JPH10100920A - Steering control device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] The turning angle of a steered wheel has the same turning angle with respect to the operation amount of a steering wheel irrespective of the traveling speed of an airframe. SOLUTION: Switching between left and right brake pedals 6, 6 and left and right brake actuators for braking the left and right axles through left and right oil paths, respectively, and the left and right oil paths are separately fed in the middle of the left and right oil paths. An electromagnetic valve V1 having a position and a switching position communicating the left and right oil passages is provided, and a first metering motor 3 is connected to a steering valve V2 constituting a power steering, and the operation of the steering wheel 3 is fed back to the second valve. A second metering motor 31 is connected in parallel to one metering motor via an electromagnetic valve V3, the electromagnetic valve V1, the electromagnetic valve V3, and a selection switch 5 for switching between a high-speed traveling mode and a low-speed traveling mode.
0 was connected to the controller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for changing the turning angle of a steered wheel with respect to the operation amount of a steering wheel in accordance with the traveling speed of an airframe.

[0002]

2. Description of the Related Art Conventionally, right and left steered wheels of a rice transplanter, a tractor, and the like are rotatably supported by a rotatable case having wheels supported on left and right ends of a front axle case horizontally provided on the body. A knuckle arm is fixed to the case, a tie rod is pivotally supported at the rear end of the knuckle arm, the tie rod is connected to a hydraulic cylinder, and the hydraulic cylinder is extended and retracted to match the turning angle of the steering wheel. The technology of a steering device that turns the fuselage by changing the cutting angle is known.

[0003]

The steering apparatus described above is
The steering angle of the steering wheel is changed according to the steering angle of the steering wheel. The turning angle of the steered wheels is constant with respect to the turning angle of the steering wheel, and switches to an angle that is proportional to the running speed regardless of the running speed.In addition, agricultural workers such as rice transplanters and tractors turn the front wheel so that turning is effective. Due to the large angle, the aircraft sometimes turns suddenly during high-speed running if the steering wheel is turned large as in work.

[0004]

SUMMARY OF THE INVENTION In order to solve such a problem, the present invention provides communication between left and right brake pedals and left and right brake actuators for braking left and right axles via left and right oil passages, respectively. In the middle of the left and right oil passages, there is provided a solenoid valve V1 having a switching position for separately feeding the left and right oil passages and a switching position for communicating the left and right oil passages, and a first metering for a steering valve V2 constituting a power steering. The motor is connected and the operation of the handle is fed back, and the electromagnetic valve V is connected to the first metering motor.
3, a second metering motor is connected in parallel, the electromagnetic valve V1, the electromagnetic valve V3, and a selection switch for switching between a high-speed traveling mode and a low-speed traveling mode are connected to a controller.・
By switching V3, the left and right brake actuators can be operated separately, and the first and second metering motors are operated during turning.

Alternatively, the left and right brake pedals and the left and right brake actuators for braking the left and right axles communicate with each other through left and right oil passages. An electromagnetic valve V1 having a switching position communicating the left and right oil passages, and connecting a variable metering motor to a steering valve V2 constituting a power steering, feeding back the operation of a steering wheel, and tilting the variable metering motor. The plate can be changed by an actuator, and the electromagnetic valve V1, the actuator, and a selection switch for switching between a high-speed traveling mode and a low-speed traveling mode are connected to a controller. Actuator can be operated, and when turning, the actuator The drives are those configured to increase the flow rate of the variable metering motor.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The problems to be solved by the present invention and means for solving them are as described above. Next, the configuration of the embodiment shown in the attached drawings will be described. 1 is an overall plan view of a tractor, FIG. 2 is a circuit diagram showing a brake configuration for braking both axles, FIG. 3 is a circuit diagram for controlling a turning angle of a front wheel of the present invention, and FIG. 4 is controlling a turning angle of a front wheel. FIG. 9 is a circuit diagram showing another embodiment.

Referring to FIG. 1, a tractor A of this embodiment will be described. On the upper part of the frame F, a bonnet 1 for mounting the engine E is mounted in the front, and a dashboard 2 is erected at the rear end thereof to protrude a steering handle 3. Step part 4 behind
Are formed using the upper surface of the frame F. A brake pedal 6.6 projects upward from the frame F at the right front part, and a clutch pedal 12 projects at the left side. A seat 5 is arranged behind the step portion 4, and a sub-shift lever 7 for switching between low-speed running and high-speed running, a lifting / lowering lever 8 of a working machine, and a working depth setting lever 9 are protruded from the side of the seat 5. And the lower link 55 on the left and right from the rear of the fuselage
The work implement B is mounted so as to be able to move up and down by protruding the top link 56 at the center position with 55.

The front wheels 10 are steered by the steering wheel 3. Power is transmitted to the transmission case M from an output shaft protruding from the engine E, and drives rear wheels 11 serving as driving wheels via axles 45 protruding left and right from the rear of the transmission case M. .

