Main valve element and proportional flow servo valve

Abstract

The invention relates to a main valve element and a proportional flow servo valve. The main valve element comprises a valve element body extending in the X-axis direction, and a stepped throttling groove is formed in the valve element body; the throttling grooves at least comprise the first throttling groove and the second throttling groove. Wherein the first throttling groove and the second throttling groove communicate with each other and are distributed in the X-axis direction, and a step is formed in the communicating position of the first throttling groove and the second throttling groove; the size of the first throttling groove and the size of the second throttling groove are sequentially increased. According to the stepped multi-stage throttling groove formed in the main valve element, the problem that traditional single-caliber flow suddenly rises can be avoided through the stepped communicating step structure with the size sequentially increased, and the full-range stable transition and precise adaptation of the flow from low to high are achieved; and therefore, the operation reliability of the proportional flow servo valve and the control precision of the hydraulic control system are guaranteed.

Description

Technical Field

[0001] This disclosure relates to the field of hydraulics, specifically to a main valve core and a proportional flow servo valve. Background Technology

[0002] The main valve core is a key component of the hydraulic control system. Current technology primarily uses a single throttling groove design, but this has several significant drawbacks: the flow area of ​​a single throttling groove has a fixed nonlinear relationship with the valve core displacement, resulting in slow flow rate changes at low openings and a sudden increase in flow rate at high openings. This leads to insufficient control accuracy over a large flow range and requires complex compensation algorithms; otherwise, it is prone to oscillation and inaccuracy. Furthermore, it has poor cavitation resistance; the sudden increase in flow velocity when fluid flows through it triggers cavitation, and the collapse of bubbles erodes the valve core surface, also generating pressure pulsations, vibrations, and noise, disrupting flow continuity. Finally, it suffers from insufficient operational reliability; contaminants can easily get stuck in the precise fit between the valve core and the valve sleeve, causing jamming. Additionally, the large closing force generated when opening a large single-diameter valve hinders rapid valve core movement. Therefore, there is an urgent need to improve the throttling structure to solve these problems. Summary of the Invention

[0003] This disclosure provides a main valve core and a proportional flow servo valve to address the problems existing in the prior art.

[0004] According to a first aspect of this disclosure, a main valve core is provided, including a valve core body extending along an X-axis direction, wherein a stepped throttling groove is provided on the valve core body; the throttling groove is configured to include at least a first throttling groove and a second throttling groove; wherein the first throttling groove and the second throttling groove are interconnected and configured to be distributed in the X-axis direction, and a step is formed at the position where the first throttling groove and the second throttling groove are connected; wherein the dimensions of the first throttling groove and the second throttling groove are configured to increase sequentially.

[0005] In one embodiment of this disclosure, the radial depth of the second throttling groove on the valve core body is greater than the radial depth of the first throttling groove, and the difference in radial depth between the first throttling groove and the second throttling groove constitutes the height of the step.

[0006] In one embodiment of this disclosure, a plurality of throttling grooves are provided at intervals in the circumferential direction of the valve core body.

[0007] In one embodiment of this disclosure, the valve core body is provided with annular shoulders spaced at intervals along the X-axis direction, and the throttling grooves are respectively provided on opposite axial sides of the shoulders.

[0008] In one embodiment of this disclosure, the throttling groove is configured to be triangular, arc-shaped, or trapezoidal.

[0009] According to a second aspect of this disclosure, a proportional flow servo valve is also provided, including a main valve body, the main valve body comprising: The main valve seat is configured to have a main valve chamber, and the main valve seat is provided with an oil inlet and an oil outlet communicating with the main valve chamber; According to the above-mentioned main valve core, the main valve core is movably connected in the main valve cavity and is configured to enable the first throttling groove and the second throttling groove to be sequentially connected to the oil outlet during movement.

[0010] In one embodiment of this disclosure, the oil outlet includes a first working oil port and a second working oil port, and the main valve core is configured to move along the X-axis to selectively connect the oil inlet to the first working oil port or the passage between the oil inlet and the second working oil port through a corresponding throttling groove.

[0011] In one embodiment of this disclosure, the positions of the main valve chamber located at opposite ends of the main valve core are respectively referred to as the first control chamber and the second control chamber; The proportional flow servo valve includes a pilot valve, which includes a pilot valve seat and a pilot valve core. The pilot valve seat is configured to have a pilot valve cavity that mates with the pilot valve core, and a first pilot oil outlet, a second pilot oil outlet, and a pilot oil inlet that communicate with the pilot valve cavity. The first pilot oil outlet is configured to communicate with a first control cavity, and the second pilot oil outlet is configured to communicate with a second control cavity. The proportional flow servo valve includes a proportional electromagnet, and the pilot valve core is configured to be controlled by the proportional electromagnet to move to a passage connecting the pilot oil inlet to a first pilot oil outlet, or the pilot oil inlet to a second pilot oil outlet.

[0012] In one embodiment of this disclosure, the proportional flow servo valve includes a detection unit configured to include a detection rod extending into the first control chamber and cooperating with the main valve core, the detection unit being configured to detect the displacement of the main valve core via the detection rod.

[0013] In one embodiment of this disclosure, the proportional electromagnet includes a control rod connected to the pilot valve core; a manual unit is provided at one end of the proportional electromagnet away from the pilot valve core, the manual unit including a base with an inner cavity, a manual adjustment rod located within the base, and a cover plate sealing the inner cavity is provided on the outer end face of the base; the manual adjustment rod is configured to cooperate with the control rod to drive the pilot valve core to move via the control rod.

[0014] One beneficial effect of this disclosure is that the main valve core and proportional flow servo valve provided herein include a valve core body extending along the X-axis, on which a stepped throttling groove is provided; the throttling groove includes at least a first throttling groove and a second throttling groove; wherein the first throttling groove and the second throttling groove are interconnected and distributed in the X-axis direction, forming a step at the connection point; the dimensions of the first throttling groove and the second throttling groove are constructed to increase sequentially. Through the stepped interconnection structure of the throttling grooves with sequentially increasing dimensions, the problem of sudden flow jumps in traditional single-diameter flow rates can be avoided, achieving a smooth transition and precise adaptation of flow rates across the entire range from low to high. Simultaneously, cavitation cavitation is suppressed, the linearity and dynamic response of flow regulation are improved, and pressure loss is reduced, thereby ensuring the operational reliability of the proportional flow servo valve and the control accuracy of the hydraulic control system.

