Electric control overflow valve group and pressure adjusting method

Abstract

The invention discloses an electric control overflow valve group and a pressure adjusting method.The electric control overflow valve group comprises an overflow valve and an electromagnetic pilot valve, the overflow valve is provided with a first liquid inlet and a first liquid outlet, the first liquid inlet is connected with a liquid source, the first liquid outlet is connected with a liquid return box, and the electromagnetic pilot valve comprises a first reversing valve and a second reversing valve; the first reversing valve has a first working state, the second reversing valve has a second working state, the pressure of the first liquid inlet is increased by controlling the first reversing valve to be switched to the first working state, and the pressure of the first liquid inlet is decreased by controlling the second reversing valve to be switched to the second working state. Remote control of pressure is achieved by discharging liquid into or out of the overflow valve, and adjustment is more accurate, quicker and more convenient; and the pressure is still kept stable and unchanged during power failure.

Description

Technical Field

[0001] The present invention relates to the technical field of valves, and more particularly to an electronically controlled overflow valve group and a pressure regulation method. Background Art

[0002] An overflow valve is a pressure regulating device for a hydraulic system and is widely used in a spray pump station. The pressure of high-pressure water required for dust spraying on a working face is regulated by the overflow valve.

[0003] In the prior art, the pressure regulation mode of the overflow valve is manual regulation to control the system pressure. However, this operation is inconvenient, the set pressure is unstable, and remote regulation cannot be achieved, which does not meet the requirements of the development of intelligent coal mining. Summary of the Invention

[0004] The present invention aims to at least solve the technical problem in the prior art that the manual regulation of the overflow valve cannot achieve precise regulation and remote control.

[0005] To this end, an object of the present invention is to provide an electronically controlled overflow valve group, which includes an overflow valve and an electromagnetic pilot valve. The overflow valve has a first liquid inlet and a first liquid outlet. The first liquid inlet is connected to a liquid source, and the first liquid outlet is connected to a liquid return tank. The electromagnetic pilot valve includes a first reversing valve and a second reversing valve. The first reversing valve has at least a first working state, and the second reversing valve has at least a second working state. By controlling the first reversing valve to switch to the first working state, the pressure of the first liquid inlet is increased, and by controlling the second reversing valve to switch to the second working state, the pressure of the first liquid inlet is decreased.

[0006] In some embodiments, the overflow valve includes an overflow valve body. An overflow valve cavity is provided in the overflow valve body. The first liquid inlet and the first liquid outlet are respectively communicated with the overflow valve cavity. A movable valve core is provided in the overflow valve cavity. The valve core divides the overflow valve cavity into a first valve cavity and a second valve cavity. An elastic member is provided between the valve core and the overflow valve body.

[0007] In some embodiments, the first reversing valve is provided with a second liquid inlet and a first working port. The second liquid inlet is communicated with the first liquid inlet. The first working port is communicated with the first valve cavity. The first reversing valve further includes a third working state. When the first reversing valve switches to the first working state, the first working port is communicated with the second liquid inlet. When the first reversing valve switches to the third working state, the first working port is cut off from the second liquid inlet.

[0008] The second reversing valve is provided with a third liquid inlet and a second working port. The third liquid inlet is communicated with the first valve cavity, and the second working port is communicated with the liquid return tank. The second reversing valve further includes a fourth working state. When the second reversing valve is switched to the second working state, the third liquid inlet is communicated with the second working port. When the second reversing valve is switched to the fourth working state, the third liquid inlet and the second working port are cut off.

[0009] In some embodiments, the first reversing valve is provided with a second liquid outlet, and the second liquid outlet is communicated with the liquid return tank. A first one-way valve is arranged between the first working port and the first valve cavity to enable the liquid to flow unidirectionally along the first reversing valve towards the overflow valve.

[0010] In some embodiments, the second reversing valve is provided with a third liquid outlet, and the third liquid outlet is communicated with the liquid return tank. A second one-way valve is arranged between the second working port and the liquid return tank to enable the liquid to flow unidirectionally along the second working port towards the liquid return tank.

[0011] In some embodiments, the electromagnetic pilot valve further includes a pilot valve body. A control cavity is arranged in the pilot valve body, and the control cavity is communicated with the first valve cavity. A first pressure regulating part and a second pressure regulating part are further arranged in the pilot valve body. The first pressure regulating part and the pilot valve body form a first chamber, and the second pressure regulating part and the pilot valve body form a second chamber. The control cavity is respectively communicated with the first chamber and the second chamber. The first chamber is communicated with the first liquid inlet, and the second chamber is communicated with the first liquid outlet.

[0012] In some embodiments, the electronically controlled overflow valve group further includes an accumulator, and the accumulator is communicated with the control cavity of the electromagnetic pilot valve.

[0013] Another object of the present invention is to propose a pressure regulating method, which is applied to the above-mentioned electronically controlled overflow valve group, and includes:

[0014] Based on a first preset value and a second preset value of the system pressure, determine the set value and the allowable deviation range of the pressure regulation. The first preset value is less than the second preset value, and the set value and the allowable deviation range are respectively between the first preset value and the second preset value, and the set value is within the allowable deviation range;

[0015] Obtain the system pressure value, and the system pressure value is the pressure of the first liquid inlet;

[0016] Based on the magnitude of the system pressure value, determine the adjustment strategy;

[0017] Control the electromagnetic pilot valve based on the adjustment strategy, adjust the pressure in the first valve chamber of the overflow valve, and adjust the system pressure value within the allowable deviation range.

[0018] In some embodiments, determining the adjustment strategy based on the magnitude of the system pressure value includes:

[0019] When the system pressure value is less than a first preset value, determine the adjustment strategy as increasing the pressure in the first valve chamber;

[0020] When the system pressure value is greater than a second preset value, determine the adjustment strategy as decreasing the pressure in the first valve chamber, where the first preset value is less than the second preset value.

