Anti-fatigue valve element, servo valve and valve element production process

Abstract

The invention discloses an anti-fatigue valve element, a servo valve and a valve element production process, and relates to the technical field of electro-hydraulic servo valves.The anti-fatigue valve element comprises a valve element shell and a deflection rod arranged in the valve element shell, one end of the valve element shell is closed to form a closed end, the end, away from the closed end, of the valve element shell is an open end, and the deflection rod is arranged in the valve element shell; a valve core cavity is defined by the closed end and the inner wall of the valve core shell; the deflection rod is arranged in the valve element cavity and fixedly connected with the closed end of the valve element shell, protrusions distributed in a dot matrix mode are arranged on the inner wall of the valve element shell, and the protrusions are contained in the valve element cavity and abut against the deflection rod. The protrusions arranged on the inner wall of the valve element shell abut against the deflection rod to fix the deflection rod in multiple directions, so that the deflection rod is prevented from moving in the valve element cavity in the radial direction, the possibility of bending fatigue of the deflection rod is reduced, and the anti-fatigue performance is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of electro-hydraulic servo valves, and in particular to an anti-fatigue valve core, a servo valve and a valve core production process. Background Art

[0002] Electro-hydraulic servovalves are widely used in aerospace, weapons and equipment, energy and electricity, material forming and testing and other fields. With their superior control and amplification performance, they empower various mechanical systems such as aircraft, energy equipment, forming machinery and equipment, and testing equipment.

[0003] Common types of electro-hydraulic servo valves include direct-drive servo valves, two-stage (three-stage) spray-block servo valves, two-stage (three-stage) jet servo valves, etc. Among them, direct-drive servo valves have the advantages of small leakage and high response efficiency because they do not require a pilot stage, but they are limited by the processing technology of valve components, such as: the outer shell flow channel is formed by cross drilling, the valve core shape is processed by subtractive material, etc. Compared with two-stage valves, they have disadvantages such as smaller flow per unit mass and larger volume.

[0004] In recent years, the continuous innovation of additive manufacturing technology and motor control technology has made the direct-drive servo valve have advantages such as larger flow per unit mass, more compact design, and faster frequency response. However, while technological innovation has brought advantages to the direct-drive servo valve, there are still some shortcomings that need to be improved urgently: the motor currently used is a rotary motor, which is generally composed of a motor rotor with an integrated crankshaft connected to the circular ring at the end of the valve core deflection rod. The eccentric crankshaft drives the circular ring to move during the rotation process. At this time, the circular ring movement has both the axial component of the valve core sliding and the component of the vertical sliding axis. The component of the vertical sliding axis will cause the valve core deflection rod to bend in the valve core cavity. According to the simulation results and the actual valve core life test, it can be known that the connection between the bottom of the valve core deflection rod and the bottom of the valve core cavity is the most severely bent, that is, it is most prone to fatigue failure. Therefore, how to solve the problem of fatigue failure caused by the bending of the valve core end of the servo valve needs to be solved urgently. Summary of the invention

[0005] The main purpose of the present invention is to propose an anti-fatigue valve core, a servo valve and a valve core production process, aiming to improve the problem of fatigue failure of the valve core of the servo valve during operation and enhance the service life of the transmission system.

[0006] To achieve the above-mentioned purpose, the present invention proposes an anti-fatigue valve core, which includes a valve core housing, a deflection rod arranged inside the valve core housing, one end of the valve core housing is closed to form a closed end, and the end away from the closed end is an open end, and the closed end and the inner wall of the valve core housing define a valve core cavity; the deflection rod is arranged in the valve core cavity and fixedly connected to the closed end of the valve core housing, and the inner wall of the valve core housing is provided with protrusions arranged in a dot matrix, the protrusions are accommodated in the valve core cavity and resist the deflection rod. The protrusions arranged on the inner wall of the valve core housing support the deflection rod to form a multi-directional fixation of the deflection rod, thereby preventing the deflection rod from moving radially in the valve core cavity, thereby reducing the possibility of bending fatigue of the deflection rod and greatly improving the anti-fatigue performance; and the protrusions can be arranged in a dot matrix as much as possible to make the support of the deflection rod more stable, and through this regular arrangement, the possibility of wear or breakage between the deflection rod and the protrusions is reduced, making the support point of the deflection rod more professional, further improving the fatigue resistance of the valve core.

