Overflow valve for fluid pipeline

Abstract

The invention relates to the technical field of overflow valves, in particular to an overflow valve for a fluid pipeline. Comprising a first valve seat, the first valve seat is provided with a third valve seat through a second valve seat, the first valve seat is provided with a cylindrical cavity and a pressure relief opening which are communicated with each other, a fixing sleeve is arranged in the cylindrical cavity, the fixing sleeve is provided with a round hole, and a first sliding shell is arranged in the fixing sleeve in a sliding mode; a spring is installed between the first sliding shell and the second valve seat, a sealing ring is arranged on the first sliding shell, the first sliding shell is provided with a second sliding shell in a sliding mode, the second sliding shell and the fixing sleeve slide in a sealing mode, and a tension spring is installed between the second sliding shell and the first sliding shell. And a pilot circulation system is arranged on the first valve seat. The second sliding shell shields the sealing ring, the contact time of the sealing ring and a flowing medium in a pipeline is shortened, the service time of the sealing ring is prolonged, and therefore the service life of the device is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of overflow valves, and particularly to an overflow valve for a fluid pipeline. Background Art

[0002] In a hydraulic system formed by a fluid pipeline, an overflow valve is often installed to prevent the system pressure from exceeding the set value and ensure the safe and stable operation of the system. According to different working principles and application scenarios, overflow valves are mainly divided into direct-acting overflow valves, pilot-operated overflow valves, electromagnetic overflow valves and other types. Among them, the electromagnetic overflow valve has been widely used in modern hydraulic systems because it can achieve fast response and precise control through electrical signals. However, in practical applications, the electromagnetic overflow valve also faces some challenges. As the electromagnetic overflow valve opens to relieve pressure, the sealing ring on the plug moves into contact with the flowing medium. Especially during long-term use, the sealing ring on the plug frequently contacts the flowing medium. Affected by the corrosiveness of the medium transported in the pipeline, the long-term contact between the sealing ring and the transported medium will cause a chemical reaction in the sealing ring, gradually lose its elasticity, reduce the sealing performance, and thus affect its service life. Summary of the Invention

[0003] In order to overcome the problems proposed in the above background art, the present invention provides an overflow valve for a fluid pipeline.

[0004] The technical solution is as follows: An overflow valve for a fluid pipeline includes a first valve seat. The first valve seat is installed with a third valve seat through a second valve seat. The first valve seat is provided with a cylindrical cavity and a pressure relief port that communicate with each other. A fixed sleeve is arranged in the cylindrical cavity. The fixed sleeve is provided with a round hole. A first sliding shell is slidably arranged in the fixed sleeve. A spring is installed between the first sliding shell and the second valve seat. A sealing ring is arranged on the first sliding shell. A second sliding shell that seals and slides with the fixed sleeve is slidably arranged on the first sliding shell. A tension spring is installed between the second sliding shell and the first sliding shell. The second sliding shell is used to cover the sealing ring. The first valve seat is provided with a pilot flow-through system for pre-pressure relief. The third valve seat is fixedly connected with an electromagnetic drive member through a fixed seat. The electromagnetic drive member works to control the on-off state of the pilot flow-through system.

[0005] Preferably, the pilot flow system includes a sliding rod slidably disposed on the fixed seat. A spring is installed between the sliding rod and the fixed seat. The third valve seat is provided with a sliding cavity, and the sliding rod is hermetically slidable within the sliding cavity of the third valve seat. The electromagnetic driving member is used to control the movement of the sliding rod. The first valve seat is provided with a damping hole communicating with the cylindrical cavity. The first valve seat and the second valve seat are jointly provided with a first diversion hole and a fifth diversion hole. The first valve seat is provided with a second diversion hole, wherein the first diversion hole communicates with the damping hole, the second diversion hole is used to communicate the first diversion hole and the cylindrical cavity, the fifth diversion hole communicates with the pressure relief port, the second valve seat and the third valve seat are jointly provided with a third diversion hole and a fourth diversion hole, the third diversion hole communicates with the first diversion hole, the fourth diversion hole communicates with the fifth diversion hole, and both the third diversion hole and the fourth diversion hole communicate with the sliding cavity on the third valve seat.

[0006] Preferably, the sliding rod is provided with a reduced-diameter plug. The reduced-diameter plug of the sliding rod is made of metal. A section of the sliding cavity on the third valve seat between the third diversion hole and the fourth diversion hole is a blocking section, and the reduced-diameter plug on the sliding rod is hermetically slidable with the blocking section of the sliding cavity on the third valve seat.

