Pilot-operated type three-way proportional pressure reducing valve

Abstract

The pilot-operated type three-way proportional pressure reducing valve comprises a main valve part and a pilot-operated valve part, the main valve part comprises a main valve body, a main valve element and a reset spring, a main valve cavity is formed in the main valve element, a main valve oil inlet, a main valve oil outlet and a main valve oil drainage opening are formed in the main valve cavity, the main valve element has an initial position, an oil supply position and a pressure relief position, and the pilot-operated valve part is arranged in the initial position. The main valve oil outlet is not communicated with the main valve oil inlet and the main valve oil drainage port under the initial position, and the main valve oil outlet is communicated with the main valve oil inlet under the oil supply position, and hydraulic oil of the main valve oil inlet flows to the main valve oil outlet; in the pressure relief position, the main valve oil outlet is communicated with the main valve oil drainage port, and hydraulic oil of the main valve oil outlet flows to the main valve oil drainage port; the pilot valve part comprises a pilot valve body, a pilot valve core and a proportional electromagnet; the pilot valve element is provided with a pilot closing position and a pilot opening position, and the proportional electromagnet controls the opening pressure of the pilot valve element switched from the pilot closing position to the pilot opening position.

Description

Technical Field

[0001] The present disclosure relates to the field of hydraulic equipment, and more specifically, to a pilot-operated three-way proportional pressure reducing valve. Background Art

[0002] A pressure reducing valve is a valve that reduces inlet pressure to a desired outlet pressure through regulation, automatically maintaining a stable outlet pressure by relying on the energy of the medium itself. Existing pressure reducing valves typically have a two-way structure, which has low pressure reduction efficiency, low stability, and poor performance. Utility Model Content

[0003] In order to solve the problems existing in the prior art, the present disclosure provides a pilot-operated three-way proportional pressure reducing valve.

[0004] According to a first aspect of the present disclosure, there is provided a pilot-operated three-way proportional pressure reducing valve, comprising:

[0005] The main valve portion includes a main valve body, a main valve core and a return spring, a main valve cavity is formed in the main valve core, a main valve oil inlet, a main valve oil outlet and a main valve oil drain port are respectively provided in the main valve cavity, the main valve core has an initial position, an oil supply position and a pressure relief position, in the initial position, the main valve oil outlet is not connected with the main valve oil inlet and the main valve oil drain port, in the oil supply position, the main valve oil outlet is connected with the main valve oil inlet, and the hydraulic oil in the main valve oil inlet flows to the main valve oil outlet; in the pressure relief position, the main valve oil outlet is connected with the main valve oil drain port, and the hydraulic oil in the main valve oil outlet flows to the main valve oil drain port;

[0006] A pilot valve portion, the pilot valve portion comprising a pilot valve body, a pilot valve core and a proportional solenoid, the pilot valve core forming a pilot valve cavity, the pilot valve cavity being provided with at least a pilot valve throttle, the pilot valve throttle being in communication with the main valve oil inlet;

[0007] The pilot valve core has a pilot closing position and a pilot opening position, and the proportional solenoid is configured to control the opening pressure of the pilot valve core when switching from the pilot closing position to the pilot opening position;

[0008] When the pilot valve core is in the pilot closed position, the pilot valve throttle is closed, and the hydraulic oil in the main valve oil inlet overcomes the elastic force of the return spring and pushes the main valve core toward the oil outlet position until the main valve core moves to the oil outlet position;

[0009] When the pressure at the main valve oil outlet reaches the opening pressure, the pilot valve core switches to the pilot opening position, the pilot valve throttle opens, and at least part of the hydraulic oil at the main valve oil inlet flows out from the pilot valve throttle, and the main valve core moves toward the initial position, so that the pressure at the main valve oil outlet is maintained at the opening pressure;

[0010] When the pressure at the main valve oil outlet exceeds the opening pressure, the pilot valve core is in the pilot opening position, the pilot valve throttle port is opened, and the hydraulic oil at the main valve oil outlet at least partially flows out from the pilot valve throttle port. The main valve core moves toward the pressure relief position to connect the main valve oil outlet with the main valve oil drain port, and the pressure at the main valve oil outlet is reduced to the opening pressure.

[0011] In one embodiment of the present disclosure, the return spring includes a first valve core spring arranged on the first side of the main valve core and a second valve core spring arranged on the second side of the main valve core, the first valve core spring is constructed to abut against the inner wall of the first end of the valve body; the second valve core spring is constructed to abut against the inner wall of the second end of the valve body; the first valve core spring and the second valve core spring are constructed to drive the main valve core to restore its initial position.

[0012] In one embodiment of the present disclosure, the main valve core is configured to move from the initial position toward the second side to the oil supply position, and move from the initial position toward the first side to the pressure relief position;

[0013] The main valve body is further configured to form a first spring chamber and a second spring chamber on both sides of the valve core, wherein the first spring chamber is configured to communicate with both the main valve oil inlet and the pilot valve throttle port;

[0014] The second spring chamber is configured to communicate with the main valve oil outlet, and the pressure of the hydraulic oil in the second spring chamber is configured to be only related to the hydraulic oil pressure of the main valve oil outlet.

[0015] In one embodiment of the present disclosure, a valve core through hole is provided on the main valve core, and the valve core through hole is configured to communicate with the first spring chamber through a first damping hole, and communicate with the main valve oil outlet and the second spring chamber.

[0016] In one embodiment of the present disclosure, a three-way portion is formed in the pilot-operated three-way proportional pressure reducing valve; the three-way portion is respectively connected to the main valve oil inlet, the first spring chamber and the pilot valve throttle port.

[0017] In one embodiment of the present disclosure, the three-way portion is connected to the first spring chamber through a second damping hole.

[0018] In one embodiment of the present disclosure, the main valve oil inlet is connected to the three-way portion through a flow control member, and the flow control member is configured to control the flow of hydraulic oil from the main valve oil inlet to the three-way portion.