Next, the transmission is shifted by a transmission in the transmission case M, and after the shift, the rear wheels 11 are connected via a differential mechanism.
With reference to FIG. 2, a transmission structure for transmitting power to the vehicle and enabling braking will be described. The power shifted by the transmission case M is transmitted to the differential ring gear 41 of the differential mechanism D via a drive gear. A differential case 39 is fixedly mounted on a side surface of the differential ring gear 41, and differential pinions 42 and 42 that rotate integrally with the differential case 39 and the differential ring gear 41 are loosely fitted inside the differential case 39. On the other hand, the differential side gears 43, 44 are fixed to the inner ends of the left and right axles 45, 45, and the differential side gears 43, 44 are meshed with the differential pinion gears 42, 42. Is transmitted to the axles 45. Further, power is transmitted to the rear ends of the axles 45 via the reduction gears 47 for the left and right rear wheels 11.

FIG. 2 shows the side of the axles 45 and 45.
As shown in the figure, brake mechanisms (braking devices) 49 are provided. The brake mechanisms 49, 49 are operated in conjunction with the operation of the brake pedals 6, 6. That is,
The brake pedals 6 are fixedly mounted on a rotating shaft 14, and a piston rod of a cylinder 16 is connected to an arm 15 protruding from the rotating shaft 14. Left and right cylinders 1
6 and 16 are connected to oil passages 17R and 17L.
R.17L is connected to the primary side of the switching valve V1.
The secondary side of the valve V1 is connected to cylinders of brake mechanisms 49, 49 via oil passages 18R, 18L.
The valve V1 is a four-port, two-position switching type solenoid valve. The solenoid 19 is excited to switch between a high-speed running state in which the left and right oil paths are communicated and a low-speed running state in which the left and right oil paths can be operated independently. It is possible to switch.

In other words, in a low-speed running state, when the oil passages 17R and 18R are connected to each other and the oil passages 17L and 18L are connected to each other and one of the brake pedals 6 is depressed, the brake on that side is depressed. The mechanism 49 is actuated to provide a one-sided brake and a sharp turn. In the high-speed running state (high-speed mode), all the oil passages 17R, 17L, 1
8R and 18L are connected and communicated so that the brake mechanisms 49 on both sides operate even when the brake pedal 6 on one side is depressed. The solenoid 19 of the electromagnetic valve V1 is connected to a controller C, and a selection switch 50 is connected to the controller C. By operating the selection switch 50, the electromagnetic valve V1 can be switched. However, it is also possible to connect the vehicle speed sensor to the controller C and always switch the electromagnetic valve V1 to attain a high-speed running state at a speed higher than the set speed. Further, the selection switch 50 may be arranged in the auxiliary transmission.

Next, the turning angle operation mechanism of the front wheels 10, 10, which are the left and right steering wheels, will be described. As shown in FIG. 3, a turning case in which knuckle arms 22 are fixedly mounted on both left and right ends of a front axle case 21 is pivotally supported, and the front wheels 10 are rotatably supported by the turning case. I have. The ends of the rods 24 of the double rod type power steering cylinder 23 are connected to the rear portions of the left and right knuckle arms 22. And the power steering cylinder 23
By sending pressure oil to one of the left and right oil chambers 23R and 23L and operating the power steering cylinder 23, the front wheel 1
The cut angle of 0.10 is changed.

The pressure oil from the hydraulic pump P is sent to the steering valve V2. The steering valve V2 is a 6-port 3-position switching type valve, and its spool is connected to the output shaft 52 of the metering motors 30 and 31 and the handle shaft of the steering handle 3 in an interlocked manner. An oil passage 26 connected to the hydraulic pump P and a drain oil passage 27 serving as a return circuit for the pressure oil are connected to the primary side of the steering valve V2. An oil passage 28 for supplying pressure oil to the power steering cylinder 23 and an oil passage 2 are provided on the secondary side of the steering valve V2.
9 and the metering motor 30
The oil passages 31 and 33 are connected to oil passages 32 and 33.

The first metering motor 30 and the second metering motor 31 are connected in parallel via a solenoid valve V3, and the oil passage 3 is connected to the primary side of the solenoid valve V3.
2 and 32 to the first metering motor 30 and the steering valve V2.
The second metering motor 31 is connected to the secondary side of the pump 2 via oil passages 35 and 36. The solenoid valve V3 is a four-port two-position switching type solenoid valve, and its solenoid 37 is connected to the controller C.
Is switched to a speed-up state in communication with the block state by a signal from the controller. Further, the controller C
Is connected to a selection switch 50. The selection switch 50 switches between a low-speed traveling mode and a high-speed traveling mode. The steering valve V2 is connected so that the operation can be switched by the handle 3.

In such a configuration, the selection switch 5
When 0 is switched to the high-speed traveling mode, the electromagnetic valve V3 is switched to the block state. In this state, when the steering wheel 3 is turned to perform a turning operation, for example, a left turning operation, the steering valve V2 is switched, the oil passage 26 and the oil passage 32 are connected, and the pressure oil generated by the hydraulic pump P is supplied to the oil passage 32. We are refueling. The pressure oil in the oil passage 32 is supplied to the oil passage 33 by driving the first metering motor 32, and is sent into the oil chamber 23 </ b> L of the power steering cylinder 23 via the oil passage 29. At this time, the first metering motor 32 drives the output shaft 52, drives the steering valve V2 to switch to the neutral position, and comes to the neutral position at a position corresponding to the steering angle of the steering wheel 3.