[0007] Preferably, an annular air cavity is provided in the middle of the sealing ring. The fixed sleeve is provided with an annular groove, and the sealing ring contacts the annular groove on the fixed sleeve.

[0008] Preferably, a third sliding shell is hermetically slidably disposed in the second sliding shell. A spring is installed between the third sliding shell and the second sliding shell, and the third sliding shell is hermetically slidable with the fixed sleeve. The third sliding shell, the fixed sleeve and the second sliding shell form an annular chamber one filled with gas, and the second sliding shell and the first sliding shell form an annular chamber two filled with gas. The second sliding shell is provided with a through hole for communicating the annular chamber one and the annular chamber two, and the first sliding shell is provided with a through hole for communicating the annular chamber two and the annular air cavity on the sealing ring.

[0009] Preferably, it further includes:

[0010] A first threaded plug threadedly installed on the second valve seat. The second valve seat is provided with a pilot chamber;

[0011] A cylindrical sleeve fixedly connected to the first threaded plug. A sliding sleeve is slidably disposed in the cylindrical sleeve. A spring is installed between the sliding sleeve and the cylindrical sleeve, and both the sliding sleeve and the cylindrical sleeve are in contact with the second valve seat;

[0012] A second threaded plug is threadedly installed on the second valve seat. The second threaded plug is provided with a threaded rod. A sealing plug is slidably arranged on the threaded rod. A spring is installed between the sealing plug and the threaded rod. The sealing plug is used to seal the sliding sleeve, and the contact position between the sealing plug and the sliding sleeve is located between the first diversion hole and the fifth diversion hole.

[0013] Preferably, both the sealing plug and the sliding sleeve are made of metal. The sealing plug is provided with a round table surface, and the sliding sleeve is provided with a round table surface. The round table surface of the sealing plug contacts the round table surface of the sliding sleeve to improve the sealing performance between the two.

[0014] Preferably, when the threaded rod is rotated, the elastic potential energy of the spring between it and the sealing plug is changed.

[0015] Preferably, a sliding plug is sealingly and slidably arranged on the sealing plug. The sliding plug penetrates through the threaded rod and is slidably connected to it. The cylindrical sleeve is provided with a cylindrical surface, and the sliding plug is sealingly and slidably in contact with the cylindrical surface of the cylindrical sleeve.

[0016] Preferably, the threaded rod is fixedly connected with a fixed shell. The fixed shell is filled with a liquid medium. A sliding plate is sealingly and slidably arranged in the fixed shell. A tension spring is installed between the sliding plate and the fixed shell. The sliding plug penetrates through the fixed shell and is sealingly and slidably connected to it. The sliding plug is fixedly connected with the sliding plate. The sliding plate is provided with a plurality of through holes.

[0017] The beneficial effects are as follows: In the present invention, through the shielding of the second sliding shell on the sealing ring, the contact time between the sealing ring and the flowing medium in the pipeline is reduced, the service life of the sealing ring is prolonged, and thus the service life of the present device is prolonged; by the contact between the sealing plug and the cylindrical sleeve, a mechanical pressure relief part is formed to ensure that when the power is off or the electromagnetic driving part is damaged, the present device can still perform the pressure relief operation to maintain the stability of the pressure in the pipeline; through the relative sliding between the sliding sleeve and the cylindrical sleeve, the pressure fluctuation in the pipeline is buffered to reduce the occurrence of accidental pressure relief operation; through the resistance of the sliding plate moving in the fixed shell, the separation of the sealing plug and the sliding sleeve is prevented, thereby preventing unnecessary pressure relief operation of the present device caused by short-term pressure fluctuation and ensuring the continuity and stability of the liquid medium transportation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a three-dimensional structural schematic diagram of the present invention;

[0019] Figure 2 is a cross-sectional view of the first valve seat and the second valve seat of the present invention;

[0020] Figure 3 is a cross-sectional view of the first valve seat and the fixed sleeve of the present invention;

[0021] Figure 4 This is a cross-sectional view of the fixed sleeve and the first sliding shell of the present invention;

[0022] Figure 5 This is a cross-sectional view of the second sliding shell and the third sliding shell of the present invention;

[0023] Figure 6 This is a cross-sectional view of the cylindrical sleeve and the sliding sleeve of the present invention;

[0024] Figure 7 This is a cross-sectional view of the threaded rod and the fixed shell of the present invention.

