JP3164905B2 - Tractor swing brake - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of automatically applying a brake to a rear wheel on the turning center side during turning of a tractor.
The present invention relates to a technique for obtaining a sharp turn with a small radius.

[0002]

2. Description of the Related Art During tilling work with a tractor,
The turning radius of the tractor is made as small as possible in order to til the adjacent strips efficiently. Conventionally, in order to obtain such a small radius turn, separately operated brakes are provided on each of the left and right rear wheels, and brake pedals are also provided one by one for each brake. When the brake pedal is depressed, the wheel is turned with the brake applied, and the vehicle is turned sharply so as not to damage the field, there is a method of providing a front wheel speed increasing device.

[0003]

In the above prior art, first, the method of depressing the brake pedal on one side increases the number of parts constituting the brake pedal, increases the cost of the tractor, and increases the cost. Since they are arranged in a line, it is easy to make a mistake in depressing the brake pedal. If the driver makes a mistake, the brake is applied to the rear wheel on the outer peripheral side of the turn, and the tractor may roll over during the turn. Also, when the front wheel speed increasing device is operated, a wrong brake pedal is similarly dangerous.

[0004]

The present invention uses the following method to solve the above problems. In the braking device of the tractor T, the left and right rear wheels
The brakes 4L and 4R are provided on 2L and 2R,
L ・ 4R can be braked by actuators 5L ・ 5R
Then, the actuators 5L and 5R are connected to the steering wheel.
When the turning angle of the tool 3 has turned by more than the set value, the turning direction
While braking, position the center of gravity of the vehicle
Detects inclination and detects whether the vehicle body is rising forward or the center of gravity is
The brakes 4L and 4R are less effective
Is what you do.

[0005]

The operation of the present invention configured as described above will be described. At the time of farm work on a field, if the steering wheel is rotated by turning to the adjacent streak or the like, when the angle exceeds a certain angle, the steering shaft is twisted and the steering sensor is turned on, and the brake on the turning center side is turned. The hydraulic valve of the actuator is switched, and the brake actuator is driven to operate the rear wheel brake on the same side. As a result, the rear wheel on the turning center side is braked, and a sharp turn with a small radius is obtained. When the brake pedal is depressed, the brakes on both sides are activated.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; FIG. 1 is a layout diagram showing a state in which the tractor using the turning brake of the present invention is turning leftward,
2 is a side cross-sectional view showing the structure of the steering sensor 11, FIG. 3 is a plan cross-sectional view of the same, FIG. 4 is a plan cross-sectional view of a left-hand turn and one-side brake operation, and FIG. FIG. 5 is a layout diagram showing a state in which the vehicle is turning left in a tractor using a turning brake that performs automatic control of the vehicle.

Referring to FIG. 1, the structure of the turning brake according to the present invention will be described. On the tractor T, the front wheel 1L
1R is steered by the steering wheel 3, and the rear wheels 2L and 2R each have a brake 4
L · 4R is provided. Each of the brakes 4L and 4R is braked by operation of a brake actuator 5L and 5R that is driven by hydraulic pressure, and is provided with hydraulic valves 6L and 6R.
Activated by pressure oil from

When the steering wheel 3 is rotated by a certain angle or more, the hydraulic valves 6L and 6R are provided with a steering sensor 11L or 1L provided on the steering shaft 10.
By turning on 1R (or when the turning angle of the front wheels 1L and 1R is equal to or more than a certain value, the tire turning angle sensor 17L or 1R
When the 7R is turned on or when the rotation angle sensor rotates by a fixed angle, the hydraulic valve on the turning center side is switched, and the hydraulic oil from the pump P is sent to the brake actuators 5L and 5R, and the actuators are driven to perform braking. .

FIG. 1 shows a state where the vehicle body is turning leftward, the hydraulic valve 6L is switched, the brake actuator 5L is operated, and the brake 4L brakes the left rear wheel 2L. The position where the brake actuator is provided is not limited. Further, the brake actuator may be configured to be driven by an electric motor, and may be configured to include electric motors for driving the left and right actuators instead of the hydraulic valves. In this case, the steering sensor 11L or 11R (the tire turning angle sensor 17L or 17R)
By N, one of the left and right electric motors is driven and the actuator is driven.

