A pilot proportional pressure reducing valve

Abstract

The present disclosure relates to a pilot proportional pressure reducing valve, comprising a main valve unit and an upper pilot control unit; the main valve unit comprises a main valve body and a movable main valve core in the main valve cavity of the main valve body, and the two ends of the main valve cavity are respectively provided with a first chamber and a second chamber; the main valve body is provided with an oil inlet, an oil outlet and an oil drain, and corresponding oil inlet channel, oil outlet channel and oil drain channel; the first channel and the second channel are arranged on the main valve core, and the main valve core moves to connect the oil inlet channel, the main valve cavity and the oil outlet channel by the pressure difference of the two chambers; the pilot control unit comprises a pilot valve body, a proportional solenoid, a pilot valve seat and a through oil passage; the pilot valve cavity is divided into a third chamber connected with the first chamber and a fourth chamber connected with the oil drain channel; the proportional solenoid adjusts the sealing of the oil passage of the valve rod; when the oil pressure of the first chamber and the third chamber is greater than the first threshold value, the valve rod opens the oil passage to drain oil. The present disclosure accurately controls the valve rod through the proportional solenoid, and realizes the rapid and accurate stable adjustment of the oil pressure by matching the pressure difference driving of the main valve core.

Description

Technical Field

[0001] This disclosure relates to the field of hydraulic technology, specifically to a pilot-operated proportional pressure reducing valve. Background Technology

[0002] In existing technologies, pilot-operated pressure reducing valves, as core pressure regulating elements in fluid control systems, are widely used in various hydraulic and pneumatic systems. They achieve pressure control through the cooperation of the pilot valve and the main valve. The pressure regulating function of conventional pilot valves relies on mechanical pressure regulating springs, which has obvious technical limitations: relying on the mechanical characteristics of the pressure regulating springs makes it difficult to achieve continuous and precise proportional pressure output through electrical signals, failing to meet the dynamic pressure regulation requirements of modern automation systems; furthermore, the integration of pilot valve components with the valve body is low, the assembly process is cumbersome, and subsequent replacement and maintenance require disassembly of multiple related components, which is time-consuming and labor-intensive; at the same time, the core components inside the main valve, such as the valve core and valve sleeve, are mostly customized integrated structures, with a narrow range of adaptability. Different operating conditions require replacement of the entire valve or a large number of parts, resulting in high operating costs. These problems constitute technical pain points that urgently need to be solved in practical applications. Utility Model Content

[0003] This disclosure provides a pilot-operated proportional pressure reducing valve to address the problems existing in the prior art.

[0004] According to the present disclosure, a pilot-operated proportional pressure reducing valve includes a main valve unit and a pilot control unit disposed above the main valve unit; The main valve unit includes a main valve body and a main valve core. The main valve body is configured to have a main valve cavity, and the main valve core is configured to be movably connected within the main valve cavity. One end of the main valve cavity is configured to form a first chamber, and the other end forms a second chamber. The main valve body is provided with an oil inlet, an oil outlet, and an oil drain port; the main valve body is also provided with an oil inlet channel communicating with the oil inlet, an oil outlet channel communicating with the oil outlet, and an oil drain channel communicating with the oil drain port; the main valve core is provided with a first channel communicating the oil inlet channel to the first chamber, and a second channel communicating the oil outlet channel to the second chamber; the main valve core is configured to move to the passage connecting the oil inlet channel, the main valve chamber, and the oil outlet channel under the pressure difference between the first chamber and the second chamber; The pilot control unit includes a pilot valve body and a valve stem controlled by a proportional electromagnet. The pilot valve body includes a pilot valve chamber with a first outlet and a pilot valve seat located within the pilot valve chamber. The pilot valve seat has a through oil passage. The pilot valve chamber has a third chamber communicating with the first chamber and a fourth chamber communicating with a drain passage at both ends of the oil passage. The proportional electromagnet is configured to seal the oil passage located in the fourth chamber under the action of an adjusting force. When the oil pressure in the first chamber and the third chamber is greater than the first threshold, the valve stem is pushed to open the oil passage so that the oil in the first chamber flows out through the third chamber, the oil passage, the fourth chamber, and the drain passage.

[0005] In one embodiment of this disclosure, a protective valve is provided in the third chamber, and the protective valve is provided with a second outlet communicating with the oil drain channel; the protective valve is configured to open the second outlet when the pressure in the third chamber is greater than a second threshold; the second threshold is greater than the first threshold.

[0006] In one embodiment of this disclosure, the main valve core is provided with an oil passage groove, and the main valve core is configured to move to the passage connecting the oil inlet channel, the oil passage groove and the oil outlet channel under the pressure difference between the first chamber and the second chamber.

[0007] In one embodiment of this disclosure, a first spring is also included, which is located in the first chamber; when the pressure at the oil inlet is less than the set pressure of the first spring, the first spring holds the main valve core in the initial position to cut off the oil passage between the oil inlet and the oil outlet; the main valve core is configured to move to the passage connecting the oil inlet channel, the oil groove and the oil outlet channel under the pressure difference of the first chamber, the first spring and the second chamber.

[0008] In one embodiment of this disclosure, the main valve core is provided with a damping channel communicating with the second channel; the oil in the oil outlet channel is configured to flow into the second chamber through the oil groove, the damping channel, and the second channel; when the pressure in the second chamber is greater than the force of the first chamber and the first spring, the main valve core is pushed to move in the direction of the first chamber, so that the oil groove communicates with the oil drain channel.