[0025] In the reference numerals: 1 - first valve seat, 2 - second valve seat, 3 - third valve seat, 4 - cylindrical cavity, 5 - fixed sleeve, 6 - pressure relief port, 7 - first sliding shell, 701 - sealing ring, 702 - second sliding shell, 8 - damping hole, 9 - first diversion hole, 10 - second diversion hole, 11 - third diversion hole, 12 - fourth diversion hole, 13 - fifth diversion hole, 14 - fixed seat, 15 - electromagnetic drive member, 16 - sliding rod, 18 - third sliding shell, 19 - first threaded plug, 20 - cylindrical sleeve, 201 - sliding sleeve, 21 - second threaded plug, 22 - threaded rod, 23 - sealing plug, 24 - sliding plug, 25 - fixed shell, 26 - sliding plate. Detailed implementation manners

[0026] The present invention will be further described below in conjunction with the embodiments shown in the drawings.

[0027] Embodiment 1: An overflow valve for a fluid pipeline, as Figures 1-4As shown, it includes a first valve seat 1, the first valve seat 1 is bolted with a second valve seat 2, the second valve seat 2 is bolted with a third valve seat 3, the lower part of the first valve seat 1 is provided with a cylindrical cavity 4 and a pressure relief port 6 which are interconnected, the cylindrical cavity 4 is communicated with a fluid pipeline, the pressure relief port 6 is connected with a collecting bucket, and the collecting bucket is used to collect the liquid medium discharged during pressure relief, a fixing sleeve 5 is placed in the cylindrical cavity 4, the fixing sleeve 5 is used to separate the cylindrical cavity 4 and the pressure relief port 6, and three rubber rings are provided on the fixing sleeve 5, two of which are located at the upper part of the fixing sleeve 5, and one rubber ring is located at the lower part of the fixing sleeve 5, which are used to improve the sealing between the fixing sleeve 5 and the first valve seat 1, and the fixing sleeve 5 is fixed. The upper surface of the fixed sleeve 5 is in close contact with the second valve seat 2. The fixed sleeve 5 is provided with six circular holes for connecting the cylindrical cavity 4 and the pressure relief port 6. The six circular holes are equidistantly distributed in the circumferential direction. A first sliding shell 7 is slidably arranged in the fixed sleeve 5. A spring is installed between the first sliding shell 7 and the second valve seat 2. The spring between the first sliding shell 7 and the second valve seat 2 is always in a compressed state. Two sealing rings 701 are arranged at the lower part of the first sliding shell 7. A second sliding shell 702 is slidably arranged at the upper part of the first sliding shell 7. The second sliding shell 702 slides in a sealed manner with the fixed sleeve 5. Two rubber rings are arranged on the second sliding shell 702. The second sliding shell 702 and the first sliding shell 701 are in a compressed state. A tension spring is installed between the second sliding shell 702 and the first sliding shell 7. In the initial state, the tension spring between the second sliding shell 702 and the first sliding shell 7 is in a stretched state, and the elastic potential energy of the spring between the first sliding shell 7 and the second valve seat 2 is greater than the elastic potential energy of the tension spring between the second sliding shell 702 and the first sliding shell 7. In the blocked state of the relief valve, the second sliding shell 702 is used to block the circular hole on the fixed sleeve 5. In the open state of the relief valve, the second sliding shell 702 is used to cover the two sealing rings 701 to prevent the sealing rings 701 from contacting the flowing medium in the pipeline, thereby extending the service life of the sealing rings 701 and thus extending the service life of the device. The first valve seat 1 is provided with There is a pilot circulation system for pre-pressure relief. A fixing seat 14 is fixedly connected to the right side of the third valve seat 3. An electromagnetic driver 15 is bolted to the right side of the fixing seat 14. The electromagnetic driver 15 is used to control the on-off state of the pilot circulation system. An existing pressure sensor is often installed in the fluid pipeline. The pressure sensor is electrically connected to the electromagnetic driver 15 through the Internet of Things system. When the pressure sensor detects that the pressure in the fluid pipeline is too high, the electromagnetic driver 15 is started by controlling the Internet of Things system to release the blocking state of the pilot circulation system. Subsequently, the liquid medium enters the pressure relief port 6 through the pilot circulation system to divert and relieve the pressure of the liquid medium in the fluid pipeline.

