An intelligent test system for stepless speed regulation hydraulic drive chassis

Abstract

An intelligent test system for a stepless speed regulation hydraulic drive chassis, wherein a closed drive test circuit includes an engine, a transfer case, a variable pump, a closed drive test branch, and electromagnetic reversing valves 1, 3, and 4; a closed oil replenishment circuit includes an oil replenishment pump, an oil replenishment pressure regulating valve, and balance branches 1 and 2; an open drive test circuit includes a proportional overflow valve 1, an open drive motor 1, an open drive motor 2, a magnetic powder brake 2, a tension controller 2, a magnetic powder brake 3, a tension controller 3, and electromagnetic reversing valves 5, 6, 7, 8, and 10; and a cooling circuit includes a cooling pump, an electric clutch, a drive motor, a check valve 3, a cooling overflow valve, a back pressure valve, a cooler, a temperature sensor, an accumulator, and electromagnetic reversing valves 9 and 11. The system can provide a test platform for both a hydraulic open drive circuit and a hydraulic closed drive circuit, and at the same time, it can realize a dynamic load loading process, and can provide reliable technical support for the design of a stepless speed regulation hydraulic drive chassis.

Description

Technical Field

[0001] The invention relates to the technical field of intelligent agricultural machinery, and in particular to an intelligent testing system for a stepless speed regulation hydraulically driven chassis. Background Art

[0002] The document "14th Five-Year Plan for the Development of National Agricultural Mechanization" issued by the Ministry of Agriculture and Rural Affairs points out that it is necessary to promote the integrated application of technologies such as continuously variable transmission and electromechanical-hydraulic integration in agricultural machinery and equipment, and accelerate the innovation and development of large-scale high-end intelligent agricultural machinery and equipment. In recent years, hydraulically driven chassis have gradually emerged. Compared with traditional mechanical chassis, they have the advantages of high power density, flexible layout, easy to achieve stepless speed regulation and automatic control, so they have been widely used in agricultural machinery and engineering machinery. The hydraulically driven chassis can be divided into open drive circuits and closed drive circuits, both of which are widely used in different occasions. The existing system for testing hydraulic chassis has a single function and can usually only provide test operations for open drive circuits or closed drive circuits. At the same time, it does not have the function of dynamic load loading and cannot provide reliable technical support for the design optimization of stepless speed regulation hydraulic drive chassis. Summary of the invention

[0003] In view of the problems existing in the above-mentioned prior art, the present invention provides an intelligent testing system for a stepless speed regulation hydraulic drive chassis, which can provide a testing platform for both the hydraulic open drive circuit and the hydraulic closed drive circuit. At the same time, it can realize a dynamic load loading process and can measure multiple parameters of the open and closed drive chassis during the test process, thereby providing reliable technical support for the design optimization of the stepless speed regulation hydraulic drive chassis.

[0004] In order to achieve the above-mentioned object, the present invention provides a stepless speed regulation hydraulic drive chassis intelligent test system, comprising an oil tank, a closed drive test circuit, a closed oil replenishment circuit, an open drive test circuit, a cooling circuit and a controller;

[0005] The closed drive test circuit includes an engine, a transfer case, a variable pump, a flow sensor 1, an electromagnetic reversing valve 1, a speed sensor 1, a pressure sensor 2, a pressure sensor 1, a closed drive test branch, an electromagnetic reversing valve 3 and an electromagnetic reversing valve 4;

[0006] The input end of the transfer case is connected to the output shaft of the engine;

[0007] The variable displacement pump is connected to a variable displacement piston, and its transmission shaft is coaxially connected to the first output shaft of the transfer case;

[0008] The A port of the electromagnetic reversing valve 1 is connected to the P port of the variable pump through the flow sensor 1;

[0009] The speed sensor 1 is connected to the transmission shaft of the variable pump and is used to collect the speed signal 1 of the variable pump in real time;

[0010] The second pressure sensor is connected to the S port of the variable displacement pump;

[0011] The pressure sensor 1 is connected to the port A of the electromagnetic reversing valve 1;

[0012] The closed drive test branch has at least two circuits, and the closed drive test branch includes a test oil circuit 1, a test oil circuit 2, a closed drive motor, an electromagnetic reversing valve 2, a flow sensor 2, a speed sensor 2, a magnetic powder brake 1 and a tension controller 1; the first end of the test oil circuit 1 is connected to the B port of the electromagnetic reversing valve 1; the A port of the drive motor is connected to the A port of the electromagnetic reversing valve 2 and then connected to the second end of the test oil circuit 1, the B port of the drive motor is connected to the B port of the electromagnetic reversing valve 2 and then connected to the first end of the test oil circuit 2, and the flow sensor 2 is connected in series to the test oil circuit 2; the speed sensor 2 is connected to the transmission shaft of the closed drive motor; the magnetic powder brake 1 is arranged on the outside of the transmission shaft of the closed drive motor, and is used to realize the braking operation of the closed drive motor after receiving the control signal; the tension controller 1 is connected to the magnetic powder brake 1, and is used to output a control signal to the magnetic powder brake 1;

[0013] The A port of the electromagnetic reversing valve 3 is connected to the second end of the test oil circuit 2, and the B port thereof is connected to the S port of the variable pump;

[0014] The B port of the electromagnetic reversing valve 4 is connected to the S port of the variable pump, and the A port thereof is connected to the oil tank;

[0015] The closed oil replenishment circuit includes an oil replenishment pump, a third speed sensor, a third flow sensor, an oil replenishment pressure control valve, a third pressure sensor, a first balancing branch and a second balancing branch;

[0016] The oil replenishment pump is coaxially connected to the second output shaft of the transfer case, and its oil suction port is connected to the oil tank through an oil suction pipeline 1;

[0017] The speed sensor 3 is connected to the transmission shaft of the oil replenishment pump and is used to collect the speed signal 2 of the oil replenishment pump in real time;

[0018] The oil inlet of the oil replenishment pressure regulating valve is connected to the oil discharge port of the oil replenishment pump through a flow sensor 3, and the oil outlet and leakage port thereof are both connected to the oil tank;

[0019] The pressure sensor 3 is connected to the oil inlet of the oil replenishment pressure regulating valve;

[0020] The balancing branch 1 includes a one-way valve 1 and a high-pressure relief valve 1, the oil outlet of the one-way valve 1 is connected to the oil inlet of the high-pressure relief valve 1 and then connected to the B port of the electromagnetic reversing valve 3, the oil inlet of the one-way valve 1 is connected to the oil outlet of the high-pressure relief valve 1 and then connected to the oil inlet of the oil replenishment pressure control valve;

[0021] The second balancing branch includes a second one-way valve and a second high-pressure relief valve. The oil outlet of the second one-way valve is connected to the oil inlet of the second high-pressure relief valve and then connected to the P port of the variable pump. The oil inlet of the second one-way valve is connected to the oil outlet of the second high-pressure relief valve and then connected to the oil inlet of the oil replenishment pressure control valve.

