2D electro-hydraulic proportional reversing valve based on spiral proportional torque motor

Abstract

The 2D electro-hydraulic proportional reversing valve based on the spiral proportional torque motor comprises the spiral proportional torque motor, a 2D straight groove type valve body and an end cover, the end cover is fixedly connected with the spiral proportional torque motor and the 2D straight groove type valve body, the 2D straight groove type valve body comprises a valve sleeve and a valve element, one end of the valve sleeve is fixedly connected with the end cover, and the other end of the valve sleeve is fixedly connected with the end cover. The other end of the valve sleeve is sealed, an inner hole of the valve sleeve is sequentially provided with a port A, a port P, a port B and a port T, the port P is an oil inlet, the pressure of the port P is system pressure, the port T is an oil return port, and the pressure of the port T is zero; the valve element is movably connected into an inner hole formed in the valve sleeve in a sleeved mode, the valve element can rotate and axially move relative to the inner hole, a high-pressure hole d and two first circular beads adjacent to the high-pressure hole d are arranged in the middle of the valve element, and the middles of the two first circular beads are matched with a port A and a port B respectively. The 2D straight groove type valve body is further provided with a hydraulic resistance bridge used for controlling movement of the valve element.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of hydraulic transmission, and particularly relates to a 2D electro-hydraulic proportional reversing valve based on a screw type proportional torque motor. BACKGROUND

[0002] Since the appearance of electro-hydraulic servo control technology in the 1940s, it has occupied a high-end position in the mechatronic transmission and control technology with its high power-to-weight ratio, large output force (torque) and excellent static and dynamic characteristics, and is mainly applied to aerospace, military weapons, ships, large power stations, steel and other strategic industrial occasions, thus achieving great success. However, the electro-hydraulic servo valve is extremely sensitive to oil pollution, and is harsh in application and maintenance conditions. In addition, the pursuit of zero characteristics to meet the requirements of closed-loop control requires very strict machining and assembly precision of key components, which is difficult to be accepted by the industry. People generally hope to have a control technology with reliable performance, low price, control accuracy and response characteristics that can meet the actual needs of industrial control systems. Under this background, electro-hydraulic proportional control technology emerged as the times required. In 1967, the Swiss Beringer company first used a proportional electro-mechanical transducer (proportional electromagnet) in an industrial hydraulic valve, and the KL type proportional reversing valve produced was considered to be the world's first proportional valve. In the 1970s and 1980s, due to the application of various feedbacks such as pressure, flow, displacement and dynamic pressure and electrical correction means, the static and dynamic characteristics of the proportional valve were greatly improved, and the electro-hydraulic proportional control technology entered a golden age with the deep integration of the latest cartridge technology. Today, almost all traditional flow, pressure and reversing valves can find corresponding electro-hydraulic proportional valve products, which have been widely used in industrial production.

[0003] The proportional directional valve requires continuous proportional positioning control of the displacement (position) of the spool. The simplest way is to linearly convert the thrust output of the proportional electromagnet into the displacement of the spool by a spring, which is also the basic working principle of single-stage or direct-acting proportional directional valves or flow valves. However, due to the Bernoulli effect, the oil flowing through the valve port will exert a hydraulic force (also known as Bernoulli force) on the spool, and the size of the force is proportional to the product of the opening area of the valve port and the pressure drop. Therefore, as the pressure difference of the valve port increases, the proportional characteristics of the direct-acting proportional valve will deteriorate significantly, and even the abnormal phenomenon that the flow through the proportional valve decreases with the increase of the pressure difference of the valve port occurs. Therefore, the principle of balancing the position of the spool by the thrust of the electromagnet and the force of the spring only applies to proportional valves with small flow, and the maximum working flow in practical application is generally below 15 L / min (maximum working pressure is 21 MPa). In addition, in order to achieve the balance of the axial static pressure, the direct-acting proportional directional valve or flow valve adopts the spool structure, which is easy to be affected by friction and oil pollution and appear "stuck" phenomenon. If the direct-acting proportional directional valve or flow valve wants to obtain good proportional characteristics, the matching between the spool and the spool hole must reach high precision, especially the cylindricity which is sensitive to friction. For example, the cylindricity of the φ6 proportional valve spool of a foreign company is within 1 micron, which is as high as the precision requirement of the servo valve spool. Domestic ordinary hydraulic component manufacturers are difficult to achieve this, which is one of the main reasons for the poor performance of domestic direct-acting proportional directional valves. The use of linear displacement sensor (LVDT) to measure and close-loop control the position of the spool forms an electric feedback type direct-acting proportional directional valve, which can greatly improve the positioning stiffness and control accuracy of the spool, and ultimately make the electric feedback direct-acting proportional valve can be applied to the closed-loop control of the hydraulic system like the servo valve (such valve is called proportional servo valve). However, due to the limitation of magnetic saturation, the output force of the proportional electromagnet is limited, and it is impossible to fundamentally solve the problem of the influence of hydraulic force under high pressure and large flow. In the working state of high pressure (large pressure difference) and large flow, the flow saturation phenomenon still occurs.

