High-flow servo valve oil supply test system

Abstract

The invention discloses a high-flow servo valve oil supply testing system which comprises an oil tank, a tested valve mounting table, a first oil pump, an oil supplementing module, a pressure balancing module and a measuring module. The tested valve mounting table is connected with the first oil pump, the oil supplementing module and the oil tank, a to-be-measured servo valve is mounted on the tested valve mounting table, the first oil pump is connected with the oil tank and is suitable for pilot oil supply to the to-be-measured servo valve, the oil supplementing module is suitable for oil supply testing to the to-be-measured servo valve, and the measuring module is used for monitoring the flow of the oil supplementing module. The flow characteristic of the to-be-measured servo valve is fed back; and the pressure balancing module is connected with the oil supplementing module to balance the pressure lost by the oil supplementing module in the oil supply process. The system has the advantages that the pressure balancing module is arranged to balance the working pressure of the oil supplementing module, so that the oil supplementing module outputs the oil pressure tending to a constant value to the to-be-measured servo valve, and then the flow testing stability of the large-flow servo valve is improved.

Description

Technical Field

[0001] The present application relates to the field of valve technology, and in particular to a large-flow servo valve oil supply test system. Background Art

[0002] Servo valve is a commonly used valve element in hydraulic systems. Servo valves can be divided into small-flow servo valves and large-flow servo valves according to the usage scenarios. Regardless of the type of servo valve, it needs to be flow tested before use.

[0003] Due to the structural characteristics of large-flow servo valves, it is difficult or impossible to measure the full stroke of existing test benches, and thus it is impossible to obtain the flow characteristics of the full stroke, and its step response characteristics or frequency characteristics can only be measured when it is no-load. At the same time, for large-flow servo valves, the influence of hydraulic force will also become greater, so that the step response time under pressure will be affected relative to no-load. Moreover, for large-diameter two-way cartridge servo valves, a pilot valve is generally used as the power to drive the main valve, so the oil supply pressure of the pilot valve will also affect the response speed of the main valve core. Summary of the invention

[0004] One of the purposes of the present application is to provide a large flow servo valve oil supply test system that can solve at least one defect in the above-mentioned background technology.

[0005] In order to achieve at least one of the above-mentioned purposes, the technical solution adopted in the present application is: a large-flow servo valve oil supply test system, including an oil tank, a tested valve mounting platform, a first oil pump, an oil replenishment module, a pressure balancing module and a measuring module; the tested valve mounting platform is respectively connected to the first oil pump, the oil replenishment module and the oil tank, the servo valve to be measured is installed on the tested valve mounting platform, the first oil pump is connected to the oil tank and is suitable for pilot oil supply to the servo valve to be measured, the oil replenishment module is suitable for performing an oil supply test on the servo valve to be measured, the measuring module is used to monitor the flow of the oil replenishment module, and then provide feedback on the flow characteristics of the servo valve to be measured; the pressure balancing module is connected to the oil replenishment module to balance the pressure lost by the oil replenishment module during the oil supply process.

[0006] Preferably, the oil replenishment module includes a first piston accumulator, a gas cylinder group and a second oil pump; the first piston accumulator is connected to the measured valve mounting platform through the oil pressure end for supplying oil to the servo valve to be measured, and the gas cylinder group is connected to the air pressure end of the first piston accumulator for replenishing air to the first piston accumulator; the pressure balancing module is suitable for being connected to the gas cylinder group for balancing the air supply pressure of the gas cylinder group; the input end of the second oil pump is connected to the oil tank, and the output end of the second oil pump is connected to the oil pressure end of the first piston accumulator through a first one-way valve.

[0007] Preferably, the measurement module includes a displacement measuring unit and a servo valve testing system; the displacement measuring unit is used to collect piston movement data of the first piston accumulator, and the servo valve testing system is signal-connected to the displacement measuring unit to receive the data collected by the displacement measuring unit, and then calculates the current flow rate passing through the servo valve to be measured based on the piston diameter of the first piston accumulator.

[0008] Preferably, an overflow valve, a second pressure sensor and a diaphragm accumulator are installed in parallel at the output end of the first oil pump; the diaphragm accumulator is used to stabilize the pilot oil pressure output by the first oil pump to the servo valve to be measured; the overflow valve is connected to the oil tank, and the overflow valve is suitable for regulating the pilot oil pressure; the second pressure sensor is used to display the pilot oil pressure.

