Pressure control valve, oil injection control method and oil pumping method

Abstract

The present invention relates to the technical field of pressure control valves, and particularly to a pressure control valve, an oil injection control method and an oil pumping method, including: a valve body; a valve seat; a spool guide tube; a main spool; a third channel is arranged in the spool guide tube, and the third channel communicates with the first channel and the inner cavity of the main spool; a switch control mechanism, when the acting force of the medium on the first elastic holding assembly is greater than the elastic force of the first elastic holding assembly, the plugging member closes the third channel; a check structure. This solution can also close the third channel and the second channel and cut off the oil supply to protect the fuel tank when the internal medium pressure of the pressure control valve is greater than the elastic force of the first elastic holding assembly. This solution can also pump and unload oil from the fuel tank, with rich functions and can meet the development trend.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure control valves, and particularly to a pressure control valve, an oil injection control method, and an oil pumping method. Background Art

[0002] A pressure control valve refers to a valve used to control and regulate the pressure of the liquid flow in a hydraulic system. Such a valve works based on the principle of the balance between the liquid pressure acting on the valve core and the spring force.

[0003] After the pressure of the pressure control valve exceeds the limit, it reduces pressure and stabilizes pressure by discharging the medium to the outside of the system. On the one hand, external equipment is required to achieve this, increasing costs and also increasing the overall volume of the pipeline during oil transportation. On the other hand, for the soft oil bladder of equipment such as unmanned aerial vehicles, even if the pressure is reduced for oil supply after being filled with oil, it may still cause damage to the soft oil bladder. And the existing pressure control valves can only perform refueling operations, with a single function, which does not conform to the development trend. Summary of the Invention

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a pressure control valve, an oil injection control method, and an oil pumping method, which are used to solve the problem that the soft oil bladder is damaged due to the failure to cut off the oil path in time in the prior art.

[0005] To achieve the above purpose and other related purposes, the present invention provides a pressure control valve, including:

[0006] A valve body, on which an outlet is provided;

[0007] A valve seat, which is connected to the valve body, and an inlet is provided on the valve seat;

[0008] A valve core guide tube, which is arranged in the valve body, and a first channel is formed between the valve core guide tube and the inner wall of the valve body, and the first channel is communicated with the outlet;

[0009] A main valve core, which is movably arranged in the valve core guide tube along the axial direction of the valve core guide tube. An inner cavity and a throttle hole are provided on the main valve core. The inner cavity of the main valve core is communicated with the inlet through the throttle hole. A second channel communicating the inlet and the first channel is formed between the main valve core and the valve seat. A first elastic member is arranged between the main valve core and the valve core guide tube. The elastic force of the first elastic member on the main valve core causes the main valve core to approach the valve seat to close the second channel. When the medium overcomes the elastic force of the first elastic member, the second channel is opened, and the first channel is communicated with the inlet through the second channel;

[0010] A third channel is arranged in the valve core guide tube, and the third channel communicates the first channel and the inner cavity of the main valve core;

[0011] A switch control mechanism is provided on the valve core guide cylinder, including a first elastic holding component and a blocking component for switching the third channel. The first elastic holding component is connected to the blocking component to keep the third channel in an open state. When the acting force of the medium on the first elastic holding component is greater than the elastic force of the first elastic holding component, the blocking component closes the third channel.

[0012] A check structure is used to prevent the medium from flowing from the third channel into the inner cavity of the main valve core.

[0013] Optionally, the check structure is arranged between the third channel and the inner cavity of the main valve core. The check structure includes a check valve seat and a check valve flap. An inner cavity is provided on the check valve seat. The inner cavity of the check valve seat communicates with the third channel and the inner cavity of the main valve core. Both ends of the check valve flap are respectively abutted against the check valve seat and the first elastic member.

[0014] Optionally, the third channel includes a first liquid guide hole, a first cavity, a second liquid guide hole, a second cavity, and a third liquid guide hole that are sequentially communicated from the liquid inlet direction to the liquid outlet direction. The first liquid guide hole is arranged on the check valve seat along the radial direction of the check valve seat and communicates with the inner cavity of the check valve seat. The second liquid guide hole is arranged on the valve core guide cylinder along the axial direction of the valve core guide cylinder. The third liquid guide hole is arranged on the valve core guide cylinder along the radial direction of the valve core guide cylinder. The first cavity is formed by surrounding the inner wall of the valve core guide cylinder and the outer wall of the check valve seat. The second cavity is formed by surrounding the inner wall of the valve core guide cylinder and the first elastic holding component.

