JPH0655949U - Power steering interlocking brake device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a power steering interlocking braking device that enables an operator, who is unfamiliar with driving, to easily perform an appropriate turning operation when cultivating adjacently in a field. [Structure] From the steering control unit 2 to the left and right cylinder ports 7b and 7c of the steering cylinder 7.
Electromagnetic switching valves 16R, 16L and counter balance valves 20R, 20L interlocking with the switching operation of the sub-transmission lever 21 are provided in series in the respective oil passages 15R, 15L to the oil passages 15R, 15L. Counter balance valves 20R, 2 from outlet ports 16a, 16b
While reaching the 0L inlet port, the left and right braking mechanisms 17R,
Brake cylinders 18R and 18L connected to 17L are connected to each other, and the rear wheels of the steering inside are braked in cooperation with the start of steering of the front wheels 8R and 8L.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 When the power steering handle of an agricultural tractor or the like is started to be steered to the left or right, such as when cultivating adjacent fields in the field, one brake is automatically applied to the rear wheel inside the steering wheel, making it unsuitable for driving. The present invention relates to a power steering interlocking brake device that enables even a proper worker to easily perform an appropriate steering operation.

[0002]

[Prior art]

 Conventionally, when steering an agricultural tractor in the field to cultivate the adjacent land, etc., the operator has to carry out a two-step cumbersome steering operation of fully turning the handle and stepping on the brake pedal of the rear wheel inside the steering. For beginners, old people, and women who are unfamiliar with this, the timing of the brake operation at this time is difficult, and it often becomes a large steering, and advanced driving technology is required for proper steering operation. And required skill.

Therefore, the applicant of the present invention, when the handle is fully turned during the adjacent tillage work, automatically brakes only the rear wheel on the inside of the steering, thereby avoiding a large steering around the airframe. We proposed a power-steering interlocking braking system that can easily perform precise adjacent cultivation without requiring advanced driving skills and skill. However, although the above proposed power steering interlocking brake device can improve the operability by eliminating the troublesome steering operation of the second stage, it does not operate after the inside of the steering wheel when the handle is fully turned. Since the wheels are braked, if there is a long time from the start of turning the steering wheel to the time when the steering wheel is fully turned, there is a danger that the timing of the steering of the aircraft will be misaligned and the aircraft will still make a large turn. .

[0004]

[Problems to be solved by the present invention]

 In view of the above situation, the present invention was devised in a research and development process for improving workability during adjacent tillage, and its purpose is to require no advanced driving technology. The purpose of the present invention is to provide a power steering interlocking braking device that enables even beginners, old people, and women who are unfamiliar with adjacent tillage work to easily perform appropriate steering operations.

[0005]

[Means for Solving the Problems]

 In order to solve the problem, the technical means adopted by the present invention is that the discharge oil of the hydraulic pump is sent to the steering cylinder via the steering control unit that is interlocked with the steering wheel operation, and the steering of the front wheels corresponding to the steering wheel operation is mechanically performed. In the power steering performed in step 1, the oil passages from the steering control unit to the left and right cylinder ports of the steering cylinder are connected in series with an electromagnetic switching valve and a counter balance valve that are linked to the switching operation of the auxiliary shift lever. Between the outlet port of the solenoid operated directional control valve and the inlet port of the counterbalance valve, the brake cylinders connected to the left and right braking mechanisms are connected, respectively, and the rear wheels on the inside of the steering wheel are linked to the start of steering on the front wheels. It is characterized by being configured to brake.

[0006]

[Function of the device]

 Therefore, according to the present invention, when the steering wheel is operated while the machine is traveling, steering of the front wheels is started, and at the same time, the rear wheels on the inside of the turning direction are immediately braked, so that smooth and reliable turning is possible during adjacent tillage. In addition to being able to perform steering, it is possible to eliminate the troublesome two-step operation of depressing the brake pedal on the steering side while operating the steering wheel, making it easy for even beginners who are not familiar with driving, such as when adjacent cultivating with an agricultural tractor etc. It is possible to carry out an appropriate steering operation.

[0007]

【Example】

 The configuration of the present invention will be described in detail based on an embodiment shown in the drawings. 1 to 3, 1 is a steering wheel of a vehicle such as an agricultural tractor in which the device of the present invention is incorporated, 2 is a steering control unit that is interlocked with the operation of the steering wheel, 3 is driven by an engine 4, and hydraulic pressure is applied to the steering control unit 2. A hydraulic pump for output power steering, 5 is a filter, 6 is an oil tank that also serves as a transmission case, and 7 is a hydraulic oil that is controlled by the steering control unit 2 and has pistons 7a with rods on both sides incorporated inside. It is a steering cylinder that power-steers the right and left front wheels 8R and 8L.