[0009] Preferably, the pressure balancing module comprises a second piston accumulator, a third piston accumulator and a control valve group; the air pressure end of the second piston accumulator is connected to the gas cylinder group, and the oil pressure end of the second piston accumulator is connected to the oil pressure end of the third piston accumulator and the oil tank through the control valve group; when the air pressure of the gas cylinder group is greater than a set value, the second piston accumulator is suitable for returning the oil at the oil pressure end to the oil tank through the control valve group, so that the gas cylinder group replenishes air and reduces the pressure to the second piston accumulator; when the air pressure of the gas cylinder group is less than the set value, the third piston accumulator replenishes oil to the oil pressure end of the second piston accumulator through the control valve group, so that the second piston accumulator replenishes air and increases the pressure to the gas cylinder group.

[0010] Preferably, the control valve group includes a first cartridge valve, a second cartridge valve and a pilot valve; the oil pressure end of the second piston accumulator is connected to the oil tank through the first cartridge valve, the third piston accumulator is connected to the second piston accumulator through the second cartridge valve, and the pilot valve is connected to the first cartridge valve and the second cartridge valve respectively; when the air pressure of the gas cylinder group is greater than a set value, the pilot valve controls the first cartridge valve to open and controls the second cartridge valve to close; when the air pressure of the gas cylinder group is less than a set value, the pilot valve controls the first cartridge valve to close and controls the second cartridge valve to open.

[0011] Preferably, the control valve group further includes a servo valve, and the oil pressure end of the second piston accumulator is connected to the first cartridge valve and the second cartridge valve respectively through the servo valve.

[0012] Preferably, when the absolute value of the difference ΔP between the actual gas pressure P1 of the gas cylinder group and the set value P is less than a set threshold, the control valve group is in an isolated state; when the absolute value of the difference ΔP between the actual gas pressure P1 of the gas cylinder group and the set value P is greater than a set threshold, the control valve group performs pressure balancing work of the gas cylinder group, and at this time, the control signal U of the servo valve is: ; Among them, K p Represents the proportionality coefficient, K i represents the integration constant, K d represents the differential constant, and S represents the sampling period.

[0013] Preferably, the pressure balancing module also includes a third oil pump and a second one-way valve; the input end of the third oil pump is connected to the oil tank, and the output end of the third oil pump is connected to the oil pressure end of the third piston accumulator through the second one-way valve, so that the third piston accumulator is replenished with oil through the third oil pump; the third piston accumulator is suitable for replenishing oil through the third oil pump until the oil pressure end reaches a maximum volume before the second piston accumulator supplies gas to the gas cylinder group.

[0014] Preferably, the large-flow servo valve oil supply test system also includes a controller, and the oil pressure end of the first piston accumulator is also connected to a first pressure sensor; the controller is respectively connected to the first pressure sensor, the measuring module and the pressure balance module for signal connection; the controller controls the pressure balance module to perform pressure balancing according to the collected data of the first pressure sensor; the controller controls the servo valve to be measured according to the collected data of the measuring module.

[0015] Compared with the prior art, the beneficial effects of this application are: During the servo valve flow test, a pressure balancing module is set to balance the working pressure of the oil replenishment module, so that the oil replenishment module outputs an oil pressure tending to a constant value to the servo valve to be measured, thereby improving the flow test stability of the large-flow servo valve and thus improving the test accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the overall structure of this application.

[0017] In the figure: a tested valve mounting platform 101, a gas cylinder group 102, a first piston accumulator 103, a first pressure sensor 104, a displacement measuring unit 105, a servo valve testing system 106, a second pressure sensor 107, a diaphragm accumulator 108, a first oil pump 109, a second oil pump 110, a first non-return valve 111, a second piston accumulator 201, a first travel switch 203, a third piston accumulator 204, a second travel switch 205, a servo valve 206, a first cartridge valve 207, a second cartridge valve 208, a second non-return valve 209, a pilot valve 210, a third oil pump 211, an oil tank 300, and a controller 400. DETAILED DESCRIPTION

[0018] Below, the present application is further described in conjunction with specific implementation methods. It should be noted that in the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms should not be understood as necessarily being directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0019] In the description of the present application, it should be noted that directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions and positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of narrating the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific scope of protection of the present application.

