JP2011230767A - Working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a working vehicle provided with right and left brakes for right and left running devices and a PTO shaft, in which a machine body is securely stopped when an operator performs a stepping operation of right and left brake pedals.SOLUTION: In the case that a stepping operation is performed to the right and left brake pedals, right and left actuators are actuated to the braking sides of the right and left brakes. When the stepping operation of the right and left brake pedals is performed and the right and left actuators are actuated to the braking sides of the right and left brakes, in the case that a PTO clutch is in a conduction state, it is operated to a shielding state, and thereafter, when the right and left brake pedals are subjected to a returning operation, the right and left actuators are retained to the braking sides of the right and left brakes, and further, the PTO clutch which has been operated to the shielding state is operated to the conduction state.

Description

  The present invention relates to a work vehicle equipped with right and left brakes for right and left traveling devices.

In a work vehicle, for example, as disclosed in Patent Document 1, artificially operated right and left brake pedals (12R and 12L in FIGS. 1 and 10 of Patent Document 1), right and left rear wheels ( Equipped with right and left brakes (11R and 11L in FIG. 1 and FIG. 10 in Patent Document 1) for the traveling device) (2 in FIG. 1 of Patent Document 1), and the right brake pedal is stepped on When the right brake is operated to the brake side and the left brake pedal is stepped on via the linkage mechanism (FIG. 1 of FIG. 1 and FIG. 10 of FIG. 10), the linkage mechanism (FIG. 1 and FIG. 10), the left brake is operated to the braking side.
As a result, when the vehicle stops straight, the driver depresses the right and left brake pedals and operates the right and left brakes to the braking side to stop the aircraft. For example, when turning to the right, the driver can steer the front wheel to the right and simultaneously depress the right brake pedal and operate the right brake to the braking side to make a small turn to the right. .

In Patent Document 1, a hydraulic cylinder (FIGS. 1 and 10 in Patent Document 1) is connected to a linkage mechanism (14 in FIGS. 1 and 10 in Patent Document 1) that connects the right and left brake pedals to the right and left brakes. 13R, 13L), for example, when turning right, when the driver steers the front wheel to the right, hydraulic oil is supplied to the right hydraulic cylinder, and the right hydraulic cylinder contracts, The right brake is configured to be operated to the braking side.
Thus, for example, when turning to the right, if the driver steers the front wheel to the right, the right brake is automatically operated to the braking side without stepping on the right brake pedal. It is possible to make a small turn to.

JP-A-5-262151

  When stopping when going straight, when the driver depresses the right and left brake pedals and operates the right and left brakes to the braking side to stop the aircraft, the pedaling force of the foot, especially for women and the elderly For a driver with a small, it may be considered that the right and left brake pedals are not operated with sufficient foot effort, and the right and left brakes are not sufficiently operated to the braking side.

  The present invention relates to a work vehicle equipped with right and left brakes for right and left traveling devices, in which a driver steps on the right and left brake pedals and operates the right and left brakes on the braking side. The purpose of this is to make the right and left brakes operate sufficiently to the braking side.

[I]
(Constitution)
The first feature of the present invention is that the work vehicle is configured as follows.
Artificially operated right and left brake pedals, and right and left brakes for right and left travel devices. When the right brake pedal is depressed, the right brake is operated to the braking side via the linkage mechanism, and when the left brake pedal is depressed, the left brake is activated via the linkage mechanism. It is configured to be operated to the braking side. A right actuator that can operate the right brake to the braking side and a left actuator that can operate the left brake to the braking side are provided separately from the right and left brake pedals and the linkage mechanism. Automatic turning means for operating the brake on the turning center side to the braking side by the right or left actuator in accordance with the turning operation of the airframe is provided. When the right and left brake pedals are depressed, auxiliary braking means for operating the right and left actuators on the braking side of the right and left brakes is provided.

