CN114484014A

CN114484014A - Liquid pump pressure control valve

Info

Publication number: CN114484014A
Application number: CN202210082059.4A
Authority: CN
Inventors: 韦文术; 周华; 王伟; 卢海承; 于瑞; 马思宇; 胡经文
Original assignee: Ccteg Beijing Tianma Intelligent Control Technology Co ltd; Zhejiang University ZJU
Current assignee: Ccteg Beijing Tianma Intelligent Control Technology Co ltd; Zhejiang University ZJU
Priority date: 2022-01-24
Filing date: 2022-01-24
Publication date: 2022-05-13

Abstract

The invention discloses a liquid pump pressure control valve, which comprises a valve body, a pressure increasing valve core and an unloading valve core assembly, wherein a first cavity is arranged in the valve body, the unloading valve core is movable and comprises a first part, a second part and a third part which are sequentially connected, the cross sectional area of the first part is increased along the direction close to the second part, the cross sectional area of the third part is increased along the direction far away from the second part, the peripheral surface of the first part can be contacted with or separated from the first wall surface, and the peripheral surface of the third part can be contacted with or separated from the second wall surface. The liquid pump pressure control valve can inhibit the formation of cavitation flow, reduce the influence of cavitation erosion and prolong the service life.

Description

Liquid pump pressure control valve

Technical Field

The invention relates to the technical field of liquid pump equipment, in particular to a pressure control valve of a liquid pump.

Background

The pressure control valve is one of the key components of the pump station system, and the main function of the pressure control valve is to stabilize the working pressure of the pump within a specified pressure range. When the liquid pump pressure control valve in the related art is unloaded, the problem of large impact force of cavitation flow on the front surface of the cavity exists, so that the valve sleeve cracks and even breaks, and under the working conditions of high pressure, large flow and frequent opening and closing, cavitation not only can generate vibration and noise, but also can continuously damage the overflowing wall surface in a pulse mode along with gas, erode metal materials and shorten the service life of the liquid pump pressure control valve.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.

Therefore, the embodiment of the invention provides a liquid pump pressure control valve which can inhibit the formation of cavitation flow, reduce the cavitation influence and prolong the service life.

A liquid pump pressure control valve according to an embodiment of the present invention includes: the valve body is internally provided with a first cavity, a second cavity and a third cavity, and the first cavity is communicated with the second cavity and the third cavity respectively; the pressure increasing valve core is arranged in the second cavity and can move relative to the valve body; the unloading valve core assembly comprises an unloading sleeve body and an unloading valve core, the unloading sleeve body is arranged in the third cavity and is provided with a cavity communicated with the third cavity, the inner wall surface of the cavity comprises a first wall surface and a second wall surface which are arranged at intervals, the unloading valve core can move relative to the valve body, the unloading valve core comprises a first part, a second part and a third part which are sequentially connected along the length direction of the unloading valve core, the cross sectional area of the first part is increased along the direction close to the second part, the cross sectional area of the third part is increased along the direction far away from the second part, the peripheral surface of the first part can be in sealing contact with or separated from the first wall surface, and the peripheral surface of the third part can be in sealing contact with or separated from the second wall surface.

According to the liquid pump pressure control valve of the embodiment of the invention, the valve body comprises a first cavity communicated with the liquid inlet and a third cavity communicated with the unloading port, the first cavity is communicated with the third cavity through a cavity, the inner wall of the cavity comprises a first wall surface and a second wall surface which are separated, the unloading valve core comprises a first part, a second part and a third part which are sequentially connected, the sectional area of the first part is increased along the direction adjacent to the second part, the sectional area of the third part is increased along the direction away from the second part, the outer peripheral surface of the first part can be in sealing contact with or separated from the first wall surface of the cavity, the outer peripheral surface of the third part can be in sealing contact with or separated from the second wall surface of the second cavity, when the liquid pump is unloaded, a throttling channel can be formed between the outer peripheral surface of the first part and the first wall surface of the cavity, and a throttling channel can also be formed between the outer peripheral surface of the third part and the second wall surface of the cavity, therefore, the flow velocity and the flow of the hydraulic medium can be limited by utilizing the multi-stage throttling, the pressure reduction amplitude is reduced, the high-frequency burst of bubbles is avoided, the formation of cavitation flow is inhibited, the influence of cavitation on the unloading valve component and the valve sleeve is reduced, and the whole service life of the liquid pump pressure control valve is prolonged.

