Low-noise electro-hydraulic servo valve

Abstract

The invention belongs to the field of mechanical hydraulic pressure, and particularly relates to a low-noise electro-hydraulic servo valve which comprises a torque motor part arranged on a shell, and a hydraulic amplification stage part, a power stage slide valve part, a wave absorbing device and a cavitation oil supplementing part which are arranged in the shell, according to the wave absorbing device, hydraulic pulsation can be filtered in the leather bag, the capillary channels are different in thickness, length and diameter, hydraulic oil pressure pulsation wave crests and wave troughs output from the capillary channels can be offset, and therefore fluctuation of oil supply pressure is reduced. The problem of oil supply pressure fluctuation filtering is innovatively solved, the cavitation oil supplementing device can rapidly capture cavitation and rapidly supplement high-pressure oil, the cavitation existence time is greatly shortened, and the situation that in traditional hydraulic pressure, in order to reduce cavitation, measures such as complex structural design, strong sealing and corrosion-resistant materials are adopted, and the measures are difficult to achieve is avoided.

Description

Technical Field

[0001] The invention belongs to the field of mechanical hydraulics, and in particular relates to a low-noise electro-hydraulic servo valve. Background Art

[0002] At present, electro-hydraulic servo valves are widely used in many important fields such as advanced civil aircraft, steel, power generation, etc. They are mainly used in servo mechanism control systems. Their functions account for more than 1 / 3 of the system, which strongly supports the development of weapons. At present, the requirements of hydraulic servo systems are getting higher and higher, and the operating conditions are getting more and more severe. If there are high-frequency pulsation components in the system or in the external environment, the servo valve will be stimulated to resonate at high frequency. When the frequency is high and the amplitude is large, the servo valve will scream, which is commonly known as howling in the industry. If the howling continues for a short time, the spring tube will fatigue and break, causing fatal failure to the hydraulic system. At present, the hydraulic system in the industry can suppress the servo valve from howling in certain occasions, but it is impossible to completely prevent the servo valve from howling in all hydraulic systems, which brings hidden dangers of failure to the hydraulic system.

[0003] Relevant research shows that the high-frequency pulsation and howling of the servo valve are directly related to the transient cavitation formed at the nozzle-baffle. The cavitation causes the baffle to resonate, and the resonance of the baffle and the resonance of the valve core promote each other. Once the howling occurs, it will not stop actively. Summary of the invention

[0004] Technical problem solved by the present invention: In order to solve the shortcomings of the existing servo valves, such as high-frequency pulsation and howling, the present invention proposes a low-noise electro-hydraulic servo valve.

[0005] Technical solution of the present invention

[0006] A low-noise electro-hydraulic servo valve comprises a torque motor part arranged on a housing, and a hydraulic amplification stage part, a power stage slide valve part, a wave elimination device, and a cavitation oil replenishment part arranged in the housing;

[0007] The torque motor part includes an upper magnet, a coil, a permanent magnet, an armature, a lower magnet, a spring tube, and a feedback rod. The permanent magnet is arranged between the upper magnet and the lower magnet, the coil is wound on the armature, the armature and the upper end of the feedback rod are installed on the spring tube, and the lower end of the feedback rod is connected to the power valve core of the power stage slide valve part;

[0008] The hydraulic amplification stage part includes a left nozzle, a baffle, a right nozzle, a left throttle hole component, an oil filter, and a right throttle hole component. The left nozzle and the right nozzle are symmetrically installed in the housing. The baffle is arranged between the left nozzle and the right nozzle. The left throttle hole component and the right throttle hole component are respectively sleeved on the left and right ends of the oil filter. The three parts are installed together in the corresponding oil filter hole of the housing; the left end of the left nozzle and the left end of the left throttle hole component are connected to the left end of the power valve core through the housing oil passage; the right end of the right nozzle and the right end of the right throttle hole component are connected to the right end of the power valve core through the housing oil passage;

