CN115183035A

CN115183035A - Back pressure valve

Info

Publication number: CN115183035A
Application number: CN202210876792.3A
Authority: CN
Inventors: 吴清; 孙鑫; 张煜彦
Original assignee: Nanjing Nuoling Biotechnology Co ltd
Current assignee: Nanjing Nuoling Biotechnology Co ltd
Priority date: 2022-07-25
Filing date: 2022-07-25
Publication date: 2022-10-14

Abstract

The invention belongs to the technical field of valves and discloses a back pressure valve. The back pressure valve comprises a valve seat, a valve cover, a valve core assembly and an adjusting assembly; the side wall of the valve seat is respectively provided with an inlet channel and an outlet channel which are communicated with the inner wall and the outer wall; the valve cover is matched with the valve seat and forms a cavity with the valve seat; the valve core assembly is arranged in the valve seat and divides the cavity into a first accommodating cavity and a second accommodating cavity, and the valve core assembly can block a first port of the outlet channel, which is far away from the outer wall of the valve seat; the adjusting assembly is positioned in the second accommodating cavity and comprises an elastic part and a first limiting part which are coaxially arranged, the first limiting part is arranged between the side wall surfaces in the valve cover in a matching manner, and the side wall surfaces in the valve cover limit the trend of non-axial movement of the first limiting part; the first limiting part comprises a first limiting structure, one end of the elastic part is connected with the valve core assembly, and the other end of the elastic part is fixedly connected with the first limiting structure. The back pressure valve has the advantages of simple structure, convenience in maintenance, low manufacturing cost, high adjusting precision and high reliability.

Description

Back pressure valve

Technical Field

The invention relates to the technical field of valves, in particular to a back pressure valve.

Background

The back pressure valve is a valve element for regulating pressure in a pipeline, and can maintain the pressure required by the pipeline under the condition of unstable pressure of the pipeline or an equipment container, so that the pump can normally output flow.

The back pressure valve works by the elastic force of a spring, and when the system pressure is lower than the set pressure, the diaphragm blocks the pipeline under the action of the elastic force of the spring: when the system pressure is higher than the set pressure, the diaphragm compresses the spring to connect the pipeline, and the liquid passes through the backpressure valve.

The existing back pressure valve has the problem of poor pressure regulation precision, and cannot be used in some systems with high requirements on pressure setting precision.

Disclosure of Invention

The invention aims to provide a back pressure valve which is simple in structure, convenient to maintain, low in manufacturing cost, high in adjusting precision and high in reliability.

In order to achieve the purpose, the invention adopts the following technical scheme:

the back pressure valve comprises a valve seat, a valve cover, a valve core assembly and an adjusting assembly; the side wall of the valve seat is respectively provided with an inlet channel and an outlet channel which are communicated with the inner wall and the outer wall; the valve cover is matched with the valve seat and forms a cavity with the valve seat; the valve core assembly is arranged in the valve seat and divides the cavity into a first accommodating cavity and a second accommodating cavity, and the valve core assembly can block a first port of the outlet channel, which is far away from the outer wall of the valve seat; the adjusting assembly is positioned in the second accommodating cavity and comprises an elastic part and a first limiting part which are coaxially arranged, the first limiting part is arranged between the side wall surfaces in the valve cover in a matching manner, and the side wall surfaces in the valve cover limit the trend of non-axial movement of the first limiting part; the first limiting part comprises a first limiting structure, one end of the elastic part is connected with the valve core assembly, and the other end of the elastic part is fixedly connected with the first limiting structure.

Optionally, the first limiting structure is a first limiting boss and/or a first limiting groove, and the side wall surface of the elastic member abuts against the first limiting structure.

Optionally, the adjusting assembly further includes a second limiting member coaxial with the elastic member, a lower wall surface of the second limiting member is fixedly connected to the valve core assembly, the second limiting member includes a second limiting structure, and the second limiting structure is fixedly connected to the elastic member.

Optionally, the second limiting structure comprises a second limiting boss, and the second limiting boss is inserted into the elastic element.

Optionally, the second limiting structure includes a limiting sidewall surrounding an outer edge of the second limiting member, and an inner sidewall of the limiting sidewall abuts against an outer side of the elastic member.

