A duplex pump hydraulic loading test system

Abstract

The utility model relates to a kind of duplex pump hydraulic loading test system in agricultural machinery testing technical field, including hydraulic oil tank, three-position four-way reversing valve and duplex hydraulic pump, the import of duplex hydraulic pump is communicated with hydraulic oil tank by total filter corresponding, two exports of duplex hydraulic pump are communicated in hydraulic oil tank by first branch and second branch respectively;First pressure gauge, first flowmeter and first back pressure valve are sequentially connected in series on first branch, and first back pressure valve is connected with first overflow valve in parallel;Second pressure gauge, second flowmeter, the P port and A port of three-position four-way reversing valve and second back pressure valve are sequentially connected in series on second branch, the T port and B port of three-position four-way reversing valve are connected hydraulic oil tank and external implement lifting oil circuit respectively, and second overflow valve is connected in parallel in the second branch section from the P port of three-position four-way reversing valve to the export of second back pressure valve;The system can further realize the collaborative loading and comprehensive performance verification of engine train system and hydraulic pump system under real working condition.

Description

Technical Field

[0001] This utility model relates to the field of agricultural machinery testing technology, and in particular to a dual-pump hydraulic loading test system. Background Technology

[0002] With the widespread application of "electronic control + hydraulic" technology in agricultural machinery, systems such as power reversing, power shifting, and continuously variable transmission place higher demands on the performance and reliability of hydraulic pumps. As the core power execution unit of a tractor, the hydraulic system directly determines the tractor's operating efficiency, handling performance, and multi-functional adaptability, and is crucial for the tractor to achieve modern and intelligent operation.

[0003] Currently, the performance and durability verification of hydraulic pumps mostly adopts vehicle-mounted testing. However, although vehicle-mounted testing is closer to actual use, it has a long test cycle, high cost, and makes it difficult to decouple the hydraulic pump and engine wheel system for analysis and controllable repeatability verification. Especially under extreme conditions such as high load and multiple working condition switching, it lacks the ability to identify problems with the structural integrity, sealing performance and durability of the hydraulic pump.

[0004] Therefore, how to effectively integrate hydraulic pumps at the engine test bench level, simulate their working state under various actual working conditions of tractors, and simultaneously verify the strength of the engine wheel system, the structural integrity of the hydraulic pump, its working performance and durability, and quantitatively evaluate the impact of the hydraulic pump on engine performance parameters, has become an urgent technical problem to be solved in the current research and development of agricultural power systems. Utility Model Content

[0005] In order to overcome the shortcomings in the background technology and solve the existing technical problems, this utility model discloses a dual-pump hydraulic loading test system, which can further realize the coordinated loading and comprehensive performance verification of the engine wheel system and hydraulic pump system under real working conditions.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A dual-pump hydraulic loading test system includes a hydraulic oil tank and a three-position four-way directional valve, as well as a dual hydraulic pump with a one-inlet and two-outlet structure formed by a first pump body and a second pump body. The inlet of the dual hydraulic pump is connected to the hydraulic oil tank through a main filter, and the two outlets of the dual hydraulic pump are respectively connected to the hydraulic oil tank through a first branch and a second branch corresponding to the first and second pump bodies. A first pressure gauge, a first flow meter, and a first back pressure valve are connected in series on the first branch, and a first relief valve is connected in parallel to the first back pressure valve. A second pressure gauge, a second flow meter, the P port and A port of the three-position four-way directional valve, and a second back pressure valve are connected in series on the second branch. The T port and B port of the three-position four-way directional valve are respectively connected to the hydraulic oil tank and the external agricultural implement lifting oil circuit. A second relief valve is connected in parallel to the second branch section from the P port of the three-position four-way directional valve to the outlet of the second back pressure valve.

[0008] Furthermore, the system also includes a controller, which is connected to the second pump body and the three-position four-way directional valve respectively.

[0009] Furthermore, the hydraulic oil tank is equipped with a heater, a thermometer, and a level gauge.

[0010] Furthermore, the hydraulic oil tank is equipped with a cooler.

[0011] Furthermore, the hydraulic oil tank is connected to a discharge pipeline with a discharge valve.

[0012] Furthermore, the first and second branches are connected to a circuit valve near the hydraulic oil tank.