[0009] The power-level slide valve part includes a valve sleeve and a power valve core; the power valve core is installed in the valve sleeve, and the two are installed together in the valve sleeve hole of the housing;

[0010] The wave-breaking device comprises an oil inlet component, a bladder, an oil outlet component, a connecting plate, and a capillary pipe. The lower end of the oil inlet component is connected to the housing and communicates with the oil inlet chamber Ps. The upper end of the oil inlet component is connected to the bladder, the upper end of the bladder is connected to the oil outlet component, the upper end of the oil outlet component is connected to the connecting plate, and the upper end of the connecting plate is connected to a plurality of capillary pipes of different lengths and diameters.

[0011] The cavitation oil replenishment part includes a left cavitation collecting nozzle, a left spring, a left oil replenishment valve core, a left oil replenishment nozzle, a right oil replenishment nozzle, a right oil replenishment valve core, a right spring, and a right cavitation collecting nozzle; the left oil replenishment valve core is slidably installed in the left hole of the shell, the left spring is sleeved in the cylinder at the right end of the left oil replenishment valve core, the right side of the left spring presses on the left cavitation collecting nozzle fixed in the left hole, the left cavitation collecting nozzle is a through structure, and the left left side of the left spring presses on the right end surface of the right boss of the left oil replenishment valve core; the left end of the left oil replenishment valve core is connected to the overflow chamber through the oil channel, and the right end is connected to the left cavity of the left oil replenishment nozzle; the right side of the left oil replenishment nozzle is connected to the overflow chamber, the left nozzle chamber and the thin rod chamber of the left oil replenishment valve core are connected through the oil channel, and the opening of the left nozzle chamber and the thin rod chamber of the left oil replenishment valve core is controlled by the displacement of the left oil replenishment valve core; the left oil replenishment The lower side of the nozzle is connected to the thin rod cavity of the left oil replenishing valve core through an oil channel, and the upper side is connected to the overflow cavity; the right oil replenishing valve core is slidably installed in the right hole of the shell, the right spring is sleeved in the left end cylinder of the right oil replenishing valve core, the left side of the right spring is pressed on the right cavitation collecting nozzle fixed in the right hole, the right cavitation collecting nozzle is a through structure, and the right side of the right spring is pressed on the left end surface of the left convex shoulder of the right oil replenishing valve core; the right end of the right oil replenishing valve core is connected to the overflow cavity through the oil channel, and the left end is connected to the right side cavity of the right oil replenishing nozzle; the left side of the right oil replenishing nozzle is connected to the overflow cavity, the right nozzle cavity and the thin rod cavity of the right oil replenishing valve core are connected through the oil channel, and the opening of the right nozzle cavity and the thin rod cavity of the right oil replenishing valve core is controlled by the displacement of the right oil replenishing valve core; the lower side of the right oil replenishing nozzle is connected to the thin rod cavity of the right oil replenishing valve core through the oil channel, and the upper side is connected to the overflow cavity.

[0012] Furthermore, the oil passage of the oil inlet chamber Ps1 is connected to the oil passage where the oil filter is installed; the right side of the left nozzle and the left side of the right nozzle are in communication with the overflow chamber.

[0013] Furthermore, the aperture of the oil inlet hole component is larger than the aperture of the oil outlet hole component; the outer diameter of the bladder is 2 / 3 to 3 / 4 of the aperture of the oil inlet channel.

[0014] Furthermore, there are holes of different sizes on the connecting plate, the capillary tube is welded to the connecting plate, and the diameter of the capillary tube is the same as the aperture of the corresponding hole of the connecting plate; the capillary tube is a group of hoses with different lengths and different apertures.

[0015] Furthermore, the cylindricity of the left oil supply valve core and the right oil supply valve core are both 0.001 mm, the roughness is both Ra0.1, and the outer diameter is both 1 / 5 to 1 / 6 of the outer diameter of the power valve core.

