A dual-proportional high water-based proportional valve

Abstract

The present invention discloses a dual-proportional high-water-base proportional valve. A return valve core is slidingly provided at the left end of the housing of the dual-proportional high-water-base proportional valve, and a valve sleeve is fixedly installed at the right end. A valve seat and a load valve core are arranged in the valve sleeve; the inner cavity of the return valve core, the valve seat, and the load valve core is connected to the load end A port; an inlet flow channel is formed between the valve seat and the load valve core, and a return flow channel is formed between the return valve core and the inner wall of the housing. An annular control chamber and an annular control protrusion that slide and seal with each other are provided between the load valve core and the valve sleeve. The annular control protrusion divides the annular control chamber into a left control chamber and a right control chamber. The pressure difference between the left control chamber and the right control chamber drives the load valve core to slide, thereby enabling the dual-proportional high-water-base proportional valve to switch between working positions and proportionally control the flow in the dual working positions. The dual-proportional high-water-base proportional valve of the present invention has good control in both the PA working position and the AT working position, has a low degree of freedom, and can achieve a proportional effect.

Description

Technical Field

[0001] The present invention relates to the technical field of proportional valve design, and in particular to a dual-proportional high-water-based proportional valve. Background Art

[0002] A high-water-base proportional valve is a hydraulic valve used to regulate the flow of pure water or emulsion media, primarily used in explosion-proof environments such as coal mines. The high-water-base hydraulic cylinders in the hydraulic system of the Muzuo fully mechanized mining face are primarily controlled by on-off valve timing, which often results in over-extension or over-retraction of the cylinders, making it difficult to maintain the posture control of the hydraulic support. To overcome the bottleneck of precise posture control of the hydraulic support, a high-water-base proportional valve with stepless flow control was urgently needed.

[0003] Existing high-water-based proportional valves are divided into three categories. The first category is controlled by a high-speed switching valve pilot, such as CN116607989A (a water-based proportional valve) and CN111894924A (a high-water-based, high-pressure, and large-flow digital proportional directional valve with manual and automatic control); the second category is controlled by a motor pilot, such as CN109555740B (a water-based proportional valve and its control method) and CN117329189A (a follow-up pilot water-based proportional valve); the third category is a hydraulically balanced solution controlled by a pilot pressure reducing valve, such as CN113685387B (a pressure-balanced water-based proportional reversing valve) and CN115653961A (a high-water-based proportional directional valve and its working method).

[0004] Due to the requirements for mining sealing, the above solutions are all proportional valves with a two-position three-way cone valve structure, but the return oil working position is all on-off type, and only the oil inlet working position is proportional. There is room for improvement in control freedom and energy saving. Summary of the Invention

[0005] The present invention addresses the problem that existing water-based proportional valves only have a unilateral proportional function and provides a dual-proportional high-water-based proportional valve. The water-based proportional valve of the present invention has the advantages of dual proportions of liquid inlet and liquid return, easy load independent control and energy saving.

[0006] The technical solution adopted in the present invention is:

[0007] 1. A dual-proportional high water-based proportional valve

[0008] The dual-proportional high-water-based proportional valve includes a housing and a load valve core, a valve sleeve, a valve seat and a liquid return valve core coaxially arranged inside the housing; the housing is provided with a liquid return T port, a liquid inlet P port, a left control chamber K1 port, a right control chamber K2 port and a load end A port.

[0009] A liquid return valve core is slidingly arranged at the left end of the shell, and a valve sleeve is arranged at the right end. A valve seat and a load valve core are slidingly arranged in the valve sleeve from left to right in sequence; the valve sleeve is fixedly connected to the shell, and the inner cavity of the liquid return valve core, the inner cavity of the valve seat, the inner cavity of the load valve core and the load end A port are connected.

[0010] A liquid inlet flow channel is formed between the valve seat and the load valve core. The sliding of the load valve core causes the liquid inlet flow channel to be opened or closed. The opening of the liquid inlet flow channel causes the liquid inlet port P to be connected to the inner cavity of the valve seat. A liquid return flow channel is formed between the liquid return valve core and the inner wall of the shell. The sliding of the liquid return valve core causes the liquid return flow channel to be opened or closed. The opening of the liquid return flow channel causes the liquid return port T to be connected to the inner cavity of the valve seat.

[0011] An annular control chamber and an annular control protrusion that slide and seal with each other are provided between the load valve core and the valve sleeve. The annular control protrusion divides the annular control chamber into a left control chamber and a right control chamber. The left control chamber is connected to the left control chamber K1 port, and the right control chamber is connected to the right control chamber K2 port. The pressure difference between the left control chamber and the right control chamber drives the load valve core to slide, thereby enabling the dual-proportional high-water-based proportional valve to switch between the intermediate working position, the PA working position and the AT working position, and proportionally control the flow in the PA working position and the AT working position.

