A hydraulic load-sensitive multi-way valve testing system

Abstract

This invention relates to a hydraulic load-sensitive multi-way valve testing system, comprising a driver, a load-sensitive pump assembly, a variable hydraulic resistance, a load-sensitive compensator, and a directional valve connected in series to form a hydraulic output circuit. The driver controls the load-sensitive pump assembly to drive hydraulic oil upwards, which then experiences a pressure drop after passing through the variable hydraulic resistance. Finally, the hydraulic oil is output through the directional valve. The load-sensitive compensator is connected to the directional valve. The load-sensitive pump assembly includes an output pump, a pressure control valve, and a flow control valve. The driver drives the output pump. The rod chamber of the output pump is connected to the pressure control valve and the flow control valve. The output pump is connected to the directional valve, and the variable hydraulic resistance is located between the output pump and the directional valve. The pressure control valve is connected to the flow control valve and is used to limit the maximum working pressure. The inlet of the flow control valve is connected to the inlet of the directional valve. This invention provides a hydraulic load-sensitive multi-way valve testing system with small measurement errors.

Description

Technical Field

[0001] This invention relates to a testing system, specifically a testing system for a hydraulic load-sensitive multi-way valve. Background Technology

[0002] Hydraulic load-sensitive systems are an important branch of multi-way valve hydraulic intelligent and energy-saving control, and their high efficiency and energy-saving advantages are widely used in various engineering machinery.

[0003] In traditional hydraulic load-sensitive systems, while the load-sensitive compensator can coordinate and control the flow and pressure of the output pump and save unnecessary power loss when performing multi-operation compound actions, it ignores the variable hydraulic resistance of the pipeline between the pump and the multi-way valve, such as pressure loss along the pipeline and liquid shock. These variable hydraulic resistances make it difficult to accurately know the pressure difference before and after the multi-way valve when it is working. When testing the hydraulic load-sensitive multi-way valve system, inaccurate flow rate and test values ​​smaller than the standard values ​​were observed. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a hydraulic load-sensitive multi-way valve testing system with small measurement errors.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A hydraulic output circuit is formed by interconnected actuators, a load-sensitive pump assembly, a variable hydraulic resistance, a load-sensitive compensator, and a directional valve. The actuator controls the load-sensitive pump assembly to drive hydraulic oil upwards and outputs it, which then experiences a pressure drop through the variable hydraulic resistance. Finally, the hydraulic oil is output through the directional valve. The load-sensitive compensator is connected to the directional valve. The load-sensitive pump assembly includes an output pump, a pressure control valve, and a flow control valve. The actuator drives the output pump. The rod chamber of the output pump is connected to the pressure control valve and the flow control valve. The output pump is connected to the directional valve and is variable in pressure. The hydraulic resistance is located between the output pump and the directional valve. The pressure control valve is connected to the flow control valve and is used to limit the maximum working pressure. The inlet of the flow control valve is connected to the inlet of the directional valve. The driver can be a motor. The output pump is used to provide flow and pressure to the hydraulic output circuit. The rod chamber of the output pump is connected to the pressure control valve and the flow control valve to avoid the waste of hydraulic energy. The pressure control valve is connected to the flow control valve to protect the system and limit the maximum working pressure of the system. The variable hydraulic resistance is set to simulate the effects of pressure drop caused by friction loss and liquid shock in actual pipelines.

[0006] The present invention is further configured such that: the output pump is a variable displacement piston pump, the output pump is provided with a load-sensitive loading block, the load-sensitive loading block is provided with a connecting hole, one end of the connecting hole is connected to the input port of the flow control valve, and the other end is connected to the input port of the reversing valve.

[0007] The invention is further configured to include an LS feedback oil circuit, which is connected to the other side of the flow control valve opposite to the input port and is used to coordinate the output flow and pressure of the output pump.

[0008] The present invention is further configured such that: the LS feedback oil circuit includes an LS throttling component and an LS overflow valve, the LS throttling component and the LS overflow valve are connected in parallel in the output oil circuit, and the LS throttling component is generally selected as a throttling orifice.