[0021] In some embodiments, when determining the adjustment strategy as increasing the pressure in the first valve chamber, the controller sends a pressure increasing signal to the electromagnetic pilot valve, and the first reversing valve of the electromagnetic pilot valve switches to a first working state, so that the first working port of the first reversing valve communicates with the second liquid inlet, and adjusts the system pressure value within the allowable deviation range;

[0022] When determining the adjustment strategy as decreasing the pressure in the first valve chamber, the controller sends a pressure decreasing signal to the electromagnetic pilot valve, and the second reversing valve of the electromagnetic pilot valve switches to a second working state, so that the third liquid inlet of the second reversing valve communicates with the second working port, and adjusts the system pressure value within the allowable deviation range.

[0023] In some embodiments, when determining the adjustment strategy as increasing the pressure in the first valve chamber, adjust the first pressure regulating part to communicate the first chamber with the control chamber, so that the first chamber communicates with the first liquid inlet;

[0024] When determining the adjustment strategy as decreasing the pressure in the first valve chamber, adjust the second pressure regulating part to communicate the second chamber with the control chamber, so that the second chamber communicates with the first liquid outlet.

[0025] An electronically controlled overflow valve group and a pressure adjustment method provided by an embodiment of the present invention have the following beneficial effects:

[0026] By switching the first reversing valve and the second reversing valve of the electromagnetic pilot valve to the first working state or the second working state, discharging or injecting liquid into the overflow valve, thereby increasing or decreasing the pressure at the first liquid inlet, realizing remote control of the overflow valve pressure, with more accurate, fast and convenient adjustment, and realizing pressure adjustment through closed-loop control of the electronic control signal, with high adjustment accuracy; at the same time, a pressure locking function can be realized, and the pressure remains stable when the power is off, ensuring the accuracy of pressure adjustment. Description of the Drawings

[0027] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 is the system schematic diagram of the electronically controlled overflow valve group in the embodiments of the present invention;

[0029] Figure 2 is the three-dimensional view of the electronically controlled overflow valve group in the embodiments of the present invention;

[0030] Figure 3 is the internal structure schematic diagram of the electronically controlled overflow valve group in the embodiments of the present invention;

[0031] Figure 4 is the internal structure schematic diagram of the electronically controlled overflow valve group in the embodiments of the present invention;

[0032] Figure 5 is the step schematic diagram of the pressure regulation method in the embodiments of the present invention.

[0033] Figure 6 is the relationship schematic diagram of the first preset value, the second preset value, the set value, and the allowable deviation range in the pressure regulation method in the embodiments of the present invention.

[0034] Reference numerals:

[0035] 1. Overflow valve; 11. First liquid inlet; 12. First liquid outlet; 13. Overflow valve body; 14. Overflow valve cavity; 141. First valve cavity; 142. Second valve cavity; 15. Spool; 151. Groove; 16. Elastic member; 17. Overflow valve seat; 18. First flow channel; 19. Second flow channel; 2. Electromagnetic pilot valve; 21. Pilot valve body; 22. Control cavity; 23. First reversing valve; 231. Second liquid inlet; 232. Second liquid outlet; 233. First working port; 24. Second reversing valve; 241. Third liquid inlet; 242. Third liquid outlet; 243. Second working port; 25. First pressure regulating part; 26. Second pressure regulating part; 27. First chamber; 28. Second chamber; 29. Third flow channel; 210. Fourth flow channel; 3. Liquid source; 4. Liquid return tank; 5. Accumulator; 6. Pressure detection device; 7. First filter; 8. First check valve; 81. First check valve seat; 82. First check valve core; 83. First through hole; 84. Second through hole; 9. Second check valve. Detailed embodiments

[0036] The various solutions and features of the present invention are described herein with reference to the accompanying drawings.

[0037] It should be understood that various modifications can be made to the embodiments applied herein. Therefore, the above description should not be construed as limiting, but merely as an example of the embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the present invention.

[0038] The accompanying drawings, which are included in and form a part of this specification, illustrate embodiments of the present invention and, together with the general description of the present invention given above and the detailed description of the embodiments given below, serve to explain the principles of the present invention.

[0039] These and other features of the present invention will become apparent from the following description of the preferred forms of the embodiments, given by way of non-limiting example with reference to the accompanying drawings.

[0040] It should also be understood that although the present invention has been described with reference to some specific examples, those skilled in the art can surely implement many other equivalent forms of the present invention, which have the features as described in the claims and thus are all within the protection scope defined thereby.

[0041] When combined with the accompanying drawings, the above and other aspects, features and advantages of the present invention will become more apparent in view of the following detailed description.

[0042] Specific embodiments of the present invention are hereinafter described with reference to the accompanying drawings; however, it should be understood that the embodiments applied are merely examples of the present invention and can be implemented in various ways. Well-known and / or repetitive functions and structures are not described in detail to avoid obscuring the present invention with unnecessary or redundant details. Therefore, the specific structural and functional details applied herein are not intended to be limiting, but merely serve as a basis for the claims and a representative basis for teaching those skilled in the art to use the present invention in substantially any suitable detailed structure in a variety of ways.

[0043] The first embodiment of the present invention provides an electronically controlled overflow valve group, as Figures 1-4 shown, the electronically controlled overflow valve group includes an overflow valve 1 and an electromagnetic pilot valve 2. The overflow valve 1 has a first liquid inlet 11 and a first liquid outlet 12. The first liquid inlet 11 is connected to a liquid source 3, and the first liquid outlet 12 is connected to a liquid return tank 4.

