CN117189206A - Proportional valve and control method thereof - Google Patents

Abstract

The invention discloses a proportional valve and a control method based on the proportional valve, wherein the proportional valve comprises a valve body, a liquid inlet valve core, a liquid return valve core and a pilot loop, an inner cavity extending along the length direction of the valve body is arranged in the valve body, one end of the inner cavity is communicated with the outer side of the valve body to form a liquid outlet, and the valve body is also provided with a liquid inlet, a liquid return port and a control port; the liquid inlet valve core is slidably arranged in the inner cavity, the liquid return valve core is arranged on one side of the liquid inlet valve core, which is away from the liquid outlet, a through hole is formed in the liquid inlet valve core so as to be communicated with the liquid inlet and the liquid outlet, the liquid return valve core can slide in the inner cavity, and one end of the liquid return valve core can push the liquid inlet valve core; the pilot loop is connected with the inner cavity and connected with one side of the liquid return valve core, which is away from the liquid inlet valve core, through the control port, and the pilot loop is provided with a first pressure reducing valve. The proportional valve provided by the embodiment of the invention has the advantages of higher control reliability and higher adjustment precision.

Description

Proportional valve and control method thereof

Technical Field

The invention relates to the technical field of valve equipment, in particular to a proportional valve and a control method based on the proportional valve.

Background

The hydraulic support is key supporting equipment of a fully-mechanized coal mining face, and the existing hydraulic support is controlled by a switch-type electrohydraulic reversing valve to perform actions such as lifting and pushing. Because the bracket and the load inertia are large, when the switching-type electrohydraulic reversing valve is in quick reversing, the flow mutation can cause huge hydraulic impact, cause equipment and pipelines to vibrate, even damage hydraulic elements and systems, and seriously affect production. Meanwhile, in order to ensure the supporting effect, the hydraulic support is required to be subjected to posture adjustment by small flow, but the flow is large and uncontrollable when the switch-type electrohydraulic reversing valve is started, and the accurate posture adjustment of the support cannot be ensured. The hydraulic valve in the related art cannot realize stepless proportional control and cannot achieve the purpose of continuously adjusting the flow.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems in the related art to some extent. For this reason, the embodiment of the invention provides a proportional valve, which has the advantages of higher control reliability and higher adjustment precision.

The proportional valve comprises a valve body, wherein an inner cavity extending along the length direction of the valve body is arranged in the valve body, one end of the inner cavity is communicated with the outer side of the valve body to form a liquid outlet, the valve body is further provided with a liquid inlet, a liquid return port and a control port, the liquid inlet is arranged between the liquid outlet and the liquid return port, and the liquid return port is arranged between the liquid inlet and the control port; the liquid inlet valve core and the liquid return valve core are slidably arranged in the inner cavity, the liquid return valve core is arranged on one side, deviating from the liquid outlet, of the liquid inlet valve core, a through hole is formed in the liquid inlet valve core so as to be communicated with the liquid inlet and the liquid outlet, the liquid return valve core can slide in the inner cavity so as to open and close the liquid return port, and one end of the liquid return valve core can push the liquid inlet valve core to open and close the through hole; the pilot loop is connected with the inner cavity and connected with one side of the liquid return valve core, which is away from the liquid inlet valve core, through the control port, and is provided with a first pressure reducing valve, and the first pressure reducing valve is suitable for adjusting the pressure of one side of the liquid return valve core, which is away from the liquid inlet valve core, so as to drive the liquid return valve core.

The pilot circuit of the proportional valve is provided with the first pressure reducing valve so as to reduce the pressure of liquid medium which enters the pilot circuit and is introduced into the inner cavity of one side of the liquid return valve core, which is far away from the liquid inlet valve core, and the liquid medium pressure which drives the liquid return valve core to move is controlled by the first pressure reducing valve, so that the on-off of the liquid return port and the flow area between the liquid inlet and the liquid outlet are controlled. Compared with the proportional valve in the related art which adopts a high-speed switch valve, the proportional valve provided by the embodiment of the invention has the advantages of simplicity in control and higher control precision.

The control of the liquid return valve core can simultaneously realize the functions of controlling the on-off of the liquid return port and controlling the flow area between the liquid inlet and the liquid outlet, and compared with the control of the liquid return valve core and the liquid inlet valve core of the proportional valve in the related art, the proportional valve has the advantages of simple control and further improvement of control precision.