[0009] In one embodiment of this disclosure, a control valve is provided in the first chamber. The control valve includes a control valve seat and a control valve core located in the inner cavity of the control valve seat. The control valve core is configured to be pre-pressed in the inner cavity of the control valve seat by a second spring. The first channel is configured to communicate with the first chamber sequentially through the control valve core and a communication port provided on the control valve seat. The oil pressure in the control valve seat is configured to push the control valve core to reduce the opening degree of the communication port when it is greater than a third threshold.

[0010] In one embodiment of this disclosure, the main valve chamber is configured to form a mounting port through one side of the main valve body; the main valve core, control valve seat, and control valve core are configured to extend into the main valve chamber through the mounting port.

[0011] In one embodiment of this disclosure, a screw plug is provided at the mounting port, the screw plug being configured to seal the main valve core, control valve seat, and control valve core within the main valve cavity.

[0012] In one embodiment of this disclosure, the main valve unit further includes a one-way valve, which is configured to be located in a one-way valve chamber provided on the main valve body; the inlet of the one-way valve chamber is configured to communicate with the oil outlet channel via the oil passage groove; the outlet of the one-way valve chamber is configured to communicate with the oil inlet channel via the oil return groove provided on the main valve core; the one-way valve is configured to allow only the passage from the inlet to the outlet to be opened.

[0013] In one embodiment of this disclosure, the end of the valve stem used to seal or open the oil passage is configured to be tapered.

[0014] One beneficial effect of this disclosure is that the pilot-operated proportional pressure reducing valve of this disclosure includes a main valve unit and a pilot control unit above it; the main valve unit includes a main valve body and a main valve core, the main valve core is movably connected in the main valve cavity of the main valve body, and the two ends of the main valve cavity form a first chamber and a second chamber respectively; the main valve body is provided with an oil inlet, an oil outlet and a drain port, as well as correspondingly connected oil inlet channels, oil outlet channels and drain channels; the main valve core is provided with a first channel connecting the oil inlet channel to the first chamber and a second channel connecting the oil outlet channel to the second chamber; the main valve core moves to the passage connecting the oil inlet channel, the main valve cavity and the oil outlet channel under the action of the pressure difference between the first chamber and the second chamber. The pilot control unit includes a pilot valve body, a proportional electromagnet, a pilot valve seat, and an oil passage penetrating the pilot valve seat. The pilot valve seat is located within the pilot valve chamber, which is divided into a third chamber connecting to the first chamber and a fourth chamber connecting to the drain passage at both ends of the oil passage. The proportional electromagnet adjusts its valve stem to seal the oil passage. When the oil pressure in the first and third chambers exceeds a first threshold, the oil pressure pushes the valve stem to open the oil passage, allowing the oil in the first chamber to flow out through the third chamber, the oil passage, the fourth chamber, and the drain passage. This disclosure achieves rapid and stable oil pressure regulation through precise valve stem control by a proportional electromagnet, combined with differential pressure drive of the main valve core. It boasts high pressure control accuracy and is suitable for efficient operation of hydraulic systems.

[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 schematic diagram of the structure of the pilot-operated proportional pressure reducing valve provided in the embodiments of this disclosure; Figure 2 This is a schematic diagram of the main valve unit in an embodiment of this disclosure; Figure 3 This is a schematic diagram of the pilot control unit in an embodiment of this disclosure; Figure 4 yes Figure 1 A magnified view of a portion of point A in the middle; Figure 5 yes Figure 1 A magnified view of a portion of point B in the middle; Figure 6 yes Figure 1 A magnified view of a portion of point C.

[0018] Figures 1 to 6 The one-to-one correspondence between the component names and the reference numerals in the figures is as follows: 100. Main valve unit; 111. Main valve body; 112. Main valve core; 113. Main valve chamber; 120. Oil inlet; 121. Oil inlet passage; 130. Oil outlet; 131. Oil outlet passage; 140. Oil drain port; 141. Oil drain passage; 150. Mounting port; 151. Control valve seat; 152. Control valve core; 153. Connecting port; 154. First spring; 155. Second spring; 156. Plug; 160. Check valve; 161. Check valve chamber; 162. Check valve seat; 163. Check valve core; 164. Second inlet; 165. Third outlet; 101. First chamber; 102. Second chamber; 103. First channel; 104. Second channel; 105. Damping channel; 106. Oil trough; 107. Oil return trough; 108. First branch; 200. Pilot control unit; 211. Pilot valve body; 212. Pilot valve chamber; 213. Pilot valve seat; 214. Oil passage; 220. Proportional electromagnet; 221. Valve stem; 201. Third chamber; 202. Fourth chamber; 203. First inlet; 204. First outlet; 205. Second outlet; 206. First drain; 207. Second drain; 208. Second branch; 230. Protective valve. 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 pilot-operated proportional pressure reducing valve, including a main valve unit and a pilot control unit above it; the main valve unit includes a main valve body and a main valve core, the main valve core being movably connected in the main valve cavity of the main valve body, the two ends of the main valve cavity forming a first chamber and a second chamber respectively; the main valve body is provided with an oil inlet, an oil outlet and a drain port, as well as correspondingly connected oil inlet channels, oil outlet channels and drain channels; the main valve core has a first channel connecting the oil inlet channel to the first chamber and a second channel connecting the oil outlet channel to the second chamber; the main valve core moves to the passage connecting the oil inlet channel, the main valve cavity and the oil outlet channel under the pressure difference between the first chamber and the second chamber. The pilot control unit includes a pilot valve body, a proportional electromagnet, a pilot valve seat, and an oil passage through the pilot valve seat. The pilot valve seat is located in the pilot valve chamber, which is located at both ends of the oil passage and has a third chamber connecting to the first chamber and a fourth chamber connecting to the drain passage. The proportional electromagnet adjusts its valve stem to seal the oil passage. When the oil pressure in the first chamber and the third chamber is greater than a first threshold, the oil pressure pushes the valve stem to open the oil passage so that the oil in the first chamber flows out through the third chamber, the oil passage, the fourth chamber, and the drain passage.