[0019] In one embodiment of the present disclosure, the pilot valve core is configured with a tapered end and is connected to an output end of the proportional solenoid;

[0020] The pilot valve body comprises a pilot outer valve body and a pilot inner valve body, the pilot inner valve body and the pilot valve core are both arranged in a pilot valve cavity inside the pilot outer valve body, and the pilot valve throttle is formed on the pilot inner valve body;

[0021] When the pilot valve core is in the pilot closing position, the end of the pilot valve core is inserted into the pilot valve throttle port to close the pilot valve throttle port; when the pilot valve core is in the pilot opening position, a throttling gap is formed between the end of the pilot valve core and the pilot valve throttle port to open the pilot valve throttle port.

[0022] In one embodiment of the present disclosure, a pilot valve oil inlet is also provided in the pilot valve cavity. The pilot valve oil inlet is formed on the pilot outer valve body, and one end is connected to the three-way portion, and the other end is connected to the pilot valve throttle port through a passage on the pilot inner valve body.

[0023] In one embodiment of the present disclosure, a pilot valve oil outlet is further provided in the pilot valve chamber, and the pilot valve oil outlet is connected to the main valve oil drain port. The hydraulic oil flowing out of the pilot valve throttle port is constructed to be discharged from the main valve oil drain port through the pilot valve oil outlet.

[0024] The present disclosure provides a pilot-operated three-way proportional pressure reducing valve, comprising a main valve portion and a pilot valve portion. The main valve portion comprises a main valve body, a main valve core and a return spring, a main valve cavity is formed in the main valve core, and a main valve oil inlet, a main valve oil outlet and a main valve oil drain are respectively provided in the main valve cavity. The main valve core has an initial position, an oil supply position and a pressure relief position. In the initial position, the main valve oil outlet is not connected to the main valve oil inlet and the main valve oil drain. In the oil supply position, the main valve oil outlet is connected to the main valve oil inlet, and the hydraulic oil in the main valve oil inlet flows to the main valve oil outlet. In the pressure relief position, the main valve oil outlet is connected to the main valve oil drain, and the hydraulic oil in the main valve oil outlet flows to the main valve oil drain.

[0025] The pilot valve portion includes a pilot valve body, a pilot valve core and a proportional solenoid. A pilot valve cavity is formed in the pilot valve core. At least a pilot valve throttle is provided in the pilot valve cavity. The pilot valve throttle is connected to the oil inlet of the main valve.

[0026] The pilot valve core has a pilot closing position and a pilot opening position, and the proportional solenoid is configured to control the opening pressure of the pilot valve core when switching from the pilot closing position to the pilot opening position.

[0027] When the pilot valve core is in the pilot closed position, the pilot valve throttle port is closed, and the hydraulic oil in the main valve oil inlet overcomes the elastic force of the return spring and pushes the main valve core toward the oil outlet position until the main valve core moves to the oil outlet position.

[0028] When the pressure at the pilot valve throttle port reaches the opening pressure, the pilot valve core switches to the pilot opening position, the pilot valve throttle port opens, and at least part of the hydraulic oil at the main valve oil inlet flows out from the pilot valve throttle port. The main valve core moves to the initial position to keep the pressure at the main valve oil outlet at the opening pressure.

[0029] When the pressure at the pilot valve throttle port exceeds the opening pressure, the pilot valve core is in the pilot opening position, the pilot valve throttle port is opened, and at least part of the hydraulic oil at the main valve oil outlet flows out from the pilot valve throttle port. The main valve core moves to the pressure relief position to connect the main valve oil outlet with the main valve oil drain port, and the pressure at the main valve oil outlet is reduced to the opening pressure.

[0030] That is, in the initial state of the pilot-operated three-way proportional pressure reducing valve disclosed herein, the main valve core is in the initial position, the main valve oil inlet does not provide hydraulic oil, and the main valve oil outlet is not connected to the main valve oil inlet or the main valve oil drain port.

[0031] In the operating state of the pilot-operated three-way proportional pressure reducing valve disclosed herein, the main valve oil inlet begins to supply hydraulic oil, and the proportional solenoid of the pilot valve portion controls the opening pressure of the pilot valve core from the pilot closed position to the pilot open position according to the input. During the process of the main valve oil inlet starting to supply hydraulic oil, the pilot valve core is in the pilot closed position, the pilot valve throttle is closed, and the hydraulic oil in the main valve oil inlet overcomes the elastic force of the return spring and pushes the main valve core in the direction of the oil outlet position until the main valve core moves to the oil outlet position, thereby connecting the main valve oil outlet with the main valve oil inlet, and the hydraulic oil in the main valve oil inlet flows to the main valve oil outlet, thereby achieving the purpose of the main valve oil inlet supplying oil to the main valve oil outlet.

[0032] While the main valve oil inlet continuously supplies oil to the main valve oil outlet, when the pressure at the pilot valve throttle port reaches the opening pressure, the pilot valve core will switch to the pilot opening position, the pilot valve throttle port will open, and at least part of the hydraulic oil at the main valve oil inlet will flow out from the pilot valve throttle port, and the main valve core will move to the initial position, thereby cutting off the main valve oil outlet and the main valve oil inlet, so that the pressure at the main valve oil outlet is maintained at the opening pressure.

[0033] When the pressure at the pilot valve throttle port exceeds the opening pressure, the pilot valve core is in the pilot opening position, the pilot valve throttle port is opened, and at least part of the hydraulic oil at the main valve oil outlet flows out from the pilot valve throttle port. The main valve core moves to the pressure relief position to connect the main valve oil outlet with the main valve oil drain port, and the pressure at the main valve oil outlet is reduced to the opening pressure.

[0034] Compared with the existing pressure reducing valve, the pilot-operated three-way proportional pressure reducing valve disclosed in the present invention controls the pressure rise speed of the main valve oil outlet quickly, and when the secondary pressure at the main valve oil outlet is too high, the pressure drops at a relatively fast rate, and can be applied to working occasions with large flow rates; in general, the control pressure rise and fall times are basically the same, which facilitates the system to maintain constant pressure control; and, the pressure is controlled by the proportional solenoid, with a fast response speed and high precision, and the flow capacity of the pilot valve part is also relatively strong.