In some embodiments, the inner cavity comprises a control cavity, the control cavity is arranged at one end of the liquid return valve core, which is away from the liquid inlet valve core, the pilot loop is connected with the control cavity through a control port, and the pilot loop can supply liquid medium into the control cavity or discharge the liquid medium in the control cavity so as to drive the liquid return valve core to slide.

In some embodiments, the inner cavity further comprises a liquid inlet cavity and a liquid return cavity, a liquid outlet cavity is arranged in the liquid inlet valve core, the liquid outlet cavity penetrates through the liquid inlet valve core along the length direction of the liquid inlet valve core, the liquid inlet cavity and the liquid outlet cavity can be communicated through the through holes, the liquid return cavity and the liquid outlet cavity can be communicated through one end of the liquid outlet cavity, and the other end of the liquid outlet cavity is connected with the liquid outlet for discharging liquid medium.

In some embodiments, an elastic member is disposed on an outer peripheral side of the liquid inlet valve core, so as to push the liquid inlet valve core along a direction towards the liquid return valve core, the liquid return valve core may be abutted to an end portion of the liquid inlet valve core so as to isolate the liquid outlet cavity from the liquid return cavity, an outer peripheral wall of the liquid inlet valve core may be slidably matched with an inner wall of a part of the inner cavity, and the liquid return valve core may push the liquid inlet valve core to move against the action of the elastic member under the action of the pressure of the liquid medium in the control cavity so as to be suitable for opening and closing the through hole.

In some embodiments, a guide sleeve is arranged in the valve body, the outer edge of the guide sleeve is assembled on the inner wall of the inner cavity, the liquid inlet valve core is slidably and hermetically assembled on the inner edge of the guide sleeve, the guide sleeve is arranged between the liquid inlet and the liquid return opening, and the guide sleeve is in sealing connection with the valve body and in sealing connection with the liquid inlet valve core so as to isolate the liquid inlet cavity from the liquid return cavity.

In some embodiments, the pilot circuit includes a supply line and a return line, the supply line being connected to the inlet and the control port, the return line being connected to the return port, and the first pressure relief valve being disposed between the supply line and the control port.

In some embodiments, the first pressure reducing valve is a two-position three-way pressure reducing valve, an outlet end of the first pressure reducing valve is communicated with the control port, a first liquid inlet end of the first pressure reducing valve is connected with the liquid supply pipeline, a second liquid inlet end of the first pressure reducing valve is connected with the liquid return pipeline, and the first pressure reducing valve can enable the control port to be communicated with the liquid supply pipeline or enable the control port to be communicated with the liquid return pipeline.

In some embodiments, the pilot circuit includes a second pressure relief valve disposed between the supply line and the first pressure relief valve;

the pilot loop comprises a pressure relief valve, and the pressure relief valve is connected with a first liquid inlet end of the first pressure relief valve to relieve pressure.

In some embodiments, the proportional valve further includes a displacement sensor, a first pressure sensor and a second pressure sensor, where the displacement sensor is disposed at an end of the liquid return valve core away from the liquid inlet valve core, the first pressure sensor is disposed at the liquid outlet, and the second pressure sensor is disposed at the liquid inlet, so as to be suitable for detecting displacement of the liquid return valve core, pressure of the liquid outlet and pressure of the liquid inlet.

The control method of the proportional valve according to the embodiment of the invention is based on any one of the proportional valves, and comprises the following steps:

experiments are carried out by using the proportional valve provided by the embodiment of the invention to obtain the linear relation among the pressure of the liquid outlet end of the first pressure reducing valve, the stroke of the liquid return valve core and the flow between the liquid inlet and the liquid outlet;

opening a first pressure reducing valve to connect the control cavity with the liquid supply pipeline, and adjusting the pressure in the control cavity by adjusting the pressure of the liquid outlet end of the first pressure reducing valve;

and adjusting the pressure of the liquid outlet end of the first pressure reducing valve according to the difference between the actual flow between the liquid inlet and the liquid outlet and the expected flow between the liquid inlet and the liquid outlet until the actual flow between the liquid inlet and the liquid outlet reaches the expected flow between the liquid inlet and the liquid outlet.

Drawings

Fig. 1 is a schematic structural view of a proportional valve according to an embodiment of the present invention.

