Multi-axis control-oriented dual-mode proportional servo valve giving consideration to high dynamic and large flow

Abstract

The invention relates to a dual-mode proportional servo valve oriented to multi-axis control and giving consideration to high dynamic and large flow. The dual-mode proportional servo valve comprises a valve body, a valve element, two end covers, two rigidity adjusting mechanisms, two proportional electromagnets, a Hall displacement sensor and a proportional servo controller. The two end covers, the rigidity adjusting mechanism and the proportional electromagnet are symmetrically arranged on the left side and the right side of the valve body, and the middle of the valve element is located in the valve body. The valve element is a non-circumferential opening sliding valve, a left stepped shaft part and a right stepped shaft part are arranged in the middle of the valve element, and a two-stage combined throttling groove with the through-flow area changing in the axial direction is formed in a shaft shoulder of the valve element. Rigidity adjusting mechanisms with adjustable spring rigidity are respectively arranged in the two end covers; the Hall displacement sensor monitors the displacement of the valve core in real time; and the proportional servo controller regulates and controls the output of the proportional servo valve according to the displacement feedback signal. According to the dual-mode proportional servo valve, two working modes of high-frequency fine adjustment and stable large flow are achieved through cooperative regulation and control of the through-flow area and the spring rigidity, and the dual-mode proportional servo valve adapts to various complex working conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of proportional servo valves, and particularly relates to a dual-mode proportional servo valve for multi-axis control that takes into account high dynamics and large flow rates. Background Art

[0002] Heavy multi-axis vehicles are core transport equipment required for major equipment and engineering construction, and are widely used in many fields such as the transportation of extra-long wind turbine blades, the transportation of ultra-heavy and large precast beams, and the all-road mobile deployment of intercontinental missiles. Among them, the steering system is a core component of the whole vehicle, and it must take into account the safety of high-speed driving on flat roads and the flexibility of low-speed cornering on narrow and rough mountain roads. Under the condition of high-speed driving on flat roads, even a small angular deviation will cause a significant lateral offset of the vehicle body, affecting driving stability. Therefore, the steering proportional servo valve needs to perform high-frequency and precise fine-tuning near the neutral position to improve the steering control speed and accuracy, and ensure the high-speed driving safety of heavy multi-axis vehicles. Under the condition of low-speed cornering on narrow and rough mountain roads, the steering resistance moment of the vehicle is large and varies widely, requiring the steering proportional servo valve to be able to provide a continuous and stable large flow rate output to support large and rapid angular adjustments, achieve highly maneuverable and flexible cornering, and thus improve the overall vehicle transportation efficiency.

[0003] However, the existing technical solutions of proportional servo valves do not fully consider the multi-condition requirements of heavy multi-axis vehicles, and it is difficult to simultaneously meet the dual performance requirements of high-frequency fine-tuning in the neutral position and continuous and stable large flow rate output. For example, patents such as CN113266613B, CN116146556A, and CN208295247U have achieved large flow rate output through shaft flow distribution and a two-stage amplification structure of a pilot-main valve. However, due to the mechanical inertia of the shaft flow distribution structure and the energy transfer lag from the pilot stage to the main stage, the response speed of the proportional valve is slow, and it cannot meet the high-frequency fine-tuning requirements in the neutral position. Patents such as CN113175454A, CN119491849A, CN2900886Y, and CN105545856B replace the proportional electromagnet with a servo motor. Although the response time of the control valve is shortened, due to the low power density of the servo motor, it cannot provide a continuous large flow rate output. These technical limitations indicate that there are still significant performance shortboards in the existing proportional servo valves under the complex conditions of heavy multi-axis vehicles, and it is urgent to break through the traditional design ideas to achieve high-performance control in the full range of working conditions. Summary of the Invention