[0015] Optionally, the blocking component includes a guide valve core and a guide valve core bolt. Both ends of the guide valve core bolt are respectively connected to the first elastic holding component and the guide valve core. The guide valve core is movably arranged along the axial direction of the check valve seat in the inner cavity of the check valve seat. The diameter of the end of the guide valve core away from the guide valve core bolt is greater than the inner diameter of the check valve seat. When the acting force of the medium on the first elastic holding component is greater than the elastic force of the first elastic holding component, the circumferential side of the end of the guide valve core away from the guide valve core bolt abuts against the inlet of the inner cavity of the check valve seat to close the third channel.

[0016] Optionally, the first elastic holding component includes a second elastic member, a diaphragm pressing plate, a gland, and a diaphragm. The diaphragm is arranged in the diaphragm pressing plate. The first end of the gland presses the end face edge of the diaphragm against the valve core guide cylinder. The diaphragm moves along the axial direction of the valve core guide cylinder under the action of the medium pressure. The second elastic member is arranged between the gland and the diaphragm pressing plate, and the second elastic member is used to prevent the diaphragm pressing plate from moving towards the liquid outlet direction.

[0017] Optionally, the second end of the gland is connected to the inner wall of the valve body.

[0018] Optionally, the second end of the gland is connected to the inner wall of the valve body through a positioning member.

[0019] Optionally, a handle for fixing one end of the liquid outlet and the access pipeline is arranged on the outer wall of the liquid outlet.

[0020] In an embodiment of the present invention, an oil injection control method is further provided. Based on the above pressure control valve, the method includes:

[0021] When a pressure medium is injected into the liquid inlet, a part of the medium enters the inner cavity of the main valve core through the throttle hole, then enters the first channel through the third channel, and flows out from the liquid outlet; and the check structure prevents the medium from flowing back from the third channel to the throttle hole of the main valve core;

[0022] Another part of the medium pushes the main valve core towards the liquid outlet direction, and the second channel is in an open state. This part of the medium sequentially passes through the second channel and the first channel, and flows out from the liquid outlet;

[0023] When the acting force of the pressure medium in the pressure control valve on the first elastic holding assembly is greater than the elastic force of the first elastic holding assembly, the first elastic holding assembly drives the plugging component to close the third channel;

[0024] The medium continues to enter the inner cavity of the main valve core through the throttle hole, and the pressure in the inner cavity of the main valve core gradually increases; the medium in the inner cavity of the main valve core pushes the main valve core towards the liquid inlet direction until the main valve core abuts against the valve seat to close the second channel.

[0025] In an embodiment of the present invention, an oil pumping method is further provided. Based on the above pressure control valve, the method includes:

[0026] Through negative pressure suction from the liquid inlet, due to the action of the check component, it prevents the medium from flowing from the liquid outlet to the liquid inlet through the third channel;

[0027] The medium in the inner cavity of the main valve core is sucked out, resulting in a decrease in the pressure in the inner cavity of the main valve core,

[0028] The medium flows from the first channel to the second channel, and the medium squeezes the main valve core towards the liquid outlet direction, so that the second channel is opened, thereby connecting the liquid outlet and the liquid inlet through the first channel and the second channel.

[0029] As described above, the pressure control valve of the present invention has the following beneficial effects:

[0030] The medium enters the pressure control valve from the liquid inlet, and divides into two paths to pass through inside the pressure control valve. For the first path, the medium enters the inner cavity of the main valve core from the throttle hole, passes through the third channel into the first channel, and finally reaches the liquid outlet. For the second path, the medium pushes the main valve core to move towards the liquid outlet direction, causing the main valve core to overcome the elastic force of the first elastic component, thereby opening the second channel formed between the bottom of the main valve core and the inner cavity bottom wall of the valve seat, making the liquid inlet communicate with the first channel. The medium enters the first channel through the second channel and finally reaches the liquid outlet.