[0004] The most fundamental way to eliminate the influence of hydraulic force and improve the flow capacity of hydraulic valve is to use pilot control (pilot control) technology. As early as 1936, American engineer Harry Vickers invented the pilot-controlled overflow valve to solve the problem that the direct-acting overflow valve cannot realize pressure control in high-pressure and large-flow systems due to the influence of hydraulic force. The basic idea is to use a smaller pilot valve to control the static pressure and drive the main spool to move. Because the hydraulic thrust is much larger than the hydraulic force generated when the oil flows through the valve port, it is enough to eliminate the adverse effects on the movement and control of the main spool. The idea of pilot control has been widely used in the design of other hydraulic valves, making high-pressure and large-flow control of hydraulic systems a reality. Later, various electro-hydraulic servo control elements also followed the design idea of pilot control, including electro-hydraulic proportional valves.

[0005] Among the numerous innovations of pilot stage structure, the flow amplification mechanism based on the spool two dimensional (2D) design integrates the originally separate pilot stage and power stage into a single spool, which is not only simple in structure and fast in dynamic response, but more importantly, the anti-pollution ability of the valve is greatly improved. A kind of direct-acting-pilot integrated 2D electro-hydraulic proportional directional valve is proposed by Quan Jian et al., which combines 2D valve with proportional electromagnet through pressure-torque amplification technology, so that it has the advantages of both direct-acting and pilot-controlled electro-hydraulic proportional directional valves. In addition, it has strong anti-pollution ability and no special high requirements for machining precision, so it has good prospects for large-scale production and application. The main problem of the valve is that the pressure-torque coupling joint, which plays a role in pressure-torque amplification, is a roller inclined plane mechanical mechanism. The non-linear elements such as friction and assembly gap will have a great impact on the linearity, repeatability and hysteresis of the electro-hydraulic proportional valve.

[0006] In order to solve the impact of the mechanical pressure-torque coupling of the traditional 2D electro-hydraulic proportional directional valve on the linearity, repeatability and hysteresis of the valve, a kind of magnetic suspension coupling joint type electro-hydraulic servo proportional valve is proposed by Meng Bin et al., which combines magnetic suspension coupling joint with proportional electromagnet to achieve pressure-torque amplification. The input end and the output end of the magnetic suspension coupling joint are not in contact, and the transmission torque is achieved through magnetic repulsion. In this way, the impact of inherent gap and friction on the linearity, repeatability and hysteresis of the valve is avoided. Since the spool stroke of the magnetic suspension coupling joint type two-dimensional servo proportional valve is ±2mm, the magnetic repulsion working air gap of the magnetic suspension coupling joint cannot be reduced to a very small size (objective physical phenomenon: the magnetic force increases exponentially with the decrease of the working air gap). A large torque is required to drive the spool rotation, so a large size permanent magnet must be designed for torque transmission, which limits the further improvement of the power to weight ratio. In addition, the large magnetic repulsion force makes the assembly process of the entire magnetic suspension coupling joint very difficult. SUMMARY

[0007] In order to solve the above problems, the present application provides a kind of 2D electro-hydraulic proportional directional valve based on screw type proportional torque motor:

[0008] A kind of 2D electro-hydraulic proportional directional valve based on screw type proportional torque motor includes screw type proportional torque motor, 2D straight slot type valve body and end cover, the end cover is fixedly connected with screw type proportional torque motor and 2D straight slot type valve body respectively,

[0009] The 2D straight slot type valve body includes valve sleeve and spool, one end of the valve sleeve is fixedly connected with the end cover, the other end of the valve sleeve is sealed, and A port, P port, B port and T port are sequentially opened on the inner hole of the valve sleeve, wherein the P port is an oil inlet port, the P port pressure is the system pressure, and the T port is an oil return port, the T port pressure is zero;

[0010] The valve core is movably sleeved in the inner hole of the valve sleeve, the valve core can rotate and axially move relative to the inner hole, a high-pressure hole d and two first shoulders of adjacent high-pressure holes d are arranged on the middle part of the valve core, the two first shoulders are respectively matched with the A port and the B port, and the 2D straight groove type valve body is further provided with a hydraulic resistance bridge for controlling the movement of the valve core;

[0011] The spiral proportional torque motor is connected with the valve core, the connection spiral proportional torque motor is used for outputting steering and axial force to the valve core; in a normal state, the two first shoulders are respectively sealed and blocked with the A port and the B port, when the valve core axially moves, the two first shoulders are dislocated relative to the A port and the B port, the A port and the P port are communicated with each other, and the B port and the T port are communicated with each other.

[0012] Preferably, a second concentric ring is sleeved on the right end of the valve core, the right end of the valve core is close to the spiral proportional torque motor, a plug is sleeved on the left end of the valve core, the plug is sleeved in the positioning pin, the left end of the valve core, the plug and the valve sleeve form a closed sensitive cavity A, the right end of the valve core, the second concentric ring and the second shoulder of the valve sleeve form a closed high-pressure cavity B, and the stress area of the high-pressure cavity B is 1 / 2 of the sensitive cavity A.

