An overflow valve for a fluid line

Abstract

The present application relates to the technical field of overflow valve, especially to an overflow valve for fluid pipeline, comprising 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 which are communicated with each other, the cylindrical cavity is provided with a fixed sleeve, the fixed sleeve is provided with a round hole, the fixed sleeve is slidably provided with a first sliding shell, the first sliding shell and the second valve seat are installed with a spring, the first sliding shell is provided with a sealing ring, the first sliding shell is slidably provided with a second sliding shell which is sealedly slid with the fixed sleeve, the second sliding shell and the first sliding shell are installed with a tension spring, and the first valve seat is provided with a pilot flow system. The second sliding shell shields the sealing ring, reduces the contact time of the sealing ring with the flowing medium in the pipeline, prolongs the service life of the sealing ring, and prolongs the service life of the device.

Description

Technical Field

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

[0002] In hydraulic systems formed by fluid pipelines, relief valves are 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, relief valves are mainly divided into direct-acting relief valves, pilot-operated relief valves and electromagnetic relief valves. Among them, electromagnetic relief valves have been widely used in modern hydraulic systems because they can achieve rapid response and precise control through electrical signals. However, in actual applications, electromagnetic relief valves also face some challenges. As the electromagnetic relief valve opens to release pressure, the sealing ring on the sealing plug moves and comes into contact with the flowing medium. Especially during long-term use, the sealing ring on the sealing plug frequently comes into contact with the flowing medium. Affected by the corrosiveness of the conveying medium in the pipeline, the sealing ring's long-term contact with the conveying medium will cause a chemical reaction to occur in the sealing ring, gradually losing its elasticity and reducing its sealing performance, thereby affecting its service life. Summary of the Invention

[0003] In order to overcome the problems mentioned in the above background technology, the present invention provides a relief valve for a fluid pipeline.

[0004] The technical solution is: a relief valve for a fluid pipeline, comprising a first valve seat, a third valve seat being installed on the first valve seat through the second valve seat, the first valve seat being provided with a cylindrical cavity and a pressure relief port which are interconnected, a fixed sleeve being provided in the cylindrical cavity, the fixed sleeve being provided with a circular hole, a first sliding shell being slidingly provided in the fixed sleeve, a spring being installed between the first sliding shell and the second valve seat, a sealing ring being provided on the first sliding shell, a second sliding shell being slidingly provided on the first sliding shell with a sealing and sliding connection with the fixed sleeve, a tension spring being installed between the second sliding shell and the first sliding shell, the second sliding shell being used to cover the sealing ring, a pilot circulation system for pre-pressure relief being provided on the first valve seat, the third valve seat being fixedly connected to an electromagnetic drive component through a fixed seat, and the electromagnetic drive component being used to control the on-off state of the pilot circulation system.

[0005] Preferably, the pilot circulation system includes a sliding rod, which is slidably arranged 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, the sliding rod is located in the sliding cavity of the third valve seat and slides in a sealed manner, the electromagnetic drive component 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 guide hole and a fifth guide hole, the first valve seat is provided with a second guide hole, wherein the first guide hole is communicated with the damping hole, the second guide hole is used to communicate with the first guide hole and the cylindrical cavity, and the fifth guide hole is communicated with the pressure relief port, the second valve seat and the third valve seat are jointly provided with a third guide hole and a fourth guide hole, the third guide hole is communicated with the first guide hole, the fourth guide hole is communicated with the fifth guide hole, and the third guide hole and the fourth guide hole are both communicated with the sliding cavity on the third valve seat.

[0006] Preferably, the sliding rod is provided with a reducing plug, the reducing plug of the sliding rod is made of metal, a section of the sliding cavity on the third valve seat located between the third guide hole and the fourth guide hole is a blocking section, and the reducing plug on the sliding rod slides in a sealed manner 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, an annular groove is provided in the fixing sleeve, and the sealing ring contacts the annular groove on the fixing sleeve.

[0008] Preferably, the second sliding shell is sealingly and slidingly provided with a third sliding shell, a spring is installed between the third sliding shell and the second sliding shell, and the third sliding shell and the fixed sleeve are sealingly and slidingly provided, the third sliding shell, the fixed sleeve and the second sliding shell constitute an annular chamber 1 filled with gas, the second sliding shell and the first sliding shell constitute an annular chamber 2 filled with gas, the second sliding shell is provided with a through hole for connecting the annular chamber 1 and the annular chamber 2, and the first sliding shell is provided with a through hole for connecting the annular chamber 2 and the annular air cavity on the sealing ring.

