Pilot-operated type proportional overflow valve

Abstract

The pilot-operated type proportional overflow valve comprises a main valve part and a pilot valve part, the main valve part comprises a main valve body, a main valve element and a main valve reset spring, a main valve cavity is formed in the main valve element, a main valve oil inlet and a main valve oil outlet are formed in the main valve cavity, when the main valve element is located at the first main valve position, the main valve oil inlet communicates with the main valve oil outlet, and when the main valve element is located at the second main valve position, the main valve oil inlet communicates with the main valve oil outlet; in the second main valve position, the main valve oil inlet and the main valve oil outlet are disconnected; the pilot valve part comprises a pilot valve body, a pilot valve core and a proportional electromagnet; when the pilot valve element is located at the third pilot valve position, hydraulic oil of the main valve oil inlet overcomes the elastic force of the main valve reset spring to push the main valve element in the direction where the first main valve position is located; in the fourth pilot valve position, hydraulic oil of an oil inlet of the pilot valve flows to a spring cavity of the main valve; the hydraulic oil of the main valve oil inlet overcomes the elastic force of the main valve reset spring and the pressure of the hydraulic oil in the main valve spring cavity to push the main valve element in the direction of the first main valve position.

Description

Technical Field

[0001] The present disclosure relates to the field of hydraulic equipment, and more precisely, to a pilot-operated proportional relief valve. Background Art

[0002] Most of the relief valves used in existing hydraulic transmission systems adopt traditional mechanical structures rather than computer control. The proportional relief valves controlled by computers have complex structures and are not applicable to some hydraulic transmission systems. Moreover, the control part has a relatively complex structure, which is not easy for operators to master, has multiple faults, is not easy to repair, and has high maintenance costs. Summary of the Utility Model

[0003] The present disclosure provides a pilot-operated proportional relief valve to solve the problems existing in the prior art.

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

[0005] A main valve part, the main valve part includes a main valve body, a main valve core and a main valve return spring. A main valve cavity is formed in the main valve core. A main valve inlet and a main valve outlet are respectively arranged in the main valve cavity. The main valve core has a first main valve position and a second main valve position. When in the first main valve position, the main valve inlet and the main valve outlet are communicated. When in the second main valve position, the main valve inlet and the main valve outlet are disconnected. The main valve return spring is located in the main valve spring cavity and is configured to push the main valve core in the direction of the second main valve position. The hydraulic oil at the main valve inlet is configured to push the main valve core in the direction of the first main valve position.

[0006] A pilot valve part, the pilot valve part includes a pilot valve body, a pilot valve core and a proportional electromagnet. A pilot valve cavity is formed in the pilot valve core. At least a pilot valve inlet is arranged in the pilot valve cavity. The pilot valve core has a third pilot valve position and a fourth pilot valve position. The proportional electromagnet is configured to move the pilot valve core between the third pilot valve position and the fourth pilot valve position.

[0007] When the pilot valve core is in the third pilot valve position, the pilot valve inlet is closed, and the hydraulic oil at the main valve inlet is configured to push the main valve core in the direction of the first main valve position against the elastic force of the main valve return spring.

[0008] When the pilot valve spool is in the fourth pilot valve position, the pilot valve inlet port is opened and is communicated with the main valve spring chamber through a communication pipeline, and the hydraulic oil at the pilot valve inlet port is configured to flow to the main valve spring chamber; the hydraulic oil at the main valve inlet port is configured to push the main valve spool in the direction of the first main valve position by overcoming the elastic force of the main valve return spring and the pressure of the hydraulic oil in the main valve spring chamber.

[0009] In an embodiment of the present disclosure, a pilot valve oil return port is further provided in the pilot valve chamber; when the pilot valve spool is in the third pilot valve position, the pilot valve oil return port is communicated with the main valve spring chamber through a communication pipeline, and the hydraulic oil in the main valve spring chamber is configured to at least partially flow to the pilot valve oil return port; when the pilot valve spool is in the fourth pilot valve position, the pilot valve oil return port is disconnected from the communication pipeline.

[0010] In an embodiment of the present disclosure, a pilot proportional pressure reducing outlet is further provided in the pilot valve chamber; when the pilot valve spool is in the third pilot valve position, the pilot valve oil return port is communicated with the pilot proportional pressure reducing outlet; when the pilot valve spool is in the fourth pilot valve position, the pilot valve inlet port is communicated with the pilot proportional pressure reducing outlet, the pilot valve inlet port is opened, and is communicated with the main valve spring chamber through the pilot proportional pressure reducing outlet and a communication pipeline, and the hydraulic oil at the pilot valve inlet port is configured to flow to the main valve spring chamber;

[0011] The proportional electromagnet is configured to control the opening degree of the pilot proportional pressure reducing outlet based on the input current.

[0012] In an embodiment of the present disclosure, an oil drain port for the electromagnet chamber is further included in the pilot valve chamber; when the pilot valve spool is in the third pilot valve position, the oil drain port for the electromagnet chamber is communicated with both the pilot valve oil return port and the pilot proportional pressure reducing outlet; when the pilot valve spool is in the fourth pilot valve position, the oil drain port for the electromagnet chamber is disconnected from both the pilot valve oil return port and the pilot proportional pressure reducing outlet.

[0013] In an embodiment of the present disclosure, the pilot valve portion further includes a pilot return spring; the pilot return spring is arranged in the pilot valve body and is configured to push the pilot valve spool to the third pilot valve position when the proportional electromagnet is powered off.

