JPH07149253A - Control device for steering device in trailer - Google Patents

Abstract

PURPOSE:To provide a control device for a steering device by which nonconformity such as a temperature rise in a motor, an oil temperature rise and large electric power consumption can be eliminated by generating oil pressure by maximum output at steering time of a trailer, and normally generating low oil pressure. CONSTITUTION:In a steering device for a trailer to transmit the displacement to left and right rear wheels by a link mechanism through a steering panel of a wheel shaft by converting rotational displacement of a tractor into extensional and contractional displacement of a hydraulic cylinder 18 through oil pressure piping, the device has a control valve 40 having a characteristic to generate differential pressure in output by controlling the displacement of the cylinder at steering time of a trailer. Two relief valves 54 and 58 are connected in parallel to each other in oil pressure piping to connect the control valve and a hydraulic pump 48 to each other, and a solenoid valve 60 is connected in series to the relief valve whose designated pressure is low, and an electronic control device is provided to send a signal to an electric motor 46 and the solenoid valve according to differential pressure by detecting the differential pressure at output time of the control valve, and is constituted so that oil pressure is generated by maximum output at steering time of the trailer and low oil pressure is normally generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a steering device in a trailer, and more particularly to a control device for a steering device in which an electronic control device is incorporated in a hydraulic device for operating the steering device of the trailer. It is a thing.

[0002]

2. Description of the Related Art Generally, a trailer having a plurality of axles at its rear portion for transporting a heavy load has a plurality of axles at the rear portion of the trailer displaced in accordance with the rotational displacement of the tractor, thereby smoothing the movement. Although the steering device is provided so as to rotate, the structure of a plurality of axles at the rear of the trailer is shown in, for example, Japanese Patent Application No. 5-204741 filed by the applicant of the present invention. Pivotally rotatably pivot the wheels, pivotally pivot the steering wheel at the center of the axle, and rotatably connect the rotary arm and steering wheel with a connecting rod to form a link mechanism. The rotation displacement of the tractor is transmitted to the steering wheel at the center of the axle through hydraulic piping, and the displacement of the steering wheel is transmitted to the left and right rear wheels by the link mechanism, thereby displacing the left and right rear wheels. Was there.

[0003]

Normally, the steering device of the trailer is operated during turning, but at other times, the motor for generating hydraulic pressure for operating the steering device is always at the maximum output. Since it is rotating, the motor temperature rise (short life), oil temperature rise (oil cooler required), and large power consumption (battery rises, dynamo life shortens), etc. There was a problem.

An object of the present invention is to provide a steering device for a trailer which eliminates the above-mentioned problems by being configured to generate a hydraulic pressure with a maximum output when steering the trailer and normally generate a hydraulic pressure lower than that during steering. It is to provide a control device of.

[0005]

In order to achieve the above object, a rotator is rotatably connected to a tractor about a kingpin as a shaft, and a rear arm of a trailer which is towed and travels is provided with rotary arms on both sides. Pivotally rotatably pivot the wheels, pivotally pivot the steering wheel in the center of the axle, and rotatably connect the rotary arm and steering wheel with a connecting rod to form a link mechanism. The rotary displacement of the tractor is converted into the expansion / contraction displacement of the hydraulic cylinder through the hydraulic pipe, and the expansion / contraction displacement of the hydraulic cylinder is transmitted to the steering wheel at the center of the axle. Is transmitted to the left and right rear wheels by means of which the left and right rear wheels are displaced, and in the case of steering of the trailer, the cylinder-
Of the control valve having the characteristic of controlling the expansion and contraction displacement of the control valve and generating a differential pressure in the output and the hydraulic pipe connecting the control valve and the hydraulic pump rotating by the operation of the electric motor. A relief valve is connected in parallel, a solenoid valve is connected in series to a relief valve having a lower designated pressure, a differential pressure at the time of output of the control valve is detected, and based on this data, By providing an electric motor and an electronic control unit for sending an electric signal to the solenoid valve, the hydraulic pressure is generated at maximum output when steering the trailer, and normally lower than when steering. And a controller for a steering device in a trailer.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a state in which a rear wheel of a trailer according to the present embodiment is rotating in accordance with rotation of a tractor, and FIG. 1 shows a hydraulic piping diagram with an electronic control device according to the invention.

As shown in FIG. 1, a trailer 10 equipped with a steering device is rotatably connected via a king pin 14 which rotates with the rotation of the tractor 12, and the rotational displacement of the tractor 12 is changed. Hydraulic piping 16 (Japanese Patent Application No. 5-47)
Cylinder-18 through a structure as shown in 531)
Is transmitted to the rear steering wheel 20 to rotate the rear steering wheel 20, while the structure of the rear axles 22 and 22 of the trailer 10 is shown in FIG. Wheels 26, 26 are rotatably pivoted to the left and right via 24, and a rear steering wheel 20 is rotatably pivotally attached to the center of the axle 22 to connect the rotary arm 24 and the steering wheel 20. Since the link mechanism is configured by rotatably connecting with the rod 28, a plurality of wheels 26, 2 at the rear portion of the trailer 10 are arranged in accordance with the rotational displacement of the tractor 12.
6 also displaces and rotates smoothly.

Further, the rotational displacement of the rear steering panel 20 is transmitted to the front steering panel 32 by the connecting rod 30, and the rotation of the front steering panel 32 causes the front wheels 26, 26 also displaces and rotates smoothly.

Further, as shown in FIG. 1, the front steering panel 32 is provided for the purpose of fixing the steering panel even during traveling.
A concave portion is formed in the concave portion, and the convex piece 38 that rotates about the shaft 36 by the expansion and contraction of the fixing cylinder-34 is engaged with the concave portion to stop the rotation of the steering board 32. The other steering device parts are also fixed, and the steering device of the trailer is fixed.