[0013] Furthermore, a vacuum pressure gauge is connected to the pipeline between the main filter and the inlet of the dual hydraulic pump.

[0014] Furthermore, a first filter and a second filter are connected in series on the first branch and the second branch near the outlet of the dual hydraulic pump, respectively.

[0015] By adopting the technical solution described above, this utility model has the following beneficial effects:

[0016] This utility model discloses a dual-pump hydraulic loading test system. In a static state, the first pump body is activated, and the pressure demand of the first loading unit is achieved by adjusting the first back pressure valve. The first relief valve plays a pressure-regulating role, limiting the maximum working pressure of the system. While the first loading unit is continuously working, the second pump body is intermittently started, and the on / off state of the second pump body is controlled according to a preset cycle. With the help of a three-position four-way directional valve for position switching, intermittent high-pressure loading and implement lifting simulation tests are realized. The system realistically reproduces the integrity, working performance, and durability of the hydraulic pump under different working conditions such as idling, operation, and heavy load on a tractor. Combined with various detection components, parameters such as pressure and flow rate can be comprehensively collected. With the verification of controllability and adjustability and convenient operation, the test data is more in line with actual application scenarios, providing an accurate basis for matching performance evaluation. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the implementation structure of this utility model.

[0018] In the diagram: 1. Hydraulic oil tank; 2. Main filter; 3. Vacuum pressure gauge; 4. Dual hydraulic pump; 4-1. First pump body; 4-2. Second pump body; 5. First filter; 6. First pressure gauge; 7. First flow meter; 8. First back pressure valve; 9. First relief valve; 10. Controller; 11. Second filter; 12. Second pressure gauge; 13. Second flow meter; 14. Three-position four-way directional valve; 15. Second back pressure valve; 16. Second relief valve; 17. Cooler; 18. Heater; 19. Circuit valve; 20. Level gauge; 21. Thermometer; 22. Drain valve. Detailed Implementation

[0019] The technical solution of this utility model will be described below with reference to the accompanying drawings of the embodiments of this utility model. In the description, it should be understood that if there are terms such as "upper", "lower", "front", "rear", "left", "right" indicating the orientation or positional relationship, they are only corresponding to the drawings of this utility model for the convenience of describing this utility model, and do not indicate or imply that the device or element referred to must have a specific orientation.

[0020] Combined with appendix Figure 1The described dual-pump hydraulic loading test system includes a hydraulic oil tank 1, a three-position four-way directional valve 14, and a dual hydraulic pump 4 with a one-inlet, two-outlet structure formed by a first pump body 4-1 and a second pump body 4-2. The three-position four-way directional valve 14, as shown in the attached diagram, is specifically an O-type valve. The inlet of the dual hydraulic pump 4 is connected to the hydraulic oil tank 1 via a main filter 2. The main filter 2 ensures the cleanliness of the oil entering the pump body and protects the internal components. If necessary, a vacuum pressure gauge 3 is connected to the pipeline between the main filter 2 and the inlet of the dual hydraulic pump 4. Pressure gauge 3 is used to monitor the vacuum at the inlet of the dual hydraulic pump 4 to prevent cavitation failure. The two outlets of the dual hydraulic pump 4 are connected to the hydraulic oil tank 1 through the first branch and the second branch corresponding to the first pump body 4-1 and the second pump body 4-2, respectively. The first pump body 4-1 simulates the basic power reversing function of the tractor, and the second pump body 4-2 simulates the lifting and heavy load loading function of agricultural implements. As needed, the first branch and the second branch are connected to the return valve 1 near the hydraulic oil tank 1. The return valve 19 is used to cut off the return oil circuit in the event of system maintenance or emergency to facilitate maintenance.

