Hydraulic valve multifunctional pump source and control switching method thereof

Abstract

The hydraulic valve multifunctional pump source comprises two two-position three-way electromagnetic valves, a proportional overflow valve, a safety overflow valve and a pilot proportional direction valve, and is characterized by further comprising an Ls electrical unauthorized load sensitive pump, and a fixed-frequency motor is arranged on the Ls electrical unauthorized load sensitive pump in a matched mode; an outlet of the Ls electrical unauthorized load sensitive pump is connected with the pilot proportional direction valve; a C port of the first two-position three-way electromagnetic valve is connected with an Ls port of the Ls electrical unauthorized load sensitive pump, an A port of the first two-position three-way electromagnetic valve is connected to an outlet of the pilot proportional direction valve, and a B port of the first two-position three-way electromagnetic valve is connected with an Ls feedback port of the tested valve; a port C of the second two-position three-way solenoid valve is connected with a port P1 of the Ls electrical unauthorized load sensitive pump, a port A is connected with an inlet of the pilot proportional direction valve, and a port B is connected with a port P of the tested valve. The test bench can be compatible with tests of various hydraulic valves such as an overflow valve, is high in adjustment precision, and eliminates the influence of pipeline pressure loss on a test result.

Description

Technical Field

[0001] The present invention relates to hydraulic transmission and control technologies, and particularly to a multi-functional pump source for a hydraulic valve and its control switching method. Background Art

[0002] In a hydraulic valve test bench, there are various types of hydraulic valves to be tested, including pressure valves, multi-way valves, etc. Typical factory test items include steady-state pressure-flow characteristic tests, pressure loss tests, flow micro-motion tests, output flow-input signal characteristic tests under constant pressure drop, internal leakage tests, etc. When conducting steady-state pressure-flow characteristic tests and pressure loss tests, the pump source needs to be in the working mode of an electro-hydraulic proportional variable pump and be able to precisely adjust the flow rate; when conducting output flow-input signal characteristic tests under constant pressure drop, the pump source needs to be in the working mode of a load-sensing variable pump; when conducting internal leakage detection tests, the pump source needs to be in the working mode of a constant-pressure variable pump and can remotely adjust the constant pressure. Given the above requirements, the pump source of the hydraulic valve test bench needs to have extremely high flexibility to be compatible with various test items of different types of hydraulic valves.

[0003] Due to different operating conditions, the working pressure difference of the load-sensing multi-way valve will also be different; when conducting output flow-input signal characteristic tests under constant pressure drop, it is necessary to adjust the pressure difference of the pump source according to the working pressure difference of the multi-way valve. In the prior art, only the flow compensation valve of the pump can be manually adjusted, and since the distance between the energy pump and the multi-way valve to be tested is relatively far, it directly affects the test results.

[0004] Meanwhile, when conducting test items such as hydraulic valve pressure loss detection, it is necessary to precisely and quickly control the flow rate of the pump source. In the prior art, the method of adjusting the flow rate by using a variable-frequency motor to control a load-sensing variable pump has low control accuracy and slow response due to the influence of the low-speed performance of the load-sensing variable pump and the acceleration and deceleration time of the frequency converter. Currently, there is no test bench energy source that can comprehensively meet the above requirements and achieve automatic and rapid switching of working modes. Summary of the Invention

[0005] The purpose of the present invention is to solve the above problems and provide a multi-functional pump source for a hydraulic valve and its control switching method, which has the characteristics that the pump source of the test bench can be basically compatible with the power source supply of various hydraulic valves.

[0006] The above technical problems of the present invention are mainly solved by the following technical solution: A multi-functional pump source for a hydraulic valve includes a first two-position three-way solenoid valve, a second two-position three-way solenoid valve, a proportional relief valve, a safety relief valve, and a pilot proportional direction valve with an outlet connected to the test bench system, and is characterized in that it further includes an Ls electrically overriding load-sensing pump, and a fixed-frequency motor is provided for the Ls electrically overriding load-sensing pump.

[0007] The inlet of the Ls electrical unauthorized load-sensitive pump is connected to the oil tank, and the outlet is connected to the pilot proportional direction valve.

[0008] The C port of the first two-position three-way solenoid valve is connected to the Ls port of the Ls electrical unauthorized load-sensitive pump, the A port of the first two-position three-way solenoid valve is connected to the outlet of the pilot proportional direction valve, and the B port is connected to the Ls feedback port of the valve under test.

[0009] The C port of the second two-position three-way solenoid valve is connected to the P1 port of the Ls electrical unauthorized load-sensitive pump, the A port is connected to the inlet of the pilot proportional direction valve, and the B port is connected to the P port of the valve under test.