In some embodiments, the unloader valve spool is movable relative to the valve body between a first position in which the outer peripheral surface of the first portion is in mating and sealing contact with the first wall surface and a second position in which the outer peripheral surface of the third portion is in mating and sealing contact with the second wall surface; in the second position, the outer peripheral surface of the first portion is spaced apart from the first wall surface, the outer peripheral surface of the third portion is spaced apart from the second wall surface,

optionally, the cross-sectional area of the first portion increases progressively in a direction adjacent the second portion and the cross-sectional area of the third portion increases progressively in a direction away from the second portion.

In some embodiments, the cross-sectional area of the first portion increases in a direction adjacent to the second portion, and the cross-sectional area of the third portion increases in a direction away from the second portion.

In some embodiments, the outer peripheral surface of the second portion is provided with an annular recess, optionally, the outer peripheral surface of the second portion is an arc-shaped surface recessed inward.

In some embodiments, the first portion is provided with a first passage opening on an outer peripheral surface of the first portion, an end surface of an end of the first portion remote from the second portion is provided with a first through hole communicating with the first passage, and at least a part of the opening of the first passage is opposed to the first wall surface.

In some embodiments, the unloading sleeve body comprises a body and a protruding part arranged on the outer peripheral surface of the body, the cavity is arranged in the body, the protruding part is provided with a flow channel, and the flow channel penetrates through the protruding part to communicate the third cavity and the cavity; optionally, an included angle α is formed between the extending direction of the flow channel and the extending direction of the body, and α is greater than 0 degree and smaller than 90 degrees.

In some embodiments, the flow passages are plural, the plural flow passages are divided into plural rows, each row of the flow passages includes plural flow passages arranged at intervals along the circumferential direction of the projection, and the centers of the flow passages of adjacent rows are spaced apart in both the extending direction of the body and the axial direction of the body.

In some embodiments, the unloading sleeve body comprises a first sleeve body and a second sleeve body which are sequentially arranged in the length direction of the unloading sleeve body, the cavity comprises a first cavity and a second cavity, the first cavity forms the first sleeve body, the second cavity forms the second sleeve body, the inner wall surface of the first cavity comprises the first wall surface, the inner wall surface of the second cavity comprises the second wall surface, and the first sleeve body and the second sleeve body are integrally formed, or the first sleeve body and the second sleeve body are formed in a split mode.

In some embodiments, the unloading valve core assembly further comprises a sealing element, the sealing element is positioned between the unloading valve core and the unloading sleeve body in the radial direction of the unloading valve core,

optionally, an annular groove is formed in the inner wall surface of the unloading sleeve body, and the sealing element is arranged in the annular groove.

In some embodiments, the unloading valve core assembly further includes an elastic member, the elastic member is disposed in the cavity, one end of the elastic member is connected to an end of the unloading valve core away from the first cavity, and the elastic member has an elastic force pushing the unloading valve core towards the first cavity.

In some embodiments, the liquid pump pressure control valve further comprises: the pressure boost sleeve body is arranged in the second cavity, the pressure boost valve core is arranged in the second cavity, and the pressure boost sleeve body and the unloading sleeve body are integrally formed;

and/or the electromagnetic pilot valve is arranged on the valve body and can control the unloading valve core to be opened and closed through the electromagnetic action.

Drawings

FIG. 1 is a rear view of a liquid pump pressure control valve according to an embodiment of the present invention.

FIG. 2 is a front view of a liquid pump pressure control valve according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a liquid pump pressure control valve according to an embodiment of the present invention.

