CN117021939A - Hydraulic system of electrohydraulic four-wheel drive transportation robot and working method thereof - Google Patents

Abstract

The invention provides an electrohydraulic four-wheel-drive transport robot hydraulic system and a working method thereof, wherein a permanent magnet motor in the system is connected with a closed axial plunger pump, and the closed axial plunger pump forms a closed loop with a plurality of wheel motors through a motor valve group; the permanent magnet motor is connected with a gear pump, and the gear pump is connected with a plurality of wheel edge steering mechanisms through a steering mechanism valve group and a steering plunger cylinder group; the permanent magnet motor drives a closed axial plunger pump and a gear pump; the control element adjusts the motor valve group and the steering mechanism valve group based on the moving steering instruction; the closed axial plunger pump sends oil in an oil tank to a corresponding wheel side motor through a motor valve group so as to drive the wheel side motor; the gear pump sends oil in the oil tank to the corresponding steering plunger cylinder group through the steering mechanism valve group to drive the wheel side steering mechanism, so that the robot moves and steers according to the moving steering instruction. The system according to the invention improves steering sensitivity.

Description

Hydraulic system of electrohydraulic four-wheel drive transportation robot and working method thereof

Technical Field

The invention relates to the technical field of hydraulic systems and working methods thereof, in particular to an electrohydraulic four-wheel drive transport robot hydraulic system and a working method thereof.

Background

Research on vehicles which are suitable for complex non-structural terrains and have good maneuverability is continuously carried out by domestic and foreign researchers, and great progress is made. At present, vehicles have various transmission modes, mainly comprising electric, hydraulic and pneumatic, and hydraulic transmission is widely researched and applied due to high transmission power, large inertia ratio, overload protection capability, wider stepless speed regulation range and flexible layout.

For example, chinese patent application publication No. CN115593222a discloses a four-wheel drive hydrostatic traveling system and a vehicle, in which a hydrostatic motor is used as a driving device for traveling components, and the output displacement and the rotation speed of the hydrostatic motor are controlled by different working positions, so that the vehicle driving components such as a conventional torque converter and a speed reducer are replaced, the overall height of the vehicle can be effectively reduced, and the adaptability of the vehicle to some low mines can be effectively improved. The hydraulic system of the patent requires more hydrostatic motors, has higher cost and is not sensitive enough to turn.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems in the related art to some extent.

Therefore, the invention provides an electrohydraulic four-wheel drive transportation robot hydraulic system and a working method thereof, and mainly aims to reduce the turning radius so as to improve the steering sensitivity.

The first aspect of the invention provides an electrohydraulic four-wheel drive transportation robot hydraulic system, which comprises a permanent magnet motor, a closed axial plunger pump, a gear pump, a plurality of wheel motors, a motor valve group, a plurality of wheel steering mechanisms, a steering plunger cylinder group, a steering mechanism valve group, an oil tank and a control element;

the permanent magnet motor is connected with the closed axial plunger pump, and the closed axial plunger pump and the wheel side motors form a closed loop through the motor valve group; the permanent magnet motor is connected with the gear pump, and the gear pump is connected with the plurality of wheel steering mechanisms through the steering mechanism valve group and the steering plunger cylinder group;

the oil tank is used for storing oil; the permanent magnet motor is used for driving the closed axial plunger pump and the gear pump; the closed axial plunger pump is used for sending oil in the oil tank to the motor valve group; the gear pump is used for sending oil in the oil tank to the steering mechanism valve group; the control element is used for adjusting the motor valve group and the steering mechanism valve group based on a moving steering instruction; the motor valve group is used for sending oil to the corresponding wheel side motors based on the control of the control element so as to drive the wheel side motors, and therefore the robot moves according to the movement steering instruction; the steering mechanism valve group is used for sending oil to the corresponding steering plunger cylinder group based on the control of the control element so as to drive the wheel side steering mechanism, and therefore the robot is steered according to the moving steering instruction.

In the hydraulic system of the electro-hydraulic four-wheel-drive transport robot provided by the first aspect of the invention, the plurality of wheel-side motors are four wheel-side motors, the motor valve group comprises four electromagnetic directional valves, and each electromagnetic directional valve controls a separate wheel-side motor.

In the hydraulic system of the electro-hydraulic four-drive transportation robot provided by the first aspect of the invention, the closed axial plunger pump comprises a supplementary oil pump, and the supplementary oil pump is used for updating the oil liquid of the closed loop.

In the hydraulic system of the electro-hydraulic four-wheel-drive transportation robot provided by the first aspect of the invention, the plurality of wheel-side steering mechanisms are four wheel-side steering mechanisms, the steering mechanism valve group comprises four electromagnetic proportional reversing valves, the steering plunger cylinder group comprises four steering plunger cylinders, each electromagnetic proportional reversing valve controls a separate steering plunger cylinder, and each steering plunger cylinder controls a separate wheel-side steering mechanism.

In the hydraulic system of the electro-hydraulic four-wheel-drive transportation robot provided by the first aspect of the invention, the steering mechanism valve group further comprises an electromagnetic switch valve and an overflow valve, the hydraulic system further comprises a one-way valve, the wheel steering mechanism is connected with the oil tank through the electromagnetic switch valve, the one-way valve and the oil tank, and the overflow valve is connected with the electromagnetic switch valve in parallel.

In the hydraulic system of the electro-hydraulic four-wheel-drive transportation robot provided by the first aspect of the invention, the hydraulic system further comprises a coarse filter and a fine filter, and the oil tank is connected with the closed axial plunger pump through the coarse filter and the fine filter.