[0013] A high-pressure circular hole e and a high-pressure rectangular groove c which are communicated with the P port are arranged on the valve core, and a low-pressure rectangular groove b which is communicated with the T port is also arranged on the valve core, a sensing channel a which is communicated with the sensitive cavity A is arranged on the edge inner hole wall of the valve sleeve, the sensing channel a, the low-pressure rectangular groove b and the high-pressure rectangular groove c form a hydraulic resistance bridge, and the hydraulic resistance bridge controls the pressure of the sensitive cavity A.

[0014] Preferably, the spiral proportional torque motor comprises a shell unit, a torque motor unit and a middle shaft assembly, the middle shaft assembly is movably arranged in a cylindrical built-in cavity arranged in the shell unit, the middle shaft assembly comprises an armature, a spiral magnetic coupling and an elastic reset member, the armature is connected with the torque motor unit, the torque motor unit generates an X-axis moving force on the armature, and the elastic reset member is connected with the armature and is used for controlling the elastic reset of the armature.

[0015] Preferably, the helical magnetic coupling is sleeved with a linear bearing, the linear bearing is installed in a cylindrical built-in cavity, the helical magnetic coupling is composed of an input end and an output end that are screwed together, a working air gap is arranged between the input end and the output end, the input end comprises an input mover that is in transmission connection with an armature and an input permanent magnet that is clamped and installed on the input mover, the output end comprises an output mover and an output permanent magnet that is clamped and installed on the output mover, the output mover and the input mover are screw structures that are screwed together and matched, the output mover and the input mover are the same in pitch, initial angle, helical direction and height, the output permanent magnet and the input permanent magnet are opposite in magnetization direction, the output permanent magnet and the input permanent magnet are both in the shape of a helix, the output permanent magnet and the input permanent magnet are the same in pitch, initial angle and helical direction as the output mover, and the output mover can rotate and translate along the X axis, and has two degrees of freedom. The 2D electro-hydraulic proportional switching valve based on the helical proportional torque motor is designed, and a helical proportional torque motor based on a mixed differential magnetic circuit structure is used. The torque motor realizes force compensation through a bypass air gap, can make the magnetic circuit shunt generated by coil excitation be two paths in the axial and radial directions, and finally combine the output force that meets the horizontal force-displacement characteristics on the armature, so that the linear range is large.

[0016] Preferably, the torque motor unit comprises a left yoke, a coil, a framework, a left permanent magnet, a left retainer, a first concentric ring, a right retainer, a right permanent magnet, a right yoke, an elastic reset member, a middle yoke and a linear bearing, and the left yoke, the framework, the left permanent magnet, the left retainer, the first concentric ring, the right retainer, the right permanent magnet, the right yoke, the elastic reset member, the middle yoke and the linear bearing are arranged concentrically.

[0017] The middle yoke is fixedly connected with the armature, the left permanent magnet generates polarized magnetic flux between the left yoke, the left retainer and the middle yoke, the left permanent magnet is provided with a left compensation air gap magnetic flux between the left retainer and the middle yoke, and a left working air gap magnetic flux between the left yoke and the middle yoke.

[0018] The right permanent magnet generates polarized magnetic flux between the right yoke, the right retainer and the middle yoke, the right permanent magnet is provided with a right compensation air gap magnetic flux between the right retainer and the middle yoke, and a right working air gap magnetic flux between the right yoke and the middle yoke.

[0019] The coil is wound on the framework and is used for generating excitation magnetic flux; the excitation magnetic flux and the polarized magnetic flux are differentially superimposed and are used for generating output force on the armature; the compensation magnetic force generated by the left compensation air gap magnetic flux and the right compensation air gap magnetic flux interacts with the main magnetic force generated by the working air gap magnetic flux, so that the output force and the current are in proportional relationship.

[0020] Preferably, the materials of the left yoke, the left retainer, the right retainer, the right yoke, the middle yoke, the output mover and the input mover are DT4C.

[0021] Preferably, the material of the left permanent magnet, the right permanent magnet, the output permanent magnet and the input permanent magnet is neodymium iron boron.

[0022] Preferably, the material of the skeleton and the first concentric ring is copper.

[0023] Preferably, the elastic reset member comprises a spring set, a spring seat and a zero adjustment nut, the spring seat is sleeved to the armature away from one end of the spiral magnetic coupling, the spring set is sleeved to the armature and forms elastic adaptation with the spring seat, one end of the spring set forms abutting cooperation with the inner top wall of the cylindrical built-in cavity, the other end of the spring set forms abutting cooperation with the zero adjustment nut, and the zero adjustment nut is threadedly matched with the cavity opening of the cylindrical built-in cavity.

[0024] Preferably, the shell unit comprises a front cover and a shell fixedly connected with each other, the front cover is fixedly connected with the end cover, and the shell is threadedly connected with the zero adjustment nut.

