Gas-liquid conversion energy type electro-hydraulic servo valve and method

Abstract

The invention discloses a gas-liquid conversion energy type electro-hydraulic servo valve and a method, and belongs to the field of mechanical hydraulic pressure. The device comprises a nozzle baffle servo valve and an independent energy part, the independent energy part comprises an oil suction side one-way valve, an oil tank, a valve element, a feedback transmission rod, a piston, an air bag, an oil outlet side one-way valve and the like, a self-oscillation system is constructed through the valve element, the feedback transmission rod and the piston, and gas energy is converted into hydraulic energy. During working, the valve element and the piston continuously reciprocate, oil is sucked from the oil tank, high-pressure hydraulic oil is pressed into the air bag for energy storage, power is provided for the servo valve, and a special hydraulic oil source is not needed. The problems that an aircraft servo valve is complex in energy supply pipeline, poor in electromagnetic compatibility and not energy-saving are solved, energy saving is achieved while the structure is simplified, and the system is suitable for an aircraft servo mechanism.

Description

Technical Field

[0001] This invention belongs to the field of mechanical hydraulics, specifically relating to a gas-liquid conversion energy type electro-hydraulic servo valve and method. Background Technology

[0002] Electro-hydraulic servo valves are now widely used in various aircraft, primarily in servo mechanism control systems, accounting for more than one-third of the system's functionality and strongly supporting weapon development. Currently, there are two main ways to power servo valves in aircraft: one is through a long pipeline supplied by the aircraft's main pump, which not only increases pipeline weight and complexity but also results in significant pressure loss; the other method involves integrating a motor and pump with the servo valve, with the aircraft's main power supply providing electrical energy to the motor via cable. The motor drives the hydraulic pump to power the servo valve. This method, however, involves high current transmission via cable, posing significant challenges to the aircraft's electromagnetic compatibility. Summary of the Invention

[0003] To address the technical challenges of providing energy to electro-hydraulic servo valves in existing aircraft, such as the complexity and poor electromagnetic compatibility, this invention proposes a gas-liquid conversion energy type electro-hydraulic servo valve and method.

[0004] The technical solution of the present invention is as follows: A gas-liquid conversion energy type electro-hydraulic servo valve, characterized in that it comprises a nozzle-baffle servo valve and an independent energy component; the independent energy component includes: an oil suction side check valve, an oil filter, an oil tank, a valve core, a feedback transmission rod, hinge I, a slider I, a fixed support rod, hinge II, a slider II, a support hinge, a lower spring, a piston, an upper spring, an air bladder, and an oil outlet side check valve; The valve core is slidably installed in the valve core hole of the housing; the piston is slidably installed in the piston hole of the housing, with a lower spring at the lower end, the lower end of which abuts against the housing and the upper end against the lower end face of the piston's lower shoulder; an upper spring is installed at the upper end, the upper end of which abuts against the housing and the lower end against the upper end face of the piston's lower shoulder; the lowest ends of the valve core and piston are rotatably connected to slider I and slider II respectively via hinge I and hinge II; both sliders are mounted on the feedback transmission rod, which is rotatably connected to the fixed support rod mounted on the housing; the oil tank and air bladder are mounted on the housing; the oil suction side check valve, the oil outlet side check valve, and the oil filter are mounted in the housing's channels; the nozzle baffle servo valve is mounted on the housing of the independent energy section; the valve core has four working surfaces that cooperate with the corresponding working surfaces of the housing to open and close the air passage; the control pressure chamber is connected to both ends of the valve core and the piston shoulder through the feedback channel; The upper end of the piston is connected to the oil chamber. The right end of the oil chamber is equipped with an oil suction side check valve and the left end is equipped with an oil outlet side check valve. The oil passage on the left side of the oil outlet side check valve is connected to the air bladder and the cavity Ps. The oil passage on the right side of the oil suction side check valve is connected to the oil filter and the oil tank. The oil tank communicates with the cavity R.

[0005] Furthermore, the cylindricity of the working cylindrical surface of the valve core is 0.001 mm and the roughness is Ra0.1; this ensures smooth movement of the valve core in the valve core hole of the housing, and the valve core surface has good wear resistance and long service life.

[0006] Furthermore, the four working surfaces A, B, C, and D of the valve core have a coplanarity of 0.02 mm with the working surfaces A1, B2, C1, and D1 of the housing, respectively, and a perpendicularity of 0.005 mm to the valve core axis. This ensures that when the valve core moves to a certain position, the opening values ​​of working surfaces A and A1, B and B1, C and C1, and D and D1 are consistent, resulting in good linearity between the output flow rate and the valve core displacement.

