JPH0733045A - Turning operation structure for working vehicle - Google Patents

Abstract

PURPOSE:To enable the selective operation of a turning state to be effected by one hand even during traveling while holding a turning operating tool in a working vehicle provided with slow turning mechanism and rapid turning mechanism for imparting speed difference to a lateral pair of travel devices to turn a body so as to be changed over to a slow turning state by the slow turning mechanism and to a rapid turning state by the rapid turning mechanism. CONSTITUTION:A turning operation tool 39 is provided with a change-over operating means 5 for performing human-initiated selective change--over operation into a slow turning state and a rapid turning state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turning operation structure for a work vehicle provided with a pair of left and right traveling devices such as multi-wheel type or crawler type having four wheels on each side.

[0002]

2. Description of the Related Art As an example of a work vehicle as described above, there is a combine equipped with a pair of left and right crawler type traveling devices.
An example of the turning operation structure is disclosed in Japanese Patent Laid-Open No. 4-321473. In such a combine, a gentle turning mechanism that transmits a normal rotation power at a speed lower than that of the other traveling device to the selected traveling device (see FIG. 2 of the above publication).
(11, 9 and RC in FIG. 2) and a rapid turning mechanism that transmits reverse power to one of the selected traveling devices (1 in FIG. 2 of the above publication).
1, 27, 28, 9, RC) and is capable of artificially selecting and switching between a slow turning state by operating the slow turning mechanism and a quick turning state by operating the rapid turning mechanism. Some are equipped with a lever (32 in FIG. 2 of the above publication) (corresponding to a switching operation tool).

Thus, when the operation lever (40 in FIG. 3 of the above publication) (corresponding to the turning operation tool) is operated to the left or right while the switching lever is operated to select the gentle turning state, The mechanism operates and one of the traveling devices is driven to rotate in the normal direction at a low speed, and the vehicle body slowly turns with a relatively large turning radius due to the speed difference between the left and right traveling devices. Then, when the operating lever is operated to the left or right while the switch lever is operated to select the sudden turning state, the rapid turning mechanism operates and one of the traveling devices is driven in the reverse direction, so that the aircraft is suddenly turned with a small turning radius. It turns.

[0004]

In the above-mentioned structure, the operation lever for turning operation and the switching lever for selecting the turning state (slow turning state and rapid turning state) are separately provided. In this case, it is not possible to release the hand from the operating lever for turning operation during traveling, so for example, while operating while holding the operating lever with the right hand and operating the switching lever with the left hand, the turning state can be switched. There is room for improvement in terms of operability because it is in such a state. SUMMARY OF THE INVENTION It is an object of the present invention to provide a work vehicle capable of selectively switching between a gentle turning state and a sharp turning state as described above, so that the turning state can be easily switched.

[0005]

A feature of the present invention resides in the following structure in the turning operation structure of a work vehicle as described above. That is, a gentle turning mechanism that causes a speed difference between the pair of left and right traveling devices to turn the vehicle body, and a rapid turning mechanism that causes a speed difference between the pair of left and right traveling devices to cause a larger speed difference than the gentle turning mechanism to turn the vehicle body are provided. A gentle turning state in which the gentle turning mechanism is operable and the rapid turning mechanism is stopped, and a rapid turning state in which the rapid turning mechanism is operable and the gentle turning mechanism is stopped are provided with a switching unit capable of selective switching operation, It is equipped with a single turning operation tool that turns the machine to the right or left by operating the slow turning mechanism or the sharp turning mechanism by artificially operating to the right or left. The turning operation tool is provided with a switching operation tool for performing a selective switching operation depending on the state.

[0006]

When the switching operation tool for selecting the turning state is provided in the turning operation tool for turning operation as in the present invention, while operating while holding the turning operation tool with, for example, the right hand,
When performing a switching operation between a turning state (a gentle turning state and a rapid turning state), the switching operation tool can be operated with the right hand holding the turning operation tool. Thus, it is not necessary to operate the switching operation tool with the left hand while holding the turning operation tool with the right hand.

