CN219639609U - Back pressure valve - Google Patents

Abstract

The utility model provides a back pressure valve, which comprises a valve seat assembly, a valve core assembly and a valve body assembly, wherein an inflow passage, an outflow passage and a flow control groove are formed in the valve seat assembly, and a valve port is formed at the joint of the outflow passage and the flow control groove; the valve body component is arranged in the flow control groove and is externally sleeved with a coil; the valve core assembly is arranged in the valve body assembly and comprises a valve core, a first elastic piece, a second elastic piece and an armature, the valve core is connected with the armature through the first elastic piece, the valve core can close the valve port under the action of elastic force of the first elastic piece, the armature is movably arranged in the valve body assembly through the second elastic piece, the coil is used for driving the armature to overcome the elastic force of the second elastic piece through a magnetic field to move along the direction away from the valve port, so that the deformation of the first elastic piece when the valve core closes the valve port is changed, and the rigidity of the second elastic piece is larger than that of the first elastic piece. According to the utility model, the back pressure value is changed by adjusting the coil current, so that the back pressure value adjusting efficiency and response speed are improved.

Description

Back pressure valve

Technical Field

The utility model relates to the field of semiconductor process equipment, in particular to a back pressure valve.

Background

The back pressure valve (Back Pressure Valve) is widely applied to controlling the flow of various types of fluids such as air, water, steam, various corrosive media, slurry, oil products, liquid metal, radioactive media and the like, and the inside of the back pressure valve often comprises an elastic piece, the valve core is pressed on the valve port through the elastic piece, the valve core can be jacked up by overcoming the elastic force of the elastic piece when the fluid pressure exceeds a back pressure value, so that the fluid passes through the back pressure valve, and the valve core cannot be jacked up and passes through the back pressure valve when the fluid pressure does not reach the back pressure value, thereby achieving the aim of regulation.

The back pressure value of the existing back pressure valve is generally not adjustable, the application range corresponding to the back pressure value is small, and when the back pressure valve is used, the corresponding back pressure valve is often required to be selected and installed after the back pressure value required by a pipeline is calculated. The back pressure valve back pressure value of partial structure is adjustable, however when this back pressure valve carries out back pressure value and adjusts, the staff need adjust inside adjusting spring through rotating the handle to because the friction between inside gland isotructure and the adjusting spring is great, lead to adjusting spring to rotate hard, and adjustment efficiency is low and the precision is relatively poor. The back pressure value cannot be accurately adjusted, so that the normal use of the pipeline is greatly hindered, the working progress of the pipeline is affected, and the existing adjustable back pressure valve is mostly applied to liquid and cannot meet the use environments such as gas environments and the like requiring high sealing performance.

Therefore, how to provide a back pressure valve capable of accurately adjusting the back pressure value is a technical problem to be solved in the art.

Disclosure of Invention

The utility model aims to provide a back pressure valve, and the back pressure value of the back pressure valve can be accurately adjusted.

In order to achieve the above object, the present utility model provides a back pressure valve comprising a valve seat assembly, a valve core assembly and a valve body assembly, wherein,

an inflow passage, an outflow passage and a flow control groove communicated with the inflow passage and the outflow passage are formed in the valve seat assembly, and a valve port is formed at the joint of the outflow passage and the flow control groove;

the valve body assembly is arranged in the flow control groove and is in sealing connection with the valve seat assembly, and a coil is sleeved outside the valve body assembly;

the valve core assembly is arranged in the valve body assembly, the valve core assembly comprises a valve core, a first elastic piece, a second elastic piece and an armature, the valve core is connected with the armature through the first elastic piece, the valve core can close the valve port under the action of elastic force of the first elastic piece, the armature is movably arranged in the valve body assembly through the second elastic piece, the coil is used for driving the armature to overcome the elastic force of the second elastic piece through a magnetic field and move along the direction away from the valve port so as to change the deformation quantity of the first elastic piece when the valve core closes the valve port, and the rigidity of the second elastic piece is larger than that of the first elastic piece.

Optionally, the valve body subassembly includes valve body and magnetic seat, the fixed setting of magnetic seat is in the accuse chute and with disk seat subassembly sealing connection, the accommodation blind hole has been seted up to the bottom of valve body, the bottom of magnetic seat is formed with first holding tank, the bottom of first holding tank be formed with the coaxial dodge the through-hole of first holding tank, first elastic component the second elastic component with the case all sets up in the first holding tank, the top of armature passes dodge the through-hole just armature can be followed business turn over the direction motion of accommodation blind hole.