(Function)
According to the first feature of the present invention, when the right brake pedal is depressed, the right brake is operated to the braking side via the linkage mechanism, and when the left brake pedal is depressed, the linkage mechanism is passed. The left brake is operated to the braking side.
It includes right and left actuators that can operate the right and left brakes on the braking side, and automatic turning means. For example, when the aircraft is turned to the right, the right brake pedal is not depressed. The right brake is automatically operated to the braking side by the right actuator, and a small turn to the right is performed.

According to the first feature of the present invention, when the right and left brake pedals are depressed, the right and left actuators act on the braking side of the right and left brakes.
As a result, the right and left brake pedals are not operated with sufficient foot effort, and the right and left brake pedals are not operated to the braking side with the right and left brake pedals alone. Since the actuator operates on the braking side of the right and left brakes, the stepping operation force of the right and left brake pedals and the operation force of the right and left actuators are transmitted to the right and left brakes, and the right and left brakes are operated. The left brake is fully operated to the braking side.

  In this case, the right and left actuators operate when making a small turn to the right and left as described above, and may be said to be existing ones. Thus, according to the first feature of the present invention, there is no need to provide dedicated right and left actuators for operating the right and left brakes to the braking side when the right and left brake pedals are depressed. The left and right actuators are used for the turning operation of the fuselage and the left and right brake pedals are used for the stepping operation.

When the right and left actuators are provided, for example, as in Patent Document 1, it is conceivable to provide the right and left actuators in a linkage mechanism that connects the right and left brake pedals and the right and left brakes.
However, with this configuration, one end of the right and left actuators is supported by the right and left brake pedals, so that the right and left actuators operate while the right and left brake pedals are stepped on. When the right and left brakes are operated to the braking side, the reaction reaction forces of the right and left actuators must be supported by the right and left brake pedals.
Therefore, if the right and left brake pedals are not operated with sufficient foot pressure, the right and left brake pedals lose the reaction force of the right and left actuators, and the right and left brake pedals return. Therefore, the right and left brakes are not operated sufficiently to the braking side, and the right and left brakes are not fully operated even if the right and left brake pedals are not operated with sufficient foot pressure. It is not a configuration to be operated by.

According to the first aspect of the present invention, the right and left actuators are provided separately from the right and left brake pedals and the linkage mechanism, and one ends of the right and left actuators are supported by the right and left brake pedals. It is not in the state to say.
As a result, the reaction reaction force of the right and left actuators is not applied to the right and left brake pedals, and the operation force of the right and left brake pedals and the operation force of the right and left actuators are separated separately. Independently transmitted to the right and left brakes, the right and left brakes are fully operated to the braking side.

(The invention's effect)
According to the first aspect of the present invention, in a work vehicle equipped with right and left brakes for right and left traveling devices, the right and left brake pedals can be operated even if the pedals are not depressed with sufficient pedal effort. The operation force of the left and right brake pedals and the operation force of the right and left actuators are transmitted to the right and left brakes, and the right and left brakes are sufficiently operated to the braking side. As a result, the stopping performance of the work vehicle was improved.
According to the first feature of the present invention, the right and left actuators are used both when the aircraft is turned, and when the right and left brake pedals are stepped on. Therefore, it became advantageous in terms of simplification of the structure.

[II]
(Constitution)
The second feature of the present invention is that the work vehicle of the first feature of the present invention is configured as follows.
After the right and left brake pedals are stepped on and the right and left actuators are actuated to the braking side of the right and left brakes, the right and left actuators are Auxiliary braking means is configured to maintain the braking side of the right and left brakes.

(Function)
According to the second feature of the present invention, the “action” described in the preceding item [I] is provided in the same manner as the first feature of the present invention, and in addition to this, the following “action” is provided.
According to the second aspect of the present invention, after the right and left brake pedals are stepped on, the right and left actuators act on the braking side of the right and left brakes, and the driver stops the right and left Even if you release your foot from the left brake pedal (even if the right and left brake pedals are returned), the right and left actuators operate on the braking side of the right and left brakes. Even if the right and left brake pedals are inadvertently operated after the aircraft has stopped, the aircraft will not move along a slope or the like.