[0044] Specifically, as Figure 3As shown in the figure, the overflow valve 1 includes an overflow valve body 13. An overflow valve chamber 14 is provided inside the overflow valve 1. A movable valve core 15 is provided inside the overflow valve chamber 14. A first liquid inlet 11 and a first liquid outlet 12 are provided on the side of the overflow valve body 13, and the first liquid inlet 11 and the first liquid outlet 12 are respectively communicated with the overflow valve chamber 14. An elastic member 16 is provided between the valve core 15 and the end of the overflow valve body 13 away from the first liquid inlet 11. Taking the vertical setting of the overflow valve 1 as an example for illustration, the valve core 15 divides the overflow valve chamber 14 into a first valve chamber 141 and a second valve chamber 142. Since the valve core 15 can move inside the overflow valve chamber 14 under the combined action of the pressure in the first valve chamber 141 and the pressure in the second valve chamber 142, the valve core 15 can be moved along the overflow valve chamber 14 by changing the pressure in the first valve chamber 141, thereby changing the opening degree between the first liquid inlet 11 and the first liquid outlet 12, and further changing the pressure of the first liquid inlet 11 of the overflow valve 1.

[0045] Further, the electromagnetic pilot valve 2 includes a pilot valve body 21 and a reversing valve. The electromagnetic pilot valve 2 further includes a pilot valve body 21. A control chamber 22 is provided inside the pilot valve body 21, and the control chamber 22 is communicated with the first valve chamber 141. Therefore, by adjusting the pressure in the control chamber 22, the pressure in the first valve chamber 141 can be adjusted accordingly.

[0046] In addition, the electro-control overflow valve group further includes an accumulator 5. The inside of the accumulator 5 has an energy storage chamber, and the energy storage chamber is communicated with the control chamber 22, so that the pressure in the control chamber 22 can be controlled by adjusting the pressure in the energy storage chamber. When the instantaneous pressure in the control chamber 22 increases, the accumulator 5 converts the energy in the pipeline system into compression energy or potential energy and stores it in the energy storage chamber; when the instantaneous pressure in the control chamber 22 decreases, the compression energy or potential energy is converted into hydraulic energy, pneumatic energy, etc. and released, and then re-supplied to the system to play a role in stabilizing the pressure and ensuring the normal pressure of the entire system.

[0047] Among them, as Figure 2 shown, the pilot valve body 21 is installed at one end of the overflow valve body 13, and the reversing valve is installed at the end of the pilot valve body 21 away from the overflow valve body 13. The overflow valve body 13, the pilot valve body 21, and the reversing valve are arranged in sequence along the first direction (the length direction of the overflow valve body 13). This arrangement is beneficial to reducing the thickness of the electro-control overflow valve group to adapt to the installation position with a narrow space in the width direction. Further, the accumulator 5 is arranged at the end of the pilot valve body 21 away from the overflow valve body 13, that is, the accumulator 5 and the reversing valve are arranged on the same side of the pilot valve body 21, which can make reasonable use of the space and reduce the floor area of the electro-hydraulic control overflow valve 1 group.

[0048] A pressure detection device 6 is installed on the pilot valve body 21 to detect the pressure of the first liquid inlet 11 or the pressure of the first valve chamber 141. The pressure detection device 6 and the reversing valve are arranged on the same side of the pilot valve body 21, making reasonable use of the space.

[0049] Further, as Figure 3 shown, a groove 151 is formed at one end of the valve core 15 close to the first chamber 27. One end of the elastic member 16 abuts against the groove 151, and the other end of the elastic member 16 abuts against the pilot valve body 21. Thus, after the valve core 15 moves along the overflow valve chamber 14, the elastic member 16 realizes the reset of the valve core 15. In addition, an overflow valve seat 17 is provided in the overflow valve chamber 14. The overflow valve seat 17 is arranged on the outer periphery of the valve core 15 and abuts against the inner side wall of the overflow valve chamber 14. The overflow valve seat 17 has an inclined surface abutting against the valve core 15. In the initial state, the valve core 15 is pressed against the overflow valve seat 17 under the elastic force of the elastic member 16, and the blockage between the first liquid inlet 11 and the first liquid outlet 12 is realized through the inclined surface.

[0050] Further, a first flow channel 18 and a second flow channel 19 are provided in the overflow valve body 13. The reversing valve includes a first reversing valve 23 and a second reversing valve 24. One end of the first flow channel 18 is communicated with the first liquid inlet 11, and the other end of the first flow channel 18 is communicated with the control chamber 22 through the first reversing valve 23. One end of the second flow channel 19 is communicated with the first liquid outlet 12, and the other end of the second flow channel 19 is communicated with the control chamber 22 through the second reversing valve 24 and the control chamber 22. The first flow channel 18 and the second flow channel 19 here play a damping role, and it is easier to realize the pressure regulation of the control chamber 22.

[0051] Further, a first filter 7 is provided between the first liquid inlet 11 and the second liquid inlet 231. The first filter 7 filters the liquid entering the electro-control overflow valve group from the first liquid inlet 11 to avoid impurities from entering, thereby prolonging the service life of the electro-control overflow valve group.

[0052] Further, in some embodiments, as Figure 1 and Figure 3As shown in the figure, the first reversing valve 23 includes a second liquid inlet 231 and a first working port 233. The second liquid inlet 231 is communicated with the first liquid inlet 11, and the first working port 233 is communicated with the control chamber 22. At this time, the first reversing valve can be understood as a two-position two-way valve. Among them, the first reversing valve 23 has a first working state and a third working state. The electromagnetic pilot valve includes a first electromagnet. By controlling the first reversing valve 23 to switch to the first working state, the pressure of the first liquid inlet 11 can be increased. That is, when the first electromagnet is energized to switch the first reversing valve 23 to the first working state, the first working port 233 is communicated with the second liquid inlet 231. Then, the liquid entering the electro-hydraulic control relief valve group from the first liquid inlet 11 can enter the control chamber 22 through the second liquid inlet 231 and the first working port 233, and then enter the first valve chamber 141, thereby increasing the pressure in the first valve chamber 141. The pressure above the valve core 15 increases, causing the valve core 15 to move downward. The opening between the first liquid inlet 11 and the first liquid outlet 12 decreases, and the pressure of the first liquid inlet 11 increases accordingly. By controlling the power-off of the first electromagnet, the first reversing valve 23 can be switched to the third working state. When the first reversing valve 23 is switched to the third working state, the second liquid inlet 231 and the first working port 233 are cut off.