Fig. 2 is a schematic view of a valve body of a proportional valve according to an embodiment of the present invention.

Reference numerals:

a valve body 1; a plug 11; a groove 111; a sleeve 12; a liquid inlet 13; a liquid return port 14; a control port 15; a liquid outlet 16; a lumen 100; a liquid inlet chamber 101; a liquid return chamber 102; a control chamber 103;

a liquid inlet valve core 2; a through-flow hole 21; an elastic member 22; a liquid outlet cavity 23;

a liquid return valve core 3; a boss 31;

a pilot circuit 4; a first pressure reducing valve 41; a second pressure reducing valve 42; a pressure release valve 43;

a liquid supply line 5; a liquid return pipeline 6; a displacement sensor 7; a first pressure sensor 8; a second pressure sensor 9.

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 by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.

The proportional valve according to the embodiment of the present invention is described below with reference to fig. 1 and 2.

The proportional valve of the embodiment of the invention comprises a valve body 1, a liquid inlet valve core 2, a liquid return valve core 3 and a pilot loop 4.

An inner cavity 100 extending along the length direction of the valve body is arranged in the valve body 1, one end of the inner cavity 100 is communicated with the outer side of the valve body 1 to form a liquid outlet 16, the valve body 1 is further provided with a liquid inlet 13, a liquid return port 14 and a control port 15, the liquid inlet 13 is arranged between the liquid outlet 16 and the liquid return port 14, and the liquid return port 14 is arranged between the liquid inlet 13 and the control port 15.

Specifically, as shown in fig. 2, the valve body 1 extends in the left-right direction, an inner cavity 100 is provided in the valve body 1, the inner cavity 100 extends in the left-right direction, and the left end of the inner cavity 100 penetrates through the left end of the valve body 1, so that the left end of the inner cavity 100 communicates with the outside of the valve body 1 and forms a liquid outlet 16 for the liquid medium to flow out from the left end of the inner cavity 100.

The liquid inlet 13, the liquid return opening 14 and the control opening 15 are all arranged on the outer peripheral side of the valve body 1, the liquid inlet 13, the liquid return opening 14 and the control hole are arranged at intervals along the left-to-right direction, and the liquid inlet 13, the liquid return opening 14 and the control opening 15 are communicated with the inner cavity 100 for liquid to enter and exit the inner cavity 100.

The liquid inlet valve core 2 is slidably arranged in the inner cavity 100, the liquid return valve core 3 is arranged on one side of the liquid inlet valve core 2, which is away from the liquid outlet 16, the liquid inlet valve core 2 is provided with a through hole 21 for communicating the liquid inlet 13 and the liquid outlet 16, the liquid return valve core 3 can slide in the inner cavity 100 to open and close the liquid return port 14, and one end of the liquid return valve core 3 can prop against the liquid inlet valve core 2 to open and close the through hole 21.

Specifically, the liquid inlet valve core 2 extends in the left-right direction, and the liquid inlet valve core 2 can slide in the left-right direction in the inner cavity 100, and in the process of sliding the liquid inlet valve core 2 in the left-right direction, the flow area between the liquid inlet 13 and the liquid outlet 16 can be controlled, so that the liquid medium entering the valve body 1 from the liquid inlet can flow out from the liquid outlet 16, and the flow rate in the process of flowing the liquid medium from the liquid inlet 13 to the liquid outlet 16 is regulated, so that the flow rate proportion regulation is realized.

The liquid return valve is arranged between the liquid inlet 13 and the control port 15, the control port 15 is arranged at one end of the liquid return valve core 3 deviating from the liquid inlet valve core 2, the pressure of liquid medium entering one side of the liquid return valve core 3 deviating from the liquid inlet valve core 2 is regulated through the control port 15, the liquid return valve core 3 is driven to move in the inner cavity 100, in the moving stroke of the liquid return valve core 3, the liquid return valve core 3 can control the on-off of the liquid return port 14 so as to open and close the liquid return port 14, the liquid medium in the inner cavity 100 is discharged into the liquid return pipeline 6 along the liquid return port 14, and the liquid return valve core 3 can be stopped against the liquid inlet valve core 2 and push the liquid inlet valve core 2 so that the liquid inlet valve core 2 slides in the inner cavity 100 and the flow area between the liquid inlet 13 and the liquid outlet 16 is controlled.