Optionally, the valve core assembly further comprises an adjusting piece, a mounting hole is formed in the upper portion of the valve cover, the adjusting piece is inserted into the mounting hole, and the lower end of the adjusting piece abuts against the first limiting piece and can push the first limiting piece to slide, so that the first limiting piece is close to or away from the valve core assembly.

Optionally, the adjusting member is a screw, the mounting hole is a threaded hole, and the adjusting member is in threaded connection with the mounting hole.

Optionally, the valve core assembly includes an elastic diaphragm and a valve core body, the elastic diaphragm divides the cavity into a first accommodating cavity and a second accommodating cavity, the valve core body is mounted on a lower wall surface of the elastic diaphragm, and the bottom of the valve core body is used for plugging the first port.

Optionally, the bottom of the cartridge body is provided with a resilient seal.

Optionally, the lower wall surface of the elastic diaphragm is provided with a mounting boss in a protruding mode.

Optionally, a pressure relief through hole is formed in the valve cover, and the interior of the valve cover is communicated with the outside atmosphere through the pressure relief through hole.

Optionally, a fitting is mounted on each of the inlet and outlet channels.

Has the advantages that:

this back pressure valve is through using the case subassembly to separate the cavity of back pressure valve for first chamber and the second chamber of holding, and the second is held the intracavity and is provided with adjusting part, and adjusting part includes the elastic component and the first locating part of coaxial setting, and first locating part includes first limit structure, and first limit structure rigid coupling can play limiting displacement in the elastic component to this elastic component, prevents that the phenomenon of axis skew or slope from appearing when the elastic component is pressurized. The back pressure valve can ensure that the axis of the elastic part in the back pressure valve does not deviate or incline when the elastic part is pressed, so that the pressure value of the back pressure valve when the back pressure valve is opened by fluid pressure is a calibration value or a preset value all the time, the precision and the reliability of the back pressure valve are improved, and the back pressure valve further has the advantages of simple structure, convenience in maintenance and low manufacturing cost.

Drawings

FIG. 1 is an isometric view of a back pressure valve provided by an embodiment of the present invention;

FIG. 2 is an exploded view of a back pressure valve provided by an embodiment of the present invention;

FIG. 3 is a cross-sectional view of a back pressure valve provided in an embodiment of the present invention;

FIG. 4 is a schematic view of the valve core assembly of this embodiment as installed on a valve seat;

FIG. 5 is a schematic diagram comparing the state of the embodiment of the present invention with the state of the prior art elastic member when compressed.

In the figure:

10. a first accommodating chamber; 20. a second accommodating cavity; 30. a joint;

100. a valve seat; 110. an inlet channel; 120. an outlet channel; 121. a first port; 130. mounting grooves;

200. a valve cover; 210. mounting holes; 220. a pressure relief through hole; 230. an installation part;

310. an elastic diaphragm; 311. mounting a boss; 312. an annular convex rib; 320. a valve core body; 321. an elastomeric seal; 322. an annular groove;

410. an elastic member; 420. a first limit piece; 421. a guide portion; 422. a first limit boss; 423. a guide side wall; 430. a second limit piece; 431. a second limit boss; 432. a limiting side wall; 441. an adjustment member; 442. and (6) mounting the nut.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

In the description of the present invention, unless otherwise explicitly specified or limited, the terms "connected", "connected" and "fixed" are to be construed broadly, e.g., as being fixedly connected, detachably connected, or integrated; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. Specific meanings of the above terms in the present invention can be understood as appropriate by those of ordinary skill in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. "beneath," "under" and "beneath" a first feature includes the first feature being directly beneath and obliquely beneath the second feature, or simply indicating that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "right", etc. are used based on the orientations or positional relationships shown in the drawings for convenience of description and simplicity of operation, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to be limiting.

Referring to fig. 1, the back pressure valve includes a valve seat 100 and a bonnet 200, the bonnet 200 is detachably mounted on the valve seat 100, and in particular, the bonnet 200 is screw-coupled to the valve seat 100, and a mounting portion 230 is provided on the bonnet 200, the mounting portion 230 being two cutting grooves oppositely provided on a side wall surface of the bonnet 200, and a mounting tool (e.g., wrench, pliers, etc.) can be engaged with the cutting grooves and grip the bonnet 200, thereby tightening and fixing the bonnet 200 on the valve seat 100.

