A low-pressure automatic cut-off valve

Abstract

The present invention discloses a low-pressure automatic cut-off valve, comprising: a cylinder and a valve body. A piston is arranged in the cylinder, a pressure-regulating spring is arranged at the top of the piston, the upper end of the pressure-regulating spring abuts against the top of the cylinder, the bottom of the piston is connected with a hollow valve rod, the upper end of the valve rod communicates with the lower cavity of the cylinder, and the lower end of the valve rod penetrates into the valve body from the bottom of the cylinder; an air inlet channel and an air outlet channel are arranged in the valve body, the air inlet channel communicates with the lower end of the valve rod, a valve flap is arranged at the lower end of the valve rod, and the valve flap abuts against and blocks the air outlet channel. The embodiment of the present invention utilizes the acting force of air pressure on the piston and the reaction force of the pressure-regulating spring on the piston to sense the air pressure change. When the air pressure is lower than a certain critical value and cannot push the piston to move the valve flap away or even the air pressure is lower, the valve flap will automatically block the air outlet channel to achieve the cut-off of the passage. The opening and closing of the valve can quickly and automatically respond to the change of the air pressure in the pipeline, avoiding danger; without electric control, it is also applicable in remote and powerless working environments.

Description

Technical Field

[0001] The present invention relates to the technical field of control valves, and particularly to a low-pressure automatic cut-off valve. Background Art

[0002] A cut-off valve is a common type of valve, which is a device used to control or cut off the movement of fluids (such as water, air, oil, etc.). Its working principle is based on the valve changing the size of the passage or closing the passage by moving internal components. The internal structure of a traditional manual cut-off valve usually consists of components such as a valve body, a valve cover, a valve core or valve plate, and a sealing ring, and is controlled by a handle or knob. By rotating or pushing and pulling, components such as bolts, spheres, discs, or pistons in the valve are moved, so that the valve core or valve plate will fit tightly with the valve seat, thereby preventing the flow of fluid and the valve is in the closed state; and when the valve needs to be opened, the valve core or valve plate will be pushed or rotated, thus opening the valve and allowing the fluid to pass through.

[0003] There are also some automatic cut-off valves on the market, which achieve automatic control through built-in electronic devices such as sensors, actuators, and motors. For example, during the operation of a low-temperature liquefied carbon dioxide gas pipeline equipment at the upstream end, the air pressure in the pipeline must not be lower than a certain pressure value, otherwise dry ice is likely to form in the pipeline, resulting in pipeline blockage and potential safety hazards.

[0004] However, for such existing automatic cut-off valves during operation, the signal transmission of their sensors, the operation execution of actuators, the startup of motors, etc. all require a certain reaction time, making the operation of cutting off the valve unable to be timely and rapid, accompanied by certain production risks; and the start and stop of their operating functions are also affected by the presence or absence of electricity, which is limited in use in remote areas such as construction sites and gasification stations. Summary of the Invention

[0005] The purpose of the present invention is to provide a low-pressure automatic cut-off valve to improve the speed of valve cutting and break through the use limitation of existing power-controlled valves in remote areas.

[0006] To achieve the above purpose, the present invention provides the following technical solution: A low-pressure automatic cut-off valve, comprising: a cylinder and a valve body, the bottom of the cylinder is connected to the top of the valve body;

[0007] A piston is arranged in the cylinder, the side surface of the piston slidably abuts against the inner wall of the cylinder, dividing the inner cavity of the cylinder into an upper cavity and a lower cavity. A pressure regulating spring is arranged on the top of the piston, the upper end of the pressure regulating spring abuts against the inner wall of the top of the cylinder, the bottom of the piston is connected with a hollow valve rod, the upper end of the valve rod communicates with the lower cavity of the cylinder, and the lower end of the valve rod passes through the bottom of the cylinder and penetrates into the valve body from the top of the valve body;

[0008] An air inlet passage and an air outlet passage are provided inside the valve body. The air inlet passage is communicated with the lower end of the valve stem. A valve flap is provided at the lower end of the valve stem, and the valve flap abuts against and blocks the air outlet passage.