[0028] like Figure 2 and Figure 3As shown, the pilot flow system includes a sliding rod 16, which is slidably arranged on a fixed seat 14. A spring is installed between the sliding rod 16 and the fixed seat 14, and the spring between the sliding rod 16 and the fixed seat 14 is always in a compressed state. The third valve seat 3 is provided with a sliding cavity, and the sliding rod 16 is hermetically slidable in the sliding cavity of the third valve seat 3. An electromagnetic driving member 15 is used to control the movement of the sliding rod 16, and the spring between the sliding rod 16 and the fixed seat 14 is used to block the pilot flow system by the sliding rod 16 initially. The diameter of the damping hole 8 is smaller than that of other flow channels. The first valve seat 1 is provided with a damping hole 8, and the damping hole 8 communicates with the cylindrical cavity 4. The first valve seat 1 and the second valve seat 2 are jointly provided with a first diversion hole 9 and a fifth diversion hole 13, that is, both the first diversion hole 9 and the fifth diversion hole 13 are composed of two sections of channels. The first valve seat 1 is provided with a second diversion hole 10, wherein the first diversion hole 9 communicates with the damping hole 8, and the second diversion hole 10 is used to connect the first diversion hole 9 and the cylindrical cavity 4, and the second diversion hole 10 is located above the cylindrical cavity 4. The fifth diversion hole 13 communicates with the pressure relief port 6. The second valve seat 2 and the third valve seat 3 are jointly provided with a third diversion hole 11 and a fourth diversion hole 12. The third diversion hole 11 communicates with the first diversion hole 9, and the fourth diversion hole 12 communicates with the fifth diversion hole 13. Both the third diversion hole 11 and the fourth diversion hole 12 communicate with the sliding cavity on the third valve seat 3. During the process of the liquid passing through the pilot flow system, due to the smaller diameter of the damping hole 8, the flow rate of the liquid medium increases after passing through the damping hole 8 (Bernoulli's principle). And from Bernoulli's equation, it can be known that if the flow rate on one side increases (for example, in a small channel), then the pressure on that side will decrease, resulting in different pressures on both sides. Since the flow cross-sections of the first diversion hole 9 and the second diversion hole 10 are basically the same, under their connection effect, the pressure on the left side of the damping hole 8 is the same as the pressure on the upper side of the first sliding shell 7, that is, at this time, the pressure on the lower side of the first sliding shell 7 is greater than the pressure on its upper side. This pressure difference is greater than the elastic potential energy of the spring connected to the first sliding shell 7, and the first sliding shell 7 will drive the connected parts to move upward together, finally removing the occlusion of the circular hole on the fixed sleeve 5, enabling the main liquid medium in the fluid pipeline to enter the pressure relief port 6 through the circular hole on the fixed sleeve 5 and be discharged, further performing a pressure relief operation on the fluid pipeline to improve safety.

[0029] As Figure 2 and Figure 5As shown, the sliding rod 16 is provided with a variable-diameter plug. The diameter of the left side of the variable-diameter plug is larger than that of its right side. The variable-diameter plug of the sliding rod 16 is made of metal. The sliding cavity on the third valve seat 3 is divided into five sections. The left and right ends are used to install the fixed seat 14 and the hexagon nut (existing components). The diameters of the two outer sliding cavities in the middle three sections are the same as the diameter of the left side of the variable-diameter plug, and these two sections are respectively communicated with the third diversion hole 11 and the fourth diversion hole 12. The middle section of the sliding cavity on the third valve seat 3 is a blocking section, and the diameter of the blocking section is the same as the diameter of the right side of the variable-diameter plug. The variable-diameter plug on the sliding rod 16 seals and slides with the blocking section of the sliding cavity on the third valve seat 3, and the two cooperate to form a bending surface to improve the sealing performance between the two. The middle part of the sealing ring 701 is provided with an annular air cavity filled with gas. The fixed sleeve 5 is provided with an annular groove. Under the action of the gas pressure in the annular air cavity of the sealing ring 701, the sealing ring 701 closely adheres to the annular groove on the fixed sleeve 5 to improve the sealing performance between the first sliding shell 7 and the fixed sleeve 5.