[0035] Other features and advantages of the present disclosure will become apparent from the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0037] Figure 1 1 is a cross-sectional schematic diagram of a pilot-operated three-way proportional pressure reducing valve provided by an embodiment of the present disclosure, with the main valve in an initial position;

[0038] Figure 2 1 is a cross-sectional schematic diagram of a pilot-operated three-way proportional pressure reducing valve provided by an embodiment of the present disclosure, with the main valve in the oil supply position;

[0039] Figure 3 1 is a cross-sectional schematic diagram of a pilot-operated three-way proportional pressure reducing valve provided by an embodiment of the present disclosure, with the main valve in a pressure relief position;

[0040] Figures 1 to 3 The corresponding relationship between the component names and reference numerals is as follows:

[0041] 10. Main valve section; 11. Main valve body; 12. Main valve core; 121. Valve core through hole; 122. First damping hole; 131. First valve core spring; 132. Second valve core spring; 133. First spring chamber; 134. Second spring chamber; 14. Main valve chamber; 141. Main valve oil inlet; 142. Main valve oil outlet; 143. Main valve oil drain; 20. Pilot valve section; 21. Pilot valve body; 211. Pilot outer valve body; 212. Pilot inner valve body; 22. Pilot valve core; 23. Proportional solenoid; 24. Pilot valve chamber; 241. Pilot valve throttle; 242. Throttle gap; 243. Pilot valve oil inlet; 244. Pilot valve oil outlet; 31. Three-way section; 32. Second damping hole; 33. Flow control component. DETAILED DESCRIPTION

[0042] 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 numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present disclosure. In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0043] The following description sets forth numerous specific details to facilitate a thorough understanding of the present disclosure. However, the present disclosure can be implemented in many other ways than those described herein, and those skilled in the art may make similar generalizations without violating the scope of the present disclosure. Therefore, the present disclosure is not limited to the specific implementations disclosed below. Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but, where appropriate, such techniques, methods, and apparatus should be considered part of the specification.

[0044] The terms used in one or more embodiments of the present disclosure are for the purpose of describing specific embodiments only and are not intended to limit one or more embodiments of the present disclosure. The singular forms "a", "the", and "the" used in one or more embodiments of the present disclosure and the appended claims are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used in one or more embodiments of the present disclosure refers to and includes any or all possible combinations of one or more associated listed items.

[0045] It should be understood that although the terms first, second, etc. may be used to describe various information in one or more embodiments of the present disclosure, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of one or more embodiments of the present disclosure, the first may also be referred to as the second, and similarly, the second may also be referred to as the first. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determination". In this article, "upper", "lower", "front", "back", "left", "right", etc. are only used to indicate the relative positional relationship between the relevant parts, rather than to limit the absolute position of these relevant parts. In this article, "equal", "same", etc. are not strict mathematical and / or geometric limitations, but also include errors that can be understood by those skilled in the art and are allowed by manufacturing or use. Unless otherwise stated, the numerical ranges herein include not only the entire range within its two endpoints, but also several sub-ranges contained therein.

[0046] The present disclosure provides a pilot-operated three-way proportional pressure reducing valve, comprising a main valve portion and a pilot valve portion. The main valve portion comprises a main valve body, a main valve core and a return spring, a main valve cavity is formed in the main valve core, and a main valve oil inlet, a main valve oil outlet and a main valve oil drain are respectively provided in the main valve cavity. The main valve core has an initial position, an oil supply position and a pressure relief position. In the initial position, the main valve oil outlet is not connected to the main valve oil inlet and the main valve oil drain. In the oil supply position, the main valve oil outlet is connected to the main valve oil inlet, and the hydraulic oil in the main valve oil inlet flows to the main valve oil outlet. In the pressure relief position, the main valve oil outlet is connected to the main valve oil drain, and the hydraulic oil in the main valve oil outlet flows to the main valve oil drain.

[0047] The pilot valve portion includes a pilot valve body, a pilot valve core and a proportional solenoid. A pilot valve cavity is formed in the pilot valve core. At least a pilot valve throttle is provided in the pilot valve cavity. The pilot valve throttle is connected to the oil inlet of the main valve.

[0048] The pilot valve core has a pilot closing position and a pilot opening position, and the proportional solenoid is configured to control the opening pressure of the pilot valve core when switching from the pilot closing position to the pilot opening position.

[0049] When the pilot valve core is in the pilot closed position, the pilot valve throttle port is closed, and the hydraulic oil in the main valve oil inlet overcomes the elastic force of the return spring and pushes the main valve core toward the oil outlet position until the main valve core moves to the oil outlet position.

[0050] When the pressure at the pilot valve throttle port reaches the opening pressure, the pilot valve core switches to the pilot opening position, the pilot valve throttle port opens, and at least part of the hydraulic oil at the main valve oil inlet flows out from the pilot valve throttle port. The main valve core moves to the initial position to keep the pressure at the main valve oil outlet at the opening pressure.

[0051] When the pressure at the pilot valve throttle port exceeds the opening pressure, the pilot valve core is in the pilot opening position, the pilot valve throttle port is opened, and at least part of the hydraulic oil at the main valve oil outlet flows out from the pilot valve throttle port. The main valve core moves to the pressure relief position to connect the main valve oil outlet with the main valve oil drain port, and the pressure at the main valve oil outlet is reduced to the opening pressure.

[0052] That is, in the initial state of the pilot-operated three-way proportional pressure reducing valve disclosed herein, the main valve core is in the initial position, the main valve oil inlet does not provide hydraulic oil, and the main valve oil outlet is not connected to the main valve oil inlet or the main valve oil drain port.

[0053] In the operating state of the pilot-operated three-way proportional pressure reducing valve disclosed herein, the main valve oil inlet begins to supply hydraulic oil, and the proportional solenoid of the pilot valve portion controls the opening pressure of the pilot valve core from the pilot closed position to the pilot open position according to the input. During the process of the main valve oil inlet starting to supply hydraulic oil, the pilot valve core is in the pilot closed position, the pilot valve throttle is closed, and the hydraulic oil in the main valve oil inlet overcomes the elastic force of the return spring and pushes the main valve core in the direction of the oil outlet position until the main valve core moves to the oil outlet position, thereby connecting the main valve oil outlet with the main valve oil inlet, and the hydraulic oil in the main valve oil inlet flows to the main valve oil outlet, thereby achieving the purpose of the main valve oil inlet supplying oil to the main valve oil outlet.