[0016] Furthermore, the aperture of the left cavitation collection nozzle is 3 times larger than the aperture of the left oil replenishment nozzle.

[0017] Furthermore, the distance between the left cavitation collection nozzle and the left oil replenishment nozzle is no more than 0.2 mm, and the distance between the left cavitation collection nozzle and the lower side of the left nozzle is no more than 0.5 mm.

[0018] Furthermore, the aperture of the right cavitation collection nozzle is 3 times larger than the aperture of the right oil replenishment nozzle.

[0019] Furthermore, the distance between the right cavitation collection nozzle and the right oil replenishment nozzle is no more than 0.2 mm, and the distance between the right cavitation collection nozzle and the lower side of the right nozzle is no more than 0.5 mm.

[0020] Beneficial Effects

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1) A wave absorbing device was invented, which is small in size and simple in structure. The hydraulic pulsation can be filtered in the bladder. The capillary pipes have different thicknesses, lengths and diameters, which can offset the peaks and troughs of the hydraulic oil pressure pulsation of the output capillary pipes, thereby reducing the fluctuation of the oil supply pressure. The invention innovatively solves the problem of oil supply pressure fluctuation filtering;

[0023] 2) The invention of a cavitation oil replenishment device can quickly capture cavitation and quickly replenish it with high-pressure oil, greatly shortening the existence time of cavitation and avoiding the difficult-to-achieve measures such as complex structural design, strong sealing, and corrosion-resistant materials used in traditional hydraulics to reduce cavitation;

[0024] 3) For the first time, the wave-breaking device is applied to the servo valve, which enables the servo valve to perform high-frequency filtering on the oil inlet pressure pulsation input from the front end. The internal components of the servo valve move smoothly, without generating high-frequency pulsation or fatigue damage, thereby avoiding high-frequency pulsation of the servo valve output flow and pressure and improving output stability.

[0025] 4) The cavitation oil replenishment device is applied to the servo valve for the first time, which can offset the cavitation at the nozzle, thereby avoiding the resonance of the armature assembly and avoiding the occurrence of howling. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of a low-noise electro-hydraulic servo valve according to an embodiment of the present invention;

[0027] Figure 2 is a structural diagram of a wave absorbing device according to an embodiment of the present invention;

[0028] Figure 3It is a structural schematic diagram of a capillary pipe and a connecting plate;

[0029] Among them, 1. upper magnetic conductor, 2. coil, 3. permanent magnet, 4. armature, 5. lower magnetic conductor, 6. baffle, 7. left nozzle, 8. left cavitation collecting nozzle, 9. left spring, 10. left oil supply valve core, 11. left oil supply nozzle, 12. left throttle hole component, 13. oil filter, 14. valve sleeve, 15. power valve core, 16. wave-breaking device, 17. feedback rod, 18. right throttle hole assembly, 19. right oil supply nozzle, 20. right oil supply valve core, 21. right spring, 22. right cavitation collecting nozzle, 23. right nozzle, 24. shell, 25. spring tube; 16A, oil inlet hole component, 16B, bladder, 16C, oil outlet hole component, 16D, connecting plate, 16E, capillary tube. DETAILED DESCRIPTION

[0030] The features and illustrative embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention. The present invention is by no means limited to any specific settings and methods proposed below, but covers any improvements, replacements and modifications of structures, methods, devices without departing from the spirit of the present invention. In the accompanying drawings and the following description, known structures and technologies are not shown to avoid unnecessary ambiguity in the present invention.