[0014] In an embodiment of the present disclosure, the main valve spool includes a blocking portion and an extending portion, and the radial dimension of the blocking portion is configured to be larger than that of the extending portion; the main valve inlet port is arranged radially outside the blocking portion; the main valve outlet port is arranged radially outside the extending portion;

[0015] When the main spool valve is in the first main valve position, a gap is formed between the second end of the blocking portion and the main valve body, so that the main valve inlet and the main valve outlet are communicated; when in the second main valve position, the second end of the blocking portion is sealed with the main valve body, so that the main valve inlet and the main valve outlet are disconnected.

[0016] In an embodiment of the present disclosure, the main valve inlet is arranged on the first side of the main spool valve, and the main valve outlet is located on the second side of the main valve inlet;

[0017] An oil guiding pipeline is arranged in the main spool valve, and the oil guiding pipeline is respectively communicated with the main valve inlet and a plunger oil outlet arranged on the second side of the main spool valve; the hydraulic oil at the main valve inlet is configured to flow through the oil guiding pipeline and flow out from the plunger oil outlet on the second side of the main spool valve to the second side of the main spool valve, so as to push the main spool valve in the direction where the first main valve position is located.

[0018] In an embodiment of the present disclosure, the oil guiding pipeline includes a radial portion extending radially and communicated with the main valve inlet and an axial portion extending axially and communicated with the plunger oil outlet.

[0019] In an embodiment of the present disclosure, the radial portion is arranged in the blocking portion, and the axial portion is arranged in the blocking portion and the extending portion.

[0020] In an embodiment of the present disclosure, it further includes a control plunger, the control plunger is arranged on the second side of the inner cavity of the main valve body and is configured to be inserted into the inside of the second end of the main spool valve, and the plunger oil outlet is arranged on the control plunger.

[0021] The present disclosure provides a pilot-operated proportional overflow valve, including:

[0022] A main valve portion, the main valve portion includes a main valve body, a main spool valve and a main valve return spring. A main valve cavity is formed in the main spool valve. A main valve inlet and a main valve outlet are respectively arranged in the main valve cavity. The main spool valve has a first main valve position and a second main valve position. When in the first main valve position, the main valve inlet and the main valve outlet are communicated. When in the second main valve position, the main valve inlet and the main valve outlet are disconnected. The main valve return spring is located in the main valve spring cavity and is configured to push the main spool valve in the direction where the second main valve position is located. The hydraulic oil at the main valve inlet is configured to push the main spool valve in the direction where the first main valve position is located;

[0023] Pilot valve section, the pilot valve section includes a pilot valve body, a pilot valve spool and a proportional electromagnet. A pilot valve cavity is formed in the pilot valve spool, and at least a pilot valve oil inlet is provided in the pilot valve cavity; the pilot valve spool has a third pilot valve position and a fourth pilot valve position, and the proportional electromagnet is configured to move the pilot valve spool between the third pilot valve position and the fourth pilot valve position; when the pilot valve spool is in the third pilot valve position, the pilot valve oil inlet is closed, and the hydraulic oil at the main valve oil inlet is configured to push the main valve spool in the direction where the first main valve position is located against the elastic force of the main valve return spring; when the pilot valve spool is in the fourth pilot valve position, the pilot valve oil inlet is opened and communicated with the main valve spring chamber through a connecting pipeline, and the hydraulic oil at the pilot valve oil inlet is configured to flow into the main valve spring chamber; the hydraulic oil at the main valve oil inlet is configured to push the main valve spool in the direction where the first main valve position is located against the elastic force of the main valve return spring and the pressure of the hydraulic oil in the main valve spring chamber.

[0024] That is, during the use of the pilot-operated proportional relief valve of the present disclosure, the proportional electromagnet can move the pilot valve spool between the third pilot valve position and the fourth pilot valve position. When the pilot valve spool is in the third pilot valve position, the pilot valve oil inlet is closed; when the hydraulic oil pressure at the main valve oil inlet is less than the elastic force of the main valve return spring, the main valve spool is in the second main valve position; when the hydraulic oil pressure at the main valve oil inlet is greater than the elastic force of the main valve return spring, the main valve spool can be pushed in the direction where the first main valve position is located, and then the main valve spool moves to the first main valve position; in this way, the main valve oil inlet and the main valve oil outlet are communicated, and the hydraulic oil at the main valve oil inlet can flow into the main valve oil outlet. Since the pilot valve spool is in the third pilot valve position, the hydraulic oil at the main valve oil inlet only needs to overcome the elastic force of the main valve return spring to push the main valve spool in the direction where the first main valve position is located, and the required pressure is small, so the main valve is in a pressure relief state.

[0025] When the pilot valve spool is in the fourth pilot valve position, the pilot valve oil inlet is opened and communicated with the main valve spring chamber through a connecting pipeline, and the hydraulic oil at the pilot valve oil inlet flows into the main valve spring chamber; when the hydraulic oil pressure at the main valve oil inlet is less than the elastic force of the main valve return spring and the pressure of the hydraulic oil in the main valve spring chamber, the main valve spool is in the second main valve position; when the hydraulic oil pressure at the main valve oil inlet is greater than the elastic force of the main valve return spring and the pressure of the hydraulic oil in the main valve spring chamber, the main valve spool can be pushed in the direction where the first main valve position is located, and then the main valve spool moves to the first main valve position, so that the main valve oil inlet and the main valve oil outlet are communicated, and the hydraulic oil at the main valve oil inlet flows into the main valve oil outlet. Since the pilot valve spool is in the fourth pilot valve position, the hydraulic oil at the main valve oil inlet needs to overcome the elastic force of the main valve return spring and the pressure of the hydraulic oil in the main valve spring chamber to push the main valve spool in the direction where the first main valve position is located, and the required pressure is small, so the main valve is in a pressure boosting state.

