Bellows-based check valve

Abstract

The present invention provides a check valve based on a corrugated pipe. The check valve based on the corrugated pipe includes a valve seat assembly, a pressing block, a housing, an inlet joint, a valve core, an outlet joint, a spring, and an orifice plate. The housing is installed on the inlet joint, and the housing and the inlet joint form a first flow channel. A valve core installation position is provided on the housing, and the valve core installation position is outside the first flow channel. The valve core is installed in the valve core installation position. A flow channel hole is provided on the housing. The outlet joint and the housing form a first chamber, and the valve seat assembly, the spring, and the orifice plate are all arranged in the first chamber. An orifice plate installation position is provided on the valve seat assembly, and the orifice plate is installed on the orifice plate installation position. One end of the spring is connected to the valve seat assembly, and the other end is connected to the inlet joint. The present invention provides a high-performance check valve that not only meets the high requirements of low opening, low flow resistance, and low reverse internal leakage, but also can stably operate within a large flow range.

Description

Technical Field

[0001] The present invention relates to the technical field of valves. Specifically, it relates to a bellows check valve, and in particular, it is applicable to the field of space propulsion. More particularly, it relates to a check valve based on a bellows. Background Art

[0002] In the attitude and orbit control propulsion subsystem (hereinafter referred to as the system), a check valve is often used as a component to control the flow direction of the control medium, and is used to prevent the propellant and its vapor in the downstream storage tank from flowing back to the upstream. From a functional perspective, the reverse sealing performance of the check valve is an important indicator, but the opening pressure is a contradictory indicator to it, and a balance needs to be achieved during the design process. In addition, the system does not allow a large pressure drop loss brought by the check valve. A small pressure drop means insufficient energy to maintain the stable opening of the valve flap, especially in the case of small flow conditions. This is the main reason for the frequent problem of the opening stability of the check valve. The above are the design difficulties of the check valve.

[0003] With the popularization of surface tension storage tanks, more and more systems are applying check valves, and at the same time, the performance indicators for check valves are becoming more and more demanding: it is necessary to fully meet the requirements of low opening, low flow resistance, and low reverse internal leakage, and at the same time, it can work stably in a wide flow range. However, the traditional structure can no longer fully meet the system requirements. Therefore, new structures and new methods need to be adopted to further improve the performance of the check valve.

[0004] Looking at the technical status at home and abroad, the design of check valves for the space propulsion field has gradually started to pay attention to anti-chatter vibration, that is, it cannot be stably opened and operated, which is mainly reflected in the vibration and chirping of the valve flap moving parts. Therefore, some check valves with anti-chatter functions have emerged. For example, the patent document CN212928868U discloses a high-pressure and highly reliable anti-chatter check valve, which includes a valve body, a main valve core, a main valve seat, and a return spring. The valve body is provided with a cavity. The main valve seat is detachably fixed to one end of the valve body. The main valve core is placed inside the valve body and is in sliding contact with the valve body. The return spring is placed between the main valve core and the main valve seat, and both ends of the return spring are respectively abutted and connected to the main valve core and the main valve seat. Its characteristics are: a placement groove is coaxially opened at one end of the inner wall of the valve body away from the main valve seat, and a damping ring is clamped in the placement groove. The damping ring is sleeved on the circumferential surface of the main valve core and is abutted and connected to the main valve core, and the damping characteristics of the elastic system are adjusted through the friction force of the damping ring, so as to solve the problem of the resonance of the valve core during the use of the check valve. The cited invention alleviates the chatter problem through damping measures. Currently, most anti-chatter check valves use this method to solve the problem, but in many cases, other performances of the check valve are sacrificed. For example, increasing the damping friction force will increase the opening force of the check valve, and it is also not helpful for improving the reverse sealing performance and reducing the flow resistance. It can be seen that the current mainstream solutions still have deficiencies.

[0005] Patent document CN208967126U discloses a silent one-way valve, belonging to the technical field of valve manufacturing. It solves the problem of high noise of the existing one-way valve. The solution includes a valve body, a guide seat, a valve core, a valve stem, a sealing ring and a spring. The valve seat has a first guide surface and a second guide surface. The first guide surface is connected to the second guide surface. The first guide surface is arranged along the axial direction of the valve body. There is an acute angle between the second guide surface and the axial direction of the valve body. The outer side wall of the valve core has a first positioning surface and a second positioning surface. The first positioning surface is connected to the second positioning surface. The first positioning surface matches the first guide surface and is arranged along the axial direction of the valve body. The second positioning surface matches the second guide surface and there is an acute angle between the second positioning surface and the axial direction of the valve body. However, the focus of this solution is to reduce noise and still cannot meet the requirements of low opening, low flow resistance and low reverse internal leakage. Summary of the Invention

[0006] Aiming at the defects in the prior art, the purpose of the present invention is to provide a one-way valve based on a corrugated pipe and a one-way valve based on a corrugated pipe.