(The invention's effect)
According to the second feature of the present invention, the “effect of the invention” described in the preceding item [I] is provided in the same manner as the first feature of the present invention. In addition, the following “effect of the invention” is provided. ing.
According to the second aspect of the present invention, the right and left actuators can be used even if the driver lifts his / her foot from the right and left brake pedals (even if the right and left brake pedals are returned) after the aircraft has stopped. However, since the right and left brakes are operating on the braking side and the aircraft does not move along the slopes, the stopping performance of the work vehicle can be improved.

[III]
(Constitution)
The third feature of the present invention is that the work vehicle of the second feature of the present invention is configured as follows.
Auxiliary braking means is configured to operate the right and left actuators from the braking side of the right and left brakes to the braking release side after the set time has elapsed since the start of the aircraft's starting operation. To do.

(Function)
According to the third feature of the present invention, the “action” described in the preceding item [I] [II] is provided in the same manner as the first or second feature of the present invention. In addition, the following “action” is provided. It has.
As described in [II] above, when the aircraft is stopped on a slope or the like and then the right and left brakes are operated to the braking side by the right and left actuators, It is necessary to operate the left actuator to the brake release side of the right and left brakes.
In this case, when the right and left actuators are actuated to the braking release side of the right and left brakes, and the starting power is transmitted to the right and left traveling devices, the right and left actuators are The aircraft may move backward along a slope or the like at the moment when it is actuated to the brake release side of the right and left brakes.

According to the third aspect of the present invention, in the above-described state, when the vehicle is started on a slope or the like, the right and left actuators do not immediately act on the brake release side of the right and left brakes. Therefore, after the starting power is transmitted to the right and left traveling devices, it is possible to obtain a state in which the right and left actuators are actuated to the braking release side of the right and left brakes.
This prevents the right and left actuators from operating on the brake release side of the right and left brakes and avoids the state where the starting power is not transmitted to the right and left traveling devices. The aircraft does not move backward along the slope when starting the aircraft.

(The invention's effect)
According to the third feature of the present invention, the “effect of the invention” described in the preceding paragraphs [I] and [II] is provided in the same manner as the first or second feature of the present invention. The effect of the invention is provided.
According to the third feature of the present invention, when starting the aircraft on a hill or the like, the starting power is transmitted to the right and left traveling devices, and then the right and left actuators are moved to the right and left. It was possible to obtain a state of operating on the brake release side of the brake, and since the aircraft did not move backward along a slope or the like, the start performance of the work vehicle could be improved.

It is a whole side view of an agricultural tractor. It is a whole top view of an agricultural tractor. It is a figure which shows the linkage state of the right and left brake pedal, the right and left brake, and the right and left hydraulic cylinders. It is a figure which shows the flow of control when the right and left brake pedals are stepped on. It is a whole side view of the agricultural tractor in 1st another form of implementation of invention. It is a figure which shows the flow of control when the right and left brake pedals are stepped on in the first alternative embodiment of the invention.

[1]
As shown in FIGS. 1 and 2, a driving unit 3 is formed at the center of the airframe supported by the right and left front wheels 1 and the right and left rear wheels 2 (corresponding to a traveling device). An example is a four-wheel drive agricultural tractor. The power of the engine 4 provided in the front part of the machine body includes a main clutch (not shown), a gear transmission type main transmission (not shown), an auxiliary transmission (not shown), and a rear wheel differential mechanism (see FIG. Is transmitted to the right and left rear wheels 2 via a front wheel transmission device 5 (see FIG. 3) and a front wheel differential mechanism (not shown). To the right and left front wheels 1.

  As shown in FIG. 3, the front-wheel transmission device 5 includes a standard state in which the right and left front wheels 1 and the right and left rear wheels 2 are driven at substantially the same speed, and the right and left front wheels 1 are in the right and left rear. It is configured to be operated in a speed increasing state driven at a higher speed than the wheel 2. When the front wheel transmission 5 is energized to the standard state, the hydraulic oil is supplied by the electromagnetically operated control valve 6 to be operated in the accelerated state, and the working oil is discharged by the control valve 6, the standard state The control valve 6 is operated by the control device 8.