[0026] Therefore, the pilot-operated proportional relief valve of the present disclosure, through the structural design of integrating the pilot valve and the main valve, can control the position of the pilot valve core by using a proportional electromagnet and then amplify it through the main valve, so as to effectively control the pressure at the main valve inlet port, with convenient operation and fast response speed. Moreover, both the pilot valve core and the main valve core adopt a spool valve structure, and the leakage performance and pressure regulation performance are relatively stable. Compared with the relief valves used in existing hydraulic transmission systems, the control part of the pilot-operated proportional relief valve of the present disclosure has a simple structure, is easy to operate, is not prone to failure, and is simple to repair.

[0027] Other features and advantages of the present disclosure will become clear from the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] 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.

[0029] Figure 1 is a cross-sectional schematic view of the pilot-operated proportional relief valve provided by an embodiment of the present disclosure when the main valve is in the first main valve position;

[0030] Figure 2 is a cross-sectional schematic view of the pilot-operated proportional relief valve provided by an embodiment of the present disclosure when the main valve is in the second main valve position;

[0031] Figures 1 to 2 The corresponding relationships between the names of the components and the reference numerals in are as follows:

[0032] 10. Main valve part; 11. Main valve body; 111. Control plunger; 112. Plunger oil outlet hole; 12. Main valve core; 121. Blocking part; 122. Extension part; 123. Oil guiding pipeline; 1231. Axial part; 1232. Radial part; 13. Main valve return spring; 14. Main valve cavity; 141. Main valve inlet port; 142. Main valve outlet port; 143. Main valve spring cavity; 20. Pilot valve part; 21. Pilot valve body; 22. Pilot valve core; 23. Proportional electromagnet; 24. Pilot valve cavity; 241. Pilot valve inlet port; 242. Pilot valve return port; 243. Pilot proportional pressure reduction outlet; 244. Electromagnet cavity oil drain port; 25. Pilot return spring; 30. Connecting pipeline. A: First side; B: Second side. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] 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 arrangements of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present disclosure. In all the examples shown and discussed herein, any specific value should be construed as merely exemplary, and not as a limitation. Thus, other examples of the exemplary embodiments may have different values.

[0034] Numerous specific details are set forth in the following description in order to provide a thorough understanding of the present disclosure. However, the present disclosure can be implemented in many other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the spirit of the present disclosure. Therefore, the present disclosure is not limited by the specific embodiments disclosed below. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the specification.

[0035] 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 "said" used in one or more embodiments of the present disclosure and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" used in one or more embodiments of the present disclosure refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0036] It should be understood that although the terms first, second, etc. may be used in one or more embodiments of the present disclosure to describe various information, 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 "when" or "while" or "in response to determining". In this document, "above", "below", "front", "rear", "left", "right", etc. are only used to represent the relative positional relationship between relevant parts, rather than to limit the absolute positions of these relevant parts. In this document, "equal", "same", etc. are not strict mathematical and / or geometric limitations, and also include errors that can be understood by those skilled in the art and are allowed in manufacturing or using, etc. Unless otherwise specified, the numerical ranges herein include not only the entire range between its two endpoints, but also several sub-ranges subsumed therein.

[0037] The present disclosure provides a pilot-operated proportional overflow valve, comprising:

[0038] Main valve section, the main valve section includes a main valve body, a main valve spool and a main valve return spring. A main valve cavity is formed in the main valve spool. A main valve oil inlet and a main valve oil outlet are respectively arranged in the main valve cavity. The main valve spool has a first main valve position and a second main valve position. When in the first main valve position, the main valve oil inlet and the main valve oil outlet are communicated. When in the second main valve position, the main valve oil inlet and the main valve oil outlet are disconnected. The main valve return spring is located in the main valve spring cavity and is configured to push the main valve spool in the direction of the second main valve position. The hydraulic oil at the main valve oil inlet is configured to push the main valve spool in the direction of the first main valve position.

[0039] Pilot valve section, the pilot valve section includes a pilot valve body, a pilot valve spool and a proportional electromagnet. A pilot valve cavity is formed in the pilot valve spool. At least a pilot valve oil inlet is arranged in the pilot valve cavity. The pilot valve spool has a third pilot valve position and a fourth pilot valve position. The proportional electromagnet is configured to move the pilot valve spool between the third pilot valve position and the fourth pilot valve position. When the pilot valve spool is in the third pilot valve position, the pilot valve oil inlet is closed. The hydraulic oil at the main valve oil inlet is configured to push the main valve spool in the direction of the first main valve position against the elastic force of the main valve return spring. When the pilot valve spool is in the fourth pilot valve position, the pilot valve oil inlet is opened and is communicated with the main valve spring cavity through a connecting pipeline. The hydraulic oil at the pilot valve oil inlet is configured to flow into the main valve spring cavity. The hydraulic oil at the main valve oil inlet is configured to push the main valve spool in the direction of the first main valve position against the elastic force of the main valve return spring and the pressure of the hydraulic oil in the main valve spring cavity.