Specifically, as shown in fig. 2 and 3, the back pressure valve in the present embodiment includes a valve seat 100, a valve cover 200, a spool assembly, and an adjustment assembly; the side wall of the valve seat 100 is provided with an inlet passage 110 and an outlet passage 120 which are opposite to each other; the bottom of the valve cover 200 is arranged on the top of the valve seat 100 and forms a cavity with the valve seat 100; the valve core assembly is arranged in the valve seat 100 and divides the cavity into a first accommodating cavity 10 and a second accommodating cavity 20, and the valve core assembly can block a first port 121 of the outlet channel 120, which is far away from the outer wall of the valve seat 100;

the adjusting assembly is located in the second accommodating cavity 20, the adjusting assembly includes an elastic member 410 and a first limiting member 420 which are coaxially arranged, the first limiting member 420 includes a guiding portion 421 and a first limiting structure which are vertically arranged, and the first limiting structure is a first limiting boss 422 and/or a first limiting groove; one end of the elastic member 410 is connected to the valve core assembly in a transmission manner, and the other end thereof abuts against the first limiting member 420. In this embodiment, the elastic element 410 is a spring, and the elastic modulus of the spring is determined by a predetermined pressure calibrated by the back pressure valve, and a person skilled in the art can determine the elastic modulus, the length and the material of the spring according to the predetermined pressure, which is not limited in this embodiment.

In this embodiment, the guiding portion 421 of the first limiting member 420 is installed between the inner side wall surfaces of the valve cap 200, and under the limitation of the inner side wall surfaces of the valve cap 200, the trend of the first limiting member 420 in non-axial movement is limited, specifically, taking the view angle shown in fig. 3 as an example, the axial movement of the first limiting member 420 is the movement along the direction of the compression spring or the release spring, and the trend of the non-axial movement mainly refers to the trend of the first limiting member 420 in movement along the horizontal direction, since the top of the spring is connected to the first limiting member 420, the movement of the first limiting member 420 along the horizontal direction may cause the spring to shift, and further the preset pressure of the spring on the valve core assembly may affect the precision of the back pressure valve, therefore, in this embodiment, the gap between the outer peripheral side wall of the first limiting member 420 and the inner side wall of the valve cap 200 is set to be less than or equal to 0.5mm, specifically, 0.1mm, 0.15mm, 0.2mm, 0.4mm, 0.5mm, and the like, and the situation that the spring shift caused by the horizontal movement is substantially avoided by the limitation of the inner side wall of the first limiting of the valve cap 420 by the inner side wall of the valve cap 200.

When the first limiting structure is the first limiting boss 422, as shown in fig. 3, the elastic element 410, i.e. the top inner ring of the spring, may be sleeved on the first limiting boss 422, so that the first limiting boss 422 limits the elastic element 410; when the first limiting structure is a limiting groove, the limiting groove may be an annular groove body formed on the lower wall surface of the first limiting member 420, the annular groove body is matched with the top ring opening of the spring in size, the top of the spring is embedded in the annular groove body to form limiting, the limiting groove may also be formed by a guide side wall 423 arranged around the outer edge of the guide portion 421, and at this time, the top of the spring is inserted between the inner wall surfaces of the guide side wall 423;

preferably, when the guide side wall 423 is disposed around the outer edge of the guide portion 421, the smaller the gap between the outer peripheral side wall surface of the guide side wall 423 and the inner side wall surface of the bonnet 200, the smaller the gap is, and the gap is selected to be smaller than 0.5mm in this embodiment, so that the guide side wall 423 is configured to prevent the first stopper 420 from shifting in the horizontal direction when the first stopper 420 is pushed, so that the first stopper 420 can stably move in the axial direction, and when the preset start pressure of the back pressure valve is adjusted, the accuracy of the adjusted back pressure valve is not reduced, and the reliability of the back pressure valve in use can be maintained after multiple adjustments.