[0015] Other features and advantages of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the present disclosure and, together with their description, serve to explain the principles of the present disclosure.

[0017] Figure 1 This is a cross-sectional schematic diagram of the main valve core provided in this disclosure; Figure 2 This is a schematic diagram of the main valve core provided in this disclosure; Figure 3 This is a cross-sectional schematic diagram of the proportional flow servo valve provided in this disclosure; Figure 4 This is a cross-sectional schematic diagram of the proportional flow servo valve provided in this disclosure; Figure 5 This is a partial structural diagram of the proportional flow servo valve disclosed herein.

[0018] Figures 1 to 5 The one-to-one correspondence between the component names and the reference numerals in the figures is as follows: 100. Proportional flow servo valve; 200. Main valve body; 201. First control chamber; 202. Second control chamber; 20. Main valve core; 21. Throttling groove; 211. First throttling groove; 212. Second throttling groove; 213. Step; 22. Shoulder; 23. Main valve seat; 24. Main valve chamber; 25. Oil inlet; 26. Oil outlet; 261. First working oil port; 262. Second working oil port; 300. Pilot valve; 30. Pilot valve seat; 31. Pilot valve core; 33. First pilot oil outlet; 34. Second pilot oil outlet; 35. Proportional electromagnet; 351. Control lever; 36. Manual unit; 361. Manual adjustment lever; 362. Base; 363. Cover plate; 400. Detection unit; 401. Detection lever. Detailed Implementation

[0019] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.

[0020] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use.

[0021] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0022] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0023] In this article, terms such as "up," "down," "front," "back," "left," and "right" are used only to indicate the relative positional relationship between related parts, rather than to define the absolute position of these related parts.

[0024] In this article, "first," "second," etc., are used only to distinguish one another, and not to indicate degree of importance, order, or prerequisite for each other.

[0025] In this document, terms such as “equal” and “same” are not strict mathematical and / or geometric limitations, but also include errors that are understandable to those skilled in the art and permissible in manufacturing or use.

[0026] This disclosure provides a main valve core and a proportional flow servo valve. The main valve core includes a valve core body extending along the X-axis, on which stepped throttling grooves are provided. The throttling grooves include at least a first throttling groove and a second throttling groove. The first and second throttling grooves are interconnected and distributed along the X-axis, forming a step at the connection point. The dimensions of the first and second throttling grooves are configured to increase sequentially. The stepped multi-stage throttling grooves on the main valve core of this disclosure, through the stepped interconnection structure with progressively increasing dimensions, can avoid the problem of sudden flow jumps in traditional single-diameter valves, achieving a smooth transition and precise adaptation of flow from low to high across the entire range. Simultaneously, it suppresses cavitation cavitation, improves the linearity and dynamic response of flow regulation, and reduces pressure loss, thereby ensuring the operational reliability of the proportional flow servo valve and the control accuracy of the hydraulic control system.

[0027] The specific embodiments of this disclosure are described below with reference to the accompanying drawings.

[0028] In traditional hydraulic valves, the flow area of ​​the throttling orifice changes in a fixed pattern during valve core movement. For example, the flow area of ​​a typical triangular groove exhibits a quadratic curve relationship with displacement. This results in slow flow rate changes at low opening degrees and extremely rapid flow rate changes at high opening degrees, making it difficult to achieve smooth and precise flow control throughout the entire stroke. This is particularly problematic in systems requiring control over a large flow range, where a single flow pattern often proves insufficient.

[0029] refer to Figure 1 and Figure 2 This disclosure provides a main valve core 20, including a valve core body extending along the X-axis direction. A stepped throttling groove 21 is provided on the valve core body, the throttling groove 21 including at least a first throttling groove 211 and a second throttling groove 212. The first throttling groove 211 and the second throttling groove 212 are interconnected and distributed along the X-axis direction, forming a step 213 at the point where the first throttling groove 211 and the second throttling groove 212 connect. The dimensions of the first throttling groove 211 and the second throttling groove 212 increase sequentially.

[0030] like Figure 2 As shown, the main valve core 20 adopts a stepped throttling groove 21 design. The flow channel curve is optimized through CFD simulation, reducing pressure loss by 15% and achieving a maximum flow rate of 460 L / min, a 9.5% improvement over Rexroth 4WRLE32. The valve core body is made of ductile iron QT600-3, with internal flow channels precision cast to a dimensional tolerance of ±0.05mm, reducing eddy current losses. The main valve core 20 uses a zinc-nickel alloy coating, improving salt spray resistance by 100%, adapting to high humidity and high salt environments, and extending the maintenance cycle from 3 months to 5 years. The valve core body has at least two stages of stepped throttling grooves 21 distributed along the X-axis. Each stage of the throttling grooves 21 is interconnected, forming a step 213 structure at the connection point, with its dimensions increasing sequentially along the positive displacement direction of the main valve core 20.

[0031] The first throttling groove 211 is a low-flow, high-precision throttling groove. When the main valve core 20 first begins to move, the flow is mainly carried out by the first throttling groove 211, which is responsible for achieving fine micro-flow control. As the main valve core 20 continues to move, larger throttling grooves 21 are required to work in sequence. Each stage of throttling groove 21 is specifically optimized for a specific flow range. The main valve core 20 provided in this disclosure contains at least two stages of throttling grooves 21 distributed in a stepped manner along the X-axis direction of the main valve core 20, with the specifications of the second and subsequent stages of throttling grooves 21 increasing sequentially. Under low-flow conditions, when the main valve core 20 only needs to make a slight movement, the first throttling groove 211 can stably output a small flow rate without the risk of "spurt" or "loss of control". Under high-flow conditions, when the main valve core 20 needs to move quickly, the subsequent stages of throttling grooves 21 open sequentially, and the flow cross-sections of each stage of throttling groove 21 overlap to form a continuously increasing total flow area, which together provides a huge flow area to meet the high flow rate requirements. Since the dimensions of the first throttling channel 211 and the second throttling channel 212 increase sequentially, the dimensions of subsequent throttling channels 21 are also specially designed to increase sequentially, avoiding the problem of sudden flow jump at a certain opening point in traditional single-diameter channels, and achieving a smooth transition and precise adaptation across the entire range "from low to high".

[0032] The steps 213 are continuously distributed along the circumference of the valve core body and can be designed as right-angle steps or rounded transition steps according to actual working conditions. In terms of position, the steps 213 are located at the axial connection between the first throttling groove 211 and the second throttling groove 212, and are coaxially arranged with the two-stage throttling grooves 21 to ensure that the flow direction of the fluid does not change drastically when it flows through the steps 213.