[0022] The open drive test circuit includes an electromagnetic reversing valve 5, an electromagnetic reversing valve 6, a proportional relief valve 1, a pressure sensor 4, an electromagnetic reversing valve 10, an open drive motor 1, a flow sensor 4, an open drive motor 2, a pressure sensor 5, a pressure sensor 6, a pressure sensor 7, a speed sensor 4, a magnetic powder brake 2, a tension controller 2, a speed sensor 5, a magnetic powder brake 3, a tension controller 3, an electromagnetic reversing valve 7 and an electromagnetic reversing valve 8;

[0023] The port A of the electromagnetic reversing valve 5 is connected to the port A of the electromagnetic reversing valve 1;

[0024] The port B of the electromagnetic reversing valve 6 is connected to the port A of the electromagnetic reversing valve 5;

[0025] The oil inlet of the proportional relief valve 1 is connected to the port A of the electromagnetic reversing valve 6, and the oil outlet and leakage port thereof are both connected to the oil tank;

[0026] The pressure sensor 4 is connected to the port B of the electromagnetic reversing valve 5;

[0027] The P port of the electromagnetic reversing valve 10 is connected to the B port of the electromagnetic reversing valve 5, and its T port is connected to the oil tank;

[0028] The B port of the open drive motor 1 is connected to the A port of the electromagnetic reversing valve 10, the B port of the open drive motor 2 is connected to the A port of the open drive motor 1, and the A port thereof is connected to the B port of the electromagnetic reversing valve 10 through the flow sensor 4;

[0029] The pressure sensor 5 is connected to the B port of the open drive motor 1; the pressure sensor 6 is connected to the B port of the open drive motor 2; the pressure sensor 7 is connected to the A port of the electromagnetic reversing valve 8;

[0030] The speed sensor 4 is connected to the transmission shaft of the open drive motor 1; the magnetic powder brake 2 is arranged on the outside of the transmission shaft of the open drive motor 1, and is used to realize the braking operation of the open drive motor 1 after receiving the control signal; the tension controller 2 is connected to the magnetic powder brake 2, and is used to output the control signal to the magnetic powder brake 2;

[0031] The speed sensor 5 is connected to the transmission shaft of the open drive motor 2; the magnetic powder brake 3 is arranged on the outside of the transmission shaft of the open drive motor 2, and is used to realize the braking operation of the open drive motor 2 after receiving the control signal; the tension controller 3 is connected to the magnetic powder brake 3, and is used to output the control signal to the magnetic powder brake 3;

[0032] The B port of the electromagnetic reversing valve 7 is connected to the A port of the electromagnetic reversing valve 10, and its A port is connected to the A port of the open drive motor 1; the A port of the electromagnetic reversing valve 8 is connected to the B port of the electromagnetic reversing valve 10, and its B port is connected to the B port of the open drive motor 2;

[0033] The cooling circuit includes a cooling pump, an electric clutch, a drive motor, a check valve three, a cooling overflow valve, a back pressure valve, a cooler, an electromagnetic reversing valve eleven, an accumulator, an electromagnetic reversing valve nine and a temperature sensor;

[0034] The drive motor is connected via a transmission shaft of an electric clutch;

[0035] The oil inlet of the one-way valve 3 is connected to the oil tank, the oil outlet is connected to the oil inlet of the cooling pump and the P port of the cooling pump, and the oil outlet and the leakage port are both connected to the oil tank;

[0036] The P port of the back pressure valve is connected;

[0037] The oil inlet of the cooler is connected to the back pressure valve;

[0038] The port A of the electromagnetic reversing valve 11 is connected to the oil outlet of the one-way valve 3;

[0039] The B port of the electromagnetic reversing valve 9 is connected to the A port of the electromagnetic reversing valve 3, and the A port thereof is respectively connected to the working oil port of the accumulator and the B port of the electromagnetic reversing valve 11;

[0040] The temperature sensor is installed inside the oil tank and is used to collect the temperature signal of the hydraulic oil in the oil tank in real time;

[0041] The controller is respectively connected with the engine, the driving motor, the electric clutch, the tension controller 1, the tension controller 2, the tension controller 3, the electromagnetic reversing valve 1, the electromagnetic reversing valve 2, the electromagnetic reversing valve 3, the electromagnetic reversing valve 4, the electromagnetic reversing valve 5, the electromagnetic reversing valve 6, the electromagnetic reversing valve 7, the electromagnetic reversing valve 8, the electromagnetic reversing valve 9, the electromagnetic reversing valve 10, the electromagnetic reversing valve 11, the flow sensor 1, the flow sensor 2, the flow sensor 3, the flow sensor 4, the speed sensor 1, the speed sensor 2, the speed sensor 3, the speed sensor 4, the speed sensor 5, the pressure sensor 1, the pressure sensor 2, the pressure sensor 3, the pressure sensor 4, the pressure sensor 5, the pressure sensor 6 and the pressure sensor 7.

[0042] Furthermore, in order to avoid overcharging of the accumulator, the cooling circuit also includes a proportional overflow valve 2, the oil inlet of the proportional overflow valve 2 is connected to the A port of the electromagnetic reversing valve 9, and the oil outlet and leakage port of the proportional overflow valve 2 are both connected to the oil tank.

[0043] Furthermore, in order to prevent impurities from entering the system and causing damage to the hydraulic components, the closed drive test circuit also includes a filter, which is connected in series at the B port of the electromagnetic reversing valve four.

[0044] Furthermore, in order to facilitate real-time perception of the energy storage status of the accumulator, the cooling circuit also includes an energy storage pressure sensor, and the energy storage pressure sensor is connected to the accumulator.

[0045] As a preference, the number of the closed drive test branches is four.

[0046] As a preference, the closed drive motor is a variable motor.

[0047] As a preferred embodiment, the solenoid reversing valve 1, solenoid reversing valve 2, solenoid reversing valve 3, solenoid reversing valve 4, solenoid reversing valve 5, solenoid reversing valve 6, solenoid reversing valve 7, solenoid reversing valve 8 and solenoid reversing valve 9 are all two-position two-way solenoid reversing valves. For the solenoid reversing valve 1, solenoid reversing valve 3, solenoid reversing valve 4, solenoid reversing valve 5 and solenoid reversing valve 6, they work in the left position when energized, and the oil circuit between their A port and their B port is connected; they work in the right position when power is lost, and their A port and their B port are cut off. For the solenoid reversing valve 2, solenoid reversing valve 7, solenoid reversing valve 8, solenoid reversing valve 9 and solenoid reversing valve 11, they work in the upper position when energized, and the oil circuit between their A port and their B port is connected; they work in the lower position when power is lost, and their A port and their B port are cut off.

[0048] As a preferred embodiment, the solenoid reversing valve ten is a three-position four-way solenoid reversing valve. When it is energized and working in the left position, the oil circuit between its P port and A port is connected, and the oil circuit between its T port and B port is connected. When it is de-energized and working in the middle position, its P port is cut off, its T port is cut off, its A port is cut off, and its B port is cut off. When it is energized and working in the right position, the oil circuit between its P port and B port is connected, and the oil circuit between its T port and A port is connected.

[0049] As a preference, the controller is a PLC controller.

