JPH1054450A - Working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply constitute a working vehicle capable of stopping the vehicle body from being moved by its own weight even if the vehicle body is stopped on a slope. SOLUTION: A braking device 23 capable of freely switching the braking state for making braking force act on a traveling device and the non-braking state for releasing braking force is provided, a speed change operating means for changing the speed of the traveling device 1 is provided, an energizing means 31 for energizing a part to be switched and operated 23A of the braking device 23 to the braking side is provided, and an operating mechanism 32 for mechanically switching and operating the part to be switched and operated 23A is so provided that the part to be switched and operated 23A may be positioned in the non-braking side against energizing force of the energizing means and the braking device 23 may be in the non-braking state when the speed change operating position of the speed change operating means is in the traveling position, and that the part to be switched and operated 23A may be positioned in the braking side by energizing force and the braking device 23 may be in the braking state when the speed change operating position is positioned in the neutral position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift operation for changing the speed of a traveling device by providing a braking device which can be switched between a braking state in which a braking force is applied to the traveling device and a non-braking state in which the braking force is released. The present invention relates to a work vehicle provided with a means.

[0002]

2. Description of the Related Art Conventionally, the above working vehicle is disclosed in
There is a combine disclosed in Japanese Patent No. 4956, and in this conventional technique, when the shift lever is set to a neutral position,
Pressure oil is supplied to the stop brake and a braking force acts on the traveling system.

[0003]

As described above, when the shift lever is operated to the neutral position and the pressure from the hydraulic pump is applied to the braking device to obtain a braking force, the operation is performed while the engine is running. When the vehicle is stopped, such as when the vehicle is stopped, a braking force always acts on the traveling system to prevent the vehicle from moving due to its own weight on the slope, but a dedicated valve or oil for controlling the braking device is used. There is room for improvement because the configuration is likely to be complicated due to the need for roads and the like.

[0004] An object of the present invention is to provide a simple construction of a work vehicle capable of preventing movement of a vehicle body due to its own weight even when the vehicle body is stopped on a slope.

[0005]

[Means for Solving the Problems]

[Structure] The characteristic structure of the invention according to claim 1 is characterized in that, in the work vehicle described at the beginning, an urging means for urging a switched operation portion of the braking device toward a braking side is provided, and a speed change operation of the speed change operation means is provided. When the position is in the traveling position, the switched operation portion is located on the non-braking side in a state opposing the urging force of the urging means, the braking device is in the non-braking state, and the shift operation position is in the neutral position. In some cases, an operating mechanism is provided for mechanically switching the switched operation unit so that the switched operation unit is positioned on the braking side by the urging force and the braking device is in a braking state. is there.

According to a second aspect of the present invention, in the first aspect of the present invention, the operating mechanism includes an operating member linked to a switched operating portion of the braking device, and a shifting operation of the shifting operation means. A cam mechanism for operating the operating member in accordance with a shift operation of the shift operating lever, the cam mechanism having a cam surface on the shift operating lever side and the operating member side. A cam follower is provided separately, and a concave portion for dropping the cam follower is formed on the cam surface when the shift operation position is at a neutral position.

According to the first aspect of the present invention, when the switched operation portion of the braking device is mechanically switched in a state where the shift operation position of the shift operation means is at the neutral position, the switched operation portion is changed. The brake device goes to the non-braking side while resisting the biasing force of the biasing means, and the braking device is in the non-braking state in a state where the shift operation position is the traveling position, so that the vehicle body is allowed to travel. When the switchover operation section is mechanically switched while the gearshift operation position is in the traveling position, the switchover operation section moves toward the braking side by the urging force, and the braking device is moved in a state where the gearshift operation position is in the neutral position. Is in a braking state, and the movement of the vehicle body is prevented.

That is, in the structure of the first aspect, since the braking device is controlled by the mechanical switching operation of the switched operation portion of the braking device as described above, a dedicated valve is used as compared with the case where the braking device is switched by hydraulic pressure. No oil passages are required, and the structure can be simplified.

When the shift operation position is operated from the traveling position side to the neutral position side, the shift operation position is operated by the urging force.
Conversely, when the shift operation position is operated from the neutral position side to the traveling position side, since the operation is performed against the urging force, the operation force does not become too light, and the disguise operation position is accurately adjusted to the target traveling position. It is easy to set and the usability can be improved.