[0004] The purpose of the present invention is to provide a dual-mode proportional servo valve for multi-axis control that takes into account high dynamics and large flow rates. This dual-mode proportional servo valve can take into account the high-frequency dynamic adjustment ability and stable large flow rate output characteristics, and can adapt to a variety of complex working conditions.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a dual-mode proportional servo valve for multi-axis control and taking into account both high dynamics and large flow, including a valve body, a valve core, two end covers, two stiffness adjustment mechanisms, two proportional electromagnets, a Hall displacement sensor and a proportional servo controller; The two end covers are symmetrically arranged on the left and right sides of the valve body, the two stiffness adjustment mechanisms are symmetrically arranged in the two end covers, the two proportional electromagnets are symmetrically arranged on the left side of the left end cover and on the right side of the right end cover, the middle part of the valve core is located in the valve body, the left and right ends of the valve core are respectively extended into the end covers and connected to the moving iron in the proportional electromagnet passing through the end covers, so as to drive the valve core to move through the moving iron; The valve core is a non-full-circumference opening sliding valve, and the middle part of the valve core has two raised stepped shaft parts on the left and right. A plurality of secondary combined throttling grooves are symmetrically opened along the circumferential direction on the left and right shaft shoulders of the stepped shaft parts, which are used to adjust the oil flow rate; each secondary combined throttling groove is composed of a first throttling groove away from the shaft shoulder and a second throttling groove close to the shaft shoulder connected along the axial direction, and the flow area of ​​the first throttling groove is smaller than the flow area of ​​the second throttling groove, and the axial lengths of the first throttling groove and the second throttling groove account for a% and 1-a% of the valve core stroke respectively, so that when the valve core displacement does not reach ±a% of the valve core stroke, the oil flow rate is adjusted with a small flow area, and when the valve core displacement reaches more than ±a% of the valve core stroke, the oil flow rate is adjusted with a large flow area; The two end covers are respectively provided with a stiffness adjustment mechanism, wherein the low stiffness spring in the stiffness adjustment mechanism is compressed during the entire displacement of the valve core, and the high stiffness spring is compressed only when the displacement of the valve core reaches more than ±a% of the valve core stroke; The Hall displacement sensor is connected to the moving iron of the proportional electromagnet on one side through a feedback rod to monitor the valve core displacement in real time; the proportional servo controller receives the displacement feedback signal of the Hall displacement sensor and regulates the output of the dual-mode proportional servo valve.

[0006] Furthermore, the proportional servo controller controls the output of the proportional solenoid according to the displacement feedback signal of the Hall displacement sensor to achieve dual-mode switching; the dual modes are a high-frequency fine-tuning mode and a stable large flow mode; when the valve core displacement does not reach ±a% of the valve core stroke, the dual-mode proportional servo valve is in the high-frequency fine-tuning mode, and the oil circuit flow is adjusted with a small flow area and only the low-rigidity spring in the stiffness adjustment mechanism is compressed to achieve linear flow regulation and ensure rapid dynamic response; when the valve core displacement reaches more than ±a% of the valve core stroke, the dual-mode proportional servo valve is in the stable large flow mode, and the oil circuit flow is adjusted with a large flow area and both the low-rigidity spring and the high-rigidity spring in the stiffness adjustment mechanism are compressed to achieve a large flow stable output.

[0007] Furthermore, the value of a is 25.

[0008] Furthermore, the second flow channel is a rectangular throttling groove extending axially from the shaft shoulder. The flow-through cross-section of the second throttling groove is rectangular and unchanged along the axial direction. The first throttling groove is a V-shaped throttling groove extending axially from the bottom of the second throttling groove. The flow-through cross-section of the first throttling groove is V-shaped and continuously decreases along the axial direction.

[0009] Furthermore, the opening angle of the V-shaped throttling groove is 45°, and the V-shaped throttling groove is connected to the rectangular throttling groove through a gradual transition.

[0010] Furthermore, there is an intermediate shaft section between the left and right stepped shaft parts of the spool. The diameter of the intermediate shaft section is smaller than that of the stepped shaft parts. One end of the stepped shaft part away from the intermediate shaft section is successively connected with a first shaft section, a second shaft section, and a third shaft section with gradually decreasing diameters. The end of the third shaft section is connected to the moving iron passing through the end cover in the proportional electromagnet.

[0011] Furthermore, the diameter of the inner wall of the valve body is adapted to the diameter of the stepped shaft part of the spool. Four annular grooves are successively formed on the inner wall of the valve body from left to right. The first annular groove and the fourth annular groove are connected through a U-shaped flow channel inside the valve body and are respectively opposite to the left and right first shaft sections of the spool, cooperating to form two left and right oil outlet annular oil cavities T. The second annular groove and the third annular groove are respectively opposite to the middle parts of the left and right stepped shaft parts of the spool, cooperating to form a control annular oil cavity A and a control annular oil cavity B. The intermediate shaft section of the spool and the valve body cooperate to form an oil inlet annular oil cavity P. The widths of the second annular groove and the third annular groove along the axial direction are equal to the distance between the bottoms of two secondary combined throttling grooves symmetrically arranged on the left and right shaft shoulders of the stepped shaft part. When the spool is in the middle position, that is, when there is no displacement, it is just not communicated with the secondary combined throttling grooves on the left and right sides. When the spool moves to the left, the oil inlet annular oil cavity P is communicated with the control annular oil cavity A, and the control annular oil cavity B is communicated with the oil outlet annular oil cavity T on the right side. When the spool moves to the right, the oil inlet annular oil cavity P is communicated with the control annular oil cavity B, and the control annular oil cavity A is communicated with the oil outlet annular oil cavity T on the left side.

