Pressure regulating system and its pressure regulating method

Abstract

The present invention discloses a pressure regulating system and a pressure regulating method thereof. The pressure regulating system includes: a pilot-operated two-way three-way valve and a pressure sensor connected to the pressure control chamber of the pressure working component. The pilot-operated two-way three-way valve includes a pilot valve disposed on one side of the valve seat and a main valve disposed on the other side of the valve seat. The pressure sensor and the coil assembly of the pilot valve are electrically connected to the electronic control unit respectively. The pressure regulating method of the present invention can not only achieve the state where port A is connected to port P and the state where port A is connected to port T, but also achieve the state where port A is not connected to both port P and port T during the pressure holding stage. The coil assembly is switched on and off at a set frequency to control the reciprocating movement of the main spool, dynamically regulate the pressure of port A, and keep the pressure of the pressure control chamber connected to port A in the system stable, meeting the working requirements; and simplify the structure and reduce the cost.

Description

Technical Field

[0001] The present invention relates to the technical field of fluid pressure control, and particularly to a pressure regulating system and a pressure regulating method for the pressure regulating system. Background Art

[0002] Controlling and adjusting the pressure of the fluid in a closed cavity is a frequently used technique in the fluid field.

[0003] In a Chinese invention patent with the publication number CN106678426A and the name "Hydraulically Driven Gas Injection Valve", an oil inlet solenoid valve and an oil outlet solenoid valve are provided. By controlling the opening of the oil inlet solenoid valve, high-pressure hydraulic oil can enter the valve body cavity, and the hydraulic oil pressure in the valve body cavity increases. By controlling the opening of the oil outlet solenoid valve, the hydraulic oil in the valve body cavity can flow out of the valve body cavity and back to the fuel tank, and the hydraulic oil pressure in the valve body cavity decreases. The hydraulic oil in the valve body cavity generates a thrust on the valve core, overcoming the spring force to push the valve core to move and open. After reaching equilibrium with the return spring force, the valve core stops moving, and the position sensor detects the position of the valve core and feeds back, so as to precisely control the opening of the valve core.

[0004] The problems existing in the above patent are that two solenoid valves are used to control the hydraulic oil pressure in the valve body cavity, resulting in a complex structure and high cost. Therefore, simplifying the structure and reducing the cost have become problems that need to be further solved in the above patent. If a single valve can achieve the functions of the two solenoid valves in the above patent, the problems of complex structure and high cost can be solved to a certain extent.

[0005] In the prior art, a traditional two-way three-way valve is provided with a P port, an A port, and a T port. The P port is used to connect to high-pressure fluid, the T port is used to connect to low-pressure fluid, and the A port is used as a working port. It can only achieve two states: the A port is connected to the P port and the A port is connected to the T port, and it cannot achieve the state where the A port is not connected to both the P port and the T port, so that the pressure in the working cavity connected to the A port in the system cannot be maintained. Therefore, using a traditional two-way three-way valve cannot solve the problems existing in the above CN106678426A patent.

[0006] Therefore, how to improve the traditional two-way three-way valve so that it can achieve the state where the A port is connected to the P port, the state where the A port is connected to the T port, and the state where the A port is not connected to both the P port and the T port has become an urgent technical problem to be solved. Summary of the Invention

[0007] In view of this, the technical problem to be solved by the present invention is: to provide a pressure regulating system and a pressure regulating method for the pressure regulating system, which use a new type of two-way three-way valve to achieve both the state where the A port is connected to the P port, the state where the A port is connected to the T port, and the state where the A port is not connected to both the P port and the T port, so as to maintain the pressure in the working cavity connected to the A port in the system stable, meet the working requirements, and simplify the structure and reduce the cost.

[0008] To solve the above technical problems regarding the pressure regulating system, the technical solution of the present invention is as follows: a pressure regulating system, which includes: a pressure working component having a pressure control chamber connected to a pressure regulating valve. A pressure sensor is provided in the pressure control chamber, and the pressure sensor and the pressure regulating valve are electrically connected to an electronic control unit respectively; the pressure regulating valve is a pilot-operated two-position three-way valve, which includes a valve seat, a pilot valve provided on one side of the valve seat, and a main valve provided on the other side of the valve seat.