Fig. 4 is a partial structural sectional view of a liquid pump pressure control valve according to an embodiment of the present invention.

Fig. 5 is an enlarged view of a portion a in fig. 4.

Reference numerals are as follows:

a valve body 1; a first cavity 11; a third cavity 12; a cavity 13; a first wall 131; a second wall 132; the projecting portion 14; a flow channel 141; a second cavity 15; a pressure increasing valve core 16; a pressure jacket body 161; a liquid inlet 17; a liquid outlet 18; an unloading port 19;

the unloading valve core component 2; an unloading sleeve body 21; an unloading spool 22; a first portion 221; a second portion 222; a third portion 223; a first channel 24; an elastic member 25;

an electromagnetic pilot valve 3.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

As shown in fig. 1 to 4, a liquid pump pressure control valve according to an embodiment of the present invention includes a valve body 1, a pressure increasing spool 16, and an unloading spool assembly 2.

As shown in fig. 3 and 4, the valve body 1 has a first cavity 11, a second cavity 15, and a third cavity 12 therein, and the first cavity 11 is communicated with the second cavity 15, and the third cavity 12 is communicated with the second cavity 15. Further, as shown in fig. 1 and fig. 2, a liquid inlet 17, a liquid outlet 18 and an unloading port 19 are provided on the valve body 1, the first cavity 11 is communicated with the liquid inlet 17, the second cavity 15 is communicated with the liquid outlet 18, the third cavity 12 is communicated with the unloading port 19, and the pressure boost valve core 16 is provided in the second cavity 15 and is movable relative to the valve body 1 to block or open inlets of the second cavity 15 and the first cavity 11.

As shown in fig. 3 to 5, the unloading valve core assembly 2 includes an unloading sleeve body 21 and an unloading valve core 22, the unloading sleeve body 21 is disposed in the third cavity 12, an inner wall surface of the cavity 13 includes a first wall surface 131 and a second wall surface 132 which are arranged at an interval, the unloading valve assembly has an open state and a close device, and in a start state, the unloading valve core 22 is movable relative to the valve body 1.

Specifically, it is defined that the unloading valve core 22 is movable between a first position and a second position to open and close the entrance of the cavity 13, and in the first position, the end of the unloading valve core 22 facing the first cavity 11 may block the entrance of the cavity 13, and the unloading valve core 22 includes a first portion 221, a second portion 222 and a third portion 223 connected in sequence along the length direction thereof, the cross-sectional area of the first portion 221 increases in a direction adjacent to the second portion 222, and the cross-sectional area of the third portion 223 increases in a direction away from the second portion 222.

Specifically, as shown in fig. 3, the valve body 1 includes a body and a protrusion 14 provided on an outer peripheral surface of the body, the cavity 13 is provided in the body, the protrusion 14 is provided with a flow passage 141, the flow passage 141 penetrates through the protrusion 14 to communicate the third cavity 12 and the cavity 13, and the first cavity 11 communicates with the third cavity 12 through the cavity 13 and the flow passage 141. Optionally, an angle α is formed between the extending direction of the flow channel 141 and the extending direction of the body, and α is greater than 0 degree and less than 90 degrees. In other words, the flow channel 141 is an inclined flow channel 141, so that the streamline distribution of the flow field can be improved, and bubbles can be prevented from being broken at the position of the wall surface of the valve sleeve, thereby inhibiting the cavitation phenomenon.

It will be appreciated that the unloader spool 22 is movable to block or unblock the inlets of the first chamber 11 and the cavity 13, and in the first position, the outer peripheral surface of the first portion 221 is in mating and sealing contact with the first wall 131, and the outer peripheral surface of the third portion 223 is in mating and sealing contact with the second wall 132. In other words, in the first position, the first portion 221 blocks the inlet of the cavity 13 and the first chamber 11, the first chamber 11 and the third chamber 12 are disconnected, and the liquid pump is loaded.