[0031] When the acting force of the medium on the first elastic holding component is greater than the elastic force of the first elastic holding component, the blocking component closes the third channel. The medium cannot enter the first channel through the third channel, so the first oil path is closed. The medium continues to enter the inner cavity of the main valve core from the throttle hole, but cannot enter the first channel through the third channel, making the medium pressure inside the inner cavity of the main valve core increase continuously. The medium inside the inner cavity of the main valve core pushes the inner cavity bottom wall of the main valve core towards the liquid inlet direction, and under the elastic force of the first elastic component, the main valve core moves towards the liquid inlet direction until the bottom of the main valve core abuts against the inner cavity bottom wall of the valve seat. Thus, the second channel is closed and the second oil path is also closed.

[0032] When pumping and discharging oil from the fuel tank, due to the setting of the check structure, the medium cannot flow from the third channel into the inner cavity of the main valve core, so the medium can only flow from the liquid outlet through the first channel to the second channel. Under the action of the pumping negative pressure at the access end of the liquid inlet, the medium inside the inner cavity of the main valve core is pumped out through the throttle hole. The medium pressure inside the inner cavity of the main valve core decreases, and the medium flowing from the liquid outlet through the first channel to the second channel squeezes the main valve core towards the liquid outlet direction at this time, overcoming the elastic force of the first elastic component, thereby opening the second channel and pumping and discharging the medium from the fuel tank.

[0033] This solution can close the third channel and the second channel and cut off the oil supply to protect the fuel tank when the medium pressure inside the pressure control valve is greater than the elastic force of the first elastic holding component. This solution can also pump and discharge oil from the fuel tank, with rich functions and can meet the development trend. Description of the Drawings

[0034] Figure 1 is a schematic structural diagram of an embodiment of the present invention;

[0035] Figure 2 is a partial enlarged view of part A of an embodiment of the present invention.

[0036] Description of Part Numbers

[0037] 1 - Liquid inlet; 2 - Liquid outlet; 3 - Valve seat; 4 - Main spool valve; 41 - Throttle orifice; 42 - First elastic member; 5 - Valve body; 51 - First channel; 52 - Handle; 6 - Spool guide cylinder; 61 - First cavity; 62 - Second liquid guide hole; 63 - Second cavity; 64 - Third liquid guide hole; 71 - Check valve seat; 72 - Check valve flap; 73 - First liquid guide hole; 81 - Pilot spool valve; 82 - Pilot spool valve bolt; 91 - Diaphragm; 92 - Diaphragm pressing plate; 93 - Gland; 94 - Second elastic member. Detailed implementation mode

[0038] The following uses specific specific examples to illustrate the implementation mode of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0039] It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the drawings, rather than being drawn according to the number, shape, and size of the components during actual implementation. The type, quantity, and proportion of each component during actual implementation can be arbitrarily changed, and the component layout type may also be more complex. The structures, proportions, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have technical essence. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear description and are not used to limit the scope for the implementation of the present invention. The change or adjustment of their relative relationship, without substantial change in the technical content, should also be regarded as the scope for the implementation of the present invention.

[0040] Please refer to Figure 1, this embodiment provides a pressure control valve, which includes a valve body 5, a valve seat 3, a spool guide cylinder 6, a main spool 4, a switch control mechanism, and a check mechanism. An outlet 2 is provided at the top of the valve body 5. The outer wall at the top of the valve seat 3 is connected to the inner wall at the bottom of the valve body 5. An inlet 1 is provided inside the bottom of the valve seat 3, and the inlet 1 is communicated with the outlet 2. The spool guide cylinder 6 is fixedly arranged inside the valve body 5, and the bottom end surface of the spool guide cylinder 6 is arranged on the inner cavity bottom wall of the valve seat 3. A first channel 51 is formed between the outer wall of the spool guide cylinder 6 and the inner wall of the valve body 5, and the top of the first channel 51 is communicated with the outlet 2. The main spool 4 is movably arranged inside the spool guide cylinder 6 along the axial direction of the spool guide cylinder 6. The main spool 4 is U-shaped, and an inner cavity is provided inside the main spool 4. A throttle hole 41 is provided at the bottom, and the throttle hole 41 communicates the inlet 1 with the inner cavity of the main spool 4. A groove is arranged along the axial direction on the inner wall of the spool guide cylinder 6, and the top of the main spool 4 can slide along the axial direction of the spool guide cylinder 6 inside the groove. A second channel is formed between the bottom of the main spool 4 and the inner cavity bottom wall of the valve seat 3. The lower end of the second channel is communicated with the inlet 1, and the upper end of the second channel is communicated with the first channel 51. A first elastic member 42 is arranged between the inner cavity bottom wall of the main spool 4 and the inner wall of the spool guide cylinder 6. In one embodiment, the first elastic member 42 includes a spring, and the two ends of the spring respectively abut against the inner cavity bottom wall of the main spool 4 and the inner wall of the spool guide cylinder 6. The elastic force of the first elastic member 42 acts on the main spool 4, so that the bottom of the main spool 4 abuts against the inner cavity bottom wall of the valve seat 3. The medium entering from the inlet 1 overcomes the elastic force of the first elastic member 42 and pushes the main spool 4 towards the outlet 2, so that the bottom of the main spool 4 is separated from the inner cavity bottom wall of the valve seat 3, thereby opening the second channel. A third channel is arranged inside the spool guide cylinder 6, and the third channel communicates the first channel 51 and the inner cavity of the main spool 4. The switch control mechanism is arranged on the spool guide cylinder 6 and includes a first elastic holding assembly and a blocking component. The blocking component is used to switch the third channel. The first elastic holding assembly is connected to the blocking component to keep the blocking component in the open state of the third channel. When the acting force of the medium on the first elastic holding assembly is greater than the elastic force of the first elastic holding assembly, the blocking component closes the third channel. A check structure is arranged inside the spool guide cylinder 6 to prevent the medium from flowing from the third channel to the inner cavity of the main spool.