Optionally, the back pressure valve further includes a locking ring, the second elastic element is a reed, the center of the reed is fixedly connected with the bottom end of the armature, the locking ring is fixedly arranged in the first accommodating groove, and the edge of the reed is pressed at the bottom of the first accommodating groove.

Optionally, a fixing hole is formed in the center of the second elastic element, the back pressure valve further comprises a support, a threaded mounting column is arranged at the top of the support, a threaded hole is formed in the bottom of the armature, the threaded mounting column penetrates through the fixing hole of the second elastic element and is screwed into the threaded hole, the center of the reed is fixedly connected with the bottom end of the armature, and the first elastic element is arranged between the support and the valve core.

Optionally, the back pressure valve further comprises a clamping seat, the bottom of the clamping seat is fixedly connected with the top of the valve core, the valve core is made of elastic materials, and the first elastic piece is arranged between the pad support and the clamping seat.

Optionally, the first elastic element is a spring, a first annular fixing groove is formed at the bottom of the pad support, a second annular fixing groove is formed at the top of the clamping seat, the top end of the first elastic element is arranged in the first annular fixing groove, and the bottom end of the first elastic element is arranged in the second annular fixing groove.

Optionally, the valve body includes magnetic head and guide cylinder, the guide cylinder is connected the magnetic head with between the magnetic seat, the bottom of magnetic head is formed with dodges the blind hole, dodge the blind hole with the hole intercommunication of guide cylinder forms hold the blind hole.

Optionally, the back pressure valve further comprises a pressing block, the pressing block is provided with a containing through hole penetrating through the pressing block along the vertical direction, a second annular flange surrounding the axis of the containing through hole is formed on the inner wall of the containing through hole, and an annular mounting groove coaxial with the first containing groove and connected with the outer side wall of the magnetic seat is further formed at the top of the magnetic seat; the magnetic seat is accommodated in the accommodating through hole, the second annular flange of the pressing block is accommodated in the annular mounting groove, and the bottom of the pressing block is fixedly connected with the top of the valve seat assembly so as to fixedly connect the magnetic seat with the valve seat assembly.

Optionally, the backpressure valve further comprises a valve cover and a mounting nut, the valve cover is sleeved outside the coil and the pressing block, a mounting through hole is formed in the top of the valve cover, a thread section is formed in the top of the magnetic conduction head, an external thread is formed on the outer wall of the thread section, and the thread section penetrates out of the mounting through hole to the upper portion of the valve cover and is in threaded fit connection with the mounting nut.

Optionally, the valve seat assembly includes a valve seat body and an adapter, the inflow passage, the outflow passage and the flow control groove are all formed in the valve seat body, a valve port installation groove is formed at the bottom of the flow control groove corresponding to the connection position of the outflow passage and the flow control groove, the adapter is installed in the valve port installation groove, an overflow hole is formed in the adapter, the flow control groove is communicated with the outflow passage through the overflow hole, and the overflow hole is formed as the valve port corresponding to an opening at one side of the flow control groove.

In the utility model, the lower pressure of the first elastic piece on the valve core changes along with the change of the distance between the armature and the valve port when the valve core closes the valve port, so that the lifting height of the armature can be controlled by adjusting the coil current, and the gas pressure required by the gas jacking up the valve core and flowing into the outflow passage is changed, namely the back pressure value of the back pressure valve is changed by adjusting the coil current, and the back pressure value adjusting efficiency and response speed of the back pressure valve are improved.

In addition, the back pressure valve provided by the utility model can adjust the back pressure value of the back pressure valve by only changing the current in the coil in the use process, and mechanical and manual adjustment of parts in the back pressure valve is not needed in the process, so that the collision and friction between parts are reduced, the service life of the back pressure valve is prolonged, and the cost of a semiconductor process is further reduced.

Drawings

The accompanying drawings are included to provide a further understanding of the utility model, and are incorporated in and constitute a part of this specification, illustrate the utility model and together with the description serve to explain, without limitation, the utility model. In the drawings:

FIG. 1 is a schematic diagram of a back pressure valve according to an embodiment of the present utility model;

FIG. 2 is a schematic exploded view of a back pressure valve according to an embodiment of the present utility model;

FIG. 3 is a schematic view of a portion of a back pressure valve according to an embodiment of the present utility model;

FIG. 4 is a schematic view of a portion of a back pressure valve according to an embodiment of the present utility model;

fig. 5 is a schematic view of a portion of a back pressure valve according to an embodiment of the present utility model.