Further, in the second position, the outer peripheral surface of the first portion 221 is separated from the first wall surface 131, and the outer peripheral surface of the third portion 223 is separated from the second wall surface 132. In other words, in the second position, the first portion 221 opens the inlet of the cavity 13 and the third cavity 12, the first cavity 11 and the third cavity 12 are connected and the liquid pump is unloaded.

In addition, the cross-sectional area of the first portion 221 of the present application increases in a direction adjacent to the second portion 222, and the cross-sectional area of the third portion 223 increases in a direction away from the second portion 222. It will be appreciated that the cross-sectional area of the first portion 221 and the cross-sectional area of the third portion 223 both increase in a direction away from the first cavity, i.e. there are at least two gradients between the outer circumference of the first portion 221, the outer circumference of the second portion 222 and the outer circumference of the third portion 223.

It will be appreciated that in the second position, the separation of the outer peripheral surface of the first portion 221 from the first wall surface 131 forms a throttling passage therebetween, and the separation of the outer peripheral surface of the third portion 223 from the second wall surface 132 forms a throttling passage therebetween, so that a multi-stage throttling can be achieved when the liquid pump is controlled to unload by using the unloading valve cartridge 22 of the present application.

Specifically, in practical application, when the liquid pump pressure control valve is in an initial state, the end of the pressure increasing valve core 16 facing the first cavity 11 blocks the inlets of the first cavity 11 and the second cavity 15, that is, the first cavity 11 is not communicated with the second cavity 15, the liquid inlet 17 is not communicated with the liquid outlet 18, and the liquid outlet 18 is in a closed state, when the working surface is filled with oil, the pressure increasing valve core 16 moves under the action of the pressure of the hydraulic medium in the first cavity 11, so that the end of the pressure increasing valve core 16 is moved away from the inlet of the first cavity and the second cavity, at this time, the liquid inlet 17 is communicated with the liquid outlet 18, and the liquid outlet 18 is in an open state.

Further, when the unloading valve core 22 is in a closed state, the end part of the unloading valve core 22 facing the first cavity 11 blocks and keeps the inlets of the first cavity 11 and the cavity 13, the unloading port 19 is not communicated with the liquid inlet 17, when the unloading valve core 22 is in an open state, the unloading valve core 22 blocks and initially blocks the inlet of the cavity 13, the liquid inlet 17 is not communicated with the unloading port 19, the unloading port 19 is in a closed state, and then the unloading valve core 22 moves along with the pressure of the hydraulic medium in the first cavity 11 to open the inlets of the first cavity 11 and the cavity 13, so that the liquid inlet 17 is communicated with the unloading port 19, and the unloading port 19 is opened.

It should be noted that, the liquid pump pressure control valve is used as a protection structure of a liquid pump to be fully applied in the related field, however, the inventor finds that, when the liquid pump pressure control valve in the related art is unloaded, a hydraulic medium directly flows to a low-pressure region at a high speed and in a large amount, so that the external pressure of bubbles in the medium is suddenly reduced, thereby causing centralized bursting of the bubbles, and the bursting of the bubbles can continuously and pulsingly damage a flow wall surface, erode a metal material, so that pit-shaped pitting corrosion gradually occurs on the metal material, and the smoothness of a metal inner wall is reduced, the roughness is increased, and the metal inner wall is more and more easily eroded.

In the application, when the liquid pump is unloaded, the peripheral surface of the unloading valve core 22 and the inner wall surface of the cavity 13 can define a multi-stage throttling channel, so that the flow speed and the flow of the hydraulic medium are limited by using multi-stage throttling when the liquid pump is unloaded, the pressure reduction amplitude is reduced, the high-frequency burst of bubbles is avoided, and the influence of cavitation on the unloading valve is reduced.

Further, as shown in fig. 4 and 5, the cross-sectional area of the first portion 221 gradually increases in a direction adjacent to the second portion 222, and the cross-sectional area of the third portion 223 gradually increases in a direction away from the second portion 222.

In other words, the throttle passage extending obliquely may be formed between the outer peripheral surface of the first portion 221 and the first wall surface 131, and the throttle passage extending obliquely may be formed between the outer peripheral surface of the second portion 222 and the second wall surface 132, which is advantageous for further suppressing cavitation.