[0031] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other, and the embodiments can refer to and quote each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] See also Figure 1 , the present invention provides a low-noise electro-hydraulic servo valve, the electro-hydraulic servo valve comprises a torque motor part, a hydraulic amplifier stage part, a power stage slide valve part, a wave elimination device, and a cavitation oil replenishment part;

[0033] The torque motor part is arranged on the housing 24, including an upper magnet 1, a coil 2, a permanent magnet 3, an armature 4, a lower magnet 5, a spring tube 25, and a feedback rod 17. The permanent magnet 3 is arranged between the upper magnet 1 and the lower magnet 5, the coil 2 is wound on the armature 4, the armature 4 and the upper end of the feedback rod 17 are installed on the spring tube 25, and the lower end of the feedback rod is connected to the power valve core 15 of the power stage slide valve part;

[0034] The hydraulic amplification stage part includes a left nozzle 7, a baffle 6, a right nozzle 23, a left throttle component 12, an oil filter 13, and a right throttle component 18. The left nozzle 7 and the right nozzle 23 are symmetrically mounted on the housing, the baffle 6 is arranged between the left nozzle 7 and the right nozzle 23, the left throttle component 12 and the right throttle component 18 are respectively sleeved on the left and right ends of the oil filter 13, and the three parts are collectively installed in the corresponding oil filter hole of the housing 24;

[0035] The left end of the left nozzle 7, the left end of the left throttle hole component 12 and the left end of the power valve core 15 are connected through the oil passage of the housing 24; the right end of the right nozzle 23, the right end of the right throttle hole component 18 and the right end of the power valve core 15 are connected through the oil passage of the housing 24;

[0036] The power stage slide valve part includes a valve sleeve 14 and a power valve core 15; the power valve core 15 is installed in the valve sleeve 14 and is installed in the valve sleeve hole of the housing 24 together;

[0037] The wave absorbing device includes an oil inlet hole component 16A, a bladder 16B, an oil outlet hole component 16C, a connecting plate 16D, and a capillary tube 16E. The lower end of the oil inlet hole component 16A is connected to the housing 24 and communicates with the oil inlet chamber Ps. The upper end of the oil inlet hole component 16A is connected to the bladder 16B. The upper end of the bladder 16B is connected to the oil outlet hole component 16C. The upper end of the oil outlet hole component 16C is connected to the connecting plate 16D. The upper end of the connecting plate 16D is connected to a plurality of capillary tubes 16E with different lengths and diameters.

[0038] The cavitation oil replenishment part includes a left cavitation collection nozzle 8, a left spring 9, a left oil replenishment valve core 10, a left oil replenishment nozzle 11, a right oil replenishment nozzle 19, a right oil replenishment valve core 20, a right spring 21, and a right cavitation collection nozzle 22;

[0039] The left oil replenishing valve core 10 is slidably installed in the left hole of the housing 24, the left spring 9 is sleeved in the right end cylinder of the left oil replenishing valve core 10, the right side of the left spring 9 presses on the left cavitation collecting nozzle 8 fixed in the left hole, the left cavitation collecting nozzle 8 is a through structure, and the left side of the left spring 9 presses on the right end surface of the right convex shoulder of the left oil replenishing valve core 10; the left end of the left oil replenishing valve core 10 is connected to the overflow chamber through the oil channel, and the right end is connected to the left cavity of the left oil replenishing nozzle 11; the right side of the left oil replenishing nozzle 11 is connected to the overflow chamber, and the left nozzle chamber and the thin rod chamber of the left oil replenishing valve core 10 are connected through the oil channel, and the opening of the left nozzle chamber and the thin rod chamber of the left oil replenishing valve core 10 is controlled by the displacement of the left oil replenishing valve core 10; the lower side of the left oil replenishing nozzle 11 is connected to the thin rod chamber of the left oil replenishing valve core 10 through the oil channel, and the upper side is connected to the overflow chamber;

