Proportional valve for pump

Abstract

The embodiment of the specification discloses a proportional valve for a pump. The proportional valve comprises a valve body, an electromagnetic proportional direction valve and a proportional overflow valve, the electromagnetic proportional direction valve is connected with the proportional overflow valve through the valve body; the valve body comprises a first cavity and a second cavity. The electromagnetic proportional direction valve is positioned in the first chamber; the proportional overflow valve is positioned in the second chamber; an oil inlet of the valve body is communicated with a first opening, used for feeding oil, of the proportional overflow valve; a second opening, used for discharging oil, of the proportional overflow valve is communicated with a first opening, used for feeding oil, of the electromagnetic proportional direction valve; a second opening, used for discharging oil, of the electromagnetic proportional direction valve is communicated with the oil outlet of the valve body; and a third opening, used for discharging oil, of the proportional overflow valve is communicated with the unloading opening of the valve body. The electromagnetic proportional direction valve and the proportional overflow valve are connected through the valve body, the occupied space of the proportional valve is reduced, and meanwhile the proportional valve has the functions of pressure control and direction control at the same time.

Description

Technical Field

[0001] The present application relates to the technical field of proportional valves, and in particular to a proportional valve for a pump. Background Art

[0002] Valves are widely used in various fields, such as mining, transportation, drilling, and daily life. However, most existing valves are proportional directional valves used to control the direction of liquids or proportional relief valves used to control the pressure of liquids, which have a single control function. In some application scenarios, when valves are needed to control the pressure and direction of liquids, proportional directional valves and pressure valves are usually combined to form a valve group. However, a valve group consisting of two valves takes up a lot of space and has the disadvantage of being difficult to assemble and disassemble.

[0003] Therefore, it is urgent to provide a proportional valve for a pump that is small in size, easy to assemble and disassemble, and has both directional control and pressure control. Summary of the Invention

[0004] The embodiments of this specification provide a proportional valve for a pump to solve the problems of single function and large size in existing proportional valves.

[0005] To solve the above technical problems, the present invention provides a proportional valve for a pump, comprising:

[0006] Valve body, electromagnetic proportional directional valve and proportional relief valve; the electromagnetic proportional directional valve and the proportional relief valve are connected through the valve body;

[0007] The valve body includes a first chamber and a second chamber; the electromagnetic proportional directional valve is located in the first chamber; the proportional relief valve is located in the second chamber;

[0008] The oil inlet of the valve body is communicated with the first opening of the proportional relief valve for oil inlet; the second opening of the proportional relief valve for oil outlet is communicated with the first opening of the electromagnetic proportional directional valve for oil inlet; the second opening of the electromagnetic proportional directional valve for oil outlet is communicated with the oil outlet of the valve body; the third opening of the proportional relief valve for oil outlet is communicated with the unloading port of the valve body.

[0009] Optionally, the valve body further includes a first oil circuit; the first oil circuit includes a first external oil circuit, a first internal oil circuit, a second external oil circuit, a second internal oil circuit and a third external oil circuit;

[0010] The oil inlet of the valve body is connected to the first opening of the proportional relief valve through the first external oil circuit; the first opening of the proportional relief valve is connected to the second opening of the proportional relief valve through the first internal oil circuit; the second opening of the proportional relief valve is connected to the first opening of the electromagnetic proportional directional valve through the second external oil circuit; the first opening of the electromagnetic proportional directional valve is connected to the second opening of the electromagnetic proportional directional valve through the second internal oil circuit; the second opening of the electromagnetic directional proportional valve is connected to the oil outlet of the valve body through the third external oil circuit.

[0011] Optionally, the valve body also includes an oil return circuit; the oil return circuit includes a fourth external oil circuit, a third internal oil circuit and a fifth external oil circuit; the oil outlet of the valve body is connected to the fourth opening of the proportional overflow valve through the fourth external oil circuit; the fourth opening of the proportional overflow valve is connected to the third opening of the proportional overflow valve through the third internal oil circuit; the third opening of the proportional overflow valve is connected to the unloading port of the valve body through the fifth external oil circuit.

