Stop valve

Abstract

The stop valve comprises a valve body and a valve element, one end of the valve body is provided with a large port, the other end of the valve body is provided with a small port, a cylindrical inner cavity is formed in the valve body, a first sealing face is formed at the position, on the periphery of the small port, of the bottom of the inner cavity, and a circulation hole is formed in the position, close to the small port, of the wall of the inner cavity; the valve element and one end of the small port of the valve body form a support through a spring, the valve element is provided with a second sealing face right facing the first sealing face, the valve element is provided with a liquid passing cavity right facing the large port of the valve body, a liquid passing hole is formed in the cavity wall of the liquid passing cavity, and a throttling hole is formed in the cavity bottom of the liquid passing cavity and right faces the small port. The sealing structure is simple and reasonable in structure and low in manufacturing cost, the second sealing face of the valve element and the first sealing face of the valve body are rapidly attached to form sealing, so that the blocking effect on oil liquid is achieved, the sealing structure is formed by attaching the two sealing faces, the blocking effect of the sealing structure is guaranteed, and the safety of a hydraulic system is guaranteed.

Description

Technical Field

[0001] This utility model belongs to the field of control valves, and in particular relates to a shut-off valve. Background Technology

[0002] Safety valves in hydraulic systems are important components of hydraulic cylinders in lifting equipment. They are mainly used to prevent uncontrolled descent of the hydraulic cylinder in the event of a sudden rupture and pressure release of an oil pipe, thereby preventing safety accidents.

[0003] Commonly used shut-off valve structures include: Figure 4 As shown, the valve core 2 inside the valve body 1 is provided with a conical sealing part 25, which corresponds to the small port 12 of the valve body. In the event of a sudden pressure release caused by a sudden situation such as a pipe burst in the hydraulic system, the hydraulic oil in the cylinder pushes the valve core 2 to perform a closing action. The conical sealing part 25 of the valve core is inserted into the small port 12 and seals the small port 12, thus blocking the hydraulic oil. At this time, the hydraulic oil can only flow through the throttle hole 23 of the valve core to prevent a large amount of hydraulic oil from being lost.

[0004] However, it was found during use that the sealing structure for blocking hydraulic fluid is a linear sealing structure formed after the conical sealing part is inserted into the small port of the valve body. Due to manufacturing tolerances and assembly errors, it is difficult to ensure that the conical sealing part and the small port seal well along the entire circumference. There are often local gaps, resulting in poor blocking effect. Therefore, targeted improvements are needed. Utility Model Content

[0005] In view of this, the present invention aims to provide a shut-off valve to overcome the deficiencies of the prior art.

[0006] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0007] A shut-off valve, comprising:

[0008] The valve body has a large port at one end and a small port at the other end, and has a cylindrical inner cavity inside. Both the large port and the small port are connected to the inner cavity. The diameter of the large port is not smaller than the diameter of the inner cavity, and the diameter of the small port is smaller than the diameter of the inner cavity. A first sealing surface is formed at the bottom of the inner cavity around the small port. A flow hole is formed on the wall of the inner cavity near the small port.

[0009] The valve core is slidably installed in the inner cavity and supported by a spring and one end of the valve body at the small port. A limiting element is set in the inner cavity near the large port corresponding to the valve core. A second sealing surface is set in front of the first sealing surface of the valve core. A liquid passage chamber is set in front of the large port of the valve body. A liquid passage hole is opened in the wall of the liquid passage chamber. A throttling hole is opened in the bottom of the liquid passage chamber and is directly opposite the small port.

[0010] Furthermore, the first sealing surface has an annular groove located adjacent to the inner cavity wall, and the spring is installed in the annular groove.

[0011] Furthermore, the outer end of the valve core is provided with a guide ring, which slides in conjunction with the inner wall of the inner cavity. The spring is sleeved on the outside of the valve core, with one end abutting against the guide ring and the other end abutting against the valve body.

[0012] Furthermore, the valve core has a flow guide on its inner outer circumferential surface, and the flow guide has a conical structure.

[0013] Furthermore, 3-5 liquid passage holes are evenly arranged in a square pattern around the circumference.

[0014] Furthermore, the limiting component is a retaining ring, which is installed in a groove opened in the inner wall of the valve body.

[0015] Furthermore, the first sealing surface and the second sealing surface are respectively provided with a polytetrafluoroethylene coating.

[0016] Furthermore, the valve body is made of 45 steel, and the valve core is made of 40Cr steel.