[0040] The right oil replenishment valve core 20 is slidably installed in the right hole of the housing 24, the right spring 21 is sleeved in the left end cylinder of the right oil replenishment valve core 20, the left side of the right spring 21 presses on the right cavitation collection nozzle 22 fixed in the right hole, the right cavitation collection nozzle 22 is a through structure, and the right side of the right spring 21 presses on the left end surface of the left convex shoulder of the right oil replenishment valve core 20; the right end of the right oil replenishment valve core 20 is connected to the overflow cavity through the oil channel, and the left end is connected to the right side cavity of the right oil replenishment nozzle 19; the right oil replenishment valve core 20 is connected to the overflow cavity through the oil channel, and the left end is connected to the right side cavity of the right oil replenishment nozzle 19; The left side of the nozzle 19 is connected to the overflow chamber, and the right nozzle chamber is connected to the thin rod chamber of the right oil replenishment valve core 20 through an oil channel, and the opening of the right nozzle chamber and the thin rod chamber of the right oil replenishment valve core 20 is controlled by the displacement of the right oil replenishment valve core 20; the lower side of the right oil replenishment nozzle 19 is connected to the thin rod chamber of the right oil replenishment valve core 20 through an oil channel, and the upper side is connected to the overflow chamber; the oil channel of the oil inlet chamber Ps1 is connected to the oil channel where the oil filter 13 is installed; the right side of the left nozzle 7 and the left side of the right nozzle 23 are in communication with the overflow chamber.

[0041] In the present invention, the aperture of the oil inlet hole component 16A is larger than the aperture of the oil outlet hole component 16C; this allows a certain pressure to be retained inside the bladder 16B, allowing the bladder 16B to absorb certain pressure fluctuations.

[0042] The outer diameter of the bladder 16B is 2 / 3 to 3 / 4 of the diameter of the oil inlet passage; thus, when the bladder 16B expands under pressure, the oil inlet passage will not restrict the deformation of the bladder 16B.

[0043] There are holes of different sizes on the connecting plate 16D, and the capillary tube 16E is welded to the connecting plate 16D, and the diameter of the capillary tube 16E is the same as the diameter of the corresponding hole of the connecting plate 16D; the capillary tube 16E is a group of hoses with different lengths and different diameters. In this way, the phase of the hydraulic oil pulsation from each capillary tube 16E is delayed differently, and the amplitude is attenuated, and the peaks and troughs of the output multiple pulsating pressure waves interfere with each other and offset each other, forming filtering.

[0044] In the present invention, the cylindricity of the left oil replenishment valve core 10 and the right oil replenishment valve core 20 are both 0.001mm and the roughness is Ra0.1; this ensures that the left oil replenishment valve core 10 moves smoothly in the left hole of the housing 22, and the valve core has good wear resistance and long service life.

[0045] The outer diameters are 1 / 5 to 1 / 6 of the outer diameter of the power valve core 15, ensuring that the left oil replenishment valve core 10 and the right oil replenishment valve core 20 can be driven quickly with a very small flow rate, and the movement speed is fast, which is conducive to quickly replenishing cavitation.

[0046] The aperture of the left cavitation collection nozzle 8 is 3 times larger than that of the left oil replenishment nozzle 11, and the aperture of the right cavitation collection nozzle 22 is 3 times larger than that of the right oil replenishment nozzle 19; this ensures that the left cavitation collection nozzle 8 and the right cavitation collection nozzle 22 can collect cavitations more efficiently, and the left oil replenishment nozzle 11 and the right oil replenishment nozzle 19 can accurately and quickly replenish the pressure of the cavitations.

[0047] The distance between the left cavitation collection nozzle 8 and the left oil replenishment nozzle 11 is not greater than 0.2 mm, and the distance between the right cavitation collection nozzle 22 and the right oil replenishment nozzle 19 is not greater than 0.2 mm; in this way, after the left oil replenishment nozzle 11 and the right oil replenishment nozzle 19 replenish pressure to eliminate cavitation, the left cavitation collection nozzle 8 and the right cavitation collection nozzle 22 can quickly accept the changes in cavitation, avoiding unnecessary oil replenishment in the cavitation oil replenishment part.

[0048] The distance between the left cavitation collection nozzle 8 and the lower side of the left nozzle 7 is no more than 0.5 mm, and the distance between the right cavitation collection nozzle 22 and the lower side of the right nozzle 23 is no more than 0.5 mm; this ensures that the left cavitation collection nozzle 8 and the right cavitation collection nozzle 22 can collect cavitations more efficiently.