In addition, one brake pedal 7 is provided at the step in the driver's seat. Conventionally, two left and right brake pedals are provided to apply a brake to the rear wheel on one side during a turn, but in the present invention, the one-side brake during a sharp turn is provided by an actuator for the brake. And only one brake pedal 7 is provided. When the brake pedal 7 is depressed, both hydraulic valves 6L and 6R are switched to operate both brake actuators 5L and 5R to apply a brake to both rear wheels 2L and 2R. In other words, the one-side brake during turning is automatically applied without the need to depress the brake pedal, and the brake pedal 7 is used for stopping the vehicle body in an emergency or the like. In this way, each
No need for two brake pedals for rear wheels
(One brake pedal is provided for stopping the vehicle),
It prevents accidental operation of the brake pedal and is safe.
This leads to a reduction in the cost.

The operation of the one-side brake during turning as described above is used during a sharp turn during work, and is dangerous when operating during a turn while traveling on a road. Therefore, during traveling on the road, the hydraulic valves 6L and 6R are not operated by steering the front wheels. For example, when the auxiliary transmission lever 8 is at a low speed, the hydraulic valves 6L and 6R are switched,
The hydraulic valves 6L and 6R are prevented from being switched at the time of high speed or reverse. In a tractor capable of driving the front wheels, it is also possible to add front wheel speed increase.

Next, the structure of the steering sensor 11 provided on the steering shaft 10 will be described with reference to FIGS. The steering mechanism of the tractor T uses power steering. For example, as shown in FIG. 1, the steering wheel 10 is turned left and right by the steering wheel 3 to switch the steering valve 13 to extend and retract the hydraulic cylinder 14. Thus, the front wheels 1L and 1R are turned by rotating the bell crank 16 connecting the tie rods 15L and 15R from the front wheels 1L and 1R to the left and right.

As shown in FIG. 2, the steering shaft 10 in such a power steering structure has a lower steering shaft 10b fitted into an upper steering shaft 10a, and a vertical spring 12 connects the upper and lower steering shafts 10a and 10b. The lower steering shaft 10b is provided with a steering sensor pusher 11c, and the upper steering shaft 10a is provided with a left steering sensor 11L and a right steering sensor 11R, which are normally provided as shown in FIG. 11
L · 11R is arranged so as not to be pressed against the steering sensor pressing element 11a.

The two steering shafts 10a and 10b rotate integrally in the state shown in FIG. 3 within the rotation range of the lower steering shaft 10b.
When the steering wheel 3 is turned further than the turning wheel b becomes full and the steering wheel 3 is turned further than that, for example, as shown in FIG. As a result, the steering sensor 11L is turned to the steering sensor pressing member 11a.
And the switch is turned on. As a result, FIG.
The brake valve 5L is switched to drive the brake actuator 5L of the rear wheel on the turning center side to apply the brake. When turning rightward, the lower steering shaft 10a of the upper steering shaft 10a is similarly turned.
b, the steering sensor 10R
Is pressed against the steering sensor pusher 11a and turned on to switch the hydraulic valve 6R, and the right rear wheel 2R
To operate the brake. When the rotation of the steering wheel 3 is loosened, the upper steering shaft 10
a returns to the original position by the restoring force of the spring 12, and the steering sensor 11 is turned off, so that the one-side (turn center side) brake is immediately released.

Such a configuration of the steering sensor 11 is effective in a power steering structure in which the upper and lower steering shafts 10a and 10b rotate within a predetermined range without twisting, but when the power steering does not work due to a failure or the like. In this case, the upper and lower steering shafts are twisted, and the steering sensors 11L and 11R are turned on despite the insufficient turning angle. In order to operate the one-side brake at a constant turning angle even in such a situation, it is effective to detect the turning angle of the tire. Therefore, the steering sensor 11L
The tire turning angle sensors 17L and 17R are disposed on both front wheels 1L and 1R as auxiliary switches for the 11R, respectively. When the front wheel 1L or 1R turns more than a certain amount, the tire turning angle sensor 17L on the turning center side. Or 17
R turns on and switches the hydraulic valve 6L or 6R.