[0054] While the main valve oil inlet continuously supplies oil to the main valve oil outlet, when the pressure at the pilot valve throttle port reaches the opening pressure, the pilot valve core will switch to the pilot opening position, the pilot valve throttle port will open, and at least part of the hydraulic oil at the main valve oil inlet will flow out from the pilot valve throttle port, and the main valve core will move to the initial position, thereby cutting off the main valve oil outlet and the main valve oil inlet, so that the pressure at the main valve oil outlet is maintained at the opening pressure.

[0055] When the pressure at the pilot valve throttle port exceeds the opening pressure, the pilot valve core is in the pilot opening position, the pilot valve throttle port is opened, and at least part of the hydraulic oil at the main valve oil outlet flows out from the pilot valve throttle port. The main valve core moves to the pressure relief position to connect the main valve oil outlet with the main valve oil drain port, and the pressure at the main valve oil outlet is reduced to the opening pressure.

[0056] Compared with the existing pressure reducing valve, the pilot-operated three-way proportional pressure reducing valve disclosed in the present invention controls the pressure rise speed of the main valve oil outlet quickly, and when the secondary pressure at the main valve oil outlet is too high, the pressure drops at a relatively fast rate, and can be applied to working occasions with large flow rates; in general, the control pressure rise and fall times are basically the same, which facilitates the system to maintain constant pressure control; and, the pressure is controlled by the proportional solenoid, with a fast response speed and high precision, and the flow capacity of the pilot valve part is also relatively strong.

[0057] For ease of understanding, refer to Figures 1 to 3, the specific structure and working principle of the pilot-operated three-way proportional pressure reducing valve disclosed in the present invention are explained in detail with reference to an embodiment.

[0058] like Figures 1 to 3 As shown, the present disclosure provides a pilot-operated three-way proportional pressure reducing valve, comprising a main valve portion 10 and a pilot valve portion 20 . Wherein, the main valve portion 10 includes a main valve body 11, a main valve core 12 and a return spring, a main valve cavity 14 is formed in the main valve core 12, and a main valve oil inlet 141, a main valve oil outlet 142 and a main valve oil drain port 143 are respectively provided in the main valve cavity 14, and the main valve core 12 has an initial position, an oil supply position and a pressure relief position. In the initial position, the main valve oil outlet 142 is not connected with the main valve oil inlet 141 and the main valve oil drain port 143. In the oil supply position, the main valve oil outlet 142 is connected with the main valve oil inlet 141, and the hydraulic oil in the main valve oil inlet 141 flows to the main valve oil outlet 142; in the pressure relief position, the main valve oil outlet 142 is connected with the main valve oil drain port 143, and the hydraulic oil in the main valve oil outlet 142 flows to the main valve oil drain port 143;

[0059] The pilot valve portion 20 includes a pilot valve body 21 , a pilot valve core 22 and a proportional solenoid 23 . A pilot valve cavity 24 is formed in the pilot valve core 22 . At least a pilot valve throttle port 241 is provided in the pilot valve cavity 24 . The pilot valve throttle port 241 is connected to the main valve oil inlet 141 .

[0060] The pilot spool 22 has a pilot closed position and a pilot open position, and the proportional solenoid 23 is configured to control the opening pressure for switching the pilot spool 22 from the pilot closed position to the pilot open position.

[0061] The pilot valve core 22 is in the pilot closed position, the pilot valve throttle port 241 is closed, and the hydraulic oil in the main valve oil inlet 141 overcomes the elastic force of the return spring to push the main valve core 12 toward the oil outlet position until the main valve core 12 moves to the oil outlet position.

[0062] When the pressure of the pilot valve throttle port 241 reaches the opening pressure, the pilot valve core 22 switches to the pilot opening position, the pilot valve throttle port 241 opens, and the hydraulic oil of the main valve oil inlet 141 at least partially flows out from the pilot valve throttle port 241, and the main valve core 12 moves to the initial position to keep the pressure of the main valve oil outlet 142 at the opening pressure.

[0063] When the pressure of the pilot valve throttle port 241 exceeds the opening pressure, the pilot valve core 22 is in the pilot opening position, the pilot valve throttle port 241 is opened, and the hydraulic oil in the main valve oil outlet 142 at least partially flows out from the pilot valve throttle port 241, and the main valve core 12 moves to the pressure relief position to connect the main valve oil outlet 142 with the main valve oil drain port 143, and the pressure of the main valve oil outlet 142 is reduced to the opening pressure.

[0064] That is Figure 1 As shown, in the initial state of the pilot-operated three-way proportional pressure reducing valve disclosed herein, the main valve core 12 is in the initial position, the main valve oil inlet 141 does not provide hydraulic oil, and the main valve oil outlet 142 is not connected to the main valve oil inlet 141 and the main valve oil drain port 143.

[0065] like Figure 2 As shown, in the working state of the pilot-operated three-way proportional pressure reducing valve disclosed herein, the main valve oil inlet 141 begins to supply hydraulic oil, and the proportional solenoid 23 of the pilot valve portion 20 controls the opening pressure of the pilot valve core 22 from the pilot closed position to the pilot open position according to the input. When the main valve oil inlet 141 begins to supply hydraulic oil, the pilot valve core 22 is in the pilot closed position, the pilot valve throttle 241 is closed, and the hydraulic oil in the main valve oil inlet 141 overcomes the elastic force of the return spring and pushes the main valve core 12 in the direction of the oil outlet position until the main valve core 12 moves to the oil outlet position, thereby connecting the main valve oil outlet 142 with the main valve oil inlet 141. The hydraulic oil in the main valve oil inlet 141 flows to the main valve oil outlet 142, thereby achieving the purpose of supplying oil from the main valve oil inlet 141 to the main valve oil outlet 142.