[0025] Preferably, the materials of the front cover, the zero adjustment nut and the spring seat are aluminum, and the material of the shell is DT4C.

[0026] The beneficial effects of the present application mainly include:

[0027] 1. The 2D electro-hydraulic proportional reversing valve based on the spiral proportional torque motor designed in the present application uses a spiral magnetic coupling to realize the function of converting straight motion into rotary motion, and the whole force transmission process is completed through magnetic repulsion, so that the whole motion process is free of friction and wear, and the negative influence of factors such as linearity, repeatability and hysteresis on static / dynamic characteristics is fundamentally avoided.

[0028] 2. The 2D electro-hydraulic proportional reversing valve based on the spiral proportional torque motor designed in the present application adopts a two-dimensional flow amplification mechanism with two degrees of freedom of the valve core, integrates the pilot stage and the power stage on a single valve core, greatly improves the power-to-weight ratio while simplifying the structure and reducing the processing cost. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is an assembly schematic view of the embodiment;

[0030] Figure 2 It is a structural schematic view of the embodiment;

[0031] Figure 3 a~ Figure 3 c is an exploded view of the spiral magnetic coupling, wherein, Figure 3 a is a whole view, Figure 3 b is an exploded view of the output rotor and the input rotor, Figure 3 c is a complete exploded view;

[0032] Figure 4A schematic diagram showing the magnetization direction of a spiral magnetic coupling;

[0033] Figure 5 This is a schematic diagram of the embodiment in a balanced state;

[0034] Figure 6 This is a schematic diagram of the embodiment in the powered-on state;

[0035] Figure 7 This is a schematic diagram of the valve core rotating in an embodiment.

[0036] Figure 8 This is a schematic diagram of the valve core in a translational state, as shown in the embodiment.

[0037] Figure 9 This is a schematic diagram of the state of returning to zero in the example.

[0038] Figure 10 This is a structural diagram of the valve core for an embodiment.

[0039] Figure 11 The structure of the outer shell in Example 2 Figure 1 .

[0040] Figure 12 The structure of the outer shell in Example 2 Figure 2 .

[0041] Reference numerals: 1. Valve sleeve; 2. Valve core; 021. First shoulder; 022. Second shoulder; 3. Front cover; 4. Housing; 5a. Left yoke; 5b. Right yoke; 6. Coil; 7. Frame; 8a. Left permanent magnet; 8b. Right permanent magnet; 9a. Left cage; 9b. Right cage; 10. First concentric ring; 11. Zeroing nut; 12. Spring assembly; 13. Spring seat; 14. Armature; 15. Middle yoke; 16. Linear bearing; 17. Helical magnetic coupling; 18. End cover; 19. Second concentric ring; 20. Plug; 21. Locating pin; 22a. Output mover; 22b. Input mover; 23a. Output permanent magnet; 23b. Input permanent magnet. Detailed Implementation

[0042] The following is in conjunction with the appendix Figures 1-12 The present invention will be further described with reference to Examples 1-2.

[0043] Define the three-dimensional coordinate axes: the forward / backward direction is the Y-axis, with the forward direction as the positive Y-axis; the left / right direction is the X-axis, with the right direction as the positive X-axis; and the up / down direction is the Z-axis, with the up direction as the positive Z-axis. In the attached diagram of the manual, A, P, B, and T represent ports A, P, B, and T, respectively.

[0044] Example: Figures 1-2As shown, a 2D electro-hydraulic proportional directional valve based on a helical proportional torque motor includes a helical proportional torque motor, a 2D straight groove valve body, and an end cap 18, wherein the end cap 18 is fixedly connected to the helical proportional torque motor and the 2D straight groove valve body respectively.

[0045] The 2D straight groove valve body includes a valve sleeve 1, a valve core 2, a plug 20, and a positioning pin 21. One end of the valve sleeve 1 is fixedly connected to an end cap 18, and the other end of the valve sleeve 1 is sealed by the plug 20. The inner hole of the valve sleeve 1 has ports A, P, B, and T in sequence, where port P is the oil inlet and the pressure at port P is the system pressure, port T is the oil return port, and the pressure at port T is zero.

[0046] like Figure 1 As shown, the valve core 2 is movably sleeved in the inner hole of the valve sleeve 1. The valve core 2 can rotate and move axially relative to the inner hole. The valve core 2 is provided with a high pressure hole d and two adjacent high pressure holes d first shoulders 021. The two first shoulders 021 are respectively adapted to port A and port B. The 2D straight groove valve body is also provided with a hydraulic resistance bridge for controlling the movement of the valve core 2.

[0047] The spiral proportional torque motor drives the valve core 2. The spiral proportional torque motor is used to output steering and axial force to the valve core 2. Under normal conditions, the two first shoulders 021 form a sealing block with port A and port B respectively. When the valve core 2 is axially displaced, the two first shoulders 021 are misaligned relative to port A and port B. Port A and port P are connected to each other, and port B and port T are connected to each other.