[0033] The beneficial effect of the right-angle step is that it can clearly divide the flow range of the two-stage throttling channel 21 and enhance the structural rigidity, while the rounded transition step can further reduce the flow channel resistance and avoid the fluid from generating impact loss at the step 213. The two structural forms can be flexibly adapted according to different pressure levels and flow requirements, and are not limited here.

[0034] In one embodiment of this disclosure, the radial depth of the second throttling groove 212 on the valve core body is greater than the radial depth of the first throttling groove 211, and the difference in radial depth between the first throttling groove 211 and the second throttling groove 212 constitutes the height of the step 213. Specifically, as... Figure 2As shown, the height of the step 213 can be the radial depth difference between two adjacent throttling grooves 21. It is worth noting that the radial depth difference between each pair of adjacent throttling grooves 21 can be different. In practical applications, the hydraulic system has different requirements for flow regulation. Different operating conditions may require different flow change rates. For example, in the low flow range, higher regulation accuracy is required to achieve fine control of the operating conditions, while in the high flow range, the flow switching speed needs to be accelerated to improve the system response efficiency. By setting different radial depth differences, the throttling area change rate when adjacent throttling grooves 21 are connected can be adapted to the usage requirements of the corresponding flow range. At the same time, the depth parameters of each throttling groove 21 can be flexibly optimized according to the design requirements of system pressure loss, anti-cavitation performance and other indicators, so as to take into account regulation accuracy, response speed and system operation stability, and broaden the applicable scenarios of valve core.

[0035] In one embodiment of this disclosure, the throttling groove 21 is configured in the shape of a triangle, an arc, or a trapezoid. For example, a triangular throttling groove may gradually narrow or widen in width from the opening to the bottom along the X-axis; the center of an arc-shaped throttling groove may be located in the X-axis direction or radially outward of the valve core body, with a uniform opening width; the upper base width of a trapezoidal throttling groove is smaller than the lower base width, and the inclination angle of the waist side relative to the axial direction is not limited. Throttling grooves 21 of different shapes all extend along the X-axis direction of the valve core body, with the opening flush with the outer circular surface of the valve core, and the bottom of the groove communicating with the main flow channel inside the valve core through radial depth. The shape of the throttling grooves 21 on the same shoulder 22 remains consistent, and different shoulders 22 can adopt a combination design of throttling grooves 21 of different shapes according to flow regulation requirements. The shape of the throttling groove 21 of the main valve core 20 provided in this disclosure includes, but is not limited to, the above three shapes.

[0036] Among them, the triangular throttling groove has the advantage of high flow regulation sensitivity in the small flow range, which can achieve precise micro-flow control; the arc-shaped throttling groove has a smooth flow channel and low fluid flow resistance, which can reduce pressure loss and improve flow efficiency under high flow conditions; the trapezoidal throttling groove takes into account both flow regulation range and control accuracy, and is suitable for scenarios with high requirements for flow linearity. The selection of various throttling groove shapes 21 allows the main valve core 20 to adapt to different hydraulic system requirements.

[0037] By adjusting the shape, width, and depth of each throttling groove 21, the flow curve passing through each throttling groove 21 can be controlled to approach a straight line. Each throttling groove 21 is responsible for "correcting" the slope of the flow curve within a certain range. The combined effect of multiple throttling grooves 21 ultimately makes the overall flow curve of the throttling grooves 21 on the main valve core 20 closer to an ideal straight line than the traditional single throttling method. The advantage of this design is that when the flow through the throttling grooves 21 on the main valve core 20 can be linearly adjusted, if the control system issues a one-unit command, the flow through the main valve core 20 will also increase by one unit. In this case, the algorithm of the control system will be simpler, more accurate, and more stable. If it is non-linear (for example, if the traditional single throttling groove 21 initially moves 1 mm, the flow rate changes by 1 L / min; then moves another 1 mm, the flow rate changes to 10 L / min), a very complex compensation algorithm is required, and it is very easy to produce oscillations or inaccurate control.

[0038] Therefore, by means of multi-stage throttling grooves 21, a very large total flow area can be provided without significantly increasing the size of the main valve core 20, simply by adjusting the radial depth or shape of each stage of throttling grooves 21, to meet the needs of large flow systems.

[0039] In one embodiment of this disclosure, such as Figure 2 As shown, multiple throttling grooves 21 are spaced apart in the circumferential direction of the valve core body. For example, 3-6 throttling grooves 21 are evenly distributed in the circumferential direction of the valve core body, and the interval angle between two adjacent throttling grooves 21 is 60-120°. The structural parameters (e.g., shape, width, depth) of each throttling groove 21 can be kept consistent. The groove openings of the throttling grooves 21 form evenly distributed openings on the outer circular surface of the main valve core 20. The bottom of the groove can be connected to the inside of the valve core through independent radial through holes, so that the fluid from multiple throttling grooves 21 is converged and introduced into the oil passage of the main valve core 20.

[0040] The beneficial effects of this structure are that the simultaneous flow through multiple throttling grooves 21 can significantly increase the total flow area, easily meeting the needs of large flow systems; the uniformly distributed design in the circumferential direction ensures that the main valve core 20 is subjected to balanced forces during operation, avoiding valve core wear caused by unilateral fluid pressure and improving the smoothness of valve core movement; at the same time, the reserved valve core body structure can ensure sufficient rigidity and prevent the strength reduction caused by excessive slotting.

[0041] In one embodiment of this disclosure, annular shoulders 22 are spaced apart along the X-axis on the valve core body, and throttling grooves 21 are respectively disposed on opposite axial sides of the shoulders 22. Figure 2As shown, the annular shoulder 22 is integrally formed with the valve core body. Several shoulders 22 are evenly spaced along the X-axis. Throttling grooves 21 are respectively set on opposite sides of the shoulders 22 along their axial direction, achieving isolation through the shoulders 22. The annular shoulder 22 serves as both the mounting carrier for the throttling grooves 21 and provides sealing and guiding functions, improving the fitting accuracy. The placement of the throttling grooves 21 on both sides of the shoulder 22 prevents different oil circuits from interfering with each other, reducing flow fluctuations caused by crossflow. At the same time, the cooperation of multiple shoulders 22 and multi-stage throttling grooves 21 can further refine the flow range, making flow regulation more precise.