[0009] After the air inlet passage is communicated with an external air inlet device, gas enters the lower chamber of the cylinder through the valve stem and generates an upward acting force on the bottom of the piston, causing the piston to upwardly compress the pressure regulating spring. When the acting force of the gas on the bottom of the piston is greater than the reaction force of the pressure regulating spring on the top of the piston, the pressure regulating spring contracts, the piston slides upward and drives the valve stem, and the valve stem lifts the valve flap to separate the valve flap from the air outlet passage, so that the air inlet passage is communicated with the air outlet passage.

[0010] Preferably, an air outlet hole is provided at the upper end of the valve stem, and the air outlet hole is communicated with the lower chamber. An air inlet hole is provided at the lower end of the valve stem, and the air inlet hole is communicated with the air inlet port.

[0011] Preferably, an upper cylinder head is connected to the upper end of the cylinder in a covering manner, and a lower cylinder head is connected to the lower end of the cylinder body in a covering manner; a lower valve cover is connected to the lower end of the valve body in a covering manner, and an upper valve cover is connected to the upper end of the valve body in a covering manner, and the upper valve cover is connected to the lower cylinder head.

[0012] Preferably, a pressure regulating rod is threadedly connected to the upper cylinder head. The lower end of the pressure regulating rod passes through the upper cylinder head and is connected to the top of the pressure regulating spring for adjusting the compression degree of the pressure regulating spring; a locking nut is provided at the upper end of the pressure regulating rod, and a cap is provided outside the locking nut, and the cap is threadedly connected to the upper cylinder head.

[0013] Preferably, air vent holes are axially communicated at both ends of the pressure regulating rod to communicate the upper chamber of the cylinder body with the outside.

[0014] Preferably, first sealing rings are provided at both the connection between the cylinder and the upper cylinder head and the connection between the cylinder and the lower cylinder head; a fastening screw is connected between the upper cylinder head and the lower cylinder head.

[0015] Preferably, second sealing rings are provided at both the connection between the valve body and the upper valve cover and the connection between the valve body and the lower valve cover.

[0016] Preferably, third sealing rings are provided at both the connection between the valve stem and the lower cylinder head and the connection between the valve stem and the upper valve cover.

[0017] Preferably, a fourth sealing ring is also circumferentially provided on the side surface of the piston, and the fourth sealing ring abuts against the inner wall of the cylinder body.

[0018] Preferably, a fifth sealing ring is provided at the connection between the valve flap and the air outlet channel.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] 1. By connecting a piston mechanism to the valve flap and using a hollow valve stem connected to the piston to communicate the air inlet channel with the lower cavity of the cylinder where the piston is located, the air pressure of the inlet air is used to push the piston to move and drive the valve flap to move, thereby realizing the function of controlling the opening and closing of the air outlet channel; and then by setting a pressure regulating spring on the top of the piston to limit the upward movement of the piston, the air pressure acting on the piston and the reaction force of the pressure regulating spring on the piston are used to sense the air pressure change. When the air pressure is lower than a certain critical value and cannot push the piston to move the valve flap away, or even when the air pressure is lower, the valve flap will automatically block the air outlet channel to cut off the passage. The opening and closing of the valve can quickly and automatically respond to the change of the air pressure in the pipeline, avoiding danger. At the same time, no power control is required, and it can also be used in working environments such as remote and powerless construction sites and gasification stations. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the drawings:

[0022] Figure 1 is a schematic cross-sectional view of the low-pressure automatic cut-off valve proposed by the present invention in the closed state of the air inlet channel and the air outlet channel;

[0023] Figure 2 is a schematic cross-sectional view of the low-pressure automatic cut-off valve proposed by the present invention in the connected state of the air inlet channel and the air outlet channel.

[0024] Reference numerals:

[0025] 10. Cylinder; 11. Piston; 111. Fourth sealing ring; 12. Pressure regulating spring; 13. Upper cylinder head; 14. Lower cylinder head; 15. Pressure regulating rod; 151. Vent hole; 16. Locking nut; 17. Cap; 18. First sealing ring; 19. Fastening screw;

[0026] 20. Valve body; 21. Air inlet channel; 22. Air outlet channel; 23. Upper valve cover; 24. Lower valve cover; 25. Second sealing ring;

[0027] 30. Valve stem; 301. Air inlet hole; 302. Air outlet hole; 31. Valve flap; 311. Fifth sealing ring; 32. Third sealing ring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. In addition, the terms "first", "second", "third", "upper, lower, left, right", etc. are only used for descriptive purposes, in order to facilitate the description of the present invention and simplify 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. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and cannot be understood as a limitation, indication or implication of the relative importance of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances. At the same time, in the description of the present invention, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0029] The implementation of the present invention will be described in detail below in conjunction with specific embodiments.