[0012] Furthermore, the stiffness adjustment mechanism includes a low-stiffness spring, a high-stiffness spring, a low-stiffness spring seat, and a high-stiffness spring seat; the low-stiffness spring seat is installed on the outer periphery of the second shaft section and positioned on the shoulder of the first shaft section; the low-stiffness spring is sleeved between the outer periphery of the first shaft section and the inner periphery of the end cover, one end of the low-stiffness spring is connected to the valve core through the low-stiffness spring seat, and the other end is in contact with the inner end of the end cover; the high-stiffness spring seat is installed on the outer periphery of the third shaft section and positioned on the moving iron of the proportional electromagnet; the high-stiffness spring is sleeved between the outer periphery of the first shaft section and the inner side of the low-stiffness spring, one end of the high-stiffness spring is connected to the moving iron through the high-stiffness spring seat, and the other end is in contact with the shoulder of the second shaft section; when the displacement of the valve core is less than ±a% of the valve core stroke, the high-stiffness spring seat is not in contact with the end cover, and the valve core only compresses the low-stiffness spring; when the displacement of the valve core reaches more than ±a% of the valve core stroke, the high-stiffness spring seat is in contact with the end cover, and the valve core compresses both the low-stiffness spring and the high-stiffness spring simultaneously.

[0013] Furthermore, the proportional electromagnet includes a proportional electromagnet housing, a magnetic yoke, a magnetic isolation ring, a coil, and a moving iron. The magnetic yoke is arranged inside the proportional electromagnet housing, the coil is wound between the proportional electromagnet housing and the magnetic yoke, the magnetic isolation ring is arranged on the magnetic yoke, and the moving iron is arranged at the center of the magnetic yoke.

[0014] Furthermore, the Hall displacement sensor is installed on the proportional electromagnet housing of one side of the proportional electromagnet, and the Hall displacement sensor is connected to the moving iron through a feedback rod passing through the proportional electromagnet housing.

[0015] Compared with the prior art, the present invention has the following beneficial effects: (1) A dual-mode proportional servo valve is realized. This proportional servo valve realizes dual-mode switching based on the displacement of the valve core to meet the requirements of different steering working conditions. High-frequency fine-tuning mode (within ±a% of the valve core stroke): In this mode, through the collaborative design of a low-stiffness spring and a small flow area, the valve core movement resistance such as spring force and hydrodynamic force is significantly reduced, realizing high-frequency dynamic response, so as to meet the rapid and safe deviation correction requirements under the condition of high-speed driving on a flat road. Stable large-flow mode (above ±a% of the valve core stroke): When the displacement of the valve core exceeds ±a% of the valve core stroke, the proportional servo valve switches to the stable large-flow mode. This mode adopts a large flow area design to ensure sufficient flow output, and at the same time, it is combined with a high-stiffness spring to enhance the system stability and avoid the valve core instability phenomenon caused by the hydrodynamic force fluctuation under large flow, so as to provide continuous and stable large-flow output for the vehicle under the condition of narrow and rough mountain roads, ensuring fast and efficient cornering performance.

[0016] (2) A stiffness adjustment mechanism is implemented. The proportional servo valve arranges the stiffness adjustment mechanism on both the left and right sides of the spool to adapt to the spring force requirements in different working modes. This stiffness adjustment mechanism consists of a low-stiffness spring and a high-stiffness spring. Within the range of ±a% spool stroke, the spool movement only compresses the low-stiffness spring, corresponding to a small spring resistance generated, and the proportional servo valve has a fast response speed. When the spool is in the middle position, the distance between the high-stiffness spring seat and the end cover is ±a% of the spool stroke. When the spool displacement exceeds ±a% of the stroke, the high-stiffness spring seat contacts the end cover. At this time, the spool movement will compress both the low-stiffness spring and the high-stiffness spring simultaneously, thereby enhancing the stability of the spool under large strokes and preventing instability caused by hydraulic force fluctuations.