[0012] Optionally, the valve body further includes a second oil circuit; the second oil circuit includes a first external oil circuit, the fourth internal oil circuit and the fourth external oil circuit;

[0013] The oil inlet of the valve body is connected to the first opening of the proportional relief valve through the first external oil circuit; the first opening of the proportional relief valve is connected to the fourth opening of the proportional relief valve through the fourth internal oil circuit; the fourth opening of the proportional relief valve is connected to the oil outlet of the valve body through the fourth external oil circuit.

[0014] Optionally, the electromagnetic proportional directional valve includes a flange and a first sealing ring; the flange is used to connect the electromagnetic proportional directional valve and the valve body; and the first sealing ring is located between the flange and the valve body.

[0015] Optionally, the electromagnetic proportional directional valve further includes a proportional solenoid and a servo valve core;

[0016] The proportional electromagnet is used to push the servo valve core to move leftward; the servo valve core is used to control the on-off of the internal oil circuit of the electromagnetic proportional directional valve.

[0017] Optionally, the electromagnetic proportional directional valve further includes a first sealing nut, a tapered end set screw, a valve seat and a first pressure spring;

[0018] The first sealing nut is used to fix the tapered end set screw; the tapered end set screw is used to adjust the position of the valve seat; the valve seat is used to control the compression degree of the first pressure spring; the first pressure spring is used to adjust the initial position of the servo valve core.

[0019] Optionally, the proportional relief valve further includes a plug screw and a second sealing ring; the plug screw is used to connect the proportional relief valve and the valve body; and the second sealing ring is located between the plug screw and the valve body.

[0020] Optionally, the proportional relief valve further comprises a screw plug, a pressure valve core, a second sealing nut, a cylindrical end set screw and a second pressure spring; the screw plug is used to connect the proportional relief valve and the valve body;

[0021] The second sealing nut is used to fix the cylindrical end set screw; the cylindrical end set screw is used to control the compression degree of the second pressure spring; the second pressure spring is used to control the position of the pressure valve core; the pressure valve core is used to control the on-off of the internal oil circuit of the proportional relief valve.

[0022] Optionally, a hexagonal wrench is used to adjust the position of the cylindrical end set screw.

[0023] At least one embodiment in this specification can achieve the following beneficial effects: This application places the electromagnetic proportional directional valve and the proportional overflow valve in the same valve body, and connects the electromagnetic proportional directional valve and the proportional overflow valve based on the oil circuit in the valve body, so that the liquid can flow between the electromagnetic proportional directional valve and the proportional overflow valve, thereby realizing pressure control and direction control, and also reducing the space occupied by the proportional valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] To more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some of the embodiments described in this application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0025] Figure 1 This is a schematic cross-sectional view of a proportional valve for a pump provided in an embodiment of this specification;

[0026] Figure 2 This is a front view of a proportional valve for a pump provided in an embodiment of this specification;

[0027] Figure 3 This is a hydraulic control principle diagram of a proportional valve for a pump provided in an embodiment of this specification.

[0028] Reference numerals:

[0029] 1. Proportional relief valve; 10. Pressure valve core; 11. Spring seat; 12. Screw plug; 13. Second sealing nut; 14. Cylindrical end set screw; 15. Second pressure spring; 16. Second sealing ring; 101. First opening of the proportional relief valve; 102. Second opening of the proportional relief valve.

[0030] 2. Solenoid proportional directional valve; 20. Flange; 21. Proportional solenoid; 22. First sealing ring; 23. Cone-end set screw; 24. First sealing nut; 25. Positioning sleeve; 26. Servo valve core; 27. Servo valve sleeve; 28. First pressure spring; 29. Valve seat; 201. First opening of the solenoid proportional directional valve; 202. Second opening of the solenoid proportional directional valve;

[0031] 3. Valve body; P1, oil inlet; P2, oil outlet; T, unloading port. DETAILED DESCRIPTION

[0032] To make the purpose, technical solutions, and advantages of one or more embodiments of this specification more clear, the technical solutions of one or more embodiments of this specification will be clearly and completely described below in conjunction with the specific embodiments of this specification and the corresponding drawings. Obviously, the embodiments described are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of one or more embodiments of this specification.