In the hydraulic system of the electro-hydraulic four-wheel-drive transportation robot provided by the first aspect of the invention, the hydraulic system further comprises a plate heat exchanger and an air filter, wherein the plate heat exchanger is used for exchanging heat generated by the closed loop in operation so as to realize cooling, and the air filter is used for cleaning oil in an oil way.

In the hydraulic system of the electro-hydraulic four-wheel-drive transportation robot provided by the first aspect of the invention, the hydraulic system further comprises a liquid level thermometer and a liquid level thermometer sensor, and the liquid level thermometer sensor are used for detecting the liquid level and the oil temperature of the oil tank in real time.

The second aspect of the invention provides a working method of the hydraulic system of the electrohydraulic four-wheel drive transportation robot, which comprises the following steps:

controlling the permanent magnet motor to start, and driving the closed axial plunger pump and the gear pump by using the permanent magnet motor;

the control element receives a moving steering instruction and adjusts the motor valve group and the steering mechanism valve group based on the moving steering instruction;

the closed axial plunger pump sends oil in an oil tank to the motor valve group, and sends the oil to the corresponding wheel side motor through the motor valve group so as to drive the wheel side motor, so that the robot moves according to the movement steering instruction;

the gear pump sends oil in the oil tank to the steering mechanism valve group, and sends the oil to the corresponding steering plunger cylinder group through the steering mechanism valve group so as to drive the wheel-side steering mechanism, thereby enabling the robot to steer according to the moving steering instruction.

In the working method of the hydraulic system of the electrohydraulic four-wheel drive transportation robot provided by the second aspect of the invention, the moving steering instruction comprises five instructions of a forward running mode, a steering mode, a in-situ turning mode, a tilting mode and a traversing mode.

In one or more aspects of the invention, the system includes a permanent magnet motor, a closed axial plunger pump, a gear pump, a plurality of wheel motors, a motor valve bank, a plurality of wheel steering mechanisms, a steering plunger cylinder bank, a steering mechanism valve bank, an oil tank, and a control element; the permanent magnet motor is connected with a closed axial plunger pump, and the closed axial plunger pump and a plurality of wheel motors form a closed loop through a motor valve group; the permanent magnet motor is connected with a gear pump, and the gear pump is connected with a plurality of wheel edge steering mechanisms through a steering mechanism valve group and a steering plunger cylinder group; the oil tank is used for storing oil; the permanent magnet motor is used for driving the closed axial plunger pump and the gear pump; the closed axial plunger pump is used for sending oil in the oil tank to the motor valve group; the gear pump is used for conveying oil in the oil tank to the steering mechanism valve group; the control element is used for adjusting the motor valve group and the steering mechanism valve group based on the moving steering instruction; the motor valve group is used for sending oil to the corresponding wheel side motors based on the control of the control element so as to drive the wheel side motors, and therefore the robot moves according to the movement steering instruction; the steering mechanism valve group is used for sending oil to the corresponding steering plunger cylinder group based on the control of the control element so as to drive the wheel side steering mechanism, and therefore the robot steers according to the moving steering instruction. Under the condition, the closed axial plunger pump forms a closed loop with a plurality of wheel motors through the motor valve group, and the size of the oil tank can be reduced by adopting a closed loop mode, so that the hydraulic system can meet the frame requirement more. In addition, the motor valve group is utilized to respectively control the plurality of wheel side motors, and the steering mechanism valve group is utilized to respectively control the plurality of wheel side steering mechanisms, so that the turning radius can be reduced, and the steering sensitivity is improved.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The foregoing and/or additional aspects and advantages of the invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

FIG. 1 shows a block diagram of an electrohydraulic four-wheel drive transport robot hydraulic system provided by an embodiment of the invention;

fig. 2 shows a connection schematic diagram of an electrohydraulic four-wheel drive transportation robot hydraulic system provided by an embodiment of the invention;

fig. 3 shows a motion function implementation diagram of an electrohydraulic four-wheel drive transport robot provided by an embodiment of the invention;

FIG. 4 shows a flow chart of a working method of an electrohydraulic four-wheel drive transportation robot hydraulic system provided by an embodiment of the invention;

reference numerals illustrate:

the 1-hydraulic system comprises a permanent magnet motor, a 2-closed axial plunger pump, a 3-motor valve bank, a 4-left front wheel motor, a 5-right rear wheel motor, a 6-right front wheel motor, a 7-left rear wheel motor, an 8-left front electromagnetic directional valve, a 9-right rear electromagnetic directional valve, a 10-right front electromagnetic directional valve, a 11-left rear electromagnetic directional valve, a 12-steering mechanism valve bank, a 13-left front wheel steering mechanism, a 14-left front steering plunger cylinder, a 15-left front electromagnetic proportional directional valve, a 16-right front wheel steering mechanism, a 17-right front steering plunger cylinder, a 18-right front electromagnetic proportional directional valve, a 19-left rear wheel steering mechanism, a 20-left rear steering plunger cylinder, a 21-left rear electromagnetic proportional directional valve, a 22-right rear wheel steering mechanism, a 23-right rear steering plunger cylinder, a 24-right rear electromagnetic proportional directional valve, a 25-one-way valve, a 26-electromagnetic switch valve, a 27-overflow valve, a 28-oil tank, a 29-coarse filter, a 30-fine filter, a 31-plate type heat exchanger, a liquid level sensor and a liquid level sensor, a 35-air temperature sensor.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with embodiments of the invention. Rather, they are merely examples of apparatus and methods consistent with aspects of embodiments of the invention as detailed in the accompanying claims.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise. It should also be understood that the term "and/or" as used in this disclosure refers to and encompasses any or all possible combinations of one or more of the associated listed items.