According to the hydraulic piping diagram equipped with the electronic control unit according to the present invention in FIG. 2, the cylinder-1 during steering of the trailer is shown.
A control valve 40 having a characteristic of controlling expansion / contraction displacement of 8 and generating a differential pressure in the output is connected to the cylinder 18 by pipes 42 and 44, and is rotated by the operation of the control valve 40 and the electric motor 46. The hydraulic pump 48 is connected by pipes 50 and 52,
The inlet of the relief valve 54 set to high pressure is connected to the pipe 50, and excess oil flows into the oil tank 56 through the pipe 52 and is parallel to the relief valve 54 and designated as low pressure. -The inlet of the valve 58 is the pipe 50 through the solenoid valve 60.
On the other hand, the output pipes 42, 44 of the control valve 40 are equipped with pressure sensors 62, 64 for detecting the differential pressure at the time of output, and the differential pressure detected by the pressure sensors 62, 64 is used as an electric signal. The electronic control unit 6 is sent to the electronic control unit 66.
6 is configured to send an electric signal to the electric motor 46 and the solenoid valve 60 based on this data.

With the above construction, when a differential pressure is generated in the output of the control valve 40 during steering of the trailer, this differential pressure is detected by the pressure sensors 62 and 64, and the electronic control unit 66 as an electric signal. Based on this data, the electronic control unit 66 speeds up the rotation of the electric motor 46 to send a sufficient amount of oil, and further sends an electric signal to the solenoid valve 60 to set a low pressure. Since the oil does not flow to the released relief valve 58 and the high pressure oil flows to the control valve 40 by the relief valve 54 set to a high pressure, the hydraulic pressure should be generated at the maximum output during the steering of the trailer. Is set, and oil is set to flow through the relief valve 58 which is normally set to a low pressure.
Since the rotation of the electric motor 46 is slowed down, the temperature of the motor rises (the life is short) and the oil temperature rises (oil coater).
It is possible to eliminate problems such as the need for a printer) and large power consumption (the battery goes up, and the life of the dynamo is shortened).

Further, if the fixing switch 68 is turned on, when the fixed cylinder 34 is operated when the steering device is fixed, the switching valve 70 is switched by switching the switching valve 70 even if a differential pressure is not generated between the sensors 62 and 64. It is possible to increase the rotational speed of the motor 46 to generate a sufficient hydraulic pressure, and 72 is a switching valve for stopping the cylinder 18 in that case, 74 is a relay circuit for transmitting a signal at the time of backing, and a sensor 62 , 64, the switching valve 70 can be switched to increase the rotational speed of the motor 46 to generate sufficient hydraulic pressure, and 76 is a battery of the electronic control unit 66.

[0013]

As described above, according to the control device for the steering device in the trailer of the present invention, the hydraulic pressure is generated at the maximum output during steering and normally lower than that during steering. Problems such as temperature rise (short life), oil temperature rise (need oil cooler) and large electric power consumption (battery goes up, dynamo life shortened) Even when the steering device is fixed, the hydraulic pressure can be generated with the maximum output.

[Brief description of drawings]

FIG. 1 shows a state in which a rear wheel of a trailer according to the present embodiment is rotating in response to rotation of a tractor.

FIG. 2 shows a hydraulic piping diagram with an electronic control device according to the invention.

[Explanation of symbols]

 10 Trailer 12 Tractor 14 King pin 16 Hydraulic piping 18 Cylinder 20 Rear steering wheel 22 Axle 24 Rotating arm 26 Wheels 28 Connecting rod 30 Connecting rod 32 Front steering wheel 34 Fixed cylinder 36 Axis 38 Convex piece 40 Control Valve 42 Piping 44 Piping 46 Electric motor 48 Hydraulic pump 50 Piping 52 Piping 54 Relief valve 56 Oil tank 58 Relief valve 60 Solenoid valve 62 Pressure sensor-64 Pressure sensor-66 Electronic control unit 68 Fixing switch 70 switching valve 72 switching valve 74 relay circuit 76 battery-

Claims (1)

[Claims] 1. Wheels are rotatably pivoted on both sides of a rear axle of a trailer that is rotatably connected to a tractor with a kingpin as an axis and travels while being towed, via rotating arms.
A steering mechanism is rotatably pivotally attached to the center of the axle, and a link mechanism is constructed by rotatably connecting the rotating arm and the steering system with a connecting rod, and the rotational displacement of the tractor is hydraulically adjusted. It is converted to the expansion and contraction displacement of the hydraulic cylinder through the pipe, and the expansion and contraction displacement of the hydraulic cylinder is transmitted to the steering wheel at the center of the axle, and the displacement of the steering wheel is transmitted to the left and right rear wheels by the link mechanism. In a steering device of a trailer in which left and right rear wheels are displaced, a control valve having a characteristic of controlling expansion / contraction displacement of the cylinder during steering of the trailer to generate a differential pressure in an output, and the control valve. And two relief valves with different set pressures are connected in parallel in the hydraulic piping that connects the hydraulic pump that rotates by the operation of the electric motor, and the solenoid valve is connected to the relief valve with the lower specified pressure. Are connected in series, and the output of the control valve By providing an electronic control unit that detects the pressure and sends an electric signal to the electric motor and the solenoid valve based on this data, the hydraulic pressure is generated at the maximum output when the trailer is steered. Is a control device for a steering device in a trailer, which is configured to generate a hydraulic pressure lower than that during steering.