A back pressure valve

Abstract

The application 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. An inlet channel and an outlet channel are respectively arranged on the side wall of the valve seat. The valve cover is installed in cooperation with the valve seat and forms a cavity with the valve seat. The valve core assembly is installed in the valve seat and divides the cavity into a first accommodating cavity and a second accommodating cavity. The valve core assembly can block the first port of the outlet channel away from the outer wall of the valve seat. The adjusting assembly is located in the second accommodating cavity. The adjusting assembly comprises a coaxial elastic member and a first limiting member. The first limiting member is arranged between the inner side wall surface of the valve cover. The inner side wall surface of the valve cover limits the non-axial movement of the first limiting member. The first limiting member comprises a first limiting structure. One end of the elastic member is connected with the valve core assembly, and the other end is fixedly connected with the first limiting structure. The back pressure valve has the advantages of simple structure, convenient maintenance, low manufacturing cost, high adjusting precision and high reliability.

Description

Technical Field

[0001] This invention relates to the field of valve technology, and more particularly to a back pressure valve. Background Technology

[0002] A back pressure valve is a valve element used to regulate pressure in pipelines. When the pressure in a pipeline or equipment container is unstable, the back pressure valve can maintain the required pressure in the pipeline, allowing the pump to output flow normally.

[0003] The back pressure valve works by the elastic force of a spring. When the system pressure is lower than the set pressure, the diaphragm blocks the pipeline under the action of the spring. When the system pressure is higher than the set pressure, the diaphragm compresses the spring, opening the pipeline and allowing liquid to pass through the back pressure valve.

[0004] Existing back pressure valves have the problem of poor pressure regulation accuracy, and cannot be used in some systems that require high pressure setting accuracy. Summary of the Invention

[0005] The purpose of this invention is to provide a back pressure valve that has a simple structure, is easy to maintain, has low manufacturing cost, and has the advantages of high adjustment accuracy and high reliability.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] The back pressure valve includes a valve seat, a valve cover, a valve core assembly, and an adjusting assembly. The valve seat sidewall has an inlet channel and an outlet channel connecting the inner and outer walls. The valve cover is fitted to the valve seat, forming a cavity. The valve core assembly is installed inside the valve seat, dividing the cavity into a first receiving cavity and a second receiving cavity. The valve core assembly can block the first port of the outlet channel away from the outer wall of the valve seat. The adjusting assembly is located in the second receiving cavity and includes a coaxially arranged elastic element and a first limiting element. The first limiting element is fitted between the inner sidewalls of the valve cover, and the inner sidewalls of the valve cover restrict the non-axial movement of the first limiting element. The first limiting element includes a first limiting structure; one end of the elastic element is connected to the valve core assembly, and the other end is fixedly connected to the first limiting structure.

[0008] Optionally, the first limiting structure is a first limiting boss and / or a first limiting groove, and the side wall of the elastic member abuts against the first limiting structure.

[0009] Optionally, the adjusting assembly further includes a second limiting member coaxial with the elastic member. The lower wall of the second limiting member is fixedly connected to the valve core assembly. The second limiting member includes a second limiting structure, which is fixedly connected to the elastic member.

[0010] Optionally, the second limiting structure includes a second limiting boss, which is inserted into the elastic member.

[0011] Optionally, the second limiting structure includes a limiting sidewall surrounding the outer edge of the second limiting member, with the inner sidewall surface of the limiting sidewall abutting against the outer side of the elastic member.

[0012] Optionally, it also includes an adjusting member, with a mounting hole on the upper part of the valve cover, the adjusting member being inserted into the mounting hole, the lower end of the adjusting member abutting against the first limiting member, and being able to push the first limiting member to slide so that the first limiting member moves closer to or away from the valve core assembly.

[0013] Optionally, the adjusting element is a screw, the mounting hole is a threaded hole, and the adjusting element is threadedly connected to the mounting hole.