[0050] In the present invention, by setting the speed sensor 1, it is convenient to collect the speed signal of the variable pump in real time, and then it is convenient to obtain the actual speed data of the variable pump. By setting the pressure sensor 1, it is convenient to collect the pressure signal of the variable pump P port in real time, and then it is convenient to obtain the output pressure data of the variable. A flow sensor 1 is set between the variable pump and the electromagnetic reversing valve 1, which is convenient to collect the flow signal of the oil output by the variable pump in real time, and then it is convenient to obtain the output flow data of the variable pump. Therefore, the volumetric efficiency of the variable pump can be obtained by using the output flow and theoretical flow of the variable pump, and at the same time, the output power of the variable pump can be calculated by using the output flow and output pressure of the variable pump. Making the closed drive test branch at least two ways can meet the test requirements of the two-wheel drive chassis. In each closed drive test branch, the closed drive motor is connected in parallel with the electromagnetic reversing valve 2, and the closed drive motor can be conveniently connected to or disconnected from the test branch by controlling the electromagnetic reversing valve 2, which greatly improves the convenience of the test. A flow sensor 2 is set in each closed drive test branch, which can facilitate real-time acquisition of the output flow signal of the closed drive motor connected to the system, and then facilitate the acquisition of the output flow data of the corresponding closed drive motor. The output flow data of all closed drive test branches are summed and then compared with the output flow data of the variable pump obtained by the flow sensor 1, so that the total volumetric efficiency of all closed drive motors connected to the test branch can be obtained. In the closed drive test branch, a magnetic powder brake 1 is equipped for the closed drive motor, and at the same time, a tension controller 1 is connected to the magnetic powder brake 1, so that the magnetic powder brake 1 can be used to load torque for the closed drive motor. At the same time, the tension controller 1 can be used to adjust the size of the loaded load torque, so that a dynamic load loading process can be realized. The electromagnetic reversing valve 1 and the electromagnetic reversing valve 3 are connected to the two ends of the closed drive test branch respectively. At the same time, the electromagnetic reversing valve 4 is connected to the S port of the variable pump. It is convenient to isolate the closed drive test branch by disconnecting the electromagnetic reversing valves 1 and 3, and further provide a power oil source for the variable pump by controlling the connection of the electromagnetic reversing valve 4, so as to provide power supply for other test circuits. Through the setting of the flow sensor 3, it is convenient to collect the output flow signal of the oil replenishment pump in real time, and then it is convenient to obtain the output flow data of the oil replenishment pump. Through the setting of the pressure sensor 3, it is convenient to collect the output pressure signal of the oil replenishment pump in real time, and then it is convenient to obtain the output pressure data of the oil replenishment pump, thereby calculating the power of the closed oil replenishment circuit, and by summing the output power of the variable pump and the oil replenishment pump, the total power of the closed drive test circuit can be obtained. By using a variable pump as the power source of the closed drive test loop, when the total power of the closed drive test loop exceeds the maximum power of the engine, the displacement of the variable pump can be automatically reduced, thereby reducing the output power, avoiding the engine stalling due to power overload, and ensuring the reliable progress of the test process.The two balanced branches are composed of a one-way valve and a high-pressure relief valve, and the oil inlets of the one-way valves in the two balanced branches are connected to the oil discharge port of the oil replenishment pump, and the oil outlets of the one-way valves in the two balanced branches are respectively connected to the P port of the variable pump and the A port of the electromagnetic reversing valve three, so that the leaked oil can be replenished in time when the pressure on either side of the closed drive test branch is low, thereby effectively filling the oil leakage loss of the closed drive test branch. Since a high-pressure relief valve is provided in each balanced branch, it can avoid the occurrence of excessive high pressure on either side, thereby effectively ensuring the test effect of the closed drive motor and at the same time ensuring the accurate acquisition of the performance parameters of the closed drive chassis. The proportional relief valve 1 is used as a safety valve for the open drive test circuit to ensure that the pressure of the open drive test circuit will never exceed the set pressure value. The A port of the electromagnetic reversing valve 5 is connected to the A port of the electromagnetic reversing valve 1, so that the variable pump can be used as the power source of the open drive test circuit. An electromagnetic reversing valve 6 is arranged between the electromagnetic reversing valve 5 and the proportional relief valve 1, so that the proportional relief valve 1 can be connected to or disconnected from the open drive test circuit according to the demand. An electromagnetic reversing valve 10 is arranged between the electromagnetic reversing valve 5 and the open drive motor, so that the electromagnetic reversing valve 10 can be used to change the rotation direction of the open drive motor. Through the arrangement of the electromagnetic reversing valve 7 and the electromagnetic reversing valve 8, it is convenient to control the open drive motors 1 and 2 to be connected to or disconnected from the open drive test circuit through on-off control, thereby improving the flexibility of the test process. A pressure sensor 7, a flow sensor 4, an open drive motor 2, a pressure sensor 6, an open drive motor 1 and a pressure sensor 5 are arranged in sequence in the circuit between the A port and the B port of the electromagnetic reversing valve 10, so that when the electromagnetic reversing valve 10 is connected in the left position, the working pressure of the open drive motor 2 can be measured by the pressure sensor 6, and the oil inlet pressure of the open drive motor 1 can be measured by the pressure sensor 5. The working pressure of the open drive motor 1 can be obtained by subtracting the working pressure measured by the pressure sensor 6 from the oil inlet pressure measured by the pressure sensor 5. In addition, when the electromagnetic reversing valve is connected to the right position, the working pressure of the open drive motor 1 is measured by the pressure sensor 6, and the oil inlet pressure of the open drive motor 2 is measured by the pressure sensor 7. The working pressure of the open drive motor 2 can be obtained by subtracting the working pressure measured by the pressure sensor 6 from the oil inlet pressure measured by the pressure sensor 7. When the open drive test circuit is working, the volumetric efficiency of the variable pump can be obtained by using the ratio of the output flow rate of the variable pump to the theoretical flow rate, and the output power of the variable pump can be calculated by using the output flow rate and output pressure of the variable pump. When the electromagnetic reversing valve is connected to the left position, the flow data flowing through the open drive motor can be obtained by the flow sensor 4, and the flow data obtained by the flow sensor can be compared with the flow data obtained by the flow sensor 1 to obtain the volumetric efficiency of the open drive test circuit.At the same time, the total power of all open drive motors in the open drive test circuit can be calculated by the working pressure measured by the pressure sensor 5 and the flow data measured by the flow sensor 4. The total efficiency of the open drive circuit can be further calculated by the total power of the open drive motor and the output power of the variable pump. In the open drive test circuit, the open drive motor 1 is equipped with a magnetic powder brake 2, and the tension controller 2 is connected to the magnetic powder brake 2. The open drive motor 2 is equipped with a magnetic powder brake 3, and the tension controller 3 is connected to the magnetic powder brake 3. The magnetic powder brakes 2 and 3 can be used to load torque for the closed drive motors 1 and 2. At the same time, the tension controllers 2 and 3 can be used to adjust the size of the load torque, so that a dynamic load loading process can be realized. By setting the temperature sensor, the temperature of the oil in the oil tank can be easily sensed in real time. Furthermore, by setting the cooling circuit, the hydraulic oil can be automatically cooled when the hydraulic oil temperature exceeds the set value. By setting an electromagnetic reversing valve nine between the accumulator and the closed drive test circuit, the accumulator can be connected to or disconnected from the closed drive test circuit by using the electromagnetic reversing valve nine, and the energy in the closed drive test circuit can be recovered and stored in the connected state. By setting an electromagnetic reversing valve eleven between the S port of the cooling pump and the accumulator, the energy in the accumulator can be reused through the on-off control of the electromagnetic reversing valve eleven, so that the energy in the accumulator can be used as the power source of the cooling pump. By setting the one-way valve three, it can be ensured that all the oil in the accumulator is used to drive the cooling pump, ensuring the efficient utilization of energy. By setting a back pressure valve between the cooling pump and the cooler, cavitation can be effectively prevented.