The back pressure valve divides a cavity of the back pressure valve into a first accommodating cavity 10 and a second accommodating cavity 20 by using a valve core assembly, an adjusting assembly is arranged in the second accommodating cavity 20 and comprises an elastic part 410 and a first limiting part 420 which are coaxially arranged, the first limiting part 420 comprises a first limiting structure, the first limiting structure is fixedly connected with the elastic part 410, the elastic part 410 can be limited, and the phenomenon of axial deviation or inclination of the elastic part 410 when the elastic part is pressed is prevented; meanwhile, the first limiting member 420 is limited by the inner side wall of the bonnet 200, so that the first limiting member 420 and the second accommodating cavity 20 are more stably installed, and the first limiting member 420 is prevented from shifting when being pressed. The back pressure valve can ensure that the axis of the elastic element 410 is not deviated or inclined when the back pressure valve is pressed, so that the pressure value of the back pressure valve when the back pressure valve is opened by fluid pressure is always a calibrated preset pressure value, the precision and the reliability of the back pressure valve are improved, and the back pressure valve further has the advantages of simple structure, convenience in maintenance and low manufacturing cost.

In this embodiment, the valve cap 200 is provided with a pressure relief through hole 220, and the second accommodating cavity 20 is communicated with the external atmosphere through the pressure relief through hole 220. The volume of the second accommodating cavity 20 is reduced when the spool assembly moves under pressure, the pressure relief through hole 220 communicates the second accommodating cavity 20 with the atmosphere, so that the second accommodating cavity 20 can be prevented from generating air pressure to act on the spool assembly, specifically on the elastic diaphragm 310 of the spool assembly, the set pressure of the back pressure valve is ensured to be the force applied to the spool assembly by the deformation of the elastic piece 410, and the precision of the back pressure valve is improved.

As shown in fig. 3, the adjusting assembly further includes a second limiting member 430 coaxial with the elastic member 410, a lower wall surface of the second limiting member 430 abuts against the valve core assembly, and a second limiting structure is disposed on the second limiting member 430 and is fixedly connected to the elastic member 410. In this embodiment, the second limiting structure includes a second limiting boss 431 protruding on the second limiting member 430, the second limiting boss 431 is inserted into the elastic member 410, and more specifically, the second limiting boss 431 is in interference fit with the elastic member 410, that is, the inner ring at the bottom of the spring, so that the second limiting boss 431 of the second limiting member 430 can further fix the lower end of the elastic member 410, thereby avoiding the phenomena of possible offset, bottom offset, and self-deflection of the spring, and further improving the accuracy of the back pressure valve.

Optionally, the second limiting structure includes a limiting sidewall 432 surrounded by the outer edge of the second limiting member 430, an inner sidewall of the limiting sidewall 432 abuts against the outer side of the elastic member 410, and the limiting sidewall 432 can further fix the lower end of the elastic member 410, so that the phenomena of offset and falling of the bottom of the spring are avoided, and the accuracy of the back pressure valve is further improved; in this embodiment, a certain interval is left between the outer wall surface of the second position-limiting member 430 and the inner wall surface of the bonnet 200, the interval is 1mm to 5mm, the smaller the interval is, the better the interval is, the small interval can ensure that the bottom surface of the second position-limiting member 430 is set to be larger, the contact area between the second position-limiting member 430 and the valve core assembly can be made as large as possible, uneven deformation when the valve core assembly is stressed is prevented, the movement of the valve core assembly, the elastic diaphragm 310 and the second position-limiting member 430 is stabilized, the precision of the back pressure valve is ensured, and when the interval is too small, the second position-limiting member 430 contacts the inner wall surface of the bonnet 200 to generate friction force to influence the precision of the back pressure valve, so the interval is designed to be greater than or equal to 1mm, the interval is set to be 1mm in this embodiment, not only can be enough large for the contact area between the second position-limiting member 430 and the elastic diaphragm 310, but also can prevent the friction phenomenon between the second position-limiting member 430 and the inner wall surface of the bonnet 200 when the second position-limiting member 430 moves, and ensure that the force of fluid from the first accommodating cavity 10 received by the valve core assembly can be effectively fed back to the elastic member 410, and improve the precision of the back pressure valve.