[0053] In another embodiment, the first reversing valve 23 includes a second liquid inlet 231, a second liquid outlet 232 and a first working port 233. The second liquid inlet 231 is communicated with the first liquid inlet 11, the second liquid outlet 232 is communicated with the liquid return tank 4, and the first working port 233 is communicated with the control chamber 22. At this time, the first reversing valve can be understood as a two-position three-way valve. The first working port 233 and the control chamber 22 are communicated through a first one-way valve 8 to enable the liquid to flow unidirectionally from the first working port 233 to the control chamber 22. Among them, the first reversing valve 23 has a first working state and a third working state. The electromagnetic pilot valve includes a first electromagnet. By controlling the first reversing valve 23 to switch to the first working state, the pressure of the first liquid inlet 11 can be increased. That is, when the first electromagnet is energized to switch the first reversing valve 23 to the first working state, the second liquid inlet 231 and the second liquid outlet 232 are cut off, the second liquid outlet 232 and the first working port 233 are cut off, and the first working port 233 is communicated with the second liquid inlet 231. Then, the liquid entering the electro-hydraulic control relief valve group from the first liquid inlet 11 can enter the control chamber 22 through the second liquid inlet 231, the first working port 233 and the first one-way valve 8, and then enter the first valve chamber 141, thereby increasing the pressure in the first valve chamber 141. The pressure above the valve core 15 increases, causing the valve core 15 to move downward. The opening between the first liquid inlet 11 and the first liquid outlet 12 decreases, and the pressure of the first liquid inlet 11 increases accordingly.

[0054] By controlling the power-off of the first electromagnet, the first reversing valve 23 can be switched to the third working state. When the first reversing valve 23 is switched to the third working state, the second liquid inlet 231 and the first working port 233 are cut off, the second liquid inlet 231 and the second liquid outlet 232 are cut off, and the second liquid outlet 232 and the first working port 233 are communicated. And since the first working port 233 and the control chamber 22 are connected by a first one-way valve 8, the liquid can only flow unidirectionally from the first working port 233 to the control chamber 22, and will not flow back to the liquid return tank 4 through the control chamber 22 and the first valve chamber 141 via the second liquid outlet 232, so as to ensure that the pressure in the first valve chamber 141 remains stable when the first electromagnet is powered off. Specifically, as Figure 3 and Figure 4 shown, a first one-way valve 8 is provided between the first reversing valve 23 and the overflow valve 1. The second liquid outlet 232 of the first reversing valve 23 is connected to the liquid return tank 4. Specifically, the first one-way valve 8 is arranged in the pilot valve body 21. A third flow channel 29 is provided in the pilot valve body 21. The first one-way valve 8 is communicated with the first working port 233 through the third flow channel 29, and the first one-way valve 8 is communicated with the control chamber 22 through a fourth flow channel 210. Wherein, the first one-way valve 8 includes a first one-way valve seat 81 and a first one-way valve core 82. A fifth valve chamber is provided in the first one-way valve seat 81. The first one-way valve core 82 is slidably arranged in the fifth valve chamber. A first through hole 83 communicated with the third flow channel 29 is provided on the outer periphery of the first one-way valve seat 81. A second through hole 84 communicated with the fourth flow channel 210 is provided at one end of the first one-way valve seat 81. Wherein, one end of the first one-way valve core 82 has a clamping portion for cooperating with the first one-way valve seat 81 to communicate or cut off the first through hole 83 and the second through hole 84. The liquid in the first working port 233 enters the fourth flow channel 210 through the third flow channel 29, the first through hole 83 and the second through hole 84, and then enters the control chamber 22. Wherein, the liquid can only flow from the first through hole 83 to the second through hole 84, and will not flow from the second through hole 84 to the first through hole 83, which can ensure that the pressure at the first liquid inlet 11 of the electro-hydraulic overflow valve group remains unchanged when the first electromagnet is powered off.

[0055] It should be noted that for the first reversing valve 23 having a second liquid outlet 232, optionally, similar functions to the scheme of setting the first one-way valve 8 can be achieved by blocking the second liquid outlet 232. The pressure locking function is realized, and the pressure remains stable and unchanged when powered off, ensuring the accuracy of pressure regulation.

[0056] Furthermore, in some embodiments, as Figure 1 and Figure 3As shown, the second reversing valve 24 includes a third liquid inlet 241 and a second working port 243. The third liquid inlet 241 is in communication with the control chamber 22, and the second working port 243 is in communication with the liquid return tank 4. For example, it is a two-position two-way valve. Among them, the second reversing valve 24 has a second working state and a fourth working state. The electromagnetic pilot valve 2 includes a second electromagnet. By controlling the second reversing valve 24 to switch to the second working state, the pressure of the first liquid inlet 11 can be reduced, that is: when controlling the second electromagnet to be energized to switch the second reversing valve 24 to the second working state, the third liquid inlet 241 and the second working port 243 are in communication. Furthermore, the high-pressure liquid in the first valve chamber 141 passes through the control chamber 22 and then enters the liquid return tank 4 through the second working port 243, thereby reducing the pressure in the first valve chamber 141. The pressure above the valve core 15 decreases, causing the valve core 15 to move downward, the opening between the first liquid inlet 11 and the first liquid outlet 12 becomes larger, and the pressure of the first liquid inlet 11 decreases accordingly. By controlling the second electromagnet to be de-energized, the second reversing valve 24 can be switched to the fourth working state. At this time, the third liquid inlet 241 and the third working port are cut off.