[0051] The system can provide a test platform for both hydraulic open drive circuits and hydraulic closed drive circuits. At the same time, it can realize a dynamic load loading process and measure multiple parameters of the open and closed drive chassis during the test, providing reliable technical support for the design optimization of the stepless speed regulation hydraulic drive chassis. In addition, the system has good energy-saving and environmental protection properties. It can use the inertia in the closed drive test circuit to charge the accumulator. At the same time, it can use the stored energy to drive the cooling circuit for cooling operations, ensuring the stability and reliability of the test system. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is the hydraulic principle diagram of the present invention.

[0053] In the figure: 1, engine, 2, transfer case, 3, fuel tank, 4, variable pump, 5, electromagnetic reversing valve 1, 6, flow sensor 1, 7, speed sensor 1, 8, pressure sensor 1, 9, closed drive test branch, 10, closed drive motor, 11, electromagnetic reversing valve 2, 12, test oil circuit 1, 13, test oil circuit 2, 14, flow sensor 2, 15, speed sensor 2, 16, magnetic powder brake 1, 17, tension controller 1, 18, electromagnetic reversing valve 3, 19, electromagnetic reversing valve 4, 20, pressure sensor 2, 21, balancing branch, 22, balancing branch, 23, one-way valve 1, 24, high-pressure relief valve 1, 25, oil replenishment pump, 26, speed sensor 3, 27, oil replenishment pressure control valve, 28, flow sensor 3, 29, pressure sensor 3, 30, electromagnetic reversing valve 5, 31, electromagnetic reversing valve 6, 32, proportional relief valve 1, 33 , pressure sensor four, 34, electromagnetic reversing valve ten, 35, electromagnetic reversing valve seven, 36, open drive motor one, 37, pressure sensor five, 38, speed sensor four, 39, magnetic powder brake two, 40, tension controller two, 41, electromagnetic reversing valve eight, 42, open drive motor two, 43, flow sensor four, 44, pressure sensor six, 45, speed sensor five, 46, magnetic powder brake three, 47, tension controller three, 48, drive motor, 49, electric clutch, 50, cooling pump, 51, accumulator, 52, cooling overflow valve, 53, back pressure valve, 54, cooler, 55, variable piston, 56, electromagnetic reversing valve nine, 60, one-way valve three, 61, proportional overflow valve two, 62, filter, 63, balancing branch two, 64, one-way valve two, 65, high-pressure overflow valve two, 66, pressure sensor seven, 67, electromagnetic reversing valve eleven. DETAILED DESCRIPTION

[0054] The present invention will be further described below in conjunction with the accompanying drawings.

[0055] like Figure 1 As shown, the present invention provides a stepless speed regulation hydraulic drive chassis intelligent test system, including an oil tank 3, a closed drive test circuit, a closed oil replenishment circuit, an open drive test circuit, a cooling circuit and a controller;

[0056] The closed drive test circuit includes an engine 1, a transfer case 2, a variable pump 4, a flow sensor 1 6, an electromagnetic reversing valve 1 5, a speed sensor 1 7, a pressure sensor 2 20, a pressure sensor 1 8, a closed drive test branch 9, an electromagnetic reversing valve 3 18 and an electromagnetic reversing valve 4 19;

[0057] The input end of the transfer case 2 is connected to the output shaft of the engine 1;

[0058] The variable displacement pump 4 is connected to a variable displacement piston 55, and its transmission shaft is coaxially connected to the first output shaft of the transfer case 2;

[0059] The A port of the electromagnetic reversing valve 5 is connected to the P port of the variable pump 4 through a flow sensor 6;

[0060] The speed sensor 1 7 is connected to the transmission shaft of the variable pump 4 and is used to collect the speed signal 1 of the variable pump 4 in real time;

[0061] The pressure sensor 20 is connected to the S port of the variable displacement pump 4;

[0062] The pressure sensor 8 is connected to the port A of the electromagnetic reversing valve 5;

[0063] The closed drive test branch 9 is at least two-way, and the closed drive test branch 9 includes a test oil circuit 12, a test oil circuit 2 13, a closed drive motor 10, an electromagnetic reversing valve 2 11, a flow sensor 2 14, a speed sensor 2 15, a magnetic powder brake 16 and a tension controller 17; the first end of the test oil circuit 12 is connected to the B port of the electromagnetic reversing valve 15; the A port of the drive motor 10 is connected to the A port of the electromagnetic reversing valve 2 11 and then connected to the second end of the test oil circuit 12, the B port of the drive motor 10 is connected to the B port of the electromagnetic reversing valve 2 11 and then connected to the first end of the test oil circuit 2 13, the flow sensor 2 14 is connected in series to the test oil circuit 2 13; the speed sensor 2 15 is connected to the transmission shaft of the closed drive motor 10; the magnetic powder brake 16 is arranged on the outer side of the transmission shaft of the closed drive motor 10, and is used to realize the braking operation of the closed drive motor 10 after receiving the control signal; The tension controller 17 is connected to the magnetic powder brake 16 and is used to output a control signal to the magnetic powder brake 16;

[0064] The A port of the electromagnetic reversing valve 3 18 is connected to the second end of the test oil circuit 2 13 , and the B port thereof is connected to the S port of the variable pump 4 ;

[0065] The B port of the electromagnetic reversing valve 19 is connected to the S port of the variable pump 4, and the A port thereof is connected to the oil tank 3;

[0066] The closed oil replenishment circuit includes an oil replenishment pump 25, a speed sensor 3 26, a flow sensor 3 28, an oil replenishment pressure control valve 27, a pressure sensor 3 29, a balancing branch 1 21 and a balancing branch 2 63;

[0067] The oil replenishment pump 25 is coaxially connected to the second output shaft of the transfer case 2, and its oil suction port is connected to the oil tank 3 through an oil suction pipeline 1;

[0068] The speed sensor 3 26 is connected to the transmission shaft of the oil replenishment pump 25 and is used to collect the speed signal 2 of the oil replenishment pump 25 in real time;

[0069] The oil inlet of the oil replenishment pressure regulating valve 27 is connected to the oil discharge port of the oil replenishment pump 25 through the flow sensor 3 28, and its oil outlet and leakage port are both connected to the oil tank 3;

[0070] The pressure sensor 3 29 is connected to the oil inlet of the oil replenishment pressure regulating valve 27;

[0071] The balancing branch 1 21 includes a one-way valve 1 23 and a high-pressure relief valve 1 24. The oil outlet of the one-way valve 1 23 is connected to the oil inlet of the high-pressure relief valve 1 24 and then connected to the B port of the electromagnetic reversing valve 3 18. The oil inlet of the one-way valve 1 23 is connected to the oil outlet of the high-pressure relief valve 1 24 and then connected to the oil inlet of the oil replenishment pressure control valve 27.

[0072] The second balancing branch 63 includes a second one-way valve 64 and a second high-pressure relief valve 65. The oil outlet of the second one-way valve 64 is connected to the oil inlet of the second high-pressure relief valve 65 and then connected to the P port of the variable pump 4. The oil inlet of the second one-way valve 64 is connected to the oil outlet of the second high-pressure relief valve 65 and then connected to the oil inlet of the oil replenishment pressure control valve 27.