Referring to fig. 2 and fig. 3, in the present embodiment, the valve cover 200 further includes an adjusting member 441, the upper portion of the valve cover 200 is provided with a mounting hole 210, the adjusting member 441 is inserted into the mounting hole 210, and the lower end of the adjusting member 441 abuts against the first limiting member 420 and can push the first limiting member 420 to move, so that the first limiting member 420 is close to or away from the valve core assembly. In this embodiment, the adjusting member 441 is a screw, the mounting hole 210 is a threaded hole, and the adjusting member 441 is in threaded connection with the mounting hole 210. Alternatively, the adjusting member 441 is a screw, and a mounting nut 442 may be further disposed above the mounting hole 210, and the screw is threadedly coupled to the mounting nut 442. Through twisting this screw, can make this screw along mounting hole 210 up-and-down motion, make guide portion 421 up-and-down motion, thereby adjust the predetermined decrement of elastic component 410, change the preset starting pressure of this back pressure valve, make this back pressure valve can satisfy the pressure regulating demand of user at the difference, adjust to suitable position back at regulating part 411, twist nut 442 to nut 422 and mounting hole 210 butt, help further fixing the regulating part 411 position this moment, and then avoid the preset starting pressure of back pressure valve to receive the influence because of the position change of regulating part 411.

With continued reference to FIG. 3, the inlet passage 110 and the outlet passage 120 are each provided with a fitting 30. The joint 30 can conveniently install the back pressure valve in the air path of a desired regulated pressure.

Optionally, the valve core assembly includes an elastic diaphragm 310 and a valve core body 320, the elastic diaphragm 310 is installed inside the valve seat 100, the valve core body 320 is installed on a lower wall surface of the elastic diaphragm 310, an elastic sealing member 321 is disposed at a bottom of the valve core body 320, and the elastic sealing member 321 can abut against the first port 121. In this embodiment, the elastic diaphragm 310 divides the cavity formed after the valve cover 200 is installed in the valve seat 100, into the first accommodating chamber 10 and the second accommodating chamber 20, and preferably, the outer edge of the elastic diaphragm 310 is in an interference fit with the inner side wall of the valve seat 100 in this embodiment, thereby ensuring the sealing property.

As shown in fig. 4, in order to further ensure the sealing property of the elastic diaphragm 310 separating the first accommodating chamber 10 and the second accommodating chamber 20, an annular rib 312 is convexly provided on the lower wall surface of the elastic diaphragm 310, and the annular rib 312 is provided at the middle part of the lower wall surface of the elastic diaphragm 310, and is intended to abut against the upper wall surface of the valve body 320 to increase the sealing property. Further, an annular groove 322 may be formed on the upper wall surface of the valve body 320 to be fitted with the annular rib 312. Further, the annular ribs 312 are connected with the annular grooves 322 in an interference fit manner, and the annular ribs 312 and the annular grooves 322 are provided with a plurality of ribs in a one-to-one correspondence manner, i.e., 3 ribs are provided in this embodiment.

In the embodiment, an annular mounting boss 311 is convexly arranged at the edge of the lower wall surface of the elastic diaphragm 310, when the valve cap 200 is mounted in the valve seat 100 in a matching manner, for example, the valve cap 200 may contact the outer edge of the elastic diaphragm 310, during the screwing process, the valve cap 200 presses the upper wall surface of the elastic diaphragm 310, when the valve cap 200 is mounted in the valve seat 100 in a matching manner, the valve cap 200 may press the outer edge of the elastic diaphragm 310, at this time, a slight wrinkle or deformation may occur on the upper and lower wall surfaces of the elastic diaphragm 310 due to a friction force, so that a gap may occur between the outer edge of the elastic diaphragm 310 and the inner side wall of the valve seat 100, which affects the sealing performance, and the mounting boss 311 is arranged in this embodiment, on one hand, the outer edge structure of the elastic diaphragm 310 is strengthened, and on the other hand, an influence on the sealing performance due to the gap occurring in such a situation can be avoided;

furthermore, in the embodiment, the mounting groove 130 is recessed and formed at the position where the upper surface of the step-shaped protrusion on the inner wall surface of the valve seat 100 corresponds to the mounting boss 311, and the shape of the mounting groove 130 is supposed to correspond to the shape of the mounting boss 311, so that in the screwing mounting process of the valve cover 200 and the valve seat 100, the bottom surface of the valve cover 200 can extrude the outer edge of the elastic diaphragm 310, and the mounting boss 311 is pressed into the mounting groove 130 on the valve seat 100, thereby, under the guiding and limiting of the mounting groove 130, the deformation tendency of the elastic diaphragm 310 can be reduced, and the sealing effect can be improved; further, the mounting boss 311 may be in interference fit with the mounting groove 130 to enhance the sealing effect.