[0057] In another embodiment, such as Figure 1 and Figure 3As shown, the second reversing valve 24 includes a third liquid inlet 241, a third liquid outlet 242, and a second working port 243. The third liquid inlet 241 is in communication with the control chamber 22, the third liquid outlet 242 is in communication with the liquid return tank 4, and the second working port 243 is in communication with the liquid return tank 4. For example, a two-way three-way valve. A second check valve 9 is provided between the second working port 243 and the liquid return tank 4. Among them, the second reversing valve 24 has a second working state and a fourth working state. The electromagnetic pilot valve 2 includes a second electromagnet. By controlling the second reversing valve 24 to switch to the second working state, the pressure at the first liquid inlet 11 can be reduced, that is: when the second electromagnet is controlled to be energized to switch the second reversing valve 24 to the second working state, the third liquid inlet 241 and the third liquid outlet 242 are cut off, the third liquid outlet 242 and the second working port 243 are cut off, and the third liquid inlet 241 is in communication with the second working port 243. Furthermore, the high-pressure liquid in the first valve chamber 141 enters the liquid return tank 4 through the control chamber 22 and then through the second working port 243, thereby reducing the pressure in the first valve chamber 141. The pressure above the valve core 15 decreases, causing the valve core 15 to move downward, and the opening degree between the first liquid inlet 11 and the first liquid outlet 12 becomes larger, and the pressure at the first liquid inlet 11 decreases accordingly. By controlling the second electromagnet to be de-energized, the second reversing valve 24 can be switched to the fourth working state. When the second reversing valve 24 is switched to the fourth working state, the third liquid inlet 241 and the third liquid outlet 242 are cut off, the third liquid inlet 241 and the third working port are cut off, and the third liquid outlet 242 is in communication with the second working port 243. Since the second check valve 9 is provided between the second working port 243 and the liquid return tank 4, the liquid can only flow along the second working port 243 to the liquid return tank 4 and will not flow back from the liquid return tank 4 to the second working port 243 (control chamber 22), ensuring the safe operation of the electro-hydraulic control overflow valve group 1.

[0058] Furthermore, the electro-hydraulic control overflow valve group is connected to the controller, and the controller is configured to switch the first reversing valve 23 to the first working state when the pressure at the first liquid inlet 11 is lower than the first preset value, and switch the second reversing valve 24 to the second working state when the pressure at the first liquid inlet 11 is higher than the second preset value. Here, the first preset value and the second preset value refer to the pressure values of the first liquid inlet 11 required by the system set in advance. Between the first preset value and the second preset value, the system can ensure safe and stable operation. Among them, the first preset value is the lower limit value of the pressure at the first liquid inlet 11, and the second preset value is the upper limit value of the pressure at the first liquid inlet 11. By remotely controlling the first reversing valve 23 and the second reversing valve 24, the pressure regulation of the overflow valve 1 can be realized, and precise adjustment can be carried out, thereby realizing the intelligent control of the electro-hydraulic control overflow valve group.

[0059] Furthermore, asFigure 3 As shown, a third valve cavity and a fourth valve cavity are further provided in the pilot valve body 21. A first pressure regulating part 25 is slidably arranged in the third valve cavity, and a second pressure regulating part 26 is slidably arranged in the fourth valve cavity. A first chamber 27 is formed between the first pressure regulating part 25 and the pilot valve body 21, and a second chamber 28 is formed between the second pressure regulating part 26 and the pilot valve body 21. The control chamber 22 is communicated with the first chamber 27 and the second chamber 28 respectively. The first chamber 27 is communicated with the first liquid inlet 11, and the second chamber 28 is communicated with the first liquid outlet 12. Here, the first pressure regulating part 25 and the second pressure regulating part 26 are respectively an adjusting plug or a stop valve, which play the role of manual pressure regulation. When the pressure is regulated by the first reversing valve 23 and the second reversing valve 24, the first pressure regulating part 25 and the second pressure regulating part 26 are respectively adjusted to block the third valve cavity and the fourth valve cavity. This electronically controlled overflow valve group retains the function of manual adjustment, can select two ways of electronic control adjustment and manual adjustment according to user needs, and has a wider application range.

[0060] Specifically, when the pressure of the overflow valve 1 is regulated by the first pressure regulating part 25 and the second pressure regulating part 26, if it is necessary to increase the pressure of the first liquid inlet 11 of the overflow valve 1, adjust the position of the first pressure regulating part 25 in the third valve cavity to increase the space of the first chamber 27. The liquid entering the overflow valve body 13 through the first liquid inlet 11 enters the first valve cavity 141 through the first chamber 27 along the first flow channel 18, thereby increasing the pressure of the first valve cavity 141. The pressure above the valve core 15 increases, causing the valve core 15 to move downward, the opening between the first liquid inlet 11 and the first liquid outlet 12 decreases, and the pressure of the first liquid inlet 11 increases accordingly. If it is necessary to decrease the pressure of the first liquid inlet 11 of the overflow valve 1, adjust the position of the second pressure regulating part 26 in the fourth valve cavity to increase the space of the second chamber 28. The high-pressure liquid in the first valve cavity 141 enters the first liquid outlet 12 along the second chamber 28 and the second flow channel 19, and then flows into the liquid return tank 4, thereby decreasing the pressure of the first valve cavity 141. The pressure above the valve core 15 decreases, causing the valve core 15 to move upward, the opening between the first liquid inlet 11 and the first liquid outlet 12 increases, and the pressure of the first liquid inlet 11 decreases accordingly.

[0061] In some other embodiments, when the first reversing valve and the second reversing valve fail electronically or cannot be used for other reasons, manual control can be adopted to keep the system working normally.

[0062] A second filter is arranged between the first liquid inlet 11 and the first pressure regulating part 25. The second filter filters the liquid entering the first valve cavity 141 from the first liquid inlet 11 to avoid impurities from entering, thereby prolonging the service life of the electronically controlled overflow valve group.