[0040] That is, during the use of the pilot-operated proportional relief valve of the present disclosure, the proportional electromagnet can move the pilot valve spool between the third pilot valve position and the fourth pilot valve position. When the pilot valve spool is in the third pilot valve position, the pilot valve oil inlet is closed. When the hydraulic oil pressure at the main valve oil inlet is less than the elastic force of the main valve return spring, the main valve spool is in the second main valve position. When the hydraulic oil pressure at the main valve oil inlet is greater than the elastic force of the main valve return spring, the main valve spool can be pushed in the direction of the first main valve position, and then the main valve spool moves to the first main valve position. In this way, the main valve oil inlet and the main valve oil outlet are communicated, and the hydraulic oil at the main valve oil inlet can flow into the main valve oil outlet. Since the pilot valve spool is in the third pilot valve position, the hydraulic oil at the main valve oil inlet only needs to overcome the elastic force of the main valve return spring to push the main valve spool in the direction of the first main valve position, and the required pressure is small. Therefore, the main valve is in a pressure relief state.

[0041] When the pilot valve spool is in the fourth pilot valve position, the pilot valve inlet port is opened and communicated with the main valve spring chamber through a connecting pipeline, and the hydraulic oil at the pilot valve inlet port flows to the main valve spring chamber; when the hydraulic oil pressure at the main valve inlet port is less than the elastic force of the main valve return spring and the hydraulic oil pressure in the main valve spring chamber, the main valve spool is in the second main valve position; when the hydraulic oil pressure at the main valve inlet port is greater than the elastic force of the main valve return spring and the hydraulic oil pressure in the main valve spring chamber, the main valve spool can be pushed in the direction of the first main valve position, and then the main valve spool moves to the first main valve position, so that the main valve inlet port and the main valve outlet port are communicated, and the hydraulic oil at the main valve inlet port flows into the main valve outlet port. Since the pilot valve spool is in the fourth pilot valve position, the hydraulic oil at the main valve inlet port needs to overcome the elastic force of the main valve return spring and the hydraulic oil pressure in the main valve spring chamber to push the main valve spool in the direction of the first main valve position, and the required pressure is relatively small, so the main valve is in a pressure boosting state.

[0042] Therefore, through the integrated structural design of the pilot valve and the main valve of the pilot-operated proportional overflow valve disclosed in the present disclosure, the position of the pilot valve spool can be controlled by using a proportional electromagnet, and then amplified by the main valve, so that the pressure at the main valve inlet port can be effectively controlled, with convenient operation and fast response speed. Moreover, both the pilot valve spool and the main valve spool adopt a spool structure, and the leakage performance and pressure regulating performance are relatively stable. Compared with the overflow valve used in the existing hydraulic transmission system, the control part of the pilot-operated proportional overflow valve disclosed in the present disclosure has a simple structure, is easy to operate, is not prone to failure, and is simple to repair.

[0043] For the sake of easy understanding, hereinafter, with reference to Figures 1 to 2 and in conjunction with an embodiment, the specific structure and working principle of the pilot-operated proportional overflow valve disclosed in the present disclosure will be described in detail.

[0044] As Figure 1 and Figure 2 shown, the present disclosure provides a pilot-operated proportional overflow valve, including:

[0045] The main valve part 10, the main valve part 10 includes a main valve body 11, a main valve spool 12 and a main valve return spring 13. A main valve chamber 14 is formed in the main valve spool 12. A main valve inlet port 141 and a main valve outlet port 142 are respectively arranged in the main valve chamber 14. The main valve spool 12 has a first main valve position and a second main valve position. As Figure 1 shown, when in the first main valve position, the main valve inlet port 141 and the main valve outlet port 142 are communicated. As Figure 2 shown, when in the second main valve position, the main valve inlet port 141 and the main valve outlet port 142 are disconnected. The main valve return spring 13 is located in the main valve spring chamber 143 and is configured to push the main valve spool 12 in the direction of the second main valve position. The hydraulic oil at the main valve inlet port 141 is configured to push the main valve spool 12 in the direction of the first main valve position;

[0046] The pilot valve section 20, the pilot valve section 20 includes a pilot valve body 21, a pilot valve spool 22 and a proportional solenoid 23. A pilot valve chamber 24 is formed in the pilot valve spool 22, and at least a pilot valve inlet 241 is provided in the pilot valve chamber 24;

[0047] The pilot valve spool 22 has a third pilot valve position and a fourth pilot valve position, and the proportional solenoid 23 is configured to move the pilot valve spool 22 between the third pilot valve position and the fourth pilot valve position;

[0048] When the pilot valve spool 22 is in the third pilot valve position, the pilot valve inlet 241 is closed, and the hydraulic oil at the main valve inlet 141 is configured to push the main valve spool 12 in the direction of the first main valve position against the elastic force of the main valve return spring 13;

[0049] When the pilot valve spool 22 is in the fourth pilot valve position, the pilot valve inlet 241 is opened and communicated with the main valve spring chamber 143 through a connecting pipeline 30, and the hydraulic oil at the pilot valve inlet 241 is configured to flow into the main valve spring chamber 143; the hydraulic oil at the main valve inlet 141 is configured to push the main valve spool 12 in the direction of the first main valve position against the elastic force of the main valve return spring 13 and the pressure of the hydraulic oil in the main valve spring chamber 143;