[0009] The main valve includes a valve body, a main spool, and a return spring. The valve body is fixedly connected to the valve seat. The valve body is provided with a P port, an A port, and a T port that communicate with the inner cavity of the valve body and are axially spaced apart. The P port communicates with high-pressure fluid, the T port communicates with low-pressure fluid, and the A port communicates with the pressure control chamber; the main spool is slidably disposed in the inner cavity of the valve body, and the main spool is provided with a spool flow channel A, a spool flow channel P, a throttle hole A, and a throttle hole P; the return spring is sandwiched between an end cover and the main spool. The end cover is installed at the end of the inner cavity of the valve body. A chamber A is formed among the end cover, the valve body, and the main spool. The chamber A communicates with the A port through the spool flow channel A and the throttle hole A.

[0010] The pilot valve includes a coil assembly, an armature assembly, and a pilot spool. The coil assembly is fixedly connected to the valve seat and is electrically connected to the electronic control unit. A guide sleeve is provided in the center of the coil assembly; the armature assembly includes a static armature and a moving armature coaxially arranged. The static armature is fixedly connected to the valve seat. The static armature is provided with a central through hole of the static armature. The moving armature is slidably disposed in the guide sleeve and is connected to one end of the pilot spool. The pilot spool is slidably disposed in the central through hole of the static armature. The other end of the pilot spool is provided with an end cone surface. A sealing structure for forming a sealing cone surface in cooperation with the end cone surface is provided in the central through hole of the static armature; a chamber P is formed among the main spool, the valve body, the static armature, the sealing structure, and the pilot spool. The chamber P communicates with the P port through the throttle hole P and the spool flow channel P; a pressure relief structure is provided in the chamber P.

[0011] Among them, the pressure relief structure includes: a valve body diversion groove provided on the outer peripheral surface of the valve body, and a static armature pressure relief hole provided in the static armature and communicating with the central through hole of the static armature; when the chamber P is depressurized, the fluid connects the chamber P, the central through hole of the static armature, the static armature pressure relief hole, the valve body diversion groove, and the T port.

[0012] Among them, the pilot-operated two-position three-way valve is further provided with a moving armature pressure balance structure communicated with the T port. The moving armature pressure balance structure includes: a static armature guide groove provided on the outer peripheral surface of the static armature, a moving armature guide surface provided on the outer peripheral surface of the moving armature, and a moving armature guide flow channel provided in the moving armature.

[0013] Among them, the moving armature is arranged as a cylinder, and a planar structure is provided on the outer peripheral surface of the cylinder. The planar structure serves as the moving armature guide surface; the moving armature guide flow channel includes a moving armature axial flow channel and a moving armature radial flow channel that are communicated with each other.

[0014] Among them, one end of the central through hole of the static armature is provided with an enlarged diameter section, and the sealing structure is arranged as a sealing seat sleeve, and the sealing seat sleeve is embedded in the enlarged diameter section.

[0015] Among them, along the direction from the P port to the chamber P, the radial dimension of the valve core flow channel P increases sequentially. A valve core insert is provided in the large diameter section of the valve core flow channel P, and the throttle hole P is arranged in the valve core insert.

[0016] Among them, the guide sleeve is a non-magnetic guide sleeve, one end of the guide sleeve is closed, and the other end is open.

[0017] To solve the above technical problems regarding the pressure regulating method of the pressure regulating system, the technical solution of the present invention is as follows: In the pressure regulating method of the pressure regulating system, the rated pressure of the high-pressure fluid is set as P0, the target pressure of the pressure control chamber is P1, P1 < P0, the target pressure deviation is △P, △P > 0, and the actually measured pressure of the pressure sensor is P. The pressure regulating method is as follows:

[0018] S10. Initial stage: The coil assembly is powered off, and the A port is communicated with the T port;

[0019] S20. Boosting stage: The coil assembly is powered on, the main valve core moves to the left, the chamber A becomes smaller, the A port is disconnected from the T port, the A port is communicated with the P port, and the pressure of the A port rises;

[0020] S30. Disconnection stage: Before the pressure sensor measures that P rises to P1 and P < P1, the coil assembly is powered off, the chamber P is depressurized, the main valve core moves to the right, the chamber A becomes larger, and before the main valve core moves to the position where the A port starts to be disconnected from the P port, the pressure of the A port continues to rise; when the main valve core continues to move to the position where the A port starts to be disconnected from the P port, P > P1; the main valve core continues to move to the right, the chamber A continues to increase, and the pressure of the A port gradually decreases; when the main valve core continues to move to the position where the A port is completely disconnected from the P port and the T port, P = P1;