In this high-speed running mode, the electromagnetic valve V1 for operating the brake mechanisms 49, 49 of the rear wheels 11, 11 is in a high-speed running state, and the left and right brake pedals 6, 6 are depressed. However, since the brake devices 49 on both sides are actuated, there is no one-side brake, and the aircraft does not turn sharply. The same operation is performed when turning right.

When the selection switch 50 is switched to the low-speed traveling mode, the electromagnetic valve V3 is switched, so that the oil passage 32 and the oil passage 35 communicate with each other, and the oil passage 33 and the oil passage 36 communicate with each other. In this state, when the operation handle 3 is operated to make a left turn, for example, the steering valve V2
Is switched, and the pressure oil from the hydraulic pump P is sent to the oil passage 32. The pressure oil sent to the oil passage 32 drives the first metering motor 32, and further drives the second metering motor 31 from the oil passage 35 via the electromagnetic valve V3, so that the oil passage 36 The oil is fed from the path 33 to the power steering cylinder 23. Therefore, the pressure oil from the first metering motor 30 and the second metering motor 31 is supplied to the oil chamber 23L via the oil passage 29, and the power steering cylinder 23
Is greatly moved, and the turning angle of the front wheels 10, 10 can be increased to make a sharp turn. In this low-speed traveling mode, the electromagnetic valve V1 is switched to the low-speed traveling state. When the left brake pedal 6 is depressed, the brake 49 is activated and the front wheels 10 are operated.
The sharp turning of the aircraft can be performed by the large turning angle of 10 and the braking of the left rear wheel 11. When the electric system of the electromagnetic valves V1 and V3 fails, that is, in a state where power is not supplied, the spool is switched to the high-speed mode by a spring, and the steering operation can be performed safely without sudden turning.

Further, as described above, it is also possible to adopt a configuration in which the oil supply amount is adjusted by one variable displacement type motor 62 without using two metering motors 30 and 31. That is, as shown in FIG. 4, a variable displacement motor 62 is disposed between the oil passage 32 and the oil passage 33, and the angle of the movable swash plate of the motor 62 is adjusted by rotating the actuator 63 such as a solenoid. Change by the action,
By connecting the actuator 63 to the controller C,
A selection switch 50 is connected to the controller C. When the selection switch 50 is set to the low-speed traveling mode, the actuator 63 is driven so as to increase the discharge amount of the variable displacement motor 62. 63
And the same operation and effect as described above can be obtained.

[0019]

According to the above configuration, in the high-speed mode, even if one of the left and right brake pedals is depressed, the brake actuators on both sides are operated and both wheels are braked.
There is no one-sided brake, and there is no turning with the brake operation. When the low-speed mode is set, depressing one of the left and right brake pedals causes a one-sided brake, enabling a sharp turn.
The front wheels can be largely cut with a small angle of cut, so that the operation of turning the aircraft rapidly can be facilitated, and the operability can be improved.

[Brief description of the drawings]

FIG. 1 is an overall plan view of a tractor.

FIG. 2 is a circuit diagram showing a brake configuration for braking both axles.

FIG. 3 is a circuit diagram for controlling a turning angle of a front wheel according to the present invention.

FIG. 4 is a circuit diagram showing another embodiment for controlling a turning angle of a front wheel.

[Explanation of symbols]

 P pump V1 Solenoid valve V2 Steering valve V3 Solenoid valve 21 Front axle case 23 Power steering cylinder 30 First metering motor 31 Second metering motor

Claims (2)

[Claims] The left and right brake pedals and left and right brake actuators for braking the left and right axles communicate with left and right oil passages respectively, and a switching position for separately feeding left and right oils in the middle of the left and right oil passages. An electromagnetic valve V1 having a switching position communicating the left and right oil passages, a first metering motor connected to a steering valve V2 constituting a power steering, and feedback of an operation of a steering wheel, to provide the first metering motor. A second metering motor is connected in parallel to the controller via an electromagnetic valve V3, and the electromagnetic valve V1, the electromagnetic valve V3, and a selection switch for switching between a high-speed traveling mode and a low-speed traveling mode are connected to a controller. By switching the solenoid valves V1 and V3, the left and right brake actuators can be operated separately, A steering control device configured to operate the first and second metering motors. 2. A left and right brake passage for communicating left and right oil passages between left and right brake pedals and left and right brake actuators for braking left and right axles, respectively. An electromagnetic valve V1 having a switching position communicating the left and right oil passages, and connecting a variable metering motor to a steering valve V2 constituting a power steering, feeding back the operation of a steering wheel, and tilting the variable metering motor. The plate can be changed by an actuator, and the electromagnetic valve V1, the actuator, and a selection switch for switching between a high-speed traveling mode and a low-speed traveling mode are connected to a controller. Actuator is operable and drives when turning A steering control device configured to increase the flow rate of the variable metering motor.