[0009] The present invention is further configured such that: the reversing valve is a three-position six-way valve, the load-sensitive compensator is a three-position three-way valve, the reversing valve has a lower port, a lower second port, a lower third port, an upper port, a pa port and a pb port, the load-sensitive compensator includes a lower port, an upper first port and an upper second port, the lower port is connected to the output pump, the lower second port is connected to the connecting hole, the lower third port is connected to the upper first port, the upper port is connected to the lower port, and the upper second port is connected to the LS feedback oil circuit.

[0010] The present invention is further configured to include a main relief valve, which is disposed between the output pump and the reversing valve and is used for high-pressure relief of the hydraulic output oil circuit.

[0011] In the load-sensitive pump assembly, a sealing ring groove is provided between the load-sensitive loading block, the pressure control valve, and the output pump.

[0012] Beneficial effects: The load-sensitive loading block is connected to the input of the directional valve, which solves the problem of unstable pressure difference across the directional valve caused by variable hydraulic resistance and improves the flow accuracy during testing of hydraulic load-sensitive multi-way valve systems; the external end of the load-sensitive loading block can be equipped with a G1 / 4 plug, which makes the connection simple and reliable and easy to apply to the hydraulic testing of multi-way valves. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the test principle of the present invention;

[0014] Figure 2 This is a schematic diagram of the load-sensitive pump assembly of the present invention;

[0015] Figure 3 This is the P-inlet of the load-sensitive pump assembly of the present invention;

[0016] Figure 4 This is a left view of the load-sensitive pump assembly of the present invention;

[0017] Figure 5 This is a cross-sectional view of the load-sensitive pump assembly AA of the present invention;

[0018] Figure 6 This is a schematic diagram of the reversing valve of the present invention;

[0019] Figure 7 This is a schematic diagram of the load-sensitive compensator of the present invention.

[0020] The reference numerals in the attached figures represent: 1. Actuator; 21. Output pump; 22. Pressure control valve; 23. Flow control valve; 24. Connecting port; 25. Load-sensitive loading block; 3. Variable hydraulic resistance; 4. LS relief valve; 5. LS throttling assembly; 6. Load-sensitive compensator; 61. Lower port; 62. Upper port; 63. Upper second port; 7. Reversing valve; 71. Lower port; 72. Lower second port; 73. Lower third port; 74. Upper port; 8. Main relief valve; pa, pa port; pb, pb port. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] As shown in Figure 1-7, this invention discloses a hydraulic load-sensitive multi-way valve testing system, comprising a connected actuator 1, a load-sensitive pump assembly, a variable hydraulic resistance 3, a load-sensitive compensator 6, and a directional valve 7, forming a hydraulic output oil circuit. The actuator 1 controls the load-sensitive pump assembly to drive the hydraulic oil to output, and the hydraulic oil is pressure-dropped after passing through the variable hydraulic resistance 3. Finally, the hydraulic oil is output through the directional valve 7. The load-sensitive compensator 6 is connected to the directional valve 7. The load-sensitive pump assembly includes an output pump 21, a pressure control valve 22, and a flow control valve 23. The actuator 1 drives the output pump 21. The rod chamber pipeline of the output pump 21 is connected to the pressure control valve 22 and the flow control valve 23. The output pump 21 is connected to the directional valve 7. The variable hydraulic resistance 3 is connected between the output pump 21 and the reversing valve 7. The pressure control valve 22 is connected to the flow control valve 23 and is used to limit the maximum working pressure. The input port of the flow control valve 23 is connected to the input port of the reversing valve 7. The driver 1 can be a motor. The output pump 21 is used to provide flow and pressure to the hydraulic output circuit. The rod chamber of the output pump 21 is connected to the pressure control valve 22 and the flow control valve 23 to avoid the waste of hydraulic energy. The pressure control valve 22 is connected to the flow control valve 23 to protect the system and limit the maximum working pressure of the system. The variable hydraulic resistance 3 is set to simulate the pressure drop caused by friction loss and liquid shock in the actual pipeline.

