Four-wheel center return system for four-wheel drive vehicle

Abstract

The present invention discloses a four-wheel center return system for a four-wheel drive vehicle, comprising: a front steering cylinder for driving a pair of front wheels to steer, a rear steering cylinder for driving a pair of rear wheels to steer, and first to eighth solenoid valves connected to the front steering cylinder and the rear steering cylinder through oil pipes according to a control path; the first to eighth solenoid valves are also connected to an oil pump station through oil pipes and are all connected to an angle control ECU, and the angle control ECU controls the conduction and closing to achieve the front wheel center return, rear wheel center return, four-wheel steering and crab walking. The present invention realizes one-button four-wheel center return. Compared with the prior art, the structure is simple, the difficulty of driver operation is reduced, the service life of the axle is extended, and the abnormal wear of the tire is reduced. In addition, the present invention adopts a front wheel angle sensor and a rear wheel angle sensor to detect the return position of the front wheel and the rear wheel and feed it back to the angle control ECU, and the center return accuracy reaches ±0.3°.

Description

Technical Field

[0001] The invention relates to the technical field of engineering vehicles, and in particular to a four-wheel centering return system for a four-wheel drive vehicle. Background Art

[0002] Intelligent vehicles with automated control are conducive to reducing labor intensity and improving the safety of drivers. At present, the intelligent electronic control system of hydraulic four-wheel drive and four-wheel steering of engineering vehicles based on CAN communication is composed of engine, driving controller, driving state parameter collector, steering angle sensor, angle controller ECU and wiring harness, etc. The angle controller controls the ECU to transmit and process the data collected by driving state parameters.

[0003] Engineering vehicles are composed of a travel system, a steering system, a hydraulic system, an electronic control system and a frame. The travel system is composed of a power mechanism, a travel mechanism, a reducer, etc.

[0004] The hydraulic steering system is mainly composed of two sets of steering mechanisms, hydraulic steering cylinders, connecting oil pipes, etc. The two ends of the hydraulic steering cylinders are connected to rocker arms, which can push the wheels to rotate around the vertical axis of the steering knuckle, thereby realizing four steering modes (front wheel, rear wheel, four-wheel, crab steering).

[0005] At present, the steering mode in engineering vehicles is realized by using a diode plus an electromagnetic switch to control the operation of the corresponding hydraulic solenoid valve and drive the corresponding hydraulic cylinder to realize steering. This requires the addition of many electronic components and has a complex structure.

[0006] In addition, after the four steering modes (front wheel, rear wheel, four-wheel, crab steering), each center return is troublesome and requires two people to cooperate to return to the center. The center return accuracy is also unsatisfactory. The driver needs to operate the steering wheel, and the assistant reminds the driver to turn the steering wheel according to the status of the four wheels. It often takes multiple turns to return the center to the center. The accuracy of the front and rear wheels of the center return will also deviate. Data measurement of the front and rear wheels is required to ensure the center return status and accuracy. The actual operation process is cumbersome, and the deviation of the center return accuracy will seriously affect the driving safety of the vehicle and have a greater impact on the life of the axle and tires. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a four-wheel centering return system for a four-wheel drive vehicle with a simple structure and easy operation, in view of the problem that it is troublesome to return to the center position each time after the existing engineering vehicles turn in four modes (front wheel, rear wheel, four wheels, crab steering).

[0008] The technical problem to be solved by the present invention can be achieved by the following technical solutions:

[0009] A four-wheel center return system for a four-wheel drive vehicle comprises: a front steering cylinder for driving a pair of front wheels to steer, a rear steering cylinder for driving a pair of rear wheels to steer, and a first solenoid valve, a second solenoid valve, a third solenoid valve, a fourth solenoid valve, a fifth solenoid valve, a sixth solenoid valve, a seventh solenoid valve, and an eighth solenoid valve connected to the front steering cylinder and the rear steering cylinder through oil pipes according to a control path; the first solenoid valve, the second solenoid valve, the third solenoid valve, the fourth solenoid valve, the fifth solenoid valve, the sixth solenoid valve, the seventh solenoid valve, and the eighth solenoid valve are also connected to an oil pump station through oil pipes and are all connected to an angle control ECU, and are controlled to be turned on and off by the angle control ECU to achieve front wheel center return, rear wheel center return, four-wheel steering and crab walking.