Further, as shown in fig. 5, the outer peripheral surface of the second portion 222 is provided with an annular recess. Therefore, the annular concave part can form a cavitation entrainment structure to inhibit cavitation erosion under large opening. Optionally, the bottom wall surface of the annular recess is an inwardly recessed arc surface.

Further, as shown in fig. 4 and 5, the first portion 221 is provided with a first passage 24 that opens on the outer peripheral surface of the first portion 221, an end surface of the first portion 221 at an end remote from the second portion 222 is provided with a first through hole that communicates with the first passage 24, and at least a part of the opening of the first passage 24 is opposed to the first wall surface 131. In other words, when the liquid pump is unloaded, a part of the hydraulic medium in the first chamber 11 can directly flow into the throttle passage formed by the first portion 221 and the first wall surface 131 through the first passage 24, thereby reducing the pressure change gradient at the time of unloading and suppressing the cavitation phenomenon.

In some embodiments, the flow channels 141 are plural, the plurality of flow channels 141 are divided into a plurality of rows, each row of flow channels 141 includes a plurality of flow channels 141 arranged at intervals along the circumferential direction of the projection 14, and centers of the flow channels 141 of adjacent rows are spaced apart in both the extending direction of the body and the axial direction of the body.

Further, as shown in fig. 4, the unloading sleeve body 21 includes a first sleeve body and a second sleeve body which are sequentially arranged in the length direction thereof, the cavity 13 includes a first cavity 13 and a second cavity 13, the first cavity 13 is formed in the first sleeve body, the second cavity 13 is formed in the second sleeve body, the inner wall surface of the first cavity 13 includes a first wall surface 131, and the inner wall surface of the second cavity 13 includes a second wall surface 132.

As shown in fig. 3, the first cavity 13 communicates with the first chamber 11, and the second cavity 13 communicates with the third chamber 12 through the flow passage 141. Optionally, the first sleeve body and the second sleeve body are integrally formed, or the first sleeve body and the second sleeve body are separately formed.

In some embodiments, the unloading valve core assembly 2 further comprises a seal located between the unloading valve core 22 and the unloading sleeve body 21 in a radial direction of the unloading valve core 22. Optionally, an annular groove is formed in the inner wall surface of the unloading sleeve body 21, and the sealing element is arranged in the annular groove.

Further, as shown in fig. 3 and 4, the unloading valve core assembly 2 further includes an elastic member 25, the elastic member 25 is disposed in the cavity 13, one end of the elastic member 25 is connected to one end of the unloading valve core 22 away from the first cavity 11, and the elastic member 25 has an elastic force that pushes the unloading valve core 22 toward the first cavity 11. Specifically, when the liquid pump is unloaded, the hydraulic medium in the first cavity 11 presses the unloading valve core 22 to move in a direction away from the first cavity 11 so as to open inlets of the first cavity 11 and the cavity 13, so that the first cavity 11 and the third cavity 12 are communicated, unloading is completed, the unloading valve core 22 compresses the elastic member 25 in a direction away from the first cavity 11, when the liquid pump is loaded, the first cavity 11 supplies oil to the second cavity 15, and the elastic member 25 rebounds to drive the unloading valve core 22 to move in a direction towards the first cavity 11 so as to block the inlets of the first cavity 11 and the cavity 13.

Further, as shown in fig. 4, the liquid pump pressure control valve further includes a pressure boost sleeve 161, the pressure boost sleeve 161 is disposed in the second cavity 15, the pressure boost valve core 16 is disposed in the second cavity 15, and the pressure boost sleeve 161 and the unloading sleeve 21 are integrally formed, so as to improve the structural strength and further improve the overall service life of the liquid pump pressure control valve.