[0021] S40. Pressure holding stage: The main spool continues to move to the right, and the pressure at port A continues to decrease. Before P drops to P1 - △P, the coil assembly is energized, the pressure in chamber P increases, the main spool moves to the left, chamber A becomes smaller, and the pressure at port A increases; when P = P1 + △P, the coil assembly is de-energized, the main spool moves to the right, chamber A increases, and the pressure at port A gradually decreases; when P = P1 - △P, the coil assembly is energized; repeat this step to keep the pressure at port A always maintained between P = P1 ± △P.

[0022] Among them, when the target pressure of the pressure control chamber is P2 and P2 < P1; control the coil assembly to be de-energized, chamber P is depressurized, the main spool moves to the right, chamber A becomes larger, port A is connected to port T, and the pressure at port A decreases, P < P1; before the pressure sensor measures that P drops to P2, the coil assembly is energized, chamber P is pressurized, the main spool moves to the left, chamber A becomes smaller, and when the main spool continues to move to the left to the position where port A is completely disconnected from port P and port T, P = P2; then, enter the pressure holding stage to keep the pressure at port A always maintained between P = P2 ± △P.

[0023] Among them, when the target pressure of the pressure control chamber is P3 and P1 < P3 < P0; control the coil assembly to be energized, chamber P is pressurized, the main spool moves to the left, chamber A becomes smaller, port A is connected to port P, and the pressure at port A rises, P > P1; before the pressure sensor measures that P rises to P3, the coil assembly is de-energized, chamber P is depressurized, the main spool moves to the right, chamber A becomes larger, and when the main spool continues to move to the right to the position where port A is completely disconnected from port P and port T, P = P3; then, enter the pressure holding stage to keep the pressure at port A always maintained between P = P3 ± △P.

[0024] After adopting the above technical solution, the beneficial effects of the present invention are as follows:

[0025] Since the pressure regulating system of the present invention includes: a pressure sensor connected to the pressure control chamber of the pressure working component and a pilot-operated two-way three-way valve. The pilot-operated two-way three-way valve includes a pilot valve arranged on one side of the valve seat and a main valve arranged on the other side of the valve seat. The pressure sensor and the coil assembly of the pilot valve are respectively electrically connected to the electronic control unit; the pressure regulating method of the pressure regulating system of the present invention, when the pressure at port A of the main valve rises to within the deviation range of the target pressure, the system is in the pressure holding stage and is in a state where port A is completely disconnected from port P and port T. In this state, the coil assembly is controlled to be energized / de-energized at a set frequency, so as to control the reciprocating movement of the main spool and dynamically adjust the pressure at port A to keep the actual pressure at port A always maintained within the deviation range of the target pressure.

[0026] The present invention uses a new type of two-position three-way valve, namely a pilot-operated two-position three-way valve. When the coil assembly is continuously energized, the state of port A communicating with port P can be achieved; when the coil assembly is continuously de-energized, the state of port A communicating with port T can be achieved; when the coil assembly is energized and de-energized at a set frequency, the state where port A is completely disconnected from both port P and port T can be achieved, so that the pressure in the working chamber connected to port A in the system remains basically unchanged, meeting the working requirements. Moreover, in the present invention, a pilot-operated two-position three-way valve realizes the functions of two solenoid valves in the prior art, simplifies the structure, and reduces the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic structural diagram of the pressure regulating system according to an embodiment of the present invention;

[0028] Figure 2 is Figure 1 a schematic diagram of the state where port A of the pilot-operated two-position three-way valve in

[0029] Figure 3 is Figure 1 a schematic diagram of the state where port A of the pilot-operated two-position three-way valve in

[0030] Figure 3.1 is Figure 3 a schematic diagram of the state where port A of the pilot-operated two-position three-way valve in

[0031] Figure 4 is Figure 1 a schematic diagram of the state where port A of the pilot-operated two-position three-way valve in

[0032] Figure 5 is Figure 4 a schematic diagram of the state where port A of the pilot-operated two-position three-way valve in

[0033] In the figure: 100, pilot-operated two-position three-way valve; 200, pressure working component; 2001, pressure control chamber; 300, pressure sensor; 400, electronic control unit;