[0042] In practical applications, hydraulic oil inevitably contains tiny solid contaminant particles. In traditional spool valves, there is a precise cylindrical fit clearance between the valve core and the valve sleeve. If particles happen to get stuck in this tiny gap, it will cause the valve core to "stick," resulting in malfunction, which is one of the most common failures in hydraulic systems.

[0043] The main valve core 20 provided in this disclosure has a stepped multi-stage throttling groove 21 on the shoulder 22, thus forming a groove on the surface of the shoulder 22. When particulate matter approaches the mating gap, the high-speed flowing fluid can more easily carry it in and flush it through these open grooves, rather than forcibly squeezing it into the sealing gap.

[0044] Meanwhile, traditional sharp-edged throttling orifices easily trap particulate matter. The stepped throttling groove 21, however, has a wider flow channel and a higher tolerance for particles. Even if a few particles are trapped in a certain stage of the throttling groove 21 on the shoulder 22, because the particles are not stuck in the mating clearance of the main valve core 20, the main valve core 20 can still move normally under the push of other unstuck areas, maintaining its operational flexibility. During the movement of the main valve core 20, particles that were originally stuck may also be flushed away by the fluid.

[0045] In a traditional hydraulic system, when fluid flows through the throttling groove 21, the flow velocity increases significantly, and according to Bernoulli's equation, the pressure drops sharply. If the pressure is lower than the saturated vapor pressure of the liquid at that temperature, the liquid will vaporize, forming a large number of bubbles (i.e., cavitation). When these bubbles flow with the fluid to the downstream high-pressure area, they will collapse rapidly, generating extremely high local impact pressures, which can reach thousands of atmospheres. This is the phenomenon of cavitation.

[0046] The hazards of cavitation are mainly manifested in several aspects: the shock waves generated by bubble collapse will repeatedly act on the surface of metal components such as valve cores and valve sleeves, causing material erosion damage and affecting the structural integrity of the components; in addition, the generation and collapse of a large number of bubbles will cause system pressure pulsation and mechanical vibration, accompanied by high-frequency noise, affecting the system's operational stability and environmental comfort; at the same time, cavitation will also disrupt the continuity of fluid flow, leading to flow fluctuations, and in severe cases, forming blocked flow, causing flow loss of control, thereby reducing the system's control accuracy and working efficiency.

[0047] In one specific embodiment of this disclosure, the main valve core 20 provides transforms a single large pressure surge into a continuous small pressure decrease process by setting multiple consecutive throttling grooves 21. Its core lies in a step-by-step pressure reduction mechanism: the fluid first experiences a partial pressure reduction at the first throttling groove 211, then enters the cavity between adjacent throttling grooves, where the pressure briefly recovers and tends to stabilize before flowing through the second throttling groove 212 and subsequent throttling grooves 21 to complete the gradual pressure reduction. By controlling the pressure reduction of each throttling groove 21 within a reasonable range, this disclosure effectively reduces the risk of local pressure falling below the saturated vapor pressure of the liquid at the corresponding temperature, suppressing cavitation at its source. The significant reduction in cavitation further greatly reduces system pressure pulsation and vibration noise, ensuring the stability and quietness of system operation.

[0048] The stepped throttling groove 21 of the main valve core 20 disclosed herein decomposes the single, drastic throttling process into multiple, gentle, and coordinated sub-processes, thereby achieving a comprehensive and significant improvement in several key performance indicators such as control accuracy, hydraulic stability, system response, and structural reliability. Therefore, it can be widely applied in proportional valves and servo valves.

[0049] In hydraulic servo control systems, high-frequency response proportional valves, as core components for electro-hydraulic conversion and power amplification, are widely used in high-end fields such as aerospace launch, metallurgical processing, and precision manufacturing. Among existing technologies, high-frequency response valves, represented by the German and American Moog G66 series, have formed a mature product system. Their basic structure includes a pilot control valve, a main valve, and an integrated electronic control module, achieving precise regulation of flow and pressure through closed-loop electrical signal control. However, existing technologies still have shortcomings in response speed, environmental adaptability, control accuracy, and reliability.

[0050] This disclosure also provides a proportional flow servo valve 100, such as Figure 3 As shown, the servo valve includes a main valve body 200, which serves as the supporting foundation and mounting carrier for the entire servo valve and is integrally forged. The main valve body 200 includes a main valve seat 23, which has a main valve cavity 24. The main valve seat 23 is provided with an oil inlet 25 and an oil outlet 26 communicating with the main valve cavity 24. The main valve cavity 24 can be a precision cylindrical hole located at the center of the main valve seat 23 to ensure the fitting accuracy with the main valve core 20. In addition to the oil inlet 25 and oil outlet 26 communicating with the main valve cavity 24, the main valve seat 23 is also provided with oil inlet channels and oil outlet channels respectively communicating with the oil inlet 25 and oil outlet 26. Optionally, a spring reset mechanism is configured inside the main valve cavity 24 for the main valve core 20, which automatically returns to the neutral position when power is off, ensuring system safety.

[0051] According to the main valve core 20 provided in the first aspect of this disclosure, the main valve core 20 is movably connected within the main valve chamber 24, and during its movement, it enables the first throttling groove 211 and the second throttling groove 212 to sequentially communicate with the oil outlet 26. For example... Figure 3 As shown, the main valve core 20 can reciprocate along the X-axis within the main valve chamber 24. Assuming that when the main valve core 20 moves along the positive X-axis, the first throttling groove 211 and the oil outlet channel corresponding to the oil outlet 26 begin to overlap and connect. As the displacement of the main valve core 20 increases, the opening of the first throttling groove 211 gradually increases, and the flow area increases linearly. The main valve core 20 continues to move until the second throttling groove 212 begins to overlap and connect with the oil outlet channel. Subsequent throttling grooves 21 open sequentially according to the increasing displacement of the main valve core 20, until the maximum stroke is reached, achieving full flow control of the main valve core 20. The design of the multi-stage throttling grooves 21 opening sequentially according to displacement ensures a smooth transition of flow from low to high, avoiding the sudden flow problems caused by traditional single throttling grooves 21. In this embodiment, the main valve body 200, main valve core 20, and main valve seat 23 together constitute a high-flow-rate slide valve, driven by pilot oil pressure, controlling the opening and closing and direction of the main oil circuit.