  As shown in FIGS. 1, 2, and 3, a steering handle 7 is provided in front of the driver seat 9 in the driving unit 3, and a pitman arm 10 for steering the right and left front wheels 1 is provided in the lower part of the fuselage. By operating the steering handle 7, the pitman arm 10 is swung left and right, and the right and left front wheels 1 are steered. A potentiometer 13 for detecting the angle of the pitman arm 10 is provided, and a detection value of the potentiometer 13 is input to the control device 8.

As shown in FIG. 3, the control device 8 and the control valve are controlled by the detected value of the potentiometer 13 in the state where the pitman arm 10 is swung within the range of the straight advance position A0 and the right and left set angles A1 from the straight advance position A0. 6, the front wheel transmission 8 is operated to the standard state. In the state where the detected value of the potentiometer 13 swings the pitman arm 10 within the range of the right and left swing limits A2 beyond the right and left set angles A1, the front wheel shift is controlled by the control device 8 and the control valve 6. The device 8 is operated in a speed increasing state.
As a result, when the pitman arm 10 is swung over the right or left set angle A1 (corresponding to a turning operation of the aircraft to the right or left), the front wheel transmission 8 is controlled by the control device 8 and the control valve 6. A small turn to the right or left is performed by the right and left front wheels 1 which are operated in an accelerated state and driven at a higher speed than the right and left rear wheels 2.

[2]
Next, the right and left brake pedals 15 and 16 will be described.
As shown in FIGS. 1 and 2, a clutch pedal 14 for operating the main clutch to transmit and disengage is provided in the lower left portion of the driving unit 3, and right and left brake pedals 15 are provided in the lower right portion of the driving unit 3. 16 are arranged side by side in the left-right direction, and the right and left brake pedals 15, 16 are urged toward the return operation side.

  As shown in FIG. 3, a right brake 17 capable of braking the right rear wheel 2 and a left brake 18 capable of braking the left rear wheel 2 are provided, and the right and left brakes 17, 18 are provided. It is biased to the braking release side. The right brake pedal 15 and the operating arm 17a of the right brake 17 are connected via a connecting rod 19 (corresponding to a connecting mechanism), and the left brake pedal 16 and the operating arm 18a of the left brake 18 are connected to the connecting rod 19. It is connected via (corresponding to a linkage mechanism).

  As a result, as shown in FIG. 3, when the right brake pedal 15 is depressed, the right brake 17 is operated to the braking side via the linkage rod 19, and the right brake pedal 15 is returned. The right brake 17 is operated to the brake release side. When the left brake pedal 16 is depressed, the left brake 18 is operated to the braking side via the linkage rod 19, and when the left brake pedal 16 is returned, the left brake 18 is moved to the braking release side. Operated.

[3]
Next, the right and left hydraulic cylinders 21 and 22 (corresponding to actuators) capable of operating the right and left brakes 17 and 18 to the braking side will be described.
As shown in FIG. 3, a right hydraulic cylinder 21 and a left hydraulic cylinder 22 are supported on the right and left fixing portions 12 of the airframe, and the right hydraulic cylinder 21 and the operating arm 17a of the right brake 17 are Are connected via the linkage rod 20, and the left hydraulic cylinder 22 and the operating arm 18 a of the left brake 18 are connected via the linkage rod 20.

  As shown in FIG. 3, the right and left hydraulic cylinders 21 and 22 are configured as a single-acting type, and are urged to the extension side by an internally mounted spring (not shown), so that the right and left hydraulic cylinders 21, 22 includes electromagnetically operated control valves 23 and 24 for supplying and discharging hydraulic oil. The control valve 23 is operated by the control device 8. When hydraulic oil is supplied from the control valves 23 and 24, the right and left hydraulic cylinders 21 and 22 are contracted, and the right and left brakes 17 and 18 are operated to the braking side. When the working oil is discharged by the control valves 23 and 24, the right and left hydraulic cylinders 21 and 22 are extended, and the right and left brakes 17 and 18 are operated to the brake release side.