[0027] The pilot-operated proportional pressure reducing valve provided by this invention replaces the traditional pressure regulating spring with a proportional electromagnet. It can be used with an electronic amplifier to receive continuously changing electrical signals. After processing by the proportional amplifier, the valve stem of the pilot valve is controlled by an electromagnetic force proportional to the electrical signal, thereby achieving continuous and precise pressure regulation. Combined with the differential pressure drive of the main valve core, it achieves rapid and stable oil pressure regulation, high pressure control accuracy, and is suitable for efficient operation of hydraulic systems.

[0028] The specific embodiments of this disclosure are described below with reference to the accompanying drawings.

[0029] refer to Figure 1 This disclosure provides a pilot-operated proportional pressure reducing valve, including a main valve unit 100 and a pilot control unit 200 disposed above the main valve unit 100. The pilot-operated proportional pressure reducing valve precisely controls pressure according to the input electrical signal, converting the electrical signal into a corresponding pressure output and maintaining pressure stability. It is suitable for hydraulic applications requiring adjustable pressure and high pressure control accuracy. The main valve unit 100 is the main actuator for the pressure reducing function. The pilot control unit 200 receives the proportional electrical signal, converts it into a corresponding hydraulic control pressure, and applies it to the main valve unit 100, driving the main valve unit 100 to complete the pressure reduction adjustment. Simultaneously, the pilot control unit 200 can sense pressure changes and fine-tune the control pressure through a feedback mechanism, correcting the opening degree of the main valve unit 100, thereby improving pressure control accuracy.

[0030] refer to Figure 2 The main valve unit 100 includes a main valve body 111 and a main valve core 112. The main valve body 111 has a main valve cavity 113, and the main valve core 112 is movably connected within the main valve cavity 113. One end of the main valve cavity 113 forms a first chamber 101, and the other end forms a second chamber 102. The main valve body 111 provides mounting support for each component and bears the medium pressure. The main valve core 112 can be a columnar moving component. The main valve core 112 is precisely matched with the main valve cavity 113 and can adopt a sliding or axially moving structure, moving flexibly along the axis of the main valve cavity 113. The main valve core 112 changes its relative position with the main valve body 111 through axial displacement, thereby switching the flow path, adjusting the opening, and realizing medium on / off and flow control. Furthermore, a main valve sleeve can be installed inside the main valve chamber 113, with the main valve core 112 movably installed within the main valve sleeve and precisely fitted to its dimensions. The main valve sleeve has corresponding openings in the main valve core 112 to ensure the switching of the oil circuit controlled by the main valve core 112. The main valve sleeve adapts to the stepped structure inside the main valve chamber 113, achieving precise positioning and installation with the main valve chamber 113. Simultaneously, a sealing groove can be machined on the outer wall of the main valve sleeve to enhance the sealing performance of the main valve chamber 113 by adding sealing elements, preventing media leakage between chambers from affecting pressure reduction accuracy. The first chamber 101 and the second chamber 102 are symmetrically distributed at both ends of the main valve core 112, and both are sealed chambers. The first chamber 101 can communicate with the pilot control unit 200, receiving pressure transmitted by the pilot control unit 200 to provide partial driving force for the movement of the main valve core 112; the second chamber 102 is connected to the oil outlet channel 131 through the main valve core 112, forming pressure feedback or pressure balancing.

[0031] The main valve body 111 is provided with an oil inlet 120, an oil outlet 130, and an oil drain port 140. The main valve body 111 also has an oil inlet channel 121 communicating with the oil inlet 120, an oil outlet channel 131 communicating with the oil outlet 130, and an oil drain channel 141 communicating with the oil drain port 140. Specifically, the oil inlet 120, oil outlet 130, and oil drain port 140 can all adopt standardized thread or flange designs to facilitate precise connection with the oil circuits of other actuators or the oil tank circuits—the oil inlet 120 is used to connect hydraulic oil; the oil outlet 130 is responsible for outputting stable pressure oil after pressure reduction to the load element (such as a hydraulic cylinder, hydraulic motor, etc.); the oil drain port 140 is specifically for draining leaked oil, excess oil, and oil return oil from the main valve chamber 113, preventing oil stagnation that could cause pressure fluctuations or component overheating. The oil inlet channel 121, oil outlet channel 131, and oil drain channel 141 all feature optimized oil flow path layouts, with their diameters matching the rated flow requirements to reduce pressure loss along the flow path. The end of the oil inlet channel 121 is connected to the main valve chamber 113, the oil outlet channel 131 corresponds to the corresponding area on the main valve core 112, and the oil drain channel 141 ensures that the oil can be discharged quickly.