[0030] As Figure 4 and Figure 5 shown, the second sliding shell 702 is sealed and slidably provided with the third sliding shell 18. A spring is installed between the third sliding shell 18 and the second sliding shell 702, and the third sliding shell 18 is sealed and slidable with the fixed sleeve 5. The third sliding shell 18, the fixed sleeve 5 and the second sliding shell 702 form an annular chamber one filled with gas. The second sliding shell 702 and the first sliding shell 7 form an annular chamber two filled with gas. The second sliding shell 702 is provided with a through hole for communicating the annular chamber one and the annular chamber two. The first sliding shell 7 is provided with a through hole for communicating the annular chamber two and the annular air cavity on the sealing ring 701. Under the action of the liquid pressure in the fluid pipeline, the pressure acts on the upper part of the cylindrical cavity 4 through the lower part of the cylindrical cavity 4, the damping hole 8, the first diversion hole 9 and the second diversion hole 10. At this time, the pressure acts on the third sliding shell 18, and the third sliding shell 18 moves to compress the gas in the annular chamber one. Subsequently, through the guiding action of the through hole and the annular chamber two, the gas pressure in the sealing ring 701 increases, further improving the sealing performance between the first sliding shell 7 and the fixed sleeve 5.

[0031] Specific working principle: After the device is installed in the fluid pipeline, the fluid pipeline normally transports liquid medium, wherein the liquid medium flows through the lower part of the cylindrical cavity 4 to fill the damping hole 8, the first guide hole 9 and the second guide hole 10 to act on the upper part of the cylindrical cavity 4. At this time, after being filled with liquid medium, since the liquid does not flow, the pressure in the channel is the same. At this time, the first sliding shell 7 remains stationary under the elastic force of the connected spring. When the pressure sensor installed on the fluid pipeline detects that the internal pressure is higher than the set value, The Internet of Things system starts the electromagnetic drive component 15, and the electromagnetic drive component 15 drives the sliding rod 16 to move left and compresses the connected spring. The sliding rod 16 moves left to make its upper reducer break away from the contact with the blocking section on the third valve seat 3. At this time, the liquid medium in the fluid pipeline enters the sliding cavity of the third valve seat 3 through the lower part of the cylindrical cavity 4, the damping hole 8, the first guide hole 9 and the third guide hole 11. The subsequent liquid medium is discharged through the sliding cavity on the third valve seat 3, the fourth guide hole 12, the fifth guide hole 13 and the pressure relief port 6 to perform pilot pre-pressure relief.

[0032] During the pilot pre-pressure relief operation, the diameter of the damping hole 8 is small, and a pressure difference is generated on both sides of the damping hole 8. The left side of the damping hole 8 is connected to the upper part of the first sliding shell 7 through the first guide hole 9 and the second guide hole 10. At this time, the pressure on the left side of the damping hole 8 is the same as the pressure on the upper part of the first sliding shell 7, that is, the pressure on the lower part of the first sliding shell 7 is greater than the pressure on the upper part, and the pressure difference suffered by the first sliding shell 7 is greater than the elastic potential energy of the spring connected to the first sliding shell 7. The liquid medium on the lower side of the first sliding shell 7 squeezes the first sliding shell 7 to move upward under the action of high pressure. At this time, under the tension of the tension spring connected to the second sliding shell 702, the second sliding shell 702 first remains stationary, and the first sliding shell 7 drives the connected parts to move upward and retract into the second sliding shell 702. Finally, the second sliding shell 702 blocks the two sealing rings 701 on the first sliding shell 7, reduces the contact between the sealing ring 701 and the conveyed liquid medium, and prolongs the service life of the sealing ring 701, thereby facilitating the extension of the service life of the device.

[0033] After the second sliding shell 702 covers the two sealing rings 701 on the first sliding shell 7, under the extrusion of the liquid medium, the first sliding shell 7, the sealing ring 701 and the second sliding shell 702 move upward together, so that the second sliding shell 702 releases the covering of the circular hole on the fixed sleeve 5. During the upward movement of the first sliding shell 7, the spring between it and the second valve seat 2 is compressed. At this time, the liquid in the fluid pipeline passes through the lower part of the cylindrical cavity 4 and the circular hole on the fixed sleeve 5 and enters the pressure relief port 6 and is discharged, further relieving the pressure in the fluid pipeline and protecting the safety of the fluid pipeline. When the pressure in the fluid pipeline is restored, the electromagnetic driving member 15 works to control the sliding rod 16 to move rightward and reset. At the same time, under the action of the elastic force of the spring connected to the first sliding shell 7, the first sliding shell 7 drives the second sliding shell 702 to move reversely and reset. When the second sliding shell 702 moves downward to the limit position, the second sliding shell 702 covers the circular hole on the fixed sleeve 5. Subsequently, the second sliding shell 702 remains stationary. Then the first sliding shell 7 continues to move downward, and the tension spring between the first sliding shell 7 and the second sliding shell 702 is stretched. After the first sliding shell 7 moves downward to the lower limit, the device returns to the normal state.