The steering control unit 2 is a rotary type direction in which the switching direction of the oil passage is switched to the L, N and R positions in response to the inlet check valve 9, the relief valve 10, the internal check valve 11 and the steering wheel operation. A metering device 14 for feeding back pressure oil to the direction switching valve 12 via a mechanical link 13 is added to the steering valve 7 to adjust the amount of pressure oil sent to the steering cylinder 7. The left and right oil inlet / outlet passages 15R and 15L of the steering control unit 2 are connected to electromagnetic switching valves 16R and 16L, respectively.

At the outlet ports 16a and 16b of the electromagnetic switching valves 16L and 16R, inlet ports 18a and 18b of brake cylinders 18R and 18L corresponding to braking mechanisms 17R and 17L for the right and left rear wheels (not shown) are respectively provided. The cylinder rods 18 'and 18' are retracted by the pressure oil from the steering control unit 2 so that the braking mechanisms 17R and 17L are independently driven for braking. . Further, the outlet ports 19a and 19b of the brake cylinders 18L and 18R are connected to the steering cylinder 7 through left and right counterbalance valves 20L and 20R which operate at predetermined pressure oil pressures, respectively, and are partitioned by a piston 7a. Pressure oil from the steering control unit 2 that is pressure-fed through the brake cylinders 18R and 18L is supplied into the cylinder ports 7b and 7c.

On the other hand, the electromagnetic switching valves 16L and 16R are directly connected to the interlocking brake switch 22 via the switching switch 21a of the auxiliary transmission lever 21 arranged in the driver's seat of the vehicle, and the interlocking brake switch 22 is turned on. In this state, when the auxiliary transmission lever 21 is in the low / medium speed position, it is switched to the pressure oil inlet / outlet interlocking position A in FIG. 1, and when the auxiliary transmission lever 21 is switched to the high speed position, the changeover switch 21a is turned off, and As shown in 2, the pressure oil returns to the normal position B, and the pressure oil is directly supplied to the steering cylinder 7 through the right direct connection oil passage 15R 'and the left direct connection oil passage 15L' without passing through the brake cylinders 18R and 18L. Is configured to supply. Reference numeral 23 is an inlet oil passage of the steering control unit 2, 24 is an outlet oil passage of the steering control unit 2, and 25R and 25L are brake arms of the braking mechanisms 17R and 17L, respectively.

In the above configuration, when the handle 1 is stationary at the neutral position, the direction switching valve 12 is located at the neutral position N, and the output pressure oil of the hydraulic pump 3 is the inlet oil passage 23 of the steering control unit 2. The oil is turned on in the direction switching valve 12 to make a U-turn, and then exits from the outlet oil passage 24 and returns to the oil tank 6 repeatedly, and the oil passages from the direction switching valve 12 to the rest are in a stationary state. The metering device 14 is stationary, the piston 7a in the steering cylinder 7 is fixed at the neutral position, and the vehicle goes straight.

[0012] Here, the interlocking brake switch 22 is turned on to perform adjacent tillage and the like, and after the sub-shift lever 21 is switched to the low speed or medium speed position, the steering wheel 1 is turned clockwise, for example, to steer the front wheels. 1 is started, the direction switching valve 12 is switched to the R position shown in FIG. 1 in conjunction with the rotation of the handle 1, the pressure oil from the hydraulic pump 3 is supplied in the direction of the solid line arrow, and the right inlet / outlet passage 15R is supplied. To the electromagnetic switching valve 16R. Here, since the electromagnetic switching valve 16R is at the pressure oil inlet / outlet interlocking position A, the pressure oil is immediately sent from the outlet port 16b to the input port 18b of the brake cylinder 18R, and the cylinder rod 18 'of the brake cylinder 18R moves. As the vehicle is retracted and driven, the brake arm 25R is pulled in the braking direction, and the rotation of the right rear wheel is braked by the braking mechanism 17R simultaneously with the start of steering of the front wheels 8R, 8L.

Then, when the handle 1 is further rotated clockwise while the braking state of the right front wheel 8R is maintained, the cylinder rod 18 'is compressed to the compression limit, and is pumped from the right oil inlet / outlet passage 15R. When the pressure oil to be generated rises to a predetermined pressure, the right counterbalance valve 20R connected to the oil passage 15R is opened, and the pressure oil is supplied to the cylinder port 7c of the steering cylinder 7 to move the piston 7a. As the front wheels 8R and 8L move in and out in the direction of the solid line arrow, the front wheels 8R and 8L are steered to the right direction as shown by the solid line arrow in FIG. 3, and the vehicle turns to the right. Return to the solenoid switching valve 16L via the center balance valve 20L and the brake cylinder 18L, and from the direction switching valve 12 to the outlet oil passage via the left oil inlet / outlet passage 15L. It is returned to the oil tank 6 through 4.