[0032] Combination Figure 4 The main valve core 112 is provided with a first channel 103 connecting the oil inlet channel 121 to the first chamber 101, and a second channel 104 connecting the oil outlet channel 131 to the second chamber 102. Under the pressure difference between the first chamber 101 and the second chamber 102, the main valve core 112 moves to the passage connecting the oil inlet channel 121, the main valve chamber 113, and the oil outlet channel 131. The first channel 103 and the second channel 104 are both opened along the axial direction of the main valve core 112, and the orifice diameter is adapted to the flow requirements of the corresponding channel. The inner wall of the channel is polished to reduce the oil flow resistance. When the main valve core 112 moves, a notch that can adjust the opening degree can be formed between its outer peripheral surface and the inner wall of the main valve chamber 113. By changing the opening degree of the notch, the flow area from the oil inlet channel 121 to the oil outlet channel 131 is adjusted, thereby realizing oil pressure reduction. The opening degree of the notch can be linearly correlated with the pressure difference between the two chambers.

[0033] In one specific embodiment of this disclosure, the main valve core 112 is provided with an oil passage groove 106. Under the pressure difference between the first chamber 101 and the second chamber 102, the main valve core 112 moves to the passage connecting the oil inlet channel 121, the oil passage groove 106, and the oil outlet channel 131. Figure 4As shown, the oil passage 106 is an annular groove formed on the outer circumference of the main valve core 112. It can be arranged along the axial direction of the main valve core 112, and the number can be adjusted according to specific working conditions. The width and depth of the oil passage 106 need to match the rated flow requirements, and the groove wall is rounded to reduce oil flow resistance. The position of the oil passage 106 needs to correspond to the position of the oil inlet channel 121 and the oil outlet channel 131 of the main valve body 111. When the main valve core 112 moves along the axis of the main valve cavity 113 under the action of pressure difference, the oil passage 106 will simultaneously cover the ports of the oil inlet channel 121 and the oil outlet channel 131, forming an oil passage from the oil inlet channel 121 through the oil passage 106 to the oil outlet channel 131. The oil groove 106 works in conjunction with the main valve core 112 and the main valve chamber 113 to reduce pressure when the oil flows through the oil groove 106. At the same time, the oil groove 106 can balance the radial pressure of the oil on the main valve core 112, avoiding jamming caused by uneven load.

[0034] like Figure 3 and Figure 6 As shown, the pilot control unit 200 includes a pilot valve body 211 and a valve stem 221 controlled by a proportional electromagnet 220. The pilot valve body 211 includes a pilot valve cavity 212 with a first outlet 204 and a pilot valve seat 213 located within the pilot valve cavity 212. The pilot valve seat 213 has a through oil passage 214. At both ends of the oil passage 214, the pilot valve cavity 212 forms a third chamber 201 communicating with the first chamber 101 and a fourth chamber 202 communicating with the drain passage 141, respectively. The pilot valve seat 213 is fixed in the pilot valve cavity 212 by an interference fit. The axis of the oil passage 214 is collinear with the axis of the pilot valve cavity 212 to ensure the centering accuracy when the valve stem 221 moves. The third chamber 201 is connected to the first branch 108 built into the main valve body 111 via the second branch 208 built into the pilot valve body 211, and is thus sealed to the first chamber 101. The fourth chamber 202 is connected to the oil drain channel 141. Both the third chamber 201 and the fourth chamber 202 are equipped with seals to prevent oil leakage from affecting control accuracy. One end of the pilot valve chamber 212 is a fixed end for mounting the proportional electromagnet 220, realizing the integrated assembly of the pilot valve and the proportional electromagnet 220.

[0035] The proportional electromagnet 220 is configured to seal the oil passage 214 located in the fourth chamber 202 under the action of an adjusting force. The output thrust of the proportional electromagnet 220 is proportional to the amplitude of the input electrical signal. It is rigidly connected to the end of the valve stem 221 away from the oil passage 214. The magnitude of the output thrust is adjusted by the electrical signal, thereby controlling the sealing pressure of the valve stem 221 on the oil passage 214. Upon receiving the adjustment signal, the proportional electromagnet 220 applies a preset thrust to tightly fit the end of the valve stem 221 against the port of the oil passage 214, achieving a sealed stop of the oil passage 214.

[0036] In one embodiment of this disclosure, the end of the valve stem 221 used to seal or open the oil passage 214 is tapered. Specifically, the tapered end of the valve stem 221 forms a cone valve, which can precisely match the mating surface of the oil passage 214 port to form a line seal structure to improve sealing reliability. At the same time, the cone valve also has a guiding function, reducing the risk of jamming when the valve stem 221 moves, and making the opening of the oil passage 214 change linearly with the displacement of the valve stem 221, which facilitates precise control of the oil leakage. This disclosure designs the proportional electromagnet 220 as a threaded cartridge type, integrating the cone valve, pilot valve seat 213 and proportional electromagnet 220, which can be directly screwed into the pilot valve body 211, greatly simplifying the installation and replacement process.

[0037] In one specific embodiment of this disclosure, the pilot-operated proportional pressure reducing valve uses an external amplifier. The proportional electromagnet 220 is available in two types: 0-1.6A and 0-0.8A. Due to limitations in wiring and installation space, users can also provide plug-in amplifiers, available in standard type 0-10V (A1) and model 4-20mA (F1). The plug-in amplifier has a DIN plug type, an IP65 waterproof rating, and can be set to match the pressure characteristics of the pilot-operated proportional pressure reducing valve of this disclosure. It allows setting the maximum and minimum current, chatter frequency, and linear compensation within the pressure range to adjust the pressure of the pilot-operated proportional pressure reducing valve.