Reference numerals illustrate:

100: adaptor 200: valve core

300: valve seat body 310: inflow passage

320: outflow passage 410: first elastic piece

420: the second elastic member 430: pad support

431: threaded mounting post 432: first annular fixing groove

440: card base 441: second annular fixing groove

510: armature 520: coil

600: valve body assembly 601: accommodating blind hole

611: magnetic head 612: guide cylinder

613: first annular flange 620: magnetic base

710: locking ring 720: briquetting machine

721: second annular flange 810: valve cover

820: mounting nut

Detailed Description

The following describes specific embodiments of the present utility model in detail with reference to the drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the utility model, are not intended to limit the utility model.

In order to solve the above technical problems, the present utility model provides a back pressure valve, as shown in fig. 1 and 2, which comprises a valve seat assembly, a valve core assembly and a valve body assembly 600, wherein an inflow passage 310, an outflow passage 320 and a flow control groove a communicating with the inflow passage 310 and the outflow passage 320 are provided in the valve seat assembly, a valve port B is formed at the connection part of the outflow passage 320 and the flow control groove a, the valve body assembly 600 is installed in the flow control groove a and is in sealing connection with the valve seat assembly, and a coil 520 is sleeved outside the valve body assembly 600.

The valve core assembly is arranged in the valve body assembly 600, the valve core assembly comprises a valve core 200, a first elastic piece 410, a second elastic piece 420 and an armature 510, the valve core 200 is connected with the armature 510 through the first elastic piece 410, the valve core 200 can seal a valve port B under the action of elastic force of the first elastic piece 410, the armature 510 is movably arranged in the valve body assembly 600 through the second elastic piece 420, a coil 520 is used for driving the armature 510 to overcome the elastic force of the second elastic piece 420 through a magnetic field to move along the direction away from the valve port B so as to change the deformation quantity of the first elastic piece 410 when the valve core 200 seals the valve port B, and the rigidity of the second elastic piece 420 is larger than that of the first elastic piece 410.

In the present utility model, the inflow path 310 communicates with the flow control groove a, and the outflow path 320 communicates with the flow control groove a through the valve port B, so that fluid (e.g., gas) in the environment in which the inflow path 310 communicates can enter the flow control groove a, and when the upward pressure generated by the gas pressure acting on the bottom surface of the valve cartridge 200 is greater than the downward pressure of the first elastic member 410 on the valve cartridge 200, the gas can jack up the valve cartridge 200 and flow into the outflow path 320 (through the valve port B).

The coil 520 is sleeved outside the valve body assembly 600 to form an electromagnet, when the coil 520 generates a magnetic field to drive the armature 510 to rise, the armature 510 overcomes the elastic force of the second elastic member 420 to be far away from the valve port B (and moves until the elastic force generated by deformation of the second elastic member 420 is enough to balance with electromagnetic force), so that the state of the first elastic member 410 when the valve core 200 closes the valve port B is prolonged compared with that before the electromagnet works, the downward pressure of the first elastic member 410 on the valve core 200 when the valve core 200 closes the valve port B is reduced, and the gas pressure required by the gas jacking up the valve core 200 and flowing into the outflow passage 320 is smaller, namely, the back pressure value of the back pressure valve is reduced compared with that before the electromagnet works.

In the present utility model, when the valve core 200 closes the valve port B, the downward pressure of the first elastic member 410 on the valve core 200 changes along with the distance between the armature 510 and the valve port B, so that the lifting height of the armature 510 can be controlled by adjusting the current of the coil 520, and further the gas pressure required by the gas to lift the valve core 200 and flow into the outflow channel 320 is changed, that is, the back pressure value of the back pressure valve is changed by adjusting the current of the coil, so that the back pressure value adjusting efficiency and response speed of the back pressure valve are improved.

In addition, the back pressure valve provided by the utility model can adjust the back pressure value of the back pressure valve by only changing the current in the coil 520 in the use process, and mechanical and manual adjustment of parts in the back pressure valve is not needed in the process, so that the collision and friction between parts are reduced, the service life of the back pressure valve is prolonged, and the cost of a semiconductor process is further reduced.

It should be noted that, since the stiffness of the second elastic member 420 is greater than that of the first elastic member 410, it is difficult to push the second elastic member 420 to generate elastic deformation when the gas lifts the valve core 200, and the downward pressure of the first elastic member 410 on the valve core 200 when the valve core 200 closes the valve port B may be regarded as being related to the armature 510 only.