[0007] In one embodiment, the protrusions are arranged in a dot matrix axially around the inner wall of the valve core housing from the closed end to the open end, and the coverage length is greater than or equal to three quarters of the length of the valve core cavity. Since the open end is closer to the connection end of the deflection rod and the servo motor, the bending force on the deflection rod at the closed end is the greatest, and fatigue failure is most likely to occur here. Therefore, the protrusions are arranged one by one from the closed end to the open end in the valve core cavity, which can give priority to reducing the fatigue value of the connection between the deflection rod and the valve core housing to a greater extent. At the same time, the larger the setting area of ​​the protrusions, the less likely the deflection rod is to deform, and the more stably it is fixed, thereby better improving the anti-fatigue degree of the valve core.

[0008] In one embodiment, the cross-sectional area of ​​the valve core cavity at the coverage range of the protrusion corresponding to the valve core cavity is consistent or changes regularly in the axial extension direction; the arrangement density of the protrusion along the axial direction of the valve core cavity is consistent or changes regularly. The valve core cavity corresponds to the place where the protrusion is arranged, the cross-sectional area of ​​the valve core cavity is consistent or changes regularly, and the arrangement density of the protrusion is consistent or changes regularly in order to make the molding process more convenient when molding the valve core cavity and the protrusion, thereby ensuring that the protrusion has a guaranteed degree of fixation on the deflection rod, improving the process production efficiency while ensuring sufficient anti-fatigue performance.

[0009] In one embodiment, a gas flow channel is provided at the closed end of the valve core cavity, and the inner wall of the gas flow channel is a topological curved surface structure. By further topologically optimizing the inner wall of the gas flow channel, the best curved surface design structure is found, and the gas in the valve core cavity is guided to reduce the flow blockage of the gas in the valve core cavity during operation, thereby affecting the accuracy of the servo valve.

[0010] The present invention also proposes a servo valve, which includes a valve body, a valve body shell, an anti-fatigue valve core and a servo motor arranged in the valve body shell, at least a part of the servo motor is arranged in the valve body, the anti-fatigue valve core includes a valve core housing, a deflection rod arranged inside the valve core housing, the valve core housing is hollow to form a valve core cavity, the deflection rod is arranged in the valve core cavity, one end of the deflection rod is connected to the valve core housing, and the other end extends out of the valve core cavity for use with the servo motor; the inner wall of the valve core housing is provided with a dot matrix-arranged protrusion, the protrusion is accommodated in the valve core cavity and abuts the deflection rod, when the deflection rod moves with the servo motor, the protrusion abuts the deflection rod to prevent the deflection rod from radially displacing in the valve core cavity. Specifically, a servo valve in this embodiment adopts all the technical solutions of the anti-fatigue valve core in the above-mentioned embodiment, and therefore has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiment, which will not be repeated here.

[0011] In one embodiment, the servo motor includes a mover, which is disposed inside the valve body and fixedly connected or integrally formed with the deflection rod of the valve core. Specifically, the mover is fixedly connected or integrally formed with the deflection rod of the valve core. This design simplifies the transmission structure of the servo motor and the valve core, avoids direct contact and friction failure between the rotor of the servo motor and the end face of the deflection rod, eliminates the process of fine machining of the end of the deflection rod, and further improves the overall life of the valve core and the stability of long-term operation.