[0012] In the middle working position, the return liquid flow channel and the liquid inlet flow channel are closed, and the return liquid T port, the liquid inlet P port and the load end A port are not connected to each other; in the PA working position, the return liquid flow channel is closed, the liquid inlet flow channel is connected, and the liquid inlet P port and the load end A port are connected; in the AT working position, the return liquid flow channel is connected, the liquid inlet flow channel is closed, and the return liquid T port and the load end A port are connected.

[0013] The dual-proportional high-water-based proportional valve also includes a load spring arranged in the inner cavity of the load valve core, and a return spring and a valve seat reset spring arranged in the inner cavity of the return valve core; the two ends of the load spring respectively press against the inner end surface of the right end of the shell and the inner end surface of the left end of the load valve core; the two ends of the return spring respectively press against the inner end surface of the left end of the shell and the inner end surface of the right end of the return valve core; the two ends of the valve seat reset spring respectively press against the inner end surface of the left end of the shell and the outer end surface of the left end of the valve seat.

[0014] The valve seat is mainly composed of a left working section, an intermediate working section and a right working section, the outer diameters of which increase successively; the right working section and the load valve core form a liquid inlet channel on the left side of the liquid inlet P port; the right working section is provided with a flange, which is slidably arranged in an annular limiting cavity, and the annular limiting cavity is mainly enclosed by the outer wall of the valve seat and the stepped groove on the inner wall of the valve sleeve, and a through hole is provided on the inner wall of the groove bottom of the stepped groove, so that the annular limiting cavity is connected with the liquid inlet P port; the outer wall surface of the intermediate working section is slidably sealed with the inner wall surface of the shell or the valve sleeve; the left working section extends into the return liquid valve core and is slidably sealed with the return liquid valve core, and the outer end surface of the left working section serves as a support surface for the valve seat reset spring.

[0015] The return liquid valve core and the shoulder on the inner side of the shell form a return liquid flow channel on the right side of the return liquid T-port. The center of the right end surface of the return liquid valve core extends axially toward the right to form an extension portion with a smaller diameter. The extension portion of the return liquid valve core is sleeved on the outer side of the left working section of the valve seat, and the middle working section of the valve seat and the extension portion of the return liquid valve core are arranged at intervals; a return liquid cavity is formed between the extension portion of the return liquid valve core and the inner wall of the shell, and the return liquid cavity is connected with the return liquid T-port through the return liquid flow channel. A number of through holes are opened on the end surface of the middle working section of the valve seat, so that the return liquid cavity is connected with the inner cavity of the valve seat.

[0016] The center of the left end surface of the load valve core extends axially toward the left side to form an extension portion with a smaller diameter, and the extension portion of the load valve core extends into the inner cavity of the valve seat; a plurality of first connecting holes are formed around the outer circumferential surface of the extension portion of the load valve core, and a second connecting hole is formed on the left end surface, so that the inner cavity of the load valve core is connected with the inner cavity of the valve seat.

[0017] The outer circumference of the valve sleeve is provided with a first annular groove and a second annular groove, and the first annular groove and the second annular groove are respectively connected to the left control chamber K1 port and the right control chamber K2 port; the inner wall of the valve sleeve is provided with a third annular groove, and the third annular groove and the load valve core form an annular control chamber; the inner wall of the groove bottom of the first annular groove is provided with a plurality of circumferentially distributed through holes, so that the left control chamber K1 port, the first annular groove and the left control chamber in the annular control chamber are connected; the inner wall of the groove bottom of the second annular groove is provided with a plurality of circumferentially distributed through holes, so that the right control chamber K2 port, the second annular groove and the right control chamber in the annular control chamber are connected.

[0018] A fourth annular groove is provided on the outer periphery of the valve sleeve, which is connected to the liquid inlet P port. The inner wall of the bottom of the fourth annular groove is provided with a plurality of circumferentially distributed through holes, so that the liquid inlet P port, the fourth annular groove and the liquid inlet channel are connected.

[0019] The shell is mainly formed by sealingly connecting a left end cover, an outer shell and a right end cover.

[0020] There is always a gap between the liquid return valve core and the inner wall surface of the left end of the shell; there is always a gap between the load valve core and the inner wall surface of the right end of the shell.