[0009] Preferably, it also includes:

[0010] a first threaded plug threadably mounted on the second valve seat, wherein the second valve seat is provided with a pilot chamber;

[0011] a cylindrical sleeve fixedly connected to the first threaded plug, wherein a sliding sleeve is slidably provided on 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 mounted on the second valve seat. The second threaded plug is threadedly provided with a threaded rod. A sealing plug is slidably provided 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 point between the sealing plug and the sliding sleeve is located between the first guide hole and the fifth guide hole.

[0013] Preferably, the sealing plug and the sliding sleeve are both made of metal, the sealing plug is provided with a frustum, and the sliding sleeve is provided with a frustum, and the frustum of the sealing plug contacts the frustum of the sliding sleeve to improve the sealing performance therebetween.

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

[0015] Preferably, the sealing plug is provided with a sliding plug for sealing sliding, the sliding plug penetrates the threaded rod and is slidably connected thereto, the cylindrical sleeve is provided with a cylindrical surface, and the sliding plug seals and slides with the cylindrical surface of the cylindrical sleeve.

[0016] Preferably, the threaded rod is fixedly connected to a fixed shell, a liquid medium is filled in the fixed shell, a sliding plate is provided in the fixed shell for sealing and sliding, a tension spring is installed between the sliding plate and the fixed shell, the sliding plug penetrates the fixed shell and slides sealed therewith, the sliding plug is fixedly connected to the sliding plate, and the sliding plate is provided with a plurality of through holes.

[0017] The beneficial effects are as follows: the present invention shields the sealing ring through the second sliding shell, thereby reducing the contact time between the sealing ring and the flowing medium in the pipeline, extending the service life of the sealing ring, and thus extending the service life of the device; utilizing the contact between the sealing plug and the cylindrical sleeve to form a mechanical pressure relief part, ensuring that when the power is cut off or the electromagnetic drive component is damaged, the device can still perform a pressure relief operation to maintain the stability of the pressure in the pipeline; through the relative sliding of the sliding sleeve and the cylindrical sleeve, the pressure fluctuations in the pipeline are buffered, reducing the occurrence of accidental touch-off of the pressure relief operation; through the resistance of the sliding plate moving in the fixed shell, the sealing plug and the sliding sleeve are prevented from separating, thereby preventing short-term pressure fluctuations from causing the device to perform unnecessary pressure relief operations, thereby ensuring the continuity and stability of the liquid medium transportation process. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

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

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

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

[0025] In the figure marks: 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 flow guide hole, 10-second flow guide hole, 11-third flow guide hole, 12-fourth flow guide hole, 13-fifth flow guide hole, 14-fixed seat, 15-electromagnetic drive component, 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 DESCRIPTION

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

[0027] Example 1: A relief valve for a fluid pipeline, such 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 the fluid pipeline, the pressure relief port 6 is connected to a collection barrel, and the collection barrel is used to collect the liquid medium discharged during pressure relief, a fixed sleeve 5 is placed in the cylindrical cavity 4, the fixed sleeve 5 is used to separate the cylindrical cavity 4 and the pressure relief port 6, and three rubber rings are provided on the fixed sleeve 5, two of which are located at the upper part of the fixed sleeve 5, and one rubber ring is located at the lower part of the fixed sleeve 5, for improving the sealing between the fixed sleeve 5 and the first valve seat 1, 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 slidingly provided 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 provided at the lower part of the first sliding shell 7. A second sliding shell 702 is slidingly provided on 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 provided on the second sliding shell 702. The second sliding shell 702 and the first sliding shell are in a sealed manner with each other. A tension spring is installed between the shells 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 closed state of the relief valve, the second sliding shell 702 is used to seal 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. A 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 drive component 15 is bolted to the right side of the fixing seat 14. The electromagnetic drive component 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 drive component 15 through the Internet of Things system. When the pressure sensor detects that the pressure in the fluid pipeline is too high, the electromagnetic drive component 15 is controlled to start through 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 circulation system includes a sliding rod 16, which is slidably arranged on the fixed seat 14, and a spring is installed between the sliding rod 16 and the fixed seat 14. 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 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 spring between the sliding rod 16 and the fixed seat 14 is used to make the sliding rod 16 initially block the pilot circulation system. The diameter of the damping hole 8 is smaller than that of other circulation channels. The first valve The seat 1 is provided with a damping hole 8, which is 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, that is, the first guide hole 9 and the fifth guide hole 13 are composed of two sections of channels. The first valve seat 1 is provided with a second guide hole 10, wherein the first guide hole 9 is connected to the damping hole 8, and the second guide hole 10 is used to connect the first guide hole 9 and the cylindrical cavity 4, and the second guide hole 10 is located above the cylindrical cavity 4. The fifth guide hole 13 is connected to the pressure relief port 6, and the second valve seat 2 and the third valve seat 3 are jointly provided with a third guide hole 11 and the fourth guide hole 12, the third guide hole 11 is connected to the first guide hole 9, the fourth guide hole 12 is connected to the fifth guide hole 13, and the third guide hole 11 and the fourth guide hole 12 are both connected to the sliding cavity on the third valve seat 3. In the process of liquid passing through the pilot circulation system, due to the small diameter of the damping hole 8, the flow rate of the liquid medium is accelerated after passing through the damping hole 8 (Bernoulli principle). It can be seen from the Bernoulli equation that if the flow rate on one side increases (for example, in a small channel), the pressure on that side will decrease, resulting in different pressures on both sides. Since the first guide hole 9 and The flow cross-sections of the second guide holes 10 are substantially the same. Under the effect of their connection, 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 the upper side thereof. This pressure difference is greater than the elastic potential energy of the spring connected to the first sliding shell 7. The first sliding shell 7 will drive the connected parts to move upward together, and eventually remove the obstruction of the circular hole on the fixing sleeve 5, so that the main liquid medium in the fluid pipeline enters the pressure relief port 6 through the circular hole on the fixing sleeve 5 and is discharged, further performing a pressure relief operation on the fluid pipeline and improving safety.