[0007]

As described above, the switching operation can be performed with one hand having the turning operation tool for turning operation, without the need to operate the switching operation tool with the left hand while holding the turning operation tool with the right hand. It became possible to operate the tool and improve the operability of the switching operation of the turning state.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. (1) FIG. 2 shows a combine, 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 transmitted through a belt transmission mechanism (not shown) equipped with a tension clutch to a hydrostatic continuously variable transmission 1. The power transmitted to the input pulley 2 and transmitted from the output shaft 3 of the hydrostatic continuously variable transmission 1 is transmitted to the reaping unit (not shown) at the front of the machine body via the first transmission shaft 4.

Power from the first transmission shaft 4 is transmitted to the second transmission shaft 11 via the first gear 9 and the second gear 10.
A shift gear 14 is slidably fitted to the second transmission shaft 11 by a spline structure, while a high speed gear 16, a medium speed gear 17, and a low speed gear 6 are fixed to a third transmission shaft 15 corresponding thereto. . With the above structure, the shift gear 14 is slid and operated to engage the high-speed gear 7, the medium-speed gear 17, or the low-speed gear 6 that meshes with the high-speed gear 16, and the forward rotation power for straight traveling can be shifted to three stages of high, medium, and low. This forward rotation power is applied to the first transmission gear 19 that meshes with the medium speed gear 17.
Be transmitted to. As described above, the shift gear 14, the high speed gear 7 and the like constitute the gear shift type transmission 13.

A right side gear 21R and a left side gear 21L are relatively rotatably fitted onto a support shaft 20 for supporting the first transmission gear 19, and an input gear 23 of a left and right axle shaft 22 is a left and right side gear 21R, 21L is always occluded. As a result, the right or left side gear 21R, 2
1L is slid on the first transmission gear 19 to engage / separate the first transmission gear 19, and power transmission and transmission interruption operation are performed on the crawler type traveling device 24.
Side clutches 25R and 25L are formed between the left and right side gears 21R and 21L.

(2) Next, description will be given of a structure in which one traveling device 24 is reversely driven to make a super turning turn (corresponding to a sharp turn). As shown in FIG. 2, the third gear 37 that meshes with the high speed gear 16 of the third transmission shaft 15 is fitted onto the fourth transmission shaft 27 so as to be relatively rotatable, and the third gear 37 and the fourth transmission shaft 27 are connected to each other. A reverse clutch 30 (corresponding to a sharp turning mechanism) is provided between them. The second transmission gears 26 are provided on both left and right ends of the support shaft 20.
Bearings R and 26L support the fourth transmission shaft 2
Each of the fourth transmission gears 29 fixed to both ends of
It meshes with the transmission gears 26R and 26L.

As a result, the right side gear 21R or the left side gear 21L is connected to the right or left second transmission gear 26.
When the reverse clutch 30 is engaged and operated with the R and 26L engaged, the power from the high-speed gear 16 is transmitted in reverse to the traveling device 24 while being decelerated by 1/3. In this case, since the other side gears 21R and 21L are engaged with the first transmission gear 19 and are normally driven,
The aircraft makes a super turning turn.

(3) Next, a structure will be described in which one of the traveling devices 24 is driven to rotate in the normal direction at a lower speed than the other to make a gentle turn. As shown in FIG. 2, a small-diameter output gear 28 is fixed to the boss portion of the first transmission gear 19, and a large-diameter third transmission gear 40 is externally fitted to the fourth transmission shaft 27 so as to be relatively rotatable. Three
The transmission gear 40 meshes with the output gear 28. And
The slow swing clutch 12 (corresponding to a slow swing mechanism) is provided between the third transmission gear 40 and the fourth transmission shaft 27.