According to the configuration of claim 2, the following operation can be obtained. When the shift operation position is at the neutral position, the cam follower of the cam mechanism has fallen into the concave portion of the cam surface. When the shift operation lever is operated to the traveling position side from this state, the cam follower rides on the cam surface portion connected to the concave portion while resisting the urging force of the urging means. The switched operation section is operated to be positioned on the non-braking side. As a result, the braking device is brought into a non-braking state in a state where the shift operation position is at the traveling position, and the traveling of the vehicle body is permitted.

When the shift operation position is at the traveling position,
The cam follower rides on a portion connected to the concave portion of the cam surface. When the shift operation lever is operated to the neutral position side from this state, the cam follower falls into the concave portion of the cam surface due to the urging force, and along with the fall, the operating member operates the switched operating portion of the braking device to move the brake side. Position. As a result, the braking device is brought into the braking state in a state where the shift operation position is at the neutral position, and the movement of the vehicle body is prevented.

That is, according to the structure of the second aspect, in addition to the same effect as the operation of the first aspect, the operation mechanism can be simplified and a reliable operation can be realized.

According to the first aspect of the present invention, the vehicle body can be prevented from moving due to its own weight even when the vehicle body is parked on a slope, and a work vehicle with good operability in disguise operation can be easily configured. I was able to.

According to the second aspect of the present invention, even when the vehicle body is stopped on the slope, the movement of the vehicle body due to its own weight can be prevented.
In addition, a work vehicle with good operability of the disguise operation can be configured more easily.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a cutting pre-processing unit B is connected to a front portion of a vehicle body A having left and right crawler traveling devices 1, and a control unit C is disposed at a position parallel to the right side of the pre-cutting processing unit B. Then, a combine (an example of a work vehicle) is configured by mounting the threshing device 2 and the Glen tank 3 on the vehicle body A.

The pre-cutting processing unit B includes a raising device 4 for raising the grain stalk, a cutting blade 5 for cutting the root of the raised grain stalk,
A transport device 6 for feeding the harvested grain culm to the threshing device 3 is provided, and a driving seat 7, a shift operation lever 8 for setting a traveling speed of the vehicle body A, A steering lever 9 for setting a traveling direction is disposed, an engine 10 is disposed below the driver's seat 7, and a transmission transmission case D is disposed at a central position on the left and right of the front of the vehicle body.

As shown in FIGS. 2 and 3, an input pulley 12 to which power from an engine 10 is transmitted via an endless belt 11 is provided at an upper portion of the transmission case D, and the transmission power is synchronized with the shifting power from the transmission case D. And an output pulley 13 for taking out the generated power, a sprocket 1S for driving the left and right crawler traveling devices 1 is provided at a lower portion, and a steering cylinder case 14 is provided at a front surface. Also,
The transmission case D is provided with a rotary type shift valve 15 inside, and an operation arm 15A of the shift valve 15 and an arm 8A of the shift operation lever 8 are linked via a rod 16. A steering valve 17 is provided, and an operation arm 17A of the steering valve 17 and an arm 9A of the steering lever 9 are linked via a wire 18 (shift operation means 39 with the shift lever 8, the rod 16, etc.). Make up).

As shown in FIG. 2, inside the transmission case D, a gear type auxiliary transmission E for shifting the power from the input shaft 21 connected to the input pulley 12, and three forward-moving clutches A main transmission G having CP1, CP2, CP3 and one reverse clutch CP4;
A steering clutch H capable of selectively transmitting power from the speed change system to the left and right crawler traveling devices 1 and, when the sleeve 22 of the steering clutch H is operated to the disengagement side, traveling on the disengagement side. Brake mechanism 23 for applying a braking force to the system
(An example of a braking device) and a gear transmission for transmitting power from the steering clutch H to the drive sprocket 1S and transmitting power from the input shaft 21 to the drive shaft 19 of the output pulley 13. K is provided. Further, the auxiliary transmission E is linked so that it can be switched by operating a lever (not shown), and the main transmission G selectively operates the transmission clutches CP1 to CP4 by supplying and discharging the pressure oil by the transmission valve 15. The traveling speed can be switched between three forward speeds and one reverse speed (see the hydraulic circuit diagram of FIG. 5), and the steering clutch H is a ram cylinder having left and right sleeves 22 built into the cylinder case 14. It is configured to be operated by transmitting an operation force from the steering arm 25 (see FIG. 3) via the steering arm 26.