[0012] The present invention also proposes a valve core production process, including the following steps: obtaining a three-dimensional model of an anti-fatigue valve core, and obtaining corresponding data information based on the three-dimensional model; providing raw materials to be stacked layer by layer from bottom to top based on the data information of the anti-fatigue valve core, and solidifying and connecting the inside of the cross-sectional profiles of adjacent layers to obtain an initial product; performing preset post-processing on the initial product to obtain the required product. This production process is an additive manufacturing process, which obtains a valve core that meets the requirements by stacking, solidifying, connecting and post-processing pre-selected raw materials. The processing is simple and the production is convenient. The specifically produced valve core adopts all the technical solutions of the anti-fatigue valve core of the above-mentioned embodiment, and therefore has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiment, which will not be described one by one here. The technical solution of the present invention adds dot-matrix-arranged protrusions in the valve core cavity and adds a topological structure design at the end of the valve core cavity, so that the valve core is less affected by disturbances or even no longer disturbed, thereby improving the overall service life of the valve core and long-term operating stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0014] Figure 1 A schematic diagram of the three-dimensional structure of an embodiment of an anti-fatigue valve core provided by the present invention; Figure 2 A cross-sectional view of another embodiment of the anti-fatigue valve core provided by the present invention; Figure 3 A schematic diagram of the three-dimensional structure of a servo valve according to an embodiment of the present invention.

[0015] Figure 4 A partial structural cross section of another embodiment of the servo valve provided by the present invention Figure 1 ; Figure 5 A partial structural cross section of another embodiment of the servo valve provided by the present invention Figure 2 ; Figure 6 A flow chart of the steps of the valve core production process provided by the present invention; Figure 7 This is a flow chart of step S3 in the valve core production process provided by the present invention.

[0016] Description of Figure Numbers: 100, anti-fatigue valve core; 11, valve core housing; 12, deflection rod; 13, valve core cavity; 14, protrusion; 111, closed end; 112, open end; 131, gas flow channel; 200, servo valve; 21, valve body; 22, servo motor; 211. Valve body housing; 221. Movers.

[0017] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] It should be noted that if there are directional indications (such as up, down, left, right, front, back, etc.) involved in the embodiments of the present invention, the directional indication is only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly. Unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, and it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0020] In addition, if there are descriptions of "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features. Moreover, the terms "include", "comprise", or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article, or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article, or device. In the absence of further restrictions, the elements defined by the sentence "include one..." do not exclude the presence of other identical elements in the process, method, article, or device including the elements. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel schemes, taking "A and / or B" as an example, including scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0021] Common types of electro-hydraulic servo valves include direct-drive servo valves, two-stage (three-stage) spray-block servo valves, and two-stage (three-stage) jet servo valves. Among them, direct-drive servo valves have the advantages of small leakage and high response efficiency because they do not require a pilot stage. However, they are limited by the processing technology of valve components. At present, the motor used in direct-drive servo valves is a rotary motor. Generally, the motor rotor with an integrated crankshaft of the rotary motor is connected to the circular ring at the end of the valve core deflection rod. The eccentric crankshaft drives the circular ring to move during the rotation process. At this time, the circular ring movement has both the axial component of the valve core sliding and the component of the vertical sliding axis. The component of the vertical sliding axis will cause the valve core deflection rod to bend in the valve core cavity. According to the simulation results and the actual valve core life test, it can be known that the connection between the bottom of the valve core deflection rod and the bottom of the valve core cavity is the most severely bent, that is, fatigue failure is most likely to occur here; lengthening the deflection rod can reduce the bending angle of the bottom of the deflection rod, but it will also cause the valve core design of most such direct-drive servo valves to be longer overall.

[0022] Please combine Figure 1 and Figure 2 In order to improve the anti-fatigue ability of the valve core, the present invention proposes an anti-fatigue valve core 100. The anti-fatigue valve core 100 includes a valve core housing 11, a deflection rod 12 arranged inside the valve core housing 11, one end of the valve core housing 11 is closed to form a closed end 111, and the end away from the closed end 111 is an open end 112, and the closed end 111 and the inner wall of the valve core housing 11 define a valve core cavity 13; the deflection rod 12 is arranged in the valve core cavity 13 and is fixedly connected to the closed end 111 of the valve core housing 11, and the inner wall of the valve core housing 11 is provided with protrusions 14 arranged in a dot matrix, and the protrusions 14 are accommodated in the valve core cavity 13 and resist the deflection rod 12.