[0063] The second embodiment of the present invention provides a pressure regulating method, as Figure 5 and Figure 6As shown below, specifically including:

[0064] S100: Determine the set value and the allowable deviation range of pressure regulation based on the first preset value and the second preset value of the system pressure. The first preset value is less than the second preset value. The set value and the allowable deviation range are respectively between the first preset value and the second preset value, and the set value is within the allowable deviation range.

[0065] Among them, the first preset value and the second preset value are pressure values preset by the operator according to system requirements, and the first preset value is less than the second preset value. Here, the first preset value is the lower limit value of the system pressure, and the second preset value is the upper limit value of the system pressure. The set value here refers to the expected pressure value adjusted by the operator through the electronic control overflow valve group. The size of the set value is between the first preset value and the second preset value. If the set value is set to the first preset value (lower limit value), then after the system pressure is adjusted to the first preset value, the system pressure value will fluctuate around the first preset value, resulting in the system pressure value may not be sufficient to reach the pressure value required by the system, affecting the normal operation of the system; similarly, if the set value is set to the second preset value (upper limit value), then after the system pressure is adjusted to the second preset value, the system pressure value will fluctuate around the second preset value, resulting in the system pressure value may be higher than the pressure value required by the system, which will also affect the normal operation of the system. Therefore, in this solution, the set value is set to a value between the first preset value and the second preset value, making the set value more specific and more targeted when adjusting the system pressure, and can ensure the safe operation of the system. Exemplarily, the set value is set to the intermediate value of the first preset value and the second preset value. For example, the first preset value is 4 MPa and the second preset value is 6 MPa, then the set value is 5 MPa. Further, when adjusting the system pressure, if the pressure is adjusted to this determined set value, it may be difficult to adjust the system pressure to the set value even after multiple pressure adjustments, and it is difficult to achieve in actual operation. Therefore, an allowable deviation range is set. During adjustment, as long as the system pressure is adjusted within the allowable deviation range of the set value. Here, the allowable deviation range is limited by the set upper limit value and the set lower limit value. The allowable deviation range is the range value between the set upper limit value and the set lower limit value. The set lower limit value is between the set value and the first preset value, and the set upper limit value is between the set value and the second preset value. For example, the set value is 5 MPa and the allowable deviation range is 0.5 MPa, that is, adjusting the system pressure to 4.75 - 5.25 MPa is regarded as achieving the pressure adjustment of the system.

[0066] S200: Obtain the system pressure value, and the system pressure value is the pressure at the first liquid inlet 11.

[0067] Specifically, a pressure detection device 6 is installed on the pilot valve body 21 to detect the pressure at the first liquid inlet 11.

[0068] S300: Determine an adjustment strategy based on the system pressure value.

[0069] After completing the above step S100, in this step, an adjustment strategy is determined based on the size of the system pressure value.

[0070] Specifically, it includes: when the system pressure value is greater than the second preset value, determining that the adjustment strategy is to lower the pressure of the first valve chamber 141; when the system pressure value is less than the first preset value, determining that the adjustment strategy is to increase the pressure of the first valve chamber 141; when the system pressure value is equal to the first preset value (or the second preset value), no adjustment is required.

[0071] S400: Based on the adjustment strategy, the electromagnetic pilot valve 2 is controlled to adjust the pressure of the first valve chamber 141 of the relief valve 1 to adjust the system pressure value to within the allowable deviation range.

[0072] After completing the above step S200, in this step, the electromagnetic pilot valve 2 is controlled based on the adjustment strategy to adjust the pressure of the first valve chamber 141 of the relief valve 1 to adjust the system pressure value to within the allowable deviation range.

[0073] Specifically, when it is determined that the adjustment strategy is to increase the pressure of the first valve chamber 141, the controller sends a pressure increase signal to the solenoid pilot valve 2, and the first reversing valve 23 of the solenoid pilot valve 2 switches to the first working state to connect the first working port 233 and the second liquid inlet 231, and adjusts the system pressure value to within the allowable deviation range; when it is determined that the adjustment strategy is to lower the pressure of the first valve chamber 141, the controller sends a pressure reduction signal to the solenoid pilot valve 2, and the second reversing valve 24 of the solenoid pilot valve 2 switches to the second working state to connect the third liquid inlet 241 and the second working port 243 of the second reversing valve, and adjusts the system pressure value to within the allowable deviation range.

[0074] In another embodiment, after completing the above step S200, in this step, the electromagnetic pilot valve 2 is controlled based on the adjustment strategy, the pressure of the first valve chamber 141 of the relief valve 1 is adjusted, and the system pressure value is adjusted to within the allowable deviation range.

[0075] Specifically, when it is determined that the adjustment strategy is to increase the pressure of the first valve chamber 141 , the first pressure regulating unit 25 is adjusted to connect the first chamber 27 with the control chamber 22 , and to connect the first chamber 27 with the first liquid inlet 11 ;

[0076] When it is determined that the adjustment strategy is to lower the pressure in the first valve chamber 141, adjust the second pressure regulating part 26 to communicate the second chamber 28 with the control chamber 22, and communicate the second chamber 28 with the first liquid outlet 12.

[0077] Applying the pressure regulation method of the electronically controlled overflow valve group provided by the present invention, the user only needs to set the first preset value (pressure upper limit value), the second preset value (pressure lower limit value), the set value and the allowable deviation range value to achieve pressure regulation, and can set parameters according to different working conditions, with strong executability; when adjusting the pressure during operation, when the pressure is adjusted within the allowable deviation range, it is regarded as the end of pressure regulation, which can reduce the number of pressure regulation times.