[0010] In the aforementioned hydraulic valve multi-functional pump source, preferably, an Ls electrical unauthorized control valve and a load-sensitive compensation valve are integrated in the Ls electrical unauthorized load-sensitive pump. The Ls electrical unauthorized control valve is a proportional pressure reducing valve; the working pressure difference of the Ls electrical unauthorized load-sensitive pump is adjusted by the Ls electrical unauthorized control valve.

[0011] In the aforementioned hydraulic valve multi-functional pump source, preferably, the safety relief valve is arranged at the outlet of the Ls electrical unauthorized load-sensitive pump, and a flow switch is connected to the outlet of the safety relief valve; the pressure of the safety relief valve is higher than the rated working pressure of the test bench.

[0012] In the aforementioned hydraulic valve multi-functional pump source, preferably, the proportional relief valve is arranged at the Ls port of the Ls electrical unauthorized load-sensitive pump, and the rated pressure of the proportional relief valve is lower than the set pressure of the safety relief valve.

[0013] In the aforementioned hydraulic valve multi-functional pump source, preferably, the first two-position three-way solenoid valve and the second two-position three-way solenoid valve are zero-leakage solenoid valves that can flow bidirectionally.

[0014] A control switching method for a hydraulic valve multi-functional pump source, characterized by comprising the following steps: ① When testing the steady-state pressure-flow characteristic test and the pressure loss test items, the pump source is switched to the electro-hydraulic proportional variable pump working mode, and the first two-position three-way solenoid valve and the second two-position three-way solenoid valve are energized. At this time, the constant pressure point of the pump source can be adjusted through the proportional relief valve, and the flow rate of the pump source can be adjusted through the pilot proportional direction valve.

[0015] ② When testing the output flow-input signal characteristic test under a constant pressure drop and the multi-way valve flow micro-movement test items, the pump source operates in the load-sensitive constant pressure variable pump mode, and the first two-position three-way solenoid valve and the second two-position three-way solenoid valve are de-energized, and the pilot proportional direction valve is fully opened.

[0016] ③ When the working pressure difference of the valve under test is inconsistent with the initial pressure difference of the pump source, the Ls electrical unauthorized control valve on the LS electrical unauthorized control load-sensitive pump can be adjusted to make the pressure difference reach the working pressure difference of the valve under test.

[0017] ④When testing items such as internal leakage and pressure resistance test, energize the first two-position three-way solenoid valve and the second two-position three-way solenoid valve, and fully open the pilot proportional direction valve. At this time, the pump source operates in the constant pressure variable pump mode.

[0018] In the aforementioned control switching method, when the pump source operates in the Ls electrical override load sensing pump mode and the first two-position three-way solenoid valve and the second two-position three-way solenoid valve are de-energized, the P port of the valve under test is connected to the P1 port of the Ls electrical override load sensing pump to eliminate the influence of pipeline pressure loss on the test results.

[0019] This technical solution changes the output flow of the pump source through the design of the Ls electrical override load sensing pump, combined with the pilot proportional direction valve, two-position three-way solenoid valve, etc. Its information feedback is provided by the P port and Ls port of the valve under test. And a safety overflow valve with a flow switch is set to protect the LS electrical override control load sensing pump. When a signal is detected, the program controls the fixed-frequency motor to stop.

[0020] Compared with the prior art, the beneficial effects of the present invention are: (1) During the test process, it can be switched between the constant pressure electro-hydraulic proportional variable pump working mode and the constant pressure load sensing variable pump working mode; thus enabling the test bench to be compatible with the testing of various hydraulic valves such as overflow valves, pressure reducing valves, proportional direction valves, and multi-way valves, and being able to simply and efficiently provide a power source for the factory test of hydraulic valves.

[0021] (2) When the pump source operates in the hydraulic electro-hydraulic proportional variable pump mode, by adjusting the pilot proportional direction valve, it is basically possible to achieve stepless adjustment of the pump source output flow from zero flow to maximum flow, with high adjustment accuracy and fast response.

[0022] (3) The setting of the Ls electrical override control load sensing variable pump enables easy adjustment of the pressure difference of the load sensing variable pump when the pressure difference needs to be changed, solving the problem that the working pressure difference of hydraulic valves is not unique and it is inconvenient to adjust the springs of the constant flow valves of load sensing pumps for different products.

[0023] (4) Connecting the P1 port of the Ls electrical override load sensing pump to the P port of the valve under test eliminates the influence of pipeline pressure loss on the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the hydraulic principle schematic diagram of the present invention

[0025] In the figure: 1-Ls electrical override load sensing pump; 2-proportional overflow valve; 3-first two-position three-way solenoid valve; 4-pilot proportional direction valve; 5-second two-position three-way solenoid valve; 6-safety overflow valve; 7-flow switch; 8-fixed-frequency motor; 9-Ls electrical override control valve; 10-load sensing compensation valve. Detailed implementation mode

[0026] The technical solution of the present invention will be further specifically described below through embodiments in combination with the accompanying drawings.