[0023] It should be noted that the protrusion 14 arranged on the inner wall of the valve core housing 11 forms a multi-directional fixation for the deflection rod 12 by abutting against the deflection rod 12, thereby preventing the deflection rod 12 from moving radially in the valve core cavity 13, thereby reducing the possibility of bending fatigue of the deflection rod 12 and greatly improving the anti-fatigue performance.

[0024] Specifically, in one embodiment of the present invention, the lattice arrangement of the protrusions 14 includes at least one or more combinations of three-periodic minimal surface lattices, or one or more combinations of various lattice forms in three-periodic minimal surface lattices and general lattices (also called truss lattices).

[0025] It should be noted that the Triply Periodic Minimal Surface (TPMS) lattice structure is composed of surfaces with the smallest area and zero average curvature that meet specific constraints and are arranged periodically in space. Compared with conventional truss lattice structures, the TPMS lattice structure has uniform stress distribution, balanced load-bearing capacity in all directions, and long fatigue life when subjected to force, so it has a broader application prospect.

[0026] Specifically, the forms of three-periodic minimal surface lattices include but are not limited to Neovius lattices, Split Point lattices (split point lattices), Diamond lattices (two face-centered cubic lattices), Schwartz lattices (micro-nano lattices), Gyroid lattices (spiral minimal surface lattices) and Lidinoid lattices; the forms of general lattices include but are not limited to simple cubic lattices, body-centered cubic lattices, face-centered cubic lattices, columnar lattices, Kelvin lattices, triangular honeycomb lattices, hexagonal honeycomb lattices, hexagonal prism Laves lattices, quadrilateral honeycomb lattices, hexagonal prism sharp edge lattices, ten-sided vertex centroid lattices and simple cubic foam lattices, etc.; Preferably, in a specific embodiment of the present invention, a composite dot matrix combining a Split Point dot matrix and a triangular honeycomb dot matrix is ​​used, and the projections 14 are arranged on the inner wall of the valve core housing 11 based on the composite dot matrix.

[0027] In one embodiment of the present invention, the protrusion 14 is a divergent cellular structure with the lattice point on the valve core housing 11 as the starting point, and each point of the cellular structure is connected by a truss rod or a three-periodic minimal surface, wherein the truss diameter of the protrusion 14 or the width of the three-periodic minimal surface is 0.1 mm-10 mm, and the unit cell side length of the lattice is 0.2 mm-100 mm.

[0028] It should be noted that the lattice is a periodic spatial structure, which is composed of a large number of identical crystal cells periodically combined, and the side length of a single cell is the side length of each crystal cell in the lattice; each point on each crystal cell of the protrusion 14 is connected by a three-periodic minimal surface, or connected to each other by a wire rod, and the connecting wire rod is also called a truss rod or a wire rod.

[0029] Optionally, for different lattice combinations, the truss rod diameter or the three-periodic minimal surface width of the protrusion 14 can be 0.1 mm, 0.4 mm, 6 mm, or 10 mm; the unit cell side length of the lattice can be 0.2 mm, 2 mm, 34 mm, 80 mm, or 100 mm.

[0030] Preferably, in an embodiment of the present invention, the valve core cavity 13 is filled with a composite lattice combining a SplitPoint lattice with a unit cell side length of 2 mm and a triangular honeycomb lattice, and the thickness of the small curved surface of the lattice is 0.4 mm.

[0031] It can be understood that the dot matrix arrangement of the protrusions 14 can arrange as many protrusions 14 as possible, making the support for the deflection rod 12 as stable as possible, and through this regular arrangement, the possibility of wear or breakage between the deflection rod 12 and the protrusions 14 is reduced, making the support point of the deflection rod 12 more professional, further improving the fatigue resistance of the valve core.