[0021] 2. A control method using the above-mentioned dual-proportional high-water-base proportional valve

[0022] The following steps are involved:

[0023] The pressures in the left and right control chambers are kept the same or are pressure-free, so that the annular control protrusion is located in the center of the annular control chamber, the flange on the right working section of the valve seat abuts against the right side wall of the annular limit chamber, the right end face of the right working section of the valve seat is sealed against the left end face of the load valve core, the liquid inlet flow channel is closed, the right end face of the liquid return valve core is sealed against the left side face of the shoulder inside the housing, the liquid return flow channel is closed, and the proportional valve is in the middle working position, and the liquid return port T, the liquid inlet port P and the load end port A are not connected to each other;

[0024] The liquid pressure in the left control chamber is increased so that the pressure in the left control chamber is greater than that in the right control chamber. The pressure difference between the left and right control chambers overcomes the elastic force of the load spring on the load valve core, driving the load valve core to move rightward. The right end surface of the right working section of the valve seat separates from the left end surface of the load valve core, the liquid inlet flow channel is connected, and the liquid inlet port P, the liquid inlet flow channel, the inner cavity of the valve seat, the inner cavity of the load valve core, and the load end port A are connected, thereby switching the proportional valve to the PA working position, and the liquid inlet port P is connected to the load end port A. In the PA working position, the pressure at the left control chamber K1 port is adjusted according to the target flow rate until the flow rate of the liquid outflowing from the load end port A reaches the target flow rate.

[0025] Increasing the liquid pressure in the right control chamber makes the pressure in the left control chamber lower than that in the right control chamber. The pressure difference between the left control chamber and the right control chamber overcomes the elastic force of the valve seat return spring on the valve seat, driving the load valve core to drive the valve seat to move left synchronously. The pressure difference between the left control chamber and the right control chamber overcomes the sum of the elastic forces of the return spring and the valve seat return spring, driving the load valve core to drive the valve seat and the return valve core to move left synchronously, so that the right end face of the return valve core is separated from the left side face of the shoulder on the inner side of the shell, the return liquid flow channel is connected, the return liquid T port, the return liquid flow channel, the return liquid chamber, the inner cavity of the valve seat, the inner cavity of the load valve core and the load end A port are connected, thereby switching the proportional valve to the AT working position, and the return liquid T port is connected to the load end A port; in the AT working position, the pressure of the left control chamber K1 port is adjusted according to the target flow until the flow rate of the liquid outflowing from the return liquid T port reaches the target flow rate.

[0026] The beneficial effects of the present invention are as follows:

[0027] The present invention designs a dual-proportional high-water-base proportional valve, which overcomes the problem that the existing high-water-base proportional valve only has a proportional effect in the PA working position, while the AT working position switch control has a low control freedom, is conducive to realizing independent control of the valve port and reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the structure of the dual-proportional high-water-base proportional valve in the present invention at the middle working position;

[0029] Figure 2 Schematic diagram of the structure of the dual-proportional high water-based proportional valve in the present invention in the PA working position;

[0030] Figure 3 It is a partial enlarged view of the main valve port (liquid inlet P port) of the dual-proportional high water-based proportional valve of the present invention;

[0031] Figure 4 It is a structural schematic diagram of the dual-proportional high water-based proportional valve in the present invention in the AT working position.

[0032] In the figure: 1. Left end cover, 2. Housing, 2.1. Liquid return port T, 2.2. Liquid inlet port P, 2.3. Left control chamber K1 port, 2.4. Right control chamber K2 port, 3. Right end cover, 3.1. Load end port A, 4. Load spring, 5. Load valve core, 6. Valve sleeve, 7. Valve seat, 8. Liquid return valve core, 9. Liquid return spring, 10. Valve seat return spring. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] A first aspect of the present invention provides a dual-proportional high-water-based proportional valve.

[0035] The dual-proportional high water-based proportional valve of the present invention comprises a housing and a load valve core 5, a valve sleeve 6, a valve seat 7 and a liquid return valve core 8 coaxially arranged inside the housing. Figure 1 As shown, the outer wall of the housing is provided with, from left to right, a return liquid T port 2.1, a liquid inlet P port 2.2, a left control chamber K1 port 2.3, and a right control chamber K2 port 2.4. A load port A port 3.1 is provided at the right end of the housing. Specifically, the return liquid T port 2.1, the liquid inlet P port 2.2, the left control chamber K1 port 2.3, and the right control chamber K2 port 2.4 are all provided radially along the dual-proportional high-water-base proportional valve, while the load port A port 3.1 is provided axially along the dual-proportional high-water-base proportional valve.

[0036] A liquid return valve core 8 is slidably provided at the left end of the interior of the housing, and a valve sleeve 6 is arranged at the right end of the interior of the housing. A valve seat 7 and a load valve core 5 are slidably arranged in the valve sleeve 6 from left to right. The valve sleeve 6 is fixedly connected to the housing. The inner cavity of the liquid return valve core 8, the inner cavity of the valve seat 7, the inner cavity of the load valve core 5 and the load end A port 3.1 are connected.