[0017] Compared with the prior art, the shut-off valve of this utility model has the following advantages:

[0018] (1) The present invention has a simple and reasonable structure and low manufacturing cost. It uses a spring to keep the valve core in the open state, so that the valve body cavity and the valve core fluid passage cavity are connected, and the oil flows normally and smoothly. When the hydraulic oil circuit is suddenly depressurized due to sudden conditions such as pipe burst, the oil pressure in the valve body cavity decreases, and the hydraulic oil in the cylinder pushes the valve core to perform the sealing work. The second sealing surface of the valve core and the first sealing surface of the valve body quickly fit together to form a seal. The oil can only flow through the throttling hole of the valve core, preventing the oil from being discharged in large quantities, thereby blocking the oil. Moreover, since the sealing structure is formed by the fit of two sealing surfaces, the blocking effect is guaranteed, ensuring the safety of the hydraulic system.

[0019] (2) In this utility model, the annular groove and guide ring provided with the corresponding spring ensure the stability of spring installation and compression deformation, and improve the stability of valve core movement. Attached Figure Description

[0020] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0021] Figure 1 This is a schematic diagram of a shut-off valve structure according to an embodiment of the present utility model;

[0022] Figure 2 This is a schematic diagram of the valve body structure in an embodiment of the present utility model;

[0023] Figure 3 This is a schematic diagram of the valve core structure in an embodiment of this utility model;

[0024] Figure 4 This is a schematic diagram of an existing shut-off valve structure.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1-Valve body; 11-Flow hole; 12-Small port; 13-First sealing surface; 131-Annular groove; 14-Inner cavity; 15-Large port; 2-Valve core; 21-Liquid passage chamber; 22-Liquid passage hole; 23-Throttle hole; 24-Guide ring; 25-Conical sealing part; 26-Second sealing surface; 27-Flow guide part; 3-Spring; 4-Limiting element. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] A shut-off valve, such as Figure 1 As shown, the valve body 1 includes a valve core 2 that slides axially within it, and the valve body 1 and valve core 2 are supported by a spring 3.

[0029] Valve body 1 structure as follows Figure 2 As shown, it is a 45 steel component with a large port 15 at one end and a small port 12 at the other end. It has a cylindrical inner cavity 14 for installing the valve core 2. Both the large port 15 and the small port 12 communicate with the inner cavity 14. Preferably, the diameter of the large port 15 is the same as the diameter of the inner cavity 14 to improve the ease of machining the large port 15 and the inner cavity 14, as well as the ease of valve core installation. The diameter of the small port 12 is smaller than the diameter of the inner cavity 14, forming a first sealing surface 13 at the periphery of the small port 12 at the bottom of the inner cavity 14. Preferably, the first sealing surface 13 is coated with polytetrafluoroethylene (PTFE), which has good wear resistance and sealing properties. An annular groove 131 is formed on the first sealing surface 13 adjacent to the inner cavity 14 wall, corresponding to the spring 3, for positioning during spring 3 installation. Two flow holes 11 are formed on the inner cavity 14 wall near the small port 12, and the two flow holes 11 are directly opposite each other.

[0030] The valve core 2 is slidably installed in the inner cavity 14 and supported by the spring 3 and one end of the small port of the valve body 1. At this time, one end of the spring 3 is installed in the annular groove 131. The inner cavity 14 is provided with a limiting member 4 near the large port 15 corresponding to the valve core 2. The limiting member 4 is preferably a retaining ring. The retaining ring is installed in the retaining groove opened in the inner wall of the valve body. The limiting member 4 positions the valve core 2 and prevents the valve core 2 from slipping off the valve body 1.

[0031] Valve core 2 is made of 40Cr material, and its structure is as follows: Figure 3As shown, the diameter of valve core 2 is smaller than the aperture of the inner cavity 14 of valve body 1, while the diameter of valve core 2 is larger than the aperture of the small port 12 of valve body 1. Therefore, an annular groove can be formed between valve core 2 and valve body 1, allowing spring 3 to be fitted over valve core 2 and providing a certain guiding effect. This structure also ensures that valve core 2 can be aligned with the first sealing surface 13 of valve body 1 to form a second sealing surface 26, which is coated with polytetrafluoroethylene. When the second sealing surface 26 is in contact with the first sealing surface 13, a seal is formed. Because this sealing structure is a surface-to-surface seal, it ensures good sealing performance, thereby improving the blocking effect of valve core 2 on hydraulic oil. A guide ring 24 is provided at the end of valve core facing away from the second sealing surface 26. The guide ring 24 and the inner cavity 14 are fitted with a clearance to ensure the stability of valve core 2 movement, while the guide ring 24 supports spring 3. After assembly, one end of spring 3 abuts against the guide ring 24, and the other end abuts against the bottom of the annular groove 131, ensuring the stability of spring installation and deformation. A liquid passage chamber 21 is opened at the end of the valve core 2 away from the second sealing surface 26. A throttling orifice 23 is opened at the center of the bottom of the liquid passage chamber 21, and four liquid passage holes 22 are opened on the wall of the liquid passage chamber 21. After assembly, the liquid passage chamber 21 is directly opposite the large port 15 of the valve body 1, and the throttling orifice 23 is directly opposite the small port 12.