[0030] As Figure 1-2 shown, it is an embodiment provided by the present invention.

[0031] An embodiment of the present invention provides a low-pressure automatic cut-off valve, including: a cylinder 10 and a valve body 20. The bottom of the cylinder 10 is connected to the top of the valve body 20. Specifically, an upper cylinder head 13 is hermetically connected to the upper end of the cylinder 10, and a lower cylinder head 14 is hermetically connected to the lower end of the cylinder body, which is convenient for the installation and maintenance of the internal parts of the cylinder 10. First sealing rings 18 are provided at the connection between the cylinder 10 and the upper cylinder head 13 and at the connection between the cylinder 10 and the lower cylinder head 14, so as to ensure the airtightness inside the cylinder 10. A fastening screw 19 is connected between the upper cylinder head 13 and the lower cylinder head 14, which can adjust the tightness of the upper cylinder head 13 and the lower cylinder head 14 being hermetically connected, and further ensure the airtightness inside the cylinder 10. A lower valve cover 24 is hermetically connected to the lower end of the valve body 20, and an upper valve cover 23 is hermetically connected to the upper end of the valve body 20, which is convenient for the installation and maintenance of the internal parts of the valve body 20. Second sealing rings 25 are provided at the connection between the valve body 20 and the upper valve cover 23 and at the connection between the valve body 20 and the lower valve cover 24 to ensure the airtightness inside the valve body 20. The upper valve cover 23 is connected to the lower cylinder head 14, and it is only necessary to ensure that the cylinder 10 and the valve body 20 do not loosen and separate.

[0032] A piston 11 is arranged inside a cylinder 10. The side of the piston 11 is in sliding contact with the inner wall of the cylinder 10. A fourth sealing ring 111 is also arranged around the side of the piston 11. The fourth sealing ring 111 is in contact with the inner wall of the cylinder block, separating the inner cavity of the cylinder 10 into an upper cavity and a lower cavity. A pressure regulating spring 12 is arranged on the top of the piston 11. The upper end of the pressure regulating spring 12 is in contact with the inner wall of the top of the cylinder 10. The function of the fourth sealing ring 111 is to prevent gas from leaking from the lower cavity of the cylinder 10 into the upper cavity and generating a downward acting force on the piston 11, preventing it from destroying the balance of the pipeline air pressure and the relative acting force of the pressure regulating spring 12 on the piston 11. The bottom of the piston 11 is connected to a hollow valve rod 30. The upper end of the valve rod 30 communicates with the lower cavity of the cylinder 10. Specifically, an air outlet hole 302 is arranged at the upper end of the valve rod 30, and the air outlet hole 302 communicates with the lower cavity. The lower end of the valve rod 30 passes through the bottom of the cylinder 10 and penetrates into the top of the valve body 20. Third sealing rings 32 are arranged at the connection between the valve rod 30 and the lower cylinder head 14 and at the connection between the valve rod 30 and the upper valve cover 23 to prevent gas from leaking from the valve body 20 or the lower cavity of the cylinder 10 during the movement of the valve rod 30 and ensure their respective airtightness. An air inlet passage 21 and an air outlet passage 22 are arranged inside the valve body 20. The air inlet passage 21 communicates with the lower end of the valve rod 30. Specifically, an air inlet hole 301 is arranged at the lower end of the valve rod 30, and the air inlet hole 301 communicates with the air inlet port, thereby connecting the air inlet passage 21 with the lower cavity of the cylinder 10. Gas can enter the lower cavity of the cylinder 10 from the air inlet passage 21 through the hollow valve rod 30, thereby pushing the piston 11 to move. A valve flap 31 is arranged at the lower end of the valve rod 30. The valve flap 31 abuts against and blocks the air outlet passage 22. Controlling the separation or connection between the valve flap 31 and the air outlet passage 22 can control the connection or closure between the air inlet passage 21 and the air outlet passage 22. A fifth sealing ring 311 is arranged at the connection between the valve flap 31 and the air outlet passage 22 to ensure that the valve flap 31 can seal the air outlet passage 22 and prevent gas leakage. Specifically, the bottom of the valve flap 31 has a downward conical surface. The lower the valve flap 31 is pressed, the tighter the air outlet passage 22 is blocked. The fifth sealing ring 311 can be arranged at the bottom of the valve flap 31 or at the port of the air outlet passage 22.