FIG. 5 shows a vehicle body based on the running conditions such as the running speed of the tractor T at the time of turning and various field scene conditions (for example, inclination of the field) based on the structure of the turning brake shown in FIG. FIG. 2 illustrates a configuration for detecting a situation and adjusting the effectiveness of a turning brake. In other words, the steering angle sensor S
1. The running speed sensor S2, the front / rear center of gravity detection sensor (or front / rear inclination detection sensor) S3, the work implement detection sensor S4, the brake wheel rotation speed detection sensor S5, and the front wheel speed increase switch S6 are connected to the control unit 9 and The section 9 controls the switching of the hydraulic valves 6L and 6R to operate the brake actuators 5L and 5R.

The steering angle sensor S1 detects the steering angle, and the greater the angle, the sharper the turn, the greater the braking effect is required to assist the sharp turn. The traveling speed sensor S2 detects the number of revolutions of the axle (front wheel) other than the braking shaft, or detects the shift position of the transmission. For example, during high-speed work, the vehicle turns sharply while suppressing the braking effect. Prevent the fall when time. In addition, the center of gravity of the vehicle body moves when the work machine is mounted or when the field has an inclination. If the body is raised forward or the center of gravity is applied to the rear,
Reduce the effectiveness of the brake. Further, the brake wheel speed sensor S5 detects the speed of the rear wheel on which the brake is applied, and controls the braking force based on the detected value and other detected values. When the front wheel speed increasing device is used together, the front wheel speed increasing switch (clutch) may be used if the brake is strongly applied during the front wheel speed increasing.
When S6 is turned on, the braking effect is reduced.

In the switching control of the hydraulic valves 6L and 6R, the braking force is controlled by changing the pulses. That is, if the valve is continuously switched by increasing the pulse width, the braking time of the brake becomes longer, the effectiveness of the brake is increased, and the pulse width is reduced and the pulse width is intermittently increased (by increasing the pulse interval). When the valve is switched, the braking time of the brake is shortened, and the effectiveness of the brake is reduced, which is the same as applying the brake lightly.

[0019]

According to the present invention, the following effects can be obtained by the above configuration. That is, during the operation by the tractor, the turning on the turning side is applied at the time of a sharp turn, so that the turning with a smaller radius is obtained, and the traversing distance is shortened at the time of tilling the adjacent streak, so that the tilling work can be performed efficiently. In addition, various detected values related to the vehicle
By controlling the effectiveness of the turning brake based on
Adjust the turning speed and the turning radius will be the appropriate radius.
The layers are good, so we can turn the car safely.
is there.

[Brief description of the drawings]

FIG. 1 is a layout view showing a state where a tractor using a turning brake according to the present invention is turning leftward.

FIG. 2 is a perspective view showing a structure of a steering sensor 11;

FIG. 3 is a plan sectional view of the same.

FIG. 4 is a plan sectional view showing a case where a one-side brake is operated when the vehicle is turning leftward.

FIG. 5 is a layout diagram showing a state in which the vehicle is turning leftward in a tractor using a turning brake for performing automatic brake control by detecting a vehicle body condition.

[Explanation of symbols]

 T Tractor 1L ・ 1R Front wheel 2L ・ 2R Rear wheel 3 Steering wheel 4L ・ 4R Brake 5L ・ 5R Brake actuator 6L ・ 6R Hydraulic valve 7 Brake pedal 10 Steering shaft 10a Upper steering shaft 10b Lower steering shaft 11L ・ 11R Steering sensor 11a Steering Pusher for sensor 12 Spring

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B62D 11/08

Claims (1)

(57) [Claims] In a braking device for a tractor T, the left and right
Brakes 4L and 4R are provided on each of the rear wheels 2L and 2R.
Rake 4L ・ 4R is controlled by actuator 5L ・ 5R
And the actuators 5L and 5R are steerable.
Turns when the turning angle of the wheel 3 turns by more than the set value
Braking the direction side and the center of gravity of the vehicle
The front and rear inclination of the vehicle,
When the heart is working, the brakes 4L and 4R are effective
A turning brake for a tractor, characterized by reducing the size of the tractor.