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.

The invention provides an electrohydraulic four-wheel drive transportation robot hydraulic system and a working method thereof, and mainly aims to reduce turning radius so as to improve steering sensitivity.

In a first embodiment, fig. 1 shows a block diagram of an electrohydraulic four-drive transport robot hydraulic system according to an embodiment of the present invention. The hydraulic system of the electrohydraulic four-wheel drive transportation robot can be simply called as a hydraulic system. As shown in fig. 1, the hydraulic system of the electrohydraulic four-wheel drive transportation robot comprises a permanent magnet motor, a closed axial plunger pump, a gear pump, a plurality of wheel motors, a motor valve group, a plurality of wheel steering mechanisms, a steering plunger cylinder group, a steering mechanism valve group, an oil tank and a control element. The permanent magnet motor is connected with a closed axial plunger pump, and the closed axial plunger pump and a plurality of wheel motors form a closed loop through a motor valve group; the permanent magnet motor is connected with the gear pump, and the gear pump is connected with a plurality of wheel edge steering mechanisms through the steering mechanism valve group and the steering plunger cylinder group.

In this embodiment, the oil tank is used to store oil.

In this embodiment, a permanent magnet motor is used to drive a closed axial plunger pump and a gear pump. Specifically, the permanent magnet motor is simultaneously connected with the control element, the closed axial plunger pump and the gear pump (refer to fig. 1), and the starting of the permanent magnet motor is controlled by the control element. When the permanent magnet motor is started, the permanent magnet motor drives the closed axial plunger pump and the gear pump.

In this embodiment, the closed axial plunger pump drives a plurality of rim motors and constitutes a closed circuit. Specifically, the closed axial plunger pump is connected with the oil tank and the motor valve group simultaneously (refer to fig. 1). The closed axial plunger pump forms a closed loop with a plurality of wheel motors through the motor valve group. When the closed axial plunger pump is driven, the closed axial plunger pump sends oil in the oil tank to the motor valve group so as to drive the corresponding wheel motor.

In this embodiment, the closed axial plunger pump includes a makeup pump for renewing the oil of the closed circuit.

In this embodiment, the motor valve group is used for sending oil to the corresponding wheel side motors based on the control of the control element so as to drive the wheel side motors, and therefore the robot moves according to the movement steering command. Specifically, the motor valve block is simultaneously connected with the control element and the plurality of wheel motors (see fig. 1). If the plurality of wheel motors are four wheel motors, the motor valve group comprises four electromagnetic directional valves, and each electromagnetic directional valve is connected with a single wheel motor. Each electromagnetic directional valve controls a separate one of the rim motors. Therefore, the function of adjusting different speed gears and reducing turning radius can be realized.

Wherein, each electromagnetic directional valve includes middle position, left bit and right bit. When the electromagnetic directional valve is in the middle position under the control of the control element, oil does not circulate (i.e. does not enter the wheel side motor), and the corresponding wheel side motor does not work. When the electromagnetic directional valve is in left or right position under the control of the control element, oil enters the corresponding wheel motor, and the wheel motor retreats or advances.

In this embodiment, the gear pump is used to send oil from the oil tank to the steering mechanism valve block. Specifically, the gear pump is simultaneously connected with the oil tank and the steering mechanism valve group (see fig. 1), and when the gear pump is driven, the gear pump sends oil in the oil tank to the steering mechanism valve group.

In this embodiment, the steering mechanism valve group is used for delivering oil to the corresponding steering plunger cylinder group based on the control of the control element so as to drive the wheel-side steering mechanism, and thus the robot is steered according to the moving steering command. Specifically, the steering mechanism valve block is connected to the control element, and the steering mechanism valve block is also connected to the steering plunger cylinder block (see fig. 1). If the plurality of wheel steering mechanisms are four wheel steering mechanisms, the steering mechanism valve group comprises four electromagnetic proportional reversing valves, the steering plunger cylinder group comprises four steering plunger cylinders, and each electromagnetic proportional reversing valve is connected with one wheel steering mechanism through one steering plunger cylinder. Each electromagnetic proportional reversing valve controls a separate one of the steering plunger cylinders, and each steering plunger cylinder controls a separate one of the wheel-side steering mechanisms. The four electromagnetic proportional reversing valves are regulated by the control element, so that oil enters the corresponding steering plunger cylinders to respectively control the four steering plunger cylinders, thereby controlling the four wheel steering mechanisms and realizing the steering function. Therefore, the functions of respectively controlling different turning angles of the four tires and reducing turning radius can be realized.

In this embodiment, the control element is used to adjust the motor valve block and the steering mechanism valve block based on the movement steering command.

Specifically, the movement steering instruction includes five instructions of a forward running mode, a steering mode, a turn-around-in-place mode, a tilting mode and a traversing mode. But the instruction type of the movement steering instruction in the present embodiment is not limited thereto.

Each instruction comprises a corresponding control rule, the control element recognizes the corresponding control rule (described in detail later) after receiving the moving steering instruction, and controls each electromagnetic directional valve in the motor valve group to be in a corresponding middle position, a left position or a right position based on the control rule, and further controls the electromagnetic proportional directional valve in the steering mechanism valve group. Thus, the forward movement, steering, in-situ turning around, tilting or transverse movement corresponding to the movement steering instruction can be realized.