[0014] Optionally, the valve core assembly includes an elastic diaphragm and a valve core body. The elastic diaphragm divides the cavity into a first receiving cavity and a second receiving cavity. The valve core body is mounted on the lower wall of the elastic diaphragm, and the bottom of the valve core body is used to seal the first port.

[0015] Optionally, a resilient seal is provided at the bottom of the valve core body.

[0016] Optionally, the lower wall of the elastic diaphragm is provided with a mounting boss.

[0017] Optionally, a pressure relief hole is provided on the valve cover, through which the interior of the valve cover is connected to the external atmosphere.

[0018] Optionally, connectors are installed on both the inlet and outlet channels.

[0019] Beneficial effects:

[0020] This back pressure valve uses a valve core assembly to divide its cavity into a first receiving cavity and a second receiving cavity. An adjusting assembly is installed in the second receiving cavity. This adjusting assembly includes a coaxially arranged elastic element and a first limiting element. The first limiting element includes a first limiting structure, which is fixed to the elastic element and limits its movement, preventing axial displacement or tilting of the elastic element under pressure. This back pressure valve ensures that the internal elastic element does not shift or tilt under pressure, ensuring that the pressure value when the back pressure valve opens under fluid pressure is always the calibrated or preset value. This improves the accuracy and reliability of the back pressure valve and also has the advantages of simple structure, convenient maintenance, and low manufacturing cost. Attached Figure Description

[0021] Figure 1 This is an isometric view of the back pressure valve provided in a specific embodiment of the present invention;

[0022] Figure 2 This is an exploded view of the back pressure valve provided in a specific embodiment of the present invention;

[0023] Figure 3 This is a cross-sectional view of the back pressure valve provided in a specific embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the valve core assembly installed on the valve seat in this embodiment;

[0025] Figure 5 This is a schematic diagram comparing the specific embodiments of the present invention with the state of the elastic element under pressure in the prior art.

[0026] In the picture:

[0027] 10. First receiving cavity; 20. Second receiving cavity; 30. Connector;

[0028] 100, Valve seat; 110, Inlet channel; 120, Outlet channel; 121, First port; 130, Mounting slot;

[0029] 200, Valve cover; 210, Mounting hole; 220, Pressure relief hole; 230, Mounting part;

[0030] 310. Elastic diaphragm; 311. Mounting boss; 312. Annular rib; 320. Valve core body; 321. Elastic seal; 322. Annular groove;

[0031] 410. Elastic element; 420. First limiting element; 421. Guide part; 422. First limiting boss; 423. Guide sidewall; 430. Second limiting element; 431. Second limiting boss; 432. Limiting sidewall; 441. Adjusting element; 442. Mounting nut. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0033] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0036] Please refer to Figure 1 The back pressure valve includes a valve seat 100 and a valve cover 200. The valve cover 200 is detachably mounted on the valve seat 100. Specifically, the valve cover 200 is threadedly connected to the valve seat 100, and the valve cover 200 is provided with a mounting part 230. The mounting part 230 consists of two grooves that are oppositely provided on the side wall of the valve cover 200. Installation tools (such as wrenches, pliers, etc.) can cooperate with the grooves and clamp the valve cover 200, thereby tightening and fixing the valve cover 200 to the valve seat 100.

[0037] Specifically, such as Figure 2 and Figure 3 As shown, in this embodiment, the back pressure valve includes a valve seat 100, a valve cover 200, a valve core assembly, and an adjustment assembly; an inlet channel 110 and an outlet channel 120 are provided opposite to each other on the side wall of the valve seat 100; the bottom of the valve cover 200 is installed on the top of the valve seat 100 and forms a cavity with the valve seat 100; the valve core assembly is installed inside the valve seat 100 and divides the cavity into a first receiving cavity 10 and a second receiving cavity 20; the valve core assembly can block the first port 121 of the outlet channel 120 that is away from the outer wall of the valve seat 100.