[0048] The right end of the valve core 2 is sealed with a second concentric ring 19. The right end of the valve core 2 is the end closest to the helical proportional torque motor. The left end of the valve core 2 is sealed with a plug 20. The plug 20 is fitted into the positioning pin 21. The left end of the valve core 2, the plug 20 and the valve sleeve 1 form a sealed sensitive cavity A. The right end of the valve core 2, the second concentric ring 19 and the second shoulder 022 of the valve sleeve 1 form a sealed high-pressure cavity B. The force-bearing area of ​​the high-pressure cavity B is 1 / 2 of that of the sensitive cavity A.

[0049] A high-pressure circular hole e and a high-pressure rectangular groove c, both communicating with port P, are provided on the valve core 2. A low-pressure rectangular groove b, communicating with port T, is also provided. A sensing channel a, communicating with the sensitive cavity A, is provided on the inner wall of the valve sleeve 1. The sensing channel a, the low-pressure rectangular groove b, and the high-pressure rectangular groove c constitute a hydraulic resistance bridge, which controls the pressure of the sensitive cavity A.

[0050] The screw type proportional torque motor comprises a housing unit, a torque motor unit and a middle shaft assembly, the middle shaft assembly is movably installed in a cylindrical built-in cavity provided in the housing unit, the middle shaft assembly comprises an armature 14, a screw type magnetic coupling 17 and an elastic reset member, the armature 14 is drivingly connected to the torque motor unit, the torque motor unit generates an X-axis moving force on the armature 14, and the elastic reset member is connected to the armature 14 and used for controlling elastic reset of the armature 14. The elastic reset member comprises a spring set 12, a spring seat 13 and a zero setting nut 11, the spring seat 13 is fixedly sleeved to an end of the armature 14 away from the screw type magnetic coupling 17, the spring set 12 is sleeved to the armature 14 and elastically matched with the spring seat 13, one end of the spring set 12 is top abutting matched with an inner top wall of the cylindrical built-in cavity, the other end of the spring set 12 is top abutting matched with the zero setting nut 11, and the zero setting nut 11 is threadingly matched with a cavity opening of the cylindrical built-in cavity.

[0051] The screw type magnetic coupling 17 is externally sleeved with a linear bearing 16, and the linear bearing 16 is installed in the cylindrical built-in cavity. Figures 3-5 As shown in the figure, the screw type magnetic coupling 17 is composed of an input end and an output end which are mutually screwed, a working air gap is provided between the input end and the output end, the input end comprises an input mover 22b drivingly connected to the armature 14 and an input permanent magnet 23b clamped and installed on the input mover 22b, the output end comprises an output mover 22a and an output permanent magnet 23a clamped and installed on the output mover 22a, the output mover 22a and the input mover 22b are mutually screwed and matched in a spiral structure, the pitch, the initial angle, the spiral direction and the height of the output mover 22a and the input mover 22b are all the same, the magnetization directions of the output permanent magnet 23a and the input permanent magnet 23b are opposite, the output permanent magnet 23a and the input permanent magnet 23b are both in a spiral shape, and the pitch, the initial angle and the spiral direction of the output permanent magnet 23a and the input permanent magnet 23b are all the same as those of the output mover 22a. The input mover 22b is threadedly connected to the armature 14, and the output mover 22a is threadedly connected to the valve core 2. Since the output mover 22a is connected to the valve core 2, the output mover 22a can rotate and translate along the X-axis and has two degrees of freedom.

[0052] The 2D electro-hydraulic proportional switching valve based on the screw type proportional torque motor designed in the application uses the screw type proportional torque motor based on a mixed differential magnetic circuit structure. The torque motor uses a bypass air gap to realize force compensation, can make the magnetic circuit shunt generated by the coil 6 excitation be two paths of axial and radial, finally be combined into an output force meeting the horizontal force-displacement characteristic on the armature 14, and has a large linear range.

[0053] The torque motor unit comprises a left yoke 5a, a coil 6, a skeleton 7, a left permanent magnet 8a, a left retainer 9a, a first concentric ring 10, a right retainer 9b, a right permanent magnet 8b, a right yoke 5b, an elastic reset member, a middle yoke 15 and a linear bearing 16, which are concentrically arranged. The armature 14 is in interference fit with the middle yoke 15; the armature 14 is in threaded connection with the spring seat 13; the zero adjustment nut 11 is in threaded connection with the shell 4; the front cover 3 is fixed with the shell 4 through screws; the front cover 3 is in interference fit; and the linear bearing 16 is in interference fit with the right yoke 5b. The left permanent magnet 8a generates polarized magnetic flux between the left yoke 5a, the left retainer 9a and the middle yoke 15, and is provided with a left compensation air gap magnetic flux between the left retainer 9a and the middle yoke 15 and a left working air gap magnetic flux between the left yoke 5a and the middle yoke 15. The right permanent magnet 8b generates polarized magnetic flux between the right yoke 5b, the right retainer 9b and the middle yoke 15, and is provided with a right compensation air gap magnetic flux between the right retainer 9b and the middle yoke 15 and a right working air gap magnetic flux between the right yoke 5b and the middle yoke 15.