In this embodiment, the steering mechanism valve group further includes an electromagnetic switch valve and an overflow valve, the hydraulic system further includes a one-way valve, the wheel steering mechanism is connected to the oil tank through the electromagnetic switch valve, the one-way valve, and the overflow valve is connected in parallel with the electromagnetic switch valve.

In this embodiment, the hydraulic system further includes a coarse filter and a fine filter, and the oil tank is connected to the closed axial plunger pump through the coarse filter and the fine filter.

In the embodiment, the hydraulic system further comprises a plate heat exchanger and an air filter, wherein the plate heat exchanger is used for exchanging heat generated by the closed loop during operation so as to realize cooling, the air filter is used for cleaning oil in an oil way,

in this embodiment, the hydraulic system further includes a liquid level thermometer and a liquid level thermometer sensor for detecting the liquid level and the oil temperature of the oil tank in real time.

Taking four wheel motors and four wheel steering mechanisms as examples, fig. 2 shows a connection schematic diagram of an electrohydraulic four-wheel-drive transportation robot hydraulic system provided by the embodiment of the invention.

As shown in fig. 2, the hydraulic system comprises a permanent magnet motor 1, a closed axial plunger pump 2, a motor valve group 3, a left front wheel motor 4, a right rear wheel motor 5, a right front wheel motor 6 and a left rear wheel motor 7. The motor valve group 3 comprises a left front electromagnetic directional valve 8, a right rear electromagnetic directional valve 9, a right front electromagnetic directional valve 10 and a left rear electromagnetic directional valve 11. The hydraulic system further includes a steering mechanism valve group 12, a left front wheel side steering mechanism 13, a left front steering plunger cylinder 14, a right front wheel side steering mechanism 16, a right front steering plunger cylinder 17, a left rear wheel side steering mechanism 19, a left rear steering plunger cylinder 20, a right rear wheel side steering mechanism 22, and a right rear steering plunger cylinder 23. The steering mechanism valve group 12 includes a front left electromagnetic proportional directional valve 15, a front right electromagnetic proportional directional valve 18, a rear left electromagnetic proportional directional valve 21, a rear right electromagnetic proportional directional valve 24, an electromagnetic on-off valve 26, and an overflow valve 27. The hydraulic system further comprises a non-return valve 25, a tank 28, a coarse filter 29, a fine filter 30, a plate heat exchanger 31, an air filter 32, a liquid level thermometer 33, a liquid level thermometer sensor 34 and a gear pump 35.

As shown in fig. 2, the permanent magnet motor 1 is connected with a closed axial plunger pump 2, the closed axial plunger pump 2 is respectively connected with a left front electromagnetic directional valve 8, a right rear electromagnetic directional valve 9, a right front electromagnetic directional valve 10 and a left rear electromagnetic directional valve 11, the left front electromagnetic directional valve 8 is connected with a left front wheel motor 4, the right rear electromagnetic directional valve 9 is connected with a right rear wheel motor 5, the right front electromagnetic directional valve 10 is connected with a right front wheel motor 6, and the left rear electromagnetic directional valve 11 is connected with a left rear wheel motor 7. The permanent magnet motor 1 is connected with a gear pump 35, the gear pump 35 is connected with a left front steering plunger cylinder 14 through a left front electromagnetic proportional reversing valve 15 to control a left front wheel steering mechanism 13, the gear pump 35 is connected with a right front steering plunger cylinder 17 through a right front electromagnetic proportional reversing valve 18 to control a right front wheel steering mechanism 16, the gear pump 35 is connected with a left rear steering plunger cylinder 20 through a left rear electromagnetic proportional reversing valve 21 to control a left rear wheel steering mechanism 19, and the gear pump 35 is connected with a right rear steering plunger cylinder 23 through a right rear electromagnetic proportional reversing valve 24 to control a right rear wheel steering mechanism 22.

Wherein, the closed axial plunger pump 2 and four wheel motors form a closed loop through the motor valve group 3, and the closed loop is supplied with oil by the oil tank 28. The oil output from the oil tank 28 passes through the coarse filter 29 and the fine filter 30, enters the closed-circuit closed-type axial plunger pump 2 and the gear pump 35 of the closed circuit through the S port, thereby entering the corresponding actuator (i.e., the wheel motor and the wheel steering mechanism), and returns to the oil tank 28. The oil enters the motor valve group 3 from an A port of the closed axial plunger pump 2, the motor valve group 3 is controlled by a control element, if the left front electromagnetic directional valve 8, the right rear electromagnetic directional valve 9, the right front electromagnetic directional valve 10 and the left rear electromagnetic directional valve 11 are all in the middle position, the oil does not circulate, the wheel motors do not work, the transportation robot is static, the left front electromagnetic directional valve 8, the right rear electromagnetic directional valve 9, the right front electromagnetic directional valve 10 and the left rear electromagnetic directional valve 11 can be controlled to enable the oil to enter the four wheel motors, the functions of the robot retreating and the like are realized, and the oil for driving the wheel motors is finally gathered to a B port of the closed axial plunger pump 2 and finally returns to the oil tank 28; meanwhile, the permanent magnet motor 1 drives the gear pump 35, oil enters the steering mechanism valve group 12 from the P port, four electromagnetic proportional reversing valves are regulated by a control element to respectively control four steering plunger cylinders and four wheel-side steering mechanisms, the steering function is realized, and the oil for the driving wheel-side steering mechanisms finally returns to the oil tank 28 through the T port of the steering mechanism valve group 12 and the one-way valve 25.