[0033] After the air inlet passage 21 is connected to an external air inlet device, gas enters the lower cavity of the cylinder 10 through the valve rod 30 and generates an upward acting force on the bottom of the piston 11, causing the piston 11 to upwardly compress the pressure regulating spring 12; as Figure 2 shown, when the acting force of the gas on the bottom of the piston 11 is greater than the reaction force of the pressure regulating spring 12 on the top of the piston 11, the pressure regulating spring 12 contracts, the piston 11 slides upward and drives the valve rod 30, and the valve rod 30 lifts the valve flap 31 to separate the valve flap 31 from the air outlet passage 22, making the air inlet passage 21 communicate with the air outlet passage 22; as Figure 1As shown, when the air pressure is lower than a certain critical value and cannot push the piston 11 to move the valve flap 31 away, or even when the air pressure is lower, the valve flap 31 will automatically block the air outlet channel 22 to cut off the passage. The manufacturer can preset the elastic force of the pressure regulating spring 12 during production and installation to determine the air pressure critical value of this low-pressure automatic cut-off valve. In the embodiment of the present invention, the upward movement of the piston 11 is restricted by the pressure regulating spring 12 provided on the top of the piston 11, so as to realize the perception of air pressure changes by using the acting force of the air pressure on the piston 11 and the reaction force of the pressure regulating spring 12 on the piston 11. When the air pressure is lower than a certain critical value and cannot push the piston 11 to move the valve flap 31 away, or even when the air pressure is lower, the valve flap 31 will automatically block the air outlet channel 22 to cut off the passage. The opening and closing of the valve can quickly and automatically respond to the change of the air pressure in the pipeline, avoiding danger. At the same time, without electric control, it can also be used in working environments such as remote and powerless construction sites and gasification stations. The user can also flexibly set it according to the pressure gauges upstream and downstream of the pipeline and production requirements.

[0034] Furthermore, a pressure regulating rod 15 is threadedly connected to the upper cylinder head 13. The lower end of the pressure regulating rod 15 passes through the upper cylinder head 13 and is connected to the top of the pressure regulating spring 12 for adjusting the compression degree of the pressure regulating spring 12. The user can flexibly set it according to the pressure gauges upstream and downstream of the pipeline and production requirements. When setting the contraction degree of the pressure regulating spring 12 corresponding to the critical value air pressure, the user only needs to rotate the pressure regulating rod 15 to adjust the pressure regulating spring 12, and the operation is very convenient and has strong applicability. A locking nut 16 is provided at the upper end of the pressure regulating rod 15. After setting the contraction degree of the pressure regulating spring 12, the locking nut 16 can be used to further limit it to prevent the pressure regulating rod 15 from loosening. A cap 17 is provided outside the locking nut 16, and the cap 17 is threadedly connected to the upper cylinder head 13 to protect the pressure regulating rod 15 from being affected by external impact. It is worth mentioning that air vent holes 151 are axially communicated at both ends of the pressure regulating rod 15 to connect the upper cavity of the cylinder body with the outside. If a small amount of gas enters the upper cavity of the cylinder 10 through the fourth sealing ring 111 outside the piston 11 during the long-term working state of the cylinder 10, it can be discharged to the outside of the cylinder 10 through the air vent holes 151 in the pressure regulating rod 15, avoiding the generation of a downward acting force in the upper cavity of the cylinder 10 and destroying the pressure balance between the upper and lower sides of the piston 11.