[0007] Furthermore, the gap between the lowest support rod portion of the valve core and the housing is 0.003mm to 0.006mm; this ensures smooth movement between the lowest support rod portion of the valve core and the housing with low resistance, and prevents the lower control pressure feedback channel from communicating with the outside of the housing, thus achieving a sealing effect.

[0008] Furthermore, the cylindricity of the two shoulder cylindrical surfaces of the piston is 0.003 mm and the roughness is Ra0.1; the gap between the thin rod portion of the piston and the housing is 0.003 mm to 0.006 mm; this ensures smooth movement of the piston in the piston hole of the housing, and the piston surface has good wear resistance and long service life.

[0009] The gap between the lowest piston support rod and the housing is 0.003mm to 0.006mm; this ensures smooth movement between the lowest piston support rod and the housing with low resistance, and prevents the lower control pressure cavity from communicating with the outside of the housing, thus providing a sealing effect.

[0010] Furthermore, the volume of the airbag is 2 to 3 times the volume of all oil passages; this ensures that the airbag stores sufficient hydraulic oil to meet the maximum operating flow requirements of the nozzle baffle servo valve.

[0011] Furthermore, the oil flow direction of the suction-side check valve and the outlet-side check valve on the left end is from right to left; this ensures that the oil flow direction is from right to left, preventing the oil in the oil chamber from flowing from left to right. The suction-side check valve ensures that the high-pressure oil in the oil chamber will not leak to the right into the oil tank, and the outlet-side check valve ensures that the high-pressure oil in the oil chamber flows unidirectionally to the left into the air bladder, thereby preventing the high-pressure oil in the air bladder from leaking to the right into the oil chamber.

[0012] Furthermore, the diameters of the upper and lower control pressure feedback channels are no greater than 1 / 10 of the valve core, and their lengths and orifice diameters are matched to ensure that the damping ratio of the closed-loop system consisting of the valve core, feedback transmission rod, and piston is no greater than 0.1. The smaller the damping ratio of the closed-loop system, the more unstable it is and the more prone it is to self-excited oscillation.

[0013] Furthermore, the reactive leakage of the nozzle baffle servo valve is no more than 10 mL / min. It can also be replaced with other types of servo valves, but the reactive leakage value must be guaranteed to be no more than 10 mL / min. In this way, the gas-liquid conversion energy type electro-hydraulic servo valve has low reactive leakage, which is beneficial to improving the dynamic response frequency of the servo valve.

[0014] The loads connected to interfaces 1 and 2 are enclosed actuators, preventing oil from being output or leaking externally. This ensures sufficient internal oil in the gas-liquid conversion energy-type electro-hydraulic servo valve, guaranteeing that the valve operates using internal oil.

[0015] The present invention discloses a gas-liquid conversion energy-type electro-hydraulic servo valve as designed above, the working method of which includes the following steps: S1: By configuring the parameters of claims 6 and 7, the valve core, feedback transmission rod, and piston are constructed into a self-excited oscillation system, so that the amplitude of the open loop when the phase lags by 180° is greater than 1, so as to ensure the continuous up-and-down movement of the valve core and piston. S2: When the valve core moves downward, there is an opening between the working side C of the valve core and the working side C1 of the housing, connecting the upper control pressure chamber to the intake chamber. There is also an opening between the working side A of the valve core and the working side A1 of the housing, connecting the lower control pressure chamber to the exhaust chamber. The upper end face of the piston's lower shoulder is subjected to the high pressure of the intake air, and the lower end face is subjected to the low pressure of the exhaust air, pushing the piston downward. S3: The piston moves downwards simultaneously, the oil chamber pressure decreases, causing the suction side check valve to open, and hydraulic oil flows from the oil tank through the oil filter to the oil chamber until the piston moves to the bottom, at which point the suction side check valve closes.

[0016] S4: Simultaneously, when the valve core moves upward, there is an opening between the working side D of the valve core and the working side D1 of the housing, connecting the upper control pressure chamber to the exhaust chamber, and an opening between the working side B of the valve core and the working side B1 of the housing, connecting the lower control pressure chamber to the intake chamber. The lower end face of the piston's lower shoulder is subjected to the high pressure of the intake air, and the upper end face of the lower shoulder is subjected to the low pressure of the exhaust air, pushing the piston upward. S5: The piston moves upward, the oil chamber pressure increases, causing the outlet check valve to open, and the hydraulic oil is forced from the oil chamber through the outlet check valve into the air bladder until the piston stops moving and the outlet check valve closes.