[0038] The adjusting assembly is located in the second receiving cavity 20. The adjusting assembly includes an elastic element 410 and a first limiting element 420 coaxially arranged. The first limiting element 420 includes a guide portion 421 arranged vertically and a first limiting structure, which is a first limiting boss 422 and / or a first limiting groove. One end of the elastic element 410 is connected to the valve core assembly, and the other end abuts against the first limiting element 420. In this embodiment, the elastic element 410 is selected as a spring. The elastic modulus of the spring is determined by the preset pressure marked by the back pressure valve. Those skilled in the art can determine the elastic modulus, length, and material of the spring based on the preset pressure. This embodiment does not impose specific limitations.

[0039] In this embodiment, the guide portion 421 of the first limiting member 420 is installed between the inner sidewalls of the valve cover 200. Under the limiting effect of the inner sidewalls of the valve cover 200, the tendency of the first limiting member 420 to move non-axially is restricted. Specifically, with... Figure 3 Taking the perspective shown 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. The non-axial movement trend mainly refers to the trend of the first limiting member 420 moving in the horizontal direction. Since the top of the spring is connected to the first limiting member 420, the horizontal movement of the first limiting member 420 will cause the spring to deviate, thereby affecting the preset pressure of the spring on the valve core assembly and affecting the accuracy 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 cover 200 is set to ≤0.5mm, specifically 0mm, 0.1mm, 0.15mm, 0.2mm, 0.4mm, 0.5mm, etc. In this way, the limiting formed by the inner side wall of the valve cover 200 on the first limiting member 420 can basically avoid the above-mentioned horizontal movement causing the spring to deviate.

[0040] When the first limiting structure is the first limiting boss 422, such as Figure 3 As shown, the elastic element 410, i.e., the top inner ring of the spring, can be sleeved on the first limiting boss 422, thereby limiting the elastic element 410 by the first limiting boss 422; when the first limiting structure is a limiting groove, the limiting groove can be an annular groove opened on the lower wall of the first limiting element 420, the annular groove is matched with the size of the top ring of the spring, and the top of the spring is embedded in the annular groove to form a limit; the limiting groove can also be formed by the guide sidewall 423 surrounding the outer edge of the guide part 421, in which case the top of the spring is inserted between the inner wall surfaces of the guide sidewall 423;

[0041] Preferably, when a guide sidewall 423 is provided around the outer edge of the guide portion 421, the gap between the outer peripheral sidewall of the guide sidewall 423 and the inner sidewall of the valve cover 200 should be as small as possible. In this embodiment, it is selected to be less than 0.5mm. The guide sidewall 423 configured in this way can prevent the first limiting member 420 from shifting in the horizontal direction when it is pushed, and can move stably along the axial direction. When adjusting the preset starting pressure of the back pressure valve, its accuracy after adjustment will not decrease, and its reliability during use can still be maintained after multiple adjustments.

[0042] This back pressure valve uses a valve core assembly to divide its cavity into a first receiving cavity 10 and a second receiving cavity 20. An adjustment assembly is installed within the second receiving cavity 20. This assembly includes a coaxially arranged elastic element 410 and a first limiting element 420. The first limiting element 420 includes a first limiting structure, which is fixedly connected to the elastic element 410, limiting its position and preventing axial displacement or tilting under pressure. Simultaneously, the first limiting element 420 is further stabilized within the valve cover 200 by the inner wall of the valve cover 200, preventing displacement under pressure. This back pressure valve ensures that the internal elastic element 410 does not shift or tilt under pressure, guaranteeing that the pressure value when the back pressure valve opens under fluid pressure is always the calibrated preset pressure value. This improves the accuracy and reliability of the back pressure valve and also offers advantages such as simple structure, convenient maintenance, and low manufacturing cost.