[0037] The housing is internally provided with a return liquid channel and a liquid inlet channel, each connected to the return liquid port 2.1 and the liquid inlet port 2.2, respectively. Specifically, a liquid inlet channel is formed between the valve seat 7 and the load valve core 5. The sliding of the load valve core 5 opens or closes the liquid inlet channel. The opening of the liquid inlet channel connects the liquid inlet port 2.2 with the inner cavity of the valve seat 7, thereby sequentially connecting the liquid inlet port 2.2, the liquid inlet channel, the inner cavity of the valve seat 7, the inner cavity of the load valve core 5, and the load end A port 3.1. A liquid return channel is formed between the return liquid valve core 8 and the inner wall of the housing. The sliding of the return liquid valve core 8 opens or closes the liquid return channel. The opening of the liquid return channel connects the return liquid port 2.1 with the inner cavity of the valve seat 7, thereby sequentially connecting the return liquid port 2.1, the liquid return channel, the inner cavity of the valve seat 7, the inner cavity of the load valve core 5, and the load end A port 3.1.

[0038] In a specific implementation, the liquid return valve core 8 and the shoulder on the inner wall of the shell form a liquid return flow channel.

[0039] In a specific implementation, the liquid inlet channel is located on the left side of the liquid inlet P port 2.2, and the liquid return channel is located on the right side of the liquid return T port 2.1.

[0040] The dual-proportional high-water-base proportional valve switches operating states and controls flow through the axial left-right movement of the load valve core 5. This left-right movement is controlled by the pressure differential between the left control chamber K1 port 2.3 and the right control chamber K2 port 2.4. This left-right movement is achieved by providing an annular control chamber between the load valve core 5 and the valve sleeve 6. An annular control protrusion is disposed on the outside of the load valve core 5. The outer surface of the annular control protrusion forms a sliding, sealing engagement with the inner surface of the annular control chamber. The annular control protrusion divides the annular control chamber into a left control chamber and a right control chamber. The left and right control chambers are disconnected from each other. The left control chamber communicates with the left control chamber K1 port 2.3, while the right control chamber communicates with the right control chamber K2 port 2.4. The pressure differential between the left and right control chambers drives the load valve core 5 to slide, thereby switching the proportional valve between the intermediate, PA, and AT positions.

[0041] When the proportional valve switches between the intermediate working position, the PA working position, and the AT working position, in the intermediate working position, the return liquid flow channel and the liquid inlet flow channel are closed, and the return liquid T port 2.1, the liquid inlet P port 2.2, and the load end A port 3.1 are not connected to each other; in the PA working position, the return liquid flow channel is closed, the liquid inlet flow channel is connected, and the liquid inlet P port 2.2 and the load end A port 3.1 are connected; in the AT working position, the return liquid flow channel is connected, the liquid inlet flow channel is closed, and the return liquid T port 2.1 and the load end A port 3.1 are connected.

[0042] The dual-proportional high-water-base proportional valve also includes a load spring 4 positioned within the inner cavity of the load valve core 5, as well as a return spring 9 and a valve seat return spring 10 positioned within the inner cavity of the return valve core 8. The two ends of the load spring 4 respectively abut the inner end surface of the right end of the housing and the inner end surface of the left end of the load valve core 5; the two ends of the return spring 9 respectively abut the inner end surface of the left end of the housing and the inner end surface of the right end of the return valve core 8; and the two ends of the valve seat return spring 10 respectively abut the inner end surface of the left end of the housing and the outer end surface of the left end of the valve seat 7. In the intermediate operating position, the load spring 4, return spring 9, and valve seat return spring 10 are all compressed.

[0043] Specifically, the housing is primarily composed of a left end cap 1, an outer shell 2, and a right end cap 3, all sealed together. The left side of the outer shell 2 houses the liquid return function assembly (primarily composed of a liquid return valve core 8), which has a liquid return T port 2.1 defined thereon and is limited and sealed by the left end cap 1. The right side houses the liquid inlet function assembly (primarily composed of a load valve core 5, a valve sleeve 6, and a valve seat 7), which has a liquid inlet P port 2.2, a left control chamber K1 port 2.3, and a right control chamber K2 port 2.4 defined thereon, all limited and sealed by the right end cap 3. The right end cap 3 has a load port A port 3.1 defined thereon. The two ends of the load spring 4 respectively abut the left side of the right end cap 3 and the inner end face of the left end of the load valve core 5; the two ends of the liquid return spring 9 respectively abut the right side of the left end cap 1 and the inner end face of the right end of the liquid return valve core 8; and the two ends of the valve seat return spring 10 respectively abut the right side of the left end cap 1 and the outer end face of the left end of the valve seat 7.