[0034] Embodiment 2: On the basis of Embodiment 1, as Figure 2 , Figure 6 and Figure 7As shown in the figure, it further includes: a first threaded plug 19, threadedly installed on the left part of the second valve seat 2. The second valve seat 2 is provided with a pilot chamber, and the central axis of the first threaded plug 19 coincides with the central axis of the pilot chamber on the second valve seat 2; a cylindrical sleeve 20, fixedly connected to the right side of the first threaded plug 19. A sliding sleeve 201 is arranged in a limited sliding manner on the right part of the cylindrical sleeve 20. There is a hole on the left side of the cylindrical sleeve 20. When the first threaded plug 19 is installed, the hole on the cylindrical sleeve 20 does not block the first diversion hole 9 and the third diversion hole 11. A spring is installed between the sliding sleeve 201 and the cylindrical sleeve 20. Both the sliding sleeve 201 and the cylindrical sleeve 20 are in contact with the second valve seat 2; a second threaded plug 21, threadedly installed on the right part of the second valve seat 2. The second threaded plug 21 is threadedly connected to a threaded rod 22. A plug 23 is arranged in a sliding manner on the left part of the threaded rod 22. A spring is installed between the plug 23 and the threaded rod 22. The threaded connection of the threaded rod 22 is used to change the elastic potential energy of the spring between the threaded rod 22 and the plug 23, facilitating the start-up and pressure relief operation of this device under different pressures. After the assembly of this device is completed, the springs between the sliding sleeve 201 and the cylindrical sleeve 20 and the spring connected to the plug 23 are both in a compressed state. The left side surface of the plug 23 and the sliding sleeve 201 are both made of metal. The left side surface of the plug 23 is set as a conical surface, and the right side surface of the sliding sleeve 201 is set as a conical surface. The conical surface of the plug 23 is in contact with the conical surface of the sliding sleeve 201 to improve the sealing performance between the two. And the contact position between the plug 23 and the sliding sleeve 201 is located between the first diversion hole 9 and the fifth diversion hole 13. The elastic coefficient of the spring between the cylindrical sleeve 20 and the sliding sleeve 201 is less than the elastic coefficient of the spring between the plug 23 and the threaded rod 22.

[0035] As Figure 6 and Figure 7 shown, a sliding plug 24 is arranged in a sealed sliding manner in the middle of the plug 23. The sliding plug 24 is composed of a smooth rod and a plug head. The right part of the sliding plug 24 penetrates through the threaded rod 22 and is slidably connected to it. The cylindrical sleeve 20 is provided with a cylindrical surface, and the plug head of the sliding plug 24 is in sealed sliding contact with the cylindrical surface of the cylindrical sleeve 20; a fixed shell 25 is fixedly connected to the right part of the threaded rod 22. A liquid medium is filled in the fixed shell 25. A sliding plate 26 is arranged in a sealed sliding manner in the fixed shell 25. A tension spring is installed between the sliding plate 26 and the fixed shell 25. The smooth rod of the sliding plug 24 penetrates through the fixed shell 25 and is in sealed sliding contact with it. The right side surface of the smooth rod of the sliding plug 24 is fixedly connected to the sliding plate 26. The sliding plate 26 is provided with six through holes distributed equidistantly in the circumferential direction.

[0036] Specific working principle: when a power outage occurs or the electromagnetic drive component 15 is damaged, the overflow valve cannot actively control the pilot pressure relief operation. However, if the liquid pressure in the fluid pipeline fluctuates, the pressure fluctuation of the liquid medium acts on the left side of the sliding plug 24 through the lower part of the cylindrical cavity 4, the damping hole 8 and the first guide hole 9. As the pressure of the liquid medium increases, the increased pressure of the liquid medium acts on the sliding plug 24, causing the sliding plug 24 to move to the right. However, due to the obstruction of the liquid medium in the fixed shell 25 and the tension of the tension spring connected to the sliding plate 26, the sliding plug 24 slowly moves to the right. The slow movement of the sliding plug 24 buffers the pressure change in the fluid pipeline. When the pressure in the fluid pipeline is restored, under the tension of the tension spring connected to the sliding plate 26, the sliding plate 26 and the sliding plug 24 move to the left and reset.