[0043] In this embodiment, a pressure relief through-hole 220 is provided on the valve cover 200, and the second receiving cavity 20 is connected to the external atmosphere through the pressure relief through-hole 220. This is because when the valve core assembly is pressed and moves, the volume of the second receiving cavity 20 will decrease. The pressure relief through-hole 220 connects the second receiving cavity 20 to the atmosphere, which can prevent the air pressure generated in the second receiving cavity 20 from acting on the valve core assembly, specifically on the elastic diaphragm 310 of the valve core assembly. This ensures that the set pressure of the back pressure valve is the force applied to the valve core assembly by the deformation of the elastic element 410, thereby improving the accuracy of the back pressure valve.

[0044] like Figure 3As shown, the adjusting assembly also includes a second limiting member 430 coaxial with the elastic member 410. The lower wall surface of the second limiting member 430 abuts against the valve core assembly. A second limiting structure is provided on the second limiting member 430, and the second limiting structure is fixed to the elastic member 410. In this embodiment, the second limiting structure includes a second limiting boss 431 protruding from the second limiting member 430. The second limiting boss 431 is inserted into the elastic member 410. More specifically, the second limiting boss 431 is interference-fitted with the elastic member 410, i.e., the inner ring of the bottom of the spring. Thus, the second limiting boss 431 of the second limiting member 430 can further fix the lower end of the elastic member 410, avoiding possible spring offset, bottom offset, and self-deflection, thereby further improving the accuracy of the back pressure valve.

[0045] Optionally, the second limiting structure includes a limiting sidewall 432 surrounding the outer edge of the second limiting member 430. The inner sidewall of the limiting sidewall 432 abuts against the outer side of the elastic member 410. This limiting sidewall 432 can further fix the lower end of the elastic member 410, preventing possible displacement or detachment of the bottom of the spring, and further improving the accuracy of the back pressure valve. In this embodiment, there is a certain gap between the outer wall surface of the second limiting member 430 and the inner wall surface of the valve cover 200. This gap is 1mm to 5mm. The smaller the gap, the better, because a small gap can ensure that the bottom surface of the second limiting member 430 is set to be larger, so that the contact area between the second limiting member 430 and the valve core assembly is as large as possible, preventing the valve core from being... When the components are subjected to force, uneven deformation occurs, which stabilizes the movement of the valve core assembly, the elastic diaphragm 310, and the second limiting member 430, ensuring the accuracy of the back pressure valve. However, if the interval is too small, it will cause friction between the second limiting member 430 and the inner wall of the valve cover 200 when the second limiting member 430 moves, affecting the accuracy of the back pressure valve. Therefore, the interval is designed to be ≥1mm. In this embodiment, the interval is set to 1mm, which not only allows the second limiting member 430 and the elastic diaphragm 310 to have a sufficiently large contact area, but also prevents friction between the second limiting member 430 and the inner wall of the valve cover 200 when the second limiting member 430 moves. This ensures that the force from the fluid in the first receiving cavity 10 on the valve core assembly can be effectively fed back to the elastic member 410, thereby improving the accuracy of the back pressure valve.

[0046] Please continue to refer to this. Figure 2 and Figure 3In this embodiment, an adjusting member 441 is also included. A mounting hole 210 is provided on the upper part of the valve cover 200. The adjusting member 441 is inserted into the mounting hole 210, and its lower end abuts against the first limiting member 420, enabling it to move and move closer to or further away from the valve core assembly. In this embodiment, the adjusting member 441 is a screw, and the mounting hole 210 is a threaded hole. The adjusting member 441 is threadedly connected to the mounting hole 210. Optionally, the adjusting member 441 is a screw, and a mounting nut 442 may also be provided above the mounting hole 210, with the screw threadedly connected to the mounting nut 442. By twisting the screw, it can be moved up and down along the mounting hole 210, causing the guide part 421 to move up and down, thereby adjusting the preset compression amount of the elastic element 410 and changing the preset starting pressure of the back pressure valve. This allows the back pressure valve to meet the user's different pressure adjustment needs. After the adjusting element 411 is adjusted to the appropriate position, the nut 442 is tightened until it abuts against the mounting hole 210. This helps to further fix the position of the adjusting element 411, thereby preventing the preset starting pressure of the back pressure valve from being affected by changes in the position of the adjusting element 411.

