pilot shut-off valve

Abstract

The utility model discloses a pilot stop valve, including main valve body, valve core and pilot valve subassembly, the pilot valve subassembly includes setting on the pilot valve body, hand wheel and the movable setting in the pilot valve body inside and with hand wheel connection's valve stem, set up the composite sealing mechanism on valve stem, the material of valve core is 3Cr13, and the sealing surface of valve core is conical surface. The utility model discloses a pilot stop valve, and valve core adopts 3Cr13 material and is made, and the hard sealing is formed between main valve body and valve core, can improve the sealing performance and reliability of pilot stop valve, and the valve stem of pilot valve subassembly sets up the composite sealing mechanism simultaneously, can improve the sealing performance and reliability of pilot valve subassembly.

Description

Technical Field

[0001] This invention belongs to the technical field of hydraulic supports for fully mechanized coal mining. Specifically, this utility model relates to a pilot shut-off valve. Background Technology

[0002] Chinese Patent Application No. 201220572255.1 discloses a self-filtering slide valve type high-pressure pilot shut-off valve, including a hydraulic pilot control part and a main valve part; the hydraulic pilot control part includes a pilot valve body, a pilot valve core is provided in the pilot valve body, a handwheel is provided at the rear end of the pilot valve body and a vent hole is provided at the front end, and the handwheel is limited to the rear end of the pilot valve body by a pressure plate; the rear end of the pilot valve core is connected to the handwheel by a thread, and a limiting step is provided at the front end, and a limiting screw is provided on the pilot valve body at the corresponding position of the limiting step; a melting cavity is provided between the middle part of the pilot valve core and the pilot valve body, and sealing rings are provided on the pilot valve core on the front and rear sides of the melting cavity, respectively, and a control liquid hole and a control port are opened on the pilot valve body at the corresponding position of the melting cavity.

[0003] The existing pilot shut-off valve has a movable valve core made of soft polyoxymethylene material. This results in a soft seal between the valve core and the valve body, which has the disadvantage of poor resistance to ultra-high pressure. In addition, the soft material is prone to wear. After long-term use, the sealing performance of the pilot shut-off valve will decrease, affecting the sealing reliability of the pilot shut-off valve.

[0004] An improved pilot-operated shut-off valve is provided, particularly how to improve sealing reliability. Utility Model Content

[0005] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention provides a pilot-operated shut-off valve, the purpose of which is to improve sealing reliability.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a pilot shut-off valve, including a main valve body, a valve core, and a pilot valve assembly. The pilot valve assembly includes a pilot valve body disposed on the main valve body, a handwheel, and a movable valve stem disposed inside the pilot valve body and connected to the handwheel. A composite sealing mechanism is provided on the valve stem. The valve core is made of 3Cr13, and the sealing surface of the valve core is a conical surface.

[0007] The main valve body is made of 45 steel.

[0008] The composite sealing mechanism includes a first sealing element and a second sealing element, with the first sealing element located between the second sealing element and the valve stem.

[0009] The second sealing element includes a first contact surface that contacts the first sealing element, a second contact surface that contacts the inner circular surface of the pilot valve body, end faces located on both sides of the first and second contact surfaces, and two connecting surfaces coaxially arranged with the first contact surface. The two connecting surfaces are respectively connected to one end of the second contact surface and the edge of one end face. The diameter of the end face is smaller than the diameter of the second contact surface.

[0010] The first contact surface is provided with a positioning groove for accommodating the first sealing element. The positioning groove is an annular groove extending along the entire circumference on the first contact surface.

[0011] The positioning groove has an arc-shaped cross-section and is located at the middle position of the first contact surface.

[0012] The pilot shut-off valve of this utility model has a valve core made of 3Cr13 material, and a hard seal is formed between the main valve body and the valve core, which can improve the sealing performance and reliability of the pilot shut-off valve; at the same time, a composite sealing mechanism is set on the valve stem of the pilot valve assembly, which can improve the sealing performance and reliability of the pilot valve assembly. Attached Figure Description

[0013] This manual includes the following figures, which illustrate the following:

[0014] Figure 1 This is a cross-sectional view of the pilot shut-off valve of this utility model;

[0015] Figure 2 This is a cross-sectional view of the composite sealing mechanism;

[0016] Figure 3 This is a cross-sectional view of the second sealing element;

[0017] The following are marked in the diagram: 1. Main valve body; 2. Valve core; 3. Spring; 4. Pilot valve body; 5. Handwheel; 6. Valve stem; 7. Composite sealing mechanism; 8. Control port; 9. First sealing element; 10. Second sealing element; 11. First contact surface; 12. Second contact surface; 13. End face; 14. Connecting surface; 15. Positioning groove. Detailed Implementation

[0018] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solution of this utility model, and to facilitate its implementation.