[0010] In a preferred embodiment of the present invention, the control path is: the first solenoid valve is energized, and the front steering cylinder drives a pair of front wheels to steer; the second solenoid valve is energized, and the rear steering cylinder drives a pair of rear wheels to steer; the first solenoid valve and the second solenoid valve are energized at the same time, and the front steering cylinder drives a pair of front wheels and the rear steering cylinder drives a pair of rear wheels to crab-walk; the first solenoid valve and the third solenoid valve are energized at the same time, and the front steering cylinder drives a pair of front wheels and the rear steering cylinder drives a pair of rear wheels to steer simultaneously; the fourth solenoid valve and the fifth solenoid valve are energized at the same time, and the front steering cylinder drives the left front wheel; the fourth solenoid valve and the sixth solenoid valve are energized at the same time, and the front steering cylinder drives the right front wheel; the fourth solenoid valve and the seventh solenoid valve are energized at the same time, and the rear steering cylinder drives the left rear wheel; the fourth solenoid valve and the eighth solenoid valve are energized at the same time, and the rear steering cylinder drives the right rear wheel.

[0011] In a preferred embodiment of the present invention, the four-wheel center position return signal of the angle control ECU is input through a four-wheel center position return switch.

[0012] In a preferred embodiment of the present invention, the positive poles of the first solenoid valve, the second solenoid valve, the third solenoid valve, the fourth solenoid valve, the fifth solenoid valve, the sixth solenoid valve, the seventh solenoid valve and the eighth solenoid valve are respectively connected to the output pins H1, G1, F1, E1, D1, C1, K1 and J1 of the control signal of the angle control ECU, and the negative poles of the first solenoid valve, the second solenoid valve, the third solenoid valve, the fourth solenoid valve, the fifth solenoid valve, the sixth solenoid valve, the seventh solenoid valve and the eighth solenoid valve are grounded; the positive pole of the power supply of the angle control ECU is connected to the positive pole of the battery through a pair of normally open contacts ZJ1-1 of the relay ZJ, the fuse Z-FU1 and the main power switch, and the negative pole of the battery and the negative pole of the angle control ECU are grounded; the input end of the ignition switch JK is connected to the positive pole of the battery through the fuse F-FU2 and the main power switch, and the ignition switch JK is connected to the positive pole of the battery through the fuse F-FU2 and the main power switch. The output end of the ignition switch JK is connected to the engine ECU; one end of the wire package of the relay ZJ is connected to the output end of the ignition switch JK, and the other end is grounded; the input end of the four-wheel center return switch is connected to the output end of the ignition switch JK, and the output end of the four-wheel center return switch is connected to the four-wheel center return signal input end G4 of the angle control ECU; the positive power supply of the front wheel angle sensor and the positive power supply of the rear wheel angle sensor are connected to the output end of the ignition switch JK, and the positive power supply of the front wheel angle sensor and the negative power supply of the rear wheel angle sensor are grounded; the input end of the four-position conversion switch K2 is connected to the output end of the ignition switch JK; the four output ends of the four-position conversion switch K2 are respectively connected to the front wheel steering signal input end B3, the rear wheel steering signal input end K2, the four-wheel steering signal input end J2, and the crab signal input end H2 of the angle control ECU.

[0013] In a preferred embodiment of the present invention, it also includes a return-to-center indicator light, one end of which is connected to the return-to-center signal output end of the angle control ECU, and the other end of which is connected to the power supply ACC.

[0014] Due to the adoption of the above technical solution, the present invention realizes one-button four-wheel center return. Compared with the prior art, the structure is simple, the difficulty of driver operation is reduced, the service life of the axle is extended, and the abnormal wear of the tire is reduced. In addition, the present invention adopts a front wheel angle sensor and a rear wheel angle sensor to detect the return position of the front wheel and the rear wheel and feed it back to the angle control ECU, and the center return accuracy reaches ±0.3°. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The figure is a schematic diagram of the hydraulic principle of the four-wheel center return system of the four-wheel drive vehicle of the present invention.

[0016] Figure 2 The present invention is a schematic diagram of the electrical principle of the four-wheel center return system of the four-wheel drive vehicle. DETAILED DESCRIPTION

[0017] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0018] See also Figure 1 , a four-wheel center return system for a four-wheel drive vehicle shown in the figure includes: a front steering cylinder 20 for driving the left front wheel 10 and the right front wheel 10a to steer, a rear steering cylinder 40 for driving the left rear wheel 30 and the right rear wheel 30a to steer, and a first solenoid valve YV1, a second solenoid valve YV2, a third solenoid valve YV3, a fourth solenoid valve YV4, a fifth solenoid valve YV5, a sixth solenoid valve YV6, a seventh solenoid valve YV7, and an eighth solenoid valve YV8 connected to the front steering cylinder 20 and the rear steering cylinder 40 through an oil pipe according to a control path; the first solenoid valve YV1, the second solenoid valve YV2, the third solenoid valve YV3, the fourth solenoid valve YV4, the fifth solenoid valve YV5, the sixth solenoid valve YV6, the seventh solenoid valve YV7, and the eighth solenoid valve YV8 are also connected to an oil pump station through an oil pipe and are all connected to an angle control ECU 50, which is controlled by the angle control ECU 50 controls the on and off, and realizes the left front wheel 10, the right front wheel 10a center return, the left rear wheel 30, the right rear wheel 30a center return, four-wheel steering and crab walking.