[0033] The technical solutions provided by the embodiments of this specification are described in detail below with reference to the accompanying drawings.

[0034] The embodiment of this specification provides a proportional valve for a pump, which is used to connect with a pump to control the flow direction and flow rate of a liquid. Figures 1 to 2 As shown, the pump proportional valve may include a proportional relief valve 1 , an electromagnetic proportional directional valve 2 and a valve body 3 .

[0035] In the embodiment of this specification, the proportional relief valve 1 may include a plug screw 12 and a second sealing ring 16; wherein, the proportional relief valve 1 may be connected to the valve body 3 via the plug screw 12, so that the proportional relief valve may be built into the second chamber in the valve body; the second sealing ring 16 may be used to seal the connection between the plug screw 12 and the valve body 3 to prevent the liquid in the valve from overflowing, strengthen the connection between the proportional relief valve 1 and the valve body 3, and reduce the risk of the proportional relief valve falling off. Figure 1 The top of the connection between the middle screw plug and the valve body is also sealed with a sealing ring, but it is not marked.

[0036] In the embodiment of this specification, the second sealing nut 13 can be used to fix the cylindrical end set screw 14; the cylindrical end set screw 14 can be connected to the second pressure spring 15 through the spring seat 11; the second pressure spring 15 can be connected to the pressure valve core 10 through the spring seat 11, and the maximum pressure that the system can withstand can be set by the position of the cylindrical end set screw. The maximum pressure that the system can withstand can be called the set pressure, so that the system can be protected from overpressure damage based on the set pressure.

[0037] In the embodiment of this specification, an Allen wrench can be used to adjust the movement of the cylindrical end set screw 14. If the Allen wrench is used to adjust the cylindrical end set screw 14 to the right, the pressure of the left sub-spring seat in the spring seat 11 connected to the cylindrical end set screw 14 can be increased, thereby increasing the degree of spring compression, increasing the spring compression force, and increasing the set pressure. If the Allen wrench is used to adjust the cylindrical end set screw 14 to the left, the pressure of the left sub-spring seat in the spring seat 11 connected to the cylindrical end set screw 14 can be reduced, thereby reducing the degree of spring compression, reducing the spring compression force, and reducing the set pressure. The adjustable range of the set pressure is [0, 31.5] MPa.

[0038] In the embodiment of this specification, the electromagnetic proportional directional valve 2 may include a flange 20 and a first sealing ring 22; wherein, the electromagnetic proportional directional valve 2 may be connected to the valve body 3 via the flange 20, so that the electromagnetic proportional directional valve may be built into the first chamber within the valve body; the first sealing ring 22 may be used to seal the connection between the flange 20 and the valve body 3 to prevent liquid in the valve from overflowing, strengthen the connection between the electromagnetic proportional directional valve 2 and the valve body 3, and reduce the risk of the electromagnetic proportional directional valve falling off. Figure 1 The flange and the valve body are also sealed below the connection with a sealing ring, but it is not marked. The sealing ring used in the figure can be an annular sealing ring, also known as an O-ring.

[0039] In the embodiment of this specification, the servo valve core 26 is inserted into the axial hole of the servo valve sleeve 27; the proportional electromagnet 21 is connected to the servo valve core 26 through the flange 20; there is a push rod in the proportional electromagnet 21, and the compression degree of the first pressure spring 28 can be controlled by the extension and contraction of the push rod (the push rod is not in the Figure 1(shown in the figure). In actual applications, the engine speed sensor can transmit the speed to the electronic controller, which converts the engine speed into an electrical signal. This electrical signal controls the push rod in the proportional solenoid 21 to move leftward, compressing the first pressure spring. The first pressure spring, based on the pressure, pushes the servo valve core leftward, thereby changing the flow direction of the liquid in the electromagnetic proportional directional valve. The maximum distance the servo valve core can move is 2.2 mm. The servo valve sleeve protects the servo valve core. The servo valve sleeve and servo valve core are machined with μm-level precision, giving the valve port of the electromagnetic proportional directional valve zero coverage and increasing the control range.