[0047] Please continue to refer to this. Figure 3 Both the inlet channel 110 and the outlet channel 120 are equipped with connectors 30. These connectors 30 allow the back pressure valve to be easily installed in the air circuit where the required pressure is to be regulated.

[0048] 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, and the valve core body 320 is installed on the lower wall of the elastic diaphragm 310. An elastic sealing element 321 is provided at the bottom of the valve core body 320, and the elastic sealing element 321 can abut against the first port 121. In this embodiment, the elastic diaphragm 310 divides the cavity formed after the valve cover 200 and the valve seat 100 are fitted together into a first receiving cavity 10 and a second receiving cavity 20. Preferably, in this embodiment, the outer edge of the elastic diaphragm 310 is press-fitted with the inner wall of the valve seat 100, thereby ensuring sealing.

[0049] like Figure 4 As shown, to further ensure the sealing of the elastic diaphragm 310 separating the first receiving cavity 10 and the second receiving cavity 20, an annular rib 312 is provided on the lower wall surface of the elastic diaphragm 310. The annular rib 312 is located in the middle of the lower wall surface of the elastic diaphragm 310, and its purpose is to abut against the upper wall surface of the valve core body 320 to increase the sealing performance. Furthermore, an annular groove 322 that cooperates with the annular rib 312 can be provided on the upper wall surface of the valve core body 320. Furthermore, the annular rib 312 and the annular groove 322 are connected by an interference fit, and multiple annular ribs 312 and annular grooves 322 are provided in a one-to-one correspondence. In this embodiment, three are provided.

[0050] A stepped protrusion is formed on the inner wall of the valve seat 100 corresponding to the portion below the elastic diaphragm 310. After the valve cover 200 and the valve seat 100 are installed together, the outer ring of the lower wall of the elastic diaphragm 310 contacts the stepped protrusion. In this embodiment, an annular mounting boss 311 is provided at the edge of the lower wall of the elastic diaphragm 310. When the valve cover 200 and the valve seat 100 are installed together, taking the threaded connection as an example, the valve cover 200 usually contacts the outer edge of the elastic diaphragm 310. During the tightening process, the valve cover 200... When the valve cover 200 is installed, the upper wall of the elastic diaphragm 310 is squeezed. At this time, the upper and lower walls of the elastic diaphragm 310 may be slightly wrinkled or deformed due to friction. This may cause a gap between the outer edge of the elastic diaphragm 310 and the inner wall of the valve seat 100, affecting the sealing performance. The installation boss 311 in this embodiment strengthens the outer edge structure of the elastic diaphragm 310 on the one hand, and avoids the gap from affecting the sealing performance in such cases on the other hand.

[0051] Furthermore, in this embodiment, a mounting groove 130 is recessed on the upper surface of the stepped protrusion on the inner wall of the valve seat 100, corresponding to the mounting boss 311. The shape of the mounting groove 130 corresponds to the shape of the mounting boss 311. During the tightening and installation of the valve cover 200 and the valve seat 100, the bottom surface of the valve cover 200 will press the outer edge of the elastic diaphragm 310, causing the mounting boss 311 to be pressed into the mounting groove 130 on the valve seat 100. Thus, under the guidance and limitation of the mounting groove 130, the deformation tendency of the elastic diaphragm 310 can be reduced, and the sealing effect can be improved. Furthermore, the mounting boss 311 can be interference-fitted with the mounting groove 130 to enhance the sealing effect.

