JP3356882B2 - Work vehicle steering means - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention provides a pair of hydrostatic continuously variable transmissions for individually driving a pair of left and right traveling devices, respectively. The present invention relates to a work vehicle steering means in which a single steering operation lever and a single shift operation lever are respectively linked.

[0002]

2. Description of the Related Art Conventionally, in a working vehicle such as a combine or the like that performs steering and shifting with this type of structure, a shift operating portion of a double hydrostatic continuously variable transmission is operated in accordance with the operation of a shift operating lever. The same displacement operation amount is provided, and a positive operation amount is provided to the shift operation portion of one of the hydrostatic continuously variable transmissions in accordance with the operation direction of the steering operation lever, and the other is provided. The hydrostatic stepless transmission has been linked to give a negative operation amount to the shift operation section.

[0003]

However, in the above-mentioned conventional structure, the right steering and the left steering during forward running are the same as those in which the operating direction of the steering operating lever and the actual steering direction are matched. Even if it does, since the operation direction of the steering operation lever and the actual steering direction are opposite when the vehicle is traveling backward, there is a possibility that the steering operation may be erroneously performed when traveling backward. SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and is directed to a steering of a work vehicle capable of making the operating direction of a steering operating lever coincide with the actual steering direction in both forward and backward traveling. The purpose is to provide means.

[0004]

In order to achieve the above object, a steering means for a working vehicle according to the present invention has the above-mentioned structure, wherein each of the shift operation sections, the steering operation lever, Based on the forward operation of the shift operation lever,
A state in which the shift operation portion is operated in a forward direction with respect to an operation direction of the steering operation lever, and a state in which the steering operation lever is operated in a reverse direction based on a backward operation of the shift operation lever In cooperation with the operation direction change transmission means that can be switched to the state of operating the speed change operation unit in the reverse direction, the operation direction change means is a transmission switching clutch,
One of the forward rotation transmission gear group and the reverse rotation transmission gear group is configured to be selected and interlockedly connected to the steering operation lever and the shift operation section. Further, the transmission switching clutch may be configured to disconnect the interlocking connection between the steering operation lever and the shift operation unit when the shift operation lever is operated to a neutral position. Further, when the steering operation lever is being operated in one direction, the transmission switching clutch of the operation direction changing transmission means linked to the steering operation lever is connected to the steering operation lever. An interlocking connection between the operation lever and the shift operation unit may be disconnected. The operation and effect of this characteristic configuration are as follows.

[0005]

The shift operation section and the steering operation lever are operated in the forward direction with respect to the operation direction of the steering operation lever based on the forward operation of the shift operation lever. And a state in which the shift operation portion is operated in a direction opposite to the operation direction of the steering operation lever based on the reverse operation of the shift operation lever via the operation direction change transmission means. The operation direction changing means is linked with a transmission switching clutch, and one of a forward rotation transmission gear group and a reverse rotation transmission gear group is selected as a steering operation lever and a speed change operation unit in an interlocking manner. It is configured so that even if the operating direction of the steering operation lever is forward,
Even when the vehicle is moving backwards, it will match and will match the maneuvering sensation. Further, if the transmission switching clutch is configured to disconnect the interlocking connection between the steering operation lever and the speed change operation unit when the speed change operation lever is operated neutral, the speed change operation lever is neutralized. Sometimes, even if the steering operation lever is operated by mistake, the shift operation portion of the hydrostatic continuously variable transmission is not unduly operated,
Since the vehicle is maintained in the neutral state, there is no possibility that the vehicle is started unfairly.
Further, when the steering operation lever is being operated in one direction, the transmission switching clutch of the operation direction changing transmission means in the other direction linked to the steering operation lever includes a steering operation lever, If the interlocking connection with the speed change operation unit is cut off, it is possible to perform a pivot turn in which one of the left and right traveling devices is driven while only the other is driven and the other is driven.

[0006]

Thus, according to the present invention, when the forward / backward operation is performed by the speed change operation lever, the actual steering corresponding to the operation direction of the steering operation lever at the time of forward movement and the operation at the time of reverse movement are performed. The actual steering corresponding to the operation direction of the steering operation lever is the same as the actual steering, and the problem that the steering direction of the steering operation lever is steered reversely to the operation direction when the vehicle is moving backward is solved, Steering that matches the pilot's steering sensation can now be performed appropriately.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 shows a combine as an example of the work vehicle. This combine is equipped with a pre-cutting unit 3, a threshing unit 4, a grain storage unit 5, a control unit 6, a driving unit 7, and the like mounted on a body frame 2 supported by a pair of left and right crawler traveling devices 1, 1. It is configured.