[0032] In one embodiment of the present invention, the protrusions 14 of the anti-fatigue valve core 100 are arranged in an axially surrounding matrix on the inner wall of the valve core housing 11 from the closed end 111 to the open end 112 , and the covering length is greater than or equal to three quarters of the length of the valve core cavity 13 .

[0033] It should be noted that the arrangement of the protrusions 14 in the anti-fatigue valve core 100 on the inner wall of the valve core housing 11 can be spirally arranged, symmetrically arranged, or randomly arranged. The specific arrangement is affected by the combination type of the dot matrix and is not specifically limited here. The axial covering length of the protrusion 14 on the inner wall of the valve core housing 11 is at least three quarters of the length of the valve core cavity 13. Since the closed end 111 of the valve core housing 11 is relatively thin, when the length of the valve core housing 11 is greater than or equal to the order of centimeters, the axial length of the valve core housing 11 occupied by the thickness of the closed end 111 can be relatively ignored, and the axial length of the valve core cavity 13 is approximately equal to the axial length of the valve core housing 11.

[0034] In addition, since the open end 112 is closer to the connection end between the flexure rod 12 and the servo motor 22, the bending force on the flexure rod 12 at the closed end 111 is the greatest, and fatigue failure is most likely to occur here. Therefore, the protrusions 14 are arranged one by one from the closed end 111 to the open end 112 in the valve core cavity 13, which can prioritize reducing the fatigue value of the connection between the flexure rod 12 and the valve core housing 11 to a greater extent. At the same time, the larger the setting area of ​​the protrusion 14, the smaller the possibility of deformation of the flexure rod 12, and the more stably it is fixed, thereby better improving the fatigue resistance of the valve core.

[0035] It should be noted that there is no restriction on the shape and structure of the valve core housing 11, as long as the valve core cavity 13 is opened and used to support the inner wall of the valve body of the servo valve. Specifically, in one embodiment of the present invention, a pair of large annular steps are symmetrically arranged at both ends of the outer wall of the valve core housing 11, and six annular grooves are opened in the middle of the two large steps. The specific sizes of the large annular steps and the annular grooves are not restricted and are subject to actual needs.

[0036] In one embodiment of the present invention, the cross-sectional area of ​​the valve core cavity 13 in the coverage area of ​​the protrusion 14 corresponding to the valve core cavity 13 is consistent or changes regularly in the axial extension direction; the arrangement density of the protrusion 14 along the axial direction of the valve core cavity 13 is consistent or changes regularly.

[0037] It should be noted that the cross-sectional area of ​​the valve core cavity 13 is consistent or changes regularly, and the arrangement density of the protrusions 14 is consistent or changes regularly in order to make the molding process more convenient when molding the valve core cavity 13 and the protrusions 14, thereby ensuring that the protrusions 14 have a guaranteed degree of fixation on the deflection rod 12, improving the process production efficiency while ensuring sufficient anti-fatigue performance; Specifically, in the valve core cavity 13 where the protrusion 14 is provided, the extension direction of the valve core cavity 13 is not restricted, and it can be bent or folded as long as the cross-sectional area is consistent or changes regularly based on needs; the setting density of the dot matrix of the protrusion 14 on the inner wall of the valve core housing 11 varies with the simulated force changes, and the density is set regularly based on the simulated force change results.

[0038] However, within the range not covered by the protrusion 14 in the valve core cavity 13, there is no restriction on the gap distance between the valve core housing 11 and the deflection rod 12, that is, the valve core cavity 13 here. Therefore, the inner wall of the open end of the valve core housing 11 can be an inclined surface, or a toothed surface or a curved surface, etc., which is not restricted here.

[0039] In one embodiment of the present invention, a gas flow channel 131 is formed at the closed end 111 of the valve core cavity 13 , and the inner wall of the gas flow channel 131 is a topological curved surface structure.