As an alternative embodiment of the present utility model, as shown in fig. 1 and 5, a valve body assembly 600 includes a valve body 610 and a magnetic seat 620, the magnetic seat 620 is fixedly disposed in a flow control groove and is in sealing connection with the valve seat assembly, a receiving blind hole 601 is formed at the bottom of the valve body 610, a first receiving groove is formed at the bottom of the magnetic seat 620, a through hole coaxial with the first receiving groove is formed at the bottom of the first receiving groove, a first elastic member 410, a second elastic member 420 and a valve core 200 are disposed in the first receiving groove, the top end of the armature 510 passes through the through hole, and the armature 510 can move along a direction of entering and exiting the receiving blind hole 601.

As an alternative embodiment of the present utility model, as shown in fig. 1, the valve seat assembly includes a valve seat body 300 and an adapter 100, an inflow passage 310, an outflow passage 320 and a flow control groove a are formed in the valve seat body 300, a valve port installation groove is formed at the bottom of the flow control groove a corresponding to the connection position of the outflow passage 320 and the flow control groove a, the adapter 100 is installed in the valve port installation groove, an overflow hole 110 is formed in the adapter 100, the flow control groove a communicates with the outflow passage 320 through the overflow hole 110, and an opening of the overflow hole 110 corresponding to one side of the flow control groove a is formed as a valve port B.

As an alternative embodiment of the present utility model, as shown in fig. 1 and 2, the back pressure valve further includes a locking ring 710, the second elastic member 420 is a spring, the center of the spring is fixedly connected with the bottom end of the armature 510, and the locking ring 710 is fixedly disposed in the first receiving groove and presses the edge of the spring against the groove bottom of the first receiving groove.

In order to facilitate the assembly and disassembly of the locking ring 710 and the second elastic member 420 (reed), as a preferred embodiment of the present utility model, an internal thread is formed on the inner wall of the first receiving groove, an external thread is formed on the locking ring 710, and the locking ring 710 is fixedly disposed in the first receiving groove by a screw-coupling action between the external thread and the internal thread.

As an alternative embodiment of the present utility model, as shown in fig. 1, 4 and 5, a fixing hole is formed at the center of the second elastic member 420, the back pressure valve further includes a support 430, a threaded mounting post 431 is formed at the top of the support 430, a threaded hole is formed at the bottom of the armature 510, the threaded mounting post 431 passes through the fixing hole of the second elastic member 420 and is screwed into the threaded hole to fixedly connect the center of the reed with the bottom end of the armature 510, and the first elastic member 410 is disposed between the support 430 and the valve core 200.

As a preferred embodiment of the present utility model, as shown in fig. 1, 3, 4 and 5, the back pressure valve further includes a clamping seat 440, the bottom of the clamping seat 440 is fixedly connected to the top of the valve core 200, the valve core 200 is made of an elastic material, and the first elastic member 410 is disposed between the pad 430 and the clamping seat 440.

In the embodiment of the utility model, the material of the valve core 200 is an elastic material, so that the sealing performance of the valve core 200 to the adapter 100 is improved by the contact between the elastic bottom surface of the valve core 200 and the top of the adapter 100, and meanwhile, the top surface of the valve core 200 is connected with the first elastic element 410 through the rigid clamping seat 440, thereby avoiding the concentration of internal stress of the valve core 200 and ensuring the integrity of the valve core 200.

As an alternative embodiment of the present utility model, the valve core 200 is made of rubber.

As an alternative embodiment of the present utility model, the top of the cartridge 200 is adhesively attached to the bottom of the cartridge 440.

To ensure the accuracy of the adjustment of the back pressure threshold, as a preferred embodiment of the present utility model, as shown in fig. 1 and 3, the first elastic member 410 is a spring, the bottom of the pad 430 is formed with a first annular fixing groove 432, the top of the holder 440 is provided with a second annular fixing groove 441, the top of the first elastic member 410 is disposed in the first annular fixing groove 432, and the bottom of the first elastic member 410 is disposed in the second annular fixing groove 441.

In the embodiment of the utility model, the bottom of the pad support 430 is formed with the first annular fixing groove 432, the top of the clamping seat 440 is provided with the second annular fixing groove 441, and two ends of the first elastic element 410 (spring) are respectively inserted into the two annular fixing grooves, so that the limit of the first elastic element 410 in the horizontal direction is realized, the first elastic element 410 is ensured to stretch only in the vertical direction and not to twist or pop out in the horizontal direction, the accuracy of applying pressure to the valve core 200 when the armature 510 is positioned at the corresponding height is ensured, and the accuracy of adjusting the back pressure value of the back pressure valve is further ensured.