[0027] As Figure 1 shown, a multifunctional pump source for a hydraulic valve in this embodiment includes a first two-position three-way solenoid valve 3, a second two-position three-way solenoid valve 5, a proportional relief valve 2, a safety relief valve 6, and a pilot proportional direction valve 4 with an outlet connected to a test bench system. It also includes an Ls electrical override load-sensing pump 1, and a fixed-frequency motor 8 is provided for the Ls electrical override load-sensing pump.

[0028] The Ls electrical override load-sensing pump 1 includes a hydraulic pump and integrates an Ls electrical override control valve 9 and a load-sensing compensation valve 10, where the Ls electrical override control valve is a proportional pressure-reducing valve. The working pressure difference of the Ls electrical override load-sensing pump is adjusted by the Ls electrical override control valve; the load-sensing compensation valve 10 enables the hydraulic pump to obtain constant flow control.

[0029] The first two-position three-way solenoid valve 3 and the second two-position three-way solenoid valve 5 are zero-leakage solenoid valves that can flow bidirectionally.

[0030] The inlet of the Ls electrical override load-sensing pump 1 is connected to the fuel tank, the outlet is connected to the pilot proportional direction valve 4, and at the same time, the safety relief valve 6 is also connected to the outlet of the Ls electrical override load-sensing pump 1. A flow switch 7 is connected to the outlet of the safety relief valve 6. The function of the safety relief valve 6 is to protect the Ls electrical override load-sensing pump 1. The pressure of the safety relief valve 6 is higher than the rated working pressure of the test bench.

[0031] The C port of the first two-position three-way solenoid valve 3 is connected to the Ls port of the Ls electrical override load-sensing pump 1, the A port of the first two-position three-way solenoid valve 3 is connected to the outlet of the pilot proportional direction valve 4, and the B port is connected to the Ls feedback port of the valve under test; the C port of the second two-position three-way solenoid valve 5 is connected to the P1 port of the Ls electrical override load-sensing pump 1, the A port is connected to the inlet of the pilot proportional direction valve 4, and the B port is connected to the P port of the valve under test; the output flow of the multifunctional pump source for the hydraulic valve can be accurately and quickly adjusted.

[0032] The proportional relief valve 2 is arranged at the Ls port of the Ls electrical override load-sensing pump 1 for adjusting the constant pressure point of the pump source. The rated pressure of the proportional relief valve 2 is lower than the set pressure of the safety relief valve 6.

[0033] The multi-functional pump source of the hydraulic valve in this embodiment is mainly used for the factory test bench of hydraulic valves. It can adapt to test items such as steady-state pressure-flow characteristic test, pressure loss test (for electro-hydraulic proportional variable pump system), internal leakage detection, etc. (for constant pressure variable pump system), and can also adapt to test items such as output flow-input signal characteristic test under constant pressure drop, flow micro-motion test, etc. (for load-sensing variable pump system).

[0034] The control switching method of the multi-functional pump source of the hydraulic valve in this embodiment includes the following content: ① When testing steady-state pressure-flow characteristic test and pressure loss test items, the pump source switches to the electro-hydraulic proportional variable pump working mode, so that the first two-position three-way solenoid valve 3 and the second two-position three-way solenoid valve 5 are energized. At this time, the constant pressure point of the pump source can be adjusted through the proportional relief valve 2, and the flow rate of the pump source can be adjusted through the pilot proportional direction valve 4.

[0035] ② When the test items are output flow-input signal characteristic test under constant pressure drop and multi-way valve flow micro-motion test, the pump source switches to the load-sensing constant pressure variable pump mode. The first two-position three-way solenoid valve 3 and the second two-position three-way solenoid valve 5 are de-energized. The Ls port of the Ls electro-hydraulic override load-sensing pump 1 is connected to the Ls port of the multi-way valve, and the P1 port is connected to the P port of the multi-way valve. The pilot proportional direction valve 4 is fully opened.

[0036] ③ When the working pressure difference of the valve under test is inconsistent with the initial pressure difference of the pump source, the Ls electro-hydraulic override control valve 9 on the Ls electro-hydraulic override load-sensing pump 1 can be adjusted to make the pressure difference reach the working pressure difference of the valve under test.

[0037] ④ When testing items such as internal leakage and pressure resistance test, the pump source needs to work in the constant pressure variable pump mode, so that the first two-position three-way solenoid valve and the second two-position three-way solenoid valve are energized, and the pilot proportional direction valve is fully opened.