[0050] That is, during the use of the pilot-operated proportional relief valve of the present disclosure, the proportional solenoid 23 can move the pilot valve spool 22 between the third pilot valve position and the fourth pilot valve position. When the pilot valve spool 22 is in the third pilot valve position, the pilot valve inlet 241 is closed; when the hydraulic oil pressure at the main valve inlet 141 is less than the elastic force of the main valve return spring 13, the main valve spool 12 is in the second main valve position; when the hydraulic oil pressure at the main valve inlet 141 is greater than the elastic force of the main valve return spring 13, the main valve spool 12 can be pushed in the direction of the first main valve position, and then the main valve spool 12 moves to the first main valve position; in this way, the main valve inlet 141 and the main valve outlet 142 are communicated, and the hydraulic oil at the main valve inlet 141 can flow into the main valve outlet 142. Since the pilot valve spool 22 is in the third pilot valve position, the hydraulic oil at the main valve inlet 141 only needs to overcome the elastic force of the main valve return spring 13 to push the main valve spool 12 in the direction of the first main valve position, and the required pressure is small, so the main valve is in a pressure relief state.

[0051] When the pilot valve spool 22 is in the fourth pilot valve position, the pilot valve inlet 241 is opened and communicated with the main valve spring chamber 143 through the communication pipeline 30, and the hydraulic oil at the pilot valve inlet 241 flows to the main valve spring chamber 143; when the hydraulic oil pressure at the main valve inlet 141 is less than the elastic force of the main valve return spring 13 and the hydraulic oil pressure in the main valve spring chamber 143, the main valve spool 12 is in the second main valve position; when the hydraulic oil pressure at the main valve inlet 141 is greater than the elastic force of the main valve return spring 13 and the hydraulic oil pressure in the main valve spring chamber 143, the main valve spool 12 can be pushed in the direction where the first main valve position is located, and then the main valve spool 12 moves to the first main valve position, so that the main valve inlet 141 and the main valve outlet 142 are communicated, and the hydraulic oil at the main valve inlet 141 flows into the main valve outlet 142. Since the pilot valve spool 22 is in the fourth pilot valve position, the hydraulic oil at the main valve inlet 141 needs to overcome the elastic force of the main valve return spring 13 and the hydraulic oil pressure in the main valve spring chamber 143 to push the main valve spool 12 in the direction where the first main valve position is located, and the required pressure is relatively small. Therefore, the main valve is in a pressure boosting state.

[0052] Therefore, through the integrated structural design of the pilot valve and the main valve of the pilot-operated proportional overflow valve disclosed in the present disclosure, the position of the pilot valve spool 22 can be controlled by using the proportional electromagnet 23, and then amplified by the main valve, so that the pressure at the main valve inlet 141 can be effectively controlled, with convenient operation and fast response speed. And both the pilot valve spool 22 and the main valve spool 12 adopt a spool structure, and the leakage performance and pressure regulating performance are relatively stable. Compared with the overflow valve used in the existing hydraulic transmission system, the control part of the pilot-operated proportional overflow valve disclosed in the present disclosure has a simple structure, is convenient to operate, is not prone to failure, and is simple to repair. Specifically, the pilot-operated proportional overflow valve disclosed in the present disclosure can be applied to the maintenance equipment in the high-speed rail industry for remotely controlling the traction and braking pressures of vehicles steplessly.

[0053] It can be understood that the main valve body 11 and the pilot valve body 21 are only divided for different functions, and they can be an integral structure or a split structure, which is not limited herein.

[0054] Such as Figure 1 and Figure 2 As shown, in an embodiment of the present disclosure, a pilot valve oil return port 242 is further provided in the pilot valve chamber 24; when the pilot valve spool 22 is in the third pilot valve position, the pilot valve oil return port 242 is communicated with the main valve spring chamber 143 through the communication pipeline 30, and the hydraulic oil in the main valve spring chamber 143 is configured to at least partially flow to the pilot valve oil return port 242; when the pilot valve spool 22 is in the fourth pilot valve position, the pilot valve oil return port 242 is disconnected from the communication pipeline 30.

[0055] Thus, during the use of the pilot-operated proportional overflow valve of the present disclosure, when the pilot spool 22 is in the third pilot valve position, the pilot valve oil return port 242 communicates with the main valve spring chamber 143 through the connecting pipeline 30. At least part of the hydraulic oil in the main valve spring chamber 143 can flow to the pilot valve oil return port 242 through the connecting pipeline 30, thereby effectively realizing the oil return in the main valve spring chamber 143. When the pilot spool 22 is in the fourth pilot valve position, the pilot valve oil return port 242 is disconnected from the connecting pipeline 30, thereby cutting off the oil return in the main valve spring chamber 143 and ensuring that the hydraulic oil in the main valve spring chamber 143 can provide pressure to the main spool 12 to increase the pressure at the main valve oil inlet 141 and achieve the purpose of pressure boosting.

[0056] As Figure 1 and Figure 2 shown, in an embodiment of the present disclosure, the pilot valve portion 20 further includes a pilot return spring 25; the pilot return spring 25 is disposed in the pilot valve body 21 and is configured to push the pilot spool 22 to the third pilot valve position when the proportional electromagnet 23 is de-energized. By arranging the pilot return spring 25 in the pilot valve body 21, it can effectively ensure that the pilot spool 22 can return to the third pilot valve position when the proportional electromagnet 23 is de-energized, ensuring that the main valve is in a pressure relief state.