In addition, the plate heat exchanger 31 can exchange heat generated in the closed circuit operation rapidly to cool, the air filter 32 further cleans oil in an oil way, and the liquid level thermometer 33 and the liquid level thermometer sensor 34 can realize real-time observation of the liquid level and the oil temperature of the oil tank.

Taking five instructions of a forward running mode, a steering mode, an in-situ turning mode, an oblique shifting mode and a transverse shifting mode as examples, fig. 3 shows a motion function implementation diagram of an electrohydraulic four-wheel-drive transport robot provided by the embodiment of the invention. With the hydraulic system shown in fig. 2, after the control element receives five moving steering instructions of a forward running mode, a steering mode, a turning around in place mode, a tilting mode and a traversing mode respectively, the motor valve group and the steering mechanism valve group are adjusted based on control rules corresponding to the various moving steering instructions, so that the forward running, steering, turning around in place, tilting and traversing functions shown in fig. 3 are realized.

The specific working process is as follows:

1) If the received moving steering instruction is a forward mode instruction, the permanent magnet motor 1 drives the closed axial plunger pump 2, the left front electromagnetic directional valve 8 is switched to the right position, oil enters the left front electromagnetic directional valve 8 through the port P1, enters the left front wheel motor 4 from the port A, flows out of the left front wheel motor 4 from the port B, returns to the closed axial plunger pump 2 through the port T1, the right rear electromagnetic directional valve 9 is switched to the right position, oil enters the right rear electromagnetic directional valve 9 through the port P2, enters the right rear wheel motor 5 from the port A, flows out of the right rear wheel motor 5 from the port B, and returns to the closed axial plunger pump 2 through the port T2; the right front electromagnetic directional valve 10 is switched to the left position, oil flows through the right front electromagnetic directional valve 10 from the port P3, enters the right front wheel motor 6 from the port B, flows out of the right front wheel motor 6 from the port A, returns to the closed axial plunger pump 2 from the port T3, the left rear electromagnetic directional valve 11 is switched to the left position, oil flows through the left rear electromagnetic directional valve 11 from the port P4, enters the left rear wheel motor 7 from the port B, flows out of the left rear wheel motor 7 from the port A, and returns to the closed axial plunger pump 2 from the port T4; at this time, the gear pump 35 is not operated, and the robot realizes the forward movement function shown in fig. 3 (a);

2) If the received moving steering instruction is a steering mode instruction, the permanent magnet motor 1 drives the closed axial plunger pump 2, the left front electromagnetic directional valve 8 is switched to the right position, oil enters the left front wheel motor 4 from the port P1 through the left front electromagnetic directional valve 8, flows out of the left front wheel motor 4 from the port B, returns to the closed axial plunger pump 2 through the port T1, the right rear electromagnetic directional valve 9 is switched to the left position, oil enters the right rear wheel motor 5 from the port A through the right rear electromagnetic directional valve 9 from the port P2, flows out of the right rear wheel motor 5 from the port B, and returns to the closed axial plunger pump 2 through the port T2; the right front electromagnetic directional valve 10 is switched to the left position, oil flows through the right front electromagnetic directional valve 10 from the port P3, enters the right front wheel motor 6 from the port B, flows out of the right front wheel motor 6 from the port A, returns to the closed axial plunger pump 2 from the port T3, the left rear electromagnetic directional valve 11 is switched to the left position, oil flows through the left rear electromagnetic directional valve 11 from the port P4, enters the left rear wheel motor 7 from the port B, flows out of the left rear wheel motor 7 from the port A, and returns to the closed axial plunger pump 2 from the port T4; meanwhile, the permanent magnet motor 1 drives the gear pump 35, oil flows through the P port to enter the steering mechanism valve group 12, wherein the left front electromagnetic proportional reversing valve 15 is reversed to the left position, the right front electromagnetic proportional reversing valve 18 is reversed to the left position, the left rear electromagnetic proportional reversing valve 21 is reversed to the right position, the right rear electromagnetic proportional reversing valve 24 is reversed to the right position, the oil enters the corresponding steering plunger cylinder through the four electromagnetic proportional reversing valves so as to enter the four wheel steering mechanisms, and then returns to the oil tank 28 through the electromagnetic switch valve 26 and the one-way valve 25, and the robot achieves the steering function shown in (b) of fig. 3;

3) If the received movement steering instruction is an in-situ turning-around mode instruction, the permanent magnet motor 1 drives the closed axial plunger pump 2, the left front electromagnetic directional valve 8 is switched to the right position, oil enters the left front wheel motor 4 from the port P1 through the left front electromagnetic directional valve 8, flows out of the left front wheel motor 4 from the port B, returns to the closed axial plunger pump 2 through the port T1, the right rear electromagnetic directional valve 9 is switched to the left position, oil enters the right rear wheel motor 5 from the port P2 through the right rear electromagnetic directional valve 9, flows out of the right rear wheel motor 5 from the port A, and returns to the closed axial plunger pump 2 through the port T2; the right front electromagnetic directional valve 10 is switched to the left position, oil flows through the right front electromagnetic directional valve 10 from the port P3, enters the right front wheel motor 6 from the port B, flows out of the right front wheel motor 6 from the port A, returns to the closed axial plunger pump 2 from the port T3, the left rear electromagnetic directional valve 11 is switched to the right position, oil flows into the left rear wheel motor 7 from the port P4 through the left rear electromagnetic directional valve 11 from the port A, flows out of the left rear wheel motor 7 from the port B, and returns to the closed axial plunger pump 2 from the port T4; meanwhile, the permanent magnet motor 1 drives the gear pump 35, oil flows through the P port to enter the steering mechanism valve group 12, wherein the left front electromagnetic proportional reversing valve 15 is reversed to the left position, the right front electromagnetic proportional reversing valve 18 is reversed to the right position, the left rear electromagnetic proportional reversing valve 21 is reversed to the right position, the right rear electromagnetic proportional reversing valve 24 is reversed to the left position, the oil enters the steering plunger cylinder through the four electromagnetic proportional reversing valves so as to enter the four wheel steering mechanisms, and then returns to the oil tank 28 through the electromagnetic switch valve 26 and the one-way valve 25, so that the robot realizes the in-situ turning function shown in (c) of fig. 3;