[0021] The first branch is connected in series with a first pressure gauge 6, a first flow meter 7, and a first back pressure valve 8. The first back pressure valve 8 is connected in parallel with a first relief valve 9. The first back pressure valve 8 is used to increase the pressure of the first branch to 2 MPa. The first relief valve 9 plays a constant pressure protection role, limiting the maximum working pressure of the system and simulating the continuous loading of the tractor reversing action. As needed, the first branch and the second branch near the outlet of the double hydraulic pump 4 are respectively connected in series with a first filter 5 and a second filter 11. These filters are used to filter out impurities in the oil at the outlet of the double hydraulic pump 4 to ensure the reliable operation of downstream components. The second branch is connected in series with a second pressure gauge 12, a second flow meter 13, the P port and A port of a three-position four-way directional valve 14, and a second back pressure valve 15. The T port and B port of the three-position four-way directional valve 14 are connected in series with a second back pressure valve 15. The hydraulic oil tank 1 is not connected to the external implement lifting oil circuit. The second back pressure valve 15 is used to establish high pressure during loading. The three-position four-way directional valve 14 is used to switch the loading oil circuit of the second pump body 4-2 to simulate the lifting and unloading conditions of the implement. As needed, the system also includes a controller 10. The controller 10 is connected to the corresponding signals of the second pump body 4-2 and the three-position four-way directional valve 14. The controller 10 controls the opening and closing of the on / off control valve of the second pump body 4-2 according to a preset cycle and drives the three-position four-way directional valve 14 to realize the intermittent high pressure loading and implement lifting simulation test. The second branch section from the P port of the three-position four-way directional valve 14 to the outlet of the second back pressure valve 15 is connected in parallel with a second relief valve 16. The second relief valve 16 is used to limit the maximum pressure of the second branch, such as 20 MPa, to prevent overload damage.

[0022] As required, the hydraulic oil tank 1 is equipped with a heater 18, a thermometer 21, and a level gauge 20. The heater 18 is used to heat the system oil to meet the requirements of high-temperature testing. The thermometer 21 monitors the oil temperature in real time, and the level gauge 20 observes the oil level. In addition, the hydraulic oil tank 1 is equipped with a cooler 17, which can be set as a tubular heat exchanger and equipped with a circulating water cooling device to stabilize the oil temperature and maintain a constant internal flow and pressure during full-power operation. Furthermore, the hydraulic oil tank 1 is connected to a discharge pipeline with a drain valve 22, which is used to periodically remove contaminants deposited at the bottom of the tank and replace old oil.

[0023] The specific operation of the dual-pump hydraulic loading test system described in this utility model is as follows: First, start the engine to drive the dual hydraulic pump 4 to run; the first pump body 4-1 works continuously, and the pressure of the first branch is stabilized at 2 MPa by adjusting the first back pressure valve 8. The first overflow valve 9 plays the role of constant pressure overflow, simulating the uninterrupted loading of the tractor's reversing function.

[0024] The second pump body 4-2 operates intermittently under the control of the controller 10: the controller 10 controls the opening and closing of the on / off control valve of the second pump body 4-2 according to a preset cycle (such as working for a period of time and then stopping for a period of time), and simultaneously switches the position of the three-position four-way directional valve 14; when it is necessary to simulate heavy load loading, the three-position four-way directional valve 14 switches to the left position, the P port is connected to the A port, the second branch enters the oil, the oil pressure quickly rises to 20 MPa, the lifting oil of the implement returns to the hydraulic oil tank 1 through the B port and the T port, at this time the internal high pressure of the hydraulic pump is established instantaneously, and the heavy load working condition simulation is completed; after the preset running time, the controller 10 switches the directional valve to the right position, at this time the P port is connected to the B port, the external implement is lifted, the heavy load working condition oil returns to the oil tank through the A port and the T port, realizing unloading; when switched to the middle position, the second branch stops supplying oil, and the second pump body 4-2 enters the standby state;

[0025] The above-mentioned intermittent workflow is executed cyclically. Throughout the process, the first pump body 4-1 remains continuously running, unaffected by the start and stop of the second pump body 4-2. The two pump bodies work independently and do not interfere with each other, realistically replicating the working condition of continuous operation of the basic power function and intermittent triggering of the heavy-load loading function in actual tractor operation. At the same time, high-temperature tests can be conducted by heating the hydraulic oil tank 1 using heater 18: the hydraulic circuit oil is heated to the set temperature, temperature sensors and flow sensors are installed at the inlet and outlet of the dual hydraulic pump 4, and the second loading unit is controlled to maintain a constant high pressure of 20 MPa for 60 minutes. The inlet and outlet temperatures and flow rates are recorded every 10 minutes, and the temperature difference and flow rate deviation are analyzed to determine the high-temperature working performance of the hydraulic pump. A cooler is used for circulating water cooling to ensure that the oil temperature is stable and the internal flow and pressure remain unchanged when the hydraulic pump is running at full power.