The pilot circuit 4 is connected to the inner chamber 100 and to the side of the return spool 3 facing away from the inlet spool 2 via the control port 15, the pilot circuit 4 being provided with a first pressure reducing valve 41, the first pressure reducing valve 41 being adapted to regulate the pressure of the side of the return spool 3 facing away from the inlet spool 2 for driving the return spool 3.

Specifically, the pilot circuit 4 is communicated with the inner cavity 100 through the control port 15, the control port 15 is located at one side of the liquid return valve core 3, which is away from the liquid inlet valve core 2, liquid medium can be introduced into the inner cavity 100 at one side of the liquid return valve core 3, which is away from the liquid inlet valve core 2, through the pilot circuit 4 so as to drive the liquid return valve core 3 to move towards the liquid inlet valve core 2, the outlet pressure of the first pressure reducing valve 41 is adjustable, and therefore the pressure of the liquid medium introduced into the inner cavity 100 at one side of the liquid return valve core 3, which is away from the liquid inlet valve core 2, of the pilot circuit 4 is adjusted, and the stroke of the liquid return valve core 3 is adjusted.

The pilot circuit 4 of the proportional valve of the embodiment of the invention is provided with the first pressure reducing valve 41 to reduce the pressure of the liquid medium flowing into the inner cavity 100 of the pilot circuit 4 on one side of the liquid return valve core 3 away from the liquid inlet valve core 2, and the pressure of the liquid medium driving the liquid return valve core 3 to move is controlled by the first pressure reducing valve 41, so that the on-off of the liquid return port 14 and the flow area between the liquid inlet 13 and the liquid outlet 16 are controlled. Compared with the proportional valve in the related art which adopts a high-speed switch valve, the proportional valve provided by the embodiment of the invention has the advantages of simplicity in control and higher control precision.

The control of the liquid return valve core 3 can simultaneously realize the functions of controlling the on-off of the liquid return port 14 and controlling the flow area between the liquid inlet 13 and the liquid outlet 16, and compared with the control of the liquid return valve core 3 and the liquid inlet valve core 2 of the proportional valve in the related art, the proportional valve provided by the embodiment of the invention has the advantages of simple control and further improvement of control precision.

In some embodiments, the inner cavity 100 includes a control cavity 103, the control cavity 103 is disposed at an end of the liquid return valve core 3 away from the liquid inlet valve core 2, the pilot circuit 4 is connected with the control cavity 103 through the control port 15, and the pilot circuit 4 can supply liquid medium into the control cavity 103 or discharge liquid medium in the control cavity 103 so as to drive the liquid return valve core 3 to slide.

Specifically, the liquid return valve core 3 is assembled in the inner cavity 100, a control cavity 103 is formed on the right side of the liquid return valve core 3, and the control port 15 is arranged in the control cavity 103 so that the pilot circuit 4 is communicated with the control cavity 103.

The right end of the liquid return valve core 3 is provided with a boss 31, the boss 31 extends along the left-right direction, the diameter of the boss 31 is smaller than that of the liquid return valve core 3 at the rest, the right end of the inner cavity 100 is provided with a plug 11 for plugging the right end of the inner cavity 100, a groove 111 is arranged in the plug 11, the groove 111 extends along the left-right direction, the inner diameter of the groove 111 is smaller than that of the inner cavity 100, and the boss 31 is assembled in the groove 111 through shaft hole matching.

Therefore, the boss 31 with smaller diameter is matched in the groove 111 with smaller inner diameter, the machining precision of the boss 31 with smaller diameter matched in the groove 111 with smaller inner diameter is higher, and the forming quality of the boss 31 with smaller diameter matched in the groove 111 with smaller inner diameter is easy to control, so that the guidance quality of the liquid return valve core 3 in sliding in the left-right direction is improved.

In some embodiments, the inner cavity 100 further includes a liquid inlet cavity 101 and a liquid return cavity 102, the liquid outlet cavity 23 is disposed in the liquid inlet valve core 2, the liquid outlet cavity 23 penetrates through the liquid inlet valve core 2 along the length direction of the liquid inlet valve core 2, the liquid inlet cavity 101 and the liquid outlet cavity 23 can be communicated through the through hole 21, the liquid return cavity 102 and the liquid outlet cavity 23 can be communicated through one end of the liquid outlet cavity 23, and the other end of the liquid outlet cavity 23 is connected with the liquid outlet 16 for discharging liquid medium.