[0038] When the oil pressure in the first chamber 101 and the third chamber 201 exceeds a first threshold, the valve stem 221 is pushed to open the oil passage 214, allowing the oil in the first chamber 101 to flow out through the third chamber 201, the oil passage 214, the fourth chamber 202, and the drain passage 141. Specifically, the first threshold is the equivalent pressure value corresponding to the sealing force applied to the valve stem 221 by the proportional electromagnet 220. When the thrust generated by the superposition of the oil pressures in the first chamber 101 and the third chamber 201 exceeds this threshold, the valve stem 221 overcomes the thrust of the proportional electromagnet 220 and moves away from the oil passage 214. After the oil passage 214 is opened, the high-pressure oil in the first chamber 101 flows sequentially through the third chamber 201, the oil passage 214, and the fourth chamber 202 into the drain passage 141, and finally is discharged from the drain port 140, thereby reducing the pressure in the first chamber 101. As the pressure in the first chamber 101 decreases, the pressure difference across the main valve core 112 gradually adjusts, causing the main valve core 112 to move in the opposite direction to reduce the opening until the pressure returns to the set value, thus achieving closed-loop feedback regulation of the pressure.

[0039] In one embodiment of this disclosure, reference is made to Figure 3A protection valve 230 is installed in the third chamber 201, and the protection valve 230 has a second outlet 205 communicating with the oil drain passage 141. The protection valve 230 is configured to open the second outlet 205 when the pressure in the third chamber 201 is greater than a second threshold; the second threshold is greater than the first threshold. Specifically, the protection valve 230 can adopt a direct-acting relief valve structure and is fixedly fitted to the inner wall of the third chamber 201. The core function of the protection valve 230 is overload protection. When the control pressure in the third chamber 201 exceeds the second threshold due to abnormal operating conditions, the oil pressure pushes the valve core of the protection valve 230 to move, so that the second outlet 205 is connected to the third chamber 201. The oil flows into the drain channel 141 through the second outlet 205 and the second drain channel 207, quickly discharging excess oil to reduce the pressure in the third chamber 201 and prevent excessive pressure from damaging precision components such as the pilot valve seat 213 and valve stem 221. The second threshold is ensured by the protection valve 230 to always be higher than the first threshold, so as not to affect the normal pressure reduction and regulation process.

[0040] like Figure 2 and Figure 5 As shown, in one embodiment of this disclosure, the pilot-operated proportional pressure reducing valve further includes a first spring 154 located in the first chamber 101. When the pressure at the oil inlet 120 is less than the set pressure of the first spring 154, the first spring 154 holds the main valve core 112 in its initial position to cut off the oil passage between the oil inlet 120 and the oil outlet 130. Under the pressure difference of the first chamber 101, the first spring 154, and the second chamber 102, the main valve core 112 moves to the passage connecting the oil inlet channel 121, the oil groove 106, and the oil outlet channel 131. Specifically, the first spring 154 can be a cylindrical helical compression spring. The first spring 154 can be sleeved on the end of the main valve core 112 near the first chamber 101, with one end abutting the end face of the main valve core 112 and the other end abutting the end face of the control valve seat 151, and has a preset preload after assembly. When the pressure at the oil inlet is less than the set pressure of the first spring 154, the first spring 154 pushes the main valve core 112 to move along the axis of the main valve chamber 113 toward the second chamber 102 to the initial position. At this time, the oil groove 106 of the main valve core 112 is completely misaligned with the oil inlet channel 121 and the oil outlet channel 131, cutting off the oil passage between the oil inlet 120 and the oil outlet 130. When the pilot-operated proportional pressure reducing valve is working, the hydraulic pressure of the first chamber 101 and the preload of the first spring 154 are superimposed to form an axial force, which forms a pressure difference with the feedback pressure of the second chamber 102. Under the action of this pressure difference, the main valve core 112 moves flexibly, thereby adjusting the overlap between the oil groove 106 and the oil inlet channel 121 and the oil outlet channel 131, so as to achieve precise pressure adjustment of the opening.

[0041] In one specific embodiment of this disclosure, reference is made to Figure 1When the pilot-operated proportional pressure reducing valve is stationary, the oil inlet 120 is in a pressureless state. At this time, the first spring 154 keeps the main valve core 112 in the initial position, and the oil passage between the oil inlet 120 and the oil outlet 130 is cut off. This can avoid sudden changes caused by a sudden increase in pressure when the pilot-operated proportional valve is started.

[0042] In one specific embodiment of this disclosure, reference is made to Figures 1 to 6 When the pilot-operated proportional pressure reducing valve is in operation, if the pressure at the oil outlet 130 is lower than the set value, the main valve core 112 is pushed towards the direction of the second chamber 102 under the pressure difference of the first chamber 101, the first spring 154, and the second chamber 102. The main valve core 112 moves to the passage connecting the oil inlet channel 121, the oil groove 106, and the oil outlet channel 131, that is, to connect the passage from the oil inlet 120 to the oil outlet 130. When the oil outlet 130 reaches the required pressure, the main valve core 112 is balanced by force and remains in the working position to maintain the passage.