[0029] like Figure 2 and Figure 5As shown, the sliding rod 16 is provided with a reducing plug, the left diameter of the reducing plug being larger than the right diameter. The reducing plug of the sliding rod 16 is made of metal. The sliding cavity on the third valve seat 3 is divided into five sections, of which the left and right ends are used to install the fixed seat 14 and the hexagonal nut (existing parts). The diameters of the two outer sliding cavities of the middle three sections are the same as the diameter of the left side of the reducing plug, and the two sections are connected to the third guide hole 11 and the fourth guide hole 12 respectively. The middle section of the sliding cavity on the third valve seat 3 is a blocking section, the diameter of which is the same as the diameter of the right side of the reducing plug. The reducing plug on the sliding rod 16 and the blocking section of the sliding cavity on the third valve seat 3 are sealed and slidable, and the two cooperate to form a bent surface for improving the sealing between the two. An annular air cavity is provided in the middle of the sealing ring 701, which is filled with gas. The fixing 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 is tightly attached to the annular groove of the fixing sleeve 5, thereby improving the sealing between the first sliding shell 7 and the fixing sleeve 5.

[0030] like Figure 4 and Figure 5 As shown, the second sliding shell 702 is provided with a third sliding shell 18 for sealing and sliding. 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 sealed and slid. The third sliding shell 18, the fixed sleeve 5 and the second sliding shell 702 form an annular chamber 1 filled with gas, and the second sliding shell 702 and the first sliding shell 7 form an annular chamber 2 filled with gas. The second sliding shell 702 is provided with a through hole for communicating the annular chamber 1 and the annular chamber 2, and the first sliding shell 7 is provided with a through hole for communicating the annular chamber 1 and the annular chamber 2. The through hole connecting the annular chamber 2 and the annular air cavity on the sealing ring 701 is affected by the liquid pressure in the fluid pipeline. The pressure acts on the upper part of the cylindrical chamber 4 through the lower part of the cylindrical chamber 4, the damping hole 8, the first guide hole 9 and the second guide 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 1. Subsequently, the gas pressure in the sealing ring 701 is increased through the guiding effect of the through hole and the annular chamber 2, thereby further improving the sealing 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, and the liquid medium flows through the lower part of the cylindrical cavity 4 filled with the damping hole 8, the first flow guide hole 9 and the second flow guide hole 10 to act on the upper part of the cylindrical cavity 4. At this time, after being filled with liquid medium, the pressure in the channel is the same because the liquid does not flow. At this time, the first sliding shell 7 remains static under the elastic force of the connected spring. When the pressure sensor installed on the fluid pipeline detects that the pressure in it is higher than the set value, the Internet of Things system starts the electromagnetic drive 15. The electromagnetic drive 15 works to drive the sliding rod 16 to move left and compress the connected spring. The left movement of the sliding rod 16 makes the variable diameter plug on it disengage 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 flow guide hole 9 and the third flow guide hole 11. The subsequent liquid medium is discharged through the sliding cavity on the third valve seat 3, the fourth flow guide hole 12, the fifth flow guide hole 13 and the pressure relief port 6, and the pilot type pre-pressure relief is carried out.