[0032] Under normal operating conditions, the valve core 2 is in the open state under the action of the spring 3. At this time, the large port 15, the flow hole 11, the fluid passage chamber 21, the fluid passage hole 22, the inner cavity 14 of the valve body 1, and the small port 12 form a passage, allowing hydraulic oil to flow normally. Once a sudden problem such as a pipe burst occurs in the hydraulic system, causing pressure loss, the hydraulic oil in the cylinder pushes the valve core 2 to close due to the reduced pressure in the inner cavity 14. The second sealing surface 26 of the valve core 2 and the first sealing surface 13 of the valve body 1 fit together to form a seal, cutting off the oil flow. This ensures that the hydraulic oil can only flow through the throttling hole 23 and the small port 12 of the valve core 2, preventing a sudden large-scale leakage of oil.

[0033] In this utility model, the inner end of the valve core 2, that is, the outer circumferential surface of the end facing the first sealing surface 13, is provided with a flow guide 27. The flow guide is a conical structure, which reduces the resistance to the flow of oil and allows the oil to flow smoothly under normal working conditions.

[0034] In this invention, the sealing structure that blocks the oil is a surface-to-surface sealing structure formed by the bonding of the first sealing surface and the second sealing surface. It has a good sealing effect, improves the stability of the shut-off valve function, and ensures the safety of the hydraulic system.

[0035] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A shut-off valve, characterized by: include: The valve body (1) has a large port (15) at one end and a small port (12) at the other end. It has a cylindrical inner cavity (14) inside. The large port (15) and the small port (12) are connected to the inner cavity (14). The diameter of the large port (15) is not smaller than the diameter of the inner cavity (14), and the diameter of the small port (12) is smaller than the diameter of the inner cavity (14). The bottom of the inner cavity (14) has a first sealing surface (13) at the periphery of the small port (12). The cavity wall of the inner cavity (14) has a flow hole (11) near the small port (12). The valve core (2) is slidably installed in the inner cavity (14) and supported by the spring (3) and the small port end of the valve body (1). The inner cavity (14) is provided with a limiting member (4) near the large port position corresponding to the valve core (2). The valve core (2) is provided with a second sealing surface (26) facing the first sealing surface (13). The valve core (2) is provided with a liquid passage chamber (21) facing the large port (15) of the valve body (1). A liquid passage hole (22) is opened in the cavity wall of the liquid passage chamber (21). A throttling hole (23) is opened at the bottom of the liquid passage chamber (21). The throttling hole (23) is facing the small port (12).

2. A shut-off valve according to claim 1, characterised in that: The first sealing surface (13) has an annular groove (131) located adjacent to the cavity wall of the inner cavity (14), and the spring (3) is installed in the annular groove (131).

3. A shut-off valve according to claim 1, characterized in that: The valve core (2) has a guide ring (24) at its outer end. The guide ring (24) slides in cooperation with the inner wall of the inner cavity (14). The spring (3) is sleeved on the valve core (2), with one end abutting against the guide ring (24) and the other end abutting against the valve body (1).

4. A shut-off valve according to claim 1, characterized in that: The valve core (2) has a flow guide (27) on the outer circumferential surface of its inner end, and the flow guide has a conical structure.

5. A shut-off valve according to claim 1, characterized in that: The liquid passage holes (22) are arranged in a square pattern with 3-5 holes evenly distributed around their circumference.

6. A shut-off valve according to claim 1, characterized in that: The limiting component (4) is a retaining ring, which is installed in a groove opened on the inner wall of the valve body.

7. A shut-off valve according to claim 1, characterized in that: The first sealing surface (13) and the second sealing surface (26) are respectively provided with polytetrafluoroethylene coating.

8. A shut-off valve according to claim 1, characterized in that: The valve body (1) is made of 45 steel, and the valve core (2) is made of 40Cr steel.

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