Specifically, the liquid inlet 101 is disposed on the left side of the liquid return cavity 102, the liquid inlet 13 is disposed in the liquid inlet 101, the liquid return port 14 is disposed in the liquid return cavity 102, the liquid inlet valve core 2 is of a cylindrical structure, openings are disposed at the left end and the right end of the liquid inlet valve core 2, the liquid outlet cavity 23 is formed in the liquid inlet valve core 2, so that liquid medium can enter the liquid return cavity 102 from the liquid inlet 13 into the valve body 1, then pass through the liquid outlet cavity 23 of the through hole 21 and then be discharged to the liquid outlet 16 from the left end of the liquid outlet cavity 23, and the right end of the liquid inlet 101 can be communicated with the liquid return cavity 102 so as to enable the liquid medium in the liquid inlet 101 to enter the liquid return cavity 102 and be discharged to the liquid return port 14.

In some embodiments, the outer peripheral side of the liquid inlet valve core 2 is provided with an elastic member 22 to push the liquid inlet valve core 2 along the direction towards the liquid return valve core 3, the liquid return valve core 3 can be abutted against the end of the liquid inlet valve core 2 to isolate the liquid outlet cavity 23 from the liquid return cavity 102, the outer peripheral wall of the liquid inlet valve core 2 can be slidably matched with the inner wall of a part of the inner cavity 100, and the liquid return valve core 3 can push the liquid inlet valve core 2 to move against the action of the elastic member 22 under the action of the pressure of liquid medium in the control cavity 103 so as to be suitable for opening and closing the through hole 21.

Specifically, the elastic member 22 is a spring, the elastic member 22 extends along the left-right direction, the left end of the elastic member 22 is abutted against the valve body 1, the right end of the elastic member 22 is abutted against the liquid inlet valve core 2, the elastic member 22 is compressed between the liquid inlet valve core 2 and the valve body 1 so as to apply rightward acting force to the liquid inlet valve core 2, the liquid medium in the control cavity 103 applies leftward thrust to the liquid return valve core 3 so as to push the liquid inlet valve core 2 through the liquid return valve core 3, the acting force of the elastic member 22 to the liquid inlet valve core 2 is overcome, and then the liquid inlet valve core 2 is pushed to move.

It can be understood that, as the intake valve core 2 moves to the left, the acting force of the elastic member 22 on the intake valve core 2 gradually increases, and by setting the pressure of the liquid medium in the control chamber 103, the intake valve core 2 receives the leftward thrust force the same as the acting force of the elastic member 22 on the intake valve core 2 when the intake valve core 2 is in the set stroke, so that the acting force of the intake valve core 2 is balanced when the intake valve core 2 is in the set stroke, and the intake valve core 2 is stationary in the set position.

Therefore, the moving stroke of the liquid inlet valve core 2 under the pushing of the liquid return valve core 3 can be adjusted by adjusting the pressure of the liquid medium in the control cavity 103 through the first pressure reducing valve 41, so that the flow area of the through hole 21 can be controlled through the first pressure reducing valve 41, and the flow between the liquid inlet 13 and the liquid outlet 16 of the proportional valve in the embodiment of the invention can be controlled through the first pressure reducing valve 41.

In some embodiments, a guide sleeve 12 is arranged in the valve body 1, the outer edge of the guide sleeve 12 is assembled on the inner wall of the inner cavity 100, the liquid inlet valve core 2 is slidably and hermetically assembled on the inner edge of the guide sleeve 12, the guide sleeve 12 is arranged between the liquid inlet 13 and the liquid return 14, and the guide sleeve 12 is hermetically connected with the valve body 1 and the guide sleeve 12 is hermetically connected with the liquid inlet valve core 2 so as to isolate the liquid inlet cavity 101 and the liquid return cavity 102.

Therefore, by arranging the guide sleeve 12 between the valve body 1 and the liquid inlet valve core 2, the inner wall of the guide sleeve 12 is in sealing and sliding connection with the outer wall of the liquid inlet valve core 2, the outer peripheral wall of the guide sleeve 12 is in sealing and fixed connection with the inner wall of the inner cavity 100, on one hand, the length of the sealing connection between the liquid inlet valve core 2 and the valve body 1 can be reduced, so that the tightness between the liquid inlet valve core 2 and the valve body 1 is improved, and on the other hand, the liquid inlet 13 and the liquid return 14 can be isolated, and the liquid inlet 13 and the liquid return 14 can only be connected through the liquid outlet cavity 23 inside the liquid inlet valve core 2.