[0017] (3) A two-stage combined throttle groove is implemented. The proportional servo valve realizes the compatibility of high-frequency dynamic response and stable large-flow output through the design of the two-stage combined throttle groove. Within the range of ±a% spool stroke, the oil circuit flow is adjusted through the V-shaped throttle groove. This structure has a low hydraulic resistance and provides a highly linear flow adjustment ability under small displacements, meeting the requirements of high-frequency dynamic control. When the spool displacement exceeds ±a% of the stroke, the throttle groove structure switches to a rectangular throttle groove with a wide opening structure. This structure significantly increases the flow-through area and realizes the stable output of large flows. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of the dual-mode proportional servo valve according to an embodiment of the present invention; Figure 2 is a schematic structural diagram of the spool in an embodiment of the present invention; Figure 3 is a schematic structural diagram of the stiffness adjustment mechanism in an embodiment of the present invention; Figure 4 is a schematic diagram of the dual-mode proportional servo valve in the high-frequency fine-tuning mode according to an embodiment of the present invention; Figure 5 is a schematic diagram of the dual-mode proportional servo valve in the stable large-flow mode according to an embodiment of the present invention.

[0019] In the figure: 1 - proportional electromagnet housing; 2 - yoke; 3 - magnetic isolation ring; 4 - high-stiffness spring seat; 5 - low-stiffness spring; 6 - high-stiffness spring; 7 - low-stiffness spring seat; 8 - spool; 9 - valve body; 10 - moving iron; 11 - end cover; 12 - coil; 13 - feedback rod; 14 - Hall displacement sensor; 15 - proportional servo controller. Detailed Embodiments

[0020] The present invention will be further described below in conjunction with the drawings and embodiments.

[0021] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0022] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0023] like Figure 1 As shown, this embodiment provides a dual-mode proportional servo valve for multi-axis control and taking into account both high dynamics and large flow, including a valve body 9, a valve core 8, two end covers 11, two stiffness adjustment mechanisms, two proportional solenoids, a Hall displacement sensor 14 and a proportional servo controller 15.

[0024] The two end covers 11 are symmetrically arranged on the left and right sides of the valve body 9, the two stiffness adjustment mechanisms are symmetrically arranged in the two end covers 11, the two proportional electromagnets are symmetrically arranged on the left side of the left end cover and the right side of the right end cover, the middle part of the valve core 8 is located in the valve body 9, the left and right ends of the valve core 8 are respectively extended into the end covers 11 and connected to the moving iron 10 in the proportional electromagnet that passes through the end covers, so as to drive the valve core to move through the moving iron.

[0025] The valve core 8 is a non-full-circumferential opening sliding valve, and the middle part of the valve core 8 has two raised stepped shaft parts on the left and right. A plurality of secondary combined throttling grooves are symmetrically opened along the circumferential direction on the left and right shaft shoulders of the stepped shaft parts for adjusting the oil flow rate; each secondary combined throttling groove is composed of a first throttling groove away from the shaft shoulder and a second throttling groove close to the shaft shoulder connected along the axial direction, the flow area of ​​the first throttling groove is small and increases slowly with the displacement of the valve core, the flow area of ​​the second throttling groove is large and increases rapidly with the displacement of the valve core, the axial lengths of the first throttling groove and the second throttling groove account for a% and 1-a% of the valve core stroke respectively, so that the oil flow rate is adjusted with a small flow area when the valve core displacement does not reach ±a% of the valve core stroke, and the oil flow rate is adjusted with a large flow area when the valve core displacement reaches more than ±a% of the valve core stroke.

[0026] The two end covers 11 are respectively provided with a stiffness adjustment mechanism, in which the low stiffness spring 5 is compressed during the entire displacement of the valve core, and the high stiffness spring 6 is compressed only when the valve core displacement reaches more than ±a% of the valve core stroke; The Hall displacement sensor 14 is connected to the moving iron 10 of the proportional electromagnet on one side through the feedback rod 13 to monitor the spool displacement in real time; the proportional servo controller 15 receives the displacement feedback signal of the Hall displacement sensor 14 and precisely regulates the output of the dual-mode proportional servo valve.