  As shown in FIG. 3, the accommodation member 11 having the long hole 11 a is connected to the right and left brake pedals 15 and 16 and the right and left hydraulic cylinders 21 and 22, and is connected to the ends of the linkage rods 19 and 20. The pins 19 a and 20 a are inserted into the long holes 11 a of the interchangeable member 11, and the pins 19 a and 20 a at the ends of the linkage rods 19 and 20 are located at the left end of the elongated hole 11 a of the interchangeable member 11.

  As a result, as shown in FIG. 3, when the right and left brake pedals 15 and 16 are not operated, the right and left hydraulic cylinders 21 and 22 are contracted, and the right and left brakes 17 and 18 are contracted. Is operated to the braking side, the movement of the pin 19a of the linkage rod 19 to the right side of the paper along the elongated hole 11a of the interchangeable member 11 causes the right and left brake pedals 15 and 16 to be stepped on. Do not move in the direction.

  As shown in FIG. 3, when the right and left hydraulic cylinders 21 and 22 are not contracted, the right and left brake pedals 15 and 16 are stepped on, and the right and left brakes 17 and 18 are moved to the braking side. Even if operated, the pin 20a of the linkage rod 20 only moves rightward in the drawing along the long hole 11a of the interchangeable member 11 by this operation, and the right and left hydraulic cylinders 21 and 22 do not operate to contract (right And the left hydraulic cylinders 21 and 22 do not resist the stepping operation of the right and left brake pedals 15 and 16).

  As described in FIG. 3 and the preceding item [1], the pitman arm 10 is swung within the straight position A0, and within the range of the right and left set angles A1 from the straight position A0, and the front wheel transmission 8 is operated to the standard state. In this state, the right and left hydraulic cylinders 21 and 22 are extended by the control device 8 and the control valves 23 and 24, and the right and left brakes 17 and 18 are operated to the brake release side.

  When the pitman arm 10 is swung beyond the right set angle A1 (corresponding to a turning operation to the right of the aircraft) as described in FIG. 3 and the previous item [1], the control device 8 and the control valve 6 As a result, the front wheel transmission 8 is operated to increase the speed, and the right and left front wheels 1 are driven at a higher speed than the right and left rear wheels 2, and the control device 8 and the control valve 23 The hydraulic cylinder 21 is contracted and the right brake 17 is operated to the braking side to perform a small turn to the right (corresponding to an automatic turning means).

  As described in FIG. 3 and the preceding item [1], when the pitman arm 10 is swung beyond the left set angle A1 (corresponding to the turning operation of the aircraft to the left), the control device 8 and the control valve 6 As a result, the front wheel transmission 8 is operated to increase the speed, and the right and left front wheels 1 are driven at a higher speed than the right and left rear wheels 2, and the control device 8 and the control valve 24 The hydraulic cylinder 22 is contracted, the left brake 18 is operated to the braking side, and a small turn to the left is performed (corresponding to automatic turning means).

[4]
Next, a state in which the right and left brake pedals 15 and 16 are stepped on when stopping straight will be described with reference to FIG.
As shown in FIG. 3, a right pedal operation sensor 25 that detects that the right brake pedal 15 has been depressed is provided, and a left pedal operation sensor that detects that the left brake pedal 16 has been depressed. 25, and operation signals of the right and left stepping operation sensors 25 are input to the control device 8.

  When the right and left brake pedals 15 and 16 are stepped on and the operation signals of the right and left stepping operation sensors 25 are input to the control device 8 (step S1), the control devices 8 and The right and left hydraulic cylinders 21 and 22 are contracted by the control valves 23 and 24, and the right and left brakes 17 and 18 are operated to the braking side (step S2) (corresponding to auxiliary braking means). As a result, the stepping operation force of the right and left brake pedals 15 and 16 and the operation force of the right and left hydraulic cylinders 21 and 22 are transmitted to the right and left brakes 17 and 18, and the right and left brake pedals 17 and 18 are operated. The brakes 17 and 18 are fully operated to the braking side.