[0034] 1, valve seat; 2, main valve; 21, valve body; 211, valve body diversion groove; 22, main spool; 221, spool flow channel A; 222, throttle hole A; 223, spool flow channel P; 224, throttle hole P; 225, spool insert; 23, return spring; 24, end cap; 3, pilot valve; 31, coil assembly; 32, guide sleeve; 33, static armature; 331, static armature pressure relief hole; 332, static armature diversion groove; 34, sealing seat sleeve; 35, moving armature; 351, moving armature diversion surface; 352, moving armature axial flow channel; 353, moving armature radial flow channel; 36, pilot spool; a, chamber A; p, chamber P. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The present invention will be further described in detail and non - restrictively below in conjunction with the accompanying drawings and embodiments.

[0036] Embodiment 1

[0037] As Figure 1 shown, the pressure regulation system of the embodiment of the present invention includes: a pressure working component 200, the pressure working component 200 has a pressure control cavity 2001, a pressure sensor 300 is arranged in the pressure control cavity 2001, and the pressure sensor 300 is electrically connected to an electronic control unit 400; it further includes a pressure regulating valve connected to the pressure control cavity 2001, and this pressure regulating valve is a pilot - operated two - position three - way valve 100, and the pilot - operated two - position three - way valve 100 is electrically connected to the electronic control unit 400.

[0038] As Figure 1 shown, among them, the pilot - operated two - position three - way valve 100 includes a valve seat 1, a main valve 2 arranged on one side of the valve seat 1, and a pilot valve 3 arranged on the other side of the valve seat 1.

[0039] Among them, the main valve 2 includes: a valve body 21, a main valve core 22, and a return spring 23. The valve body 21 is fixedly connected to the valve seat 1, and the valve body 21 is provided with a P port, an A port, and a T port that are communicated with the valve inner cavity and are axially spaced. The P port is communicated with high - pressure fluid, the T port is communicated with low - pressure fluid (such as a return oil tank), and the A port is communicated with the pressure control cavity 2001. The main valve core 22 is slidably arranged in the valve inner cavity, and the main valve core 22 is provided with a valve core flow passage A221, a valve core flow passage P223, a throttle hole A222, and a throttle hole P224. The valve core flow passage A221 is not communicated with the valve core flow passage P223; the optimized design is that along the direction from the P port to the cavity Pp, the radial dimension of the valve core flow passage P223 increases successively, a valve core insert 225 is arranged in the large - diameter section of the valve core flow passage P223, and the throttle hole P224 is arranged in the valve core insert 225; the throttle hole A222 and the throttle hole P224 can reduce the fluid flow rate, make the fluid flow slowly, and reduce the impact of the reciprocating movement of the main valve core 22. The return spring 23 is clamped between the end cover 24 and the left end of the main valve core 22. The end cover 24 is installed at the end of the valve inner cavity, and a cavity Aa is formed among the end cover 24, the valve body 21, and the left end of the main valve core 22. The cavity Aa is communicated with the A port of the valve body 21 through the valve core flow passage A221 and the throttle hole A222.

[0040] Among them, the pilot valve 3 includes: a coil assembly 31, an armature assembly, and a pilot valve core 36. The coil assembly 31 is fixedly connected to the valve seat 1 and electrically connected to the electronic control unit 400. A guide sleeve 32 is arranged at the center of the coil assembly 31, and the guide sleeve 32 is a non-magnetic guide sleeve, such as non-magnetic stainless steel, copper, aluminum and other materials. One end of the guide sleeve 32 is closed and the other end is open. The armature assembly includes a static armature 33 and a moving armature 35 coaxially. The static armature 33 is fixedly connected to the valve seat 1. The static armature 33 is provided with a central through hole of the static armature. The moving armature is slidably arranged in the guide sleeve 32 and connected to one end of the pilot valve core 36. The pilot valve core 36 is slidably arranged in the central through hole of the static armature. The left end of the pilot valve core 36 is provided with an end cone surface. The central through hole of the static armature is provided with a sealing structure that cooperates with the end cone surface to form a sealing cone surface. The sealing structure is optimized to be a sealing seat sleeve 34. The left end of the central through hole of the static armature is optimized to be an enlarged diameter section. The sealing seat sleeve 34 is embedded in the enlarged diameter section. The sealing seat sleeve 34 is easy to replace after wear, which can ensure the sealing reliability. A cavity Pp is formed between the right end of the main valve core 22, the valve body 21, the static armature 33, the sealing seat sleeve 34, and the left end of the pilot valve core 36. The cavity Pp is communicated with the P port of the valve body 21 through a throttle hole P224 and a valve core flow channel P223.