[0073] The open drive test circuit includes an electromagnetic reversing valve five 30, an electromagnetic reversing valve six 31, a proportional relief valve one 32, a pressure sensor four 33, an electromagnetic reversing valve ten 34, an open drive motor one 36, a flow sensor four 43, an open drive motor two 42, a pressure sensor five 37, a pressure sensor six 44, a pressure sensor seven 66, a speed sensor four 38, a magnetic powder brake two 39, a tension controller two 40, a speed sensor five 45, a magnetic powder brake three 46, a tension controller three 47, an electromagnetic reversing valve seven 35 and an electromagnetic reversing valve eight 41;

[0074] The port A of the electromagnetic reversing valve 5 30 is connected to the port A of the electromagnetic reversing valve 1 5;

[0075] The port B of the electromagnetic reversing valve 6 31 is connected to the port A of the electromagnetic reversing valve 5 30;

[0076] The oil inlet of the proportional relief valve 1 is connected to the port A of the electromagnetic reversing valve 6 31, and its oil outlet and leakage port are both connected to the oil tank 3;

[0077] The pressure sensor 4 33 is connected to the port B of the electromagnetic reversing valve 5 30;

[0078] The P port of the electromagnetic reversing valve 10 34 is connected to the B port of the electromagnetic reversing valve 5 30, and its T port is connected to the oil tank 3;

[0079] The B port of the open drive motor 1 36 is connected to the A port of the electromagnetic reversing valve 10 34, the B port of the open drive motor 2 42 is connected to the A port of the open drive motor 1 36, and its A port is connected to the B port of the electromagnetic reversing valve 10 34 through the flow sensor 4 43;

[0080] The pressure sensor 5 37 is connected to the B port of the open drive motor 1 36; the pressure sensor 6 44 is connected to the B port of the open drive motor 2 42; the pressure sensor 7 66 is connected to the A port of the electromagnetic reversing valve 8 41;

[0081] The speed sensor 4 38 is connected to the transmission shaft of the open drive motor 1 36; the magnetic powder brake 2 39 is arranged on the outside of the transmission shaft of the open drive motor 1 36, and is used to realize the braking operation of the open drive motor 1 36 after receiving the control signal; the tension controller 2 40 is connected to the magnetic powder brake 2 39, and is used to output the control signal to the magnetic powder brake 2 39;

[0082] The speed sensor 5 45 is connected to the transmission shaft of the open drive motor 2 42; the magnetic powder brake 3 46 is arranged on the outside of the transmission shaft of the open drive motor 2 42, and is used to realize the braking operation of the open drive motor 2 42 after receiving the control signal; the tension controller 3 47 is connected to the magnetic powder brake 3 46, and is used to output the control signal to the magnetic powder brake 3 46;

[0083] The B port of the electromagnetic reversing valve 7 35 is connected to the A port of the electromagnetic reversing valve 10 34, and its A port is connected to the A port of the open drive motor 1 36; the A port of the electromagnetic reversing valve 8 41 is connected to the B port of the electromagnetic reversing valve 10 34, and its B port is connected to the B port of the open drive motor 2 42;

[0084] The cooling circuit includes a cooling pump 50, an electric clutch 49, a drive motor 48, a check valve three 60, a cooling overflow valve 52, a back pressure valve 53, a cooler 54, an electromagnetic reversing valve eleven 67, an accumulator 51, an electromagnetic reversing valve nine 56 and a temperature sensor;

[0085] The drive motor 48 is connected to the transmission shaft of the cooling pump 50 through an electric clutch 49;

[0086] The oil inlet of the one-way valve 3 60 is connected to the oil tank 3 , and the oil outlet is connected to the S port of the cooling pump 50 ;

[0087] The oil inlet of the cooling overflow valve 52 is connected to the P port of the cooling pump 50, and the oil outlet and leakage port thereof are both connected to the oil tank 3;

[0088] The oil inlet of the back pressure valve 53 is connected to the P port of the cooling pump 50;

[0089] The oil inlet of the cooler 54 is connected to the oil outlet of the back pressure valve 53, and the oil outlet is connected to the oil tank 3;

[0090] The port A of the electromagnetic reversing valve eleven 67 is connected to the oil outlet of the one-way valve three 60;

[0091] The B port of the electromagnetic reversing valve nine 56 is connected to the A port of the electromagnetic reversing valve three 18, and the A port is respectively connected to the working oil port of the accumulator 51 and the B port of the electromagnetic reversing valve eleven 67;

[0092] The temperature sensor is installed inside the oil tank 3 and is used to collect the temperature signal of the hydraulic oil in the oil tank 3 in real time;

[0093] The controller is respectively connected to the engine 1, the drive motor 48, the electric clutch 49, the tension controller 17, the tension controller 2 40, the tension controller 3 47, the electromagnetic reversing valve 1 5, the electromagnetic reversing valve 2 11, the electromagnetic reversing valve 3 18, the electromagnetic reversing valve 4 19, the electromagnetic reversing valve 5 30, the electromagnetic reversing valve 6 31, the electromagnetic reversing valve 7 35, the electromagnetic reversing valve 8 41, the electromagnetic reversing valve 9 56, the electromagnetic reversing valve 10 34, the electromagnetic reversing valve 11 67, the flow sensor 1 6, the flow sensor 2 14, the flow sensor 3 28, the flow sensor 4 43, the speed sensor 1 7, the speed sensor 2 15, the speed sensor 3 26, the speed sensor 4 38, the speed sensor 5 45, the pressure sensor 1 8, the pressure sensor 2 20, the pressure sensor 3 29, the pressure sensor 4 33, the pressure sensor 5 37, the pressure sensor 6 44 and the pressure sensor 7 66.

[0094] In order to avoid overcharging of the accumulator 51, the cooling circuit also includes a proportional overflow valve 61, the oil inlet of the proportional overflow valve 61 is connected to the A port of the electromagnetic reversing valve 9 56, and the oil outlet and leakage port of the proportional overflow valve 61 are both connected to the oil tank 3.

[0095] In order to prevent impurities from entering the system and causing damage to the hydraulic components, the closed drive test circuit also includes a filter 62, which is connected in series at the B port of the electromagnetic reversing valve 419.

[0096] In order to facilitate real-time perception of the energy storage status of the accumulator 51 , the cooling circuit further includes an energy storage pressure sensor, which is connected to the accumulator 51 .

[0097] As a preferred embodiment, the number of the closed drive test branches 9 is four.

[0098] As a preference, the closed drive motor 10 is a variable motor.

[0099] As a preferred embodiment, the solenoid reversing valve 15, the solenoid reversing valve 211, the solenoid reversing valve 318, the solenoid reversing valve 419, the solenoid reversing valve 530, the solenoid reversing valve 631, the solenoid reversing valve 735, the solenoid reversing valve 841 and the solenoid reversing valve 956 are all two-position two-way solenoid reversing valves. For the solenoid reversing valve 15, the solenoid reversing valve 318, the solenoid reversing valve 419, the solenoid reversing valve 530 and the solenoid reversing valve 631, they work in the left position when energized, and the oil circuit between their A port and their B port is connected. When they lose power, they work in the right position, and their A port is cut off and their B port is cut off. For the solenoid reversing valve 211, the solenoid reversing valve 735, the solenoid reversing valve 841, the solenoid reversing valve 956 and the solenoid reversing valve 1167, they work in the upper position when energized, and the oil circuit between their A port and their B port is connected. When they lose power, they work in the lower position, and their A port is cut off and their B port is cut off.