[0052] The elastic seal 321 can ensure a better sealing effect of the valve core body 320 to the first port 121. In this embodiment, the elastic seal 321 is a rubber block, but it can also be an elastic structure of other materials. In this embodiment, an installation position is provided on the lower wall of the valve core body 320 corresponding to the position of the first port 121. The upper part of the elastic seal 321 is embedded in the installation position. Under the action of the elastic member 410, the lower wall of the elastic seal 321 abuts against the first port 121, resulting in better sealing and preventing leakage.

[0053] Specifically, the elastic diaphragm 310 is provided with a through hole, more specifically, the through hole is provided 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 fitted with the aforementioned threaded hole, thereby causing the valve core body 320 and the second limiting member 430 to clamp the elastic diaphragm 310 between them, so that the valve core body 320 and the second limiting member 430 are fixed to the elastic diaphragm 310. The annular rib 322 provided in the middle of the lower wall of the elastic diaphragm 310, together with the upper wall of the valve core body 320 and the fastening connection of the threaded portion, can ensure the sealing of the middle position of the elastic diaphragm 310.

[0054] The pressure regulating process of the back pressure valve in this embodiment is described in detail below:

[0055] After the fluid flows into the first receiving cavity 10 through the inlet channel 110, it can exert pressure on the elastic diaphragm 310. When the pressure reaches the preset value (that is, the pressure of the fluid in the first receiving cavity 10 on the elastic diaphragm 310 is the same as the force exerted by the elastic element 410 on the elastic diaphragm 310), the fluid pressure continues to increase, which will cause the elastic diaphragm 310 and the valve core body 320 to move upward and compress the spring, thereby opening the first port 121, and the fluid can flow out from the outlet channel 120 to realize the function of pressure relief or opening and closing the pipeline; when the fluid pressure drops below the preset value, the spring pushes the diaphragm and the valve core body 320 downward, re-sealing the first port 121.

[0056] Specifically, such as Figure 5 As shown in the figure, the right side illustrates a back pressure valve in the prior art. Because the spring ends are not fixed or limited, the internal components of the back pressure valve are subjected to constantly changing fluid pressure, causing the spring to deflect, twist, or tilt. This results in a deviation between the actual pressure exerted by the spring on the elastic diaphragm 310 and the preset pressure, leading to a decrease in the accuracy of the back pressure valve. Long-term use will further increase the spring's deviation, further reducing the accuracy of the back pressure valve. In contrast, the spring in this embodiment, shown on the left side, is fixed and limited by the first limiting boss 422 and the second limiting boss 431 of the first limiting member 420 and the second limiting member 430, respectively, preventing deviation or tilting. Therefore, the back pressure valve in this embodiment ensures that the axis of its internal elastic member 410 does not shift or tilt when compressed, ensuring that the pressure value when the back pressure valve opens under fluid pressure is always the preset value, thus improving the accuracy and reliability of the back pressure valve.

[0057] After testing, compared with existing back pressure valves, the back pressure valve in this embodiment can improve accuracy and reliability in the following aspects:

[0058] 1. Flow sensitivity: The flow rate will cause fluctuations in the set back pressure value. Existing back pressure valves have fluctuations of more than 10%. In this embodiment, the back pressure valve can control the back pressure value fluctuation within 3% at a flow rate of 0-5L / min.

[0059] 2. Difference between opening pressure value and set back pressure value: The difference between existing back pressure valves exceeds 20%, while the difference in this embodiment can be controlled within 10%;

[0060] 3. Stability of adjustment: When the adjusting component 441 is adjusted, the back pressure value of the existing back pressure valve will fluctuate due to the shaking of the internal structure, while the back pressure valve in this embodiment will not fluctuate.