[0017] S6: At this time, the valve core moves downward. Repeat S2 to S6 to fill the air bladder with high-pressure hydraulic oil, providing pressure and flow for the nozzle baffle servo valve to operate.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1) This is the first time that the self-excited oscillation principle has been used to generate input pressure in the field of servo valves. Conventional hydraulic servo valves, hydraulic servo systems, and motor servo systems are designed to avoid self-excited oscillation frequencies as much as possible to prevent self-excited oscillation from generating large amounts of destructive energy that could lead to system failure. However, this gas-liquid conversion energy-type electro-hydraulic servo valve uses the self-excited oscillation principle. During operation, the valve core and piston generate self-excited oscillations with each other, thereby causing the piston to continuously move and push the pressure oil into the air bladder for energy storage.

[0019] 2) A control pressure feedback channel was invented for the first time, which feeds back the load pressure output by the valve core to both ends of the valve core. The feedback force pushes the valve core to achieve a larger opening, thereby achieving a larger load pressure. The load pressure and valve core displacement achieve a positive feedback mode, which innovatively reduces the damping ratio of the valve core control piston closed-loop system and promotes the realization of self-excited oscillation. 3) A novel independent energy source was invented. By simply introducing gas at a certain pressure from the outside, the device can achieve self-excited oscillation, allowing the piston to complete continuous reciprocating motion. It can sustainably draw oil from the tank and push the pressurized oil into the air bladder for energy storage. This innovatively realizes the conversion of pneumatic energy into hydraulic energy. 4) For the first time, an independent energy device is applied to a servo valve, and then to the servo mechanism of an aircraft. This can convert the intake pressure generated by the aircraft's flight speed into hydraulic energy, avoiding the problem of complex hydraulic pipelines and high-current cables in the aircraft, while also bringing energy-saving effects to the aircraft. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of a gas-liquid conversion energy-type electro-hydraulic servo valve according to an embodiment of the present invention; Figure 2 The upper and lower control pressure feedback channels have large or small orifice sizes, corresponding to the open-loop Bode diagram of the independent energy components. Among them, the oil suction side check valve 1, oil filter 2, oil tank 3, valve core 4, feedback transmission rod 5, hinge I 6, slider I 7, fixed support rod 8, hinge II 9, slider II 10, support hinge 11, lower spring 12, piston 13, upper spring 14, air bag 15, oil outlet side check valve 16, and nozzle baffle servo valve 17. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. 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.

[0023] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.

[0024] In the description of this invention, it should be noted that the directions or positional relationships indicated by terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing and simplifying the invention, and should not be construed as limiting the invention. Furthermore, the use of ordinal numbers (e.g., "first and second," etc.) is for distinguishing objects and is not limited to this order, and should not be construed as indicating or implying relative importance.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly, encompassing both direct connection and indirect connection via an intermediate medium. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0026] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited in each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0028] like Figure 1 and 2 As shown, a gas-liquid conversion energy type electro-hydraulic servo valve is designed in the specific implementation process. The electro-hydraulic servo valve includes a traditional nozzle-baffle servo valve 17 and an independent energy part. The independent energy component includes: 1. suction side check valve, 2. oil filter, 3. oil tank, 4. valve core, 5. feedback transmission rod, 6. hinge I, 7. slider I, 8. fixed support rod, 9. hinge II, 10. slider II, 11. support hinge, 12. lower spring, 13. piston, 14. upper spring, 15. air bag, and 16. oil outlet side check valve. The installation relationship is as follows: The valve core 4 is slidably installed in the valve core hole of the housing; the piston 13 is slidably installed in the piston hole of the housing, and a lower spring 12 is provided at the lower end. The lower end of the lower spring 12 abuts against the housing, and the upper end abuts against the lower end face of the lower shoulder of the piston 13. An upper spring 14 is provided at the upper end. The upper end of the upper spring 14 abuts against the housing, and the lower end abuts against the upper end face of the lower shoulder of the piston 13.

[0029] The valve core 4 is provided with hinge I6 at its lowest end. The fixed support rod 8 is fixedly installed on the housing. The fixed support rod 8 is provided with support hinge 11 at its lowest end. The piston 13 is provided with hinge II9 at its lowest end. The slider I7 is rotatably connected to hinge I6 and is slidably installed on the feedback transmission rod 5. The slider II10 is rotatably connected to hinge II9 and is slidably installed on the feedback transmission rod 5. The feedback transmission rod 5 is rotatably connected to support hinge 11.