[0066] While the main valve oil inlet 141 continuously supplies oil to the main valve oil outlet 142, when the pressure of the pilot valve throttle port 241 reaches the opening pressure, the pilot valve core 22 is in the pilot opening position, the pilot valve throttle port 241 is opened, and the hydraulic oil of the main valve oil inlet 141 at least partially flows out from the pilot valve throttle port 241, and the main valve core 12 moves to the initial position, thereby causing the main valve core 12 to move to the initial position, cutting off the main valve oil outlet 142 and the main valve oil inlet 141, so that the pressure of the main valve oil outlet 142 is maintained at the opening pressure.

[0067] And as Figure 3 As shown, when the pressure of the pilot valve throttle port 241 exceeds the opening pressure, the pilot valve core 22 is in the pilot opening position, the pilot valve throttle port 241 is opened, and the hydraulic oil in the main valve oil outlet 142 at least partially flows out from the pilot valve throttle port 241, and the main valve core 12 moves to the pressure relief position to connect the main valve oil outlet 142 with the main valve oil drain port 143, and the pressure of the main valve oil outlet 142 is reduced to the opening pressure.

[0068] Compared with the existing pressure reducing valve, the pilot-operated three-way proportional pressure reducing valve disclosed in the present invention controls the pressure rise speed of the main valve oil outlet 142 quickly, and when the secondary pressure at the main valve oil outlet 142 is too high, the pressure drops at a relatively fast rate, and can be applied to working occasions with a large flow rate; in general, the control pressure rise and fall time are basically the same, which facilitates the system to maintain constant pressure control; and, the pressure is controlled by the proportional solenoid 23, with a fast response speed and high precision, and the flow capacity of the pilot valve part 20 is also relatively strong.

[0069] like Figure 1 As shown, in one embodiment of the present disclosure, the return spring includes a first valve core spring 131 disposed on a first side of the main valve core 12 and a second valve core spring 132 disposed on a second side of the main valve core 12. The first valve core spring 131 is configured to abut against the inner wall of the first end of the valve body; the second valve core spring 132 is configured to abut against the inner wall of the second end of the valve body. The first valve core spring 131 and the second valve core spring 132 are configured to drive the main valve core 12 to return to its initial position. By providing the first valve core spring 131 and the second valve core spring 132 on both sides of the valve core, the main valve core 12 can be driven to return to its initial position even when oil is not supplied to the main valve oil inlet 141 of the pilot-operated three-way proportional pressure reducing valve of the present disclosure.

[0070] like Figure 1 As shown, in one embodiment of the present disclosure, the main valve core 12 is constructed to move from the initial position toward the second side direction to the oil supply position, and move from the initial position toward the first side direction to the pressure relief position; the main valve body 11 is also constructed to form a first spring chamber 133 and a second spring chamber 134 on both sides of the valve core, and the first spring chamber 133 is constructed to be connected to the main valve oil inlet 141 and the pilot valve throttle port 241; the second spring chamber 134 is constructed to be connected to the main valve oil inlet 141, and the pressure of the hydraulic oil in the second spring chamber 134 is configured to be related only to the hydraulic oil pressure of the main valve oil outlet 142.

[0071] It can be understood that when the pressure of the hydraulic oil in the first spring chamber 133 is greater than the pressure of the hydraulic oil in the second spring chamber 134, the main valve core 12 can move from the initial position to the second side direction to the oil supply position, so that the main valve oil outlet 142 is connected with the main valve oil inlet 141, and the hydraulic oil in the main valve oil inlet 141 flows to the main valve oil outlet 142; when the pressure of the hydraulic oil in the second spring chamber 134 is greater than the pressure of the hydraulic oil in the first spring chamber 133, the main valve core 12 can move from the initial position to the first side direction to the pressure relief position, so that the main valve oil outlet 142 is connected with the main valve oil drain port 143, and the hydraulic oil in the main valve oil outlet 142 flows to the main valve oil drain port 143.

[0072] Since the first spring chamber 133 is connected to the main valve oil inlet 141 and the pilot valve throttle port 241; the second spring chamber 134 is connected to the main valve oil outlet 142, the pressure of the hydraulic oil in the second spring chamber 134 is configured to be only related to the hydraulic oil pressure of the main valve oil outlet 142.

[0073] When the main valve oil inlet 141 starts to provide hydraulic oil, the pilot valve core 22 is in the pilot closing position, the pilot valve throttle port 241 is closed, and the hydraulic oil in the main valve oil inlet 141 can flow to the first spring chamber 133. There is basically no hydraulic oil in the second spring chamber 134, and the pressure is relatively low. The pressure of the hydraulic oil in the first spring chamber 133 is greater than the pressure of the hydraulic oil in the second spring chamber 134. The hydraulic oil in the first spring chamber 133 can push the main valve core 12 in the direction of the second spring chamber 134 until the main valve core 12 moves to the oil outlet position, thereby connecting the main valve oil outlet 142 with the main valve oil inlet 141, thereby achieving the purpose of supplying oil from the main valve oil inlet 141 to the main valve oil outlet 142. During this process, the hydraulic oil in the main valve oil inlet 141 flows to the main valve oil outlet 142, and flows from the main valve oil outlet 142 to the second spring chamber 134. The pressure in the second spring chamber 134 continues to increase. When the pressure in the second spring chamber 134 continues to increase, the main valve core 12 will continue to move toward the direction of the first spring chamber 133, and the hydraulic oil in the first spring chamber 133 will gradually decrease.

[0074] In the above process, since the main valve oil inlet 141 is connected to the pilot valve throttle port 241, when the pressure at the pilot valve throttle port 241 reaches the opening pressure, the hydraulic oil at the main valve oil inlet 141 can push the pilot valve core 22, and the pilot valve core 22 will switch to the pilot opening position. The pilot valve throttle port 241 will open, and the hydraulic oil at the main valve oil inlet 141 will partially flow out from the pilot valve throttle port 241 and partially flow into the main valve oil outlet 142 until the pressure of the hydraulic oil in the first spring chamber 133 is equal to the pressure of the hydraulic oil in the second spring chamber 134, and the main valve core 12 returns to its initial position, cutting off the main valve oil inlet 141 and the main valve oil outlet 142. All the hydraulic oil at the main valve oil inlet 141 flows out from the pilot valve throttle port 241, and the pressure balance is maintained between the main valve oil inlet 141 and the main valve oil outlet 142.