  Even if the driver's feet are released from the right and left brake pedals 15 and 16 and the right and left brake pedals 15 and 16 are returned (step S3) after the airframe has stopped, the control device 8 and the control valve 23, 24, the right and left hydraulic cylinders 21, 22 are maintained in a contracted state, and the right and left brakes 17, 18 are maintained on the braking side (step S4) (corresponding to auxiliary braking means). . Thereby, for example, even when the right and left brake pedals 15 and 16 are returned when the aircraft is stopped on a slope or the like, the right and left hydraulic cylinders 21 and 22 are maintained in a contracted state, and the right and left Since the left brakes 17 and 18 are maintained on the braking side, the aircraft does not move along the slope.

  After the aircraft has stopped, the driver's feet have been released from the right and left brake pedals 15 and 16, and the right and left brake pedals 15 and 16 have been operated to return, for example, when the vehicle is started (for example, (When the clutch pedal 14 is depressed to operate the main clutch in the disengaged state, the main and sub-transmission devices are shifted, the clutch pedal 14 is returned and the main clutch is operated to the transmission state)) In step S5), the set time T1 is counted by the timer (step S6).

  Since the engine power is actually transmitted to the right and left front wheels 1 and the right and left rear wheels 2 during the elapse of the set time T1, when the set time T1 elapses (step S7), control is performed. The right and left hydraulic cylinders 21 and 22 are extended by the device 8 and the control valves 23 and 24, and the right and left brakes 17 and 18 are operated to the brake release side (step S8) (to the auxiliary braking means). Equivalent). Thereby, the aircraft can be started without retreating the aircraft along the slope.

[First Alternative Embodiment of the Invention]
In the above-mentioned [Best Mode for Carrying Out the Invention], it may be configured as shown in FIGS.
A main clutch (not shown) and a gear transmission type main transmission (not shown) are eliminated, and a hydrostatic continuously variable transmission (not shown) is provided instead. The hydrostatic continuously variable transmission is configured to be steplessly variable from a neutral position and a neutral position to a forward high speed side and a reverse high speed side.

  As shown in FIG. 5, a rotary tiller 26 is supported at the rear of the machine body so as to be movable up and down, and engine power is transmitted to the rotary tiller 26 via a PTO clutch (not shown) and a PTO shaft 27. The tilling claw 26a of the rotary tiller 26 is rotationally driven in the clockwise direction of the paper (see arrow B1) in FIG. The tillage device 26 pushes the machine forward (to the right in FIG. 5), and the power of the engine is transmitted to the right and left front wheels 1 and the right and left rear wheels 2 so that the machine runs, so that the rotary tillage is performed. The device 26 receives the force that pushes the aircraft forward by the aircraft.

Next, a state where the right and left brake pedals 15 and 16 are stepped on when stopping straight will be described with reference to FIG.
When the right and left brake pedals 15 and 16 are stepped on and the operation signals of the right and left stepping operation sensors 25 are input to the control device 8 (step S11), the control device 8 is stopped. The right and left hydraulic cylinders 21 and 22 are contracted by the control valves 23 and 24, and the right and left brakes 17 and 18 are operated to the braking side (step S12) (corresponding to auxiliary braking means). The hydraulic continuously variable transmission is automatically operated to a neutral position by an operating cylinder (not shown) (step S13).

As a result, the stepping operation force of the right and left brake pedals 15 and 16 and the operation force of the right and left hydraulic cylinders 21 and 22 are transmitted to the right and left brakes 17 and 18, and the right and left brake pedals 17 and 18 are operated. The brakes 17 and 18 are fully operated to the braking side.
In this case, when the PTO clutch is operated in the transmission state (when the tilling claw 26a of the rotary tiller 26 is driven to rotate), the PTO clutch is automatically operated in the disengaged state (of the rotary tiller 26). The tilling claw 26a is stopped) (step S14).

