that the right or left side gear 21 stops at this neutral stop position. As a result, the side clutch 25 in which the transmission to the right or left traveling device 24 has been cut off is in the disengaged state, and the aircraft gently turns to the right or left.

The operating lever 34 is moved to the right or left first
The second turning position R2, which is right or left from the turning positions R1, L1
When operated to L2, the variable relief valve 33 is gradually throttled, the hydraulic cylinder 31 extends from the neutral stop position, and the pressing portion 28 of the right or left side gear 21 is pulled.
Thus, the right or left side brake 26 is turned on and operated. As a result, the right or left traveling device 24 is braked, and the aircraft makes a right turn or left turn. Further, when the operation lever 34 is operated between the first turning position R1, L1 and the second turning position R2, L2, the hydraulic oil is drained from the hydraulic cylinder 31 from the above-mentioned state, and the pressing force on the side brake 26 is weakened. To be As a result, the side brake 26 slips, and the braking force on the right or left traveling device 24 can be arbitrarily changed.

(3) Next, the operating structure of the continuously variable transmission 1 and the forward and reverse clutches FC and RC shown in FIG. 1 will be described. As shown in FIG. 2, the hydraulic oil of the pump 29 is the pressure reducing valve 38.
Is supplied to the forward clutch FC, the reverse clutch RC, and the stop brake 18 via the second switching valve 39 and the accumulator 40. As shown in FIG. 1, the stop brake 18 is provided between one end of the third transmission shaft 13 and the mission case 8. The stop brake 18 is engaged with the left and right side gears 21 with the fourth gear 19. By turning on and off, the left and right traveling devices 24 can be braked.

As shown in FIG. 3, a gear shift lever 41 is provided in the control section of the machine body, and the gear shift lever 41, the continuously variable transmission 1 in FIG. 1 and the second switching valve 39 in FIG. 2 mechanically. It is linked. A left-right operation path 42 that guides the speed change lever 41 in the left-right direction of the machine body, a forward-side operation path 43 that extends forward from the right end of the left-right operation path 42, and a reverse-direction operation path 44 that extends rearward from the left end of the left-right operation path 42. I have it. When the speed change lever 41 is positioned in the left / right operation path 42, the speed change lever 41 is biased to return to the neutral position N in the left / right center of the left / right operation path 42, and the speed change lever 41 is moved forward and backward. When positioned on the operation paths 43 and 44, the shift lever 41 is biased to return so as to return to the left and right operation path 42.

The state shown in FIG. 3 is a state in which the speed change lever 41 is operated to the neutral position N in the left-right center of the left-right operation path 42, and the second switching valve 39 is moved to the neutral position 39N as shown in FIG. It is being operated. In this state, the continuously variable transmission 1 shown in FIG. 1 is operated to the lowest speed position, but the hydraulic oil is drained from both the forward and reverse clutches FC and RC and turned off to supply the hydraulic oil to the stop brake 18. Then, this is entered and operated, and the aircraft is stopped (the above is equivalent to the first linking means).

Next, from the state shown in FIG.
The lowest forward speed position F at the right end along the left / right operation path 42
When operated to A, the second switching valve 39 shown in FIG. 2 is operated to the forward drive position 39F, the stop brake 18 is turned off, and the forward drive clutch FC is turned on. In this case, since the continuously variable transmission 1 of FIG. 1 is left at the lowest speed position, the vehicle body starts to move forward at the lowest speed position of the continuously variable transmission 1.
When the shift lever 41 is operated from the lowest forward speed FA to the highest forward speed FB along the forward operation path 43, the second switching valve 39 shown in FIG. 2 is operated to the forward position 39F. Thus, the continuously variable transmission 1 in FIG. 1 is shifted from the lowest speed position to the highest speed position side, and at the forward maximum speed position FB of the forward operation path 43, the continuously variable transmission 1 becomes the highest speed position. (Corresponding to the second linking means).