[0040] In the embodiment of this specification, the first sealing nut 24 is used to secure the tapered set screw 23. An Allen wrench can be used to push the tapered set screw 23 up and down. When the Allen wrench is used to push the tapered set screw 23 downward, the tapered end of the tapered set screw pushes the valve seat 29 to the right, allowing the valve seat to push the first pressure spring 28 to the right. The first pressure spring pushes the servo valve core 26 to the right, thereby adjusting the initial position of the servo valve core 26. The position or travel distance of the servo valve core 26 can be determined using a positioning sleeve 25. It is understood that when power is off and the first pressure spring is compressed, moving the tapered set screw upward will cause the initial position of the servo valve core 26 to move to the left.

[0041] In the embodiment of this specification, the valve body includes an oil inlet P1, an oil outlet P2 and a unloading port T. P1 and P2 can be circular openings with a diameter of 5 mm; T can be an arc-shaped opening of 28 mm * 48 mm. These three openings can also be of other sizes, and the openings can be constructed according to actual needs. The interior of the valve body may include a first oil circuit, a second oil circuit and an oil return circuit. When the electromagnet is not energized, the flow of oil in the valve can be controlled through the first oil circuit; when the electromagnet is energized, the flow of oil in the valve can be controlled through the oil return circuit; when the system pressure exceeds the set pressure, the flow of oil in the valve can be controlled through the second oil circuit. It can be understood that in actual applications, oil can also flow in from the oil outlet on the valve body.

[0042] In the embodiments of this specification, the proportional relief valve may include a first opening 101 for oil inlet, a second opening 102 for oil outlet, a third opening for oil outlet, and a fourth opening for connecting to the oil outlet of the valve body. The third opening of the proportional relief valve is located at the rightmost end of the proportional relief valve; the fourth opening is located between the first opening 101 and the third opening of the proportional relief valve (the third and fourth openings of the proportional relief valve are not shown in the figure).

[0043] In the embodiments of this specification, the pressure valve core can be moved to control the flow between the first and second openings of the proportional relief valve; the flow between the first and fourth openings of the proportional relief valve; and the flow between the third and fourth openings of the proportional relief valve. In practical applications, the pressure valve core of the proportional relief valve has multiple notches. By pushing the pressure valve core to change the position of the notches, the flow of the internal oil circuit can be controlled, thereby achieving flow control between the openings. For example, if the first and second openings of the proportional relief valve are connected, then a notch on the pressure valve core can be located between the first and second openings of the proportional relief valve. If the first and second openings of the proportional relief valve are not connected, then none of the notches on the pressure valve core are located between the first and second openings of the proportional relief valve. In this case, the first internal oil circuit connecting the first and second openings of the proportional relief valve is disconnected. Similarly, the flow between the other openings can also be achieved in this manner, which will not be described in detail here. It can be understood that when the oil pressure at the slot is the same as the contraction pressure of the second pressure spring, the pressure valve core is in a stable state; when the oil pressure at the slot is greater than the contraction pressure of the second pressure spring, the pressure valve core can be pushed to the right, so that the contraction pressure of the second pressure spring increases, and the pressure valve core can stop moving when the contraction pressure of the second pressure spring reaches the same as the oil pressure at the slot.

[0044] In the embodiment of this specification, the electromagnetic proportional directional valve 2 may include a first opening 201 for oil inlet and a second opening 202 for oil outlet. Both the first and second openings of the electromagnetic proportional directional valve may be provided on the servo valve sleeve, with the first opening of the electromagnetic proportional directional valve located to the right of the second opening. The servo valve core 26 also has a notch, the position of which can be controlled by controlling the movement of the servo valve core. If the notch is located between the first and second openings of the electromagnetic proportional directional valve, the second internal oil circuit connecting the first and second openings of the electromagnetic proportional directional valve is in an open state. If the notch is not located between the first and second openings of the electromagnetic proportional directional valve, the second internal oil circuit connecting the first and second openings of the electromagnetic proportional directional valve is in a disconnected state.