As shown in FIGS. 3 and 4 (a) and (b),
A dedicated operation arm 23A (an example of a switched operation unit) for externally performing a braking operation on the left brake mechanism 23 is provided on the outer surface of the brake mechanism 23, and the brake mechanism 23 is provided with a brake provided on the control unit C. The brake pedal 27 is operated so that the brake operation is performed by depressing the pedal 27.
Arm 27A and the operation arm 23A of the brake mechanism 23
When the vehicle body is to be stopped for a long time, the operation lever 29 provided on the brake pedal 27 is artificially operated to the braking side to hold the vehicle in the braking position. The brake mechanism 23 is configured to be able to be used for a parking brake while maintaining the braking state.

A pin 40A and a slot 40 are provided between the operation arm 23A and the end of the wire 28 on the operation arm 23A side.
A first coil spring 31 for urging the operation arm 23A toward the braking side with the interposition of the accommodating mechanism 40 in combination with
When the shift operation position of the shift operation lever 8 is at any one of three forward speeds F1, F2, F3 and one reverse speed R, the operating arm 23A is connected to the first coil spring 31. When the shift mechanism is in the neutral position N when the brake mechanism 23 is in the non-braking state while being positioned on the non-braking side against the urging force of the operating arm 23A,
There is provided a first operating mechanism 32 for mechanically switching the operating arm 23A so that the brake arm 23 is in a braking state by being positioned on the braking side by the urging force.

The first operating mechanism 32 includes an operating arm 23
Swing arm 34 linked to wire A via wire 33
(An example of an operation member) and a cam plate 8 </ b> A provided on the base end side of the shift operation lever 8.
A cam mechanism 35 for operating the swing arm 34 in accordance with the speed change operation is provided, and the cam mechanism 35 is provided with a cam surface 36 on the cam plate 8A and the swing end of the swing arm 34.
And the cam follower 37 are separately provided, and when the gear shift operation position reaches the neutral position N, a concave portion 36a for dropping the cam follower 37 is formed on the cam surface 36.

In the traveling position, the brake pedal 27
The operation arm 2 so that the brake operation by the
A second coil spring 38 having a larger spring constant than the first coil spring 31 is interposed between the wire 3A and the wire 33A.

As shown in FIG. 5, the shift valve 15 is in a neutral position N, a first forward speed position F1, and a second forward speed position F.
2. It is configured to be freely operable at the forward third speed position F3 and the reverse position R, and supplies pressure oil from the hydraulic pump P to each of the shift clutches CP1 to CP4 via the accumulator 41 during shifting. Transmission clutch CP1
Shock at the time of entering operation of CP4 is reduced.

[Alternative Embodiment] The present invention can be applied to a working vehicle such as an agricultural machine or a construction machine other than the combine.

[Brief description of the drawings]

FIG. 1 is a side view of a combine.

FIG. 2 is a front view schematically showing a transmission system of a transmission case.

FIG. 3 is a schematic front view of a mission case.

4A is a diagram showing an operation state of the operation mechanism when the shift position is a neutral position. FIG. 4B is a diagram showing an operation state of the operation mechanism when the shift position is a traveling position.

FIG. 5 is a hydraulic circuit diagram for controlling traveling speed and a cylinder mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Traveling device 8 Shift lever 23 Braking device 23A Switched operating part 31 Biasing means 32 Operating mechanism 34 Operating member 35 Cam mechanism 36 Cam surface 36a Cam surface portion 37 Cam follower 39 Gear shifting operating means

Claims (2)

[Claims] An operation in which a braking device that can be switched between a braking state in which a braking force is applied to a traveling device and a non-braking state in which the braking force is released is provided, and shift operation means for shifting the traveling device is provided. A vehicle, further comprising: urging means for urging the switched operation portion of the braking device toward the braking side, wherein when the speed change operation position of the speed change operation means is at the traveling position, the switched operation portion is configured to be energized. The switching device is positioned on the braking side by the biasing force when the braking device is in the non-braking state by being located on the non-braking side in a state against the biasing force of the means, and the shift operation position is in the neutral position. A work vehicle provided with an operation mechanism for mechanically switching the switched operation unit so that the braking device is brought into a braking state. 2. The operating mechanism according to claim 1, wherein the operating mechanism is provided between an operating member linked to a switched operating portion of the braking device and a shift operating lever of the shift operating means in accordance with a shift operation of the shift operating lever. A cam mechanism for operating an operation member is provided, and this cam mechanism is provided with a cam surface and a cam follower distributed to the shift operation lever side and the operation member side, and when the shift operation position becomes a neutral position. 2. The work vehicle according to claim 1, wherein a concave portion for dropping the cam follower is formed on the cam surface.