[0019] See also Figure 2 The positive poles of the first solenoid valve YV1, the second solenoid valve YV2, the third solenoid valve YV3, the fourth solenoid valve YV4, the fifth solenoid valve YV5, the sixth solenoid valve YV6, the seventh solenoid valve YV7 and the eighth solenoid valve YV8 are respectively connected to the output pins H1, G1, F1, E1, D1, C1, K1 and J1 of the control signal of the angle control ECU 50, and the negative poles of the first solenoid valve YV1, the second solenoid valve YV2, the third solenoid valve YV3, the fourth solenoid valve YV4, the fifth solenoid valve YV5, the sixth solenoid valve YV6, the seventh solenoid valve YV7 and the eighth solenoid valve YV8 are grounded.

[0020] The positive pole of the power supply of the angle control ECU 50 is connected to the positive pole of the battery E through a pair of normally open contacts ZJ1-1 of the relay ZJ, the fuse Z-FU1, and the main power switch, and the negative pole of the battery E and the negative pole of the angle control ECU 50 are grounded.

[0021] The input end of the ignition switch JK is connected to the positive pole of the battery E through the fuse F-FU2 and the main power switch, and the output end of the ignition switch JK is connected to the engine ECU; one end of the wire package of the relay ZJ is connected to the output end of the ignition switch JK, and the other end is grounded.

[0022] The input end of the four-wheel center position return switch SB1 is connected to the output end of the ignition switch JK, and the output end of the four-wheel center position return switch SB1 is connected to the four-wheel center position return signal input end G4 of the angle control ECU 50; the positive power supply of the front wheel angle sensor EPS1 and the positive power supply of the rear wheel angle sensor EPS2 are connected to the output end of the ignition switch JK, and the positive power supply of the front wheel angle sensor EPS1 and the negative power supply of the rear wheel angle sensor EPS2 are grounded; the input end of the four-position conversion switch K2 is connected to the output end of the ignition switch JK; the four output ends of the four-position conversion switch K2 are respectively connected to the front wheel steering signal input end B3, the rear wheel steering signal input end K2, the four-wheel steering signal input end J2, and the crab walking signal input end H2 of the angle control ECU 50. One end of the return indicator light HL1 is connected to the return signal output end of the angle control ECU 50, and the other end of the return indicator light HL1 is connected to the power supply ACC.

[0023] When the four-position conversion switch K2 is switched to the front wheel steering position, the first electromagnetic YV1 is energized, and the front steering cylinder 20 drives the left front wheel 10 and the right front wheel 10a to steer.

[0024] When the four-position conversion switch K2 is switched to the rear wheel steering position, the second electromagnetic YV2 is energized, and the rear steering cylinder 40 drives the left rear wheel 30 and the right rear wheel 30a to steer.

[0025] When the four-position conversion switch K2 is switched to the four-wheel steering position, the first solenoid valve YV1 and the third solenoid valve YV3 are energized at the same time, and the front steering cylinder 20 drives the left front wheel 10 and the right front wheel 10a and the rear steering cylinder 40 drives the left rear wheel 30 and the right rear wheel 30a to steer simultaneously.

[0026] When the four-position switch K2 is switched to the crab position, the first solenoid valve YV1 and the second solenoid valve YV2 are energized at the same time, the front steering cylinder 20 drives the left front wheel 10 and the right front wheel 10a and the rear steering cylinder 40 drives the left rear wheel 30 and the right rear wheel 30a to crab move.

[0027] If center return is required, press the four-wheel center return switch SB1 to input the center return signal to the angle control ECU 50. First, the angle control ECU 50 energizes the fourth solenoid valve YV4 and the fifth solenoid valve YV5 at the same time, and the front steering cylinder 20 drives the left front wheel 10 back to the center; then the angle control ECU 50 energizes the fourth solenoid valve YV4 and the sixth solenoid valve YV6 at the same time, and the front steering cylinder 20 drives the right front wheel 10a back to the center. Then the angle control ECU 50 energizes the fourth solenoid valve YV4 and the seventh solenoid valve YV7 at the same time, and the rear steering cylinder 40 drives the left rear wheel 30 back to the center. Finally, the angle control ECU 50 energizes the fourth solenoid valve YV4 and the eighth solenoid valve YV8 at the same time, and the rear steering cylinder 40 drives the right rear wheel 30a back to the center.