[0049] The low-noise electro-hydraulic servo valve of the present invention has the following working principle: the hydraulic pump servo valve inputs the oil supply pressure Ps, and the high-frequency pulsation in the oil supply pressure is fully filtered by the wave-breaking device, so as to form a stable pressure supply to the hydraulic amplifier stage part and the power stage slide valve part. When the coil 2 inputs a positive current, the armature 4 is acted upon by the electromagnetic force, and moves counterclockwise around the rotation center of the spring tube 25, driving the baffle 6 to deflect to the right, thereby reducing the pressure on the left side of the left nozzle 7 and increasing the pressure on the right side of the right nozzle 23. The cavitation oil replenishment part compensates for the cavitation, and the pressure fluctuations on the left side of the left nozzle 7 and the right side of the right nozzle 23 are reduced. The stable hydraulic pressure acts on the left and right end surfaces of the power valve core 15, and the power valve core 15 moves to the left, and the high-pressure oil outputs the pressure and flow through the opening of the power valve core 15 and the valve sleeve 16. In addition, the displacement of the power valve core 15 transmits the force to the spring tube 25 through the feedback rod 18, and finally realizes the force balance, and the valve core stops at the specified position. Similarly, when the coil 2 inputs a negative current, the movement direction of the internal parts of the servo valve is opposite to the above. This servo valve also includes a wave elimination device and a cavitation oil replenishment part. Its working process is as follows:

[0050] The working principle of the wave-breaking device is as follows: the hydraulic oil with high-frequency pulsation flows through the wave-breaking device and then passes through four filters. The specific process is as follows:

[0051] ①, the throttle hole of the oil inlet component 16A enters the bladder 16B and passes through the first filter;

[0052] ② The skin bag 16B will be deformed when it is under pressure. The skin bag 16B is made of rubber and has a very low response frequency. The high-frequency pulsation component can be filtered for the second time.

[0053] ③, the hydraulic oil enters the throttle hole of the oil outlet component 16C, and the high-frequency pulsation component can be filtered for the third time;

[0054] ④. The hydraulic oil enters the small hole of the connecting plate 16D and then enters the capillary 16E. The capillary 16E is a group of thin-walled hoses with different lengths. The phase of the hydraulic oil pulsation coming out of each capillary 16E is delayed differently and the amplitude is attenuated. The peaks and troughs of the multiple pulsating pressure waves outputted finally interfere with and offset each other, forming the fourth filtering.

[0055] Ultimately, the pulsating pressure oil is transformed into a stable pressure oil, the servo valve works smoothly, and the noise is reduced.

[0056] Among them, the working principle of cavitation oil replenishment is:

[0057] When the left nozzle 7 sprays high-speed oil or the oil carries a certain amount of gas, cavitation is likely to occur near the left nozzle 7. The cavitation is an extremely low negative pressure. At this time, the left cavitation collecting nozzle 8 can capture the negative pressure and introduce the pressure value into the right end of the left oil replenishment valve core 10. The pressure at the left end of the left oil replenishment valve core 10 is much higher than that at the right end. The left oil replenishment valve core 10 moves rapidly to the right, and the left nozzle cavity is connected with the thin rod cavity of the left oil replenishment valve core 10. The hydraulic oil in the left nozzle cavity quickly flows into the left oil replenishment nozzle 11 through the oil channel. The left oil replenishment nozzle 11 sprays high-pressure oil to quickly replenish the cavitation. The cavitation disappears, and the pressure at the right end of the left oil replenishment valve core 10 quickly returns to the overflow cavity pressure. The left oil replenishment valve core 10 quickly returns to its initial position, and the left nozzle cavity is connected with the thin rod cavity of the left oil replenishment valve core 10 and is closed.