As a preferred embodiment of the present utility model, as shown in fig. 1 and 5, the valve body 610 includes a magnetic head 611 and a guide cylinder 612, the guide cylinder 612 is connected between the magnetic head 611 and the magnetic seat 620, a avoidance blind hole is formed at the bottom of the magnetic head 611, and the avoidance blind hole is communicated with an inner hole of the guide cylinder 612 to form a receiving blind hole 601.

In a preferred embodiment of the present utility model, the magnetic head 611 and the magnetic base 620 are made of soft magnetic materials, and the guide cylinder 612 is made of metal materials.

In the embodiment of the utility model, the valve body assembly 600 includes a magnetic guiding head 611, a guiding cylinder 612 and a magnetic seat 620, wherein the magnetic guiding head 611 and the magnetic seat 620 are made of soft magnetic materials, and the guiding cylinder 612 is made of metal materials, so that the guiding cylinder 612 made of metal materials is utilized to provide guiding function for the armature 510 while ensuring the magnetic field direction through the cooperation of the magnetic guiding head 611 made of soft magnetic materials and the magnetic seat 620, thereby reducing the friction force between the armature 510 and the inner wall of the accommodating blind hole 601 and further ensuring the accuracy of back pressure valve back pressure value adjustment.

As an alternative embodiment of the present utility model, the armature 510 is made of soft magnetic material.

As an alternative embodiment of the present utility model, as shown in fig. 1 and 5, the bottom end of the guide cylinder 612 has a first annular flange 613 surrounding the outer wall of the guide cylinder 612, and the top of the magnetic seat 620 is further formed with a second receiving groove coaxial with the first receiving groove, and the first annular flange 613 is fixedly disposed in the second receiving groove.

As an alternative embodiment of the present utility model, the magnetic head 611 is welded to the guide cylinder 612, and the guide cylinder 612 is welded to the magnet holder 620.

As an alternative embodiment of the present utility model, as shown in fig. 1, the back pressure valve further includes a pressing block 720, the pressing block 720 having a receiving through hole penetrating the pressing block 720 in a vertical direction, a second annular flange 721 formed on an inner wall of the receiving through hole to surround an axis of the receiving through hole, and an annular mounting groove coaxial with the first receiving groove and connected to an outer side wall of the magnetic seat 620 being further formed at a top of the magnetic seat 620; the magnetic seat 620 is received in the receiving through hole, and the second annular flange 721 of the pressing block 720 is received in the annular mounting groove, and the bottom of the pressing block 720 is fixedly connected with the top of the valve seat assembly to fixedly connect the magnetic seat 620 with the valve seat assembly.

As a preferred embodiment of the present utility model, as shown in fig. 1, the back pressure valve further comprises a valve housing 810 and a mounting nut 820, the valve housing 810 is sleeved outside the coil 520 and the pressing block 720, the top of the valve housing 810 is provided with a mounting through hole, the top of the magnetic head 611 is provided with a threaded section, an external thread is formed on the outer wall of the threaded section, and the threaded section passes out from the mounting through hole to above the valve housing 810 and is in threaded fit connection with the mounting nut 820.

In the embodiment of the utility model, the back pressure valve further comprises a valve cover 810 and a mounting nut 820, and the threaded section at the top of the magnetic conduction head 611 is matched with the mounting nut 820 to fixedly sleeve the valve cover 810 on the outer side of the coil 520, so that the structures such as the coil 520 can be effectively protected, the accuracy of the generated magnetic field intensity of the electromagnet structure is ensured, and the accuracy of the back pressure value adjustment of the back pressure valve is further ensured.

Through experimental tests, the response time of the back pressure valve provided by the utility model can be shortened to be within 2s, the control stability of the back pressure valve is good, the pressure repetition precision can be maintained within 1% of a set value during use, and the use efficiency and the pressure control precision of the back pressure valve can be obviously improved.

It is to be understood that the above embodiments are merely illustrative of the application of the principles of the present utility model, but not in limitation thereof. Various modifications and improvements may be made by those skilled in the art without departing from the spirit and substance of the utility model, and are also considered to be within the scope of the utility model.