[0037] When the pressure in the fluid pipeline continues to increase, the sliding plug 24 continues to move rightward to break away from the sealing contact with the cylindrical surface of the cylindrical sleeve 20, and then the liquid medium is injected between the cylindrical sleeve 20 and the sliding sleeve 201. The subsequent liquid medium contacts the sealing plug 23. When the device performs the rightward movement operation of the sliding plug 24 again, the movement of the sliding plug 24 will squeeze the liquid medium between the cylindrical sleeve 20 and the sliding sleeve 201, so that the sliding sleeve 201 moves rightward relative to the cylindrical sleeve 20 and stretches the connected spring. In this process, since the elastic potential energy of the spring connected to the sealing plug 23 is greater than the elastic potential energy of the spring connected to the cylindrical sleeve 20, the pressure value between the sliding sleeve 201 and the cylindrical sleeve 20 in this process cannot squeeze the sliding sleeve 201 and the sealing plug 23 apart.

[0038] After the sliding plug 24 is separated from the seal with the cylindrical surface of the cylindrical sleeve 20, the liquid medium acts on the sealing plug 23 through the cylindrical sleeve 20 and the sliding sleeve 201. When the pressure in the fluid pipeline is higher than the set value, the extrusion force of the liquid medium on the sealing plug 23 is greater than the elastic potential energy of the spring connected to the sealing plug 23. The liquid medium squeezes the sealing plug 23 to move rightward, and the sealing plug 23 moves rightward to release the contact with the sliding sleeve 201. Then the liquid medium is discharged through the gap between the sliding sleeve 201 and the sealing plug 23, the fifth guide hole 13 and the pressure relief port 6, completing the pilot pressure relief operation. The above operation is repeated later to move the first sliding shell 7 and the sealing ring 701 upward to further relieve the pressure of the fluid pipeline. After the pressure relief is completed and the pressure in the fluid pipeline remains stable, the sealing plug 23 moves in the opposite direction and contacts the sliding sleeve 201 under the elastic force of the spring connected to the sealing plug 23. Then the sliding plug 24 and other components move in the opposite direction and reset together, so that the device returns to the initial state. When the pressure fluctuation occurs again in the fluid pipeline, the above operation is repeated.

[0039] During the above process, when there is a short-term pressure fluctuation in the fluid pipeline, the sliding plug 24 moves to the right for buffering. During the buffering operation of the sliding plug 24 in this process, it is avoided that the pressure in the fluid pipeline rises in a short time, triggering the separation of the sealing plug 23 and the sliding sleeve 201, resulting in the discharge of the liquid medium for pressure relief operation. That is, it is avoided that the effective delivery flow rate of this overflow valve decreases and the efficiency drops due to frequent pressure relief.

[0040] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that these embodiments can be changed without departing from the principles and spirit of the present invention.

Claims

1. A relief valve for a fluid pipeline, characterized in that: The invention comprises a first valve seat (1), wherein the first valve seat (1) is provided with a third valve seat (3) via a second valve seat (2), the first valve seat (1) is provided with a cylindrical cavity (4) and a pressure relief port (6) which are interconnected, a fixed sleeve (5) is provided in the cylindrical cavity (4), the fixed sleeve (5) is provided with a circular hole, a first sliding shell (7) is slidably provided in the fixed sleeve (5), a spring is installed between the first sliding shell (7) and the second valve seat (2), a sealing ring (701) is provided on the first sliding shell (7), and the first The sliding shell (7) is slidably provided with a second sliding shell (702) which is sealed and slidable with the fixed sleeve (5); a tension spring is installed between the second sliding shell (702) and the first sliding shell (7); the second sliding shell (702) is used to cover the sealing ring (701); a pilot circulation system for pre-pressure relief is provided on the first valve seat (1); the third valve seat (3) is fixedly connected with an electromagnetic drive component (15) through a fixed seat (14); the electromagnetic drive component (15) is used to control the on-off state of the pilot circulation system.

2. A relief valve for a fluid pipeline according to claim 1, characterized in that: The pilot circulation system comprises a sliding rod (16), the sliding rod (16) is slidably arranged on the fixed seat (14), a spring is installed between the sliding rod (16) and the fixed seat (14), the third valve seat (3) is provided with a sliding cavity, the sliding rod (16) is located in the sliding cavity of the third valve seat (3) and slides in a sealed manner, the electromagnetic drive member (15) is used to control the movement of the sliding rod (16), the first valve seat (1) is provided with a damping hole (8) connected to the cylindrical cavity (4), the first valve seat (1) and the second valve seat (2) are jointly provided with a first guide hole (9) and a fifth guide hole (13), the first valve seat (1) is provided with There is a second flow guide hole (10), wherein the first flow guide hole (9) is connected to the damping hole (8), the second flow guide hole (10) is used to connect the first flow guide hole (9) and the cylindrical cavity (4), the fifth flow guide hole (13) is connected to the pressure relief port (6), the second valve seat (2) and the third valve seat (3) are jointly provided with a third flow guide hole (11) and a fourth flow guide hole (12), the third flow guide hole (11) is connected to the first flow guide hole (9), the fourth flow guide hole (12) is connected to the fifth flow guide hole (13), and the third flow guide hole (11) and the fourth flow guide hole (12) are both connected to the sliding cavity on the third valve seat (3).