[0040] It should be noted that the inner wall, ie the inner surface, of the gas flow channel 131 is a topological curved surface structure for guiding the gas in the valve core cavity 13 and for buffering, and therefore no protrusion 14 is provided in the gas flow channel 131 .

[0041] Therefore, the setting position of the protrusion 14 is the remaining part of the valve core cavity 13 except the gas flow channel 131, and can also extend to the port of the open end 112 of the valve core housing 11. The larger the setting area of ​​the protrusion 14, the stronger the fixation of the fatigue-resistant valve core 100, and the better the effect of resisting fatigue failure.

[0042] Specifically, in one embodiment of the present invention, the number of the gas flow channels 131 is two, which are respectively disposed on opposite sides of the bending rod 12 at the closed end 111 , and are both disposed at an angle to the bending rod 12 .

[0043] It can be understood that by continuing to topologically optimize the inner wall of the gas flow channel 131, the best curved surface design structure is found to guide and buffer the gas in the valve core cavity 13 to reduce the flow blockage of the gas in the valve core cavity 13 during operation, thereby affecting the accuracy of the servo valve 200.

[0044] The technical solution of the present invention adds a dot-matrix-arranged protrusion 14 in the valve core cavity 13 and adds a topological structure design at the end of the valve core cavity 13, so that the valve core is less affected by disturbances or even no longer disturbed, while improving the accuracy of the servo valve 200.

[0045] Please combine Figure 3-Figure 5 The present invention further proposes a servo valve 200, which includes a valve body 21, the valve body 21 includes a valve body shell 211, an anti-fatigue valve core 100 and a servo motor 22 arranged in the valve body shell 211, at least a part of the servo motor 22 is arranged in the valve body 21, the anti-fatigue valve core 100 includes a valve core housing 11, a deflection rod 12 arranged inside the valve core housing 11, the valve core housing 11 is hollow to form a valve core cavity 13, the deflection rod 12 is arranged in the valve core cavity 13, one end of the deflection rod 12 is connected to the valve core housing 11, and the other end extends out of the valve core cavity 13 for use with the servo motor 22; the inner wall of the valve core housing 11 is provided with a dot-matrix-arranged protrusion 14, the protrusion 14 is accommodated in the valve core cavity 13 and abuts the deflection rod 12, when the deflection rod 12 moves with the servo motor 22, the protrusion 14 abuts the deflection rod 12 to prevent the deflection rod 12 from radially displacing in the valve core cavity 13.

[0046] The specific structure of the anti-fatigue valve core 100 refers to the above embodiments. Since the servo valve 200 adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0047] The servo motor 22 includes a mover 221 , which is disposed inside the valve body 21 and is fixedly connected to or integrally formed with the deflection rod 12 of the valve core.

[0048] It should be noted that the conventional servo motor 22 usually adopts a rotary motor, which is generally composed of a motor rotor with an integrated crankshaft connected to the circular ring at the end of the valve core deflection rod 12. The eccentric crankshaft drives the circular ring to move during the rotation. The circular ring movement at this time has both the axial component of the valve core sliding and the component of the vertical sliding axis. The component of the vertical sliding axis will cause the valve core deflection rod 12 to bend in the valve core cavity 13; and because the lengthening of the deflection rod 12 can reduce the bending angle of the bottom of the deflection rod 12, the valve core design of most such direct-drive servo valves 200 is generally longer.

[0049] In the present application, the servo motor 22 adopts a linear motor, and one end of the flexure rod 12 is directly fixed to the mover 221 of the motor through a permanent magnet. The flexure rod 12 and the mover 221 of the servo motor 22 form a new mover, so that the flexure rod 12 becomes a part of the new mover. The flexure rod 12 does not need to be bent during the transmission process. The closed end 111 of the valve core cavity 13 opens a gas flow channel 131 with a topological structure, and the valve core cavity 13 is provided with a lattice structure. The end of the flexure rod 12 close to the servo motor 22 does not need to be designed with a circular hole that cooperates with the rotor crankshaft of the servo motor 22.