[0041] The medium enters the pressure control valve from the inlet 1 and is divided into two paths to pass through inside the pressure control valve. For the first path, the medium enters the inner cavity of the main spool 4 from the throttle hole 41, enters the first channel 51 through the third channel, and finally reaches the outlet 2. For the second path, the medium pushes the main spool 4 towards the outlet 2, so that the main spool 4 overcomes the elastic force of the first elastic member 42, thereby opening the second channel formed between the bottom of the main spool 4 and the inner cavity bottom wall of the valve seat 3, so that the inlet 1 is communicated with the first channel. The medium enters the first channel 51 through the second channel and finally reaches the outlet 2.

[0042] When the force exerted by the medium on the first elastic retaining component is greater than the elastic force of the first elastic retaining component, the plugging component closes the third channel. The medium cannot enter the first channel through the third channel, and the first oil circuit is closed. The medium continues to enter the inner cavity of the main spool 4 through the throttle hole 41, but cannot enter the first channel through the third channel, causing the medium pressure in the inner cavity of the main spool 4 to increase. The medium in the inner cavity of the main spool 4 pushes the bottom wall of the inner cavity of the main spool 4 towards the liquid inlet 1, and under the elastic force of the first elastic member 42, the main spool 4 moves towards the liquid inlet 1 until the bottom of the main spool 4 abuts against the bottom wall of the inner cavity of the valve seat 3. Thus, the second channel is closed, and the second oil circuit is also closed.

[0043] In this embodiment, oil can also be pumped out of the fuel tank. Due to the setting of the check structure, the medium cannot flow from the third channel into the inner cavity of the main spool 4. Therefore, the medium can only flow from the liquid outlet 2 through the first channel 51 to the second channel. Under the action of the pumping negative pressure at the access end of the liquid inlet 1, the medium in the inner cavity of the main spool 4 is pumped out through the throttle hole 41. The medium pressure in the inner cavity of the main spool 4 decreases, and the medium flowing from the liquid outlet 2 through the first channel 51 to the second channel squeezes the main spool 4 towards the liquid outlet 2 at this time, overcoming the elastic force of the first elastic member 42, thereby opening the second channel and pumping the medium out of the fuel tank.

[0044] In this embodiment, the setting of the two oil circuits enables one of them to perform the refueling work when the other is damaged, avoiding frequent replacement of the pressure control valve, reducing costs, and improving operation efficiency. This solution can also close the third channel and the second channel when the medium pressure inside the pressure control valve is greater than the elastic force of the first elastic retaining component, cutting off the oil supply to protect the fuel tank. This solution can also pump oil out of the fuel tank, with rich functions and can meet the development trend.