[0038] Furthermore, when the pump source works in the mode of the Ls electro-hydraulic override load-sensing pump 1 and the first two-position three-way solenoid valve 3 and the second two-position three-way solenoid valve 5 are de-energized, the P port of the valve under test is connected to the P1 port of the Ls electro-hydraulic override load-sensing pump 1 to eliminate the influence of pipeline pressure loss on the test results.

[0039] During the test process of this embodiment, without stopping the fixed-frequency motor 8, according to different test items, the pump source can achieve seamless switching among the constant pressure variable pump working mode, electro-hydraulic proportional variable pump and load-sensing variable pump working modes, and accurately and quickly provide the flow rate and pressure required for the test.

[0040] The above embodiments are illustrative of the present invention and not restrictive thereof. The described embodiments are only some of the embodiments of the present invention, not all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

Claims

1. A multi-functional pump source for a hydraulic valve, comprising a first two-position three-way solenoid valve (3), a second two-position three-way solenoid valve (5), a proportional relief valve (2), a safety relief valve (6), and a pilot proportional direction valve (4) with an outlet connected to a test bench system, characterized in that It also includes an Ls electrical override load sensing pump (1), and a fixed-frequency motor (8) is provided for the Ls electrical override load sensing pump; The inlet of the Ls electrical override load sensing pump is connected to the fuel tank, and the outlet is connected to the pilot proportional direction valve; The C port of the first two-position three-way solenoid valve is connected to the Ls port of the Ls electrical override load sensing pump, and the A port of the first two-position three-way solenoid valve is connected to the outlet of the pilot proportional direction valve, and the B port is connected to the Ls feedback port of the valve under test; The C port of the second two-position three-way solenoid valve is connected to the P1 port of the Ls electrical override load sensing pump, the A port is connected to the inlet of the pilot proportional direction valve, and the B port is connected to the P port of the valve under test.

2. The hydraulic valve multi-functional pump source according to claim 1, characterized in that, An Ls electrical override control valve (9) and a load sensing compensation valve (10) are integrated in the Ls electrical override load sensing pump (1). The Ls electrical override control valve is a proportional pressure reducing valve; the working pressure difference of the Ls electrical override load sensing pump is adjusted by the Ls electrical override control valve.

3. The hydraulic valve multi-functional pump source according to claim 1, characterized in that, The safety relief valve (6) is arranged at the outlet of the Ls electrical override load sensing pump (1), and a flow switch (7) is connected to the outlet of the safety relief valve; the pressure of the safety relief valve is higher than the rated working pressure of the test bench.

4. The hydraulic valve multi-functional pump source according to claim 3, characterized in that, The proportional relief valve (2) is arranged at the Ls port of the Ls electrical override load sensing pump (1), and the rated pressure of the proportional relief valve is lower than the set pressure of the safety relief valve (6).

5. The hydraulic valve multi-functional pump source according to claim 1, characterized in that, The first two-position three-way solenoid valve (3) and the second two-position three-way solenoid valve (5) are zero-leakage solenoid valves that can flow bidirectionally.

6. A control switching method for a multi-functional pump source of a hydraulic valve as described in any one of claims 1-5, characterized in that, It includes the following steps: ① When testing steady-state pressure-flow characteristic tests and pressure loss test items, the pump source switches to the electro-hydraulic proportional variable pump working mode, so that the first two-position three-way solenoid valve (3) and the second two-position three-way solenoid valve (5) are energized. At this time, the constant pressure point of the pump source can be adjusted through the proportional relief valve (2), and the pump source flow can be adjusted through the pilot proportional direction valve (4); ② When testing the output flow-input signal characteristic test under a constant pressure drop and the multi-way valve flow fine adjustment test items, the pump source operates in the load sensing constant pressure variable pump mode, so that the first two-position three-way solenoid valve and the second two-position three-way solenoid valve are de-energized, and the pilot proportional direction valve is fully open; ③ When the working pressure difference of the valve under test is inconsistent with the initial pressure difference of the pump source, the Ls electrical override control valve (9) on the LS electrical override control load sensing pump can be adjusted to make the pressure difference reach the working pressure difference of the valve under test; ④ When testing items such as internal leakage and pressure resistance tests, the first two-position three-way solenoid valve and the second two-position three-way solenoid valve are energized, and the pilot proportional direction valve is fully open. At this time, the pump source operates in the constant pressure variable pump mode.

7. The control switching method according to claim 6, wherein When the pump source operates in the Ls electrical override load sensing pump mode and the first two-position three-way solenoid valve and the second two-position three-way solenoid valve are de-energized, the P port of the valve under test is connected to the P1 port of the Ls electrical override load sensing pump to eliminate the influence of pipeline pressure loss on the test results.

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