[0050] Optionally, one end of the deflection rod 12 may be integrally formed with an end of the mover 221 of the servo motor 22 .

[0051] It can be understood that these designs effectively avoid the disturbance of the anti-fatigue valve core 100, and even make the anti-fatigue valve core 100 no longer disturbed. At the same time, the fixed connection or integration of the servo motor 22 and the valve core deflection rod 12 simplifies the transmission structure of the servo motor 22 and the valve core, and also simplifies the processing technology of the connection end of the deflection rod 12 and the servo motor 22, thereby avoiding direct contact and friction failure between the rotor of the servo motor 22 and the end face of the deflection rod 12, thereby improving production efficiency and increasing the overall service life of the valve core.

[0052] Specifically, the fatigue life of the deflection rod 12 in the anti-fatigue valve core 100 increases by 1%-33%.

[0053] In addition, the installation space required for the linear motor is smaller, which further reduces the volume of the direct-drive servo valve 200. The opening method of the valve core cavity 13 in the anti-fatigue valve core 100 also reduces the weight of the valve core to a certain extent. According to the opening size of the valve core cavity 13, the overall weight reduction ratio of the anti-fatigue valve core 100 can be 1%-95%.

[0054] See also Figure 6 The present invention also proposes a valve core production process, comprising the following steps: S1: obtaining a three-dimensional model of the anti-fatigue valve core, and obtaining corresponding data information based on the three-dimensional model; S2: Provide raw materials based on the data information of the anti-fatigue valve core, stack them layer by layer from bottom to top, and solidify and connect the inside of the cross-sectional profiles of adjacent layers to obtain the initial product; S3: Perform preset post-processing on the initial product to obtain the required product.

[0055] It should be noted that the valve core production process is an additive manufacturing integrated molding process, wherein the molding process includes but is not limited to laser powder bed melting, electron beam powder bed melting, photocuring ceramic additive molding and binder injection molding; the corresponding data information obtained based on the three-dimensional model includes the height information of the anti-fatigue valve core, the corresponding height cross-sectional profile information, the energy beam scanning path information inside the profile, the slice data of the binder nozzle feeding path information inside the profile, and the structure and position of the dot array protrusions in the valve core; The raw materials may be one or more of steel, ceramics, and ceramic reinforced composite materials. The processing of raw materials varies with the type of raw materials and the process. Some processes do not require hot melting into liquid state for stacking molding. Therefore, the processing method of raw materials is not limited, and is subject to the raw material requirements of the corresponding molding process.

[0056] Specifically, the curing connection methods for the inner walls of the cross-sectional profiles of adjacent layers include sintering, bonding and curing, the purpose of which is to firmly connect the structures of the two adjacent layers to prevent deformation that affects the accuracy of use. The curing connection method is not limited and is subject to actual production needs.

[0057] It can be understood that this production process is an additive manufacturing process that obtains a valve core that meets the requirements through melting and spraying, sintering and solidification, and post-processing of pre-selected raw materials. It is simple to process and convenient to produce. The anti-fatigue valve core produced specifically adopts all the technical solutions of the anti-fatigue valve core of the above-mentioned embodiment, and therefore has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiment, which will not be repeated here one by one.

[0058] For further information, see Figure 7 , the preset post-processing includes the following steps: S31: performing heat treatment on the entire initial product for a preset period of time; S32: Perform post-processing based on the initial product after heat treatment to obtain the required product.

[0059] It should be noted that the molding of the gas flow channel with a topological surface structure in the valve core cavity is also included in the one-piece molding process. The structure of the gas flow channel is preferentially calculated through structural optimization algorithm and simulation algorithm, so that the gas flow channel with a topological surface structure can be obtained in the one-piece molding process.