In some embodiments, the pilot circuit 4 comprises a supply line 5 and a return line 6, the supply line 5 being connected to the inlet 13 and the control 15, the return line 6 being connected to the return 14, and a first pressure relief valve 41 being provided between the supply line 5 and the control 15.

Specifically, the liquid supply line 5 communicates with the liquid inlet 101 of the inner cavity 100 through the liquid inlet 13 to supply a liquid medium having a pressure into the inner cavity 100, and the liquid return line 6 communicates with the liquid return chamber 102 of the inner cavity 100 through the liquid return port 14 to discharge the liquid medium in the inner cavity 100 to release the pressure.

In some embodiments, the first pressure reducing valve 41 is a two-position three-way pressure reducing valve, the outlet end of the first pressure reducing valve 41 is communicated with the control port 15, the first liquid inlet end of the first pressure reducing valve 41 is connected with the liquid supply pipeline 5, the second liquid inlet end of the first pressure reducing valve 41 is connected with the liquid return pipeline 6, and the first pressure reducing valve 41 can enable the control port 15 to be communicated with the liquid supply pipeline 5 or enable the control port 15 to be communicated with the liquid return pipeline 6.

Specifically, the first pressure reducing valve 41 has a first state in which an outlet end of the first pressure reducing valve 41 is connected to the first liquid inlet end to communicate the control port 15 with the liquid supply line 5 for the liquid medium to enter the control chamber 103, and a second state in which the pressure of the liquid medium discharged at the control port 15 is adjustable to adjust the pressure of the liquid medium in the control chamber 103.

In the second state, the outlet end of the first pressure reducing valve 41 is connected with the second liquid inlet end, so that the control port 15 is communicated with the liquid return pipeline 6, so that the liquid medium in the control cavity 103 is discharged into the liquid return pipeline 6 through the first pressure reducing valve 41, and at the moment, the pressure on the left side of the liquid return valve core 3 is greater than the pressure on the right side of the liquid return valve core 3, and the liquid return valve core 3 moves rightwards to reset.

In some embodiments, the pilot circuit 4 comprises a second pressure relief valve 42, the second pressure relief valve 42 being arranged between the liquid supply line 5 and the first pressure relief valve 41;

the pilot circuit 4 includes a pressure relief valve 43, and the pressure relief valve 43 is connected to the first liquid inlet end of the first pressure relief valve 41 to relieve pressure.

Specifically, the second pressure reducing valve 42 is provided between the liquid supply line 5 and the first liquid inlet end of the first pressure reducing valve 41 to reduce the pressure of the liquid medium entering the first pressure reducing valve 41 from the liquid supply line 5, the outlet end pressure of the first pressure reducing valve 41 is adjustable, and the pressure releasing valve 43 is connected between the first pressure reducing valve 41 and the second pressure reducing valve 42 to discharge the liquid medium between the first pressure reducing valve 41 and the second pressure reducing valve 42 to release the pressure when the pressure at the first liquid inlet end of the first pressure reducing valve 41 is greater than the set pressure.

Therefore, the pressure of the liquid medium entering the first pressure reducing valve 41 is regulated through the second pressure reducing valve 42 and the pressure releasing valve 43, on one hand, the pressure regulating range of the first pressure reducing valve 41 can be reduced, so that the pressure regulating precision of the first pressure reducing valve 41 is improved, and the proportional valve provided by the embodiment of the invention has the advantage of higher regulating precision, on the other hand, the liquid entering the control cavity 103 from the liquid supply pipeline 5 is subjected to secondary pressure reduction through the first pressure reducing valve 41 and the second pressure reducing valve 42, and the proportional valve provided by the embodiment of the invention can work in a higher pressure environment of the liquid supply pipeline 5.