[0061] 4. Long-term stability: After 1 million opening / closing cycles, the back pressure value of existing back pressure valves decreased by about 30%, while the back pressure value of the back pressure valve in this embodiment remains within 5%. Furthermore, after 30 million opening / closing cycles, the back pressure value of the back pressure valve in this embodiment still meets the accuracy requirement of within 5%. Moreover, in order to meet the long-term reliability requirement of 5% accuracy, existing back pressure valves generally require the use of precision electronic components, such as a combination of pressure sensor + solenoid valve / proportional valve + control circuit, which is costly. However, the back pressure valve in this embodiment does not require electronic components and can meet the long-term reliability requirement of accuracy solely through internal structural design, effectively controlling production costs.

[0062] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A back pressure valve, comprising: a valve seat (100) having an inlet channel (110) and an outlet channel (120) respectively formed therein; a valve cover (200) installed in cooperation with the valve seat (100) and forming a cavity with the valve seat (100); a valve core assembly installed inside the valve seat (100) and separating the cavity into a first accommodating cavity (10) and a second accommodating cavity (20), the valve core assembly being capable of blocking a first port (121) of the outlet channel (120) at the first accommodating cavity (10); characterized in that further comprising: an adjusting assembly located in the second accommodating cavity (20), the adjusting assembly comprising a resilient member (410) and a first limiting member (420) coaxially arranged, the first limiting member (420) being cooperatively arranged between the inner side wall surface of the valve cover (200), the inner side wall surface of the valve cover (200) limiting the tendency of the first limiting member (420) to move in a non-axial direction; the adjusting assembly further comprising a second limiting member (430) coaxial with the resilient member (410), the lower wall surface of the second limiting member (430) being fixedly connected to the valve core assembly, the second limiting member (430) comprising a second limiting structure, the first limiting member (420) comprising a first limiting structure, one end of the resilient member (410) being fixedly connected to the second limiting structure and the other end being fixedly connected to the first limiting structure; the gap between the outer peripheral side wall of the first limiting member (420) and the inner side wall of the valve cover (200) being ≤0.5mm, and the outer wall surface of the second limiting member (430) leaving a gap of 1mm-5mm with the inner wall surface of the valve cover (200).

2. The back pressure valve of claim 1, wherein, the first limiting structure being a first limiting boss (422) and / or a first limiting groove, and the side wall surface of the resilient member (410) abutting against the first limiting structure.

3. The back pressure valve of claim 1, wherein, the second limiting structure comprising a second limiting boss (431) inserted into the resilient member (410).

4. The back pressure valve of claim 1, wherein, the second limiting structure comprising a limiting side wall (432) arranged around the outer edge of the second limiting member (430), the inner side wall surface of the limiting side wall (432) abutting against the outside of the resilient member (410).

5. The back pressure valve of claim 1, wherein, further comprising an adjusting member (441), the valve cover (200) having an installation hole (210) formed in the upper portion thereof, the adjusting member (441) being inserted into the installation hole (210), the lower end of the adjusting member (441) abutting against the first limiting member (420) and being capable of sliding the first limiting member (420) to move the first limiting member (420) closer to or further away from the valve core assembly.

6. The back pressure valve of claim 5, wherein, the adjusting member (441) being a screw, the installation hole (210) being a threaded hole, and the adjusting member (441) being threadedly connected to the installation hole (210).

7. The back pressure valve according to any one of claims 1 to 6, characterized in that The valve core assembly comprises an elastic diaphragm (310) and a valve core body (320), the elastic diaphragm (310) separates the cavity into a first containing cavity (10) and a second containing cavity (20), the valve core body (320) is installed on the lower wall surface of the elastic diaphragm (310), and the bottom of the valve core body (320) is used for plugging the first port (121).

8. The back pressure valve of claim 7, wherein, The bottom of the valve core body (320) is provided with an elastic sealing piece (321).

9. The back pressure valve of claim 7, wherein, The lower wall surface of the elastic diaphragm (310) is provided with a mounting boss (311).

10. The back pressure valve according to any one of claims 1-6, characterized in that The valve cover (200) is provided with a pressure relief through hole (220), and the inside of the valve cover (200) is in communication with the outside atmosphere through the pressure relief through hole (220).

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