[0027] The proportional servo controller 15 controls the output of the proportional electromagnet according to the displacement feedback signal of the Hall displacement sensor 14 to achieve dual-mode switching. The dual modes are the high-frequency fine-tuning mode and the stable large-flow mode. When the spool displacement does not reach ±a% of the spool stroke, the dual-mode proportional servo valve is in the high-frequency fine-tuning mode, as Figure 4 shown. In this mode, the oil flow of the oil circuit is regulated with a small flow area, and only the low-stiffness spring in the stiffness regulating mechanism is compressed to achieve linear flow regulation and ensure fast dynamic response. When the spool displacement reaches above ±a% of the spool stroke, the dual-mode proportional servo valve is in the stable large-flow mode, as Figure 5 shown. In this mode, the oil flow of the oil circuit is regulated with a large flow area, and both the low-stiffness spring and the high-stiffness spring in the stiffness regulating mechanism are compressed to achieve stable large-flow output. In this embodiment, a is taken as 25.

[0028] As Figure 2 shown, the second throttle groove is a rectangular throttle groove extending axially from the shaft shoulder, the flow cross-section of the second throttle groove is rectangular and unchanged axially, the first throttle groove is a V-shaped throttle groove extending axially from the bottom of the second throttle groove, and the flow cross-section of the first throttle groove is V-shaped and continuously decreases axially. In this embodiment, the opening angle of the V-shaped throttle groove is 45°, and the V-shaped throttle groove is connected to the rectangular throttle groove through a gradual transition.

[0029] There is an intermediate shaft section between the left and right stepped shaft parts of the spool 8. The diameter of the intermediate shaft section is smaller than that of the stepped shaft parts. One end of the stepped shaft part away from the intermediate shaft section is successively connected with a first shaft section, a second shaft section and a third shaft section with diameters decreasing in sequence. The end of the third shaft section is connected to the moving iron passing through the end cover in the proportional electromagnet.

[0030] The diameter of the inner wall of the valve body 9 is adapted to the diameter of the spool stepped shaft part; four annular grooves are successively opened on the inner wall of the valve body 9 from left to right. The first annular groove and the fourth annular groove are communicated through a U-shaped flow channel inside the valve body 9 and are respectively opposite to the left and right first shaft sections of the spool 8, and cooperate to form left and right oil outlet annular oil cavities T; the second annular groove and the third annular groove are respectively opposite to the middle parts of the left and right stepped shaft parts of the spool 8, and cooperate to form a control annular oil cavity A and a control annular oil cavity B; the intermediate shaft section of the spool 8 and the valve body 9 cooperate to form an oil inlet annular oil cavity P.

[0031] The axial widths of the second annular groove and the third annular groove are equal to the distance between the bottoms of two secondary combined throttle grooves symmetrically arranged on the left and right shoulders of the stepped shaft portion, so that when the spool 8 is in the middle position (without displacement), it is just not in communication with the secondary combined throttle grooves on the left and right sides; when the spool 8 moves to the left, the inlet annular oil chamber P is in communication with the control annular oil chamber A, and the control annular oil chamber B is in communication with the outlet annular oil chamber T on the right; when the spool 8 moves to the right, the inlet annular oil chamber P is in communication with the control annular oil chamber B, and the control annular oil chamber A is in communication with the outlet annular oil chamber T on the left.

[0032] As Figure 3 shown, the stiffness adjustment mechanism includes a low-stiffness spring 5, a high-stiffness spring 6, a low-stiffness spring seat 7 and a high-stiffness spring seat 4. The low-stiffness spring seat 7 is installed on the outer periphery of the second shaft section and positioned on the shoulder of the first shaft section. The low-stiffness spring 5 is sleeved between the outer periphery of the first shaft section and the inner periphery of the end cover 11. One end of the low-stiffness spring 5 is connected to the spool 8 through the low-stiffness spring seat 7, and the other end is in contact with the inner end of the end cover 11. The high-stiffness spring seat 4 is installed on the outer periphery of the third shaft section and positioned on the moving iron of the proportional electromagnet. The high-stiffness spring 6 is sleeved between the outer periphery of the first shaft section and the inside of the low-stiffness spring 5. One end of the high-stiffness spring 6 is connected to the moving iron 10 through the high-stiffness spring seat 4, and the other end is in contact with the shoulder of the second shaft section. When the displacement of the spool is less than ±a% of the spool stroke, the high-stiffness spring seat 4 is not in contact with the end cover 11, and the spool 8 only compresses the low-stiffness spring; when the displacement of the spool reaches more than ±a% of the spool stroke, the high-stiffness spring seat 4 is in contact with the end cover 11, and the spool 8 compresses both the low-stiffness spring and the high-stiffness spring at the same time.