[0043] In one embodiment of this disclosure, the main valve core 112 is provided with a damping channel 105 communicating with the second channel 104; the oil in the oil outlet channel 131 is configured to flow into the second chamber 102 via the oil groove 106, the damping channel 105, and the second channel 104. When the pressure in the second chamber 102 is greater than the force of the first chamber 101 and the first spring 154, it pushes the main valve core 112 to move in the direction of the first chamber 101, so that the oil groove 106 communicates with the oil drain channel 141. Figure 4 As shown, the damping channel 105 is a fine-hole channel radially opened along the main valve core 112. The diameter of the damping channel 105 is smaller than that of the second channel 104. One end of the damping channel 105 is connected to the oil groove 106 on the outer circumference of the main valve core 112, and the other end is perpendicularly connected to the second channel 104. When oil return is required, the oil returning from the oil outlet 130 first enters the oil outlet channel 131 under pressure. The oil in the oil outlet channel 131 first flows into the oil groove 106, and part of the oil enters the second channel 104 after being throttled by the damping channel 105, and finally flows smoothly into the second chamber 102. The throttling effect of the damping channel 105 can slow down the pressure change rate of the second chamber 102, avoid the main valve core 112 from high-frequency oscillation due to pressure fluctuations, and improve the pressure control stability. When the feedback pressure in the second chamber 102 continues to rise and exceeds the combined force of the pressure in the first chamber 101 and the preload of the first spring 154, the main valve core 112 will move axially toward the first chamber 101, causing the oil groove 106 on the outer circumference of the main valve core 112 to coincide with the port of the oil drain channel 141 of the main valve body 111, and the excess oil will be discharged through the oil drain channel 141, thus achieving pressure relief.

[0044] In one embodiment of this disclosure, a control valve is disposed within a first chamber 101. The control valve includes a control valve seat 151 and a control valve core 152 located within the inner cavity of the control valve seat 151. The control valve core 152 is pre-pressed against the inner cavity of the control valve seat 151 by a second spring 155. Figure 2 and Figure 5 As shown, the control valve seat 151 can be a cylindrical structure, with an interference fit to the end of the main valve chamber 113 near the first chamber 101. The control valve core 152 and the second spring 155 are installed inside. The control valve core 152 can also be a columnar structure, precisely sliding with the inside of the control valve seat 151. The second spring 155 can be a cylindrical helical compression spring, sleeved on the tail of the control valve core 152, with one end abutting the end face of the control valve core 152 and the other end abutting the bottom of the control valve seat 151. The preload of the second spring 155 presses the control valve core 152 firmly onto the shoulder of the control valve seat 151. The main function of the control valve in this disclosure is to perform secondary pressure stabilization on the oil flowing into the first channel 103, ensuring a stable control pressure for the oil entering the first chamber 101, and providing a stable driving force for the precise movement of the main valve core 112.

[0045] The first channel 103 connects to the first chamber 101 sequentially via the control valve core 152 and the communication port 153 on the control valve seat 151; the oil pressure in the control valve seat 151 is configured to push the control valve core 152 to reduce the opening degree of the communication port 153 when it exceeds a third threshold. (Continue to refer to...) Figure 2 and Figure 5The connecting port 153, located on the control valve core 152 and the control valve seat 151, connects the first chamber 101 and the control valve core 152. This allows for communication between the first channel 103 and the first chamber 101, and the flow rate of the oil is controlled by partially blocking the connecting port 153. The third threshold is the equivalent hydraulic pressure value corresponding to the preload of the second spring 155, determined by the stiffness of the second spring 155 and the assembly preload. The third threshold is set to prevent excessive pressure from the oil from the first channel 103 when passing through the connecting port 153, thus preventing excessive pressure from impacting the pilot control unit and damaging it when the oil continues to enter the pilot valve unit. The oil supplied by the first channel 103 flows into the first chamber 101 through the connection port 153 on the control valve core 152 and the control valve seat 151. The oil pressure acts on the end face of the control valve core 152, generating an axial thrust. When this thrust exceeds a third threshold, the control valve core 152 compresses the second spring 155 and moves towards the control valve seat 151. During this process, the opening degree of the connection port 153 on the control valve core 152 and the control valve seat 151 changes, the flow area of ​​the connection port 153 decreases, and the oil flow rate into the first chamber 101 decreases, thereby reducing the pressure in the first chamber 101. This also prevents the main valve core 112 from excessively displacing due to excessive pressure. This structure forms a secondary pressure feedback regulation, further improving the pressure control accuracy and pressure stability of the main valve unit 100.

[0046] In one specific embodiment of this disclosure, reference is made to Figures 1 to 6 When the pilot-operated proportional pressure reducing valve is in operation, the oil enters from the inlet 120 and passes through the inlet channel 121, the return channel 107, and the first channel 103 in sequence into the main valve core 112, flowing towards the first chamber 101. The oil flow rate can be kept constant by controlling the valve core 152. After passing through the control valve core 152, the oil flows into the first chamber 101 from the connecting port 153, and then passes through the first branch 108 and the second branch 208 in sequence, entering the pilot valve chamber 212 from the first inlet 203.

[0047] If the oil pressure in the first chamber 101 and the third chamber 201 is greater than the first threshold and less than the second threshold, the oil continues to flow to the oil passage 214, pushing the conical valve stem 221 to release the seal and enter the fourth chamber 202. Then, it flows through the first outlet 204 on the pilot valve body 211, sequentially through the first drain channel 206 and the drain passage 141, into the drain port 140, and returns to the return oil tank. It is worth mentioning that the return oil port is set separately, and the pressure in the return oil tank is zero.

[0048] If the pressure in the third chamber 201 is greater than the second threshold, the valve core of the protection valve 230 will move to open the second outlet 205, and the oil will flow from the second outlet 205 into the second drain channel 207, merge into the drain channel 141, and finally return to the return oil tank.