[0100] As a preferred embodiment, the solenoid reversing valve 10 34 is a three-position four-way solenoid reversing valve. When it is energized and working in the left position, the oil circuit between its P port and A port is connected, and the oil circuit between its T port and B port is connected. When it is de-energized and working in the middle position, its P port is cut off, its T port is cut off, its A port is cut off, and its B port is cut off. When it is energized and working in the right position, the oil circuit between its P port and B port is connected, and the oil circuit between its T port and A port is connected.

[0101] As a preference, the controller is a PLC controller.

[0102] Working principle:

[0103] 1. Closed drive test circuit:

[0104] The variable pump 4 is a power element in the closed drive test circuit. The variable pump 4 can change its own displacement and oil output direction. When the P port of the variable pump 4 outputs high-pressure oil to the outside, it is forward drive. Most conditions are this working condition. The closed drive motor 10 is an actuator in the closed drive test circuit, and the closed drive motor 10 is a variable motor.

[0105] When performing a closed-loop test operation, the solenoid reversing valve 1 5 and the solenoid reversing valve 3 18 are connected, the solenoid reversing valve 4 19 is disconnected, the solenoid reversing valve 9 56 is disconnected, the solenoid reversing valve 5 30 and the solenoid reversing valve 6 31 are disconnected, and the solenoid reversing valve 2 11 in each closed drive test branch 9 is used to determine whether the corresponding closed drive motor 10 is connected to the loop. For example, when the tested chassis is two-wheel drive, the solenoid reversing valve 2 11 in any two closed drive test branches 9 can be made to work in the lower position, and the solenoid reversing valve 2 11 in the remaining two closed drive test branches 9 can be made to work in the upper position. When the upper position is connected to the system, the closed drive motor 10 is "short-circuited" and does not work.

[0106] The theoretical output flow of the variable pump 4 is the product of its displacement and the actual speed. The displacement is set by the controller, the actual speed is measured by the speed sensor 7, and the actual output flow is measured by the flow sensor 6. The output flow / theoretical flow can obtain the volumetric efficiency of the variable pump 4. The output power of the variable pump 4 can be calculated by the output flow and the output pressure, and the output pressure is measured by the pressure sensor 8. Similarly, the flow of the flow sensor 2 14 corresponds to the flow of the closed drive motor 10, and the sum of the flow of all the closed drive motors 10 in the four-way closed drive test branch 9 is equal to the sum of the flow of the four flow sensors 2 14. The ratio of the sum of the measured flow and the measured flow of the flow sensor 6 is the total volumetric efficiency of the four closed drive motors 10.

[0107] The closed drive motor 10 uses a magnetic powder brake 16 to load the load torque, and the magnitude of the load torque is adjusted by a tension controller 17. The tension controller 17 generally uses a 0-10V voltage analog input type. Assuming that the load range of the magnetic powder brake 16 is 0-A (N·m), it corresponds linearly to the 0-10V voltage.

[0108] The oil replenishment pump 25 is used as the power element of the closed oil replenishment circuit. The flow sensor 3 28 measures the output flow of the oil replenishment system, and the pressure sensor 3 29 measures the pressure of the oil replenishment system, thereby calculating the power of the oil replenishment system. The oil output by the oil replenishment pump 25 pushes the one-way valve 1 23 or the one-way valve 2 64 to replenish oil to the low-pressure side to make up for the oil leakage loss of the closed drive test circuit. The oil replenishment pressure is the back pressure of the closed drive test circuit, and the pressure value can be adjusted by the oil replenishment pressure control valve 27.

[0109] The sum of the output powers of the variable pump 4 and the charge pump 25 is the total power of the closed drive test loop, which must be less than the maximum power of the engine 1 at the rated speed point. When the total power of the closed drive test loop exceeds the maximum power of the engine 1 at the rated speed point, the displacement of the variable pump 4 is automatically reduced to reduce the output power to prevent the engine 1 from stalling.

[0110] 2. Open drive test circuit:

[0111] The variable pump 4 also serves as the power element of the open drive test circuit, and the open drive motor 1 36 and the open drive motor 2 42 serve as the actuators of the open drive test circuit. Preferably, both are variable motors. When the open drive test circuit is working, the electromagnetic reversing valve 1 5 and the electromagnetic reversing valve 3 18 are both disconnected, the electromagnetic reversing valve 4 19 and the electromagnetic reversing valve 5 30 are both connected, the electromagnetic reversing valve 6 31 is connected, and the proportional relief valve 1 32 is the safety valve of the circuit. The variable pump 4 sucks oil from the oil tank 3 through the electromagnetic reversing valve 4 19. The electromagnetic reversing valve 10 34 is used to change the rotation direction of the actuator in the circuit. When the electromagnetic reversing valve 10 34 is connected to the circuit in the left position, it is forward drive at this time, and most conditions are this working condition. The electromagnetic reversing valve 7 35 and the electromagnetic reversing valve 8 41 are used to respectively determine whether the corresponding open drive motor 1 36 and the open drive motor 2 42 are connected to the circuit.

[0112] When the electromagnetic reversing valve 10 34 is connected to the circuit in the left position, the pressure sensor 6 44 is used to measure the working pressure of the open drive motor 2 42, and the pressure sensor 5 37 is used to measure the oil inlet pressure of the open drive motor 1 36. The working pressure of the open drive motor 1 36 is the pressure measured by the pressure sensor 5 37 minus the pressure measured by the pressure sensor 6 44. When the electromagnetic reversing valve 10 34 is connected to the circuit in the right position, the pressure sensor 6 44 is used to measure the working pressure of the open drive motor 1 36, and the pressure sensor 7 66 is used to measure the oil inlet pressure of the open drive motor 2 42. The working pressure of the open drive motor 2 42 is the pressure measured by the pressure sensor 7 66 minus the pressure measured by the pressure sensor 6 44.

[0113] The theoretical output flow of the variable pump 4 is the product of its displacement and the actual speed. The displacement is set by the controller, the actual speed is measured by the speed sensor 7, and the actual output flow is measured by the flow sensor 6. The output flow / theoretical flow can obtain the volumetric efficiency of the variable pump 4. The output power of the variable pump 4 can be calculated by the output flow and the output pressure, and the output pressure is measured by the pressure sensor 8. When the electromagnetic reversing valve 10 34 is connected to the circuit in the left position, the system flow flowing through the open drive motor is measured by the flow sensor 4 43. The volumetric efficiency of the open system is the ratio of the measured data of the flow sensor 4 43 to the measured data of the flow sensor 6. The working pressure of the open system can be measured by the pressure sensor 5 37. The total power of the actuator of the open system can be measured by the data of the pressure sensor 5 37 and the data of the flow sensor 4 43. The total efficiency of the open drive circuit can be calculated by dividing the total power of the actuator by the output power of the variable pump 4.

[0114] The load torque loading of magnetic powder brake 2 39 and magnetic powder brake 3 46 in this loop is the same as that of magnetic powder brake 1 16 in the closed drive test loop.

[0115] The power of the variable pump 4 is the output power of the open drive circuit, which needs to be less than the maximum power of the engine 1 at the rated speed point. When the power of the variable pump 4 exceeds the maximum power of the engine 1 at the rated speed point, the displacement of the variable pump 4 is automatically reduced to reduce the output power to prevent the engine 1 from stalling.