[0058] When the right nozzle 23 sprays high-speed oil or oil with a certain amount of gas, cavitation is likely to occur near the right nozzle 23. The cavitation is an extremely low negative pressure. At this time, the right cavitation collecting nozzle 22 can capture the negative pressure and introduce the pressure value into the left end of the right oil replenishment valve core 20. The pressure at the left end of the right oil replenishment valve core 20 is much higher than that at the left end. The right oil replenishment valve core 20 moves rapidly to the left, and the right nozzle cavity is connected with the thin rod cavity of the right oil replenishment valve core 20. The hydraulic oil in the right nozzle cavity quickly flows into the right oil replenishment nozzle 19 through the oil channel. The right oil replenishment nozzle 19 sprays high-pressure oil to quickly replenish the cavitation. The cavitation disappears, and the pressure at the left end of the right oil replenishment valve core 20 quickly returns to the overflow cavity pressure. The right oil replenishment valve core 20 quickly returns to its initial position, and the left nozzle cavity is connected to the thin rod cavity of the right oil replenishment valve core 20 and is closed.

[0059] This process can quickly eliminate the cavitation near the left nozzle 7 and the right nozzle 23, avoid the huge pressure fluctuation and noise caused by the cavitation elimination process, and further avoid the high-frequency oscillation of the baffle. In this way, the pressure transmitted to the power valve core 15 does not contain pulsation components, the power valve core 15 moves stably, and the servo valve howling problem is solved.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the field can easily think of various equivalent modifications or substitutions within the technical scope disclosed by the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A low-noise electro-hydraulic servo valve, characterized in that: It includes a torque motor part arranged on the housing, and a hydraulic amplification stage part, a power stage slide valve part, a wave elimination device, and a cavitation oil replenishment part arranged in the housing; The torque motor part includes an upper magnet, a coil, a permanent magnet, an armature, a lower magnet, a spring tube, and a feedback rod. The permanent magnet is arranged between the upper magnet and the lower magnet, the coil is wound on the armature, the armature and the upper end of the feedback rod are installed on the spring tube, and the lower end of the feedback rod is connected to the power valve core of the power stage slide valve part; The hydraulic amplification stage part includes a left nozzle, a baffle, a right nozzle, a left throttle hole component, an oil filter, and a right throttle hole component. The left nozzle and the right nozzle are symmetrically installed in the housing. The baffle is arranged between the left nozzle and the right nozzle. The left throttle hole component and the right throttle hole component are respectively sleeved on the left and right ends of the oil filter. The three parts are installed together in the corresponding oil filter hole of the housing; the left end of the left nozzle and the left end of the left throttle hole component are connected to the left end of the power valve core through the housing oil passage; the right end of the right nozzle and the right end of the right throttle hole component are connected to the right end of the power valve core through the housing oil passage; The power-level slide valve part includes a valve sleeve and a power valve core; the power valve core is installed in the valve sleeve, and the two are installed together in the valve sleeve hole of the housing; The wave-breaking device comprises an oil inlet component, a bladder, an oil outlet component, a connecting plate, and a capillary pipe. The lower end of the oil inlet component is connected to the housing and communicates with the oil inlet chamber Ps. The upper end of the oil inlet component is connected to the bladder, the upper end of the bladder is connected to the oil outlet component, the upper end of the oil outlet component is connected to the connecting plate, and the upper end of the connecting plate is connected to a plurality of capillary pipes of different lengths and diameters. The cavitation oil replenishment part includes a left cavitation collecting nozzle, a left spring, a left oil replenishment valve core, a left oil replenishment nozzle, a right oil replenishment nozzle, a right oil replenishment valve core, a right spring, and a right cavitation collecting nozzle; the left oil replenishment valve core is slidably installed in the left hole of the shell, the left spring is sleeved in the cylinder at the right end of the left oil replenishment valve core, the right side of the left spring presses on the left cavitation collecting nozzle fixed in the left hole, the left cavitation collecting nozzle is a through structure, and the left left side of the left spring presses on the right end surface of the right boss of the left oil replenishment valve core; the left end of the left oil replenishment valve core is connected to the overflow chamber through the oil channel, and the right end is connected to the left cavity of the left oil replenishment nozzle; the right side of the left oil replenishment nozzle is connected to the overflow chamber, the left nozzle chamber and the thin rod chamber of the left oil replenishment valve core are connected through the oil channel, and the opening of the left nozzle chamber and the thin rod chamber of the left oil replenishment valve core is controlled by the displacement of the left oil replenishment valve core; the left oil replenishment The lower side of the nozzle is connected to the thin rod cavity of the left oil replenishing valve core through an oil channel, and the upper side is connected to the overflow cavity; the right oil replenishing valve core is slidably installed in the right hole of the shell, the right spring is sleeved in the left end cylinder of the right oil replenishing valve core, the left side of the right spring is pressed on the right cavitation collecting nozzle fixed in the right hole, the right cavitation collecting nozzle is a through structure, and the right side of the right spring is pressed on the left end surface of the left convex shoulder of the right oil replenishing valve core; the right end of the right oil replenishing valve core is connected to the overflow cavity through the oil channel, and the left end is connected to the right side cavity of the right oil replenishing nozzle; the left side of the right oil replenishing nozzle is connected to the overflow cavity, the right nozzle cavity and the thin rod cavity of the right oil replenishing valve core are connected through the oil channel, and the opening of the right nozzle cavity and the thin rod cavity of the right oil replenishing valve core is controlled by the displacement of the right oil replenishing valve core; the lower side of the right oil replenishing nozzle is connected to the thin rod cavity of the right oil replenishing valve core through the oil channel, and the upper side is connected to the overflow cavity.