[0020] It should be noted that the terms "first", "second", etc. in the description and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0021] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be connected, detachably connected, or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0023] The terms "including" and "having" and any variations thereof in the specification and claims of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0024] One of the preferred embodiments of the present application is as follows: Figure 1As shown, a large flow servo valve oil supply test system includes an oil tank 300, a tested valve mounting platform 101, a first oil pump 109, an oil replenishment module, a pressure balance module and a measurement module. The tested valve mounting platform 101 is provided with a corresponding installation interface, and the servo valve to be measured can connect its own oil inlet and oil outlet with the tested valve mounting platform 101, so that the servo valve to be measured is installed on the tested valve mounting platform 101. The input end of the first oil pump 109 is connected to the oil tank 300, and the output end of the first oil pump 109 is connected to one of the oil inlets of the tested valve mounting platform 101, and then when the flow test of the servo valve to be measured is performed, the first oil pump 109 can pilot the oil supply to the servo valve to be measured, thereby controlling the valve core operation of the servo valve to be measured. The oil replenishment module is connected to another oil inlet of the valve mounting platform 101 to be measured, so that the oil replenishment module can supply oil to the servo valve to be measured during the flow test of the servo valve to be measured; accordingly, the valve mounting platform 101 to be measured is also connected to the oil tank 300 through the oil outlet, so that the pilot oil and working oil entering the servo valve to be measured can flow back to the oil tank 300 through the corresponding oil outlet. The measurement module is used to monitor the flow of the oil replenishment module, and then feedback the flow characteristics of the servo valve to be measured; the pressure balance module is connected to the oil replenishment module to balance the pressure lost by the oil replenishment module during the oil supply process.

[0025] It is understandable that when a conventional test bench tests a large flow servo valve, as the test process of the large flow servo valve proceeds, the working pressure of the oil replenishment module used to supply oil to the test bench will gradually decrease, thereby causing inaccurate flow test of the large flow servo valve. In the technical solution of the present application, a pressure balancing module is provided to balance the working pressure of the oil replenishment module, so that the oil replenishment module outputs a constant oil pressure to the servo valve to be measured, thereby improving the flow test stability of the large flow servo valve, thereby improving the test accuracy.

[0026] It should be known that the specific structure and working principle of the tested valve mounting platform 101 are basically consistent with the structure of the traditional test platform, which is well known to those skilled in the art, so it will not be described in detail here. The specific structure and working principle of the first oil pump 109 and the subsequent second oil pump 110 and the third oil pump 211 are well known to those skilled in the art, so it will not be described in detail here.

[0027] In this embodiment, there are many specific structures of the oil replenishment module that can achieve the above functions. For the sake of easy understanding, the following will be described in detail using one specific structure. Figure 1As shown, the oil replenishment module includes a first piston accumulator 103, a gas cylinder group 102 and a second oil pump 110. The first piston accumulator 103 includes a pneumatic end and an oil pressure end based on its own structure. The first piston accumulator 103 is connected to the valve mounting platform 101 to be measured through the oil pressure end, so that during the flow test of the servo valve to be measured, the first piston accumulator 103 can supply oil to the servo valve to be measured. The gas cylinder group 102 is connected to the pneumatic end of the first piston accumulator 103, so that during the flow test of the servo valve to be measured, the gas cylinder group 102 can replenish gas to the pneumatic end of the first piston accumulator 103 to ensure that the first piston accumulator 103 can work normally. The pressure balance module can be connected to the gas cylinder group 102, so that during the flow test of the servo valve to be measured, the pressure balance module can be used to balance the gas supply pressure of the gas cylinder group 102 to ensure that the pressure of the pneumatic end of the first piston accumulator 103 tends to a constant value. The input end of the second oil pump 110 is connected to the oil tank 300, and the output end of the second oil pump 110 is connected to the oil pressure end of the first piston accumulator 103 through the first one-way valve 111, so that before the flow test of the servo valve to be tested, the second oil pump 110 can replenish oil to the oil pressure end of the first piston accumulator 103 to ensure that the first piston accumulator 103 has enough oil for the test of the large-flow servo valve. The first one-way valve 111 can ensure that the oil output by the first piston accumulator 103 only flows to the valve mounting platform 101 to be tested.

[0028] It should be known that the first piston accumulator 103 and the subsequent second piston accumulator 201 and the third piston accumulator 204 all form a two-end structure through the piston, one end of which is used to accommodate gas and the other end is used to accommodate oil; the end that accommodates gas is the gas pressure end, and the end that accommodates oil is the oil pressure end. When the pressure at the gas pressure end is greater than the pressure at the oil pressure end, the piston will move toward the oil pressure end under the action of the gas pressure, thereby increasing the volume of the gas pressure end and reducing the volume of the oil pressure end; conversely, when the pressure at the gas pressure end is less than the pressure at the oil pressure end, the piston will move toward the gas pressure end under the action of the oil pressure, thereby reducing the volume of the gas pressure end and increasing the volume of the oil pressure end.