[0116] 3. Cooling circuit:

[0117] During the test, when the temperature of the oil in the oil tank 3 is too high, the oil in the oil tank 3 needs to be cooled. A temperature sensor is installed in the oil tank 3 to monitor the oil temperature signal and provide real-time feedback to the controller.

[0118] During the test of the closed drive test loop, the engine 1 and the magnetic powder brake 16 are turned off at the same time, the electromagnetic reversing valve 9 56 is connected, and the closed drive motor 10 continues to rotate due to inertia, and the accumulator 51 can be charged at this time.

[0119] The energy storage pressure sensor can collect the pressure signal inside the accumulator 51 in real time and feed it back to the controller to realize the perception of the energy storage situation of the accumulator 51. When the cooling circuit is working and the energy storage inside the accumulator 51 is sufficient, the electric clutch 49 is controlled to be disconnected, and the electromagnetic reversing valve 11 67 is controlled to be connected. The energy stored in the accumulator 51 enters the S port of the cooling pump 50 through the electromagnetic reversing valve 11 67, driving the cooling pump 50 to rotate, and then the hydraulic oil in the oil tank 3 is sucked in through the S port, and discharged through the P port, and then flows back to the oil tank 3 through the back pressure valve 53 and the cooler 54, so as to achieve the purpose of cooling the hydraulic oil. The cooling overflow valve 52 is a safety valve for the cooling circuit, and the back pressure valve 53 is used to set the back pressure of the cooling circuit, which is generally set to 0.3-0.5MPa to prevent cavitation. When the cooling circuit is working and the energy storage of the accumulator 51 is insufficient, the electric clutch 49 is connected, the electromagnetic reversing valve 11 67 is disconnected, and the driving motor 48 drives the cooling pump 50 to operate. When the oil temperature is lower than the preset temperature, the cooling circuit stops working.

Claims

1. An intelligent testing system for a stepless speed regulating hydraulically driven chassis, comprising an oil tank (3), characterized in that: It also includes a closed drive test circuit, a closed oil replenishment circuit, an open drive test circuit, a cooling circuit and a controller; The closed drive test circuit comprises an engine (1), a transfer case (2), a variable displacement pump (4), a flow sensor 1 (6), an electromagnetic reversing valve 1 (5), a speed sensor 1 (7), a pressure sensor 2 (20), a pressure sensor 1 (8), a closed drive test branch (9), an electromagnetic reversing valve 3 (18) and an electromagnetic reversing valve 4 (19); The input end of the transfer case (2) is connected to the output shaft of the engine (1); The variable displacement pump (4) is connected to a variable displacement piston (55), and its transmission shaft is coaxially connected to the first output shaft of the transfer case (2); The A port of the electromagnetic reversing valve 1 (5) is connected to the P port of the variable pump (4) through the flow sensor 1 (6); The speed sensor 1 (7) is connected to the transmission shaft of the variable pump (4) and is used to collect a speed signal 1 of the variable pump (4) in real time; The second pressure sensor (20) is connected to the S port of the variable displacement pump (4); The pressure sensor 1 (8) is connected to the port A of the electromagnetic reversing valve 1 (5); The closed drive test branch (9) comprises at least two paths, and the closed drive test branch (9) comprises a test oil circuit 1 (12), a test oil circuit 2 (13), a closed drive motor (10), a solenoid reversing valve 2 (11), a flow sensor 2 (14), a speed sensor 2 (15), a magnetic powder brake 1 (16) and a tension controller 1 (17); a first end of the test oil circuit 1 (12) is connected to a port B of a solenoid reversing valve 1 (5); a port A of the drive motor (10) is connected to a port A of a solenoid reversing valve 2 (11) and then connected to a magnetic powder brake 1 (16). The second end of the test oil circuit 1 (12) is connected, the B port of the drive motor (10) is connected to the B port of the electromagnetic reversing valve 2 (11) and then connected to the first end of the test oil circuit 2 (13), and the flow sensor 2 (14) is connected in series to the test oil circuit 2 (13); the speed sensor 2 (15) is connected to the transmission shaft of the closed drive motor (10); the magnetic powder brake 1 (16) is arranged on the outside of the transmission shaft of the closed drive motor (10) and is used to realize the braking operation of the closed drive motor (10) after receiving the control signal; the tension controller 1 (17) is connected to the magnetic powder brake 1 (16) and is used to output a control signal to the magnetic powder brake 1 (16); The A port of the electromagnetic reversing valve 3 (18) is connected to the second end of the test oil circuit 2 (13), and the B port thereof is connected to the S port of the variable pump (4); The B port of the electromagnetic reversing valve 4 (19) is connected to the S port of the variable pump (4), and the A port thereof is connected to the oil tank (3); The closed oil replenishment circuit comprises an oil replenishment pump (25), a rotation speed sensor three (26), a flow sensor three (28), an oil replenishment pressure control valve (27), a pressure sensor three (29), a balancing branch one (21) and a balancing branch two (63); The oil replenishment pump (25) is coaxially connected to the second output shaft of the transfer case (2), and its oil suction port is connected to the oil tank (3) via an oil suction pipeline 1; The speed sensor 3 (26) is connected to the transmission shaft of the oil replenishment pump (25) and is used to collect the speed signal 2 of the oil replenishment pump (25) in real time; The oil inlet of the oil replenishment pressure regulating valve (27) is connected to the oil discharge port of the oil replenishment pump (25) via a flow sensor 3 (28), and the oil outlet and leakage port thereof are both connected to the oil tank (3); The pressure sensor 3 (29) is connected to the oil inlet of the oil replenishment pressure regulating valve (27); The balancing branch one (21) comprises a one-way valve one (23) and a high-pressure relief valve one (24); the oil outlet of the one-way valve one (23) and the oil inlet of the high-pressure relief valve one (24) are connected to each other and then connected to the B port of the electromagnetic reversing valve three (18); the oil inlet of the one-way valve one (23) and the oil outlet of the high-pressure relief valve one (24) are connected to each other and then connected to the oil inlet of the oil replenishment pressure control valve (27); The second balancing branch (63) comprises a second non-return valve (64) and a second high-pressure relief valve (65); the oil outlet of the second non-return valve (64) and the oil inlet of the second high-pressure relief valve (65) are connected to each other and then connected to the P port of the variable pump (4); the oil inlet of the second non-return valve (64) and the oil outlet of the second high-pressure relief valve (65) are connected to each other and then connected to the oil inlet of the oil replenishment pressure control valve (27); The open drive test circuit comprises an electromagnetic reversing valve five (30), an electromagnetic reversing valve six (31), a proportional relief valve one (32), a pressure sensor four (33), an electromagnetic reversing valve ten (34), an open drive motor one (36), a flow sensor four (43), an open drive motor two (42), a pressure sensor five (37), a pressure sensor six (44), a pressure sensor seven (66), a speed sensor four (38), a magnetic powder brake two (39), a tension controller two (40), a speed sensor five (45), a magnetic powder brake three (46), a tension controller three (47), an electromagnetic reversing valve seven (35) and an electromagnetic reversing valve eight (41); The port A of the electromagnetic reversing valve five (30) is connected to the port A of the electromagnetic reversing valve one (5); The port B of the electromagnetic reversing valve 6 (31) is connected to the port A of the electromagnetic reversing valve 5 (30); The oil inlet of the proportional relief valve 1 is connected to the port A of the electromagnetic reversing valve 6 (31), and the oil outlet and leakage port thereof are both connected to the oil tank (3); The pressure sensor 4 (33) is connected to the port B of the electromagnetic reversing valve 5 (30); The P port of the electromagnetic reversing valve ten (34) is connected to the B port of the electromagnetic reversing valve five (30), and its T port is connected to the oil tank (3); The B port of the open drive motor 1 (36) is connected to the A port of the electromagnetic reversing valve 10 (34), the B port of the open drive motor 2 (42) is connected to the A port of the open drive motor 1 (36), and the A port thereof is connected to the B port of the electromagnetic reversing valve 10 (34) via the flow sensor 4 (43); The pressure sensor five (37) is connected to the B port of the open drive motor one (36); the pressure sensor six (44) is connected to the B port of the open drive motor two (42); the pressure sensor seven (66) is connected to the A port of the electromagnetic reversing valve eight (41); The speed sensor 4 (38) is connected to the transmission shaft of the open drive motor 1 (36); the magnetic powder brake 2 (39) is arranged on the outside of the transmission shaft of the open drive motor 1 (36) and is used to realize the braking operation of the open drive motor 1 (36) after receiving the control signal; the tension controller 2 (40) is connected to the magnetic powder brake 2 (39) and is used to output the control signal to the magnetic powder brake 2 (39); The speed sensor five (45) is connected to the transmission shaft of the open drive motor two (42); the magnetic powder brake three (46) is arranged on the outside of the transmission shaft of the open drive motor two (42) and is used to realize the braking operation of the open drive motor two (42) after receiving the control signal; the tension controller three (47) is connected to the magnetic powder brake three (46) and is used to output the control signal to the magnetic powder brake three (46); The B port of the electromagnetic reversing valve seven (35) is connected to the A port of the electromagnetic reversing valve ten (34), and its A port is connected to the A port of the open drive motor one (36); the A port of the electromagnetic reversing valve eight (41) is connected to the B port of the electromagnetic reversing valve ten (34), and its B port is connected to the B port of the open drive motor two (42); The cooling circuit comprises a cooling pump (50), an electric clutch (49), a drive motor (48), a check valve three (60), a cooling overflow valve (52), a back pressure valve (53), a cooler (54), an electromagnetic reversing valve eleven (67), an accumulator (51), an electromagnetic reversing valve nine (56) and a temperature sensor; The drive motor (48) is connected to the transmission shaft of the cooling pump (50) via an electric clutch (49); The oil inlet of the one-way valve (60) is connected to the oil tank (3), and the oil outlet is connected to the S port of the cooling pump (50); The oil inlet of the cooling overflow valve (52) is connected to the P port of the cooling pump (50), and the oil outlet and leakage port thereof are both connected to the oil tank (3); The oil inlet of the back pressure valve (53) is connected to the P port of the cooling pump (50); The oil inlet of the cooler (54) is connected to the oil outlet of the back pressure valve (53), and the oil outlet is connected to the oil tank (3); The port A of the electromagnetic reversing valve eleven (67) is connected to the oil outlet of the one-way valve three (60); The B port of the electromagnetic reversing valve nine (56) is connected to the A port of the electromagnetic reversing valve three (18), and the A port thereof is respectively connected to the working oil port of the accumulator (51) and the B port of the electromagnetic reversing valve eleven (67); The temperature sensor is installed inside the oil tank (3) and is used to collect the temperature signal of the hydraulic oil in the oil tank (3) in real time; The controller is respectively connected to the engine (1), the drive motor (48), the electric clutch (49), the tension controller 1 (17), the tension controller 2 (40), the tension controller 3 (47), the electromagnetic reversing valve 1 (5), the electromagnetic reversing valve 2 (11), the electromagnetic reversing valve 3 (18), the electromagnetic reversing valve 4 (19), the electromagnetic reversing valve 5 (30), the electromagnetic reversing valve 6 (31), the electromagnetic reversing valve 7 (35), the electromagnetic reversing valve 8 (41), the electromagnetic reversing valve 9 (56), the electromagnetic reversing valve 10 (34), the electromagnetic reversing valve 11 (67), flow sensor 1 (6), flow sensor 2 (14), flow sensor 3 (28), flow sensor 4 (43), speed sensor 1 (7), speed sensor 2 (15), speed sensor 3 (26), speed sensor 4 (38), speed sensor 5 (45), pressure sensor 1 (8), pressure sensor 2 (20), pressure sensor 3 (29), pressure sensor 4 (33), pressure sensor 5 (37), pressure sensor 6 (44) and pressure sensor 7 (66) are connected.