Further, when the handle 1 is rotated counterclockwise, the direction switching valve 12 that interlocks with the handle 1 is switched to the L position contrary to the above, and the pressure oil of the hydraulic pump 3 is transferred to the electromagnetic switching valve 16L. Is supplied to the brake cylinder 18L via the counter balance valve 20L and is supplied to the cylinder port 7b of the steering cylinder 7 via the counterbalance valve 20L, and the piston 7a moves leftward to the front wheel 8R, 8L will be steered to the left as indicated by the broken line arrow at an angle proportional to the turning angle of the handle 1 as described above.

Therefore, when the steering operation of the front wheels 8R and 8L is started, the braking operation of the front inside wheels is immediately performed, and the steering wheel is turned to the steering side and the brake pedal on the steering side is depressed at the time of adjacent tillage. Since it is only necessary to turn the steering wheel without the need for two-step operation, even beginners unfamiliar with driving can easily and smoothly turn the machine for adjacent tillage work.

When the auxiliary shift lever 21 is switched to the high speed position, the changeover switch 21a is turned off regardless of whether the interlocking brake switch 22 is turned on or off. The pressure oil supplied from the steering control unit 2 after returning to the normal inlet / outlet position B is supplied to the cylinder ports 7b and 7c of the steering cylinder 7 via the right direct connection oil passage 15R 'and the left direct connection oil passage 15L'. Prevents accidents such as switching to normal power steering steering operation and not performing rear-wheel braking operation inside the steering wheel at high speed operation, suddenly applying one brake to the rear wheel and overturning the vehicle. be able to.

[0017]

[Effect of device]

 In essence, the present invention provides the above-mentioned power steering system in which the oil discharged from the hydraulic pump is sent to the steering cylinder via a steering control unit that is interlocked with the steering wheel operation to mechanically steer the front wheels corresponding to the steering wheel operation. In each oil passage from the tearing control unit to the left and right cylinder ports of the steering cylinder, an electromagnetic switching valve and a counter balance valve that interlock with the switching operation of the auxiliary transmission lever are installed in series, and the outlet of the electromagnetic switching valve is connected. The brake cylinders connected to the left and right braking mechanisms were connected between the port and the inlet port of the counterbalance valve, and the rear wheels inside the steering were braked in coordination with the start of steering of the front wheels. , As in the past, when turning adjacent steering, turn the steering wheel to the steering side and operate it. The front wheel steering starts immediately when the steering wheel is operated while the aircraft is running, and the rear wheels on the inside of the turning direction are immediately braked without the need for advanced driving technology such as stepping on the brake pedal of the adjacent cultivator. Even beginners, old people, and women who are unfamiliar with the work can easily perform accurate steering operations, prevent large-scale turning of the aircraft in advance, and perform efficient adjacent tillage work. The braking power of the brake cylinder can be easily set by adjusting the opening pressure of the counterbalance valve, and the braking force of the braking mechanism can be adjusted easily and reliably. It is effective.

[Brief description of drawings]

FIG. 1 is an overall hydraulic circuit diagram of a power steering interlocking brake device.

FIG. 2 is a diagram for explaining the operation of the solenoid directional control valve.

FIG. 3 is an operation explanatory view showing a steering state of front wheels.

[Explanation of symbols]

 1 Steering Wheel 2 Steering Control Unit 3 Hydraulic Pump 7 Steering Cylinder 8R Right Front Wheel 8L Left Front Wheel 7b Cylinder Port 7c Left and Right Cylinder Ports 15R Right Inlet / Outlet Passage 15L Left Outlet / Inlet Passage 16R Electromagnetic Changeover Valve 16L Electromagnetic Changeover Valve 16a Outlet Port 16b Outlet Port 17R Braking mechanism 17L Braking mechanism 18R Brake cylinder 18L Brake cylinder 20R Counterbalance valve 20L Counterbalance valve 21 Sub-shift lever

Claims (1)

[Scope of utility model registration request] 1. A power steering system in which oil discharged from a hydraulic pump is sent to a steering cylinder via a steering control unit that is interlocked with steering wheel operation to mechanically steer front wheels in response to steering wheel operation. In each oil passage leading to the left and right cylinder ports of the steering cylinder, an electromagnetic switching valve and a counter balance valve, which are interlocked with the switching operation of the auxiliary transmission lever, are installed in series, and from the outlet port of the electromagnetic switching valve to the counter balance valve. Brake cylinders connected to the left and right braking mechanisms are connected between the inlet port and the power steering interlock, which is configured to brake the rear wheels inside the steering in coordination with the start of steering of the front wheels. Brake device.