[0029] In this embodiment, based on the specific structure of the above-mentioned oil replenishment module, there are multiple specific structures of the measurement module for collecting the flow of the first piston accumulator 103. For the sake of easy understanding, one of the structures will be described in detail below. Figure 1As shown, the measurement module includes a displacement measurement unit 105 and a servo valve test system 106. The displacement measurement unit 105 is used to collect the piston movement data of the first piston accumulator 103, and the servo valve test system 106 is connected to the displacement measurement unit 105 by signal to receive the data collected by the displacement measurement unit 105, and then calculates the current flow rate passing through the servo valve to be measured according to the piston diameter of the first piston accumulator 103.

[0030] It can be understood that the piston movement data of the first piston accumulator 103 collected by the displacement measurement unit 105 includes the movement speed V of the piston. According to the diameter D of the piston, the flow rate Q passing through the servo valve to be measured can be obtained as follows: 2 ×V. There are many specific ways to test the piston movement speed V of the first piston accumulator 103, that is, there are many specific structures of the displacement measurement unit 105. For easy understanding, a specific example will be used for detailed description below.

[0031] Specifically, the displacement measuring unit 105 includes a grating ruler connected to the piston of the first piston accumulator 103, and a fixed grating displacement sensor; the specific structure and working principle of the grating ruler and the grating displacement sensor are well-known technologies for those skilled in the art, so they will not be elaborated in detail here. When the first piston accumulator 103 is supplying oil, the piston will drive the grating ruler to move synchronously, and then the moving distance of the grating ruler can be obtained through the grating displacement sensor, and the moving speed V of the piston can be calculated in combination with the oil supply duration of the first piston accumulator 103.

[0032] It can also be understood that the servo valve test system 106 can also be used to send a control signal to the servo valve to be measured, and can also collect and record the valve core displacement data of the servo valve to be measured. Assuming that the control signal corresponding to the valve core opening of the servo valve to be measured is 0-10V, then the feedback signal of the valve core after moving is also 0-10V, then the servo valve test system 106 only needs to judge whether the valve core is in place according to the specific value of the feedback signal. The specific structure and working principle of the servo valve test system 106 are well-known technologies for those skilled in the art, so they will not be elaborated in detail here.

[0033] In this embodiment, Figure 1As shown, the output end of the first oil pump 109 is connected in parallel with a relief valve, a second pressure sensor 107 and a diaphragm accumulator 108. The diaphragm accumulator 108 is used to stabilize the pilot oil pressure output by the first oil pump 109 to the servo valve to be measured; that is, when the oil pressure output by the first oil pump 109 fluctuates, the diaphragm accumulator 108 suppresses the fluctuation of the output oil pressure of the first oil pump 109 by replenishing or discharging oil, thereby stabilizing the pilot oil pressure of the servo valve to be measured. The relief valve is connected to the oil tank 300, and the relief valve can adjust the pilot oil pressure, thereby realizing the step response test of the servo valve to be measured under different pilot oil pressures. The second pressure sensor 107 is used to display the pilot oil pressure. The servo valve test system 106 can be connected to the second pressure sensor 107 for signal connection, and then the data of the second pressure sensor 107 is collected and fed back to the subsequent controller 400.

[0034] It should be known that the specific structures and working principles of the overflow valve, the diaphragm accumulator 108, the second pressure sensor 107 and the subsequent first pressure sensor 104 are well-known technologies to those skilled in the art, and therefore will not be elaborated in detail herein.

[0035] In this embodiment, the specific activation of the pressure balance module is based on the response to the output pressure change of the first piston accumulator 103. There are many specific ways to monitor the output pressure of the first piston accumulator 103, such as Figure 1 As shown, a first pressure sensor 104 may be connected in parallel to the output end of the first piston accumulator 103 , and the first pressure sensor 104 may collect the output pressure of the first piston accumulator 103 , and then the response of the pressure balance module may be controlled by acquiring data from the first pressure sensor 104 .

[0036] In this embodiment, there are many specific structures of the pressure balance module that can achieve the above functions. For the sake of easy understanding, one of the structures will be described in detail below. Figure 1 As shown, the pressure balance module includes a second piston accumulator 201, a third piston accumulator 204 and a control valve group. The air pressure end of the second piston accumulator 201 is connected to the gas cylinder group 102, and the oil pressure end of the second piston accumulator 201 is connected to the oil pressure end of the third piston accumulator 204 and the oil tank 300 through the control valve group. When the air pressure of the gas cylinder group 102 is greater than the set value, the second piston accumulator 201 is suitable for returning the oil at the oil pressure end to the oil tank 300 through the control valve group, so that the gas cylinder group 102 replenishes air to the second piston accumulator 201 and reduces the pressure. When the air pressure of the gas cylinder group 102 is less than the set value, the third piston accumulator 204 replenishes oil to the oil pressure end of the second piston accumulator 201 through the control valve group, so that the second piston accumulator 201 replenishes air to the gas cylinder group 102 and increases the pressure.