[0044] Specifically, the valve seat 7 is mainly composed of a left working section, a middle working section, and a right working section, each of which has an outer diameter that increases in sequence. The right end surface of the right working section and the left end surface of the load valve core 5 form a liquid inlet channel on the left side of the liquid inlet P port 2.2. A flange is provided at the left end of the right working section. The flange is slidably arranged in the annular limiting cavity, and the outer circumference of the flange is in clearance with the inner circumference of the annular limiting cavity. Figure 3 As shown, the annular limiting cavity is primarily enclosed by the outer wall of the valve seat 7 and the stepped groove on the inner wall of the valve sleeve 6. A through-hole is provided on the inner wall of the stepped groove bottom, connecting the annular limiting cavity to the liquid inlet P port 2.2. The outer wall of the middle working section forms a sliding seal with the housing or the inner wall of the valve sleeve 6. The left working section extends into the interior of the liquid return valve core 8 and is in sliding and sealing connection with it. The left outer end surface of the left working section serves as a support surface for the valve seat return spring 10.

[0045] In a specific implementation, the right outer end face of the right working section and the left outer end face of the load valve core 5 are both provided with conical surfaces. When the liquid inlet channel is closed, the two conical surfaces are sealed and fitted together. When the liquid inlet channel is open, the two conical surfaces are spaced apart.

[0046] Specifically, the right end face of the liquid return valve core 8 and the left side face of the shoulder on the inner side of the housing form a liquid return channel on the right side of the liquid return T-port 2.1. The center of the right end face of the liquid return valve core 8 extends axially toward the right, forming an extension portion with a smaller diameter than the main body of the liquid return valve core 8. The extension portion of the liquid return valve core 8 is mounted on the outer side of the left working section of the valve seat 7. The extension portion of the liquid return valve core 8 and the left working section of the valve seat 7 are connected in a sliding and sealing manner. A liquid return cavity is formed between the extension portion of the liquid return valve core 8 and the inner wall of the housing. The liquid return cavity is located to the right of the liquid return T-port 2.1 and is connected to the liquid return T-port 2.1 through the liquid return channel. A number of through holes evenly distributed along the circumference are opened on the end face of the middle working section of the valve seat 7, so that the liquid return cavity is connected to the inner cavity of the valve seat 7.

[0047] Furthermore, the intermediate working section of valve seat 7 and the extended portion of liquid return valve core 8 are spaced apart, creating a dead zone, or transition distance, between valve seat 7 and liquid return valve core 8. This dead zone ensures that the PA and AT operating positions do not affect each other. Specifically, the load valve core 5 and valve seat 7 move leftward together, crossing the dead zone before contacting the liquid return valve core 8.

[0048] Furthermore, the right end face of the return liquid valve core 8 and the left side face of the shoulder inside the shell are both provided with conical surfaces. When the return liquid flow channel is closed, the two conical surfaces are sealed and fitted together; when the return liquid flow channel is closed, the two conical surfaces are spaced apart.

[0049] Specifically, the center of the left end face of the load valve core 5 extends axially toward the left, forming an extension portion with a smaller diameter than the main body of the load valve core 5. The extension portion of the load valve core 5 extends into the inner cavity of the valve seat 7, specifically the inner cavity of the middle working section and the right working section of the valve seat 7. The outer peripheral surface of the extension portion of the load valve core 5 is clearance-matched with the inner peripheral surface of the valve seat 7, and a certain small gap is maintained between the outer end face on the left side of the extension portion of the load valve core 5 and the inner end face of the middle working section of the valve seat 7. A plurality of first connecting holes are provided around the outer periphery of the extension portion of the load valve core 5, and a second connecting hole is provided at the center of the left end face, so that the inner cavity of the load valve core 5 is connected to the inner cavity of the valve seat 7. In a specific implementation, the first connecting holes are all provided radially, and the second connecting holes are provided axially.

[0050] Furthermore, the outer circumference of the valve sleeve 6 is formed with a first annular groove and a second annular groove. The first and second annular grooves communicate with the left control chamber K1 port 2.3 and the right control chamber K2 port 2.4, respectively, on the housing 2. A third annular groove is formed on the inner wall of the valve sleeve 6. The third annular groove and the load valve core 5 form an annular control chamber surrounding the load valve core 5. The width of the third annular groove is greater than the distance between the left control chamber K1 port 2.3 and the right control chamber K2 port 2.4. The bottom inner wall of the first annular groove is formed with a plurality of circumferentially evenly distributed through holes, connecting the left control chamber K1 port 2.3, the first annular groove, and the left control chamber of the annular control chambers. The bottom inner wall of the second annular groove is formed with a plurality of circumferentially evenly distributed through holes, connecting the right control chamber K2 port 2.4, the second annular groove, and the right control chamber of the annular control chambers.

[0051] Furthermore, a fourth annular groove is provided on the outer periphery of the valve sleeve 6, which is connected to the liquid inlet P port 2.2. A plurality of through holes evenly distributed along the circumferential direction are provided on the inner wall of the bottom of the fourth annular groove, so that the liquid inlet P port 2.2, the fourth annular groove and the liquid inlet channel are connected.