[0057] As Figure 1 and Figure 2 shown, in an embodiment of the present disclosure, a pilot proportional pressure reducing outlet 243 is further provided in the pilot valve chamber 24; when the pilot spool 22 is in the third pilot valve position, the pilot valve oil return port 242 communicates with the pilot proportional pressure reducing outlet 243; when the pilot spool 22 is in the fourth pilot valve position, the pilot valve oil inlet 241 communicates with the pilot proportional pressure reducing outlet 243, the pilot valve oil inlet 241 is opened, and communicates with the main valve spring chamber 143 through the pilot proportional pressure reducing outlet 243 and the connecting pipeline 30. The hydraulic oil at the pilot valve oil inlet 241 is configured to flow to the main valve spring chamber 143; the proportional electromagnet 23 is configured to control the opening degree of the pilot proportional pressure reducing outlet 243 based on the input current.

[0058] It can be seen that since the opening degree of the pilot proportional pressure reducing outlet 243 is dynamically matched with the thrust provided by the proportional electromagnet 23 to the pilot spool 22 and the elastic force of the pilot return spring 25, a function similar to that of a pressure reducing valve is formed, effectively achieving the purpose of dynamically and steplessly controlling the opening degree of the pilot proportional pressure reducing outlet 243.

[0059] During the use of the pilot-operated proportional overflow valve of the present disclosure, the proportional electromagnet 23 can move the pilot spool 22 between the third pilot valve position and the fourth pilot valve position based on the input current and control the opening degree of the pilot proportional pressure reducing outlet 243.

[0060] By controlling the opening degree of the pilot proportional pressure reducing outlet 243, the pressure of the hydraulic oil at the pilot valve inlet 241 can be controlled, and further the pressure of the hydraulic oil flowing into the main valve spring chamber 143 can be controlled. Since the pressure of the hydraulic oil at the main valve inlet 141 is greater than the elastic force of the main valve return spring 13 and the pressure of the hydraulic oil in the main valve spring chamber 143, the main valve core 12 can be pushed in the direction of the first main valve position, and then the main valve core 12 moves to the first main valve position, so that the main valve inlet 141 and the main valve outlet 142 are communicated, and the hydraulic oil at the main valve inlet 141 flows into the main valve outlet 142.

[0061] Therefore, the pilot-operated proportional relief valve of the present disclosure can control the opening degree of the pilot proportional pressure reducing outlet 243 by controlling the magnitude of the input current of the proportional solenoid 23, thereby controlling the opening pressure of the main valve core 12, that is, the pressure at the main valve inlet 141, so as to ensure that the pressure at the main valve inlet 141 can be maintained at the corresponding value of the input current of the proportional solenoid 23, achieving the purpose of proportional pressure regulation.

[0062] Through the above principle of proportional pressure regulation, the problem that the minimum pressure is not easy to accurately control is effectively solved. In practical applications, the pilot-operated proportional relief valve of the present disclosure can achieve accurate control in the range of 0.3 to 2.1 MPa at a flow rate of 100 L / min, well meeting the control performance requirements.

[0063] Compared with the existing proportional relief valve, the pilot-operated proportional relief valve of the present disclosure has a rapid response and reliable closing; using the proportional solenoid 23 for stepless control, stepless adjustment of the pressure at the main valve inlet 141 can be achieved, and it has good dynamic performance, fast response speed, small hysteresis, and high repeatability accuracy.

[0064] In order to increase the available ambient temperature range, the proportional solenoid 23 and other components of the pilot-operated proportional relief valve of the present disclosure can use high and low temperature resistant materials to ensure reliable operation in the extreme environment of -40°C to 150°C.

[0065] Such as Figure 1 and Figure 2 As shown, in an embodiment of the present disclosure, the pilot valve chamber 24 further includes an electromagnetic solenoid chamber oil drain port 244; when the pilot valve core 22 is in the third pilot valve position, the electromagnetic solenoid chamber oil drain port 244 is communicated with both the pilot valve oil return port 242 and the pilot proportional pressure reducing outlet 243; when the pilot valve core 22 is in the fourth pilot valve position, the electromagnetic solenoid chamber oil drain port 244 is disconnected from both the pilot valve oil return port 242 and the pilot proportional pressure reducing outlet 243.

[0066] During the use of the pilot-operated proportional relief valve of the present disclosure, when the pilot spool 22 is in the third pilot valve position, the oil drain port 244 of the electromagnet chamber is communicated with the pilot valve oil return port 242 and the pilot proportional pressure reducing outlet 243, so that the oil drain of the electromagnet chamber can be effectively realized; the oil drain port 244 of the electromagnet chamber is disconnected from the pilot valve oil return port 242 and the pilot proportional pressure reducing outlet 243, so as to ensure that the hydraulic oil at the pilot valve oil inlet 241 flows through the pilot proportional pressure reducing outlet 243 and the connecting pipeline 30 to the main valve spring chamber 143.

[0067] As Figure 1 and Figure 2 shown, in an embodiment of the present disclosure, the main spool 12 includes a plugging portion 121 and an extending portion 122. The plugging portion 121 is configured to have a radial dimension larger than that of the extending portion 122; the main valve oil inlet 141 is disposed radially outside the plugging portion 121; the main valve oil outlet 142 is disposed radially outside the extending portion 122; when the main spool 12 is in the first main valve position, a gap is formed between the second end of the plugging portion 121 and the main valve body 11, so that the main valve oil inlet 141 and the main valve oil outlet 142 are communicated; when in the second main valve position, the second end of the plugging portion 121 is sealed with the main valve body 11, so that the main valve oil inlet 141 and the main valve oil outlet 142 are disconnected.