[0024] The output pump 21 is a variable displacement piston pump. The output pump 21 is equipped with a load-sensitive loading block 25. The load-sensitive loading block 25 is equipped with a connecting hole 23. One end of the connecting hole 23 is connected to the input port of the flow control valve 23, and the other end is connected to the input port of the reversing valve 7.

[0025] It includes the LS feedback oil circuit, which is connected to the other side of the flow control valve 23 opposite to the input port and is used to coordinate the output flow and pressure of the output pump 21.

[0026] The LS feedback oil circuit includes the LS throttling component 5 and the LS relief valve 4. The LS throttling component 5 and the LS relief valve 4 are connected in parallel in the output oil circuit. The LS throttling component 5 is generally selected as a throttling orifice.

[0027] The directional valve 7 is a three-position six-way valve, and the load-sensitive compensator 6 is a three-position three-way valve. The directional valve 7 has a lower port 71, a lower second port 72, a lower third port 73, an upper port 74, a pa port, and a pb port. The load-sensitive compensator 6 includes a lower port 61, an upper port 62, and an upper second port 63. The lower port 71 is connected to the output pump 21, the lower second port 72 is connected to the connecting hole 23, the lower third port 73 is connected to the upper port 62, the upper port 74 is connected to the lower port 61, and the upper second port 63 is connected to the LS feedback oil circuit.

[0028] It includes a main relief valve 8, which is located between the output pump 21 and the reversing valve 7 and is used for high-pressure relief of the hydraulic output oil circuit. In the load-sensitive pump assembly, a sealing ring groove is provided between the load-sensitive loading block 25, the pressure control valve 22 and the output pump 21.

[0029] The mathematical equation for the testing principle is as follows:

[0030] The flow formula for a traditional hydraulic load-sensitive multi-way valve system is:

[0031]

[0032] Among them, C q A and ρ can be approximated as positive constants. Δp is the pressure drop across directional valve 7. The flow rate Q of directional valve 7 is positively correlated with its pressure drop Δp. However, in practical applications, the pressure drop across directional valve 7 is expressed as:

[0033] Δp=Δp 液阻 +k 弹簧

[0034] Where, k 弹簧 The spring force of the load-sensitive compensator 6; Δp 液阻 The pressure drop is due to the variable liquid resistance 3.

[0035] As shown in section 2, the pressure drop Δp across the reversing valve 7 will be affected by the variable hydraulic resistance 3Δp. 液阻 Due to the presence of [something], the flow rate Q during testing is smaller than the standard value, resulting in lower flow test accuracy for load-sensitive multi-way valve systems.

[0036] If the inlet of the flow control valve 23 is changed from before the variable hydraulic resistance 3 in the pipeline to the inlet of the directional valve 7, the pressure drop across the directional valve 7 system becomes:

[0037] Δp=k 弹簧

[0038] Therefore, based on the testing principle of 3, the influence of the variable hydraulic resistance 3 in the pipeline is solved, and the flow accuracy of the hydraulic load-sensitive multi-way valve system is improved during testing.

[0039] In practice:

[0040] The driver 1 controls the output pump 21 to output hydraulic pressure. The hydraulic oil passes through the variable hydraulic resistance 3, resulting in a certain pressure drop. The pressure of the fluid after the pressure drop is set not to exceed the limit pressure of the main relief valve 8, and the fluid flows to the input end of the reversing valve 7. Figure 1As shown, when the directional valve 7 is in the left position, the fluid first passes through the directional valve 7 and the load-sensitive compensator 6 before flowing back to the directional valve 7. Pb connects to the external load, and Pa connects to the return oil. When the multi-way valve system is working, the LS control oil circuit connects to the high-pressure point on the left side of the load-sensitive compensator 6. The load-sensitive compensator 6 is in either the middle or right position. Similarly, when the directional valve 7 is in the right position, Pb connects to the return oil, and Pa connects to the external load.