[0045] In one embodiment, as Figure 1 and Figure 2 shown, the check structure is arranged between the third channel and the inner cavity of the main spool 4. The check structure includes a check valve seat 71 and a check valve flap 72. An inner cavity is provided on the spool guide cylinder 6, and the inner diameter of the spool guide cylinder 6 is in a stepped shape that gradually decreases from the liquid inlet 1 to the liquid outlet 2. An inner cavity is provided on the check valve seat 71, and the inner cavity of the check valve seat 71 communicates with the third channel and the inner cavity of the main spool 4. The outer diameter of the check valve seat 71 is in a stepped shape that gradually decreases from the liquid inlet 1 to the liquid outlet 2 and is in mutual cooperation with the inner diameter of the spool guide cylinder 6. A sealing ring is provided between the outer wall of the check valve seat 71 and the inner wall of the spool guide cylinder 6 for sealing. The two ends of the first elastic member 42 respectively abut against the bottom end of the check valve flap 72 and the bottom wall of the inner cavity of the main spool 4. The top end of the check valve flap 72 abuts against the bottom end of the check valve seat 71 to prevent the medium from flowing from the third channel into the inner cavity of the main spool 4.

[0046] In one embodiment, as Figure 1 andFigure 2 As shown, the third channel includes a first liquid guiding hole 73, a first cavity 61, a second liquid guiding hole 62, a second cavity 63, and a third liquid guiding hole 64 that are sequentially connected from the liquid inlet 1 direction to the liquid outlet 2 direction. The first liquid guiding hole 73 is arranged radially along the check valve seat 71 and communicates with the inner cavity of the check valve seat 71, thereby communicating with the inner cavity of the main valve core 4. The first cavity 61 is formed by enclosing the outer wall of the check valve seat 71 and the inner wall of the valve core guide cylinder 6. The second liquid guiding hole 62 is arranged on the valve core guide cylinder 6 along the axial direction of the valve core guide cylinder 6. The second cavity 63 is formed by enclosing the inner wall of the valve core guide cylinder 6 and the inner wall of the first elastic holding assembly. The third liquid guiding hole 64 is arranged on the valve core guide cylinder 6 near one end of the liquid outlet 2 along the radial direction of the valve core guide cylinder 6.

[0047] In one embodiment, as Figure 1 and Figure 2 shown, the blocking component includes a guide valve core 81 and a guide valve core bolt 82. The guide valve core 81 is movably arranged in the inner cavity of the check valve seat 71 along the axial direction of the check valve seat 71. The top end of the guide valve core bolt 82 is arranged on the first elastic holding assembly, and the bottom end is connected to the guide valve core 81. The bottom end diameter of the guide valve core 81 is larger than the inner cavity diameter of the check valve seat 71. The bottom end of the guide valve core 81 is arranged outside the inner cavity of the check valve seat 71. When the acting force of the medium on the first elastic holding assembly is greater than the elastic force of the first elastic holding assembly, the circumferential side of the bottom end of the guide valve core 81 abuts against the bottom inner cavity opening of the check valve seat 71 to close the third channel.

[0048] In one embodiment, as Figure 1 and Figure 2 shown, the bottom end of the guide valve core 81 is a conical surface with a gradually decreasing diameter from the liquid inlet 1 to the liquid outlet 2 direction. When the acting force of the medium on the first elastic holding assembly is greater than the elastic force of the first elastic holding assembly, the function of the conical surface is to gradually reduce the flow rate until it is closed, which can better protect the fuel tank and the oil circuit.

[0049] In one embodiment, as Figure 1 and Figure 2As shown, the first elastic holding component includes a second elastic member 94, a diaphragm pressing plate 92, a gland 93, and a diaphragm 91. The diaphragm 91 is elastic and can deform axially along the valve body 1 under a certain medium pressure. The diaphragm 91 is inserted radially into the diaphragm pressing plate 92 along the radial direction of the diaphragm pressing plate 92, so that the middle part of the diaphragm 91 is arranged inside the diaphragm pressing plate 92. The bottom of the gland 93 is connected to the top end of the valve core guide cylinder 6, and the gland 93 presses the end face edge of the diaphragm 91 against the top end of the valve core guide cylinder 6. An inner cavity is provided on the gland 93, and the second elastic member 94 is arranged between the top wall of the inner cavity of the gland 93 and the top of the diaphragm pressing plate 92. The second elastic member 94 includes a spring and is used to prevent the diaphragm pressing plate 92 from moving towards the liquid outlet 2. When the medium pressure in the pressure control valve is greater than the elastic force of the diaphragm 91, the diaphragm 91 deforms axially along the valve body 5 towards the liquid outlet 2, driving the blocking component to close the third channel.