  After the aircraft has stopped, the right and left brake pedals 15 and 16 are operated to return, and the vehicle starts to operate (for example, the hydrostatic continuously variable transmission is operated from the neutral position to the high speed side of advance) When the right and left brake pedals 15 and 16 are returned (step S15), the PTO clutch is automatically operated in the transmission state (because the tilling claw 26a of the rotary tiller 26 is rotationally driven). (Although step S16), the control device 8 and the control valves 23 and 24 cause the right and left hydraulic cylinders 21 and 22 to contract and the right and left brakes 17 and 18 are operated to the braking side. The count of the set time T2 by the timer is started (step S17).

  During the elapse of the set time T2, the start operation of the fuselage (for example, operation of the hydrostatic continuously variable transmission from the neutral position to the forward high speed side) is performed, and the engine power is actually increased to the right and left front wheels 1, Since it is transmitted to the right and left rear wheels 2, when the set time T2 elapses (step S18), the right and left hydraulic cylinders 21, 22 are extended by the control device 8 and the control valves 23, 24. Then, the right and left brakes 17 and 18 are operated to the brake release side (step S19).

  When the aforementioned PTO clutch is automatically operated in the transmission state (when the tilling claw 26a of the rotary tiller 26 is driven to rotate) (step S16), the right and left brakes 17 and 18 are operated to the brake release side. When the hydrostatic continuously variable transmission is operated to the neutral position, it is conceivable that the airframe advances due to the force that the rotary tiller 26 pushes the airframe forward. In this case, since the right and left brakes 17 and 18 are still operated to the braking side, the aircraft does not move forward by the force of the rotary tiller 26 pushing the aircraft forward.

[Second Embodiment of the Invention]
In the above-mentioned [Best Mode for Carrying Out the Invention] [First Alternative Embodiment], a wire (not shown) (corresponding to a linkage mechanism) may be used instead of the linkage rod 19. . Instead of the right and left hydraulic cylinders 21 and 22, electric cylinders (corresponding to actuators) may be used.
Instead of the right and left front wheels 1 and the right and left rear wheels 2, right and left crawler traveling devices (not shown) (corresponding to traveling devices) are provided, and the right and left crawler traveling devices are provided with right and left The present invention can also be applied to work vehicles equipped with the brakes 17 and 18.

2 right and left traveling devices 15 right brake pedal 16 left brake pedal 19 linkage mechanism 21 right actuator 22 left actuator T1 set time

Claims (2)

Artificially operated right and left brake pedals;
Right and left brakes for right and left travel devices;
A right linkage mechanism for operating the right brake to the braking side when the right brake pedal is depressed;
A left linkage mechanism for operating the left brake to the braking side when the left brake pedal is depressed;
A right actuator provided separately from the right brake pedal and the right linkage mechanism and capable of operating the right brake to a braking side;
The left brake pedal and the left linkage mechanism are provided separately, and the left actuator that can operate the left brake to the braking side and the power transmission to the PTO shaft that transmits engine power to an external device Or a PTO clutch that switches between shut-off and
An auxiliary braking means for operating the right and left actuators on the braking side of the right and left brakes when the right and left brake pedals are depressed,
When the right and left brake pedals are stepped on and the right and left actuators are actuated to the braking side of the right and left brakes, if the PTO clutch is in a transmission state, it is operated in a disconnected state,
Thereafter, when the right and left brake pedals are returned, the right and left actuators are maintained on the braking side of the right and left brakes, and the PTO clutch operated in the disconnected state is operated in the transmission state. Working vehicle.   The auxiliary braking means is configured to actuate the right and left actuators from the braking side of the right and left brakes to the braking release side after a set time has elapsed since the start of the aircraft starting operation. The work vehicle according to claim 1, comprising:

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