[0052] In one embodiment of this disclosure, the oil outlet 26 includes a first working oil outlet 261 and a second working oil outlet 262. The main valve core 20 is configured to move along the X-axis to selectively connect the oil inlet 25 to the first working oil outlet 261, or the oil inlet 25 to the second working oil outlet 262, through a corresponding throttling groove 21. Specifically, as Figure 3 As shown, the first working port 261 and the second working port 262 are symmetrically distributed on both radial sides of the main valve body 200. When the main valve core 20 moves along the positive X-axis, the throttling groove 21 on the shoulder 22 of the main valve core 20 selectively connects with the first oil outlet channel corresponding to the first working port 261. The hydraulic oil in the inlet 25 flows into the first working port 261 through the main valve core 20, driving the actuator to move. When the main valve core 20 moves in the reverse direction along the X-axis, the connection relationship is reversed. The hydraulic oil in the inlet 25 flows into the second working port 262 through the corresponding throttling groove 21, driving the actuator to move in the reverse direction. When the main valve core 20 is in the neutral position, all throttling grooves 21 are not connected with the working ports, and the oil circuit of the main valve core 20 is in a cut-off state. In addition, sealing rings are provided at the interfaces of the first working oil port 261 and the second working oil port 262. The sealing rings are made of fluororubber, which can withstand high pressure and high temperature, ensure sealing performance, prevent oil leakage, and have a temperature range of -40℃ to 200℃.

[0053] In one embodiment of this disclosure, the pilot oil in the pilot control oil circuit is used to drive the main valve core 20, and its supply and return methods are very flexible. The main power oil circuit is responsible for driving the actuator. When oil supply is required, pressurized oil comes from the system pump and enters the main valve core 20 through the oil inlet 25. Its working oil circuit is as follows: depending on the position of the main valve core 20, the pressurized oil flows from the oil inlet 25 to the first working oil port 261 or the second working oil port 262, driving the actuator to move. When oil return is required, the main valve body 200 is also provided with at least two return oil ports, and the oil on the other side of the actuator flows back to the main valve core 20 from the corresponding oil port (first working oil port 261 or second working oil port 262) and returns to the oil tank through the return oil port.

[0054] In one embodiment of this disclosure, reference is made to Figure 3 The positions of the main valve chamber 24 at opposite ends of the main valve core 20 are respectively designated as the first control chamber 201 and the second control chamber 202. The first control chamber 201 and the second control chamber 202 are cavities respectively located at opposite ends of the main valve chamber 24, and are coaxially arranged with the main valve chamber 24. Figures 3 to 5 The proportional flow servo valve 100 includes a pilot valve 300, which comprises a pilot valve seat 30 and a pilot valve core 31. The pilot valve seat 30 has a pilot valve cavity that mates with the pilot valve core 31, and a first pilot oil outlet 33, a second pilot oil outlet 34, and a pilot oil inlet communicating with the pilot valve cavity. The pilot valve core 31 is movably connected within the pilot valve cavity of the pilot valve seat 30. The precision fit between the pilot valve cavity and the pilot valve core 31 is controlled within ±0.05mm in dimensional tolerance, allowing the pilot valve core 31 to reciprocate linearly along its axis. The pilot valve 300 may be made of the same material as the main valve core 20 and the main valve seat 23, and may feature a zinc-nickel alloy coating to improve 100% salt spray resistance and extend maintenance intervals.

[0055] The first pilot oil outlet 33 is connected to the first control chamber 201, and the second pilot oil outlet 34 is configured to connect to the second control chamber 202. Figure 3 As shown, the first pilot oil outlet 33 is connected to the first control chamber 201 via an oil passage located inside the main valve seat 23 or via a high-pressure hose; the second pilot oil outlet 34 is connected to the second control chamber 202 via another oil passage located inside the main valve seat 23 or via another high-pressure hose; ensuring that the pilot valve core 31 can reliably switch oil passages when it moves. The oil pressure of the first pilot oil outlet 33 can be transmitted to the first control chamber 201, and the oil pressure of the second pilot oil outlet 34 can be transmitted to the second control chamber 202; since the first control chamber 201 and the second control chamber 202 are cavities located at opposite ends of the main valve chamber 24, the main valve core 20 can be displaced along the X-axis under the pressure difference force of the first control chamber 201 and the second control chamber 202.

[0056] The proportional flow servo valve 100 includes a proportional solenoid 35. A pilot valve core 31 is controlled by the proportional solenoid 35 to move to a passage connecting the pilot oil inlet to the first pilot oil outlet 33, or the pilot oil inlet to the second pilot oil outlet 34. Specifically, as shown... Figure 5 As shown, the proportional electromagnet 35 and the pilot valve core 31 are coaxially arranged. Both ends of the pilot valve core 31 can be equipped with return springs. When there is no current input to the proportional electromagnet 35, the return springs push the pilot valve core 31 back to the neutral position. At this time, all oil ports are not connected, and the pilot oil circuit is in a closed state. When an electrical signal is input to the proportional electromagnet 35, the proportional electromagnet 35 pushes the pilot valve core 31 to overcome the elastic force of the return springs, moving it to the passage connecting the pilot oil inlet to the first pilot oil outlet 33, or the pilot oil inlet to the second pilot oil outlet 34.

[0057] In one specific embodiment of this disclosure, a high-thrust proportional electromagnet 35 with a precision fit clearance design is adopted, which increases the electromagnetic driving force to >150N, significantly enhances the ability to overcome the inertia and friction of the pilot valve core 31, and reduces the mechanical friction coefficient by more than 50%, so that the step response time of the proportional flow servo valve 100 provided by this disclosure can be reduced from 30 ms to ≤16 ms.

[0058] In one embodiment of this disclosure, such as Figure 4 As shown, the proportional flow servo valve 100 also includes a detection unit 400. This detection unit 400 serves as the core feedback component of the closed-loop control hydraulic system of the proportional flow servo valve 100, acquiring real-time axial displacement information of the main valve core 20 to provide data support for precise flow control and to correspondingly regulate the action of the pilot valve 300. (Reference) Figure 3 The detection unit 400 includes a detection rod 401 that extends into the first control chamber 201 and engages with the main valve core 20. The detection unit 400 detects the displacement of the main valve core 20 through the detection rod 401. To ensure detection accuracy, both the detection unit 400 and the detection rod 401 are coaxially arranged with the main valve core 20. This coaxial arrangement ensures that the movement trajectory of the detection rod 401 and the main valve core 20 completely coincides, avoiding detection deviations caused by installation eccentricity, thereby improving the consistency and reliability of displacement detection. One end of the detection rod 401 engages with the end of the main valve core 20, including but not limited to a floating engagement structure. This allows for real-time response to the axial displacement of the main valve core 20 and effectively offsets minor coaxiality errors that may occur during assembly, avoiding additional resistance to the movement of the main valve core 20 and ensuring the smooth operation of the main valve core 20. The other end of the detection rod 401 extends into the detection chamber of the detection unit 400, forming a stable detection engagement relationship with the other detection elements.