Claims (10)

1. A back pressure valve is characterized by comprising a valve seat assembly, a valve core assembly and a valve body assembly, wherein,

an inflow passage, an outflow passage and a flow control groove communicated with the inflow passage and the outflow passage are formed in the valve seat assembly, and a valve port is formed at the joint of the outflow passage and the flow control groove;

the valve body assembly is arranged in the flow control groove and is in sealing connection with the valve seat assembly, and a coil is sleeved outside the valve body assembly;

the valve core assembly is arranged in the valve body assembly, the valve core assembly comprises a valve core, a first elastic piece, a second elastic piece and an armature, the valve core is connected with the armature through the first elastic piece, the valve core can close the valve port under the action of elastic force of the first elastic piece, the armature is movably arranged in the valve body assembly through the second elastic piece, the coil is used for driving the armature to overcome the elastic force of the second elastic piece and move away from the direction of the valve port through a magnetic field, so that the deformation amount of the first elastic piece when the valve core closes the valve port is changed, and the rigidity of the second elastic piece is larger than that of the first elastic piece.

2. The back pressure valve of claim 1, wherein the valve body assembly comprises a valve body and a magnetic seat, the magnetic seat is fixedly arranged in the flow control groove and is in sealing connection with the valve seat assembly, a containing blind hole is formed in the bottom of the valve body, a first containing groove is formed in the bottom of the magnetic seat, an avoidance through hole coaxial with the first containing groove is formed in the bottom of the first containing groove, the first elastic piece, the second elastic piece and the valve core are all arranged in the first containing groove, and the top end of the armature penetrates through the avoidance through hole and the armature can move along the direction of entering and exiting the containing blind hole.

3. The back pressure valve according to claim 2, further comprising a locking ring, wherein the second elastic member is a spring, the center of the spring is fixedly connected with the bottom end of the armature, and the locking ring is fixedly arranged in the first accommodating groove and compresses the edge of the spring at the bottom of the first accommodating groove.

4. The back pressure valve of claim 3 wherein the second elastic member has a fixing hole formed in the center thereof, the back pressure valve further comprising a support, the support having a threaded mounting post on the top thereof, the armature having a threaded hole formed in the bottom thereof, the threaded mounting post passing through the fixing hole of the second elastic member and being screwed into the threaded hole to fixedly connect the center of the reed with the bottom end of the armature, the first elastic member being disposed between the support and the valve core.

5. The back pressure valve of claim 4 further comprising a cartridge, wherein the bottom of the cartridge is fixedly connected to the top of the valve core, the valve core is made of an elastic material, and the first elastic member is disposed between the pad and the cartridge.

6. The back pressure valve of claim 5, wherein the first elastic member is a spring, a first annular fixing groove is formed at the bottom of the pad support, a second annular fixing groove is formed at the top of the clamping seat, the top end of the first elastic member is arranged in the first annular fixing groove, and the bottom end of the first elastic member is arranged in the second annular fixing groove.

7. The back pressure valve according to any one of claims 2 to 6, wherein the valve body comprises a magnetic guiding head and a guiding cylinder, the guiding cylinder is connected between the magnetic guiding head and the magnetic seat, a avoidance blind hole is formed at the bottom of the magnetic guiding head, and the avoidance blind hole is communicated with an inner hole of the guiding cylinder to form the accommodating blind hole.

8. The back pressure valve of claim 7 further comprising a pressure block having a receiving through hole penetrating the pressure block in a vertical direction, a second annular flange formed on an inner wall of the receiving through hole around an axis of the receiving through hole, and an annular mounting groove formed on a top of the magnet holder coaxially with the first receiving groove and connected to an outer side wall of the magnet holder; the magnetic seat is accommodated in the accommodating through hole, the second annular flange of the pressing block is accommodated in the annular mounting groove, and the bottom of the pressing block is fixedly connected with the top of the valve seat assembly so as to fixedly connect the magnetic seat with the valve seat assembly.

9. The back pressure valve of claim 8 further comprising a valve housing and a mounting nut, said valve housing being sleeved outside said coil and said pressure block, said valve housing having a mounting through hole in its top portion, said magnetic head having a threaded section in its top portion, said threaded section having an external thread formed on its outer wall, said threaded section extending from said mounting through hole to above said valve housing and being in threaded mating connection with said mounting nut.

10. The back pressure valve according to any one of claims 2 to 6, wherein the valve seat assembly includes a valve seat body in which the inflow passage, the outflow passage, and the flow control groove are formed, and an adapter in which a valve port installation groove is formed at a bottom of the flow control groove corresponding to a connection position of the outflow passage and the flow control groove, and an overflow hole through which the flow control groove communicates with the outflow passage is formed in the adapter, the overflow hole being formed as the valve port corresponding to an opening on a side of the flow control groove.