[0054] The coil 6 is wound on the skeleton 7 and used for generating excitation magnetic flux; the excitation magnetic flux and the polarized magnetic flux are differentially superimposed and used for generating output force on the armature 14; and the compensation magnetic force generated by the left compensation air gap magnetic flux and the right compensation air gap magnetic flux interacts with the main magnetic force generated by the working air gap magnetic flux, so that the output force is in proportional relationship with the current.

[0055] The materials of the left yoke 5a, the left retainer 9a, the right retainer 9b, the right yoke 5b, the middle yoke 15, the output mover 22a and the input mover 22b are DT4C. The materials of the left permanent magnet 8a, the right permanent magnet 8b, the output permanent magnet 23a and the input permanent magnet 23b are neodymium iron boron. The materials of the skeleton 7 and the first concentric ring 10 are copper. The shell unit comprises the front cover 3 and the shell 4 which are fixedly connected with each other, the front cover 3 is fixedly connected with the end cover 18, and the shell 4 is in threaded connection with the zero adjustment nut 11. The materials of the front cover 3, the zero adjustment nut 11 and the spring seat 13 are aluminum, and the material of the shell 4 is DT4C.

[0056] The working principle of the embodiment of the application is decomposed as shown in Figure 5 、 6 、7、8、9.

[0057] Figure 5The schematic diagram of 2D electro-hydraulic proportional directional valve based on helical proportional torque motor in equilibrium state. At the helical proportional torque motor, the left permanent magnet 8a generates polarized magnetic flux between the left yoke 5a, the left retainer 9a and the middle yoke 15; the right permanent magnet 8b generates polarized magnetic flux between the right yoke 5b, the right retainer 9b and the middle yoke 15; the helical magnetic coupling 17 is in the initial equilibrium position, the output rotor 22a and the input rotor 22b are in force balance, w0 = w0, F1 = F2. At the 2D straight slot valve body, the force area of the spool 2 at the end of the sensitive cavity A is twice that of the high pressure cavity B, the oil pressure of the sensitive cavity A is half of the high pressure cavity B, and the spool 22 is in force balance. The oil pressure of the sensitive cavity A is generated by adjusting the hydraulic resistance bridge composed of the sensing channel a, the low pressure rectangular groove b and the high pressure rectangular groove c. At this time, the A port, the B port, the P port and the T port are not communicated with each other.

[0058] Figure 6 The schematic diagram of 2D electro-hydraulic proportional directional valve based on helical proportional torque motor in energized state. When the coil 6 is energized, the excitation magnetic circuit generated by the coil 6 interacts with the polarized magnetic flux generated by the permanent magnet, resulting in the superposition of the magnetic flux of the left end working air gap of the armature 14 and the reduction of the magnetic flux of the right end working air gap of the armature 14. Therefore, the armature 14 is subjected to a thrust along the positive direction of the X axis. The thrust is constrained by the spring set 12, and finally pushes the armature 14 to displace xi. The armature 14 drives the input rotor 22b to move xi along the positive direction of the X axis, resulting in the change of the working air gap between the output rotor 22a and the input rotor 22b, w1 < w2, F3 > F4. Due to the influence of the hydraulic force, the thrust of the output rotor 22a cannot drive the spool 2 to move along the positive direction of the X axis. However, the thrust of the output rotor 22a generates a counterclockwise torque M1 along the positive direction of the X axis, which can drive the spool 2 to rotate.

[0059] Figure 7 The schematic diagram of 2D electro-hydraulic proportional directional valve based on helical proportional torque motor in the rotating state of the spool 2. The spool 2 is subjected to the torque M1 to rotate by an angle of θ. During the rotation, the working air gap between the output rotor 22a and the input rotor 22b changes, w1 gradually increases to w3, and w2 gradually decreases to w4. The rotation of the spool 2 causes the communication area between the sensing channel a and the low pressure rectangular groove b to increase, and the communication area between the sensing channel a and the high pressure rectangular groove c to decrease, finally causing the oil pressure of the sensitive cavity A to decrease. Therefore, the spool 2 breaks the force balance and is subjected to a huge thrust along the positive direction of the X axis generated by the hydraulic resistance bridge (much larger than the hydraulic force).

[0060] Figure 8The schematic diagram of 2D electro-hydraulic proportional directional valve based on helical proportional torque motor in the valve spool 2 translation state. The valve spool 2 is displaced by the huge thrust along the X positive direction generated by the hydraulic resistance bridge, resulting in the A port and the P port being communicated, and the B port and the T port being communicated. The valve spool 2 in the displacement process will cause the working air gap between the output mover 22a and the input mover 22b to change, w3 gradually becomes w5, w6 gradually becomes w7, and the output mover 22a is subjected to the action of F6 and F5. A clockwise torque M2 along the X axis positive direction is generated.