[0059] For example, the detection unit 400 can detect the displacement of the main valve core 20 using a displacement sensor. The displacement sensor can be a grating ruler or an inductive sensor; the specific type can be flexibly selected according to the application scenario and control requirements of the servo valve, and is not limited here. Grating rulers or inductive sensors offer high detection accuracy and can provide real-time, precise feedback on the displacement information of the main valve core 20. Furthermore, the detection rod 401 can be made of bearing steel, which possesses excellent mechanical strength and hardness, meeting the structural stability requirements under long-term reciprocating motion scenarios. Its surface is chrome-plated, providing good wear resistance and corrosion resistance. In addition, the detection unit 400 can also incorporate a pressure sensor (accuracy ±0.5% FS) and a stroke position signal switch (resolution 0.01mm) to collect valve core displacement, inlet and outlet pressure data in real time. Based on a neural network-based fault identification model, by analyzing the deviation of the "flow-pressure" curve, it achieves real-time diagnosis of eight types of faults, including valve jamming and leakage (accuracy ≥99%). The data is transmitted to the control center via a CAN bus.

[0060] The detection unit 400 adopts a modular integrated design, integrating pressure, flow, and position sensors to monitor the valve group status in real time, thereby enabling online fault diagnosis without relying on offline detection. Its compact structure can fit within the overall installation space of the proportional flow servo valve 100 without increasing the servo valve's size, and facilitates assembly, disassembly, and maintenance, further improving the ease of use and economical operation of the servo valve.

[0061] In one embodiment of this disclosure, such as Figure 5 As shown, the proportional electromagnet 35 includes a control rod 351 connected to the pilot valve core 31. A manual unit 36 ​​is provided at the end of the proportional electromagnet away from the pilot valve core 31. The manual unit 36 ​​includes a base 362 with an inner cavity, a manual adjustment rod 361 located within the base 362, and a cover plate 363 sealing the inner cavity on the outer end face of the base 362. The manual adjustment rod 361 cooperates with the control rod 351 to drive the pilot valve core 31 to move. Specifically, the control rod 351 of the proportional electromagnet 35 is coaxially arranged with the pilot valve core 31 to ensure the stability of the proportional electromagnet 35 when pushing the pilot valve core 31. The cover plate 363 can be connected to the base 362 by threads or fixed to the base 362 by bolts; no limitation is made here. A sealing element is provided at the connection between the cover plate 363 and the base 362 to seal the inner cavity of the base 362 and ensure the sealing performance of the pilot valve 300.

[0062] In one specific embodiment of this disclosure, the manual adjustment rod 361 can be a threaded rod structure. The inner cavity of the base 362 is provided with a threaded hole that mates with the manual adjustment rod 361. The threaded hole is coaxially arranged with the control rod 351, and the coaxiality error is ≤0.1mm. One end of the manual adjustment rod 361 extends into the inner cavity of the base 362 through the threaded hole and mates with the control rod 351 of the proportional electromagnet 35. When manual operation is required, the cover plate 363 is removed, and the manual adjustment rod 361 is moved along the axial direction through threaded transmission, which pushes the control rod 351 to drive the pilot valve core 31 to move. The rotation angle of the manual adjustment rod 361 is linearly related to the displacement of the pilot valve core 31, thereby achieving precise adjustment of the opening degree.

[0063] In another specific embodiment of this disclosure, the manual adjustment lever 361 has a stepped shaft structure, with a ball joint at one end and a cylindrical handle at the other end, and the surface is provided with anti-slip texture. The inner cavity of the base 362 is provided with a guide sleeve, and the manual adjustment lever 361 slides with the base 362 through the guide sleeve, with a sliding clearance of 0.01-0.02 mm to ensure smooth movement. One end of the connecting rod is connected to the ball joint of the manual adjustment lever 361 through a pin, and the other end is connected to the middle of the control lever 351 through a pin, forming a crank-connecting rod mechanism. When manual operation is required, the cover plate 363 is removed, and the handle is held to push or pull the manual adjustment lever 361. The manual adjustment lever 361 slides along the guide sleeve and drives the control lever 351 to swing around its own axis through the connecting rod, thereby driving the pilot valve core 31 to move along the axis. The linear displacement of the manual adjustment lever 361 is linearly related to the displacement of the pilot valve core 31, realizing rapid reversal and flow regulation. The linkage drive requires little operating force, making it suitable for rapid operation in emergency situations. It can quickly switch the pilot valve core 31 to the safe neutral position or the required operating position. The ball joint and pin connection allow for a certain degree of movement deviation, avoiding jamming caused by installation errors and improving operational flexibility. The anti-slip texture on the handle surface increases grip friction, making it easier for the operator to apply force. The elastic sealing gasket ensures sealing performance, preventing oil leakage and impurities from entering. The design of the elongated hole provides sufficient space for the movement of the manual adjustment lever 361.

[0064] The above embodiments are not exhaustive, and this disclosure includes, but is not limited to, the connection methods specifically disclosed above.

[0065] In a specific embodiment of this disclosure, a "single electromagnet drive + servo-level valve core and sleeve" structure is adopted. The proportional electromagnet 35 coil uses 0.57 mm enameled wire with 1080 turns, increasing the electromagnetic driving force to 385N. All valve cores and sleeves are made of 40CrNiMoA alloy material, and the mating clearance is ensured to be 3-5μm through high-precision EDM (accuracy ±1μm), with the coverage controlled at 2-4μm. The drive method integrates a digital controller (built-in 32-bit DSP chip) and adopts a current closed-loop control algorithm, compressing the response time to 16ms (a 47% improvement over the traditional method).

[0066] In one specific embodiment of this disclosure, when the hydraulic system of the proportional flow servo valve 100 is powered off or the proportional solenoid 35 malfunctions, the operation of the pilot valve core 31 can be directly intervened through the manual unit 36. The operator can rotate or push the manual adjustment lever 361 to directly overcome spring force or hydraulic resistance through threaded or connecting rod transmission, forcing the pilot valve core 31 to switch direction or adjust its opening, thus achieving "manual overriding control." For example, the pilot valve core 31 can be manually switched to the safe neutral position to adjust the flow or pressure to meet emergency operating conditions, preventing the system from losing control due to power failure or malfunction.