Elastic sealing element 321 can guarantee that valve core body 320 is better to the sealed effect of first port 121, elastic sealing element 321 is the rubber piece in this embodiment, also can be the elastic construction of other materials, in this embodiment, the position department that corresponds first port 121 at valve core body 320 lower wall face is equipped with the installation position, the upper portion of elastic sealing element 321 is inlayed and is located in the installation position, the lower wall face of elastic sealing element 321 is under elastic component 410's effect, the butt is in first port 121 department, the leakproofness is better, the phenomenon of weeping prevents to appear.

Specifically, the elastic diaphragm 310 is provided with a through hole, more specifically, the through hole is disposed in the middle of the elastic diaphragm 310, the second limiting member 430 is provided with a threaded hole coaxial with the through hole, the valve core body 320 includes a threaded portion, the threaded portion is installed in cooperation with the threaded hole, so that the valve core body 320 and the second limiting member 430 clamp the elastic diaphragm 310 therebetween, the valve core body 320 and the second limiting member 430 are fixedly connected to the elastic diaphragm 310, and the annular rib 322 disposed in the middle of the lower wall surface of the elastic diaphragm 310 cooperates with the upper wall surface of the valve core body 320, and cooperates with the fastening connection of the threaded portion, thereby ensuring the sealing performance of the middle position of the elastic diaphragm 310.

The pressure regulating operation of the back pressure valve in this embodiment is described in detail below:

after the fluid flows into the first accommodating chamber 10 from the inlet channel 110, pressure can be generated on the elastic diaphragm 310, and when the pressure reaches a preset value (that is, the pressure of the fluid in the first accommodating chamber 10 on the elastic diaphragm 310 is the same as the acting force of the elastic member 410 on the elastic diaphragm 310), the fluid pressure continues to increase, so that the elastic diaphragm 310 and the valve core body 320 move upwards and can compress the spring, and thus the first port 121 is opened, the fluid can flow out from the outlet channel 120, and the functions of pressure relief or pipeline opening and closing are realized; when the fluid pressure drops below the preset value, the spring pushes the diaphragm and the valve core body 320 to drop, and the first port 121 is sealed off again.

Specifically, as shown in fig. 5, the right side of the figure shows a prior art back pressure valve, two ends of a spring of the prior art are not fixed and limited, and a structural member in the back pressure valve is acted by a constantly changing fluid pressure, so that the spring can have phenomena of deflection, inclination and the like, the actual pressure of the spring on an elastic diaphragm 310 deviates from a preset pressure, the precision of the back pressure valve is reduced, and the long-term use can further increase the degree of deflection of the spring, and further reduce the precision of the back pressure valve. In the spring shown in the left side of the figure in the present embodiment, because the two ends of the spring are respectively subjected to the fixed limiting action of the first limiting boss 422 and the second limiting boss 431 in the first limiting member 420 and the second limiting member 430 when the spring is compressed, the spring does not deviate or incline, so that the back pressure valve in the present embodiment can ensure that the axis of the internal elastic member 410 does not deviate or incline when the spring is compressed, so that the pressure value of the back pressure valve when the back pressure valve is opened by fluid pressure is always a preset value, and the precision and the reliability of the back pressure valve are improved.

Through the test, compare in current back pressure valve, back pressure valve in this embodiment can improve precision and reliability from following several aspects:

1. flow sensitivity: the flow can cause the set backpressure value to fluctuate, the fluctuation of the existing backpressure valve exceeds 10 percent, and the fluctuation of the backpressure valve in the embodiment can be controlled within 3 percent under the flow of 0-5L/min;

2. difference between the opening pressure value and the set back pressure value: the difference value of the existing back pressure valve exceeds 20 percent, and the control in the embodiment can be controlled within 10 percent;

3. stability of the regulation: when the adjusting member 441 is adjusted, the existing backpressure valve fluctuates due to the shaking of the internal structure, but the backpressure valve in this embodiment does not fluctuate;