[0075] When the pressure at the main valve oil outlet 142 is too high, resulting in the pressure of the hydraulic oil in the second spring chamber 134 being greater than the pressure of the hydraulic oil in the first spring chamber 133, the hydraulic oil in the second spring chamber 134 can push the main valve core 12 toward the direction of the first spring chamber 133, and the hydraulic oil in the first spring chamber 133 can continuously flow to the pilot valve throttle port 241 and push the pilot valve core 22 to maintain the pilot open position. The pilot valve throttle port 241 is opened, and the liquid in the first spring chamber 133 is opened. The pressurized oil flows out from the pilot valve throttle port 241, and the main valve core 12 is continuously pushed toward the direction of the first spring chamber 133 until the main valve oil outlet 142 is connected with the main valve oil drain port 143. After the pressure of the main valve oil outlet 142 is quickly reduced to the opening pressure, the main valve core 12 returns to its initial position, cutting off the main valve oil outlet 142 and the main valve oil drain port 143. The hydraulic oil in the first spring chamber 133 no longer continues to flow out, and the pressure balance is maintained between the main valve oil inlet 141 and the main valve oil outlet 142.

[0076] By setting the above structure, the pressure changes in the first spring chamber 133 and the second spring chamber 134 can be effectively utilized to realize the position movement of the main valve core 12 of the present disclosure, thereby quickly realizing state switching, and the pressure increase and pressure reduction speeds are relatively fast, the efficiency is high, and the pressure control accuracy is high.

[0077] like Figure 1 As shown, in one embodiment of the present disclosure, the main valve core 12 is provided with a valve core through-hole 121. The valve core through-hole 121 is configured to communicate with the first spring chamber 133 through a first damping orifice 122, and is further connected to the main valve oil outlet 142 and the second spring chamber 134. Because the valve core through-hole 121 communicates with the first spring chamber 133 through the first damping orifice 122, a certain pressure differential can be maintained between the valve core through-hole 121 and the first spring chamber 133. Therefore, by controlling the size of the first damping orifice 122, the pilot-operated three-way proportional pressure reducing valve of the present disclosure can maintain pressure increase and pressure reduction for a period of time, making the pressure increase and pressure reduction process more stable, with less oscillation and high pressure control accuracy.

[0078] Specifically, when the main valve oil inlet 141 starts to supply hydraulic oil, the pilot valve core 22 is in the pilot closed position, the pilot valve throttle port 241 is closed, and the hydraulic oil in the main valve oil inlet 141 can flow to the first spring chamber 133. There is basically no hydraulic oil in the second spring chamber 134, and the pressure is relatively low. Since the first spring chamber 133 is connected to the first spring chamber 133 through the first damping hole 122, a small amount of hydraulic oil will enter the valve core through-hole 121 from the first spring chamber 133, and then flow into the main valve oil outlet 142 and the second spring chamber 134. However, the pressure of the hydraulic oil in the first spring chamber 133 can still be kept greater than the pressure of the hydraulic oil in the second spring chamber 134, so that the hydraulic oil in the first spring chamber 133 can push the main valve core 12 in the direction of the second spring chamber 134 until the main valve core 12 moves to the oil outlet position. The main valve oil outlet 142 is connected with the main valve oil inlet 141; after the main valve oil outlet 142 is connected with the main valve oil inlet 141, a large amount of hydraulic oil will flow from the main valve oil inlet 141 to the main valve oil outlet 142, and then flow to the valve core through hole 121 and the second spring chamber 134, and the pressure in the second spring chamber 134 will continue to increase. When the pressure in the second spring chamber 134 continues to increase, the main valve core 12 will continue to move toward the direction of the first spring chamber 133, and the hydraulic oil in the first spring chamber 133 will gradually decrease.

[0079] In the above process, since the main valve oil inlet 141 is connected to the pilot valve throttle port 241, when the pressure at the pilot valve throttle port 241 reaches the opening pressure, the hydraulic oil at the main valve oil inlet 141 can push the pilot valve core 22, and the pilot valve core 22 will switch to the pilot opening position. The pilot valve throttle port 241 will open, and the hydraulic oil at the main valve oil inlet 141 will partially flow out from the pilot valve throttle port 241 and partially flow into the main valve oil outlet 142 until the pressure of the hydraulic oil in the first spring chamber 133 is equal to the pressure of the hydraulic oil in the second spring chamber 134, and the main valve core 12 returns to its initial position, cutting off the main valve oil inlet 141 and the main valve oil outlet 142. All the hydraulic oil at the main valve oil inlet 141 flows out from the pilot valve throttle port 241, and the pressure balance is maintained between the main valve oil inlet 141 and the main valve oil outlet 142.

[0080] When the pressure at the main valve oil outlet 142 is too high, since the first spring chamber 133 is connected to the first spring chamber 133 through the first damping hole 122, a small amount of hydraulic oil will enter the first spring chamber 133 from the valve core through hole 121, but the pressure of the hydraulic oil in the second spring chamber 134 can still be kept greater than the pressure of the hydraulic oil in the first spring chamber 133. The hydraulic oil in the second spring chamber 134 can push the main valve core 12 toward the direction of the first spring chamber 133, and the hydraulic oil in the first spring chamber 133 can continuously flow to the pilot valve throttle port 241 and push the pilot valve core 22 to maintain the pilot open position. The pilot valve throttle port 241 is opened, and the hydraulic oil in the first spring chamber 133 flows out from the pilot valve throttle port 241. The main valve core 12 is continuously pushed toward the direction of the first spring chamber 133 until the main valve oil outlet 142 is connected with the main valve oil drain port 143. After the pressure of the main valve oil outlet 142 is quickly reduced to the opening pressure, the pressure of the hydraulic oil in the second spring chamber 134 is equal to the pressure of the hydraulic oil in the first spring chamber 133. The main valve core 12 returns to its initial position, cutting off the main valve oil outlet 142 and the main valve oil drain port 143, and maintaining pressure balance between the main valve oil inlet 141 and the main valve oil outlet 142.