[0030] The oil tank 3 and air bag 15 are installed on the housing. The oil suction side check valve 1, the oil outlet side check valve 16, and the oil filter 2 are installed in the housing channel. The nozzle baffle servo valve 17 is installed on the housing of the independent energy part. Connection between air passage and oil passage The valve core 4 has four working surfaces A, B, C, and D, and the housing has corresponding working surfaces A1, B2, C1, and D1. Initially, working surfaces A, B, C, and D are aligned with working surfaces A1, B2, C1, and D1, respectively. The upper shoulder of the valve core 4 communicates with the exhaust container, the lower shoulder communicates with the intake cavity, and the upper shoulder communicates with the exhaust cavity. The sliding displacement of working surface A1 with working surface A is used to connect / disconnect the exhaust cavity from the lower control pressure cavity; the sliding displacement of working surface B1 with working surface B is used to connect / disconnect the intake cavity from the lower control pressure cavity; the sliding displacement of working surface C1 with working surface C is used to connect / disconnect the intake cavity from the upper control pressure cavity; and the sliding displacement of working surface D1 with working surface D is used to connect / disconnect the exhaust cavity from the upper control pressure cavity.

[0031] The upper control pressure chamber communicates with the upper end face of the upper shoulder of the valve core 4 through the upper control pressure feedback channel; the lower control pressure chamber communicates with the lower end face of the lower shoulder of the valve core 4 through the lower control pressure feedback channel. This ensures that when the valve core 4 moves upward, the pressure in the upper control pressure chamber decreases and the pressure in the lower control pressure chamber increases. The upper control pressure feedback channel transmits the force on the upper end face of the valve core, making it smaller, and the lower control pressure feedback channel transmits the force on the lower end face of the valve core, making it larger. As a result, the valve core experiences a greater upward force. The upper and lower control pressure feedback channels work together to provide positive feedback, which helps to reduce the damping ratio in the closed-loop system. The upper control pressure chamber is connected to the upper end face of the lower shoulder of piston 13, and the lower control pressure chamber is connected to the lower end face of the lower shoulder of piston 13.

[0032] The lower end face of the upper shoulder of piston 13 is connected to the exhaust chamber through a channel; The upper end of piston 13 is connected to the oil chamber. The right end of the oil chamber is equipped with an oil suction side check valve 1 and the left end is equipped with an oil outlet side check valve 16. The oil passage on the left side of the oil outlet side check valve 16 is connected to the air bladder 15 and the cavity Ps. The oil passage on the right side of the oil suction side check valve 1 is connected to the oil filter 2 and the oil tank 3. The oil tank 3 communicates with the cavity R. Optional implementation methods include: the cylindricity of the working cylindrical surface of the valve core 4 is 0.001 mm and the roughness is Ra0.1; this ensures that the valve core 4 moves smoothly in the valve core hole of the housing, and the valve core 5 has good wear resistance and long service life.

[0033] The working surfaces A, B, C, and D of valve core 4 have a coplanarity of 0.02 mm with the working surfaces A1, B2, C1, and D1 of the housing, respectively, and a perpendicularity of 0.005 mm with the axis of valve core 4. This ensures that when the valve core moves to a certain position, the opening values ​​of working surfaces A and A1, B and B1, C and C1, and D and D1 are consistent, resulting in good linearity between the output flow rate and the valve core displacement.

[0034] The gap between the lowest support rod of valve core 4 and the housing is 0.003mm to 0.006mm; this ensures smooth movement between the lowest support rod of valve core 4 and the housing with low resistance, and prevents the lower control pressure feedback channel from communicating with the outside of the housing, thus achieving a sealing effect.

[0035] The cylindricity of the two shoulder cylindrical surfaces of the piston 13 is 0.003mm and the roughness is Ra0.1; the gap between the thin rod part of the piston 13 and the shell is 0.003mm to 0.006mm; this ensures that the piston 13 moves smoothly in the piston hole of the shell, and the piston 13 has good wear resistance and long service life.

[0036] The gap between the lowest support rod of piston 13 and the housing is 0.003mm to 0.006mm; this ensures smooth movement between the lowest support rod of piston 13 and the housing with low resistance, and prevents the lower control pressure cavity from communicating with the outside of the housing, thus achieving a sealing effect.