4. long-term stability: after 100 ten thousand opening/closing tests, the backpressure value of the existing backpressure valve is reduced by about 30%, the backpressure value of the backpressure valve in the embodiment is still within 5%, and after 3000 ten thousand opening/closing tests, the backpressure value of the backpressure valve in the embodiment can still meet the precision within 5%; in addition, in order to meet the long-term reliability requirement of 5% precision, the back pressure valve in the prior art generally uses precise electronic components for matching, such as: the combination of the pressure sensor, the electromagnetic valve, the proportional valve, the control circuit and the like has higher cost, but the back pressure valve in the embodiment does not need to use an electronic device, can meet the requirement of long-term reliability of precision only by the internal structural design, and effectively controls the production cost.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Numerous obvious variations, adaptations and substitutions will occur to those skilled in the art without departing from the scope of the invention. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A back pressure valve comprising:

the valve seat (100), wherein an inlet channel (110) and an outlet channel (120) which are communicated with the inner wall and the outer wall are respectively arranged on the valve seat (100);

the valve cover (200), the said valve cover (200) cooperates with said valve base (100) to mount, and form a cavity with said valve base (100);

the valve core assembly is arranged in the valve seat (100) and divides the cavity into a first accommodating cavity (10) and a second accommodating cavity (20), and the valve core assembly can block a first port (121) of the outlet channel (120) at the first accommodating cavity (10);

it is characterized by also comprising:

the adjusting assembly is positioned in the second accommodating cavity (20), the adjusting assembly comprises an elastic part (410) and a first limiting part (420) which are coaxially arranged, the first limiting part (420) is arranged between inner side wall surfaces of the valve cover (200) in a matching manner, and the inner side wall surfaces of the valve cover (200) limit the tendency of non-axial movement of the first limiting part (420); the first limiting part (420) comprises a first limiting structure, one end of the elastic part (410) is connected with the valve core assembly, and the other end of the elastic part is fixedly connected with the first limiting structure.

2. The back pressure valve of claim 1, wherein the first limit structure is a first limit boss (422) and/or a first limit groove, and a side wall surface of the elastic member (410) abuts against the first limit structure.

3. The back pressure valve according to claim 1, wherein the adjusting assembly further comprises a second limiting member (430) coaxial with the elastic member (410), a lower wall surface of the second limiting member (430) is fixedly connected to the valve core assembly, and the second limiting member (430) comprises a second limiting structure fixedly connected to the elastic member (410).

4. The back pressure valve of claim 3, wherein the second limit structure comprises a second limit boss (431), and the second limit boss (431) is inserted into the elastic member (410).

5. The back pressure valve according to claim 3, wherein the second limiting structure comprises a limiting sidewall (432) surrounding at an outer edge of the second limiting member (430), an inner sidewall surface of the limiting sidewall (432) abuts against an outer side of the elastic member (410).

6. The back pressure valve according to claim 1, further comprising an adjusting member (441), wherein a mounting hole (210) is formed in the upper portion of the bonnet (200), the adjusting member (441) is inserted into the mounting hole (210), and the lower end of the adjusting member (441) abuts against the first limiting member (420) and can push the first limiting member (420) to slide, so that the first limiting member (420) is close to or away from the spool assembly.

7. Back pressure valve according to claim 6, characterized in that the adjustment member (441) is a screw, the mounting hole (210) is a threaded hole, the adjustment member (441) being screwed with the mounting hole (210).

8. The backpressure valve according to any of claims 1 to 7, characterized in that the spool assembly comprises an elastic diaphragm (310) and a spool body (320), the elastic diaphragm (310) divides the cavity into a first accommodating chamber (10) and a second accommodating chamber (20), the spool body (320) is installed on the lower wall surface of the elastic diaphragm (310), and the bottom of the spool body (320) is used for plugging the first port (121).

9. The back pressure valve of claim 8, wherein a bottom of the spool body (320) is provided with an elastic sealing member (321).

10. Back pressure valve according to claim 8, characterized in that the lower wall of the elastic diaphragm (310) is provided with a mounting boss (311) in relief.

11. A back pressure valve according to any one of claims 1-7, wherein the valve cover (200) is provided with a pressure relief through hole (220), and the inside of the valve cover (200) is communicated with the outside atmosphere through the pressure relief through hole (220).