In some embodiments, the proportional valve further comprises a displacement sensor 7, a first pressure sensor 8 and a second pressure sensor 9, wherein the displacement sensor 7 is arranged at one end of the liquid return valve core 3, which is away from the liquid inlet valve core 2, the first pressure sensor 8 is arranged at the liquid outlet 16, and the second pressure sensor 9 is arranged at the liquid inlet 13, so that the displacement of the liquid return valve core 3, the pressure of the liquid outlet 16 and the pressure of the liquid inlet 13 are suitable for detection.

The control method of the proportional valve according to the embodiment of the invention is based on the proportional valve of any one of the above, and comprises the following steps:

experiments are carried out by using the proportional valve provided by the embodiment of the invention, so that the linear relation among the pressure of the liquid outlet end of the first pressure reducing valve 41, the stroke of the liquid return valve core 3 and the flow between the liquid inlet 13 and the liquid outlet 16 is obtained;

opening the first pressure reducing valve 41 to connect the control chamber 103 with the liquid supply pipeline 5, and adjusting the pressure in the control chamber 103 by adjusting the pressure of the liquid outlet end of the first pressure reducing valve 41;

the outlet end pressure of the first pressure reducing valve 41 is adjusted according to the difference between the actual flow rate between the inlet 13 and the outlet 16 and the desired flow rate between the inlet 13 and the outlet 16 until the actual flow rate between the inlet 13 and the outlet 16 reaches the desired flow rate between the inlet 13 and the outlet 16.

Specifically, the pressure at the liquid outlet end of the first pressure reducing valve 41 of the proportional valve according to the embodiment of the present invention is adjustable, by adjusting the pressure at the liquid outlet end of the first pressure reducing valve 41, the liquid return valve core 3 is driven to move toward the liquid inlet valve core 2 to close the liquid return port 14, and the liquid return valve core 3 can move against the liquid inlet valve core 2, and the pressure in the control chamber 103 is adjusted by the first pressure reducing valve 41 to adjust the travel of the liquid inlet valve core 2, so as to adjust the flow area between the liquid inlet 13 and the liquid outlet 16, and further adjust the opening of the proportional valve according to the embodiment of the present invention.

According to the proportional valve disclosed by the embodiment of the invention, the stroke of the liquid inlet valve core 2 is controlled by adjusting the pressure of the control cavity 103, and the flow area between the liquid inlet 13 and the liquid outlet 16 is adjusted by adjusting the stroke of the liquid inlet valve core 2, so that the linear relationship exists among the stroke of the liquid inlet valve core 2, the flow between the liquid inlet 13 and the liquid outlet 16 and the pressure of the control cavity 103.

When the proportional valve of the embodiment of the invention is controlled, the flow between the liquid inlet 13 and the liquid outlet 16 can be obtained according to the stroke of the liquid inlet valve core 2, so that when the set flow between the liquid inlet 13 and the liquid outlet 16 is expected to be obtained, the liquid outlet end pressure of the first pressure reducing valve 41 is regulated, and the stroke of the liquid inlet valve core 2 is monitored until the stroke of the liquid inlet valve core 2 reaches the stroke of the liquid inlet valve core 2 corresponding to the set flow between the liquid inlet 13 and the liquid outlet 16.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

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

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

For purposes of this disclosure, the terms "one embodiment," "some embodiments," "example," "a particular example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms are not necessarily directed 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, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

While the above embodiments have been shown and described, it should be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives, and variations of the above embodiments may be made by those of ordinary skill in the art without departing from the scope of the invention.

Claims (10)

1. A proportional valve, comprising:

the valve body is internally provided with an inner cavity extending along the length direction of the valve body, one end of the inner cavity is communicated with the outer side of the valve body to form a liquid outlet, the valve body is also provided with a liquid inlet, a liquid return port and a control port, the liquid inlet is arranged between the liquid outlet and the liquid return port, and the liquid return port is arranged between the liquid inlet and the control port;

the liquid inlet valve core and the liquid return valve core are slidably arranged in the inner cavity, the liquid return valve core is arranged on one side, deviating from the liquid outlet, of the liquid inlet valve core, a through hole is formed in the liquid inlet valve core so as to be communicated with the liquid inlet and the liquid outlet, the liquid return valve core can slide in the inner cavity so as to open and close the liquid return port, and one end of the liquid return valve core can push the liquid inlet valve core to open and close the through hole;

the pilot loop is connected with the inner cavity and connected with one side of the liquid return valve core, which is away from the liquid inlet valve core, through the control port, and is provided with a first pressure reducing valve, and the first pressure reducing valve is suitable for adjusting the pressure of one side of the liquid return valve core, which is away from the liquid inlet valve core, so as to drive the liquid return valve core.