4) If the received movement steering instruction is an oblique movement mode instruction, the permanent magnet motor 1 drives the closed axial plunger pump 2, the left front electromagnetic directional valve 8 is switched to the right position, oil enters the left front wheel motor 4 from the port P1 through the left front electromagnetic directional valve 8, flows out of the left front wheel motor 4 from the port B, returns to the closed axial plunger pump 2 through the port T1, the right rear electromagnetic directional valve 9 is switched to the right position, oil enters the right rear wheel motor 5 from the port A through the right rear electromagnetic directional valve 9 from the port P2, flows out of the right rear wheel motor 5 from the port B, and returns to the closed axial plunger pump 2 through the port T2; the right front electromagnetic directional valve 10 is switched to the left position, oil flows through the right front electromagnetic directional valve 10 from the port P3, enters the right front wheel motor 6 from the port B, flows out of the right front wheel motor 6 from the port A, returns to the closed axial plunger pump 2 from the port T3, is switched to the left position by the left rear electromagnetic directional valve 11, enters the left rear wheel motor 7 from the port B through the left rear electromagnetic directional valve 11 from the port P4, flows out of the left rear wheel motor 7 from the port A, and returns to the closed axial plunger pump 2 from the port T4; meanwhile, the permanent magnet motor 1 drives the gear pump 35, oil flows through the P port to enter the steering mechanism valve group 12, wherein the left front electromagnetic proportional reversing valve 15 is reversed to the left position, the right front electromagnetic proportional reversing valve 18 is reversed to the left position, the left rear electromagnetic proportional reversing valve 21 is reversed to the right position, the right rear electromagnetic proportional reversing valve 24 is reversed to the left position, the oil enters the steering plunger cylinder through the four electromagnetic proportional reversing valves so as to enter the four wheel steering mechanisms, and then returns to the oil tank 28 through the electromagnetic switch valve 26 and the one-way valve 25, and the robot realizes the tilting function shown in (d) of fig. 3;

5) If the received movement steering instruction is a traversing mode instruction, the permanent magnet motor 1 drives the closed axial plunger pump 2, the left front electromagnetic directional valve 8 is switched to the right position, oil enters the left front wheel motor 4 from the port P1 through the left front electromagnetic directional valve 8, flows out of the left front wheel motor 4 from the port B, returns to the closed axial plunger pump 2 through the port T1, the right rear electromagnetic directional valve 9 is switched to the right position, oil enters the right rear wheel motor 5 from the port A through the right rear electromagnetic directional valve 9 from the port P2, flows out of the right rear wheel motor 5 from the port B, and returns to the closed axial plunger pump 2 through the port T2; the right front electromagnetic directional valve 10 is switched to the right position, oil flows through the electromagnetic directional valve 10 from the port P3, enters the right front wheel motor 6 from the port A, flows out of the right front wheel motor 6 from the port B, returns to the closed axial plunger pump 2 from the port T3, the left rear electromagnetic directional valve 11 is switched to the right position, oil flows into the left rear wheel motor 7 from the port A through the left rear electromagnetic directional valve 11 from the port P4, flows out of the left rear wheel motor 7 from the port B, and returns to the closed axial plunger pump 2 from the port T4; meanwhile, the permanent magnet motor 1 drives the gear pump 13, oil flows through the P port to enter the steering mechanism valve group 12, wherein the left front electromagnetic proportional reversing valve 15 is reversed to the left position, the right front electromagnetic proportional reversing valve 18 is reversed to the left position, the left rear electromagnetic proportional reversing valve 21 is reversed to the right position, the right rear electromagnetic proportional reversing valve 24 is reversed to the left position, and the oil enters the steering plunger cylinder through the four electromagnetic proportional reversing valves so as to enter the four wheel steering mechanisms, and then returns to the oil tank 28 through the electromagnetic switch valve 26 and the one-way valve 25, so that the robot achieves a traversing function.