[0007] A one-way valve based on a corrugated pipe according to the present invention is characterized in that it includes a valve seat assembly, a housing, an inlet joint, a valve core, a pressing block, an outlet joint, a spring and an orifice plate;

[0008] The housing is installed on the inlet joint, and the housing and the inlet joint form a first flow channel;

[0009] A valve core installation position is arranged on the housing. The valve core installation position is outside the first flow channel. The valve core is fixed to the housing through a pressing block;

[0010] A flow channel hole is arranged on the housing;

[0011] The outlet joint and the housing form a first chamber. The valve seat assembly, the spring and the orifice plate are all arranged in the first chamber. The first chamber includes an upper chamber, a middle chamber and a lower chamber;

[0012] The outlet joint includes a limiting wall and an outlet joint body. The limiting wall is arranged on the outlet joint body. The limiting wall extends around the axial direction of the outlet joint body to form an annular structure. An orifice plate installation position is arranged on the valve seat assembly. The orifice plate is installed on the orifice plate installation position. One end of the spring is connected to the valve seat assembly, and the other end is connected to the inlet joint. The spring is in a compressed state. A ventilation hole is arranged on the limiting wall;

[0013] The first flow channel is communicated with the upper chamber through the flow channel hole. The middle chamber and the lower chamber are communicated through the ventilation hole. The middle chamber is communicated with the outlet joint.

[0014] Preferably, the bellows-based check valve has an open state and a closed state, and the valve seat assembly has a first state and a second state. When the bellows-based check valve is in the closed state, the valve seat assembly is in the first state, the spring is in the first length, and the valve seat edge of the valve seat assembly fits and seals with the valve core; when the bellows-based check valve is in the open state, the valve seat assembly is in the second state, the spring is in the second length, and the valve seat edge of the valve seat assembly is separated from the valve core;

[0015] The first length is greater than the second length.

[0016] Preferably, the valve seat assembly includes a first flange, a bellows, and a second flange;

[0017] The first flange and the second flange are connected by the bellows, and the second flange is tightly connected to the outlet joint;

[0018] The first flange is provided with a valve seat edge, an orifice plate mounting position, and a movement guiding shaft; the valve seat edge is arranged on one side of the first flange, and the orifice plate mounting position and the movement guiding shaft are arranged on the other side of the first flange; the movement guiding shaft contacts with the limiting wall to form a movement pair.

[0019] The first flange can move between a first position and a second position in the first chamber;

[0020] The first position and the second position are the positions of the first flange when the bellows-based check valve is in the closed state and the open state respectively.

[0021] Preferably, when the valve seat assembly is in the first state, the first flange is located at the first position, the bellows is in the third length, and the valve seat edge fits and seals with the valve core;

[0022] When the valve seat assembly is in the second state, the first flange is located at the second position, the bellows is in the fourth length, and the valve seat edge is separated from the valve core;

[0023] The third length is greater than the fourth length.

[0024] Preferably, one end of the bellows is connected to the first flange and the other end is connected to the second flange.

[0025] Preferably, the bellows is a metal bellows.

[0026] Preferably, 1 throttle hole is provided on the orifice plate.

[0027] Preferably, the second flange is fixed by clamping of the outlet joint with the housing.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention provides a high-performance check valve, which not only meets the high requirements of low opening, low flow resistance and low reverse internal leakage, but also can stably operate within a large flow range.

[0030] 2. The working stability of the present invention: The present invention uses a bellows as a pressure-sensitive element and an actuating member, and the differential pressure between the inlet and outlet is the actuating energy of the bellows. Compared with traditional check valves, the bellows is more sensitive to the differential pressure between the upstream and downstream, and it is easier to maintain a stable opening under small flow conditions. The present invention has a wide flow range, and it has been verified that the large-to-small flow ratio is not less than 4.

[0031] 3. The present invention realizes the balance and improvement of the check valve indexes. The present invention only needs a very small differential pressure between the upstream and downstream to open the bellows check valve, that is, to achieve a lower opening force; through the design of the bellows, the present invention can achieve low reverse internal leakage without sacrificing the opening performance; the opening of the check valve of the present invention is provided with energy by the differential pressure between the upstream and downstream of the check valve, and the required opening differential pressure is much lower than that of traditional check valves. On the premise of not affecting the stable operation of the check valve, a lower flow resistance design (i.e., the differential pressure between the inlet and outlet) can be selected to achieve large flow and small flow resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] By reading the following detailed description of the non-limiting embodiments with reference to the accompanying drawings, other features, objects and advantages of the present invention will become more apparent:

[0033] Figure 1 is a schematic structural diagram of the present invention when it is closed;

[0034] Figure 2 is a schematic structural diagram of the present invention when it is open.