[0028] When the four-wheel center return switch SB1 is pressed, the angle control ECU 50 turns on the return indicator light HL1. During the center return process, the front wheel angle sensor EPS1 and the rear wheel angle sensor EPS2 detect the positions of the left front wheel 10, the right front wheel 10a, the left rear wheel 30, and the right rear wheel 30a and feed back the position signals to the angle control ECU 50.

Claims

1. A four-wheel center return system for a four-wheel drive vehicle, characterized in that: include: A front steering cylinder driving a pair of front wheels to steer and a rear steering cylinder driving a pair of rear wheels to steer, and a first solenoid valve, a second solenoid valve, a third solenoid valve, a fourth solenoid valve, a fifth solenoid valve, a sixth solenoid valve, a seventh solenoid valve, and an eighth solenoid valve connected to the front steering cylinder and the rear steering cylinder through oil pipes according to a control path; the first solenoid valve, the second solenoid valve, the third solenoid valve, the fourth solenoid valve, the fifth solenoid valve, the sixth solenoid valve, the seventh solenoid valve, and the eighth solenoid valve are also connected to an oil pump station through oil pipes and are all connected to an angle control ECU, and the angle control ECU controls conduction and closing to achieve front wheel center return, rear wheel center return, four-wheel steering and crab walking; The four-wheel center position return signal of the angle control ECU is input through a four-wheel center position return switch; The positive poles of the first solenoid valve, the second solenoid valve, the third solenoid valve, the fourth solenoid valve, the fifth solenoid valve, the sixth solenoid valve, the seventh solenoid valve and the eighth solenoid valve are respectively connected to the output pins H1, G1, F1, E1, D1, C1, K1 and J1 of the control signal of the angle control ECU, and the negative poles of the first solenoid valve, the second solenoid valve, the third solenoid valve, the fourth solenoid valve, the fifth solenoid valve, the sixth solenoid valve, the seventh solenoid valve and the eighth solenoid valve are grounded; the positive pole of the power supply of the angle control ECU is connected to the positive pole of the battery through a pair of normally open contacts ZJ1-1 of the relay ZJ, the fuse Z-FU1 and the main power switch, and the negative pole of the battery and the negative pole of the angle control ECU are grounded; the input end of the ignition switch JK is connected to the positive pole of the battery through the fuse F-FU2 and the main power switch, and the output end of the ignition switch JK is connected to the positive pole of the battery. The output end is connected to the engine ECU; one end of the wire package of the relay ZJ is connected to the output end of the ignition switch JK, and the other end is grounded; the input end of the four-wheel center return switch is connected to the output end of the ignition switch JK, and the output end of the four-wheel center return switch is connected to the four-wheel center return signal input end G4 of the angle control ECU; the positive power supply of the front wheel angle sensor and the positive power supply of the rear wheel angle sensor are connected to the output end of the ignition switch JK, and the positive power supply of the front wheel angle sensor and the negative power supply of the rear wheel angle sensor are grounded; the input end of the four-position conversion switch K2 is connected to the output end of the ignition switch JK; the four output ends of the four-position conversion switch K2 are respectively connected to the front wheel steering signal input end B3, the rear wheel steering signal input end K2, the four-wheel steering signal input end J2, and the crab signal input end H2 of the angle control ECU; The control path is: the first solenoid valve is energized, and the front steering cylinder drives a pair of front wheels to steer; the second solenoid valve is energized, and the rear steering cylinder drives a pair of rear wheels to steer; the first solenoid valve and the second solenoid valve are energized at the same time, and the front steering cylinder drives a pair of front wheels and the rear steering cylinder drives a pair of rear wheels to crab-walk; the first solenoid valve and the third solenoid valve are energized at the same time, and the front steering cylinder drives a pair of front wheels and the rear steering cylinder drives a pair of rear wheels to steer simultaneously; the fourth solenoid valve and the fifth solenoid valve are energized at the same time, and the front steering cylinder drives the left front wheel; the fourth solenoid valve and the sixth solenoid valve are energized at the same time, and the front steering cylinder drives the right front wheel; the fourth solenoid valve and the seventh solenoid valve are energized at the same time, and the rear steering cylinder drives the left rear wheel; the fourth solenoid valve and the eighth solenoid valve are energized at the same time, and the rear steering cylinder drives the right rear wheel.

2. A four-wheel center return system for a four-wheel drive vehicle as claimed in claim 1, characterized in that: It also includes a return indicator light, one end of which is connected to the return signal output end of the angle control ECU, and the other end of which is connected to the power supply ACC.

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