[0041] Among them, the cavity Pp is provided with a pressure relief structure. The pressure relief structure includes: a valve body diversion groove 211 arranged on the outer peripheral surface of the valve body 21, and a static armature pressure relief hole 331 arranged in the static armature 33 and communicating with the central through hole of the static armature; when the cavity Pp is pressure-relieved, the fluid communicates the cavity Pp, the central through hole of the static armature, the static armature pressure relief hole 331, the valve body diversion groove 211 with the T port of the valve body 21.

[0042] Among them, in order to release the pressure generated by the movement of the moving armature 35 on the hydraulic oil and reduce the movement resistance of the moving armature 35, the pilot two-way three-way valve 100 is further provided with a moving armature pressure balance structure communicated with the T port. The moving armature pressure balance structure includes: a static armature diversion groove 332 arranged on the outer peripheral surface of the static armature 33, a moving armature diversion surface 351 arranged on the outer peripheral surface of the moving armature 35, and a moving armature diversion flow channel arranged in the moving armature 35. Among them, the moving armature diversion flow channel includes a moving armature axial flow channel 352 and a moving armature radial flow channel 353 that are communicated with each other; it is optimized that the moving armature 35 is set as a cylinder, and a flat structure is arranged on the outer peripheral surface of the cylinder, and this flat structure is used as the moving armature diversion surface 351.

[0043] Embodiment 2

[0044] In the method for regulating the pressure of the pressure regulating system according to the first embodiment of the present invention described above, the rated pressure of the high-pressure fluid is set as P0 (for example, 3 MPa), the target pressure of the pressure control chamber 2001 is P1 (for example, 2 MPa), P1 < P0, the target pressure deviation is ΔP, ΔP > 0 (for example, 0.05 MPa), and the magnitude of ΔP can be determined through experiments. The measured pressure of the pressure sensor 300 is P. The pressure regulating method of this embodiment is as follows:

[0045] S10. Initial stage: As Figure 2 shown, when the electronic control unit 400 controls the coil assembly 31 to be powered off for a long time, under the action of the return spring 23, the main spool 22 is at the rightmost end, and port A is communicated with port T;

[0046] S20. Boosting stage: The electronic control unit 400 controls the coil assembly 31 to be powered on to close the sealing cone surface. The hydraulic oil at port P flows through the spool flow passage P223 and the throttle hole P224 to the chamber Pp, pushing the main spool 22 to overcome the action of the return spring 23. The main spool 22 moves to the left. The hydraulic oil in the chamber Aa is discharged to port A through the spool flow passage A221 and the throttle hole A222. The chamber Aa becomes smaller, port A is disconnected from port T, and port A is communicated with port P. The pressure at port A rises, as Figure 3 shown;

[0047] S30. Disconnection stage: If after the pressure sensor 300 detects that the hydraulic oil pressure in the pressure control chamber 2001 reaches the set target pressure value P1 (this value can be any value between 0 - P0), the electronic control unit 400 controls the coil assembly 31 to be powered off, and the sealing cone surface opens. The hydraulic oil in the chamber Pp is depressurized through the sealing cone surface, and the main spool 22 moves to the right. Before the main spool 22 moves to the position as Figure 3.1 shown, the pressure at port A continues to rise (because port A is still communicated with port P). Therefore, if it is desired to control the pressure at port A to the target pressure P1, it is necessary to control the coil assembly 31 to be powered off in advance;

[0048] In this stage, when the pressure sensor 300 measures that P rises to before P1 (i.e., P < P1), for example, when P = P1 - ΔP1, the electronic control unit 400 controls the coil assembly 31 to be powered off, opens the sealing cone surface, the chamber Pp is depressurized, the main spool 22 moves to the right, the chamber Aa becomes larger, and before the main spool 22 moves to the position where port A starts to be disconnected from port P, the pressure at port A continues to rise; the main spool 22 continues to move to the right to the position where port A starts to be disconnected from port P, as Figure 3.1 shown. At this time, the pressure at port A is slightly higher than the set target pressure (i.e., P > P1), for example, P = P1 + ΔP2; the main spool 22 continues to move to the right, the chamber Aa continues to increase, and the pressure at port A gradually decreases; when the main spool 22 continues to move to the position as Figure 4The position shown. At this time, the A port is completely disconnected from the P port and the T port, and the pressure of the A port drops to the set target pressure, P = P1. In this stage, the magnitudes of △P1 and △P2 are specifically determined by experiments;