[0045] In the embodiments of this specification, both the solenoid proportional directional valve and the proportional relief valve achieve internal circulation of the solenoid proportional directional valve or proportional relief valve through an internal oil circuit. Specifically, the first opening of the solenoid proportional directional valve is connected to the second opening of the solenoid proportional directional valve via a second internal oil circuit; the first opening of the proportional relief valve is connected to the second opening of the proportional relief valve via a first internal oil circuit; the fourth opening of the proportional relief valve is connected to the third opening of the proportional relief valve via a third internal oil circuit; and the first opening of the proportional relief valve is connected to the fourth opening of the proportional relief valve via a fourth internal oil circuit. It is understood that the internal oil circuit of the solenoid proportional directional valve or proportional relief valve is formed by the valve sleeve and the valve core; specifically, the gap between the valve sleeve and the valve core can be used as the internal oil circuit; it can also be understood that the notch of the valve core is used as the internal oil circuit.

[0046] In the embodiments of this specification, the electromagnetic proportional directional valve and the pressure cut-off valve can be connected through an external oil circuit in the valve body. The external oil circuit is also connected to the oil inlet, oil outlet, and unloading port on the valve body. Specifically, the oil inlet of the valve body is connected to the first opening of the proportional relief valve through the first external oil circuit; the second opening of the proportional relief valve is connected to the first opening of the electromagnetic proportional directional valve through the second external oil circuit; the second opening of the electromagnetic directional proportional valve is connected to the oil outlet of the valve body through the third external oil circuit; the oil outlet of the valve body is connected to the fourth opening of the proportional relief valve through the fourth external oil circuit; the third opening of the proportional relief valve is connected to the unloading port of the valve body through the fifth external oil circuit. It can be understood that the external oil circuit in the valve body is constructed by a pipeline. Specifically, there is an overlapping portion between the third external oil circuit and the fourth external oil circuit connected to the oil outlet of the valve body.

[0047] Figure 3 This is a hydraulic principle diagram of a proportional valve for a pump provided in the embodiment of this specification. Figure 3 and Figure 1 The cross-sectional structure diagram of the pump proportional valve is as follows. The working process of the pump proportional valve in the embodiment of this specification is as follows.

[0048] When the proportional solenoid 21 does not receive an electrical signal, the first pressure spring 28 is in a first preset position, so that the first notch on the servo valve core 26 is located between the first opening 201 and the second opening 202 of the electromagnetic proportional directional valve, and the second pressure spring 15 is in a second preset position, so that the second notch on the pressure valve core 10 is located between the first opening 101 and the second opening 102 of the proportional relief valve, and the third notch on the pressure valve core 10 is located between the third opening and the fourth opening of the proportional relief valve. At this time, the first oil passage can connect the oil inlet P1 and the oil outlet P2 on the valve body. Specifically, oil can enter the valve body through the oil inlet P1 and enter the proportional relief valve through the first external oil passage. The proportional relief valve flows out of the proportional relief valve through the first internal oil passage (the second notch) in the connected state, through the second opening 102 of the proportional relief valve, and then through the second external oil passage into the electromagnetic proportional directional valve through the first opening 201 of the electromagnetic proportional directional valve. The electromagnetic proportional directional valve flows out of the electromagnetic proportional directional valve through the second internal oil passage (the first notch) in the connected state, through the second opening 202 of the electromagnetic proportional directional valve, and through the third external oil passage out of the valve body through the oil outlet P2. It should be understood that the first notch, the second notch, and the third notch all refer to upper and lower notches at the same position on the valve core. For example, the first notch can have a sub-notch 1.5 mm above the valve core and a sub-notch 1.5 mm below the valve core.

[0049] When the proportional solenoid 21 receives an electrical signal, the first pressure spring 28 is in the third preset position, so that the first notch on the servo valve core 26 is not located between the first opening 201 and the second opening 202 of the electromagnetic proportional directional valve, and the second pressure spring 15 remains in the second preset position. At this point, the oil outlet P2 and the unloading port T on the valve body can be connected. Specifically, oil can flow from the valve body's oil outlet P2 through the first external oil circuit and the fourth opening of the proportional relief valve into the proportional relief valve. It then flows out of the proportional relief valve through the connected third internal oil circuit (the third notch) and the third opening of the proportional relief valve, and then through the fifth external oil circuit and the unloading port of the valve body into the oil tank. It is understood that when the solenoid receives an electrical signal, oil can still flow from the valve body's oil inlet and through the oil circuit from the proportional relief valve into the electromagnetic proportional directional valve; however, it cannot flow out of the electromagnetic proportional directional valve to the valve body's oil outlet.