[0035] As shown in the figure:

[0036] DETAILED DESCRIPTION OF THE INVENTION

[0037] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those of ordinary skill in the art can make several changes and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0038] The present invention provides a check valve based on a bellows, such as Figure 1 , Figure 2As shown, it includes a valve seat assembly 1, a housing 2, an inlet joint 3, a valve core 4, a pressing block 5, an outlet joint 6, a spring 7, and an orifice plate 8;

[0039] The housing 2 is installed on the inlet joint 3, and the housing 2 and the inlet joint 3 form a first flow channel 9. A valve core installation position is provided on the housing 2, and the valve core installation position is outside the first flow channel 9. The valve core 4 is installed in the valve core installation position. In a preferred example, the valve core 4 is fixed to the housing 2 through the pressing block 5. A flow channel hole 10 is provided on the housing 2. In a preferred example, several flow channel holes 10 are provided on the housing 2 near the installation position of the valve core 4. The outlet joint 6 and the housing 2 form a first chamber 11. The valve seat assembly 1, the spring 7, and the orifice plate 8 are all arranged in the first chamber 11. The first chamber 11 includes an upper chamber part 1101, a middle chamber part 1102, and a lower chamber part 1103. The outlet joint 6 includes a limiting wall 14 and an outlet joint body 15. The limiting wall 14 is arranged on the outlet joint body 15, and the limiting wall 14 extends around the axis of the outlet joint body 15 to form an annular structure;

[0040] An orifice plate installation position is provided on the valve seat assembly 1, and the orifice plate 8 is installed on the orifice plate installation position. One end of the spring 7 is connected to the valve seat assembly 1, and the other end is connected to the inlet joint 3. The spring 7 is in a compressed state. In a preferred example, the spring 7 is located in the inner hole of the outlet joint 6;

[0041] A vent hole 16 is also provided on the limiting wall 14. The first flow channel 9 is communicated with the upper chamber part 1101 through the flow channel hole 10. The middle chamber part 1102 and the lower chamber part 1103 are communicated through the vent hole 16. The middle chamber part 1102 is communicated with the outlet joint 6. In a preferred example, as Figure 1 shown, the number of the flow channel holes 10 is 2. The first flow channel 9 is respectively communicated with the upper chamber part 1101 and the lower chamber part 1103 through 2 flow channel holes 10. The number of the vent holes 16 is 2. The middle chamber part 1102 is respectively communicated with the upper chamber part 1101 and the lower chamber part 1103 through 2 vent holes 16.

[0042] The check valve based on the bellows has an open state and a closed state. The valve seat assembly 1 has a first state and a second state. When the check valve based on the bellows is in the closed state, the valve seat assembly 1 is in the first state, the spring is in the first length, and the valve seat edge 12 of the valve seat assembly 1 is in sealing fit with the valve core 4. When the check valve based on the bellows is in the open state, the valve seat assembly 1 is in the second state, the spring is in the second length, and the valve seat edge 12 of the valve seat assembly 1 is separated from the valve core 4. The first length is greater than the second length.

[0043] The valve seat assembly 1 includes a first flange 101, a bellows 102, and a second flange 103; one end of the spring 7 is connected to the first flange 101, and the first flange 101 and the second flange 103 are connected by the bellows 102. Specifically, one end of the bellows 102 is connected to the first flange 101, and the other end is connected to the second flange 103. The second flange 103 is fixedly connected to the outlet joint 6. Specifically, one end of the outlet joint 6 is connected to the second flange 103. In a preferred example, the second flange 103 is fixed by clamping the outlet joint 6 to the housing 2. Preferably, a sealing gasket is provided when the outlet joint 6 is clamped to the housing 2 to further ensure the sealing performance. Both the bellows 102 and the spring 7 are used to provide a pre-tightening force for the valve seat assembly 1 when the check valve is in the closed state, and to provide a restoring force for the valve seat assembly 1 when the check valve is in the open state.