[0019] like Figures 1 to 3As shown, this utility model provides a pilot shut-off valve, including a main valve body 1, a valve core 2 and a pilot valve assembly. The pilot valve assembly includes a pilot valve body 4 disposed on the main valve body 1, a handwheel 5 and a valve stem 6 movably disposed inside the pilot valve body 4 and connected to the handwheel 5. A composite sealing mechanism 7 is disposed on the valve stem 6.

[0020] Specifically, such as Figure 1 As shown, valve core 2 is movably disposed within the valve cavity of main valve body 1. A spring is clamped between valve core 2 and pilot valve body 4. One end of the spring is inserted into the inner cavity of valve core 2 from its open end. One end of valve core 2 is open, and the other end is closed. The closed end of valve core 2 has a sealing surface, which is a conical surface. The sealing surface is used to contact the main valve body 1 to achieve a seal. Valve core 2 is made of 3Cr13, a high-carbon chromium stainless steel with a chromium content of approximately 13%. It has good corrosion resistance, high strength, and wear resistance, which helps to improve the service life of the check valve. Main valve body 1 is made of 45# steel.

[0021] like Figure 1 As shown, the pilot valve body 4 is fixedly connected to one end of the main valve body 1 by bolts. The valve stem 6 is inserted into the inner cavity of the pilot valve body 4, and the valve stem 6 and the pilot valve body 4 are connected by threads. The handwheel 5 is fixedly connected to one end of the valve stem 6 and is located outside the pilot valve body 4. The handwheel 5 is used to drive the valve stem 6 to rotate around its axis. The pilot valve body 4 is provided with a control port 8 and a control fluid hole. The control port 8 is coaxially arranged with the valve cavity and valve core 2 of the main valve body 1. The control port 8 is used to connect the inner cavity of the pilot valve body 4 and the valve cavity of the main valve body 1. The control fluid hole is used to connect the inner cavity of the pilot valve body 4 and the pilot control fluid flow hole provided in the main valve body 1. The pilot control fluid flow hole is connected to the valve cavity. A circular groove extending along the entire circumference is provided on the outer surface of the valve stem 6. The composite sealing mechanism 7 is installed in the groove. When the valve stem 6 drives the composite sealing mechanism 7 to move along the circumference, and the composite sealing mechanism 7 moves between the control port 8 and the control fluid hole, the composite sealing mechanism 7 can prevent the flow of hydraulic oil between the control port 8 and the control fluid hole. The control port 8 and the control fluid hole are not connected, and hydraulic oil cannot enter the control port 8. The valve core 2 can move upward to the open state.

[0022] like Figures 1 to 3As shown, the composite sealing mechanism 7 includes a first sealing element 9 and a second sealing element 10, which are located in a groove. The first sealing element 9 is located between the second sealing element 10 and the valve stem 6. The second sealing element 10 includes a first contact surface 11 that contacts the first sealing element 9, a second contact surface 12 that contacts the inner circular surface of the pilot valve body 4, end faces 13 located on both sides of the first and second contact surfaces 11 and 12, and two connecting surfaces 14 coaxially arranged with the first contact surface 11. The two connecting surfaces 14 are respectively connected to one end of the second contact surface 12 and the edge of one end face 13. The diameter of the end face 13 is smaller than the diameter of the second contact surface 12. The first contact surface 11 and the second contact surface 12 are coaxial, and the end face 13 is a circular plane. The two end faces 13 are parallel and coaxial with the first contact surface 11, and each end face 13 is connected to one end of the first contact surface 11. The connecting surface 14 is located between the second contact surface 12 and an end face 13. The diameter of the end face 13 is smaller than the diameter of the second contact surface 12. The large-diameter end of the connecting surface 14 is connected to the second contact surface 12, and the small-diameter end of the connecting surface 14 is connected to the end face 13. When the composite sealing mechanism 7, which is fitted on the valve stem 6, moves with the valve stem 6 within the pilot valve body 4, the second contact surface 12 of the second sealing element 10 contacts the inner circular surface of the pilot valve body 4. When the second sealing element 10 moves with the valve stem 6 to the position of the control port 8 on the pilot valve body 4, both ends of the second sealing element 10 are conical, which avoids direct contact between the ends of the second sealing element 10 and the control port 8. This facilitates the second sealing element 10 to slide over the control port 8 on the pilot valve body 4 and reduces the contact area between the second sealing element 10 and the control port 8, thereby reducing the wear caused by the control port 8 on the second sealing element 10. This improves the sealing effect and service life of the composite sealing mechanism 7, and ultimately improves the sealing performance between the valve stem 6 and the pilot valve body 4.