[0037] The volume of the airbag 9 is 2 to 3 times the volume of all oil passages; this ensures that the airbag 9 stores sufficient hydraulic oil to meet the maximum flow rate requirements of the nozzle baffle servo valve 17.

[0038] The oil flow direction of the suction-side check valve 1 and the outlet-side check valve 10 on the left is from right to left; this ensures that the oil flow direction is from right to left, and the oil in the oil chamber cannot flow from left to right. The suction-side check valve 1 ensures that the high-pressure oil in the oil chamber will not leak to the right into the oil tank 3, and the outlet-side check valve 16 ensures that the high-pressure oil in the oil chamber flows unidirectionally to the left into the air bladder 15, thereby preventing the high-pressure oil in the air bladder 15 from leaking to the right into the oil chamber.

[0039] The diameters of the upper and lower control pressure feedback channels are no greater than 1 / 10 of the valve core 4. Their lengths and orifice diameters are matched to ensure that the damping ratio of the closed-loop system comprised of the valve core 4, feedback transmission rod 5, and piston 13 is no greater than 0.1. The smaller the damping ratio of the closed-loop system, the more unstable it is and the more prone it is to self-excited oscillations.

[0040] The ratio of the horizontal distance H2 between hinge I6 and supporting hinge 11 and the horizontal distance H1 between hinge II9 and supporting hinge 11 is sufficiently large to ensure that the amplitude margin of the closed-loop system constructed by valve core 4, feedback transmission rod 5, and piston 13 is negative. That is, when the phase lag is 180°, the open-loop amplitude is greater than 1. The larger the ratio, the greater the open-loop channel gain of this closed-loop system. The greater the open-loop access gain, the negative the stability margin becomes. This makes the closed-loop system an unstable system, and when there is pressure at the air inlet, the closed-loop system will self-excite and oscillate.

[0041] The reactive leakage of the nozzle baffle servo valve 11 is no more than 10 mL / min. It can also be replaced with other types of servo valves, but the reactive leakage value must be guaranteed to be no more than 10 mL / min. In this way, the gas-liquid conversion energy electro-hydraulic servo valve has low reactive leakage, which is beneficial to improving the dynamic response frequency of the servo valve.

[0042] The loads connected to interfaces 1 and 2 are enclosed actuators, preventing oil from being output or leaking externally. This ensures sufficient internal oil in the gas-liquid conversion energy-type electro-hydraulic servo valve, guaranteeing that the valve operates using internal oil.

[0043] The working method of the gas-liquid conversion energy-type electro-hydraulic servo valve designed above includes the following steps: S1: By configuring the parameters of claims 6 and 7, the valve core 4, feedback transmission rod 5, and piston 13 are constructed into a self-excited oscillation system, so that the amplitude of the open loop when the phase lags by 180° is greater than 1, so as to ensure the continuous up-and-down movement of the valve core 4 and piston 13. S2: When the valve core 4 moves downward, there is an opening between the working side C of the valve core 4 and the working side C1 of the housing, connecting the upper control pressure chamber to the intake chamber, and an opening between the working side A of the valve core 4 and the working side A1 of the housing, connecting the lower control pressure chamber to the exhaust chamber. The upper end face of the lower shoulder of the piston 13 is subjected to the high pressure of the intake air and the lower end face of the lower shoulder is subjected to the low pressure of the exhaust air, pushing the piston 13 to move downward. S3: Piston 13 moves downwards simultaneously, the oil chamber pressure decreases, causing the suction side check valve 1 to open, and hydraulic oil flows from oil tank 3 through oil filter 2 into the oil chamber until piston 13 moves to the lowest point, at which point the suction side check valve 1 closes.

[0044] S4: Simultaneously, when the valve core 4 moves upward, there is an opening between the working side D of the valve core 4 and the working side D1 of the housing, connecting the upper control pressure chamber to the exhaust chamber, and an opening between the working side B of the valve core 4 and the working side B1 of the housing, connecting the lower control pressure chamber to the intake chamber. The lower end face of the lower shoulder of the piston 13 is subjected to the high pressure of the intake air and the upper end face of the lower shoulder is subjected to the low pressure of the exhaust air, pushing the piston 13 to move upward; S5: As piston 13 moves upward, the pressure in the oil chamber increases, causing the one-way valve 16 on the oil outlet side to open. Hydraulic oil is then forced from the oil chamber through the one-way valve 16 on the oil outlet side into the air bladder 15 until piston 13 stops moving and the one-way valve 10 on the oil outlet side closes.