[0061] Figure 9 The schematic diagram of 2D electro-hydraulic proportional directional valve based on helical proportional torque motor in the return to zero position state. The valve spool 2 is rotated by an angle of a along the X axis positive direction clockwise by the torque M2, and is rotated until the working air gap between the output mover 22a and the input mover 22b is equal, w0=w0. The rotation of the valve spool 2 causes the communication area of the sensing channel a and the low-pressure rectangular groove b to decrease, and the communication area of the sensing channel a and the high-pressure rectangular groove c to increase, finally resulting in the oil pressure in the sensitive cavity A increasing to half of the oil pressure in the high-pressure cavity B. Therefore, the valve spool 2 restores the force balance and comes to a new equilibrium point. Finally, the displacement xo of the valve spool 2 is the same as the displacement xi of the armature 14.

[0062] In example 2, the surface of the shell is coated with high-temperature thermal insulation paint. The shell is manufactured by 3D metal printing technology, and the material is aluminum-silicon 12 iron. The surface of the shell is provided with two axially extending first and second heat dissipation flow channels, and the outer ends of the first and second heat dissipation flow channels are respectively provided with oil ports I1 and I2. The oil ports I1 and I2 input oil from the hydraulic system, and the oil flows back to the oil tank through the first and second heat dissipation flow channels from oil ports O1 and O2. In this process, the oil takes away the excess heat of the electromechanical transducer, ensuring the appropriate working temperature.

[0063] Obviously, the above embodiments of the present application are only examples for illustrating the present application, and are not intended to limit the embodiments of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. All embodiments do not need to be exhausted, and the obvious changes or variations derived from the essential spirit of the present application still belong to the protection scope of the present application.

Claims

1. A 2D electro-hydraulic proportional directional valve based on a helical proportional torque motor, characterized in that: It comprises a helical proportional torque motor, a 2D straight slot valve body and an end cover (18) fixedly connected with the helical proportional torque motor and the 2D straight slot valve body respectively, The 2D straight slot valve body comprises a valve sleeve (1) and a valve core (2), one end of the valve sleeve (1) is fixedly connected with the end cover (18), the other end of the valve sleeve (1) is sealed, and an A port, a P port, a B port and a T port are sequentially arranged on the inner hole of the valve sleeve (1), wherein the P port is an oil inlet port, the pressure of the P port is the system pressure, and the T port is an oil return port, and the pressure of the T port is zero. The valve core (2) is movably sleeved in the inner hole of the valve sleeve (1), the valve core (2) can rotate and axially move relative to the inner hole, a high-pressure hole d and a first shoulder (021) of two adjacent high-pressure holes d are arranged on the middle part of the valve core (2), the two first shoulders (021) are respectively matched with the A port and the B port, and the 2D straight slot valve body is further provided with a hydraulic resistance bridge for controlling the movement of the valve core (2). The helical proportional torque motor is drivingly connected with the valve core (2), and the helical proportional torque motor is used for outputting steering and axial acting force to the valve core (2). In a normal state, the two first shoulders (021) are respectively sealed and blocked with the A port and the B port, when the valve core (2) axially moves, the two first shoulders (021) are misaligned relative to the A port and the B port, the A port and the P port are communicated with each other, and the B port and the T port are communicated with each other.

2. A 2D electro-hydraulic proportional directional valve based on a helical proportional torque motor according to claim 1, characterized in that: A second concentric ring (19) is sealingly sleeved on the right end of the valve core (2), the right end of the valve core (2) is close to the helical proportional torque motor, a plug (20) is sealingly sleeved on the left end of the valve core (2), the plug (20) is sleeved in a positioning pin (21), and the left end of the valve core (2), the plug (20) and the valve sleeve (1) form a sealed sensitive cavity A, the right end of the valve core (2), the second concentric ring (19) and a second shoulder of the valve sleeve (1) form a sealed high-pressure cavity B, and the stress area of the high-pressure cavity B is 1 / 2 of that of the sensitive cavity A. A high-pressure circular hole e and a high-pressure rectangular groove c, which are communicated with the P port, are arranged on the valve core (2), and a low-pressure rectangular groove b, which is communicated with the T port, is also arranged on the valve core (2), a sensing channel a, which is communicated with the sensitive cavity A, is arranged on the side inner hole wall of the valve sleeve (1), the sensing channel a, the low-pressure rectangular groove b and the high-pressure rectangular groove c form a hydraulic resistance bridge, and the hydraulic resistance bridge controls the pressure of the sensitive cavity A.