[0050] When the proportional solenoid receives an electrical signal and the oil pressure at the second notch of the proportional relief valve exceeds the set pressure, the pressure on the left side of the second notch exceeds the spring's contraction pressure, pushing the pressure valve core 10 leftward to the fourth preset position. This positions the third notch between the fourth and first openings of the proportional relief valve. The internal oil circuit between the third and fourth openings of the proportional relief valve is disconnected, allowing the third oil circuit to connect the oil inlet P1 and oil outlet P2 on the valve body, reducing the pressure in the proportional valve. It is understood that the proportional relief valve has a higher priority than the solenoid proportional directional valve. If the set pressure is exceeded, the return oil circuit is disconnected, even if the proportional solenoid is still energized. Oil can enter the proportional relief valve from the valve body's oil inlet P1, through the first external oil circuit, and through the first opening 101 of the proportional relief valve. The oil then flows out of the proportional relief valve through the fourth internal oil circuit, out of the fourth outlet of the proportional relief valve, and out of the valve body's oil outlet through the fourth external oil circuit, reducing the internal oil pressure and oil flow, protecting the proportional valve from damage. It can be understood that when the set pressure is exceeded, the pressure on the right side of the first slot of the electromagnetic proportional directional valve is greater than the spring contraction pressure, which can push the servo valve core to the right, so that the second internal oil circuit of the electromagnetic proportional directional valve is opened, and the oil can flow through the first oil circuit.

[0051] The valve body's oil inlet can be connected to a small variable cylinder, its oil outlet to a large variable cylinder, and its unloading port to an oil tank. The oil circuit controls the piston movement of the large and small variable cylinders, as well as their ability to store oil. The operating state of the large and small variable cylinders controls the swing angle within the pump. The larger the swing angle, the greater the oil flow. In the first oil circuit, both large and small variable cylinders are in operation, with a swing angle of zero. Oil circulates through the first oil circuit and the externally connected large and small variable cylinders. In the return oil circuit, the swing angle gradually increases, increasing the oil flow. The small variable cylinder is in operation, while the large variable cylinder stops working. The pressure in the large variable cylinder reaches zero, and the oil in the large variable cylinder can flow into the oil tank through the return oil circuit. When the oil flow is excessive, or the oil pressure exceeds the set pressure, the second oil circuit is connected, placing the large variable cylinder in operation. The swing angle gradually decreases until it reaches zero, reducing the oil flow. This achieves a pressure cutoff, protecting the entire system from damage. Figure 3 The uppermost component is the proportional relief valve, and the component below the proportional relief valve is the electromagnetic proportional directional valve.

[0052] The pump proportional valve in the embodiment of this specification can use an electromagnetic proportional directional valve to change the direction of liquid flow, and can also use a proportional relief valve to protect the protection system from overpressure damage; it also integrates the electromagnetic proportional directional valve and the proportional relief valve into one, and can share the valve body and part of the oil circuit, reducing the space occupied by the two as a valve group; it can be directly disassembled through the connecting parts. Compared with the valve group, which requires disassembly of the connected pipes, the valves on both sides of the pump proportional valve can be directly disassembled without disassembly of the pipes, which is more convenient.

[0053] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0054] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0055] It should be noted that the terms "first", "second", etc. in the description and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0056] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A proportional valve for a pump, characterized in that: The pump proportional valve comprises: Valve body, electromagnetic proportional directional valve and proportional relief valve; the electromagnetic proportional directional valve and the proportional relief valve are connected through the valve body; The valve body includes a first chamber and a second chamber; the electromagnetic proportional directional valve is located in the first chamber; the proportional relief valve is located in the second chamber; The oil inlet of the valve body is communicated with the first opening of the proportional relief valve for oil inlet; the second opening of the proportional relief valve for oil outlet is communicated with the first opening of the electromagnetic proportional directional valve for oil inlet; the second opening of the electromagnetic proportional directional valve for oil outlet is communicated with the oil outlet of the valve body; the third opening of the proportional relief valve for oil outlet is communicated with the unloading port of the valve body.