[0078] Based on the same inventive concept, the third embodiment of the present disclosure provides a pressure regulation device for an electric overflow valve, and the device can be integrated on an electronic device. The device includes: an acquisition module, a strategy generation module and a pressure regulation module, specifically including:

[0079] A determination module, configured to determine a set value and an allowable deviation range for pressure regulation based on a first preset value and a second preset value of the system pressure, the first preset value being less than the second preset value, the set value and the allowable deviation range being respectively between the first preset value and the second preset value, and the set value being within the allowable deviation range;

[0080] An acquisition module, configured to acquire a system pressure value, and the system pressure value is the pressure of the first liquid inlet 11;

[0081] A strategy generation module, configured to determine an adjustment strategy based on the magnitude of the system pressure value;

[0082] A pressure regulation module, configured to control the electromagnetic pilot valve 2 based on the adjustment strategy, adjust the pressure in the first valve chamber 141 of the overflow valve 1, and adjust the system pressure value within the allowable deviation range.

[0083] Applying a pressure regulation device for an electric overflow valve provided by the present invention, the user only needs to set the first preset value (pressure lower limit value), the second preset value (pressure upper limit value), the set value and the allowable deviation range value to achieve pressure regulation, and can set parameters according to different working conditions, with strong executability; when adjusting the pressure during operation, when the pressure is adjusted within the allowable deviation range, it is regarded as the end of pressure regulation, which can reduce the number of pressure regulation times.

[0084] Correspondingly, the fourth embodiment of the present disclosure provides a storage medium, which is a computer-readable medium and stores a computer program. When the computer program is executed by a processor, it implements the method provided by the second embodiment of the present disclosure, including the following steps S11 to S13:

[0085] S11: Based on a first preset value and a second preset value of the system pressure, determine a set value for pressure regulation and an allowable deviation range. The first preset value is less than the second preset value. The set value and the allowable deviation range are respectively between the first preset value and the second preset value, and the set value is within the allowable deviation range.

[0086] S12: Obtain the system pressure value, where the system pressure value is the pressure at the first liquid inlet 11.

[0087] S13: Determine an adjustment strategy based on the magnitude of the system pressure value.

[0088] S14: Based on the adjustment strategy, control the electromagnetic pilot valve 2 to adjust the pressure in the first valve chamber 141 of the overflow valve 1, and adjust the system pressure value within the allowable deviation range.

[0089] When applying the storage medium provided by the present invention, the user only needs to set the first preset value (pressure lower limit value), the second preset value (pressure upper limit value), the set value, and the allowable deviation range value to achieve pressure regulation, and can set parameters according to different working conditions, with strong executability; when adjusting the pressure during operation due to a change in pressure, adjusting the pressure within the allowable deviation range is regarded as the end of pressure regulation, which can reduce the number of pressure regulation times.

[0090] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0091] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0092] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above drawings are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order different from those illustrated or described herein.

[0093] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0094] The above storage medium may be included in the above electronic device; or it may exist independently and not be assembled into the electronic device.

[0095] The above storage medium carries one or more programs. When the above one or more programs are executed by the electronic device, the electronic device is caused to: obtain at least two Internet protocol addresses; send a node evaluation request including at least two Internet protocol addresses to a node evaluation device, wherein the node evaluation device selects an Internet protocol address from the at least two Internet protocol addresses and returns it; receive the Internet protocol address returned by the node evaluation device; wherein the obtained Internet protocol addresses indicate edge nodes in a content distribution network.

[0096] Alternatively, the above storage medium carries one or more programs. When the above one or more programs are executed by the electronic device, the electronic device is caused to: receive a node evaluation request including at least two Internet protocol addresses; select an Internet protocol address from the at least two Internet protocol addresses; return the selected Internet protocol address; wherein the received Internet protocol addresses indicate edge nodes in a content distribution network.

[0097] Computer program code for performing the operations of the present disclosure may be written in one or more programming languages or combinations thereof. The above programming languages include, but are not limited to, object-oriented programming languages such as Java, Smalltalk, C++, and also include conventional procedural programming languages such as the "C" language or similar programming languages. The program code may be executed entirely on the passenger computer, partially on the passenger computer, executed as a stand-alone software package, partially on the passenger computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the passenger computer through any type of network, such as including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (for example, by using an Internet service provider to connect through the Internet).

[0098] It should be noted that the above-mentioned storage medium in this disclosure can be a computer-readable signal medium, a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples of a computer-readable storage medium can include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this disclosure, a computer-readable storage medium can be any tangible medium that contains or stores a program, which can be used by or in conjunction with an instruction execution system, apparatus, or device. And in this disclosure, a computer-readable signal medium can include a data signal propagated in a baseband or as part of a carrier wave, which carries computer-readable program code. Such a propagated data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. A computer-readable signal medium can also be any storage medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the storage medium can be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (radio frequency), etc., or any suitable combination of the above.

[0099] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in the flowchart or block diagram can represent a module, a program segment, or a part of code that contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks can occur in a different order than that marked in the accompanying drawings. For example, two consecutive blocks shown can actually be executed substantially in parallel, and they can sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0100] The units involved in the embodiments of the present disclosure can be implemented in software or in hardware. In some cases, the name of a unit does not constitute a limitation on the unit itself.

[0101] The functions described above herein can be performed, at least in part, by one or more hardware logic components. By way of example, and without limitation, the types of hardware logic components that may be used include: Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), Application Specific Standard Products (ASSPs), Systems on Chip (SOCs), Complex Programmable Logic Devices (CPLDs), and the like.

[0102] In the context of the present disclosure, a machine-readable medium may be a tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of a machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a Read-Only Memory (ROM), an Erasable Programmable Read-Only Memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0103] The above description is only of the preferred embodiments of the present disclosure and an illustration of the technical principles applied. Those skilled in the art should understand that the scope of the disclosure involved in the present disclosure is not limited to the technical solutions formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above disclosure concept. For example, a technical solution formed by mutually replacing the above features with (but not limited to) technical features having similar functions disclosed in the present disclosure.

[0104] In addition, although the operations are depicted in a particular order, this should not be construed as requiring that the operations be performed in the particular order shown or in sequential order. In certain environments, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of the present disclosure. Certain features described in the context of separate embodiments may also be implemented combinatorially in a single embodiment. Conversely, the various features described in the context of a single embodiment may also be implemented separately or in any suitable sub-combination in multiple embodiments.