[0045] S6: At this time, the valve core 4 moves downward. Repeat S2 to S6 to fill the air bladder 15 with high-pressure hydraulic oil, providing pressure and flow for the nozzle baffle servo valve 11 to work.

[0046] Example 1: A gas-liquid conversion energy type electro-hydraulic servo valve, comprising a conventional nozzle-baffle servo valve 17 and an independent energy source; the independent energy source includes an oil suction side check valve 1, an oil filter 2, an oil tank 3, a valve core 4, a feedback transmission rod 5, a hinge I 6, a slider I 7, a fixed support rod 8, a hinge II 9, a slider II 10, a support hinge 11, a lower spring 12, a piston 13, an upper spring 14, an air bladder 15, and an oil outlet side check valve 16; the valve core 4 is slidably installed in the valve core hole of the housing, and the piston 13 is slidably installed in the piston of the housing. Inside the plug hole, a lower spring 12 is provided at the lower end of the piston 13, and an upper spring 14 is provided at the upper end. The two ends of the lower spring 12 abut against the housing and the lower end face of the lower shoulder of the piston 13, respectively. The two ends of the upper spring 14 abut against the housing and the upper end face of the lower shoulder of the piston 13, respectively. The lower end of the valve core 4 is provided with a hinge I6. The fixed support rod 8 is fixed to the housing and has a supporting hinge 11 at its lower end. The lower end of the piston 13 is provided with a hinge II9. The slider I7 is rotatably connected to the hinge I6 and slidably mounted on the feedback transmission rod 5. The slider II10 is rotatably connected to the hinge II9 and slidably mounted on the feedback transmission rod 5. Feedback transmission rod 5 is rotatably connected to support hinge 11; the oil tank 3 and airbag 15 are located in the housing, the oil suction side check valve 1, the oil outlet side check valve 16, and the oil filter 2 are located in the housing channel, and the nozzle baffle servo valve 17 is installed in the housing of the independent energy part; the valve core 4 has 4 working surfaces A, B, C, and D, and the housing has corresponding working surfaces A1, B2, C1, and D1. The valve core 4 opens and closes the exhaust cavity, the air inlet cavity, and the upper and lower control pressure cavities through the sliding displacement of each working surface and the working surface of the housing; the upper and lower control pressure cavities are respectively connected to the valve core 4. The upper end face of the upper shoulder of the core 4, the lower end face of the lower shoulder, and the upper and lower end faces of the lower shoulder of the piston 13 are connected. The lower end face of the upper shoulder of the piston 13 is connected to the exhaust chamber. The upper end of the piston 13 is connected to the oil chamber. The oil chamber is equipped with an oil suction side check valve 1 on the right end and an oil outlet side check valve 16 on the left end. The oil passage on the left side of the oil outlet side check valve 16 is connected to the air bag 15 and the chamber Ps. The oil passage on the right side of the oil suction side check valve 1 is connected to the oil filter 2 and the oil tank 3 in sequence. The oil tank 3 is connected to the chamber R. This servo valve realizes the conversion of pneumatic energy into hydraulic energy through an independent energy part, without the need for a special hydraulic oil source.

[0047] According to claim 1, the gas-liquid conversion energy type electro-hydraulic servo valve is characterized in that the cylindricity of the working cylindrical surface of the valve core 4 is 0.001 mm and the roughness is Ra0.1; the coplanarity of the working surfaces A, B, C, and D of the valve core 4 with the working surfaces A1, B2, C1, and D1 of the housing is 0.02 mm, and the perpendicularity to the axis of the valve core 4 is 0.005 mm; the gap between the lowermost support rod portion of the valve core 4 and the housing is 0.003 mm to 0.006 mm.

[0048] The cylindricity of the two shoulder cylindrical surfaces of the piston 13 is 0.003 mm and the roughness is Ra0.1; the gap between the thin rod part and the lowermost support rod part of the piston 13 and the housing is 0.003 mm to 0.006 mm.

[0049] The volume of the airbag 15 is 2 to 3 times the volume of all the oil passage sections.

[0050] The oil flow direction of both the suction-side check valve 1 and the outlet-side check valve 16 is from right to left.

[0051] The diameters of the upper control pressure feedback channel and the lower control pressure feedback channel are no greater than 1 / 10 of the valve core 4, and through the matching of length and orifice, the damping ratio of the closed-loop system constructed by the valve core 4, the feedback transmission rod 5 and the piston 13 is no greater than 0.1.