[0050] In one embodiment, as Figure 1 shown, the top end of the gland 93 is connected to the inner wall of the valve core guide cylinder 6.

[0051] In one embodiment, as Figure 1 shown, the top end of the gland 93 is connected to the inner wall of the valve core guide cylinder 6 through a positioning member, and the positioning member includes a positioning pin tube.

[0052] In one embodiment, as Figure 1 shown, a handle 52 is hingedly arranged on the outer wall of the liquid outlet 2 of the valve body 5. The handle 52 is used to fix the connection between the liquid outlet 2 and the external access pipeline, making the connection between the liquid outlet 2 and the external access pipeline more stable. After the liquid outlet 2 is connected to the external access pipeline, the handle 52 is fastened.

[0053] In an embodiment of the present invention, there is also provided an oil injection control method. Based on the above pressure control valve, the method includes:

[0054] When injecting a pressure medium into the liquid inlet 1, a part of the medium enters the inner cavity of the main valve core 4 through the throttle hole 41, then enters the first channel 51 through the third channel, and flows out from the liquid outlet 2; and the check structure prevents the medium from flowing back from the third channel to the throttle hole 41 of the main valve core 4;

[0055] Another part of the medium pushes the main valve core 4 towards the liquid outlet 2, and the second channel is in an open state. This part of the medium sequentially passes through the second channel and the first channel 51 and flows out from the liquid outlet 2;

[0056] When the acting force of the pressure medium in the pressure control valve on the first elastic holding component is greater than the elastic force of the first elastic holding component, the first elastic holding component drives the blocking component to close the third channel;

[0057] The medium continues to enter the inner cavity of the main valve core 4 through the throttle orifice 41, and the pressure in the inner cavity of the main valve core 4 gradually increases; the medium in the inner cavity of the main valve core 4 pushes the main valve core 4 to move towards the liquid inlet 1 until the main valve core 4 abuts against the valve seat 5 to close the second channel.

[0058] In an embodiment of the present invention, there is also provided an oil pumping method based on the above pressure control valve. The method includes:

[0059] Through negative pressure suction from the liquid inlet 1, due to the action of the check component, the medium is prevented from flowing from the liquid outlet 2 to the liquid inlet 1 through the third channel;

[0060] The medium in the inner cavity of the main valve core 4 is sucked out, resulting in a decrease in the pressure in the inner cavity of the main valve core 4.

[0061] The medium flows from the first channel 51 to the second channel, and the medium squeezes the main valve core 4 towards the liquid outlet 2 to open the second channel, thereby connecting the liquid outlet 2 and the liquid inlet 1 through the first channel 51 and the second channel.

[0062] The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A pressure control valve, characterized in that, Comprising: A valve body, on which a liquid outlet is provided; A valve seat, which is connected to the valve body, and an inlet is provided on the valve seat; A spool guide cylinder, which is arranged in the valve body, and a first channel is formed between the spool guide cylinder and the inner wall of the valve body, and the first channel is communicated with the liquid outlet; A main spool, which is movably arranged in the spool guide cylinder along the axial direction of the spool guide cylinder. An inner cavity and a throttle hole are provided on the main spool. The inner cavity of the main spool is communicated with the inlet through the throttle hole. A second channel communicating the inlet and the first channel is formed between the main spool and the valve seat. A first elastic member is arranged between the main spool and the spool guide cylinder. The elastic force of the first elastic member on the main spool causes the main spool to approach the valve seat to close the second channel. When the medium overcomes the elastic force of the first elastic member, the second channel is opened, and the first channel is communicated with the inlet through the second channel; A third channel is arranged in the spool guide cylinder, and the third channel communicates the first channel and the inner cavity of the main spool; A switch control mechanism is arranged on the spool guide cylinder, including a first elastic holding component and a blocking component for switching the third channel. The first elastic holding component is connected to the blocking component to keep the blocking component in an open state of the third channel. When the acting force of the medium on the first elastic holding component is greater than the elastic force of the first elastic holding component, the blocking component closes the third channel; A check structure for preventing the medium from flowing from the third channel to the inner cavity of the main spool.