[0105] Although the subject matter has been described in language specific to structural features and / or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. On the contrary, the specific features and acts described above are merely example forms for implementing the claims.

[0106] The above has described in detail multiple embodiments of the present disclosure, but the present disclosure is not limited to these specific embodiments. Based on the concept of the present disclosure, those skilled in the art can make various variations and modifications to the embodiments, and these variations and modifications should all fall within the scope protected by the present disclosure.

Claims

1. An electronically controlled overflow valve group, characterized in that, It includes an overflow valve and an electromagnetic pilot valve. The overflow valve has a first liquid inlet and a first liquid outlet. The first liquid inlet is connected to a liquid source, and the first liquid outlet is connected to a liquid return tank. The electromagnetic pilot valve includes a first reversing valve and a second reversing valve. The first reversing valve has at least a first working state, and the second reversing valve has at least a second working state. By controlling the first reversing valve to switch to the first working state, the pressure of the first liquid inlet is increased, and by controlling the second reversing valve to switch to the second working state, the pressure of the first liquid inlet is decreased.

2. The electronically controlled overflow valve group according to claim 1, characterized in that The overflow valve includes an overflow valve body. An overflow valve chamber is arranged inside the overflow valve body. The first liquid inlet and the first liquid outlet are respectively communicated with the overflow valve chamber. A movable valve core is arranged inside the overflow valve chamber. The valve core divides the overflow valve chamber into a first valve chamber and a second valve chamber. An elastic member is arranged between the valve core and the overflow valve body.

3. The electronically controlled overflow valve group according to claim 2, characterized in that, The first reversing valve is provided with a second liquid inlet and a first working port. The second liquid inlet is communicated with the first liquid inlet. The first working port is communicated with the first valve chamber. The first reversing valve further includes a third working state. When the first reversing valve switches to the first working state, the first working port is communicated with the second liquid inlet. When the first reversing valve switches to the third working state, the first working port is cut off from the second liquid inlet. The second reversing valve is provided with a third liquid inlet and a second working port. The third liquid inlet is communicated with the first valve chamber. The second working port is communicated with the liquid return tank. The second reversing valve further includes a fourth working state. When the second reversing valve switches to the second working state, the third liquid inlet is communicated with the second working port. When the second reversing valve switches to the fourth working state, the third liquid inlet is cut off from the second working port.

4. The electronically controlled overflow valve group according to claim 3, characterized in that, The first reversing valve is provided with a second liquid outlet. The second liquid outlet is communicated with the liquid return tank. A first one-way valve is arranged between the first working port and the first valve chamber to enable the liquid to flow unidirectionally from the first reversing valve to the overflow valve.

5. The electronically controlled overflow valve group according to claim 3, characterized in that, The second reversing valve is provided with a third liquid outlet. The third liquid outlet is communicated with the liquid return tank. A second one-way valve is arranged between the second working port and the liquid return tank to enable the liquid to flow unidirectionally from the second working port to the liquid return tank.

6. The electronically controlled overflow valve group according to claim 2, wherein The electromagnetic pilot valve further includes a pilot valve body. A control chamber is arranged inside the pilot valve body. The control chamber is communicated with the first valve chamber. A first pressure regulating part and a second pressure regulating part are further arranged inside the pilot valve body. The first pressure regulating part and the pilot valve body form a first chamber. The second pressure regulating part and the pilot valve body form a second chamber. The control chamber is respectively communicated with the first chamber and the second chamber. The first chamber is communicated with the first liquid inlet. The second chamber is communicated with the first liquid outlet.

7. A pressure regulation method, characterized in that, Applied to the electronically controlled overflow valve group according to any one of claims 1-6, it includes: Based on a first preset value and a second preset value of the system pressure, determine a set value for pressure adjustment and an allowable deviation range. The first preset value is less than the second preset value, and the set value and the allowable deviation range are respectively between the first preset value and the second preset value, and the set value is within the allowable deviation range. Obtain the system pressure value, which is the pressure at the first liquid inlet. Based on the magnitude of the system pressure value, determine an adjustment strategy. Based on the adjustment strategy, control the electromagnetic pilot valve to adjust the pressure in the first valve chamber of the relief valve and adjust the system pressure value within the allowable deviation range.

8. The pressure regulation method according to claim 7, characterized in that The determining an adjustment strategy based on the magnitude of the system pressure value includes: When the system pressure value is less than the first preset value, determine that the adjustment strategy is to increase the pressure in the first valve chamber. When the system pressure value is greater than the second preset value, determine that the adjustment strategy is to decrease the pressure in the first valve chamber.

9. The pressure adjustment method according to claim 8, wherein When it is determined that the adjustment strategy is to increase the pressure in the first valve chamber, the controller sends a pressure increase signal to the electromagnetic pilot valve, and the first reversing valve of the electromagnetic pilot valve switches to the first working state, so that the first working port of the first reversing valve is communicated with the second liquid inlet, and the system pressure value is adjusted within the allowable deviation range. When it is determined that the adjustment strategy is to decrease the pressure in the first valve chamber, the controller sends a pressure decrease signal to the electromagnetic pilot valve, and the second reversing valve of the electromagnetic pilot valve switches to the second working state, so that the third liquid inlet of the second reversing valve is communicated with the second working port, and the system pressure value is adjusted within the allowable deviation range.

10. The pressure regulation method according to claim 8, characterized in that, When it is determined that the adjustment strategy is to increase the pressure in the first valve chamber, adjust the first pressure regulating part to communicate the first chamber with the control chamber, so that the first chamber is communicated with the first liquid inlet. When it is determined that the adjustment strategy is to decrease the pressure in the first valve chamber, adjust the second pressure regulating part to communicate the second chamber with the control chamber, so that the second chamber is communicated with the first liquid outlet.

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