[0081] Specifically, such as Figure 1 As shown, in one embodiment of the present disclosure, a three-way portion 31 is formed within the pilot-operated three-way proportional pressure-reducing valve; the three-way portion 31 is respectively in communication with the main valve oil inlet 141, the first spring chamber 133, and the pilot valve throttle 241. By forming the three-way portion 31 within the pilot-operated three-way proportional pressure-reducing valve, the three-way portion 31 is respectively in communication with the main valve oil inlet 141, the first spring chamber 133, and the pilot valve throttle 241, thereby facilitating communication between the main valve oil inlet 141, the first spring chamber 133, and the pilot valve throttle 241.

[0082] Further, such as Figure 1 As shown, in one embodiment of the present disclosure, the three-way portion 31 is in communication with the first spring chamber 133 via the second damping hole 32. Since the three-way portion 31 is in communication with the first spring chamber 133 via the second damping hole 32, a certain pressure differential can be maintained during the process in which the hydraulic oil at the main valve oil inlet 141 flows into the first spring chamber 133 through the three-way portion 31 and the second damping hole 32, and the hydraulic oil in the first spring chamber 133 flows into the pilot valve throttle port 241 through the second damping hole 32 and the three-way portion 31, thereby making the pressure increase and pressure reduction process more stable.

[0083] like Figure 1As shown, in one embodiment of the present disclosure, the main valve oil inlet 141 is connected to the three-way portion 31 through the flow control member 33, and the flow control member 33 is configured to control the flow rate of hydraulic oil flowing from the main valve oil inlet 141 to the three-way portion 31. Since the main valve oil inlet 141 is connected to the three-way portion 31 through the flow control member 33, the flow control member 33 can control the flow rate of hydraulic oil flowing from the main valve oil inlet 141 to the three-way portion 31. This can ensure that when the main valve oil inlet 141 is supplying oil to the main valve oil outlet 142, a small portion of the hydraulic oil provided by the main valve oil inlet 141 flows through the three-way portion 31 to the pilot valve portion 20 and the first spring chamber 133, while most of the hydraulic oil flows directly into the main valve oil outlet 142, thereby effectively improving the oil supply efficiency.

[0084] like Figure 1 As shown, in one embodiment of the present disclosure, the pilot valve core 22 is constructed with a conical end and is connected to the output end of the proportional solenoid 23; the pilot valve body 21 includes a pilot outer valve body 211 and a pilot inner valve body 212, the pilot inner valve body 212 and the pilot valve core 22 are both arranged in the pilot valve cavity 24 inside the pilot outer valve body 211, and the pilot valve throttle port 241 is formed on the pilot inner valve body 212; when the pilot valve core 22 is in the pilot closed position, the end of the pilot valve core 22 is inserted into the pilot valve throttle port 241 to close the pilot valve throttle port 241; when the pilot valve core 22 is in the pilot open position, a throttling gap 242 is formed between the end of the pilot valve core 22 and the pilot valve throttle port 241 to open the pilot valve throttle port 241.

[0085] In this way, when the pilot valve core 22 needs to be in the pilot closed position, the tapered end of the pilot valve core 22 is inserted into the pilot valve throttle port 241 to close the pilot valve throttle port 241 and prevent leakage; and when the pilot valve core 22 needs to be in the pilot open position, a throttling gap 242 can be quickly formed between the tapered end of the pilot valve core 22 and the pilot valve throttle port 241, so as to quickly open the pilot valve throttle port 241.

[0086] like Figure 1 As shown, in one embodiment of the present disclosure, a pilot valve oil inlet 243 is further provided in the pilot valve chamber 24. The pilot valve oil inlet 243 is formed on the pilot outer valve body 211, and one end of the pilot valve oil inlet 243 is connected to the three-way portion 31, and the other end is connected to the pilot valve throttle port 241 through a passage on the pilot inner valve body 212. By providing the pilot valve oil inlet 243 on the pilot outer valve body 211, one end of the pilot valve oil inlet 243 is connected to the three-way portion 31, and the other end is connected to the pilot valve throttle port 241 through a passage on the pilot inner valve body 212, thereby achieving the purpose of connecting the pilot valve throttle port 241 to the three-way portion 31.

[0087] like Figure 1As shown, in one embodiment of the present disclosure, a pilot valve oil outlet 244 is further provided in the pilot valve chamber 24. The pilot valve oil outlet 244 is communicated with the main valve oil drain port 143. The hydraulic oil flowing out of the pilot valve throttle port 241 is configured to be discharged from the main valve oil drain port 143 through the pilot valve oil outlet 244. In this way, the hydraulic oil flowing out of the pilot valve throttle port 241 is discharged from the main valve oil drain port 143 through the pilot valve oil outlet 244, eliminating the need to provide a separate oil drain port for the pilot valve, which is more convenient.

[0088] In one embodiment of the present disclosure, the proportional solenoid 23 is configured to control the opening pressure of the pilot valve spool 22 when switching from the pilot closed position to the pilot open position based on an input current. Controlling the opening pressure of the pilot valve spool 22 when switching from the pilot closed position to the pilot open position based on the input current is more convenient and offers high adjustment accuracy. In another embodiment of the present disclosure, other parameters may be used to control the opening pressure of the pilot valve spool 22 when switching from the pilot closed position to the pilot open position, without limitation.

[0089] The embodiments of the present disclosure have been described above. The above description is exemplary, not exhaustive, and is 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 terms used herein are selected to best explain the principles of the embodiments, their practical applications, or technical improvements in the marketplace, or to enable other persons skilled in the art to understand the embodiments disclosed herein. The scope of the present disclosure is defined by the appended claims.