2. The pressure control valve according to claim 1, wherein: The check structure is arranged between the third channel and the inner cavity of the main spool. The check structure includes a check valve seat and a check valve flap. An inner cavity is provided on the check valve seat. The inner cavity of the check valve seat communicates the third channel and the inner cavity of the main spool. Two ends of the check valve flap are respectively abutted against the check valve seat and the first elastic member.

3. The pressure control valve according to claim 2, wherein: The third channel includes a first liquid guide hole, a first cavity, a second liquid guide hole, a second cavity and a third liquid guide hole which are sequentially communicated from the inlet direction to the outlet direction. The first liquid guide hole is arranged on the check valve seat along the radial direction of the check valve seat, and the first liquid guide hole is communicated with the inner cavity of the check valve seat. The second liquid guide hole is arranged on the spool guide cylinder along the axial direction of the spool guide cylinder. The third liquid guide hole is arranged on the spool guide cylinder along the radial direction of the spool guide cylinder. The first cavity is formed by surrounding the inner wall of the spool guide cylinder and the outer wall of the check valve seat. The second cavity is formed by surrounding the inner wall of the spool guide cylinder and the first elastic holding component.

4. The pressure control valve according to claim 3, wherein: The plugging component includes a pilot valve core and a pilot valve core bolt. Two ends of the pilot valve core bolt are respectively connected to the first elastic holding assembly and the pilot valve core. The pilot valve core is axially movably arranged in the inner cavity of the check valve seat along the axial direction of the check valve seat. The diameter of one end of the pilot valve core away from the pilot valve core bolt is larger than the inner diameter of the check valve seat. When the acting force of the medium on the first elastic holding assembly is greater than the elastic force of the first elastic holding assembly, the circumferential side of the end of the pilot valve core away from the pilot valve core bolt abuts against the inlet of the inner cavity of the check valve seat to close the third channel.

5. The pressure control valve according to claim 1, wherein: The first elastic holding assembly includes a second elastic member, a diaphragm pressing plate, a gland and a diaphragm. The diaphragm is arranged in the diaphragm pressing plate. The first end of the gland presses the end face edge of the diaphragm against the valve core guide cylinder. The diaphragm moves axially along the valve core guide cylinder under the action of the medium pressure. The second elastic member is arranged between the gland and the diaphragm pressing plate, and the second elastic member is used to prevent the diaphragm pressing plate from moving towards the liquid outlet direction.

6. The pressure control valve according to claim 5, characterized in that: The second end of the gland is connected to the inner wall of the valve body.

7. The pressure control valve according to claim 6, characterized in that: The second end of the gland is connected to the inner wall of the valve body through a positioning member.

8. The pressure control valve according to claim 1, wherein: A handle for fixing the liquid outlet and an external access pipeline is arranged on the outer wall of the liquid outlet.

9. An oil injection control method, based on the pressure control valve according to any one of claims 1-8, characterized in that, The method includes: When a pressure medium is injected into the inlet, a part of the medium enters the inner cavity of the main valve core through the throttle hole, then enters the first channel through the third channel and flows out from the liquid outlet; and the check structure prevents the medium from flowing back from the third channel to the throttle hole of the main valve core. Another part of the medium pushes the main valve core towards the liquid outlet direction, and the second channel is in an open state. This part of the medium sequentially passes through the second channel and the first channel and flows out from the liquid outlet. When the acting force of the pressure medium in the pressure control valve on the first elastic holding assembly is greater than the elastic force of the first elastic holding assembly, the first elastic holding assembly drives the plugging component to close the third channel. The medium continues to enter the inner cavity of the main valve core through the throttle hole, and the pressure in the inner cavity of the main valve core gradually increases; the medium in the inner cavity of the main valve core pushes the main valve core towards the inlet direction until the main valve core abuts against the valve seat to close the second channel.

10. A pumping method, based on the pressure control valve according to any one of claims 1-8, characterized in that, The method includes: Through negative pressure suction from the inlet, due to the function of the check component, the medium is prevented from flowing from the liquid outlet to the inlet through the third channel. The medium in the inner cavity of the main valve core is sucked out, resulting in a decrease in the pressure in the inner cavity of the main valve core. The medium flows from the first channel to the second channel, and the medium squeezes the main valve core towards the liquid outlet direction to open the second channel, so as to connect the liquid outlet and the inlet through the first channel and the second channel.

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