As a result, the right or left side gear 21
When the slow turning clutch 12 is engaged and operated while the R and 21L are engaged with the right or left second transmission gears 26R and 26L, the forward drive power for straight traveling transmitted to the first transmission gear 19 is outputted. , Through the third transmission gear 40, the slow swing clutch 12, the fourth transmission shaft 27, the fourth transmission gear 29, and the right or left second transmission gear 26R, 26L as a normal rotation power reduced to 1/3. It is transmitted to one of the traveling devices 24. In this case, the other side gears 21R and 21L are engaged with the first transmission gear 19 and are normally driven at a predetermined speed, so that the machine body slowly turns due to the speed difference between the left and right traveling devices 24.

(4) Next, the left and right side gears 21R, 2
Hydraulic cylinders 31R, 31 that perform a slide operation of 1L
The structure for supplying the hydraulic oil to the L, gently turning and reverse rotation clutches 12 and 30 will be described. As shown in FIG. 1, the hydraulic oil from the pump 32 passes through the first switching valve 33 to the hydraulic cylinders 31R and 31L for the left and right side gears 21R and 21L.
The oil passage 34 from the side surfaces of the hydraulic cylinders 31R, 31L is connected to a second switching valve 35 (corresponding to switching means) for the slow swing and reverse rotation clutches 12, 30. Further, in the oil passage 34, the slow turning and reverse rotation clutches 12, 30 are provided.
Is connected to the variable relief valve 36. An operation lever 39 (corresponding to a turning operation tool) for turning operation is provided in the control section of the machine body, and the operation lever 39 and the first switching valve 3 are provided.
3 and the variable relief valve 36 are mechanically linked via linkage mechanisms 41 and 42.

The second switching valve 35 includes a slow turning position 35a for supplying hydraulic oil to the slow turning clutch 12 and a reverse rotation clutch 3
It is an electromagnetic operation type for switching to a super-trusted turning position 35b for supplying hydraulic oil to 0, and a gentle turning position 35 by a spring 35c.
It is urged by a. A push-on push-off type switching button 5 (corresponding to a switching operation tool) is provided at the upper end of the operating lever 39. When the switching button 5 is pushed off, the second switching valve 35 turns gently. Position 3
5a and the push-on operation of the switching button 5, the switching button 5 and the second switching valve 35 are electrically operated so that the second switching valve 35 is operated to the super-trust turning position 35b. It is linked.

(5) With the above structure, the operation lever 39
Push-off operation of the switching button 5 of the second switching valve 3
5 is operated to the gentle turning position 35a. When the operation lever 39 is operated to the neutral position N in this state, the first switching valve 33 is also operated to the neutral position, and the left and right hydraulic cylinders 31R,
31L contracts, and the left and right side gears 21R and 21L are in mesh with the first transmission gear 19. As a result, the normal rotation power transmitted to the first transmission gear 19 is transmitted to the left and right traveling devices 24, the left and right traveling devices 24 are driven at the same speed, and the machine body travels straight.

Next, when the operating lever 39 is operated from the neutral position N to the right first turning position R1 or the left first turning position L1, only the first switching valve 33 is operated and the hydraulic cylinder 3 is operated.
By 1R or 31L, the right or left side gears 21R and 21L, which are in mesh with the first transmission gear 19, are separated from the first transmission gear 19 via the right or left operation portion 18, and the right or left side gears 21R and 21L are separated. 2 It engages with the transmission gears 26R and 26L.

In this case, since the variable relief valve 36 is in the fully open state and the slow swing clutch 12 is in the disengaged state,
The transmission to the right or left traveling device 24 is cut off (the transmission of the side clutch 25R or 25L is cut off),
The aircraft slowly turns to the right or left. And
The sequence valve 38 provided in the oil passage 34 supplies the pressure required for the right or left side gear 21R, 21L to completely mesh with the right or left second transmission gear 26R, 26L. It is for securing 31L.

Next, the operating lever 39 is moved from the right or left first turning position R1, L1 to the right or left second turning position R2, L.
When you move to 2, the right or left side gear 21R, 2
The variable relief valve 36 is gradually operated from the fully opened state to the closed side in a state in which 1L is engaged with the right or left second transmission gears 26R and 26L, and the second switching valve 35 is operated to the gentle turning position 35a. Go away. As a result, the loose swing clutch 1
2 starts to operate, the right or left traveling device 24 is gradually driven to rotate at a low speed in the forward direction, and the body slowly turns to the right or left. Then, at the right or left second turning position R2, L2 of the operation lever 39, the slow turning speed becomes maximum (above,
Equivalent to a gentle turning state).