Further, as shown in fig. 1 and fig. 2, the liquid pump pressure control valve further includes an electromagnetic pilot valve, which is disposed on the valve body 1 and can control the opening and closing of the unloading valve core 22 through electromagnetic action.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the present disclosure, the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" and the like mean that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A hydraulic pump pressure control valve, comprising:

the valve body is internally provided with a first cavity, a second cavity and a third cavity, and the first cavity is communicated with the second cavity and the third cavity respectively;

the pressure increasing valve core is arranged in the second cavity and can move relative to the valve body;

the unloading valve core assembly comprises an unloading sleeve body and an unloading valve core, the unloading sleeve body is arranged in the third cavity and is provided with a cavity communicated with the third cavity, the inner wall surface of the cavity comprises a first wall surface and a second wall surface which are arranged at intervals, the unloading valve core can move relative to the valve body, the unloading valve core comprises a first part, a second part and a third part which are sequentially connected along the length direction of the unloading valve core, the cross section area of the first part is increased along the direction close to the second part, the cross section area of the third part is increased along the direction far away from the second part, the peripheral surface of the first part can be in sealing contact with or separated from the first wall surface, and the peripheral surface of the third part can be in sealing contact with or separated from the second wall surface.

2. The liquid pump pressure control valve of claim 1, wherein the unloader spool is movable relative to the valve body between a first position in which an outer peripheral surface of the first portion is in mating and sealing contact with the first wall surface and a second position in which an outer peripheral surface of the third portion is in mating and sealing contact with the second wall surface; in the second position, the outer peripheral surface of the first portion is separated from the first wall surface, the outer peripheral surface of the third portion is separated from the second wall surface,

3. The liquid pump pressure control valve according to claim 1, wherein the outer peripheral surface of the second portion is provided with an annular recess,

optionally, the outer peripheral surface of the second portion is an arc surface recessed inward.

4. A liquid pump pressure control valve according to claim 1, wherein the first portion is provided with a first passage that opens at an outer peripheral surface of the first portion, an end surface of the first portion at an end remote from the second portion is provided with a first through hole that communicates with the first passage, and at least a portion of the opening of the first passage is opposed to the first wall surface.

5. The liquid pump pressure control valve according to claim 1, wherein the unloading sleeve body includes a body and a protrusion provided on an outer peripheral surface of the body, the cavity is provided in the body, the protrusion is provided with a flow passage that penetrates the protrusion to communicate the third cavity with the cavity;

optionally, an included angle α is formed between the extending direction of the flow channel and the extending direction of the body, and α is greater than 0 degree and smaller than 90 degrees.

6. The liquid pump pressure control valve according to claim 5, wherein the flow passage is plural, the plural flow passages are divided into plural rows, each row of the flow passages includes plural flow passages arranged at intervals in a circumferential direction of the projection, centers of the flow passages of adjacent rows are spaced apart in both an extending direction of the body and an axial direction of the body.

7. The liquid pump pressure control valve according to claim 1, wherein the relief sleeve body includes a first sleeve body and a second sleeve body arranged in this order in the length direction thereof, the cavity includes a first cavity and a second cavity, the first cavity is formed in the first sleeve body, the second cavity is formed in the second sleeve body, the inner wall surface of the first cavity includes the first wall surface, the inner wall surface of the second cavity includes the second wall surface,

the first sleeve body and the second sleeve body are integrally formed, or the first sleeve body and the second sleeve body are formed in a split mode.

8. The liquid pump pressure control valve of claim 1, wherein the unloading spool assembly further includes a seal located radially of the unloading spool between the unloading spool and the unloading sleeve body,

9. The liquid pump pressure control valve according to any one of claims 1 to 8, wherein the unloading valve core assembly further includes an elastic member, the elastic member is disposed in the cavity, one end of the elastic member is connected to an end of the unloading valve core away from the first cavity, and the elastic member has an elastic force urging the unloading valve core in a direction toward the first cavity.

10. The liquid pump pressure control valve according to any one of claims 1-8, further comprising:

the pressure boost sleeve body is arranged in the second cavity, the pressure boost valve core is arranged in the second cavity, and the pressure boost sleeve body and the unloading sleeve body are integrally formed;