[0033] The proportional electromagnet includes a proportional electromagnet housing 1, a magnetic yoke 2, a magnetic isolation ring 3, a coil 12 and a moving iron 10. The magnetic yoke 2 is arranged inside the proportional electromagnet housing 1. The coil 12 is wound between the proportional electromagnet housing 1 and the magnetic yoke 2. The magnetic isolation ring 3 is arranged on the magnetic yoke 2. The moving iron 10 is arranged at the center of the magnetic yoke 2.

[0034] The Hall displacement sensor is installed on the proportional electromagnet housing of one side of the proportional electromagnet. The Hall displacement sensor is connected to the moving iron through a feedback rod passing through the proportional electromagnet housing.

[0035] In the present invention, the dual-mode proportional servo valve can achieve two working modes, namely high-frequency fine adjustment (within ±25% of the spool stroke) and stable large flow rate (above ±25% of the spool stroke), through the coordinated regulation of spring stiffness and flow area. These two modes are respectively applicable to rapid deviation correction during high-speed driving on flat roads and efficient cornering on narrow and rugged mountain roads. Within the range of ±25% of the spool stroke, the movement of the spool only compresses the low-stiffness springs in the left and right stiffness adjustment mechanisms, and at the same time, the flow area formed by the V-shaped throttle groove and the valve body is small. At this stage, the movement resistance such as spring force and hydrodynamic force is small, and the proportional servo valve has a faster response speed. When the spool displacement exceeds ±25% of the spool stroke, the spool compresses both the low-stiffness springs and the high-stiffness springs in the left and right stiffness adjustment mechanisms, and the flow area formed by the rectangular throttle groove and the valve body is large. In this stage, the use of high-stiffness springs and large flow areas not only provides a larger output flow rate but also improves the stability of the spool under large hydrodynamic force fluctuations, enabling the proportional servo valve to output a stable large flow rate.

[0036] The stiffness adjustment mechanism provided in this embodiment can achieve spring stiffness adjustment within different spool displacement ranges. One end of the low-stiffness spring contacts the end cover, and the other end is connected to the low-stiffness spring seat, while the other end of the low-stiffness spring seat contacts the spool. When the spool moves, it will push the low-stiffness spring seat, thereby compressing the low-stiffness spring. One end of the high-stiffness spring contacts the spool shoulder, and the other end is connected to the high-stiffness spring seat, and the other end of the high-stiffness spring seat contacts the moving iron. When the spool is in the middle position, the distance between the high-stiffness spring seat and the end cover is 25% of the spool stroke. Within the range of ±25% of the spool stroke, the movement of the spool does not change the relative position between the high-stiffness spring seat and the spool and does not compress the high-stiffness spring. When the spool displacement exceeds ±25% of the stroke, the high-stiffness spring seat contacts the end cover. At this time, the movement of the spool not only compresses the low-stiffness spring but also further compresses the high-stiffness spring, thereby increasing the output spring stiffness of the stiffness adjustment mechanism.

[0037] The secondary combined throttling groove provided in this embodiment can switch the change rate of the flow area within different spool displacement ranges. The spool is designed with 4 shoulders, and the on-off of the PA, PB, AT, and BT oil circuits are respectively controlled through the clearance fit between the shoulders and the valve body. The spool shoulders are all non-full-circumference openings, and 4 secondary combined throttling grooves are evenly distributed on the spool shoulders for regulating the oil circuit flow rate. The secondary combined throttling groove is composed of a V-shaped throttling groove and a rectangular throttling groove. The axial length of the rectangular throttling groove accounts for 75% of the spool stroke, starting from the end of the shoulder, and its end is connected to the starting point of the V-shaped throttling groove, and a gradual transition design is adopted. The opening angle of the V-shaped throttling groove is 45°, and the axial length accounts for 25% of the spool stroke, and its end is aligned with the edge of the oil hole in the valve body. When the spool displacement is within the range of ±25% of the stroke, the V-shaped throttling groove and the valve body cooperate to form a small flow area, so that the proportional servo valve has low hydraulic force and high flow control accuracy. When the spool displacement exceeds ±25% of the stroke, the control throttling groove transitions from V-shaped to U-shaped, and the rectangular throttling groove and the valve body cooperate to form a large flow area, thereby providing a larger output flow. In addition, to ensure the smooth transition of the flow-rate - stroke characteristic curve, a gradual transition design is adopted at the connection between the V-shaped throttling groove and the rectangular throttling groove, effectively reducing the flow rate mutation and fluid impact.