[0044] The first flange 101 is provided with a valve seat edge 12, an orifice plate mounting position, and a movement guide shaft 13; the valve seat edge 12 is provided on one side of the first flange 101, and the orifice plate mounting position and the movement guide shaft 13 are provided on the other side of the first flange 101; the first flange 101 can move between a first position and a second position within the first chamber 11, and the first position and the second position are the positions of the first flange 101 when the bellows-based check valve is in the closed state and the open state, respectively. In a preferred example, the bellows 102 is a metal bellows, and the bellows 102 is a pressure-sensitive element and an action execution element of the first flange 101. The valve seat assembly 1 is an integrated structure of a throttle orifice, a pressure-sensitive element, and an action execution member.

[0045] When the valve seat assembly 1 is in the first state, the first flange 101 is located at the first position, the bellows 102 is at the third length, and the valve seat edge 12 is in sealing contact with the valve core 4; when the valve seat assembly 1 is in the second state, the first flange 101 is located at the second position, the bellows 102 is at the fourth length, and the valve seat edge 12 is separated from the valve core 4; the third length is greater than the fourth length. The valve core 4, that is, the sealing pair valve core, is located upstream of the valve seat assembly 1, and the valve seat assembly 1, that is, the sealing pair valve seat, is arranged downstream of the valve core 4. The valve seat edge 12 acts with the first flange 101, so the check valve controls the opening and closing of the valve core valve seat sealing pair through the action of the valve seat assembly 1.

[0046] The movement guide shaft 13 is in contact with the limit wall 14 to form a movement mating pair. The movement mating pair can ensure that the first flange 101 moves along the outlet direction. When it moves to the second position, the first flange 101 physically contacts the limit post 14, and this is the maximum opening of the check valve.

[0047] The working principle and process of the present invention are as follows:

[0048] The working medium enters from the inlet joint 3. When the inlet reaches a certain pressure, it overcomes the pre-tightening forces of the main spring 7 and the bellows 102, and the valve seat edge 12 is separated from the valve core 4, that is, the valve seat opens; when the working medium continues to flow and the flow rate gradually increases, the throttling is concentrated at the orifice plate 8, generating a corresponding flow resistance (i.e., the pressure difference between the upstream and downstream of the valve core-valve seat sealing pair), which acts on the bellows 102 and the first flange 101, pushing the first flange 101 to continuously move towards the outlet direction until it finally reaches a stable opening state.

[0049] When the working medium continues to flow and the flow rate gradually decreases, the flow resistance decreases accordingly. When it decreases to a level insufficient to overcome the combined forces of the main spring 7 and the bellows 102, the first flange 101 gradually moves towards the inlet direction, and finally the valve seat edge 12 fits and seals with the valve core 4, achieving a reverse sealing effect; after the one-way valve is closed, when the pressure downstream of the valve core-valve seat sealing pair (i.e., the pressure in the outlet joint 6) gradually decreases, and the combined force of the pre-tightening forces of the main spring 7, the bellows 102, and the downstream medium pressure is less than the force acting on the bellows 102 by the upstream medium, the one-way valve opens and works again at this time.

[0050] Among them, the principle of the bellows 102 is as follows: As shown in Figure 2 , the bellows 102 serves to isolate the working media with different pressure differences. Here, A represents the working medium before passing through the valve core-valve seat sealing pair, which has a first pressure, and B represents the working medium after passing through the valve core-valve seat sealing pair, which has a second pressure. In Figure 2 , there is a pressure difference between the first and second pressures. One side of the bellows 102 contacts the working medium upstream of the valve core-valve seat sealing pair (i.e., the inlet), while the other side of the bellows 102 contacts the working medium downstream of the valve core-valve seat sealing pair (i.e., the outlet). Therefore, the pressure difference between the upstream and downstream of the valve core-valve seat sealing pair (i.e., the inlet and outlet pressure difference) is the driving energy for the movement of the bellows 102.

[0051] The working principle of the orifice plate 8 is as follows: During operation, the throttling of the one-way valve is mainly concentrated at the orifice plate 8. One throttling hole is provided on the orifice plate 8, and the size of the throttling hole can be used to adjust the pressure difference between the upstream and downstream of the sealing pair (i.e., the inlet and outlet pressure difference).