3. The 2D electro-hydraulic proportional directional valve based on the helical proportional torque motor according to claim 1, characterized in that: The helical proportional torque motor comprises a shell unit, a torque motor unit and a middle shaft assembly, the middle shaft assembly is movably arranged in a cylindrical built-in cavity arranged in the shell unit, the middle shaft assembly comprises an armature (14), a helical magnetic coupling (17) and an elastic reset member, the armature (14) is drivingly connected with the torque motor unit, the torque motor unit generates an X axial moving force on the armature (14), and the elastic reset member is connected with the armature (14) and is used for controlling the elastic reset of the armature (14). The helical magnetic coupling (17) is sleeved with a linear bearing (16), the linear bearing (16) is installed in a cylindrical built-in cavity, the helical magnetic coupling (17) is composed of an input end and an output end which are screwed together, a working air gap is arranged between the input end and the output end, the input end comprises an input mover (22b) which is in driving connection with the armature (14) and an input permanent magnet (23b) which is clamped and installed on the input mover (22b), the output end comprises an output mover (22a) and an output permanent magnet (23a) which is clamped and installed on the output mover (22a), the output mover (22a) and the input mover (22b) are helical structures which are screwed together, the pitch, the initial angle, the helical direction and the height of the output mover (22a) and the input mover (22b) are the same, the magnetization directions of the output permanent magnet (23a) and the input permanent magnet (23b) are opposite, the structures of the output permanent magnet (23a) and the input permanent magnet (23b) are helical shapes, the pitch, the initial angle and the helical direction of the output permanent magnet (23a) and the input permanent magnet (23b) are the same as those of the output mover (22a), and the output mover (22a) can rotate and translate along the X axis and has two degrees of freedom.

4. The 2D electro-hydraulic proportional directional valve based on the helical proportional torque motor according to claim 1, characterized in that: The torque motor unit comprises a left yoke (5a), a coil (6), a skeleton (7), a left permanent magnet (8a), a left retainer (9a), a first concentric ring (10), a right retainer (9b), a right permanent magnet (8b), a right yoke (5b), and an elastic reset member, and the left yoke (5a), the skeleton (7), the left permanent magnet (8a), the left retainer (9a), the first concentric ring (10), the right retainer (9b), the right permanent magnet (8b), the right yoke (5b), the elastic reset member, a middle yoke (15) and a linear bearing (16) are concentrically arranged; The middle yoke (15) is fixedly connected with the armature (14), the left permanent magnet (8a) generates polarized magnetic flux between the left yoke (5a), the left retainer (9a) and the middle yoke (15), and the left permanent magnet (8a) is provided with a left compensation air gap magnetic flux between the left retainer (9a) and the middle yoke (15) and a left working air gap magnetic flux between the left yoke (5a) and the middle yoke (15); The right permanent magnet (8b) generates polarized magnetic flux between the right yoke (5b), the right retainer (9b) and the middle yoke (15), and the right permanent magnet (8b) is provided with a right compensation air gap magnetic flux between the right retainer (9b) and the middle yoke (15) and a right working air gap magnetic flux between the right yoke (5b) and the middle yoke (15); The coil (6) is wound on the skeleton (7) and is used for generating excitation magnetic flux; the excitation magnetic flux and the polarized magnetic flux are differentially superimposed and used for generating an output force on the armature (14); and the compensation magnetic force generated by the left compensation air gap magnetic flux and the right compensation air gap magnetic flux interacts with the main magnetic force generated by the working air gap magnetic flux, so that the output force is proportional to the current.

5. A 2D electro-hydraulic proportional directional valve based on a helical proportional torque motor according to claim 4, characterized in that: The materials of the left yoke iron (5a), the left retainer (9a), the right retainer (9b), the right yoke iron (5b), the middle yoke iron (15), the output mover (22a) and the input mover (22b) are DT4C.

6. A 2D electro-hydraulic proportional directional valve based on a helical proportional torque motor according to claim 4, characterized in that: The materials of the left permanent magnet (8a), the right permanent magnet (8b), the output permanent magnet (23a) and the input permanent magnet (23b) are neodymium iron boron.

7. A 2D electro-hydraulic proportional directional valve based on helical proportional torque motor according to claim 4, characterized in that: The materials of the skeleton (7) and the first concentric ring (10) are copper.

8. A 2D electro-hydraulic proportional directional valve based on a helical proportional torque motor according to claim 4, characterized in that: The elastic reset member comprises a spring set (12), a spring seat (13) and a zero adjustment nut (11), the spring seat (13) is fixedly sleeved with the armature (14) away from one end of the spiral magnetic coupling (17), the spring set (12) is sleeved with the armature (14) and forms an elastic fit with the spring seat (13), one end of the spring set (12) forms an abutting fit with the inner top wall of the cylindrical built-in cavity, the other end of the spring set (12) forms an abutting fit with the zero adjustment nut (11), and the zero adjustment nut (11) is threadedly fitted with the cavity opening of the cylindrical built-in cavity.

9. A 2D electro-hydraulic proportional directional valve based on helical proportional torque motor according to claim 3, characterized in that: The shell unit comprises a front cover (3) and a shell (4) fixedly connected with each other, the front cover (3) is fixedly connected with the end cover (18), and the shell (4) is threadedly connected with the zero adjustment nut (11).

10. A 2D electro-hydraulic proportional directional valve based on a helical proportional torque motor according to claim 9, characterized in that: The materials of the front cover (3), the zero adjustment nut (11) and the spring seat (13) are aluminum, and the material of the shell (4) is DT4C.

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