2. According to claim 1, a stepless speed regulation hydraulic drive chassis intelligent testing system is characterized in that: The cooling circuit further comprises a proportional overflow valve 2 (61), the oil inlet of the proportional overflow valve 2 (61) being connected to the port A of the electromagnetic reversing valve 9 (56), and the oil outlet and leakage port of the proportional overflow valve 2 (61) being connected to the oil tank (3).

3. The intelligent testing system for a stepless speed regulating hydraulically driven chassis according to claim 2 is characterized in that: The closed drive test loop further comprises a filter (62), and the filter (62) is connected in series to the B port of the electromagnetic reversing valve four (19).

4. The intelligent testing system for a stepless speed regulating hydraulically driven chassis according to claim 3 is characterized in that: The cooling circuit also includes an energy storage pressure sensor, which is connected to the energy storage pressure sensor (51).

5. The intelligent testing system for stepless speed regulation hydraulic drive chassis according to claim 4 is characterized in that: The number of the closed drive test branches (9) is four.

6. The intelligent testing system for stepless speed regulation hydraulic drive chassis according to claim 5 is characterized in that: The closed drive motor (10) is a variable displacement motor.

7. The intelligent testing system for a stepless speed regulating hydraulically driven chassis according to claim 6 is characterized in that: The electromagnetic reversing valve 1 (5), the electromagnetic reversing valve 2 (11), the electromagnetic reversing valve 3 (18), the electromagnetic reversing valve 4 (19), the electromagnetic reversing valve 5 (30), the electromagnetic reversing valve 6 (31), the electromagnetic reversing valve 7 (35), the electromagnetic reversing valve 8 (41) and the electromagnetic reversing valve 9 (56) are all two-position two-way electromagnetic reversing valves. The reversing valve six (31) works in the left position when it is energized, and the oil path between its A port and its B port is connected. When it is de-energized, it works in the right position, and its A port is closed and its B port is closed. As for the electromagnetic reversing valve two (11), the electromagnetic reversing valve seven (35), the electromagnetic reversing valve eight (41), the electromagnetic reversing valve nine (56) and the electromagnetic reversing valve eleven (67), when they are energized, they work in the upper position, and the oil path between their A port and their B port is connected. When they are de-energized, they work in the lower position, and their A port is closed and their B port is closed.

8. The intelligent testing system for stepless speed regulation hydraulic drive chassis according to claim 7 is characterized in that: The electromagnetic reversing valve ten (34) is a three-position four-way electromagnetic reversing valve. When it is energized and working in the left position, the oil circuit between its P port and A port is connected, and the oil circuit between its T port and B port is connected. When it is de-energized and working in the middle position, its P port is cut off, its T port is cut off, its A port is cut off, and its B port is cut off. When it is energized and working in the right position, the oil circuit between its P port and B port is connected, and the oil circuit between its T port and A port is connected.

9. The intelligent testing system for stepless speed regulation hydraulic drive chassis according to claim 8 is characterized in that: The controller is a PLC controller.

Images