As shown in FIG. 1, a pair of hydrostatic stepless transmissions (hereinafter, referred to as HSTs) are used to independently drive the pair of left and right crawler traveling devices 1 and 1 independently.
HSTs 8 and 8 are respectively driven by power from the driving unit 7. Then, as shown in FIG.
And a steering operation lever 10 that can freely swing left and right are arranged in the steering unit 6, and the trunnion shaft 1 of a variable displacement hydraulic pump as a shift operation unit of each of the HSTs 8 and 8 is provided.
The shift operation levers 9 and the steering operation lever 10 are linked to each other.

More specifically, as shown in FIG.
Arms 12,1 are attached to the trunnion shafts 11,8,8.
2 are integrally provided, and the arms 12, 12 and the speed change operation lever 9 are interlockingly connected via a pair of first release wires 13, 13. And the steering operation lever 1
0, the second release wires 16, 1 are operated such that the input operation arms 15, 15 of the pair of operation gear devices 14, 14 as operation direction change transmission means are respectively operated in opposite directions.
6 are linked. As shown in FIG. 1 to FIG.
7 and 17 are pivotally attached to plates 18 and 18 interposed between the first release wires 13 and 13, respectively. The operation gear devices 14 and 14 are configured by a gear mechanism housed in an outer case 19. That is, the operation gear device 14 includes:
A first shaft 20 that rotates integrally with the input operation arm 15;
A second shaft 21 that rotates integrally with the output operation arm 17,
The first shaft 20 and the third shaft 22 disposed in parallel with the second shaft 21 are rotatably supported, respectively.
A first gear 23 and a second gear 24 are provided side by side on a first shaft 20 in a freely rotatably supported state. A third gear 25 is mounted on a second shaft 21.
And the fourth gear 26 are arranged side by side so as to rotate integrally.
A fifth gear 27 that is always meshed with the second gear 24 and the fourth gear 26 is provided on the third shaft 22 so as to rotate integrally. The first gear 23 and the third gear 25 are always meshed with each other, and the first shaft 20 has the axial direction P
A shift member 28 is spline-fitted slidably along the axis. By shifting the shift member 28, one of the first gear 23 and the second gear 24 is selected, and the first shaft 20 First selected so that it can rotate together
One of the gear 23 and the second gear 24 and the shift member 28 constitute a transmission switching clutch C that is engaged and connected.
The shift operation of the shift member 28 is performed by the electric actuator 29, and the drive control of the electric actuator 29 is performed by the control device 30 described later.

Further, as shown in FIG. 1, the first release wires 13 for connecting the speed change operation lever 9 and the plates 18 are connected to the first release wires 1 respectively.
An elastic mechanism 31 for buffering the pushing and pulling forces of
31 are provided. That is, the elastic mechanism 31 is provided with two compression coil springs 3 arranged in parallel in the push-pull direction.
And a first release wire 1 connected to the disk body 35 and the disk body 18 disposed inside the rigid case 34 and inserted between the compression coil springs 32 and 33.
3 are integrally connected to each other while penetrating the bottom of the rigid case 34. With this structure,
The elastic mechanism 31 absorbs the displacement of the plate 18 due to the operation of the steering operation lever 10 so that the shift operation lever 9 is not affected by the displacement. Then, as shown in FIG. 1, the operation lever position detecting potentiometer 36 for detecting whether the speed change operation lever 9 is operated forward or backward is operated by turning the speed change operation lever 9. It is provided so that it can be detected in conjunction with the moving shaft.
The detection signal of the operation lever position detection potentiometer 36 is input to the control device 30 mounted on the body, and based on the input signal, whether the shift operation lever 9 is neutral or the forward operation is being operated. Alternatively, the control device 30 determines whether the reverse operation is being performed. And
On the basis of the determination result, when the forward operation is being performed, the respective electric actuators 29, 29 are connected so that the shift members 28 of the left and right operation gear devices 14, 14 are connected to the first gear 23. When the reverse is operated, the respective electric actuators 29, 29 are operated such that the shift members 28 of the left and right operation gear devices 14, 14 are connected to the second gear 24. Will be.