[0049] In one embodiment of this disclosure, the main valve chamber 113 extends through one side of the main valve body 111 to form a mounting port 150; the main valve core 112, control valve seat 151, and control valve core 152 extend into the main valve chamber 113 through the mounting port 150. (See reference...) Figure 5 The mounting port 150 is a circular opening penetrating one side of the main valve body 111. Its inner diameter is slightly larger than the outer diameter of the main valve core 112 and the control valve seat 151. The inner wall of the mounting port 150 has a guide chamfer to facilitate the assembly of the main valve core 112, the control valve seat 151, and the control valve core 152. During assembly, the control valve core 152, the second spring 155, and the control valve seat 151 are first assembled into one unit. Then, this assembly and the main valve core 112 are sequentially inserted into the main valve cavity 113 through the mounting port 150. During installation, it is necessary to ensure that the axis of each component coincides with the axis of the main valve cavity 113 to ensure the flexible movement of the main valve core 112 and the control valve core 152. A sealing groove may be provided on the inner wall of the mounting port 150 near the main valve cavity 113 for installing a sealing ring, providing a mating base for the subsequent sealing of the screw plug 156, and preventing oil leakage from the main valve cavity 113 through the mounting port 150.

[0050] Furthermore, in one embodiment of this disclosure, a screw plug 156 is provided at the mounting port 150, and the screw plug 156 seals the main valve core 112, control valve seat 151, and control valve core 152 within the main valve chamber 113. For example... Figure 5 As shown, the plug 156 has a cylindrical structure with an external thread on its outer circumference that matches the internal thread of the mounting port 150. The end face may also have an internal hexagonal groove for easy tightening with tools. The sealing end face of the plug 156 has a sealing ring mounting groove. During assembly, an O-ring or metal sealing ring is placed in the groove. After the plug 156 is screwed into the mounting port 150, the sealing ring is pressed between the end face of the plug 156 and the end face of the mounting port 150, achieving a reliable seal at the mounting port 150. The plug 156, through thread preload, axially positions components such as the main valve core 112, control valve seat 151, and control valve core 152 within the main valve cavity 113, preventing axial displacement of components due to vibration during equipment operation. It also provides removable access for subsequent maintenance; simply unscrewing the plug 156 allows for the removal of internal components for inspection or replacement. This design optimizes the internal structure of the main valve, replacing parts such as the main valve core 112 and the main valve sleeve with cartridge components that can be directly installed from the side of the main valve body 111. This significantly improves the product's versatility and component interchangeability, perfectly meeting the high-efficiency operation and maintenance needs of modern automation systems.

[0051] In one embodiment of this disclosure, the main valve unit 100 further includes a one-way valve 160, which is located within a one-way valve chamber 161 on the main valve body 111. A one-way valve chamber 161 is provided on the main valve body 111 at a position different from the main valve chamber 113. The second inlet 164 of the one-way valve chamber 161 communicates with the oil outlet channel 131 via an oil groove 106; the third outlet 165 of the one-way valve chamber 161 communicates with the oil inlet channel 121 via a return oil groove 107 on the main valve core 112; the one-way valve 160 only allows the passage from the second inlet 164 to the third outlet 165 to be opened. Figure 2 As shown, the second inlet 164 is blocked by the one-way valve core 163. The one-way valve core 163 can be cylindrical or conical in shape and slides in conjunction with the one-way valve seat 162 installed in the one-way valve chamber 161. The elastic component is sleeved on the tail of the one-way valve core 163, with one end abutting against the one-way valve core 163 and the other end abutting against the end of the one-way valve seat 162. The preload of the elastic component causes the one-way valve core 163 to block the second inlet 164 of the one-way valve chamber 161 under normal conditions. When the pressure in the oil outlet channel 131 is higher than the pressure in the oil inlet channel 121, and the pressure difference overcomes the preload of the elastic component, the oil in the oil outlet channel 131 flows into the second inlet 164 through the oil groove 106, pushing the one-way valve core 163 to compress the elastic component and open the passage from the second inlet 164 to the third outlet 165. The oil flows into the return oil groove 107 of the main valve core 112 through the third outlet 165 and finally merges into the oil inlet channel 121. The one-way valve 160 only allows unidirectional flow from the oil outlet channel 131 to the oil inlet channel 121, preventing backflow of oil on the load side from causing a sudden drop in system pressure. It also protects the main valve unit 100 and load components from impact when the system shuts down or the load is suddenly unloaded. This is because the oil from the inlet 120, after passing through the inlet channel 121 and the return groove 107, deviates from the movement trajectory of the one-way valve core 163, thus preventing it from opening the second inlet 164 and ensuring unidirectional flow from the oil outlet channel 131 to the oil inlet channel 121.

[0052] In one specific embodiment of this disclosure, reference is made to Figures 1 to 6When oil return is required, the oil from outlet 130 flows sequentially through outlet channel 131 and annular oil passage 106 to check valve 160. The oil pushes check valve core 163 to open second inlet 164, enters check valve chamber 161, and then sequentially passes through third outlet 165, return oil passage 107, and inlet channel 121, returning to the oil tank connected to inlet 120. If the oil pressure at inlet 120 increases suddenly, some of the oil from outlet 130 flows through damping channel 105 into second channel 104 when passing through oil passage 106, entering second chamber 102. Under the action of pressure difference, it pushes main valve core 112 to move towards first chamber 101. When main valve core 112 moves to the point where oil passage 106 connects with drain channel 141, some of the oil simultaneously flows into drain port 140 and into return tank.