2. A low-noise electro-hydraulic servo valve as claimed in claim 1, characterized in that: The oil passage of the oil inlet chamber Ps1 is connected to the oil passage where the oil filter is installed; the right side of the left nozzle and the left side of the right nozzle are communicated with the overflow chamber.

3. A low-noise electro-hydraulic servo valve as claimed in claim 1, characterized in that: The aperture of the oil inlet hole component is larger than that of the oil outlet hole component; the outer diameter of the bladder is 2 / 3 to 3 / 4 of the aperture of the oil inlet passage.

4. A low-noise electro-hydraulic servo valve as claimed in claim 1, characterized in that: There are holes of different sizes on the connecting plate, the capillary pipe is welded to the connecting plate, and the diameter of the capillary pipe is the same as the aperture of the corresponding hole of the connecting plate; the capillary pipe is a group of hoses with different lengths and different apertures.

5. A low-noise electro-hydraulic servo valve as claimed in claim 1, characterized in that: The cylindricity of the left oil supply valve core and the right oil supply valve core are both 0.001 mm, the roughness is both Ra0.1, and the outer diameter is 1 / 5 to 1 / 6 of the outer diameter of the power valve core.

6. A low-noise electro-hydraulic servo valve as claimed in claim 1, characterized in that: The aperture of the left cavitation collection nozzle is 3 times larger than that of the left oil replenishment nozzle.

7. A low-noise electro-hydraulic servo valve as claimed in claim 6, characterized in that: The distance between the left cavitation collection nozzle and the left oil replenishment nozzle is not greater than 0.2 mm, and the distance between the left cavitation collection nozzle and the lower side of the left nozzle is not greater than 0.5 mm.

8. A low-noise electro-hydraulic servo valve as claimed in claim 1, characterized in that: The aperture of the right cavitation collection nozzle is 3 times larger than that of the right oil replenishment nozzle.

9. A low-noise electro-hydraulic servo valve as claimed in claim 8, characterized in that: The distance between the right cavitation collection nozzle and the right oil supply nozzle is not greater than 0.2 mm, and the distance between the right cavitation collection nozzle and the lower side of the right nozzle is not greater than 0.5 mm.

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