[0052] Furthermore, there is always a gap between the liquid return valve core 8 and the inner wall surface of the left end of the housing; there is always a gap between the load valve core 5 and the inner wall surface of the right end of the housing.

[0053] A second aspect of the present invention provides a control method for a dual-proportional high-water-base proportional valve.

[0054] The specific control methods are:

[0055] like Figure 1 As shown, the pressures in the left and right control chambers are maintained equal or neutral, so that the annular control protrusion is located in the center of the annular control chamber. At this point, liquid enters the annular limiting chamber from liquid inlet port P 2.2. The valve seat 7 is subjected to the rightward pressure from liquid inlet port P 2.2 and the rightward force of the valve seat return spring 10, causing the flange on the right working section of the valve seat 7 to abut against the right side wall of the annular limiting chamber, pressing the valve seat 7 tightly against the valve sleeve 6. Simultaneously, the load valve core 5, acting under the leftward force of the load spring 4, is also pressed against the valve seat 7. The right end face of the right working section of the valve seat 7 seals against the left end face of the load valve core 5, closing the liquid inlet passage. Under the action of the liquid return spring 9, the liquid return valve core 8 is pressed tightly against the housing 2, so that the right end face of the liquid return valve core 8 is sealed against the left side face of the shoulder inside the housing, closing the liquid return flow channel and placing the proportional valve in the middle working position. At this time, the liquid return T port 2.1, the liquid inlet P port 2.2 and the load end A port 3.1 of the high water base proportional valve are not connected to each other.

[0056] like Figure 2As shown, the liquid pressure in the left control chamber increases, making it greater than that in the right control chamber. The pressure difference between the left and right control chambers is greater than the elastic force of the load spring 4 on the load valve core 5, pushing the load valve core 5 to the right. Because the valve seat 7 is restrained by the valve sleeve 6, the right end face of the right working section of the valve seat 7 separates from the left end face of the load valve core 5. The inlet flow path is open, connecting the liquid inlet port 2.2, the fourth annular groove, the liquid inlet flow path, the inner cavity of the valve seat 7, the inner cavity of the load valve core 5, and the load end A port 3.1. This causes the proportional valve to switch to the PA working position, connecting the liquid inlet port 2.2 and the load end A port 3.1. By controlling the pressure at the left control chamber K1 port 2.3, the opening between the load valve core 5 and the valve seat 7 is controlled proportionally. In the PA working position, the pressure at the left control chamber K1 port 2.3 is adjusted according to the target flow rate until the flow rate outflowing from the load end A port 3.1 reaches the target flow rate.

[0057] like Figure 4 As shown, the liquid pressure in the right control chamber increases, making the pressure in the left control chamber lower than that in the right control chamber. The pressure difference between the left and right control chambers is greater than the elastic force of the valve seat return spring 10 on the valve seat 7, driving the load valve core 5 and the valve seat 7 to move synchronously to the left. After crossing the dead zone distance, as the pressure at port 2.4 of the right control chamber K2 continues to rise, the pressure difference between the left and right control chambers is greater than the sum of the elastic forces of the return spring 9 and the valve seat return spring 10. That is, the pressure difference simultaneously overcomes the elastic forces of the return spring 9 and the valve seat return spring 10, driving the load valve core 5 and the valve seat 7 and the return valve core 8 to move synchronously to the left. The right end face of the return valve core 8 separates from the left side face of the shoulder inside the housing, the return liquid flow path is connected, and the return liquid port 2.1, the return liquid flow path, the return liquid chamber, the inner cavity of the valve seat 7, the inner cavity of the load valve core 5, and the load end A port 3.1 are connected. As a result, the proportional valve switches to the AT working position, and the return liquid port 2.1 is connected to the load end A port 3.1. By controlling the pressure at port 2.4 of the right control chamber K2, the opening between the return valve core 8 and the housing 2 is proportionally controlled. In the AT operating position, the pressure at port 2.3 of the left control chamber K1 is adjusted according to the target flow rate until the flow rate of liquid outflowing from port 2.1 of the return liquid T reaches the target flow rate.

[0058] The foregoing description is merely a description of the preferred embodiments of the present invention and should not be construed as limiting the scope of the claims. The present invention is not limited to the foregoing embodiments, and variations in the specific structure are permitted. Any variations within the scope of the independent claims of the present invention are also within the scope of protection of the present invention.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