(6) Next, the switching button 5 of the operating lever 39 is pushed on to operate the second switching valve 35 to the super-trust turning position 35b. In this state, the operation lever 39
When the control lever 39 is operated to the neutral position N, it goes straight as described above. When the operation lever 39 is operated from the neutral position N to the first turning position R1 or L1 on the right or left, the right or The transmission cut-off state of the left side clutch 25R, 25L appears.

Next, the operating lever 39 is moved from the right or left first turning position R1, L1 to the right or left second turning position R2, L.
When you move to 2, the right or left side gear 21R, 2
In the state where 1L is engaged with the right or left second transmission gears 26R, 26L, and the second switching valve 35 is operated to the super trust turning position 35b, the variable relief valve 36 is opened from the fully opened state as described above. It is gradually operated toward the closed side. This allows
The right or left traveling device 2 after the reverse clutch 30 starts to operate.
4 is gradually driven in the reverse direction, and the aircraft makes a super turning turn to the right or left. Then, at the right or left second turning position R2, L2 of the operating lever 39, the reverse rotation speed becomes maximum (the above is equivalent to the super-trust turning state).

[Other Embodiments] In the configuration shown in FIG. 1, the switching button 5 is not a push-on push-off type but a return urging type, and when the switching button 5 is pushed, the second switching valve is operated. It may be configured such that when the switch 35 is operated to the super-specific turning position 35b and the hand is released from the switching button 5, the switching button 5 returns and the second switching valve 35 is operated to the gentle turning position 35a. In the return-bias type switching button 5 described above, the operation lever 39 is moved to the right or left second turning position R2, L.
The second switching valve 35 may be configured so as not to be operated to the super-trusted turning position 35b unless the switching button 5 is pressed while being operated to 2.

Instead of the changeover button 5, a toggle type changeover switch (not shown) (corresponding to a changeover operation tool) may be provided on the operation lever 39. In the configuration shown in FIG. 2, instead of the reverse rotation clutch 30, a side brake (not shown) for braking the traveling device 24 on one side to turn the airframe in a solid state.
The present invention can also be applied to a work vehicle of the type equipped with as a rapid turning mechanism. And, the present invention relates to the above-mentioned publication (JP-A-4-3
As shown in FIG. 2 of Japanese Patent No. 21473), it can also be applied to a work vehicle of a type in which a gentle turning state and a sharp turning state are selected by a gear switching operation.

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 hydraulic circuit diagram of left and right side gear hydraulic cylinders, a first switching valve, a second switching valve, a variable relief valve, and the like.

FIG. 2 is a schematic diagram showing a transmission structure in a mission case.

[Explanation of symbols]

 5 Switching operation tool 12 Slow turning mechanism 24 Traveling device 30 Rapid turning mechanism 35 Switching means 39 Turning operation tool

Claims (1)

[Claims] 1. A slow turning mechanism (12) for turning a vehicle body by causing a speed difference between a pair of left and right traveling devices (24), and a pair of left and right traveling devices (24) more than the slow turning mechanism (12). A sudden turning mechanism (30) for causing a large speed difference to turn the vehicle body; a slow turning state in which the slow turning mechanism (12) is operable and the quick turning mechanism (30) is stopped; Switching means (3) capable of selective switching operation to a sudden turning state in which the mechanism (30) is operable and the slow turning mechanism (12) is stopped.
5) In addition, a single turning operation for turning the aircraft to the right or left by operating the slow turning mechanism (12) or the sharp turning mechanism (30) by artificially operating to the right or left A work in which the turning operation tool (39) is provided with a switching operation tool (5) which is provided with a tool (39) and artificially selectively switches the switching means (35) between a gentle turning state and a rapid turning state. Vehicle turning operation structure.