[0037] It is understandable that the function of the second piston accumulator 201 is to achieve rapid pressure balance of the gas cylinder group 102 through the volume change of the gas pressure end. Since the pressure of the gas cylinder group 102 is always the same as that of the gas pressure end of the second piston accumulator 201, when the working pressure of the gas cylinder group 102 is greater than the set value, the oil at the oil pressure end of the second piston accumulator 201 can be discharged to increase the volume of the gas pressure end of the second piston accumulator 201. When the working pressure of the gas cylinder group 102 is less than the set value, the gas stored in the gas pressure end of the second piston accumulator 201 needs to be supplemented to the gas cylinder group 102 to increase its working pressure, that is, the volume of the gas pressure end of the second piston accumulator 201 needs to be reduced; correspondingly, the volume of the oil pressure end of the second piston accumulator 201 needs to be increased, that is, the oil pressure end of the second piston accumulator 201 needs to be supplemented with oil.

[0038] It can also be understood that if the traditional pump is used to directly supply oil to the oil pressure end of the second piston accumulator 201, the response of the control valve group and the start of the pump will cause the second piston accumulator 201 to respond to the pressurization of the gas cylinder group 102 with lag. Therefore, in this embodiment, a third piston accumulator 204 is provided. The third piston accumulator 204 is connected to the oil pressure end of the second piston accumulator 201, and can directly output oil to the second piston accumulator 201 when the working pressure of the gas cylinder group 102 is low, thereby effectively improving the air pressure compensation speed of the gas cylinder group 102. Compared with the traditional method, the technical solution of the present application can effectively reduce the pressure fluctuation amplitude of the gas cylinder group 102 during normal operation by setting the second piston accumulator 201 and the third piston accumulator 204, so as to improve the gas supply stability of the gas cylinder group 102.

[0039] It should be known that in order to ensure the pressure compensation speed of the second piston accumulator 201 for the gas cylinder group 102, the oil at the oil pressure end of the second piston accumulator 201 needs to be directly discharged to the oil tank 300, and the function of the third piston accumulator 204 is to supply oil only to the oil pressure end of the second piston accumulator 201. Then when the second piston accumulator 201 is discharging oil, the control valve group needs to isolate the third piston accumulator 204 to prevent the oil in the third piston accumulator 204 from flowing to the second piston accumulator 201. At the same time, when the third piston accumulator 204 replenishes oil to the second piston accumulator 201, the connection between the second piston accumulator 201 and the oil tank 300 also needs to be isolated. There are many specific structures of the control valve group that can realize the above functions. For convenience, one of the structures will be described in detail below.

[0040] In this embodiment, Figure 1As shown, the control valve group includes a first cartridge valve 207, a second cartridge valve 208 and a pilot valve 210. The oil pressure end of the second piston accumulator 201 is connected to the oil tank 300 through the first cartridge valve 207, the third piston accumulator 204 is connected to the second piston accumulator 201 through the second cartridge valve 208, and the pilot valve 210 is connected to the first cartridge valve 207 and the second cartridge valve 208 respectively. When the air pressure of the gas cylinder group 102 is greater than the set value, the pilot valve 210 controls the first cartridge valve 207 to open and controls the second cartridge valve 208 to close. When the air pressure of the gas cylinder group 102 is less than the set value, the pilot valve 210 controls the first cartridge valve 207 to close and controls the second cartridge valve 208 to open.

[0041] It should be known that the specific structures and working principles of the first cartridge valve 207 , the second cartridge valve 208 and the pilot valve 210 are well known to those skilled in the art; for ease of understanding, a detailed description will be given below.

[0042] Specifically, Figure 1 As shown, the input end of the first cartridge valve 207 is connected to the second piston accumulator 201, and the output end of the first cartridge valve 207 is connected to the oil tank 300. The input end of the second cartridge valve 208 is connected to the third piston accumulator 204, and the output end of the second cartridge valve 208 is connected to the input end of the first cartridge valve 207. The pilot valve 210 adopts a two-position four-way valve, including a parallel position and a cross position. The input end of the pilot valve 210 is connected to the third piston accumulator 204, and the output end of the pilot valve 210 is connected to the spring ends of the first cartridge valve 207 and the second cartridge valve 208 respectively.