[0038] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention in other forms. Any person skilled in the art may use the disclosed technical content to make changes or modifications into equivalent embodiments with equivalent changes. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the technical solution content of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A dual-mode proportional servo valve for multi-axis control that takes into account high dynamics and large flow rates, characterized in that, It includes a valve body, a valve core, two end covers, two stiffness adjustment mechanisms, two proportional electromagnets, a Hall displacement sensor, and a proportional servo controller; The two end covers are symmetrically arranged on the left and right sides of the valve body. The two stiffness adjustment mechanisms are symmetrically arranged inside the two end covers. The two proportional electromagnets are symmetrically arranged on the left side of the left end cover and the right side of the right end cover. The middle part of the valve core is located inside the valve body. The left and right ends of the valve core respectively extend into the end covers and are connected to the moving iron passing through the end covers in the proportional electromagnets, so as to drive the displacement of the valve core through the moving iron; The valve core is a non-full-circumference opening slide valve. The middle part of the valve core has a stepped shaft part with two protrusions on the left and right. A plurality of second-stage combined throttle grooves are symmetrically arranged along the circumferential direction on the left and right shoulders of the stepped shaft part for adjusting the oil flow rate; each second-stage combined throttle groove is composed of a first throttle groove far from the shoulder and a second throttle groove close to the shoulder connected axially. The flow-through area of the first throttle groove is smaller than that of the second throttle groove. The axial lengths of the first throttle groove and the second throttle groove account for a% and 1 - a% of the valve core stroke respectively, so as to adjust the oil flow rate with a small flow-through area when the valve core displacement does not reach ±a% of the valve core stroke, and adjust the oil flow rate with a large flow-through area when the valve core displacement reaches more than ±a% of the valve core stroke; Stiffness adjustment mechanisms are respectively arranged inside the two end covers. In the stiffness adjustment mechanism, the low-stiffness spring is compressed throughout the displacement of the valve core, and the high-stiffness spring is only compressed when the valve core displacement reaches more than ±a% of the valve core stroke; The Hall displacement sensor is connected to the moving iron of one side proportional electromagnet through a feedback rod to monitor the valve core displacement in real time; the proportional servo controller receives the displacement feedback signal of the Hall displacement sensor and controls the output of the dual-mode proportional servo valve.

2. The dual-mode proportional servo valve for multi-axis control and taking into account both high dynamics and large flow according to claim 1 is characterized in that: The proportional servo controller controls the output of the proportional electromagnet according to the displacement feedback signal of the Hall displacement sensor to achieve dual-mode switching; the dual modes are the high-frequency fine-tuning mode and the stable large-flow mode; when the valve core displacement does not reach ±a% of the valve core stroke, the dual-mode proportional servo valve is in the high-frequency fine-tuning mode, adjusting the oil flow rate with a small flow-through area and only the low-stiffness spring in the stiffness adjustment mechanism is compressed to achieve linear flow regulation and ensure fast dynamic response; when the valve core displacement reaches more than ±a% of the valve core stroke, the dual-mode proportional servo valve is in the stable large-flow mode, adjusting the oil flow rate with a large flow-through area and both the low-stiffness spring and the high-stiffness spring in the stiffness adjustment mechanism are compressed to achieve stable large-flow output.

3. The dual-mode proportional servo valve for multi-axis control and taking into account both high dynamics and large flow according to claim 1 is characterized in that: a is taken as 25.

4. The dual-mode proportional servo valve for multi-axis control and taking into account both high dynamics and large flow according to claim 1 is characterized in that: The second throttle groove is a rectangular throttle groove extending axially starting from the shoulder. The flow-through cross-section of the second throttle groove is rectangular and unchanged axially. The first throttle groove is a V-shaped throttle groove extending axially starting from the bottom of the second throttle groove. The flow-through cross-section of the first throttle groove is V-shaped and continuously decreases axially.