[0068] That is, during the working process of the pilot-operated proportional relief valve of the present disclosure, when the main spool 12 is in the first main valve position, a gap is formed between the second end of the plugging portion 121 and the main valve body 11, and the main valve oil inlet 141 and the main valve oil outlet 142 are communicated, and the hydraulic oil at the main valve oil inlet 141 can flow into the main valve oil outlet 142; when the main spool 12 is in the second main valve position, the second end of the plugging portion 121 is sealed with the main valve body 11, so that the main valve oil inlet 141 and the main valve oil outlet 142 are disconnected. Since the radial dimension of the plugging portion 121 is larger than that of the extending portion 122; the main valve oil inlet 141 is disposed radially outside the plugging portion 121, and the main valve oil outlet 142 is disposed radially outside the extending portion 122, it is convenient to switch the state between the communication and disconnection between the main valve oil inlet 141 and the main valve oil outlet 142 by moving the position of the plugging portion 121.

[0069] Further, as Figure 1 and Figure 2As shown, in an embodiment of the present disclosure, the main valve inlet 141 is provided on the first side of the main valve spool 12, and the main valve outlet 142 is located on the second side of the main valve inlet 141; a oil guiding pipeline 123 is arranged inside the main valve spool 12, and the oil guiding pipeline 123 is respectively communicated with the main valve inlet 141 and the plunger oil outlet hole 112 provided on the second side of the main valve spool 12; the hydraulic oil at the main valve inlet 141 is configured to flow through the oil guiding pipeline 123 and flow out from the plunger oil outlet hole 112 on the second side of the main valve spool 12 to the second side of the main valve spool 12, so as to push the main valve spool 12 in the direction where the first main valve position is located. By arranging the oil guiding pipeline 123 inside the main valve spool 12, it is convenient for the hydraulic oil at the main valve outlet 142 to flow to the plunger oil outlet hole 112 on the second side of the main valve spool 12 and flow out from the plunger oil outlet hole 112, thereby applying pressure to the second side of the main valve spool 12.

[0070] As Figure 1 and Figure 2 As shown, in an embodiment of the present disclosure, the oil guiding pipeline 123 includes a radial portion 1232 extending radially and communicated with the main valve inlet 141 and an axial portion 1231 extending axially and communicated with the plunger oil outlet hole 112. Since the oil guiding pipeline 123 includes a radial portion 1232 extending radially and communicated with the main valve inlet 141 and an axial portion 1231 extending axially and communicated with the plunger oil outlet hole 112, the hydraulic oil at the main valve outlet 142 can first flow radially into the radial portion 1232 of the oil guiding pipeline 123, and then flow along the axial portion 1231 of the oil guiding pipeline 123 to the plunger oil outlet hole 112 on the second side of the main valve spool 12 and flow out from the plunger oil outlet hole 112.

[0071] As Figure 1 and Figure 2 As shown, in an embodiment of the present disclosure, the radial portion 1232 is arranged inside the blocking portion 121, and the axial portion 1231 is arranged inside the blocking portion 121 and the extending portion 122. In this way, it is convenient for the axial portion 1231 to be arranged on the axis of the main valve spool 12, and it is also convenient for the radial portion 1232 to be respectively communicated with the main valve outlet 142 and the axial portion 1231.

[0072] As Figure 1 and Figure 2 As shown, in an embodiment of the present disclosure, the pilot-operated proportional relief valve of the present disclosure further includes a control plunger 111, the control plunger 111 is arranged on the second side of the inner cavity of the main valve body 11, and is configured to be inserted inside the second end of the main valve spool 12, and the plunger oil outlet hole 112 is arranged on the control plunger 111.

[0073] Since the control plunger 111 is disposed on the second side of the inner cavity of the main valve body 11 and inserted into the second end of the main spool 12, and the plunger oil outlet hole 112 is provided on the control plunger 111, it can be ensured that regardless of whether the main spool 12 is in the first main valve position or the second main valve position, the hydraulic oil at the main valve oil outlet 142 can flow from the oil guiding pipeline 123 into the control plunger 111 and flow out from the plunger oil outlet hole 112 on the control plunger 111, so as to apply pressure to the second side of the main spool 12.

[0074] The embodiments of the present disclosure have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to technologies in the market, or to enable other ordinary skill in the art in the technical field to understand the disclosed embodiments. The scope of the present disclosure is defined by the appended claims.

Claims

1. A pilot-operated proportional relief valve, characterized in that: include: A main valve portion (10), the main valve portion (10) comprising a main valve body (11), a main valve core (12) and a main valve return spring (13), a main valve cavity (14) being formed in the main valve core (12), a main valve oil inlet (141) and a main valve oil outlet (142) being respectively arranged in the main valve cavity (14), the main valve core (12) having a first main valve position and a second main valve position, in the first main valve position, the main valve oil inlet (141) and the main valve oil outlet (142) being arranged in the main valve core (12) 1) is connected to the main valve oil outlet (142), when in the second main valve position, the main valve oil inlet (141) and the main valve oil outlet (142) are disconnected, the main valve return spring (13) is located in the main valve spring chamber (143), and is configured to push the main valve core (12) in the direction of the second main valve position, and the hydraulic oil in the main valve oil inlet (141) is configured to push the main valve core (12) in the direction of the first main valve position; 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), the pilot valve core (22) forming a pilot valve cavity (24), the pilot valve cavity (24) being provided with at least a pilot valve oil inlet (241); the pilot valve core (22) having a third pilot valve position and a fourth pilot valve position, the proportional solenoid (23) being configured to move the pilot valve core (22) between the third pilot valve position and the fourth pilot valve position; The pilot valve core (22) is in the third pilot valve position, the pilot valve oil inlet (241) is closed, and the hydraulic oil in the main valve oil inlet (141) is configured to overcome the elastic force of the main valve return spring (13) and push the main valve core (12) in the direction of the first main valve position; When the pilot valve core (22) is in the fourth pilot valve position, the pilot valve oil inlet (241) is opened and connected to the main valve spring chamber (143) through the connecting pipeline (30), and the hydraulic oil in the pilot valve oil inlet (241) is constructed to flow to the main valve spring chamber (143); the hydraulic oil in the main valve oil inlet (141) is constructed to overcome the elastic force of the main valve return spring (13) and the pressure of the hydraulic oil in the main valve spring chamber (143) to push the main valve core (12) in the direction of the first main valve position.