[0043] When the gas pressure of the gas cylinder group 102 is greater than the set value, the pilot valve 210 is in a cross-position conduction state. At this time, the third piston accumulator 204 is in a self-locking state through the second cartridge valve 208, that is, the third piston accumulator 204 cannot supply oil; at the same time, the spring end of the first cartridge valve 207 is connected to the oil tank 300, that is, there is no additional pressure on the spring end of the first cartridge valve 207, and then the oil discharged from the second piston accumulator 201 can open the first cartridge valve 207 and flow to the oil tank 300.

[0044] When the gas pressure of the gas cylinder group 102 is less than the set value, the pilot valve 210 is in a parallel conduction state. At this time, part of the oil output by the third piston accumulator 204 can flow to the spring end of the first cartridge valve 207 to lock the first cartridge valve 207; at the same time, the spring end of the second cartridge valve 208 is connected to the oil tank 300, that is, there is no additional pressure on the spring end of the second cartridge valve 208, and then the oil output by the third piston accumulator 204 can open the second cartridge valve 208 and flow to the second piston accumulator 201.

[0045] In this embodiment, Figure 1 As shown, the control valve group also includes a servo valve 206, and the oil pressure end of the second piston accumulator 201 is connected to the first cartridge valve 207 and the second cartridge valve 208 respectively through the servo valve 206. Thus, the air pressure fluctuation of the gas cylinder group 102 is regulated by controlling the opening of the servo valve 206.

[0046] It is understandable that the opening of the first cartridge valve 207 and the second cartridge valve 208 cannot be controlled, so in the initial stage of the second piston accumulator 201 discharging oil and the third piston accumulator 204 supplying oil, the action response of the second piston accumulator 201 will be overshoot, which may affect the balancing effect of the second piston accumulator 201 on the pressure fluctuation of the gas cylinder group 102. Therefore, in this embodiment, a servo valve 206 is provided, and by controlling the opening of the servo valve 206, the action response degree of the second piston accumulator 201 can be controlled, thereby improving the balancing effect of the second piston accumulator 201 on the pressure fluctuation of the gas cylinder group 102. The specific structure and working principle of the servo valve 206 are well-known technologies for those skilled in the art, so they will not be elaborated in detail here.

[0047] In this embodiment, Figure 1 As shown, the pressure balancing module further includes a third oil pump 211 and a second one-way valve 209. The input end of the third oil pump 211 is connected to the oil tank 300, and the output end of the third oil pump 211 is connected to the oil pressure end of the third piston accumulator 204 through the second one-way valve 209, so that the third piston accumulator 204 is replenished with oil through the third oil pump 211.

[0048] It is understandable that the second piston accumulator 201 directly discharges the oil to the oil tank 300 when discharging oil. As the air pressure balancing process of the second piston accumulator 201 continues, the amount of oil in the oil pressure end of the third piston accumulator 204 gradually decreases, which will affect the air pressure balancing process of the second piston accumulator 201 on the gas cylinder group 102. Therefore, the third oil pump 211 needs to be set in this embodiment to continuously replenish the third piston accumulator 204. In this embodiment, in order to ensure the continuous and stable operation of the pressure balance module, before the flow test of the servo valve to be measured is performed, the second piston accumulator 201 can be replenished with gas until the air pressure end reaches the maximum volume state by inflating the gas cylinder group 102, and the third piston accumulator 204 can be replenished with oil until the oil pressure end reaches the maximum volume state by the third oil pump 211. There are many specific identification methods for the air pressure end of the second piston accumulator 201 and the oil pressure end of the third piston accumulator 204 reaching the maximum volume state. For the convenience of understanding, a detailed description will be given below through one of the specific examples.

[0049] Specifically, Figure 1 As shown, the oil pressure end of the second piston accumulator 201 is installed with a first travel switch 203. When the first travel switch 203 is triggered, the volume of the gas pressure end of the second piston accumulator 201 reaches the maximum; that is, the first travel switch 203 is installed at the port position of the oil pressure end. The gas pressure end of the third piston accumulator 204 is installed with a second travel switch 205. When the second travel switch 205 is triggered, the oil pressure end of the third piston accumulator 204 reaches the maximum volume; that is, the second travel switch 205 is installed at the port position of the gas pressure end. The specific working process of the first travel switch 203 and the second travel switch 205 is a well-known technology for those skilled in the art, so it will not be elaborated in detail here.

[0050] In this embodiment, Figure 1 As shown, the large flow servo valve oil supply test system also includes a controller 400, and the controller 400 is respectively connected to the servo valve 206, the pilot valve 210, the third oil pump 211, the first stroke switch 203, and the second stroke switch 205 of the control valve group. At the same time, the controller 400 can also be connected to the first pressure sensor 104 and the servo valve test system 106. Therefore, when the flow test of the servo valve to be measured is performed, the controller 400 can receive the pilot oil pressure fed back by the servo valve test system 106 and the oil supply pressure fed back by the first pressure sensor 104; then the corresponding response of the pressure balance module is controlled according to the comparison between the acquired data and the set value. At the same time, the servo valve test system 106 can also send a valve core control signal to the servo valve to be measured.