Claims

1. A dual-proportional high water-based proportional valve, characterized by: The dual-proportional high-water-base proportional valve comprises a housing, and a load valve core (5), a valve sleeve (6), a valve seat (7), and a liquid return valve core (8) coaxially arranged inside the housing; the housing is provided with a liquid return T port (2.1), a liquid inlet P port (2.2), a left control chamber K1 port (2.3), a right control chamber K2 port (2.4), and a load end A port (3.1); A liquid return valve core (8) is slidably provided at the left end of the housing, and a valve sleeve (6) is arranged at the right end. A valve seat (7) and a load valve core (5) are slidably arranged in sequence from left to right in the valve sleeve (6); the valve sleeve (6) is fixedly connected to the housing, and the inner cavity of the liquid return valve core (8), the inner cavity of the valve seat (7), the inner cavity of the load valve core (5) and the load end A port (3.1) are in communication. A liquid inlet flow channel is formed between the valve seat (7) and the load valve core (5), and the load valve core (5) slides to open or close the liquid inlet flow channel. The opening of the liquid inlet flow channel causes the liquid inlet port (2.2) to communicate with the inner cavity of the valve seat (7); a liquid return flow channel is formed between the liquid return valve core (8) and the inner wall of the shell. The sliding of the liquid return valve core (8) causes the liquid return flow channel to open or close. The opening of the liquid return flow channel causes the liquid return port (2.1) to communicate with the inner cavity of the valve seat (7); An annular control chamber and an annular control protrusion that slide and seal with each other are provided between the load valve core (5) and the valve sleeve (6). The annular control protrusion divides the annular control chamber into a left control chamber and a right control chamber. The left control chamber is connected to the left control chamber K1 port (2.3), and the right control chamber is connected to the right control chamber K2 port (2.4). The pressure difference between the left control chamber and the right control chamber drives the load valve core (5) to slide, thereby enabling the dual-proportional high-water-base proportional valve to switch between the intermediate working position, the PA working position, and the AT working position, and proportionally control the flow in the PA working position and the AT working position. In the intermediate working position, the return liquid flow channel and the inlet liquid flow channel are closed, and the return liquid T port (2.1), the inlet liquid P port (2.2) and the load end A port (3.1) are not connected to each other; in the PA working position, the return liquid flow channel is closed, the inlet liquid flow channel is connected, and the inlet liquid P port (2.2) and the load end A port (3.1) are connected; in the AT working position, the return liquid flow channel is connected, the inlet liquid flow channel is closed, and the return liquid T port (2.1) and the load end A port (3.1) are connected.

2. A dual-proportional high water-based proportional valve according to claim 1, characterized in that: The dual-proportional high-water-base proportional valve further comprises a load spring (4) arranged in the inner cavity of the load valve core (5), and a liquid return spring (9) and a valve seat reset spring (10) arranged in the inner cavity of the liquid return valve core (8); the two ends of the load spring (4) respectively abut against the inner end surface of the right end of the housing and the inner end surface of the left end of the load valve core (5); the two ends of the liquid return spring (9) respectively abut against the inner end surface of the left end of the housing and the inner end surface of the right end of the liquid return valve core (8); and the two ends of the valve seat reset spring (10) respectively abut against the inner end surface of the left end of the housing and the outer end surface of the left end of the valve seat (7).

3. A dual-proportional high water-based proportional valve according to claim 2, characterized in that: The valve seat (7) is mainly composed of a left working section, an intermediate working section and a right working section, the outer diameters of which increase in sequence. The right working section and the load valve core (5) form a liquid inlet channel on the left side of the liquid inlet P port (2.2). The right working section is provided with a flange, which is slidably arranged in an annular limiting cavity. The annular limiting cavity is mainly enclosed by the outer wall of the valve seat (7) and the stepped groove on the inner wall of the valve sleeve (6). A through hole is provided on the inner wall of the groove bottom of the stepped groove, so that the annular limiting cavity is connected with the liquid inlet P port (2.2). The outer wall surface of the intermediate working section is in sliding sealing cooperation with the inner wall surface of the housing or the valve sleeve (6). The left working section extends into the liquid return valve core (8) and is connected to the liquid return valve core (8) in a sliding sealing manner. The outer end surface of the left working section serves as a support surface for the valve seat reset spring (10).

4. A dual-proportional high water-based proportional valve according to claim 3, characterized in that: The liquid return valve core (8) and the shoulder on the inner side of the shell form a liquid return flow channel on the right side of the liquid return T port (2.1). The center of the right end surface of the liquid return valve core (8) extends axially toward the right side to form an extension portion with a smaller diameter. The extension portion of the liquid return valve core (8) is sleeved on the outer side of the left working section of the valve seat (7), and the middle working section of the valve seat (7) and the extension portion of the liquid return valve core (8) are arranged at intervals. A liquid return cavity is formed between the extension portion of the liquid return valve core (8) and the inner wall of the shell. The liquid return cavity is connected to the liquid return T port (2.1) through the liquid return flow channel. A plurality of through holes are provided on the end surface of the middle working section of the valve seat (7), so that the liquid return cavity is connected to the inner cavity of the valve seat (7).