[0023] like Figure 2 and Figure 3As shown, a positioning groove 15 for accommodating the first sealing element 9 is also provided on the first contact surface 11 of the second sealing element 10. The positioning groove 15 is an annular groove extending along the entire circumference on the first contact surface 11. The cross-sectional shape of the positioning groove 15 is arc-shaped to adapt to the shape of the first sealing element 9. The first sealing element 9 has a certain elasticity and is located inside the second sealing element 10. It can cause the second sealing element 10 to expand radially outward. Since the valve stem 6 is movable, when the pressurized liquid enters the inner cavity of the pilot valve body 4 through the control port 8, the valve stem 6 moves to align the control port 8 with the second sealing element 10. The pressurized liquid overflowing from the control port 8 will erode the second contact surface 12 of the second sealing element 10 and generate pressure on the second sealing element 10. This will cause the second sealing element 10 to tend to contract radially. The first sealing element 9, embedded in the positioning groove 15, applies a force to the second sealing element 10, which can keep the second sealing element 10 expanding outward. This makes the second sealing element 10 contact the inner surface of the pilot valve body 4 more tightly, reducing the erosion of the second sealing element 10 by the pressurized liquid overflowing from the control port 8 of the pilot valve body 4. This can further improve the sealing reliability and service life of the second sealing element 10 and further improve the sealing performance. Meanwhile, the tapered connecting surfaces 14 at both ends of the second sealing element 10 also have a certain guiding effect on the pressure liquid overflowing from the control port 8.

[0024] like Figure 2 and Figure 3 As shown, the positioning groove 15 is located at the middle position of the first contact surface 11 in the axial direction, and the second contact surface 12 also corresponds to the middle position of the first contact surface 11. The width of the positioning groove 15 in the axial direction is greater than the width of the second contact surface 12, thus ensuring that the positioning groove 15 can accommodate the first sealing element 9, which has a thickness greater than the second contact surface 12. Therefore, by placing the positioning groove 15 at the middle position of the first contact surface 11, the contact area between the first sealing element 9 and the second sealing element 10 is large, resulting in a strong force and further improving the sealing effect.

[0025] In this embodiment, the first sealing element 9 is an O-ring made of rubber and is fitted onto the valve stem 6. The first sealing element 9 has a certain degree of elasticity. The second sealing element 10 is made of nylon. Nylon sealing rings have the advantages of high strength, high precision, and good wear resistance, resulting in a long service life and good sealing effect.

[0026] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A pilot-operated shut-off valve, comprising a main valve body, a valve core, and a pilot valve assembly, characterized in that: The pilot valve assembly includes a pilot valve body mounted on the main valve body, a handwheel, and a movable valve stem located inside the pilot valve body and connected to the handwheel. A composite sealing mechanism is provided on the valve stem. The valve core is made of 3Cr13, and the sealing surface of the valve core is a conical surface.

2. The pilot shut-off valve according to claim 1, characterized in that: The main valve body is made of 45 steel.

3. The pilot shut-off valve according to claim 1, characterized in that: The composite sealing mechanism includes a first sealing element and a second sealing element, with the first sealing element located between the second sealing element and the valve stem.

4. The pilot shut-off valve according to claim 3, characterized in that: The second sealing element includes a first contact surface that contacts the first sealing element, a second contact surface that contacts the inner circular surface of the pilot valve body, end faces located on both sides of the first and second contact surfaces, and two connecting surfaces coaxially arranged with the first contact surface. The two connecting surfaces are respectively connected to one end of the second contact surface and the edge of one end face. The diameter of the end face is smaller than the diameter of the second contact surface.

5. The pilot shut-off valve according to claim 4, characterized in that: The first contact surface is provided with a positioning groove for accommodating the first sealing element. The positioning groove is an annular groove extending along the entire circumference on the first contact surface.

6. The pilot shut-off valve according to claim 5, characterized in that: The positioning groove has an arc-shaped cross-section and is located at the middle position of the first contact surface.

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