[0049] S40. Pressure holding stage: The main spool 22 continues to move to the right, and the pressure of the A port continues to decrease. Before P drops to P1 - △P, the electronic control unit 400 controls the coil assembly 31 to be energized in advance to close the sealing conical surface, the pressure of the Pp chamber increases, the main spool 22 moves to the left, the Aa chamber becomes smaller, and the pressure of the A port increases; When the pressure sensor 300 detects that P = P1 + △P (at this time, the actual position of the main spool 22 may be Figure 3.1 slightly to the right of the position, or slightly to the left due to micro-leakage), the electronic control unit 400 controls the coil assembly 31 to be de-energized to open the sealing conical surface, the main spool 22 moves to the right, the Aa chamber increases, and the pressure of the A port slightly decreases; When the pressure sensor 300 detects that P = P1 - △P, the electronic control unit 400 controls the coil assembly 31 to be energized; Repeat this step to keep the pressure of the A port always maintained between P = P1 ± △P.

[0050] In this stage, the energization / de-energization frequency or time interval of the coil assembly 31 mainly depends on the sizes of the throttle orifice A222 and the throttle orifice P224. The larger the throttle orifice, the faster the flow rate, the shorter the time interval, and the higher the frequency; On the contrary, the smaller the throttle orifice, the slower the flow rate, the longer the time interval, and the lower the frequency; In the present invention, the energization / de-energization frequency of the coil assembly 31 is optimized and designed within the range of several seconds.

[0051] Embodiment 3

[0052] Embodiment 3 is basically the same as Embodiment 2, the difference being that: the target pressure of the pressure control chamber in Embodiment 3 is lower than the target pressure of the pressure control chamber in Embodiment 2. Set the target pressure of the pressure control chamber in Embodiment 3 to P2, and P2 < P1, (for example, P2 is 1.5 MPa), on the Figure 4 basis shown, the adjustment method of Embodiment 3 is as follows:

[0053] The electronic control unit 400 controls the coil assembly 31 to be de-energized to open the sealing conical surface, the Pp chamber is depressurized, the main spool 22 moves to the right, the Aa chamber becomes larger, and when the main spool 22 moves to the right to the Figure 5 position shown, the A port is communicated with the T port, the pressure of the A port decreases, P < P1; Before the pressure sensor 300 measures that P drops to P2, the electronic control unit 400 controls the coil assembly 31 to be energized to close the sealing conical surface, the Pp chamber is pressurized, the main spool 22 moves to the left, the Aa chamber becomes smaller, and when the main spool 22 continues to move to the left to the position where the A port is completely disconnected from the P port and the T port, P = P2, as Figure 4 shown.

[0054] After that, it enters the pressure-holding stage, maintaining the pressure at port A between P = P2 ± ΔP all the time. The principle of the pressure-holding stage in the third embodiment is the same as that in the second embodiment, which will not be elaborated here.

[0055] Embodiment Four

[0056] Embodiment Four is basically the same as Embodiment Two, except that: the target pressure of the pressure control chamber in Embodiment Four is higher than that in Embodiment Two. Set the target pressure of the pressure control chamber in Embodiment Four as P3, and P1 < P3 < P0, (for example, P3 is 2.5 MPa). On the basis of what is shown in Figure 4 the adjustment method of Embodiment Four is as follows:

[0057] The electronic control unit 400 controls the coil assembly 31 to be energized, the chamber Pp is pressurized, the main spool 22 moves to the left, the chamber Aa becomes smaller, and the main spool 22 moves to the left until it reaches the position shown in Figure 3 At this time, port A is connected to port P, and the pressure at port A rises, P > P1; before the pressure sensor 300 measures that P rises to P3, the electronic control unit 400 controls the coil assembly 31 to be de-energized, the chamber Pp is depressurized, the main spool 22 moves to the right, the chamber Aa becomes larger, and when the main spool 22 continues to move to the right until port A is completely disconnected from port P and port T, P = P3, as shown in Figure 4 shown.