5. The dual-mode proportional servo valve for multi-axis control and taking into account both high dynamics and large flow according to claim 4, characterized in that: The opening angle of the V-shaped throttle groove is 45°, and the V-shaped throttle groove is connected to the rectangular throttle groove through a gradual transition.

6. The dual-mode proportional servo valve for multi-axis control and taking into account both high dynamics and large flow according to claim 1, characterized in that: There is an intermediate shaft section between the left and right stepped shaft parts of the valve core. The diameter of the intermediate shaft section is smaller than that of the stepped shaft parts. One end of the stepped shaft part far from the intermediate shaft section is successively connected with a first shaft section, a second shaft section and a third shaft section with gradually decreasing diameters. The end of the third shaft section is connected with the moving iron passing through the end cover in the proportional electromagnet.

7. The dual-mode proportional servo valve for multi-axis control and taking into account both high dynamics and large flow according to claim 6, characterized in that: The diameter of the inner wall of the valve body is adapted to the diameter of the stepped shaft part of the valve core; four annular grooves are successively formed in the inner wall of the valve body from left to right. The first annular groove and the fourth annular groove are communicated through a U-shaped flow passage inside the valve body and respectively face the left and right first shaft sections of the valve core, and cooperate to form two left and right oil outlet annular oil cavities T; the second annular groove and the third annular groove respectively face the middle parts of the left and right stepped shaft parts of the valve core, and cooperate to form a control annular oil cavity A and a control annular oil cavity B; the intermediate shaft section of the valve core and the valve body cooperate to form an oil inlet annular oil cavity P. The axial widths of the second annular groove and the third annular groove are equal to the distance between the bottoms of two secondary combined throttle grooves symmetrically arranged on the left and right shaft shoulders of the stepped shaft part, so that when the valve core is in the middle position, that is, when there is no displacement, it is just not communicated with the secondary combined throttle grooves on the left and right sides; when the valve core moves to the left, the oil inlet annular oil cavity P is communicated with the control annular oil cavity A, and the control annular oil cavity B is communicated with the oil outlet annular oil cavity T on the right; when the valve core moves to the right, the oil inlet annular oil cavity P is communicated with the control annular oil cavity B, and the control annular oil cavity A is communicated with the oil outlet annular oil cavity T on the left.

8. The dual-mode proportional servo valve for multi-axis control and taking into account both high dynamics and large flow according to claim 6, characterized in that: The stiffness adjustment mechanism includes a low-stiffness spring, a high-stiffness spring, a low-stiffness spring seat and a high-stiffness spring seat; the low-stiffness spring seat is installed on the outer periphery of the second shaft section and positioned on the shaft shoulder of the first shaft section; the low-stiffness spring is sleeved between the outer periphery of the first shaft section and the inner periphery of the end cover. One end of the low-stiffness spring is connected with the valve core through the low-stiffness spring seat, and the other end is in contact with the inner end of the end cover; the high-stiffness spring seat is installed on the outer periphery of the third shaft section and positioned on the moving iron of the proportional electromagnet; the high-stiffness spring is sleeved between the outer periphery of the first shaft section and the inner side of the low-stiffness spring. One end of the high-stiffness spring is connected with the moving iron through the high-stiffness spring seat, and the other end is in contact with the shaft shoulder of the second shaft section; when the displacement of the valve core is less than ±a% of the valve core stroke, the high-stiffness spring seat is not in contact with the end cover, and the valve core only compresses the low-stiffness spring; when the displacement of the valve core reaches more than ±a% of the valve core stroke, the high-stiffness spring seat is in contact with the end cover, and the valve core compresses the low-stiffness spring and the high-stiffness spring at the same time.

9. The dual-mode proportional servo valve for multi-axis control and taking into account both high dynamics and large flow according to claim 6, characterized in that: The proportional electromagnet includes a proportional electromagnet housing, a magnetic yoke, a magnetic isolation ring, a coil and a moving iron. The magnetic yoke is arranged inside the proportional electromagnet housing. The coil is wound between the proportional electromagnet housing and the magnetic yoke. The magnetic isolation ring is arranged on the magnetic yoke. The moving iron is arranged at the center of the magnetic yoke.

10. The dual-mode proportional servo valve for multi-axis control and taking into account both high dynamics and large flow according to claim 9, characterized in that: The Hall displacement sensor is installed on the proportional electromagnet housing of one side proportional electromagnet. The Hall displacement sensor is connected with the moving iron through a feedback rod passing through the proportional electromagnet housing.

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