[0067] The installation layout of placing the cover plate 363 on the outside of the base 362 to seal the inner cavity ensures the convenience and reliability of "manual overriding control": the manual unit 36 ​​is arranged at the end of the proportional electromagnet 35 away from the pilot valve core 31, so that it still has sufficient operating space after installation. The manual adjustment rod 361 can be operated by directly removing the cover plate 363 without disassembling pipelines or other components.

[0068] The proportional flow servo valve 100 disclosed herein embodies precise electro-hydraulic signal conversion throughout the entire regulation process, constituting a dynamic closed-loop control process. First, the detection unit 400 receives a command (e.g., ±10V) from an upper-level controller (such as a PLC). The detection unit 400 compares the command signal (set value) with the detected displacement signal of the main valve core 20. If a deviation exists, the detection unit 400 outputs a corresponding current signal to the proportional electromagnet 35 of the pilot valve 300. The proportional electromagnet 35 pushes the pilot valve core 31 to overcome the return spring force, generating precise displacement. The displacement of the pilot valve core 31 changes the opening size and direction of the pilot oil passage. For example, the movement of the pilot valve core 31 guides the pilot pressure to the first control chamber 201 of the main valve core 20, causing the main valve core 20 to move to the right, connecting the main oil passage. Oil flows out from the inlet 25 through the second outlet 26, driving the actuator. Simultaneously, the displacement of the main valve core 20 is detected in real time by the detection unit 400, continuously comparing the set value with the detected value until the main valve core 20 moves to the position required by the command. The entire adjustment process forms a closed-loop control of electrical command → pilot valve core displacement → pilot oil circuit switching → main valve core displacement → main oil circuit flow / direction change → position detection → electrical command correction. Through the design of the pilot stage and main valve stage, as well as electro-hydraulic closed-loop control, high-precision and high-reliability control of the hydraulic system power stage is achieved.

[0069] When a traditional large-diameter valve is opened, the massive flow instantly impacts the main valve core 20, generating a huge hydraulic force in the closing direction, hindering the rapid opening of the main valve core 20. However, the stepped throttling groove 21 opens in stages, with each stage generating a relatively smaller hydraulic force, effectively dispersing the hydraulic force. Therefore, the proportional electromagnet 35 can overcome the initial hydraulic force with less force and more quickly, accelerating the movement of the main valve core 20, thus shortening the "opening response time" from receiving the signal to the main valve core 20 reaching the predetermined opening degree. Similarly, when the oil circuit of the main valve core 20 needs to be closed, the stepped throttling groove 21 also allows for a smoother release of pressure throughout the hydraulic system, effectively avoiding pressure shocks while achieving rapid closure.

[0070] As previously mentioned, the proportional flow servo valve 100 of this disclosure has the ability to "step-by-step reduce pressure" which makes it particularly good at handling situations where the pressure difference between the inlet and outlet is very large. It can smoothly dissipate the high pressure difference on the multi-stage throttling groove 21, thereby avoiding excessive impact and pressure difference on individual parts of the system, and maintaining the overall structural integrity and functional stability under extreme pressure conditions.

[0071] In a specific embodiment of this disclosure, compared to the prior art, the proportional flow servo valve 100 provided by this disclosure can meet the requirements of a hydraulic servo control system through a stepped multi-stage throttling groove 21. In traditional hydraulic servo control systems, high-flow-rate, high-frequency-response proportional valves are a core requirement in high-end fields such as aerospace launches and heavy metallurgical equipment. The maximum flow rate in existing technologies (such as the Moog G66 series) is typically ≤ 600 L / min, and has the following drawbacks: (1) Flow bottleneck: The traditional main valve adopts a single throttling groove structure and the flow channel design is simple, which leads to flow saturation under high pressure differential and cannot break through the 1000L / min threshold.

[0072] (2) The contradiction between control accuracy and stability: Under high flow conditions, the hydraulic dynamics and cavitation phenomena are aggravated, resulting in obvious cavitation noise; the response time is 30-50 ms; the flow control accuracy is ±2% (high pressure difference), so it is difficult to balance response speed and accuracy.

[0073] (3) Insufficient structural reliability: The high impact force brought by the large flow rate can easily lead to valve core wear and sealing failure, with a mean time between failures (MTBF) of only about 10,000 hours.

[0074] This disclosure overcomes the above-mentioned difficulties by using the throttling groove 21 set on the shoulder 22 of the main valve core 20 and the overall structure of the proportional flow servo valve 100, achieving stable and precise control of a large flow rate of 1000L / min with a response time ≤16ms. CFD verification shows that it can achieve a cavitation-free effect and a mean time between failures (MTBF) of ≥20,000 hours.

[0075] The main valve core 20 and the proportional flow servo valve 100 provided in this disclosure are manufactured using electrical discharge machining and employ a 0.001mm level form and position tolerance control method.

[0076] Based on the cavitation resistance, vibration resistance, and high pressure differential resistance characteristics of the main valve core 20 and the proportional flow servo valve 100 provided in this disclosure, the products of this disclosure can be applied in fields with harsh working environments and drastic load changes, such as metallurgy, mining, and engineering machinery.

[0077] In one specific embodiment of this disclosure, it is assumed that the flow rate formula satisfied by the throttling groove 21 in this embodiment is:

[0078] in, Q Flow rate refers to the volume of fluid passing through the throttling groove 21 per unit time, commonly expressed in cubic meters (m³). 3 / s, L / min, etc.; C dThe flow coefficient (or outflow coefficient) is a dimensionless constant that reflects the influence of the geometry of the throttling channel 21, flow field effects, etc. on the flow rate. A ( x ): The flow area of ​​the throttling groove 21 is equal to the displacement of the main valve core 20. x The function (which varies with the movement of the valve core), with units of m. 2 (e.g. mm) 2 ); Δ P The pressure difference before and after the throttling groove 21 is the pressure difference between the inlet and outlet of the throttling groove 21 of the main valve core 20, in Pa (or bar). ρ The density of the fluid refers to the density of the hydraulic oil (or other fluid) flowing through the throttling groove 21, and the unit is kg / m³. 3 .