[0052] The ratio of the horizontal distance H2 between hinge I6 and supporting hinge 11 to the horizontal distance H1 between hinge II9 and supporting hinge 11 satisfies the following condition: when the closed-loop system phase lags by 180°, the open-loop amplitude is greater than 1, that is, the system amplitude margin is negative.

[0053] The reactive leakage of the nozzle baffle servo valve 17 shall not exceed 10 mL / min, or it may be replaced with another servo valve whose reactive leakage does not exceed 10 mL / min; the loads connected to interfaces 1 and 2 are closed actuators, and oil output and leakage are not allowed.

[0054] The working method of the gas-liquid conversion energy-type electro-hydraulic servo valve designed in this implementation case includes the following steps: S1: By configuring the dimensions of the upper and lower control pressure feedback channels and the ratio of H2 to H1, the valve core 4, feedback transmission rod 5, and piston 13 are constructed into a self-excited oscillation system, ensuring that the open-loop amplitude is greater than 1 when the phase lag is 180°, so that the valve core 4 and piston 13 continuously move up and down; S2: When the valve core 4 moves downward, the upper control pressure chamber is connected to the inlet chamber and the lower control pressure chamber is connected to the exhaust chamber, and the piston 13 is pushed downward by the pressure difference; S3: The downward movement of the piston 13 increases the oil chamber pressure S2: When the piston 13 is lowered, the suction side check valve 1 opens, and hydraulic oil flows from the oil tank 3 into the oil chamber through the oil filter 2. When the piston 13 reaches the lowest point, the check valve closes. S4: When the valve core 4 moves upward, the upper control pressure chamber connects to the exhaust chamber, and the lower control pressure chamber connects to the intake chamber. The piston 13 is pushed upward by the pressure difference. S5: The upward movement of the piston 13 increases the pressure in the oil chamber, and the outlet side check valve 16 opens, allowing hydraulic oil to be forced into the air bladder 15. When the piston 13 stops moving, the check valve closes. S6: Repeat S2 to S5 to fill the air bladder 15 with high-pressure hydraulic oil, providing pressure and flow to the nozzle baffle servo valve 17.

[0055] The above detailed embodiments are a description of the present invention. It should not be considered that the specific embodiments of the present invention are limited to these descriptions. For those skilled in the art, several simple deductions and substitutions can be made without departing from the concept of the present invention, and all of these should be considered to fall within the protection scope of the present invention.

Claims

1. A gas-liquid conversion energy type electro-hydraulic servo valve, characterized in that, It includes a nozzle baffle servo valve and an independent power supply unit; the independent power supply unit includes: suction side check valve, oil filter, oil tank, valve core, feedback transmission rod, hinge I, slider I, fixed support rod, hinge II, slider II, support hinge, lower spring, piston, upper spring, air bladder, and outlet side check valve; The valve core is slidably installed in the valve core hole of the housing; the piston is slidably installed in the piston hole of the housing, with a lower spring at the lower end, the lower end of which abuts against the housing and the upper end against the lower end face of the piston's lower shoulder; an upper spring is installed at the upper end, the upper end of which abuts against the housing and the lower end against the upper end face of the piston's lower shoulder; the lowest ends of the valve core and piston are rotatably connected to slider I and slider II respectively via hinge I and hinge II; both sliders are mounted on the feedback transmission rod, which is rotatably connected to the fixed support rod mounted on the housing; the oil tank and air bladder are mounted on the housing; the oil suction side check valve, the oil outlet side check valve, and the oil filter are mounted in the housing's channels; the nozzle baffle servo valve is mounted on the housing of the independent energy section; the valve core has four working surfaces that cooperate with the corresponding working surfaces of the housing to open and close the air passage; the control pressure chamber is connected to both ends of the valve core and the piston shoulder through the feedback channel; The upper end of the piston is connected to the oil chamber. The right end of the oil chamber is equipped with an oil suction side check valve and the left end is equipped with an oil outlet side check valve. The oil passage on the left side of the oil outlet side check valve is connected to the air bladder and the cavity Ps. The oil passage on the right side of the oil suction side check valve is connected to the oil filter and the oil tank. The oil tank communicates with the cavity R.

2. The gas-liquid conversion energy type electro-hydraulic servo valve as described in claim 1, characterized in that, The cylindricity of the working cylindrical surface of the valve core is 0.001 mm and the roughness is Ra0.

1. The coplanarity of the four working surfaces A, B, C, and D of the valve core with the working surfaces A1, B2, C1, and D1 of the housing is 0.02 mm, and the perpendicularity to the valve core axis is 0.005 mm. The gap between the lowest support rod part of the valve core and the housing is 0.003 mm to 0.006 mm.