[0051] Specifically, before the gas cylinder group 102 is not working, the controller 400 can control the servo valve 206 to be in a closed state, and the controller 400 can also control the pilot valve 210 to be in a cross-position conduction state. Then the controller 400 can notify the third oil pump 211 to start, so that the oil output by the third oil pump 211 can flow to the third piston accumulator 204 for oil replenishment, and at this time, the second cartridge valve 208 is in a closed and locked state through part of the oil output by the third oil pump 211. At the same time, the gas cylinder group 102 can be inflated by an additional air compressor (not shown).

[0052] When the first stroke switch 203 corresponding to the second piston accumulator 201 and the second stroke switch 205 corresponding to the third piston accumulator 204 are both triggered, the controller 400 can receive the trigger signal and determine that the second piston accumulator 201 and the third piston accumulator 204 have completed the preparatory work, and then start the air pressure balancing work for the gas cylinder group 102. During the entire process of the second piston accumulator 201 achieving air pressure balancing for the gas cylinder group 102, the controller 400 can determine the actual working air pressure of the gas cylinder group 102 according to the data of the first pressure sensor 104, and control the opening of the servo valve 206 and the conduction position of the pilot valve 210 according to the difference between the actual working air pressure of the gas cylinder group 102 and the set value. At the same time, according to different opening tests, the control signal is sent to the servo valve test system 106, and then the servo valve test system 106 controls the valve core movement of the servo valve to be tested according to the received control signal.

[0053] It should be noted that the specific structure and working principle of the controller 400 are well-known to those skilled in the art, and therefore will not be elaborated in detail herein. The controller 400 controls the opening of the servo valve 206 using a PID control method.

[0054] In this embodiment, when the absolute value of the difference ΔP between the actual air pressure P1 of the gas cylinder group 102 and the set value P is less than the set threshold, the control valve group is in an isolated state; when the absolute value of the difference ΔP between the actual air pressure P1 of the gas cylinder group 102 and the set value P is greater than the set threshold, the control valve group performs pressure balancing work of the gas cylinder group 102.

[0055] It is understandable that if the threshold for starting the gas pressure balance is not set, the gas pressure balance will be started when the actual gas pressure P1 of the gas cylinder group 102 is slightly greater than or less than the set value P, which will cause the gas cylinder group 102 to perform multiple gas pressure balance processes in a short period of time, which will not only increase the amount of data calculation, but also increase the wear of each hydraulic component. It should be known that the specific value of the threshold can be selected according to the actual needs of those skilled in the art.

[0056] Specifically, when the absolute value of the difference ΔP between the actual gas pressure P1 of the gas cylinder group 102 and the set value P is less than the set threshold, the servo valve 206 will be in a closed state, thereby achieving isolation. When the absolute value of ΔP is greater than the set threshold, the control signal U of the servo valve 206 is: .

[0057] Among them, K p Represents the proportionality coefficient, K i represents the integration constant, K d represents the differential constant, and S represents the sampling period.

[0058] The above describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and the specification only describe the principles of the present application. The present application may have various changes and improvements without departing from the spirit and scope of the present application, and these changes and improvements fall within the scope of the present application for which protection is sought. The scope of protection claimed by the present application is defined by the attached claims and their equivalents.

Claims

1. A large flow servo valve oil supply test system, characterized in that: include: tank; A tested valve mounting platform; the tested valve mounting platform is connected to the oil tank and is used to mount the tested valve mounting platform; a first oil pump; an input end of the first oil pump is connected to the oil tank, and an output end of the first oil pump is connected to the measured valve mounting platform, so as to provide a pilot oil supply to the servo valve to be measured; Oil replenishment module; The oil supply module is connected to the tested valve mounting platform to perform an oil supply test on the servo valve to be measured; Measuring module; the measuring module is used to monitor the flow of the oil replenishing module, and then provide feedback on the flow characteristics of the servo valve to be measured; as well as Pressure balance module; The pressure balancing module is connected to the oil replenishing module to balance the pressure lost by the oil replenishing module during the oil supply process.