[0079] Flow rate of throttling groove 21 Q Displacement of the main valve core 20 x Under the ideal target, there is a strictly linear relationship, that is... Q = K · x ,in K Let be a constant, representing the flow gain (e.g., the flow rate increases by 1 L / min for every 1 mm of movement). Establish the equation and solve it inversely. A ( x Substitute the ideal target into the flow formula:

[0080] Then the solution can be found A ( x )for:

[0081] The ideal flow area curve required to achieve target linear flow control A ideal ( x )satisfy:

[0082] Let the constant term be M ,Right now:

[0083] The ideal formula then simplifies to:

[0084] When using the ideal formula as a benchmark to guide the design and compensation algorithm of the stepped throttling groove 21 disclosed herein, it is assumed that the main valve core 20 moves to the bottom (end) of the first throttling groove 211, i.e., at step 213, and the displacement...x = x 1. The area contributed by the first throttling channel 211 is:

[0085] At this displacement, the ideal total area is A ideal ( x ), then in x One point is that the "insufficiency" or "deviation" in the circulation area is:

[0086] Continuing to assume that when the main valve core 20 is from x 1. Continue moving to x At 2 o'clock, the second throttling channel 212 begins to work, during this stroke ( x 2 - x 1) Inside, the total flow area of ​​the stepped throttling channel 21 is:

[0087] The above formulas satisfy x 1 < x ≤ x 2; Therefore, if we want A total ( x As close as possible A ideal ( x If the second throttling channel 212 needs to compensate for the flow from... x 1 to x A deviation of 2, that is, at any point x The second throttling channel 212 needs to meet the following requirements:

[0088] Because, if A 2( x If the initial growth is too slow, then A total ( x It will be lower than A ideal ( x This leads to a slow increase in hydraulic oil flow, resulting in a "flow plateau"; if A 2( x If the initial growth is too fast, then A total ( x It will exceed A ideal ( xThis can cause a sudden jump in flow rate through the throttling groove 21. To avoid these phenomena, the shape of the throttling groove 21 in this embodiment (including but not limited to triangular, arc-shaped, or trapezoidal shapes) should satisfy the requirement that the main valve core 20... x 1 Move to x At time 2, the change in flow area caused by the opening of the stepped multi-stage throttling channel 21 A 2( x We will try to fit this ideal compensation curve as closely as possible.

[0089] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein. The scope of this disclosure is defined by the appended claims.

Claims

1. A main valve core (20), characterized in that, The valve core body extends along the X-axis and has a stepped throttling groove (21) on it. The throttling groove (21) is configured to include at least a first throttling groove (211) and a second throttling groove (212). The first throttling groove (211) and the second throttling groove (212) are interconnected and are configured to be distributed in the X-axis direction. A step (213) is formed at the position where the first throttling groove (211) and the second throttling groove (212) are connected. The size of the first throttling groove (211) and the second throttling groove (212) is configured to increase sequentially.

2. The main valve core (20) according to claim 1, characterized in that, The radial depth of the second throttling groove (212) on the valve core body is greater than the radial depth of the first throttling groove (211), and the difference in radial depth between the first throttling groove (211) and the second throttling groove (212) constitutes the height of the step (213).

3. The main valve core (20) according to claim 1, characterized in that, Multiple throttling grooves (21) are provided at intervals in the circumferential direction of the valve core body.

4. The main valve core (20) according to claim 1, characterized in that, The valve core body is provided with annular shoulders (22) spaced apart along the X-axis direction, and the throttling grooves (21) are respectively provided on opposite sides of the shoulders (22) in the axial direction.

5. The main valve core (20) according to claim 1, characterized in that, The shape of the throttling groove (21) is constructed as a triangle, an arc or a trapezoid.

6. A proportional flow servo valve (100), characterized in that, Includes a main valve body (200), said main valve body (200) comprising: The main valve seat (23) is configured to have a main valve chamber (24), and the main valve seat (23) is provided with an oil inlet (25) and an oil outlet (26) communicating with the main valve chamber (24). According to any one of claims 1 to 5, the main valve core (20) is movably connected in the main valve chamber (24) and is configured to allow the first throttling groove (211) and the second throttling groove (212) to communicate with the oil outlet (26) in sequence during movement.

7. The proportional flow servo valve (100) according to claim 6, characterized in that, The oil outlet (26) includes a first working oil port (261) and a second working oil port (262). The main valve core (20) is configured to move along the X-axis to selectively connect the oil inlet (25) to the first working oil port (261) or the oil inlet (25) to the second working oil port (262) through the corresponding throttling groove (21).

8. The proportional flow servo valve (100) according to claim 6, characterized in that, The positions of the main valve chamber (24) located at opposite ends of the main valve core (20) are respectively referred to as the first control chamber (201) and the second control chamber (202); The proportional flow servo valve (100) includes a pilot valve (300), which includes a pilot valve seat (30) and a pilot valve core (31). The pilot valve seat (30) is configured to have a pilot valve (300) cavity that cooperates with the pilot valve core (31), and a first pilot oil outlet (33), a second pilot oil outlet (34), and a pilot oil inlet that communicate with the pilot valve (300) cavity. The first pilot oil outlet (33) is configured to communicate with a first control cavity (201), and the second pilot oil outlet (34) is configured to communicate with a second control cavity (202). The proportional flow servo valve (100) includes a proportional electromagnet (35), and the pilot valve core (31) is configured to be controlled by the proportional electromagnet (35) to move to a passage connecting the pilot oil inlet to the first pilot oil outlet (33), or the pilot oil inlet to the second pilot oil outlet (34).

9. The proportional flow servo valve (100) according to claim 8, characterized in that, The proportional flow servo valve (100) includes a detection unit (400) configured to include a detection rod (401) extending into the first control chamber (201) and cooperating with the main valve core (20), the detection unit (400) being configured to detect the displacement of the main valve core (20) via the detection rod (401).

10. The proportional flow servo valve (100) according to claim 8, characterized in that, The proportional electromagnet (35) includes a control rod (351) connected to the pilot valve core (31); a manual unit (36) is provided at one end of the proportional electromagnet away from the pilot valve core (31), the manual unit (36) includes a base (362) with an inner cavity and a manual adjustment rod (361) located in the base (362), and a cover plate (363) sealing the inner cavity is provided on the outer end face of the base (362); the manual adjustment rod (361) is configured to cooperate with the control rod (351) to drive the pilot valve core (31) to move through the control rod (351).

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