Next, from the state shown in FIG.
Along the left-right operation path 42, the lowest reverse speed position R of the left end
When operated to A, the second switching valve 39 shown in FIG. 2 is operated to the reverse position 39R, the stop brake 18 is turned off, and the reverse clutch RC is turned on. In this case, since the continuously variable transmission 1 in FIG. 1 is left at the lowest speed position, the vehicle body starts to move backward at the lowest speed position of the continuously variable transmission 1.
Then, when the shift lever 41 is operated from the lowest reverse speed position RA to the highest reverse speed position RB along the reverse operation path 44, the second switching valve 39 shown in FIG. 2 is operated to the reverse position 39R. Thus, the continuously variable transmission 1 in FIG. 1 is shifted from the lowest speed position to the highest speed position, and the continuously variable transmission 1 becomes the highest speed position at the reverse highest speed position RB of the reverse side operation path 44. (The above is equivalent to the third linking means).

[Other Embodiment] The belt type continuously variable transmission 1 in the configuration shown in FIG. 1 may be configured as a continuously variable transmission 1 using a tapered cone. Further, instead of the hydraulic forward and reverse clutches FC and RC shown in FIG. 1, the forward and reverse clutches FC and RC may be configured as an articulated dog clutch type. The present invention can be applied not only to the combine as shown in FIG. 1 but also to a four-wheel type work vehicle equipped with front wheels and rear wheels.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a transmission structure in a mission case.

FIG. 2 is a hydraulic circuit diagram of left and right side gear hydraulic cylinders, a first switching valve and a variable relief valve, a second switching valve, forward and reverse clutches, and the like.

FIG. 3 is a plan view showing a shift lever, a left / right operation path, a forward operation side and a reverse operation side.

FIG. 4 is a plan view showing a gear shift lever, a left / right operation path, a forward side and a reverse side operation paths in a conventional technique.

[Explanation of symbols]

 1 continuously variable transmission 41 speed change lever 42 left and right operation path 43 forward side operation path 44 reverse side operation path FC forward clutch RC reverse clutch N neutral position

Claims (1)

[Claims] 1. A continuously variable transmission (1) capable of continuously shifting between a predetermined minimum speed position and a maximum speed position, a forward clutch (FC) for transmitting power for forward movement, and a reverse clutch for reverse movement. A left and right operation path (42) that configures a traveling transmission system including a reverse clutch (RC) that transmits power and guides a manually operated speed change lever (41) in the left and right direction, and the left and right operation path ( Four
2) Forward side operation path (4) that extends forward from one end of
3) and a reverse side operation path (44) extending rearward from the other end of the left / right operation path (42), and the shift lever (41) is located at the center of the left / right operation path (42). When operated to the neutral position (N), the continuously variable transmission (1) is operated to the lowest speed position, and both the forward clutch (FC) and the reverse clutch (RC) are disengaged. A first linking means for linking the speed change lever (41) with the continuously variable transmission (1), the forward clutch (FC) and the reverse clutch (RC); and the speed change lever (41) of the left and right operation path (42). When operated to one end, the continuously variable transmission (1) is operated to the lowest speed position to move the forward clutch (FC).
Is operated and the shift lever (41) moves from one end of the left and right operation path (42) to the forward operation path (4).
3), when the forward clutch (FC) is turned on and operated, the continuously variable transmission (1) and the continuously variable transmission are arranged so that the continuously variable transmission (1) shifts to a high speed side. Second linking device (1) and forward clutch (FC)
When the linking means and the speed change lever (41) are operated to the other end of the left and right operation path (42), the continuously variable transmission (1) is operated to the lowest speed position and the reverse clutch ( RC)
Is operated and the shift lever (41) moves from the other end of the left-right operation path (42) to the reverse operation path (4).
4), so that the continuously variable transmission (1) is operated to shift to the high speed side with the reverse clutch (RC) being operated, the speed control lever (41) and the continuously variable transmission are operated. Third linking device (1) and reverse clutch (RC)
A work transmission structure for a work vehicle, which is provided with a linking means.