[0041] The hydraulic fluid at the input end of the directional valve 7 is connected to the load-sensitive pump assembly via the load-sensitive loading block 25. The working process is as follows: Figure 1 As shown, if the working pressure of the liquid exceeds the limit pressure, the pressure control valve 22 will switch to the left working position, and the liquid pressure will push the variable piston rod of the output pump 21 to move to the left, and the output pump 21 will reduce its displacement. If the liquid pressure is less than the limit pressure, when the flow control valve 23 is working in the right position, the output pump 21 will increase its displacement. When the flow control valve 23 is working in the left position, the output pump 21 will decrease its displacement. Because the flow control valve 23 is equipped with sensors for flow and pressure, it will detect the load end of the load-sensitive compensator 6 connected to the LS control oil circuit in real time. Therefore, it is possible to coordinate and control the output flow and pressure of the pump.

Claims

1. A hydraulic load-sensitive multi-way valve testing system, comprising a connected actuator (1), a load-sensitive pump assembly, a variable hydraulic resistance (3), a load-sensitive compensator (6), and a directional valve (7) forming a hydraulic output oil circuit, wherein the actuator (1) controls the load-sensitive pump assembly to drive hydraulic oil to output and generate a pressure drop through the variable hydraulic resistance (3), and finally outputs the hydraulic oil through the directional valve (7), and the load-sensitive compensator (6) is connected to the directional valve (7), characterized in that: The load-sensitive pump assembly includes an output pump (21), a pressure control valve (22), and a flow control valve (23). A driver (1) drives the output pump (21). The rod chamber of the output pump (21) is connected to the pressure control valve (22) and the flow control valve (23). The output pump (21) is connected to a reversing valve (7), and a variable hydraulic resistance (3) is located between the output pump (21) and the reversing valve (7). The pressure control valve (22) is connected to the flow control valve (23) and is used to limit the maximum working pressure. The inlet of the flow control valve (23) is connected to the inlet of the reversing valve (7). The assembly includes an LS feedback oil circuit, which is connected to the other side of the flow control valve (23) opposite to its inlet and is used to coordinate the output flow and pressure of the output pump (21). The reversing valve (7) is a three-position six-way valve, and the load-sensitive compensator (6) is a three-position three-way valve. The reversing valve (7) has a next port (71) and a next two port (72). 72) Lower three-way port (73), upper port (74), pa port and pb port, load sensitive compensator (6) includes lower port (61), upper port (62) and upper two port (63), lower port (71) is connected to output pump (21), lower two port (72) is connected to connecting hole, lower three-way port (73) is connected to upper port (62), upper port (74) is connected to lower port (61), upper two port (63) is connected to LS feedback oil circuit. When the directional valve (7) is in the left position, the fluid will first pass through the directional valve (7), the load-sensitive compensator (6), and then flow back to the directional valve (7). Pb connects to the external load, and Pa connects to the return oil. When the multi-way valve system is working, the LS control oil circuit will connect to the high-pressure point of the left position of the load-sensitive compensator (6), while the load-sensitive compensator (6) is in the middle or right position. Similarly, when the directional valve (7) is in the right position, Pb connects to the return oil, and Pa connects to the external load.

2. The hydraulic load-sensitive multi-way valve testing system according to claim 1, characterized in that: The output pump (21) is a variable displacement piston pump. The output pump (21) is provided with a load-sensitive loading block (25). The load-sensitive loading block (25) is provided with a connecting hole. One end of the connecting hole is connected to the input port of the flow control valve (23), and the other end is connected to the input port of the reversing valve (7).

3. The hydraulic load-sensitive multi-way valve testing system according to claim 1, characterized in that: The LS feedback oil circuit includes an LS throttling component (5) and an LS overflow valve (4), which are connected in parallel in the output oil circuit.

4. The hydraulic load-sensitive multi-way valve testing system according to claim 1, characterized in that: Includes a main relief valve (8), which is located between the output pump (21) and the directional valve (7) and is used for high-pressure relief of the hydraulic output oil circuit.

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