[0035] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. A low-pressure automatic cut-off valve, characterized in that, Comprising: A cylinder (10) and a valve body (20), the bottom of the cylinder (10) being connected to the top of the valve body (20); A piston (11) is arranged inside the cylinder (10), the side surface of the piston (11) slidingly abuts against the inner wall of the cylinder (10), dividing the inner cavity of the cylinder (10) into an upper cavity and a lower cavity. A pressure regulating spring (12) is arranged on the top of the piston (11), the upper end of the pressure regulating spring (12) abutting against the inner wall of the top of the cylinder (10). The bottom of the piston (11) is connected with a hollow valve rod (30), the upper end of the valve rod (30) communicating with the lower cavity of the cylinder (10), and the lower end of the valve rod (30) passing through the bottom of the cylinder (10) and penetrating into the top of the valve body (20); An air inlet passage (21) and an air outlet passage (22) are arranged inside the valve body (20), the air inlet passage (21) communicating with the lower end of the valve rod (30). A valve flap (31) is arranged at the lower end of the valve rod (30), the valve flap (31) abutting against and blocking the air outlet passage (22); After the air inlet passage (21) communicates with an external air inlet device, gas enters the lower cavity of the cylinder (10) through the valve rod (30), and generates an upward acting force on the bottom of the piston (11), causing the piston (11) to upwardly compress the pressure regulating spring (12); when the acting force of the gas on the bottom of the piston (11) is greater than the reaction force of the pressure regulating spring (12) on the top of the piston (11), the pressure regulating spring (12) contracts, the piston (11) slides upward and drives the valve rod (30), and the valve rod (30) lifts the valve flap (31) to separate the valve flap (31) from the air outlet passage (22), so that the air inlet passage (21) is communicated with the air outlet passage (22); An air outlet hole (302) is arranged at the upper end of the valve rod (30), the air outlet hole (302) communicating with the lower cavity, and an air inlet hole (301) is arranged at the lower end of the valve rod (30), the air inlet hole (301) communicating with the air inlet passage (21); The upper end of the cylinder (10) is hermetically connected with an upper cylinder head (13), and a pressure regulating rod (15) is threadedly connected to the upper cylinder head (13). Vent holes (151) are axially communicated at both ends of the pressure regulating rod (15), so that the upper cavity of the cylinder (10) is communicated with the outside; 2. The low-pressure automatic cut-off valve according to claim 1, wherein, The lower end of the cylinder (10) is hermetically connected with a lower cylinder head (14); the lower end of the valve body (20) is hermetically connected with a lower valve cover (24), the upper end of the valve body (20) is hermetically connected with an upper valve cover (23), and the upper valve cover (23) is connected with the lower cylinder head (14).

3. The low-voltage automatic cut-off valve according to claim 2, characterized in that, The lower end of the pressure regulating rod (15) passes through the upper cylinder head (13) and is connected to the top of the pressure regulating spring (12) for adjusting the compression degree of the pressure regulating spring (12); a locking nut (16) is arranged at the upper end of the pressure regulating rod (15), a cap (17) is arranged outside the locking nut (16), and the cap (17) is threadedly connected to the upper cylinder head (13).

4. The low-pressure automatic cut-off valve according to claim 3, characterized in that, First sealing rings (18) are arranged at the joints of the cylinder (10) and the upper cylinder head (13) and at the joints of the cylinder (10) and the lower cylinder head (14); a fastening screw rod (19) is connected between the upper cylinder head (13) and the lower cylinder head (14).

5. The low-pressure automatic cut-off valve according to claim 4, characterized in that, Second sealing rings (25) are arranged at the joints of the valve body (20) and the upper valve cover (23) and at the joints of the valve body (20) and the lower valve cover (24).

6. The low-pressure automatic cut-off valve according to claim 5, characterized in that, Third sealing rings (32) are arranged at the joints of the valve rod (30) and the lower cylinder head (14) and at the joints of the valve rod (30) and the upper valve cover (23).

7. The low-pressure automatic cut-off valve according to claim 1, characterized in that, A fourth sealing ring (111) is also arranged around the side of the piston (11), and the fourth sealing ring (111) abuts against the inner wall of the cylinder (10).

8. The low-pressure automatic cut-off valve according to claim 1, characterized in that, A fifth sealing ring (311) is arranged at the joint of the valve flap (31) and the air outlet channel (22).

Images