The hydraulic system of the electrohydraulic four-wheel drive transportation robot comprises a permanent magnet motor, a closed axial plunger pump, a gear pump, a plurality of wheel motors, a motor valve group, a plurality of wheel steering mechanisms, a steering plunger cylinder group, a steering mechanism valve group, an oil tank and a control element; the permanent magnet motor is connected with a closed axial plunger pump, and the closed axial plunger pump and a plurality of wheel motors form a closed loop through a motor valve group; the permanent magnet motor is connected with a gear pump, and the gear pump is connected with a plurality of wheel edge steering mechanisms through a steering mechanism valve group and a steering plunger cylinder group; the oil tank is used for storing oil; the permanent magnet motor is used for driving the closed axial plunger pump and the gear pump; the closed axial plunger pump is used for sending oil in the oil tank to the motor valve group; the gear pump is used for conveying oil in the oil tank to the steering mechanism valve group; the control element is used for adjusting the motor valve group and the steering mechanism valve group based on the moving steering instruction; the motor valve group is used for sending oil to the corresponding wheel side motors based on the control of the control element so as to drive the wheel side motors, and therefore the robot moves according to the movement steering instruction; the steering mechanism valve group is used for sending oil to the corresponding steering plunger cylinder group based on the control of the control element so as to drive the wheel side steering mechanism, and therefore the robot steers according to the moving steering instruction. Under the condition, the closed axial plunger pump forms a closed loop with a plurality of wheel motors through the motor valve group, and the size of the oil tank can be reduced by adopting a closed loop mode, so that the hydraulic system can meet the frame requirement more. In addition, the motor valve group is utilized to respectively control the plurality of wheel side motors, and the steering mechanism valve group is utilized to respectively control the plurality of wheel side steering mechanisms, so that the turning radius can be reduced, and the steering sensitivity is improved.

In addition, the hydraulic system and the working method thereof utilize various elements such as a permanent magnet motor, a closed axial plunger pump, a gear pump, a wheel motor, a motor valve group, a plurality of wheel steering mechanisms, a steering plunger cylinder group, a steering mechanism valve group, an oil tank and the like, and the permanent magnet motor is connected with the closed axial plunger pump and forms a closed loop with the wheel motor to finish rotation; the permanent magnet motor is connected with a gear pump, and the gear pump is connected with each steering plunger cylinder through an electromagnetic proportional reversing valve to respectively control each steering mechanism to finish steering. The traveling and turning functions such as advancing and retreating, left and right steering, in-situ steering, transverse movement and the like of the transportation robot can be realized, the current situation that the existing transportation robot turns inflexibly and has overlarge turning radius is changed, the traveling under complex conditions is met, the turning radius is small, and the traveling and turning device has the characteristics of powerful function, high reliability, convenience in layout, lower cost and the like. The four wheel motors are respectively controlled by four electromagnetic directional valves, so that the functions of adjusting different speed gears and reducing turning radius can be realized. The size of the oil tank is reduced by adopting a closed loop mode, so that the hydraulic system can meet the requirements of the frame. The frame of the transportation robot provided with the hydraulic system is smaller, more flexible, flexible and small, and convenient to install; a closed loop is adopted, four wheel motors are driven by a closed axial plunger pump, and a supplementary oil pump is additionally arranged to update an oil loop; the gear pump drives four steering mechanisms, the turning radius is smaller, the precision is higher, and the gear pump is more suitable for complex terrains.

The following is an embodiment of the method according to the present invention, and for details not disclosed in the embodiment of the method according to the present invention, reference is made to an embodiment of the system according to the present invention. The embodiment of the method provides a working method of an electrohydraulic four-wheel drive transportation robot hydraulic system. The working method of the electrohydraulic four-wheel drive transportation robot hydraulic system adopts the electrohydraulic four-wheel drive transportation robot hydraulic system of the embodiment of the system.

Fig. 4 shows a flow chart of a working method of an electrohydraulic four-wheel drive transportation robot hydraulic system provided by an embodiment of the invention. As shown in fig. 4, the working method of the hydraulic system of the electrohydraulic four-wheel drive transportation robot comprises the following steps:

step S11, controlling the starting of a permanent magnet motor, and driving a closed axial plunger pump and a gear pump by using the permanent magnet motor;

step S12, the control element receives a mobile steering instruction and adjusts a motor valve group and a steering mechanism valve group based on the mobile steering instruction;

step S13, the closed axial plunger pump sends oil in an oil tank to a motor valve group, and the oil is sent to a corresponding wheel side motor through the motor valve group so as to drive the wheel side motor, so that the robot moves according to a movement steering instruction;

and S14, the gear pump sends oil in the oil tank to the steering mechanism valve group, and the oil is sent to the corresponding steering plunger cylinder group through the steering mechanism valve group so as to drive the wheel side steering mechanism, so that the robot steers according to the moving steering instruction.

In the present embodiment, the control element is used to control the start of the permanent magnet motor in step S11.

In the present embodiment, the movement steering instruction in step S12 includes five instructions of a forward mode, a steering mode, a turn-around-in-place mode, a tilting mode, and a traversing mode.

In this embodiment, the specific process of controlling the robot to move and steer according to the movement steering command in steps S12 to S14 may refer to the related description in the above system embodiment, which is not described herein.

It should be noted that the foregoing explanation of the embodiment of the hydraulic system of the electrohydraulic four-wheel drive transportation robot is also applicable to the working method of the hydraulic system of the electrohydraulic four-wheel drive transportation robot in this embodiment, and is not repeated herein.

The foregoing embodiment numbers of the present invention are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.

In the working method of the hydraulic system of the electrohydraulic four-wheel drive transportation robot, the starting of a permanent magnet motor is controlled, and a closed axial plunger pump and a gear pump are driven by the permanent magnet motor; the control element receives a mobile steering command and adjusts the motor valve group and the steering mechanism valve group based on the mobile steering command; the closed axial plunger pump sends oil in the oil tank to the motor valve group, and sends the oil to the corresponding wheel side motor through the motor valve group so as to drive the wheel side motor, so that the robot moves according to a movement steering instruction; the gear pump sends oil in the oil tank to the steering mechanism valve group, and sends the oil to the corresponding steering plunger cylinder group through the steering mechanism valve group so as to drive the wheel side steering mechanism, thereby enabling the robot to steer according to the moving steering instruction. Under the condition, the closed axial plunger pump forms a closed loop with a plurality of wheel motors through the motor valve group, and the size of the oil tank can be reduced by adopting a closed loop mode, so that the hydraulic system can meet the frame requirement more. In addition, the motor valve group is utilized to respectively control the plurality of wheel side motors, and the steering mechanism valve group is utilized to respectively control the plurality of wheel side steering mechanisms, so that the turning radius can be reduced, and the steering sensitivity is improved.