[0052] The present invention provides a bellows check valve, which can comprehensively achieve high performance of low opening, low flow resistance and low reverse internal leakage, and can also work stably in a relatively wide flow range, especially solving the problem of unstable opening of the check valve under small flow conditions. The present invention provides a high-performance check valve, which not only meets the high requirements of low opening, low flow resistance and low reverse internal leakage, but also can work stably in a large flow range, especially solving the problem of unstable opening of the check valve under small flow conditions. In addition, the present invention realizes the comprehensive balance and improvement of the check valve indexes. The bellows check valve of the present invention can be opened with only a very small upstream and downstream pressure difference, that is, a lower opening force is achieved; increasing the pressure-sensitive area of the bellows means that more spring force can be overcome, and there is more design space to increase the spring preload, that is, to increase the sealing specific pressure of the valve core and valve seat sealing pair. Therefore, the bellows check valve can achieve low reverse internal leakage without sacrificing the opening force performance; the opening of this check valve is provided with energy by the pressure difference between the inner and outer cavities of the bellows, and the required opening pressure difference is much lower than that of the traditional check valve. Without affecting the stable operation of the check valve, a lower flow resistance design (i.e., the pressure difference between the inlet and outlet) can be selected to achieve large flow and small flow resistance.

[0053] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application.

[0054] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A check valve based on a corrugated pipe, characterized in that, it includes a valve seat assembly (1), a housing (2), an inlet joint (3), a valve core (4), a pressing block (5), an outlet joint (6), a spring (7) and an orifice plate (8); The housing (2) is installed on the inlet joint (3), and the housing (2) and the inlet joint (3) form a first flow channel (9); A valve core installation position is provided on the housing (2), and the valve core installation position is outside the first flow channel (9). The valve core (4) is fixed to the housing (2) through the pressing block (5); A flow channel hole (10) is provided on the housing (2); The outlet joint (6) and the housing (2) form a first chamber (11), and the valve seat assembly (1), the spring (7) and the orifice plate (8) are all arranged in the first chamber (11); The first chamber (11) includes an upper chamber part (1101), a middle chamber part (1102) and a lower chamber part (1103); The outlet joint (6) includes a limiting wall (14) and an outlet joint body (15). The limiting wall (14) is arranged on the outlet joint body (15), and the limiting wall (14) extends around the axis of the outlet joint body (15) to form an annular structure; An orifice plate installation position is provided on the valve seat assembly (1), and the orifice plate (8) is installed in the orifice plate installation position; One end of the spring (7) is connected to the valve seat assembly (1), and the other end is connected to the inlet joint (3). The spring (7) is in a compressed state; A vent hole (16) is provided on the limiting wall (14); The first flow channel (9) is communicated with the upper chamber part (1101) through the flow channel hole (10), and the middle chamber part (1102) and the lower chamber part (1103) are communicated through the vent hole (16); The middle chamber part (1102) is communicated with the outlet joint (6); The check valve based on the corrugated pipe has an open state and a closed state. The valve seat assembly (1) has a first state and a second state. When the check valve based on the corrugated pipe is in the closed state, the valve seat assembly (1) is in the first state, the spring is in the first length, and the valve seat edge (12) of the valve seat assembly (1) is in contact and sealed with the valve core (4); When the check valve based on the corrugated pipe is in the open state, the valve seat assembly (1) is in the second state, the spring is in the second length, and the valve seat edge (12) of the valve seat assembly (1) is separated from the valve core (4); The first length is greater than the second length; The valve seat assembly (1) includes a first flange (101), a corrugated pipe (102) and a second flange (103); The first flange (101) and the second flange (103) are connected by the corrugated pipe (102), and the second flange (103) is tightly connected to the outlet joint (6); The first flange (101) is provided with a valve seat edge (12), an orifice plate mounting position, and a movement guide shaft (13); the valve seat edge (12) is arranged on one side of the first flange (101), and the orifice plate mounting position and the movement guide shaft (13) are arranged on the other side of the first flange (101); the movement guide shaft (13) contacts with the limit wall (14) to form a movement pair. The first flange (101) can move between a first position and a second position within the first chamber (11). The first position and the second position are the positions of the first flange (101) when the bellows-based one-way valve is in a closed state and an open state, respectively. When the valve seat assembly (1) is in the first state, the first flange (101) is located at the first position, the bellows (102) is at the third length, and the valve seat edge (12) is in sealing contact with the valve core (4). When the valve seat assembly (1) is in the second state, the first flange (101) is located at the second position, the bellows (102) is at the fourth length, and the valve seat edge (12) is separated from the valve core (4). The third length is greater than the fourth length.

2. The bellows-based one-way valve according to claim 1, wherein, One end of the bellows (102) is connected to the first flange (101), and the other end is connected to the second flange (103).

3. The bellows-based one-way valve according to claim 1, wherein, The bellows (102) is a metal bellows.

4. The bellows-based one-way valve according to claim 1, wherein, One throttle hole is provided on the orifice plate (8).

5. The bellows-based one-way valve according to claim 1, wherein, The second flange (103) is fixed by being clamped by the outlet joint (6) and the housing (2).

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