[0053] 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 pilot-operated proportional pressure reducing valve, characterized in that, Includes a main valve unit (100) and a pilot control unit (200) disposed above the main valve unit (100). The main valve unit (100) includes a main valve body (111) and a main valve core (112). The main valve body (111) is configured to have a main valve cavity (113). The main valve core (112) is configured to be movably connected in the main valve cavity (113). One end of the main valve cavity (113) is configured to form a first chamber (101) and the other end forms a second chamber (102). The main valve body (111) is provided with an oil inlet (120), an oil outlet (130), and an oil drain (140); the main valve body (111) is also provided with an oil inlet channel (121) communicating with the oil inlet (120), an oil outlet channel (131) communicating with the oil outlet (130), and an oil drain channel (141) communicating with the oil drain (140); the main valve core (112) is provided with a first channel (103) communicating with the oil inlet channel (121) to the first chamber (101), and a second channel (104) communicating with the oil outlet channel (131) to the second chamber (102); the main valve core (112) is configured to move to the passage communicating with the oil inlet channel (121), the main valve chamber (113), and the oil outlet channel (131) under the pressure difference between the first chamber (101) and the second chamber (102); The pilot control unit (200) includes a pilot valve body (211) and a valve stem (221) controlled by a proportional electromagnet (220). The pilot valve body (211) includes a pilot valve chamber (212) having a first outlet (204) and a pilot valve seat (213) located in the pilot valve chamber (212). The pilot valve seat (213) has a through oil passage (214). The pilot valve chamber (212) has a third chamber (201) communicating with the first chamber (101) and a fourth chamber (202) communicating with the drain passage (141) at both ends of the oil passage (214). The proportional electromagnet (220) is configured to seal the oil passage (214) located in the fourth chamber (202) under the action of a regulating force. When the oil pressure in the first chamber (101) and the third chamber (201) is greater than the first threshold, the valve stem (221) is pushed to open the oil passage (214) so ​​that the oil in the first chamber (101) flows out through the third chamber (201), the oil passage (214), the fourth chamber (202), and the drain passage (141).

2. The pilot-operated proportional pressure reducing valve according to claim 1, characterized in that, A protective valve (230) is provided in the third chamber (201), and the protective valve (230) is provided with a second outlet (205) communicating with the oil drain channel (141); the protective valve (230) is configured to open the second outlet (205) when the pressure in the third chamber (201) is greater than a second threshold; the second threshold is greater than the first threshold.

3. The pilot-operated proportional pressure reducing valve according to claim 1, characterized in that, The main valve core (112) is provided with an oil passage groove (106), and the main valve core (112) is configured to move to the passage connecting the oil inlet channel (121), the oil passage groove (106) and the oil outlet channel (131) under the pressure difference between the first chamber (101) and the second chamber (102).

4. The pilot-operated proportional pressure reducing valve according to claim 1, characterized in that, It also includes a first spring (154), which is located in the first chamber (101); when the pressure of the oil inlet (120) is less than the set pressure of the first spring (154), the first spring (154) holds the main valve core (112) in the initial position to cut off the oil passage between the oil inlet (120) and the oil outlet (130); the main valve core (112) is configured to move to the passage connecting the oil inlet channel (121), the oil groove (106) and the oil outlet channel (131) under the pressure difference of the first chamber (101), the first spring (154) and the second chamber (102).

5. The pilot-operated proportional pressure reducing valve according to claim 4, characterized in that, The main valve core (112) is provided with a damping channel (105) that communicates with the second channel (104); the oil in the oil outlet channel (131) is configured to flow into the second chamber (102) through the oil tank (106), the damping channel (105), and the second channel (104); when the pressure in the second chamber (102) is greater than the force of the first chamber (101) and the first spring (154), the main valve core (112) is pushed to move in the direction of the first chamber (101) so that the oil tank (106) communicates with the oil drain channel (141).

6. The pilot-operated proportional pressure reducing valve according to claim 4, characterized in that, A control valve is provided in the first chamber (101). The control valve includes a control valve seat (151) and a control valve core (152) located in the inner cavity of the control valve seat (151). The control valve core (152) is configured to be pre-pressed in the inner cavity of the control valve seat (151) by a second spring (155). The first channel (103) is configured to communicate with the first chamber (101) in sequence through the control valve core (152) and the communication port (153) provided on the control valve seat (151). The oil pressure in the control valve seat (151) is configured to push the control valve core (152) to move to reduce the opening degree of the communication port (153) when it is greater than a third threshold.

7. The pilot-operated proportional pressure reducing valve according to claim 6, characterized in that, The main valve chamber (113) is configured to form an installation port (150) through one side of the main valve body (111); the main valve core (112), control valve seat (151), and control valve core (152) are configured to extend into the main valve chamber (113) through the installation port (150).

8. The pilot-operated proportional pressure reducing valve according to claim 7, characterized in that, A screw plug (156) is provided at the mounting port (150), the screw plug (156) being configured to seal the main valve core (112), control valve seat (151), and control valve core (152) within the main valve chamber (113).

9. The pilot-operated proportional pressure reducing valve according to claim 3, characterized in that, The main valve unit (100) further includes a one-way valve (160), which is configured to be located in a one-way valve chamber (161) provided on the main valve body (111); the inlet of the one-way valve chamber (161) is configured to communicate with the oil outlet channel (131) via the oil passage (106); the outlet of the one-way valve chamber (161) is configured to communicate with the oil inlet channel (121) via the oil return groove (107) provided on the main valve core (112); the one-way valve (160) is configured to allow only the passage from the inlet to the outlet to be opened.

10. The pilot-operated proportional pressure reducing valve according to claim 1, characterized in that, The valve stem (221) is tapered at one end for sealing or opening the oil passage (214).

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