In the accompanying drawings, there is shown a schematic structural diagram in accordance with a disclosed embodiment of the invention. The figures are not drawn to scale, wherein certain details are exaggerated for clarity of presentation and may have been omitted. The shapes of the various regions, layers and their relative sizes, positional relationships shown in the drawings are merely exemplary, may in practice deviate due to manufacturing tolerances or technical limitations, and one skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions as actually required.

It should be appreciated that various forms of the flows shown above may be used to reorder, add, or delete steps. For example, the steps described in the present disclosure may be performed in parallel, sequentially, or in a different order, so long as the desired result of the technical solution disclosed in the present disclosure is achieved, and the present invention is not limited herein.

The above embodiments do not limit the scope of the present invention. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention.

Claims (10)

1. The hydraulic system of the electrohydraulic four-wheel-drive transportation robot is characterized by comprising a permanent magnet motor, a closed axial plunger pump, a gear pump, a plurality of wheel motors, a motor valve group, a plurality of wheel steering mechanisms, a steering plunger cylinder group, a steering mechanism valve group, an oil tank and a control element;

the permanent magnet motor is connected with the closed axial plunger pump, and the closed axial plunger pump and the wheel side motors form a closed loop through the motor valve group; the permanent magnet motor is connected with the gear pump, and the gear pump is connected with the plurality of wheel steering mechanisms through the steering mechanism valve group and the steering plunger cylinder group;

the oil tank is used for storing oil; the permanent magnet motor is used for driving the closed axial plunger pump and the gear pump; the closed axial plunger pump is used for sending oil in the oil tank to the motor valve group; the gear pump is used for sending oil in the oil tank to the steering mechanism valve group; the control element is used for adjusting the motor valve group and the steering mechanism valve group based on a moving steering instruction; the motor valve group is used for sending oil to the corresponding wheel side motors based on the control of the control element so as to drive the wheel side motors, and therefore the robot moves according to the movement steering instruction; the steering mechanism valve group is used for sending oil to the corresponding steering plunger cylinder group based on the control of the control element so as to drive the wheel side steering mechanism, and therefore the robot is steered according to the moving steering instruction.

2. The electro-hydraulic four-wheel-drive transport robot hydraulic system of claim 1, wherein the plurality of wheel-side motors is four wheel-side motors, and the motor valve block includes four electromagnetic directional valves, each electromagnetic directional valve controlling a separate one of the wheel-side motors.

3. The electro-hydraulic four-wheel drive transport robot hydraulic system of claim 2, wherein the closed axial plunger pump includes a supplemental pump for updating oil of the closed circuit.

4. The electro-hydraulic four-wheel-drive transport robot hydraulic system of claim 3, wherein the plurality of wheel-side steering mechanisms is four wheel-side steering mechanisms, the steering mechanism valve block includes four electromagnetic proportional reversing valves, the steering plunger cylinder block includes four steering plunger cylinders, each electromagnetic proportional reversing valve controls a separate one of the steering plunger cylinders, each steering plunger cylinder controls a separate one of the wheel-side steering mechanisms.

5. The electro-hydraulic four-wheel-drive transport robot hydraulic system of claim 4, wherein the steering mechanism valve block further comprises an electromagnetic switch valve and an overflow valve, the hydraulic system further comprises a one-way valve, the wheel-side steering mechanism is connected with the oil tank through the electromagnetic switch valve, the one-way valve and the oil tank, and the overflow valve is connected with the electromagnetic switch valve in parallel.

6. The electro-hydraulic four-wheel drive transport robot hydraulic system of claim 5, further comprising a coarse filter and a fine filter, wherein the oil tank is connected to the closed axial plunger pump via the coarse filter and the fine filter.

7. The electro-hydraulic four-wheel drive transport robot hydraulic system of claim 6, further comprising a plate heat exchanger for exchanging heat generated by the closed circuit during operation to achieve cooling, and an air filter for cleaning oil in the oil circuit.

8. The electro-hydraulic four-wheel drive transport robot hydraulic system of claim 6, further comprising a liquid level thermometer and a liquid level thermometer sensor for real-time detection of tank level and oil temperature.

9. A method of operation based on an electrohydraulic four-wheel drive transportation robot hydraulic system according to any of the claims 1-8, comprising:

controlling the permanent magnet motor to start, and driving the closed axial plunger pump and the gear pump by using the permanent magnet motor;

the control element receives a moving steering instruction and adjusts the motor valve group and the steering mechanism valve group based on the moving steering instruction;

the closed axial plunger pump sends oil in an oil tank to the motor valve group, and sends the oil to the corresponding wheel side motor through the motor valve group so as to drive the wheel side motor, so that the robot moves according to the movement steering instruction;

the gear pump sends oil in the oil tank to the steering mechanism valve group, and sends the oil to the corresponding steering plunger cylinder group through the steering mechanism valve group so as to drive the wheel-side steering mechanism, thereby enabling the robot to steer according to the moving steering instruction.

10. The method of claim 9, wherein the movement steering commands include five commands, a forward mode, a steering mode, a turn-around-in-place mode, a tilt mode, and a traverse mode.