3. A relief valve for a fluid pipeline according to claim 2, characterized in that: The sliding rod (16) is provided with a reducing plug, the reducing plug of the sliding rod (16) is made of metal, a section of the sliding cavity on the third valve seat (3) located between the third guide hole (11) and the fourth guide hole (12) is a blocking section, and the reducing plug on the sliding rod (16) slides in a sealed manner with the blocking section of the sliding cavity on the third valve seat (3).

4. A relief valve for a fluid pipeline according to claim 3, characterized in that: An annular air cavity is provided in the middle of the sealing ring (701), and an annular groove is provided on the fixing sleeve (5). The sealing ring (701) is in contact with the annular groove on the fixing sleeve (5).

5. A relief valve for a fluid pipeline according to claim 4, characterized in that: The second sliding shell (702) is sealingly and slidingly provided with a third sliding shell (18), a spring is installed between the third sliding shell (18) and the second sliding shell (702), and the third sliding shell (18) and the fixed sleeve (5) are sealingly and slidingly provided, the third sliding shell (18), the fixed sleeve (5) and the second sliding shell (702) form an annular chamber one filled with gas, the second sliding shell (702) and the first sliding shell (7) form an annular chamber two filled with gas, the second sliding shell (702) is provided with a through hole for connecting the annular chamber one and the annular chamber two, and the first sliding shell (7) is provided with a through hole for connecting the annular chamber two and the annular air cavity on the sealing ring (701).

6. A relief valve for a fluid pipeline according to claim 5, characterized in that: Also included are: a first threaded plug (19) threadably mounted on the second valve seat (2), wherein the second valve seat (2) is provided with a pilot chamber; A cylindrical sleeve (20) is fixedly connected to the first threaded plug (19), the cylindrical sleeve (20) is slidably provided with a sliding sleeve (201), a spring is installed between the sliding sleeve (201) and the cylindrical sleeve (20), and the sliding sleeve (201) and the cylindrical sleeve (20) are both in contact with the second valve seat (2); A second threaded plug (21) is threadedly mounted on the second valve seat (2); the second threaded plug (21) is threadedly provided with a threaded rod (22); the threaded rod (22) is slidably provided with a sealing plug (23); a spring is installed between the sealing plug (23) and the threaded rod (22); the sealing plug (23) is used to seal the sliding sleeve (201); and the contact point between the sealing plug (23) and the sliding sleeve (201) is located between the first guide hole (9) and the fifth guide hole (13).

7. A relief valve for a fluid pipeline according to claim 6, characterized in that: The sealing plug (23) and the sliding sleeve (201) are both made of metal. The sealing plug (23) is provided with a frustum surface, and the sliding sleeve (201) is provided with a frustum surface. The frustum surface of the sealing plug (23) contacts the frustum surface of the sliding sleeve (201) to improve the sealing performance between the two.

8. A relief valve for a fluid pipeline according to claim 7, characterized in that: When the threaded rod (22) is rotated, the elastic potential energy of the spring between the threaded rod (22) and the sealing plug (23) is changed.

9. A relief valve for a fluid pipeline according to claim 8, characterized in that: The sealing plug (23) is provided with a sliding plug (24) in a sealing and sliding manner. The sliding plug (24) penetrates the threaded rod (22) and is slidably connected thereto. The cylindrical sleeve (20) is provided with a cylindrical surface. The sliding plug (24) is sealingly slidable with the cylindrical surface of the cylindrical sleeve (20).

10. A relief valve for a fluid pipeline according to claim 9, characterized in that: The threaded rod (22) is fixedly connected to a fixed shell (25), a liquid medium is filled in the fixed shell (25), a sliding plate (26) is provided in the fixed shell (25) for sealing and sliding, a tension spring is installed between the sliding plate (26) and the fixed shell (25), the sliding plug (24) penetrates the fixed shell (25) and slides in a sealed manner therewith, the sliding plug (24) is fixedly connected to the sliding plate (26), and the sliding plate (26) is provided with a plurality of through holes.

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