[0058] After that, it enters the pressure-holding stage, maintaining the pressure at port A between P = P3 ± ΔP all the time. The principle of the pressure-holding stage in Embodiment Four is the same as that in Embodiment Two, which will not be elaborated here.

[0059] The above takes hydraulic control as an example to introduce the embodiments of the present invention in detail. Obviously, the present invention is not limited to hydraulic control and is also applicable to pneumatic control, which will not be restricted here.

[0060] The present invention uses a pilot-operated two-way three-way valve. When the coil assembly is kept energized, the state of port A communicating with port P can be achieved; when the coil assembly is kept de-energized, the state of port A communicating with port T can be achieved; when the coil assembly is energized / de-energized at a set frequency, the state that port A is completely disconnected from port P and port T can be achieved, so that the pressure of the working chamber connected to port A in the system remains basically unchanged, meeting the working requirements. Moreover, in the present invention, using a pilot-operated two-way three-way valve realizes the functions of two solenoid valves in the prior art, simplifies the system structure, and reduces the cost.

[0061] The above are examples of the preferred embodiments of the present invention. The parts not elaborated in detail are all known technologies in the art. The protection scope of the present invention is subject to the content of the claims, and any equivalent transformation based on the technical inspiration of the present invention is within the protection scope of the present invention.

Claims

1. A pressure regulating system, the pressure regulating system comprising: A pressure working component, the pressure working component having a pressure control chamber, the pressure control chamber being connected to a pressure regulating valve, the pressure control chamber being provided with a pressure sensor, the pressure sensor and the pressure regulating valve being electrically connected to an electronic control unit respectively; characterized in that the pressure regulating valve is a pilot-operated two-position three-way valve, and the pilot-operated two-position three-way valve includes a valve seat, a pilot valve arranged on one side of the valve seat, and a main valve arranged on the other side of the valve seat; The main valve includes a valve body, a main valve core, and a return spring. The valve body is fixedly connected to the valve seat. The valve body is provided with a P port, an A port, and a T port that communicate with the inner cavity of the valve body and are axially spaced. The P port communicates with high-pressure fluid, the T port communicates with low-pressure fluid, and the A port communicates with the pressure control chamber. The main valve core is slidably arranged in the inner cavity of the valve body. The main valve core is provided with a valve core flow passage A, a valve core flow passage P, a throttle hole A, and a throttle hole P. The return spring is clamped between the end cover and the main valve core. The end cover is installed at the end of the inner cavity of the valve body. A chamber A is formed among the end cover, the valve body, and the main valve core. The chamber A communicates with the A port through the valve core flow passage A and the throttle hole A; The pilot valve includes a coil assembly, an armature assembly, and a pilot valve core. The coil assembly is fixedly connected to the valve seat and is electrically connected to the electronic control unit. A guide sleeve is arranged at the center of the coil assembly. The armature assembly includes a static armature and a moving armature that are coaxial. The static armature is fixedly connected to the valve seat. The static armature is provided with a central through hole of the static armature. The moving armature is slidably arranged in the guide sleeve and is connected to one end of the pilot valve core. The pilot valve core is slidably arranged in the central through hole of the static armature. The other end of the pilot valve core is provided with an end cone surface. The central through hole of the static armature is provided with a sealing structure that cooperates with the end cone surface to form a sealing cone surface. A chamber P is formed among the main valve core, the valve body, the static armature, the sealing structure, and the pilot valve core. The chamber P communicates with the P port through the throttle hole P and the valve core flow passage P. The chamber P is provided with a pressure relief structure.

2. The pressure regulating system according to claim 1, wherein, The pressure relief structure includes: a valve body diversion groove arranged on the outer peripheral surface of the valve body, and a static armature pressure relief hole arranged in the static armature and communicating with the central through hole of the static armature. When the chamber P is pressure-relieved, the fluid connects the chamber P, the central through hole of the static armature, the static armature pressure relief hole, the valve body diversion groove, and the T port.

3. The pressure regulation system according to claim 2, wherein The pilot-operated two-position three-way valve is further provided with a moving armature pressure balance structure that communicates with the T port. The moving armature pressure balance structure includes: a static armature diversion groove arranged on the outer peripheral surface of the static armature, a moving armature diversion surface arranged on the outer peripheral surface of the moving armature, and a moving armature diversion flow passage arranged in the moving armature.