2. The large flow servo valve oil supply test system according to claim 1, characterized in that: The oil replenishment module comprises: A first piston accumulator; the first piston accumulator is connected to the measured valve mounting platform through an oil pressure end to supply oil to the servo valve to be measured; A gas cylinder group; the gas cylinder group is connected to the gas pressure end of the first piston accumulator to replenish gas to the first piston accumulator; the pressure balancing module is suitable for connecting to the gas cylinder group to balance the gas supply pressure of the gas cylinder group; and A second oil pump; an input end of the second oil pump is connected to the oil tank, and an output end of the second oil pump is connected to the oil pressure end of the first piston accumulator through a first one-way valve.

3. The large flow servo valve oil supply test system as claimed in claim 2, characterized in that: The measurement module comprises: A displacement measuring unit; the displacement measuring unit is used to collect piston movement data of the first piston accumulator; and A servo valve testing system; the servo valve testing system is signal-connected to the displacement measuring unit to receive data collected by the displacement measuring unit, and then calculates the current flow rate passing through the servo valve to be measured based on the piston diameter of the first piston accumulator.

4. The large flow servo valve oil supply test system as claimed in claim 2, characterized in that: The output end of the first oil pump is connected in parallel with: Diaphragm accumulator; the diaphragm accumulator is used to stabilize the pilot oil pressure output by the first oil pump to the servo valve to be measured; A relief valve; the relief valve is connected to the oil tank, and the relief valve is suitable for adjusting the pilot oil pressure; and Second pressure sensor: The second pressure sensor is used to display the pilot oil pressure.

5. The large flow servo valve oil supply test system according to any one of claims 2 to 4, characterized in that: The pressure balancing module includes a second piston accumulator, a third piston accumulator and a control valve group; The gas pressure end of the second piston accumulator is connected to the gas cylinder group, and the oil pressure end of the second piston accumulator is connected to the oil pressure end of the third piston accumulator and the oil tank through the control valve group; When the gas pressure of the gas cylinder group is greater than a set value, the second piston accumulator is suitable for returning the oil at the oil pressure end to the oil tank through the control valve group, so that the gas cylinder group replenishes gas and reduces the pressure of the second piston accumulator; When the gas pressure of the gas cylinder group is less than a set value, the third piston accumulator replenishes oil to the oil pressure end of the second piston accumulator through the control valve group, so that the second piston accumulator replenishes gas and increases the pressure to the gas cylinder group.

6. The large flow servo valve oil supply test system as claimed in claim 5, characterized in that: The control valve group comprises: a first cartridge valve; the oil pressure end of the second piston accumulator is connected to the oil tank through the first cartridge valve; a second cartridge valve; the third piston accumulator is connected to the second piston accumulator via the second cartridge valve; and A pilot valve; the pilot valve is connected to the first cartridge valve and the second cartridge valve respectively; When the gas pressure of the gas cylinder group is greater than a set value, the pilot valve controls the first cartridge valve to open and controls the second cartridge valve to close; When the gas pressure of the gas cylinder group is less than a set value, the pilot valve controls the first cartridge valve to close, and controls the second cartridge valve to open.

7. The large flow servo valve oil supply test system as claimed in claim 6, characterized in that: The control valve group further includes a servo valve, and the oil pressure end of the second piston accumulator is connected to the first cartridge valve and the second cartridge valve respectively through the servo valve.

8. The large flow servo valve oil supply test system as claimed in claim 7, characterized in that: When the absolute value of the difference ΔP between the actual gas pressure P1 of the gas cylinder group and the set value P is less than the set threshold, the control valve group is in an isolated state; When the absolute value of the difference ΔP between the actual gas pressure P1 of the gas cylinder group and the set value P is greater than the set threshold, the control valve group performs the pressure balancing work of the gas cylinder group. At this time, the control signal U of the servo valve is: ； Among them, K p Represents the proportionality coefficient, K i represents the integration constant, K d represents the differential constant, and S represents the sampling period.

9. The large flow servo valve oil supply test system as claimed in claim 5, characterized in that: The pressure balance module also includes a third oil pump and a second one-way valve; The input end of the third oil pump is connected to the oil tank, and the output end of the third oil pump is connected to the oil pressure end of the third piston accumulator through the second one-way valve, so that the third piston accumulator is replenished with oil through the third oil pump; The third piston accumulator is suitable for replenishing oil to the oil pressure end to reach the maximum volume through the third oil pump before the second piston accumulator supplies gas to the gas cylinder group.

10. The large flow servo valve oil supply test system as claimed in claim 2, characterized in that: The large flow servo valve oil supply test system also includes a controller, and the oil pressure end of the first piston accumulator is also connected to a first pressure sensor; The controller is respectively connected to the first pressure sensor, the measuring module and the pressure balancing module by signals; the controller controls the pressure balancing module to perform pressure balancing work according to the collected data of the first pressure sensor; The controller controls the servo valve to be measured according to the collected data of the measurement module.

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