5. The dual-proportional high water-based proportional valve according to claim 2, characterized in that: The center of the left end surface of the load valve core (5) extends axially toward the left side to form an extension portion with a smaller diameter, and the extension portion of the load valve core (5) extends into the inner cavity of the valve seat (7); a plurality of first connecting holes are formed around the outer circumference of the extension portion of the load valve core (5), and a second connecting hole is formed on the left end surface, so that the inner cavity of the load valve core (5) is connected to the inner cavity of the valve seat (7).

6. The dual-proportional high water-based proportional valve according to claim 1, characterized in that: The outer circumference of the valve sleeve (6) is provided with a first annular groove and a second annular groove, the first annular groove and the second annular groove being in communication with the left control chamber K1 port (2.3) and the right control chamber K2 port (2.4) respectively; the inner wall of the valve sleeve (6) is provided with a third annular groove, the third annular groove and the load valve core (5) forming an annular control chamber; the inner wall of the bottom of the first annular groove is provided with a plurality of circumferentially distributed through holes, so that the left control chamber K1 port (2.3), the first annular groove and the left control chamber in the annular control chamber are in communication; the inner wall of the bottom of the second annular groove is provided with a plurality of circumferentially distributed through holes, so that the right control chamber K2 port (2.4), the second annular groove and the right control chamber in the annular control chamber are in communication.

7. The dual-proportional high water-based proportional valve according to claim 1, characterized in that: A fourth annular groove is provided on the outer periphery of the valve sleeve (6), the fourth annular groove being in communication with the liquid inlet P port (2.2), and a plurality of circumferentially distributed through holes are provided on the inner wall of the bottom of the fourth annular groove, so that the liquid inlet P port (2.2), the fourth annular groove and the liquid inlet flow channel are in communication.

8. The dual-proportional high water-based proportional valve according to claim 1, characterized in that: The housing is mainly formed by sealingly connecting a left end cover (1), an outer shell (2) and a right end cover (3).

9. The dual-proportional high water-based proportional valve according to claim 1, characterized in that: There is always a gap between the liquid return valve core (8) and the inner wall surface of the left end of the housing; there is always a gap between the load valve core (5) and the inner wall surface of the right end of the housing.

10. A control method using the dual-proportional high water-base proportional valve according to any one of claims 1 to 9, characterized in that: The pressures in the left control chamber and the right control chamber are kept the same or are pressure-free, so that the annular control protrusion is located in the center of the annular control chamber, the flange on the right working section of the valve seat (7) abuts against the right side wall of the annular limit chamber, the right end face of the right working section of the valve seat (7) is sealed against the left end face of the load valve core (5), the liquid inlet flow channel is closed, the right end face of the liquid return valve core (8) is sealed against the left side face of the shoulder inside the housing, the liquid return flow channel is closed, and the proportional valve is in the middle working position, and the liquid return T port (2.1), the liquid inlet P port (2.2) and the load end A port (3.1) are not connected to each other; The liquid pressure in the left control chamber is increased so that the pressure in the left control chamber is greater than the pressure in the right control chamber. The pressure difference between the left control chamber and the right control chamber overcomes the elastic force of the load spring (4) on the load valve core (5), driving the load valve core (5) to move rightward. The right end surface of the right working section of the valve seat (7) is separated from the left end surface of the load valve core (5). The liquid inlet flow channel is connected, and the liquid inlet P port (2.2), the liquid inlet flow channel, the inner cavity of the valve seat (7), the inner cavity of the load valve core (5) and the load end A port (3.1) are connected, thereby switching the proportional valve to the PA working position, and the liquid inlet P port (2.2) and the load end A port (3.1) are connected. In the PA working position, the pressure of the left control chamber K1 port (2.3) is adjusted according to the target flow rate until the flow rate of the liquid flowing out of the load end A port (3.1) reaches the target flow rate. The liquid pressure in the right control chamber is increased, so that the pressure in the left control chamber is lower than that in the right control chamber. The pressure difference between the left control chamber and the right control chamber overcomes the elastic force of the valve seat return spring (10) on the valve seat (7), drives the load valve core (5) to drive the valve seat (7) to move synchronously to the left. The pressure difference between the left control chamber and the right control chamber overcomes the elastic force of the return spring (9) and the valve seat return spring (10), drives the load valve core (5) to drive the valve seat (7) and the return valve core (8) to move synchronously to the left, so that the right end of the return valve core (8) The surface is separated from the left side of the shoulder on the inner side of the shell, the return liquid flow channel is connected, the return liquid T port (2.1), the return liquid flow channel, the return liquid cavity, the inner cavity of the valve seat (7), the inner cavity of the load valve core (5) and the load end A port (3.1) are connected, and then the proportional valve is switched to the AT working position, and the return liquid T port (2.1) and the load end A port (3.1) are connected; in the AT working position, the pressure of the left control chamber K1 port (2.3) is adjusted according to the target flow until the flow rate of the liquid flowing out of the return liquid T port (2.1) reaches the target flow rate.

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