[0026] This testing system can also simultaneously conduct gear train strength tests and hydraulic pump performance impact verification tests: the second pump body 4-2 is controlled to run continuously for 500 hours. After the test, the engine gears and supporting transmission components are disassembled and inspected, with a focus on checking damage such as tooth surface contact fatigue, tooth root bending fatigue, tooth surface scuffing, broken teeth, and failure of supporting bearings. At the same time, the system monitors the impact of hydraulic pump pressure changes on the engine's main oil passage pressure under high-pressure continuous operation conditions, as well as the lubrication status of components such as bearings and pistons. Various engine performance indicators are collected throughout the process, and the data is analyzed to clarify the impact of the hydraulic pump status on the overall engine operating performance, completing a comprehensive verification of the engine and hydraulic pump's coordinated matching performance.

[0027] Through the above implementation, this dual-pump hydraulic loading test system can effectively simulate different working conditions of tractors (idling, operation, heavy load, etc.), and further comprehensively collect parameters such as pressure and flow rate, providing accurate verification for the strength of the engine wheel system, the integrity of the hydraulic pump mechanism, working performance and durability, while expanding the component testing capabilities under the overall engine condition.

[0028] The parts of this utility model not described in detail are prior art. It is obvious to those skilled in the art that this utility model is not limited to the details of the above exemplary embodiments, and that this utility model can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the above embodiments should be regarded as exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description. Therefore, it is intended to include all changes that fall within the meaning and scope of the equivalents of the claims in this utility model, and no reference numerals in the claims should be regarded as limiting the content of the claims.

Claims

1. A dual-pump hydraulic loading test system, characterized in that: The system includes a hydraulic oil tank (1) and a three-position four-way directional valve (14), as well as a double hydraulic pump (4) with a one-inlet and two-outlet structure formed by a first pump body (4-1) and a second pump body (4-2). The inlet of the double hydraulic pump (4) is connected to the hydraulic oil tank (1) through a main filter (2), and the two outlets of the double hydraulic pump (4) are connected to the hydraulic oil tank (1) through a first branch and a second branch corresponding to the first pump body (4-1) and the second pump body (4-2), respectively. A first pressure gauge (6) and a first flow meter (7) are connected in series on the first branch. Table (7) and the first back pressure valve (8), the first back pressure valve (8) is connected in parallel with the first relief valve (9); the second branch is connected in series with the second pressure gauge (12), the second flow meter (13), the P port and A port of the three-position four-way directional valve (14) and the second back pressure valve (15), the T port and B port of the three-position four-way directional valve (14) are respectively connected to the hydraulic oil tank (1) and the external agricultural implement lifting oil circuit, and the second branch section from the P port of the three-position four-way directional valve (14) to the outlet of the second back pressure valve (15) is connected in parallel with the second relief valve (16).

2. The dual-pump hydraulic loading test system according to claim 1, characterized in that: The system also includes a controller (10), which is connected to the second pump body (4-2) and the three-position four-way reversing valve (14) respectively.

3. The dual-pump hydraulic loading test system according to claim 1, characterized in that: The hydraulic oil tank (1) is equipped with a heater (18), a thermometer (21) and a level gauge (20).

4. The dual-pump hydraulic loading test system according to claim 3, characterized in that: The hydraulic oil tank (1) is equipped with a cooler (17).

5. The dual-pump hydraulic loading test system according to claim 1, characterized in that: The hydraulic oil tank (1) is connected to a discharge pipeline with a discharge valve (22).

6. The dual-pump hydraulic loading test system according to claim 1, characterized in that: The first branch and the second branch are connected to a circuit valve (19) near the hydraulic oil tank (1).

7. The dual-pump hydraulic loading test system according to claim 1, characterized in that: A vacuum pressure gauge (3) is connected to the pipeline between the main filter (2) and the inlet of the dual hydraulic pump (4).

8. The dual-pump hydraulic loading test system according to claim 1, characterized in that: A first filter (5) and a second filter (11) are connected in series on the first branch and the second branch near the outlet of the double hydraulic pump (4), respectively.

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