Claims

1. A pilot-operated three-way proportional pressure reducing valve, characterized in that: include: The main valve portion (10) includes a main valve body (11), a main valve core (12) and a return spring. A main valve cavity (14) is formed in the main valve core (12). A main valve oil inlet (141), a main valve oil outlet (142) and a main valve oil drain (143) are respectively provided in the main valve cavity (14). The main valve core (12) has an initial position, an oil supply position and a pressure relief position. In the initial position, the main valve oil outlet (142) is in contact with the main valve inlet. The oil port (141) and the main valve oil drain port (143) are not connected. When in the oil supply position, the main valve oil outlet (142) is connected to the main valve oil inlet (141), and the hydraulic oil in the main valve oil inlet (141) flows to the main valve oil outlet (142); when in the pressure relief position, the main valve oil outlet (142) is connected to the main valve oil drain port (143), and the hydraulic oil in the main valve oil outlet (142) flows to the main valve oil drain port (143); A pilot valve portion (20), the pilot valve portion (20) comprising a pilot valve body (21), a pilot valve core (22) and a proportional solenoid (23), a pilot valve cavity (24) being formed in the pilot valve core (22), at least a pilot valve throttle (241) being provided in the pilot valve cavity (24), the pilot valve throttle (241) being communicated with the main valve oil inlet (141); The pilot valve core (22) has a pilot closing position and a pilot opening position, and the proportional solenoid (23) is configured to control the opening pressure of the pilot valve core (22) when switching from the pilot closing position to the pilot opening position; When the pilot valve core (22) is in the pilot closed position, the pilot valve throttle port (241) is closed, and the hydraulic oil in the main valve oil inlet (141) overcomes the elastic force of the return spring and pushes the main valve core (12) toward the oil outlet position until the main valve core (12) moves to the oil outlet position; When the pressure at the main valve oil outlet (142) reaches the opening pressure, the pilot valve core (22) switches to the pilot opening position, the pilot valve throttle (241) opens, and at least part of the hydraulic oil at the main valve oil inlet (141) flows out from the pilot valve throttle (241), and the main valve core (12) moves to the initial position, so that the pressure at the main valve oil outlet (142) is maintained at the opening pressure; When the pressure of the main valve oil outlet (142) exceeds the opening pressure, the pilot valve core (22) is in the pilot opening position, the pilot valve throttle port (241) is opened, and the hydraulic oil of the main valve oil outlet (142) at least partially flows out from the pilot valve throttle port (241), and the main valve core (12) moves to the pressure relief position to connect the main valve oil outlet (142) with the main valve oil drain port (143), and the pressure of the main valve oil outlet (142) is reduced to the opening pressure.

2. The pilot-operated three-way proportional pressure reducing valve according to claim 1, characterized in that: The return spring includes a first valve core spring (131) arranged on the first side of the main valve core (12) and a second valve core spring (132) arranged on the second side of the main valve core (12), the first valve core spring (131) being configured to abut against the inner wall of the first end of the valve body; the second valve core spring (132) being configured to abut against the inner wall of the second end of the valve body; the first valve core spring (131) and the second valve core spring (132) being configured to drive the main valve core (12) to return to its initial position.

3. The pilot-operated three-way proportional pressure reducing valve according to claim 2, characterized in that: The main valve core (12) is configured to move from the initial position toward the second side to the oil supply position, and from the initial position toward the first side to the pressure relief position; The main valve body (11) is further configured to form a first spring chamber (133) and a second spring chamber (134) on both sides of the valve core, wherein the first spring chamber (133) is configured to communicate with both the main valve oil inlet (141) and the pilot valve throttle port (241); The second spring chamber (134) is configured to communicate with the main valve oil outlet (142), and the pressure of the hydraulic oil in the second spring chamber (134) is configured to be only related to the hydraulic oil pressure of the main valve oil outlet (142).

4. The pilot-operated three-way proportional pressure reducing valve according to claim 3, characterized in that: The main valve core (12) is provided with a valve core through hole (121), and the valve core through hole (121) is configured to communicate with the first spring chamber (133) through a first damping hole (122), and to communicate with the main valve oil outlet (142) and the second spring chamber (134).

5. The pilot-operated three-way proportional pressure reducing valve according to claim 3, characterized in that: A three-way portion (31) is formed in the pilot-operated three-way proportional pressure reducing valve; the three-way portion (31) is respectively connected to the main valve oil inlet (141), the first spring chamber (133) and the pilot valve throttle port (241).

6. The pilot-operated three-way proportional pressure reducing valve according to claim 5, characterized in that: The three-way portion (31) is connected to the first spring chamber (133) through a second damping hole (32).

7. The pilot-operated three-way proportional pressure reducing valve according to claim 5, characterized in that: The main valve oil inlet (141) is connected to the three-way portion (31) through a flow control member (33), and the flow control member (33) is configured to control the flow of hydraulic oil flowing from the main valve oil inlet (141) to the three-way portion (31).

8. The pilot-operated three-way proportional pressure reducing valve according to claim 5, characterized in that: The pilot valve core (22) is configured with a tapered end and is connected to the output end of the proportional solenoid (23); The pilot valve body (21) comprises a pilot outer valve body (211) and a pilot inner valve body (212), the pilot inner valve body (212) and the pilot valve core (22) are both arranged in a pilot valve cavity (24) inside the pilot outer valve body (211), and the pilot valve throttle (241) is formed on the pilot inner valve body (212); When the pilot valve core (22) is in the pilot closing position, the end of the pilot valve core (22) is inserted into the pilot valve throttle port (241) so that the pilot valve throttle port (241) is closed; when the pilot valve core (22) is in the pilot opening position, a throttling gap (242) is formed between the end of the pilot valve core (22) and the pilot valve throttle port (241) so that the pilot valve throttle port (241) is opened.

9. The pilot-operated three-way proportional pressure reducing valve according to claim 8, characterized in that: A pilot valve oil inlet (243) is also provided in the pilot valve chamber (24). The pilot valve oil inlet (243) is formed on the pilot outer valve body (211), and one end of the pilot valve oil inlet (243) is connected to the three-way portion (31), and the other end of the pilot valve oil inlet (243) is connected to the pilot valve throttle port (241) through a passage on the pilot inner valve body (212).

10. The pilot-operated three-way proportional pressure reducing valve according to claim 8, characterized in that: A pilot valve oil outlet (244) is also provided in the pilot valve chamber (24). The pilot valve oil outlet (244) is communicated with the main valve oil drain port (143). The hydraulic oil flowing out of the pilot valve throttle port (241) is configured to be discharged from the main valve oil drain port (143) through the pilot valve oil outlet (244).

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