[0032] During the pilot type pre-pressure relief operation, the diameter of the damping hole 8 is small, and at this time, a pressure difference is generated on both sides of the damping hole 8. The left side of the damping hole 8 communicates with the upper part of the first sliding shell 7 through the first flow guide hole 9 and the second flow guide hole 10. At this time, the pressure on the left side of the damping hole 8 and the pressure on the upper part of the first sliding shell 7 are the same, that is, at this time, the pressure on the lower part of the first sliding shell 7 is greater than that on the upper part, and at this time, the pressure difference that the first sliding shell 7 receives 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 is extruded to move the first sliding shell 7 upward under the action of high pressure. At this time, the second sliding shell 702 is first kept static under the action of the tension of the tension spring connected to the second sliding shell 702. The first sliding shell 7 drives the connected parts to move upward and shrink 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 rings 701 and the transported liquid medium, prolongs the service life of the sealing rings 701, and thus prolongs the service life of the device.

[0033] After the second sliding shell 702 blocks the two sealing rings 701 on the first sliding shell 7, the first sliding shell 7, the sealing ring 701 and the second sliding shell 702 move upward together under the squeeze of the liquid medium, so that the second sliding shell 702 releases the obstruction of the circular hole on the fixed sleeve 5. The first sliding shell 7 compresses the spring between it and the second valve seat 2 during the upward movement. 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 to protect the safety of the fluid pipeline. After the pressure in the body pipeline is restored, the electromagnetic drive part 15 works to control the sliding rod 16 to move right and reset. At the same time, under 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 in the opposite direction and reset. When the second sliding shell 702 moves down to the limit position, the second sliding shell 702 blocks the circular hole on the fixed sleeve 5. Subsequently, the second sliding shell 702 remains stationary, and then the first sliding shell 7 continues to move down. The tension spring between the first sliding shell 7 and the second sliding shell 702 is stretched. After the first sliding shell 7 moves down to the lower limit, the device returns to normal.

[0034] Example 2: Based on Example 1, Figure 2 、 Figure 6 and Figure 7As shown, it also includes: a first threaded plug 19, which is threadedly installed on the left part of the second valve seat 2, and the second valve seat 2 is provided with a pilot chamber. 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, which is fixed to the right side of the first threaded plug 19, and the right part of the cylindrical sleeve 20 is provided with a sliding sleeve 201 for limiting sliding. A hole is provided 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 guide hole 9 and the third guide hole 11. 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, which is threadedly installed on the right part of the second valve seat 2, and the second threaded plug 21 is threadedly connected to a threaded rod 22. A sealing plug 23 is slidingly provided on the left part of the threaded rod 22, and the sealing plug 23 is connected to the threaded rod 22. A spring is installed between the two ends of the sleeve 20. 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 sealing plug 23, so that the device can be started and relieved under different pressures. After the device is assembled, the spring between the sliding sleeve 201 and the cylindrical sleeve 20 and the spring connected to the sealing plug 23 are both in a compressed state. The left side of the sealing plug 23 and the sliding sleeve 201 are both made of metal. The left side of the sealing plug 23 is set as a frustum, and the right side of the sliding sleeve 201 is set as a frustum. The frustum of the sealing plug 23 contacts the frustum of the sliding sleeve 201 to improve the sealing between the two. 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. The elastic coefficient of the spring between the cylindrical sleeve 20 and the sliding sleeve 201 is smaller than the elastic coefficient of the spring between the sealing plug 23 and the threaded rod 22.

[0035] like Figure 6 and Figure 7 As shown, a sliding plug 24 is provided in the middle of the sealing plug 23 for sealing sliding. The sliding plug 24 consists of a polished rod and a plug. The right part of 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 plug on the sliding plug 24 slides sealingly with the cylindrical surface of the cylindrical sleeve 20. The right part of the threaded rod 22 is fixedly connected to a fixed shell 25. The fixed shell 25 is filled with a liquid medium. A sliding plate 26 is provided in the fixed shell 25 for sealing sliding. A tension spring is installed between the sliding plate 26 and the fixed shell 25. The polished rod of the sliding plug 24 penetrates the fixed shell 25 and slides sealingly therewith. The right side of the polished rod on the sliding plug 24 is fixedly connected to the sliding plate 26. The sliding plate 26 is provided with six through holes equidistantly distributed circumferentially.