2. The proportional valve of claim 1, wherein the inner cavity comprises a control cavity, the control cavity is arranged at one end of the liquid return valve core, which is away from the liquid inlet valve core, the pilot loop is connected with the control cavity through a control port, and the pilot loop can supply liquid medium into the control cavity or discharge liquid medium in the control cavity so as to drive the liquid return valve core to slide.

3. The proportioning valve of claim 2 wherein said internal cavity further comprises a liquid inlet cavity and a liquid return cavity, a liquid outlet cavity is disposed in said liquid inlet valve core, said liquid outlet cavity extends through said liquid inlet valve core along the length direction of said liquid inlet valve core, said liquid inlet cavity and said liquid outlet cavity are communicable through said through-flow holes, said liquid return cavity and said liquid outlet cavity are communicable through one end of said liquid outlet cavity, and the other end of said liquid outlet cavity is connected with said liquid outlet for discharging liquid medium.

4. The proportioning valve of claim 3 wherein an elastic member is disposed on a peripheral side of said liquid inlet valve element for urging said liquid inlet valve element in a direction toward said liquid return valve element, said liquid return valve element being adapted to abut against an end of said liquid inlet valve element to isolate said liquid outlet chamber from said liquid return chamber, a peripheral wall of said liquid inlet valve element being slidably engaged with an inner wall of a portion of said inner chamber, said liquid return valve element being adapted to urge said liquid inlet valve element against movement of said elastic member under the action of liquid medium pressure in said control chamber for closing said through-flow aperture.

5. The proportioning valve of claim 3 wherein a guide sleeve is disposed within said valve body, said outer edge of said guide sleeve being mounted to said inner wall of said inner cavity, said liquid inlet valve element being slidably and sealingly mounted to said inner edge of said guide sleeve, said guide sleeve being disposed between said liquid inlet and liquid return ports, and said guide sleeve being sealingly connected to said valve body and said guide sleeve being sealingly connected to said liquid inlet valve element to isolate said liquid inlet from said liquid return chamber.

6. The proportional valve of claim 2, wherein the pilot circuit comprises a supply line and a return line, the supply line being connected to the inlet and the control port, the return line being connected to the return port, and the first pressure relief valve being disposed between the supply line and the control port.

7. The proportioning valve of claim 6 wherein said first pressure relief valve is a two-position three-way pressure relief valve, an outlet port of said first pressure relief valve is in communication with said control port, a first inlet port of said first pressure relief valve is in communication with said supply line, a second inlet port of said first pressure relief valve is in communication with said return line, and said first pressure relief valve enables said control port to be in communication with said supply line or said control port to be in communication with said return line.

8. The proportional valve of claim 7, wherein the pilot circuit comprises a second pressure relief valve disposed between the supply line and the first pressure relief valve;

the pilot loop comprises a pressure relief valve, and the pressure relief valve is connected with a first liquid inlet end of the first pressure relief valve to relieve pressure.

9. The proportional valve of claim 2, further comprising a displacement sensor, a first pressure sensor and a second pressure sensor, wherein the displacement sensor is disposed at an end of the return spool facing away from the inlet spool, the first pressure sensor is disposed at the outlet, and the second pressure sensor is disposed at the inlet to be adapted to detect displacement of the return spool, the outlet pressure and the inlet pressure.

10. A control method based on a proportional valve as claimed in any one of claims 2 to 9, comprising the steps of:

experiments are carried out by using the proportional valve provided by the embodiment of the invention to obtain the linear relation among the pressure of the liquid outlet end of the first pressure reducing valve, the stroke of the liquid return valve core and the flow between the liquid inlet and the liquid outlet;

opening a first pressure reducing valve to connect the control cavity with the liquid supply pipeline, and adjusting the pressure in the control cavity by adjusting the pressure of the liquid outlet end of the first pressure reducing valve;

and adjusting the pressure of the liquid outlet end of the first pressure reducing valve according to the difference between the actual flow between the liquid inlet and the liquid outlet and the expected flow between the liquid inlet and the liquid outlet until the actual flow between the liquid inlet and the liquid outlet reaches the expected flow between the liquid inlet and the liquid outlet.