2. The pilot-operated proportional relief valve according to claim 1, characterized in that: A pilot valve oil return port (242) is also provided in the pilot valve chamber (24); When the pilot valve core (22) is in the third pilot valve position, the pilot valve oil return port (242) is connected to the main valve spring chamber (143) through the connecting pipeline (30), and the hydraulic oil in the main valve spring chamber (143) is configured to at least partially flow to the pilot valve oil return port (242); when the pilot valve core (22) is in the fourth pilot valve position, the pilot valve oil return port (242) is disconnected from the connecting pipeline (30).

3. The pilot-operated proportional relief valve according to claim 2, characterized in that: A pilot proportional pressure reducing outlet (243) is also provided in the pilot valve chamber (24); When the pilot valve core (22) is in the third pilot valve position, the pilot valve oil return port (242) is in communication with the pilot proportional pressure reducing outlet (243); when the pilot valve core (22) is in the fourth pilot valve position, the pilot valve oil inlet (241) is in communication with the pilot proportional pressure reducing outlet (243), the pilot valve oil inlet (241) is opened, and is in communication with the main valve spring chamber (143) through the pilot proportional pressure reducing outlet (243) and the connecting pipeline (30), and the hydraulic oil in the pilot valve oil inlet (241) is configured to flow into the main valve spring chamber (143); The proportional solenoid (23) is configured to control the opening of the pilot proportional pressure reducing outlet (243) based on an input current.

4. The pilot-operated proportional relief valve according to claim 3, characterized in that: The pilot valve cavity (24) also includes an electromagnet cavity oil drain port (244); when the pilot valve core (22) is in the third pilot valve position, the electromagnet cavity oil drain port (244) is connected to the pilot valve oil return port (242) and the pilot proportional pressure reducing outlet (243); when the pilot valve core (22) is in the fourth pilot valve position, the electromagnet cavity oil drain port (244) is disconnected from the pilot valve oil return port (242) and the pilot proportional pressure reducing outlet (243).

5. The pilot-operated proportional relief valve according to claim 4, characterized in that: The pilot valve portion (20) further comprises a pilot return spring (25); the pilot return spring (25) is arranged in the pilot valve body (21) and is configured to push the pilot valve core (22) to a third pilot valve position when the proportional solenoid (23) is powered off.

6. The pilot-operated proportional relief valve according to any one of claims 1 to 5, characterized in that: The main valve core (12) comprises a blocking portion (121) and an extending portion (122); the blocking portion (121) is configured to have a radial dimension larger than that of the extending portion (122); the main valve oil inlet (141) is arranged radially outside the blocking portion (121); and the main valve oil outlet (142) is arranged radially outside the extending portion (122); When the main valve core (12) is in the first main valve position, a gap is formed between the second end of the sealing portion (121) and the main valve body (11), so that the main valve oil inlet (141) and the main valve oil outlet (142) are connected; when it is in the second main valve position, the second end of the sealing portion (121) is sealed with the main valve body (11), so that the main valve oil inlet (141) and the main valve oil outlet (142) are disconnected.

7. The pilot-operated proportional relief valve according to claim 6, characterized in that: The main valve oil inlet (141) is arranged on a first side of the main valve core (12), and the main valve oil outlet (142) is located on a second side of the main valve oil inlet (141); An oil guide pipeline (123) is provided in the main valve core (12), and the oil guide pipeline (123) is respectively connected to the main valve oil inlet (141) and the plunger oil outlet hole (112) provided on the second side of the main valve core (12); the hydraulic oil in the main valve oil inlet (141) is constructed to flow through the oil guide pipeline (123), and flow out from the plunger oil outlet hole (112) on the second side of the main valve core (12) to the second side of the main valve core (12), so as to push the main valve core (12) in the direction of the first main valve position.

8. The pilot-operated proportional relief valve according to claim 7, characterized in that: The oil guide pipeline (123) comprises a radial portion (1232) extending in the radial direction and communicating with the main valve oil inlet (141), and an axial portion (1231) extending in the axial direction and communicating with the plunger oil outlet hole (112).

9. The pilot-operated proportional relief valve according to claim 8, characterized in that: The radial portion (1232) is disposed in the blocking portion (121), and the axial portion (1231) is disposed in the blocking portion (121) and the extending portion (122).

10. The pilot-operated proportional relief valve according to claim 7, characterized in that: It also includes a control plunger (111), which is arranged on the second side of the inner cavity of the main valve body (11) and is configured to be inserted into the second end of the main valve core (12), and the plunger oil outlet hole (112) is arranged on the control plunger (111).

Images