4. The pressure regulating system according to claim 3, wherein The moving armature is set as a cylinder, and a planar structure is arranged on the outer peripheral surface of the cylinder, and the planar structure serves as the moving armature diversion surface; the moving armature diversion flow passage includes a moving armature axial flow passage and a moving armature radial flow passage that are connected.

5. The pressure regulating system according to claim 1, wherein One end of the central through-hole of the static armature is provided with a diameter-expanded section, and the sealing structure is a sealing seat sleeve which is embedded in the diameter-expanded section.

6. The pressure regulating system according to claim 1, wherein, Along the direction from the P port to the cavity P, the radial dimension of the valve core flow channel P increases successively. A valve core insert is arranged in the large-diameter section of the valve core flow channel P, and the throttle hole P is arranged in the valve core insert.

7. The pressure regulating system according to claim 1, characterized in that, The guide sleeve is a non-magnetic guide sleeve, one end of which is closed and the other end is open.

8. The pressure regulating method of the pressure regulating system according to any one of claims 1 to 7, characterized in that It is assumed that the rated pressure of the high-pressure fluid is P0, the target pressure of the pressure control cavity is P1, P1 < P0, the target pressure deviation is △P, △P > 0, and the measured pressure of the pressure sensor is P. The pressure regulation method is as follows: S10. Initial stage: The coil assembly is powered off, and the A port is communicated with the T port. S20. Boosting stage: The coil assembly is powered on, the main valve core moves leftward, the cavity A becomes smaller, the A port is disconnected from the T port, the A port is communicated with the P port, and the pressure at the A port rises. S30. Disconnection stage: Before the pressure sensor measures that P rises to P1 and P < P1, the coil assembly is powered off, the cavity P is depressurized, the main valve core moves rightward, the cavity A becomes larger, and before the main valve core moves to the position where the A port starts to be disconnected from the P port, the pressure at the A port continues to rise; when the main valve core continues to move rightward to the position where the A port starts to be disconnected from the P port, P > P1; the main valve core continues to move rightward, the cavity A continues to increase, and the pressure at the A port gradually decreases; when the main valve core continues to move rightward to the position where the A port is completely disconnected from the P port and the T port, P = P1. S40. Pressure holding stage: The main valve core continues to move rightward, the pressure at the A port continues to decrease. Before P drops to P1 - △P, the coil assembly is powered on, the pressure in the cavity P rises, the main valve core moves leftward, the cavity A becomes smaller, and the pressure at the A port rises; when P = P1 + △P, the coil assembly is powered off, the main valve core moves rightward, the cavity A increases, and the pressure at the A port gradually decreases; when P = P1 - △P, the coil assembly is powered on; repeat this step to keep the pressure at the A port always maintained between P = P1 ± △P.

9. The pressure regulating method of the pressure regulating system according to claim 8, characterized in that, When the target pressure of the pressure control cavity is P2 and P2 < P1; Control the coil assembly to be powered off, the cavity P is depressurized, the main valve core moves rightward, the cavity A becomes larger, the A port is communicated with the T port, the pressure at the A port decreases, and P < P1; before the pressure sensor measures that P drops to P2, the coil assembly is powered on, the cavity P is pressurized, the main valve core moves leftward, the cavity A becomes smaller, and when the main valve core continues to move leftward to the position where the A port is completely disconnected from the P port and the T port, P = P2. After that, enter the pressure holding stage to keep the pressure at the A port always maintained between P = P2 ± △P.

10. The pressure regulating method of the pressure regulating system according to claim 8, characterized in that, When the target pressure of the pressure control cavity is P3 and P1 < P3 < P0; Control the coil assembly to be powered on, the cavity P is pressurized, the main valve core moves leftward, the cavity A becomes smaller, the A port is communicated with the P port, the pressure at the A port rises, and P > P1; before the pressure sensor measures that P rises to P3, the coil assembly is powered off, the cavity P is depressurized, the main valve core moves rightward, the cavity A becomes larger, and when the main valve core continues to move rightward to the position where the A port is completely disconnected from the P port and the T port, P = P3. After that, enter the pressure holding stage to keep the pressure at the A port always maintained between P = P3 ± △P.

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