[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 recovers, 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 rise, the sliding plug 24 continues to move rightward and breaks away from the sealing contact with the cylindrical surface of the cylindrical sleeve 20. Subsequently, the liquid medium is injected between the cylindrical sleeve 20 and the sliding sleeve 201. Subsequently, the 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, causing the sliding sleeve 201 to move rightward relative to the cylindrical sleeve 20 and stretch the connected spring. During 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 is unable to squeeze the sliding sleeve 201 and the sealing plug 23 apart.

[0038] After the sliding plug 24 is released 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 line exceeds the set value, the extrusion force of the liquid medium on the sealing plug 23 exceeds the elastic potential energy of the spring connected to the sealing plug 23. The liquid medium squeezes the sealing plug 23 to the right, and the sealing plug 23 moves rightward, breaking contact with the sliding sleeve 201. The liquid medium is then 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 then repeated, causing the first sliding housing 7 and the sealing ring 701 to move upward, further relieving the pressure in the fluid line. After the pressure relief is completed and the pressure in the fluid line remains stable, the sealing plug 23 is reversed by the elastic force of the spring connected to the sealing plug 23, contacting the sliding sleeve 201. The sliding plug 24 and other components then reverse and reset, restoring the device to its initial state. If the pressure in the fluid line fluctuates again, the above operation is repeated.

[0039] In the above process, when the pressure in the fluid pipeline fluctuates briefly, the sliding plug 24 moves to the right for buffering. The buffering operation of the sliding plug 24 in this process prevents the short-term pressure increase in the fluid pipeline from 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. In other words, it prevents the overflow valve from reducing the effective delivery flow rate and efficiency due to frequent pressure relief.

[0040] While embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the 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) through 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), a second sliding shell (702) which is slidably provided on the first sliding shell (7) and 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), a pilot flow 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), and the electromagnetic drive component (15) works to control the on-off state of the pilot flow system; An annular air cavity is provided in the middle of the sealing ring (701), an annular groove is provided on the fixing sleeve (5), and the sealing ring (701) is in contact with the annular groove on the fixing sleeve (5); The second sliding shell (702) is provided with a third sliding shell (18) for sealing and sliding, 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 sealed and slidable, the third sliding shell (18), the fixed sleeve (5) and the second sliding shell (702) form an annular chamber 1 filled with gas, the second sliding shell (702) and the first sliding shell (7) form an annular chamber 2 filled with gas, the second sliding shell (702) is provided with a through hole for communicating between the annular chamber 1 and the annular chamber 2, and the first sliding shell (7) is provided with a through hole for communicating between the annular chamber 2 and the annular air cavity on the sealing ring (701); In the blocked state, the second sliding shell (702) is used to block the circular hole on the fixed sleeve (5); in the open state, the first sliding shell (7) is retracted into the second sliding shell (702), and the second sliding shell (702) blocks the sealing ring (701).

2. The overflow valve for a fluid pipeline according to claim 1, characterized in that: The pilot flow system includes 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. The overflow valve for a fluid pipeline according to claim 2, characterized in that: The sliding rod (16) is provided with a reducing plug, and 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. 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. The overflow valve for a fluid pipeline according to claim 3, 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) fixedly connected to the first threaded plug (19); a sliding sleeve (201) being slidably provided on the cylindrical sleeve (20); a spring being installed between the sliding sleeve (201) and the cylindrical sleeve (20); and both the sliding sleeve (201) and the cylindrical sleeve (20) being 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).

5. The overflow valve for a fluid pipeline according to claim 4, 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, and the sliding sleeve (201) is provided with a frustum. The frustum of the sealing plug (23) contacts the frustum of the sliding sleeve (201) to improve the sealing performance between the two.

6. The overflow valve for a fluid pipeline according to claim 5, 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.

7. The overflow valve for a fluid pipeline according to claim 6, characterized in that: The sealing plug (23) is provided with a sliding plug (24) for sealing and sliding. 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) seals and slides with the cylindrical surface of the cylindrical sleeve (20).

8. The overflow valve for a fluid pipeline according to claim 7, 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 with the fixed shell (25) in a sealed manner, the sliding plug (24) and the sliding plate (26) are fixedly connected, and the sliding plate (26) is provided with a plurality of through holes.

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