2. The pump proportional valve according to claim 1, characterized in that: The valve body further includes a first oil circuit; the first oil circuit includes a first external oil circuit, a first internal oil circuit, a second external oil circuit, a second internal oil circuit and a third external oil circuit; The oil inlet of the valve body is connected to the first opening of the proportional relief valve through the first external oil circuit; the first opening of the proportional relief valve is connected to the second opening of the proportional relief valve through the first internal oil circuit; the second opening of the proportional relief valve is connected to the first opening of the electromagnetic proportional directional valve through the second external oil circuit; the first opening of the electromagnetic proportional directional valve is connected to the second opening of the electromagnetic proportional directional valve through the second internal oil circuit; the second opening of the electromagnetic directional proportional valve is connected to the oil outlet of the valve body through the third external oil circuit.

3. The pump proportional valve according to claim 1, characterized in that: The valve body also includes an oil return circuit; the oil return circuit includes a fourth external oil circuit, a third internal oil circuit and a fifth external oil circuit; the oil outlet of the valve body is connected to the fourth opening of the proportional relief valve through the fourth external oil circuit; the fourth opening of the proportional relief valve is connected to the third opening of the proportional relief valve through the third internal oil circuit; the third opening of the proportional relief valve is connected to the unloading port of the valve body through the fifth external oil circuit.

4. The pump proportional valve according to claim 1, characterized in that: The valve body further includes a second oil circuit; the second oil circuit includes a first external oil circuit, the fourth internal oil circuit and the fourth external oil circuit; The oil inlet of the valve body is connected to the first opening of the proportional relief valve through the first external oil circuit; the first opening of the proportional relief valve is connected to the fourth opening of the proportional relief valve through the fourth internal oil circuit; the fourth opening of the proportional relief valve is connected to the oil outlet of the valve body through the fourth external oil circuit.

5. The pump proportional valve according to claim 1, characterized in that: The electromagnetic proportional directional valve includes a flange and a first sealing ring; the flange is used to connect the electromagnetic proportional directional valve and the valve body; the first sealing ring is located between the flange and the valve body.

6. The pump proportional valve according to claim 5, characterized in that: The electromagnetic proportional directional valve also includes a proportional electromagnet and a servo valve core; The proportional electromagnet is used to push the servo valve core to move leftward; the servo valve core is used to control the on-off of the internal oil circuit of the electromagnetic proportional directional valve.

7. The pump proportional valve according to claim 5, characterized in that: The electromagnetic proportional directional valve further comprises a first sealing nut, a tapered set screw, a valve seat and a first pressure spring; The first sealing nut is used to fix the tapered end set screw; the tapered end set screw is used to adjust the position of the valve seat; the valve seat is used to control the compression degree of the first pressure spring; the first pressure spring is used to adjust the initial position of the servo valve core.

8. The pump proportional valve according to claim 1, characterized in that: The proportional relief valve further includes a screw plug and a second sealing ring; the screw plug is used to connect the proportional relief valve and the valve body; the second sealing ring is located between the screw plug and the valve body.

9. The method according to claim 8, wherein: The proportional relief valve further includes a screw plug, a pressure valve core, a second sealing nut, a cylindrical end set screw, and a second pressure spring; the screw plug is used to connect the proportional relief valve and the valve body; The second sealing nut is used to fix the cylindrical end set screw; the cylindrical end set screw is used to control the compression degree of the second pressure spring; the second pressure spring is used to control the position of the pressure valve core; the pressure valve core is used to control the on-off of the internal oil circuit of the proportional relief valve.

10. The pump proportional valve according to claim 9, characterized in that: Use an inner hexagonal wrench to adjust the position of the cylindrical end set screw.

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