Thus, when the steering operation lever 10 is operated, for example, rightward during forward movement, the first gear 23 in the right-handed operation gear device 14 interlocks with the pulling operation of the second release wire 16. Then, the plate body 18 is displaced through the third gear 25, and the HST 8 on the right side is decelerated to steer to the right. In the left HST 8, the second release wire 16 of the left leg is loosened, so that the left gear operating gear device 14 and the left HST 8 are maintained without being operated. When the steering operation lever 10 is operated to the left, the reverse operation is performed. On the other hand, when the shift operation lever 9 is being operated in reverse, the control device 30 determines that the vehicle is in reverse, and based on the determination result, the electric actuator 2
By operating the gears 9 and 29, the first gear 23 and the third gear are brought into the interlocked state, and the second gear and the fourth gear are brought into the interlocked state via the fifth gear 27 as a reverse gear. This allows
When the steering operation lever 10 is steered to the right during backward movement, the right-hand plate 18 is displaced, and the right-hand HST 8 is decelerated to the right. As a result, the operating direction of the steering operation lever 10 and the steering direction coincide with each other regardless of whether the vehicle is moving forward or backward.

In the control device 30, when the shift operation lever 9 is not in the forward operation or the reverse operation, that is, when the shift operation lever 9 is located in the neutral operation position corresponding to the traveling stop state, the operation lever position detection potentiometer 36 Based on the signal output in the detection range N corresponding to the neutral position, the shift members 28, 28 of the left and right operation gear devices 14, 14 are both shifted by the first gear 23 and the second gear 2.
4 to be operated to a neutral position that is not linked to any of the above. That is, when the shift operation lever 9 is in the neutral position, even if the steering operation lever 10 is operated, the vehicle does not run unjustly.

[Alternative Embodiment] In the above embodiment, the left and right operating gear devices 14,
The shift members 28 and 28 in 14 are both connected to the first gear 23 when the shift operation lever 9 is moved forward, and are connected to the second gear 24 when the reverse operation is performed. In addition to the example, FIG.
As shown in FIG. 3, a detecting means 37 for detecting the operation direction of the steering operation lever 10 is provided.
Is operated to the right, the control device 30 moves the shift member 28 of the left-handed operation gear device 14 to either the first gear 23 or the second gear 24 based on the detection signal input from the detection means 37. Alternatively, it may be controlled so that it is operated to a neutral position that is not interlocked and connected.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing a speed change and steering operation system of a combine;

FIG. 2 is a schematic explanatory view showing an operation direction change transmission means.

FIG. 3 is a schematic explanatory view showing a main part of an operation structure of an operation direction changing transmission means during forward movement (a) and a main part of an operation structure of an operation direction change transmission means during backward movement (b).

FIG. 4 is an overall side view showing the combine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Traveling device 8 Hydrostatic stepless transmission 9 Shift operation lever 10 Steering operation lever 11 Shift operation part 14 Operation direction changing transmission means C Transmission switching clutch

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shiro Okuda 64 Ishizukita-cho, Sakai-shi, Osaka Kubota Sakai Works Co., Ltd. (56) References JP-A-50-19119 (JP, A) JP-A-51- 25221 (JP, A) JP-A-1-301474 (JP, A) JP-A-48-44337 (JP, Y1) JP-A-49-38826 (JP, Y1) (58) Fields investigated (Int. ⁷ , DB name) B62D 11/00

Claims (3)

(57) [Claims] 1. A pair of hydrostatic stepless transmissions (8) and (8) for individually driving a pair of left and right traveling devices (1) and (1), respectively, and each of the hydrostatic stepless transmissions is provided. Transmission operating parts (11), (1) of transmissions (8), (8)
1) A work vehicle steering means in which a single steering operation lever (10) and a single shift operation lever (9) are linked to each other. ), (11) and the steering operation lever (10) with respect to the operation direction of the steering operation lever (10) based on the forward operation of the speed change operation lever (9). The shift operation unit (11) in the forward direction,
Based on the state of operating the (11) and the reverse operation of the shift operating lever (9), the shift operating section (11) is operated in a direction opposite to the operating direction of the steering operating lever (10). , (11) are linked via operation-direction changing transmission means (14), (14) that can be switched to the state in which the operation direction is changed, and the operation-direction changing means (14) is operated by a transmission switching clutch (C). One of a forward transmission gear group and a reverse transmission gear group is selected and connected to the steering operation lever (10) and the speed change operation sections (11) and (11) in an interlocked manner. The steering means of the working vehicle that has been done. 2. When the shift operating lever (9) is operated to a neutral position, the transmission switching clutch (C) is connected to the steering operating lever (10) and the shift operating section (11).
The steering means for a working vehicle according to claim 1, wherein the interlocking connection with (11) is disconnected. 3. When the steering operation lever (10) is being operated in one direction, the steering operation lever (1) is operated.
A transmission switching clutch (C) of the operation direction changing transmission means (14) linked in the other direction is linked to the steering operation lever (10) and the speed change operation unit (11). 3. The steering means for a working vehicle according to claim 1, wherein the steering wheel is cut off.