[0060] In addition, due to the large differences in the materials used in the additive manufacturing one-piece molding process, processing defects such as low product surface accuracy, high surface roughness, residual stress and microcracks may seriously affect the performance and life of the product. For example, the inherent rapid heating and cooling properties will lead to uneven microstructure and accumulation of internal stress. Therefore, some auxiliary processes are usually required, such as post-processing heat treatment to change the microstructure and / or reduce residual stress to achieve performance comparable to or better than traditional manufacturing counterparts, as well as powder cleaning of the finished surface.

[0061] Specifically, there is no restriction on the time period for heat treatment. Different materials require different time periods for heat treatment, which shall be subject to actual production needs.

[0062] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An anti-fatigue valve core, Features: The anti-fatigue valve core comprises a valve core housing, a deflection rod arranged inside the valve core housing, one end of the valve core housing is closed to form a closed end, and the other end away from the closed end is an open end, and the closed end and the inner wall of the valve core housing define a valve core cavity; The deflection rod is arranged in the valve core cavity and fixedly connected to the closed end of the valve core housing. The inner wall of the valve core housing is provided with projections arranged in a dot matrix. The projections are accommodated in the valve core cavity and abut the deflection rod.

2. The anti-fatigue valve core according to claim 1, Features: The protrusions are arranged in an axially surrounding array on the inner wall of the valve core housing from the closed end to the open end, and the covering length is greater than or equal to three quarters of the length of the valve core housing.

3. The anti-fatigue valve core according to claim 2, Features: The cross-sectional area of ​​the valve core cavity in the axial extension direction corresponding to the coverage range of the protrusion is consistent or changes regularly; the arrangement density of the protrusions along the axial direction of the valve core cavity is consistent or changes regularly.

4. The anti-fatigue valve core according to claim 1, Features: The lattice arrangement of the protrusions includes at least one or more combinations of three-periodic minimal surface lattices.

5. The anti-fatigue valve core according to claim 4, Features: The protrusion is a divergent cellular structure with the lattice point on the valve core housing as the starting point, and each point of the cellular structure is connected by a truss rod or a three-period minimal surface, wherein the truss rod diameter of the protrusion or the width of the three-period minimal surface is 0.1 mm-10 mm, and the unit cell side length of the lattice is 0.2 mm-100 mm.

6. The anti-fatigue valve core according to claim 1, Features: A gas flow channel is provided at one end of the valve core cavity close to the connection between the deflection rod and the valve core housing, and the inner wall of the gas flow channel is a topological curved surface structure.

7. A servo valve, Features: The servo valve comprises a valve body, the valve body comprises a valve body shell, an anti-fatigue valve core and a servo motor arranged in the valve body shell, at least a part of the servo motor is arranged in the valve body, the anti-fatigue valve core comprises a valve core housing, a deflection rod arranged inside the valve core housing, the valve core housing is hollow to form a valve core cavity, the deflection rod is arranged in the valve core cavity, one end of the deflection rod is connected to the valve core housing, and the other end extends out of the valve core cavity to cooperate with the servo motor; The inner wall of the valve core housing is provided with projections arranged in a dot matrix, the projections are accommodated in the valve core cavity and abut the deflection rod, and when the deflection rod moves with the servo motor, the projections abut the deflection rod to prevent the deflection rod from radially displacing in the valve core cavity.

8. The servo valve according to claim 7, Features: The servo motor comprises a mover, which is arranged inside the valve body and is fixedly connected to or integrally formed with the deflection rod of the valve core.

9. A valve core production process for producing an anti-fatigue valve core as claimed in any one of claims 1 to 6, It is characterized in that The steps include: Acquire a three-dimensional model of the anti-fatigue valve core, and acquire corresponding data information based on the three-dimensional model; Provide raw materials based on the data information of the anti-fatigue valve core, stack them layer by layer from bottom to top, and solidify and connect the inside of the cross-sectional profiles of adjacent layers to obtain the initial product; The initial product is pre-processed to obtain the required product.

10. The valve core production process according to claim 9, It is characterized in that The preset post-processing comprises the following steps: Heat treatment of the initial product as a whole for a preset period of time; The initial product after heat treatment is post-processed to obtain the required product.

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