3. The gas-liquid conversion energy type electro-hydraulic servo valve as described in claim 1, characterized in that, The cylindricity of the two convex shoulder cylindrical surfaces of the piston is 0.003 mm and the roughness is Ra0.1; the gap between the thin rod portion of the piston and the housing is 0.003 mm to 0.006 mm; the gap between the lowest support rod portion of the piston and the housing is 0.003 mm to 0.006 mm.

4. The gas-liquid conversion energy type electro-hydraulic servo valve as described in claim 1, characterized in that, The volume of the airbag is 2 to 3 times the volume of all oil passage sections.

5. The gas-liquid conversion energy type electro-hydraulic servo valve as described in claim 1, characterized in that, The oil flow direction of the suction side check valve and the outlet side check valve on the left end is from right to left.

6. The gas-liquid conversion energy type electro-hydraulic servo valve as described in claim 1, characterized in that, The diameter of the upper control pressure feedback channel and the lower control pressure feedback channel is no greater than 1 / 10 of the valve core, and the length and orifice are matched to ensure that the damping ratio of the system is no greater than 0.

1.

7. The gas-liquid conversion energy type electro-hydraulic servo valve as described in claim 1, characterized in that, The ratio of the horizontal distance H2 between hinge I and the supporting hinge and the horizontal distance H1 between hinge II and the supporting hinge is large enough to ensure that the closed-loop system amplitude margin is negative, that is, when the phase lag is 180°, the open-loop amplitude is greater than 1.

8. The gas-liquid conversion energy type electro-hydraulic servo valve as described in claim 1, characterized in that, The reactive leakage of the nozzle baffle servo valve shall not exceed 10 mL / min. Other types of servo valves may also be used, but the reactive leakage value must not exceed 10 mL / min. The loads connected to interfaces 1 and 2 are closed actuators, and oil output and leakage are not allowed.

9. The working method of the gas-liquid conversion energy type electro-hydraulic servo valve as described in claim 1, characterized in that: Includes the following steps: S1: Construct the valve core, feedback transmission rod, and piston into a self-excited oscillation system, so that the open-loop amplitude of the system when the phase lags by 180° is greater than 1, so as to ensure the continuous up-and-down movement of the valve core and piston. S2: When the valve core moves downward, there is an opening between the working side C of the valve core and the working side C1 of the housing, so that the upper control pressure chamber is connected to the intake chamber, and there is an opening between the working side A of the valve core and the working side A1 of the housing, so that the lower control pressure chamber is connected to the exhaust chamber; the upper end face of the lower shoulder of the piston is subjected to the high pressure of the intake air and the lower end face of the lower shoulder is subjected to the low pressure of the exhaust air, which pushes the piston to move downward. S3: The piston moves downwards at the same time, the oil chamber pressure decreases, causing the suction side check valve to open, and the hydraulic oil flows from the oil tank through the oil filter to the oil chamber until the piston moves to the bottom and the suction side check valve closes. S4: At the same time, when the valve core moves upward, there is an opening between the working side D of the valve core and the working side D1 of the housing, so that the upper control pressure chamber is connected to the exhaust chamber, and there is an opening between the working side B of the valve core and the working side B1 of the housing, so that the lower control pressure chamber is connected to the intake chamber; the lower end face of the piston's lower shoulder is subjected to the high pressure of the intake air and the upper end face of the lower shoulder is subjected to the low pressure of the exhaust air, which pushes the piston to move upward. S5: The piston moves upward, the oil chamber pressure increases, which causes the oil outlet check valve to open. Hydraulic oil is forced from the oil chamber through the oil outlet check valve into the air bladder until the piston stops moving and the oil outlet check valve closes. S6: At this time, the valve core moves downward; repeat S2 to S6 to fill the air bladder with high-pressure hydraulic oil, providing pressure and flow for the nozzle baffle servo valve to work.

10. The gas-liquid conversion energy type electro-hydraulic servo valve as described in claim 9, characterized in that: The construction process in step S1 includes: The diameters of the upper and lower control pressure feedback channels are configured to reduce the damping ratio of the system. At the same time, the ratio of H2 to H1 is configured to ensure that the open-loop amplitude of the system when the phase lag is 180° is greater than 1 within a wide range of the set intake pressure, so as to ensure that the system is a self-excited oscillation system. As the oscillation time increases, the amplitude of the piston resonance becomes larger and larger. During resonance, the valve core and piston move up and down continuously.

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