Valve needle structure of ultrahigh-pressure stop valve capable of being automatically and coaxially adjusted

Abstract

An ultrahigh pressure stop valve needle structure capable of being adjusted coaxially comprises a steel ball, a sealing ring, a connecting shaft and a needle valve rod, the steel ball, the sealing ring, the connecting shaft and the needle valve rod are installed in an ultrahigh pressure stop valve, an ultrahigh pressure stop valve gas drive cylinder applies gas pressure in the range of about (0-0.5) MPa to drive the valve needle structure, and the valve needle structure and a valve seat are sealed through an extrusion deformation metal wire on a contact face. Reliable cut-off of ultrahigh pressure not smaller than 500 MPa is achieved. The connecting shaft and the needle valve rod are connected in an H6 / n5 interference fit mode. A steel ball with the hardness not smaller than 80 HRC and the diameter phi 2 is adopted for automatic aligning, and the contact area between the steel ball and a pneumatic piston of the stop valve is reduced, so that radial friction force is reduced, and coaxial adjustment of the part is achieved. Two O-shaped sealing rings with the diameter phi are assembled at the radial position of the connecting shaft, radial assembly of the assembly and a pneumatic piston in the stop valve is achieved, and the coaxiality adjusting margin is obtained by means of the compressible characteristic of the O-shaped sealing rings.

Description

Technical Field

[0001] The invention relates to a self-coaxially adjustable ultra-high pressure stop valve needle structure, which is used for ultra-high pressure pressure cut-off. Background Art

[0002] Automatic pressure stop valves are widely used in the automatic control of pressure control systems and pressure instruments in the fields of aviation, aerospace, and shipbuilding. Automatic pressure stop valves mainly include air-driven pressure stop valves and electromagnetic-driven pressure stop valves according to different driving modes. The pressure range is mainly concentrated in (0-60) MPa. According to the special needs of ultra-high pressure occasions, the maximum pressure can reach 250 MPa, and the internal density components of the stop valve mainly use metal end face wire seals to achieve the sealing and cut-off function through the extrusion deformation of the contact surface. Since ultra-high pressure stop valves above 250 MPa are rarely used, mature products have not yet been formed. Most of them are specially customized using the current ultra-high pressure stop valve metal end face wire seal method, and the sealing effect and service life of each product are uneven. Summary of the invention

[0003] The technical problem to be solved by the present invention is: to overcome the shortcomings of the prior art, solve the problems of poor sealing effect and low service life of ultra-high pressure stop valves of not less than 500MPa, meet the needs of automatic control of ultra-high pressure automatic metering equipment, and can be widely used in ultra-high pressure control systems in the fields of aviation, aerospace, etc., and automatic control links of ultra-high pressure instruments and equipment.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] A self-coaxially adjustable ultra-high pressure stop valve needle structure, comprising a steel ball, a sealing ring, a connecting shaft, and a needle valve stem;

[0006] The coupling is connected to the needle valve stem; a steel ball with a hardness of not less than 80HRC is used for automatic centering to reduce the contact area with the pneumatic piston of the ultra-high pressure stop valve; a sealing ring is installed at the radial position of the coupling.

[0007] In one embodiment of the present invention, the coupling shaft and the needle valve stem are connected by H6 / n5 interference fit.

[0008] In one embodiment of the present invention, the valve needle structure is coaxially adjusted by reducing the contact area with the pneumatic piston of the stop valve to reduce the radial friction force.

[0009] In one embodiment of the present invention, the compressible characteristic of the sealing ring is utilized to obtain the coaxiality adjustment margin.

[0010] A self-coaxially adjustable ultra-high pressure stop valve, comprising the above-mentioned valve needle structure, as well as a coaxial nut gland, a hydraulic cylinder, a cushion block, a combined sealing ring, a valve seat, a polytetrafluoroethylene gasket, an end coaxial nut, a first O-ring, a retaining ring, a screw, and a pneumatic piston;

[0011] The screw passes through the retaining ring and is connected to the pneumatic piston, thereby connecting the valve needle structure to the pneumatic piston;

[0012] The needle valve stem passes through the coaxial nut gland, hydraulic cylinder, gasket, and combined sealing ring, and contacts the valve seat. Under the push of the pneumatic piston, a metal hard seal is generated with the gasket to achieve pressure cutoff;

[0013] The combined sealing ring and the needle valve stem adopt radial sealing to achieve sealing;

[0014] After the coaxial nut gland is connected to the hydraulic cylinder, the gasket is pressed tightly, thereby fixing the combined sealing ring in the hydraulic cylinder;

[0015] The valve seat and the hydraulic cylinder are pressed tightly by connecting the end coaxial nut with the hydraulic cylinder;

[0016] A polytetrafluoroethylene gasket and a first O-type sealing ring are installed at the radial position of the valve seat.

[0017] In one embodiment of the present invention, the screws include a plurality of screws that are evenly distributed.

[0018] In one embodiment of the present invention, the coaxial nut gland 6 is connected to the hydraulic cylinder 7 by threads.

[0019] In one embodiment of the present invention, the end coaxial nut 11 is connected to the hydraulic cylinder 7 by threading.

[0020] In one embodiment of the present invention, the ultra-high pressure is not less than 500 MPa.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The present invention can effectively avoid the valve needle and the center hole of the hydraulic cylinder from being misaligned during the pressurization process, thereby preventing the valve needle from getting stuck or even breaking, by designing a self-coaxial adjustment design between the valve needle and the pneumatic piston.

[0023] (2) The present invention can effectively prevent the valve needle and the combined sealing ring from being subjected to uneven axial force, thereby preventing the sealing from failing and causing pressure leakage.

[0024] (3) The valve needle and valve seat can be accurately positioned when the stop valve is in the stop state, which reduces the damage of the valve needle to the metal sealing surface of the valve seat and improves the service life of the stop valve.

[0025] (4) After technical improvement, reliable sealing can be achieved under the ultra-high pressure cut-off of 500MPa, and the service life is greatly improved.

[0026] (5) The present invention is aimed at the special use requirements of ultra-high pressure stop valves above 500MPa, and provides an ultra-high pressure stop valve needle structure that can be self-coaxially adjusted, so as to overcome the problems of jamming and sealing failure caused by the misalignment between the valve needle and the dynamic seal and the valve needle guide structure when the valve needle of the traditional ultra-high pressure stop valve is fixedly connected.

[0027] (6) The present invention innovatively designs a valve needle self-coaxial adjustment structure to improve the sealing effect and service life of the ultra-high pressure stop valve.

[0028] (7) The present invention has high sealing reliability and operation sensitivity, which can meet the needs of automatic control of ultra-high pressure automatic metering equipment, and can be widely used in ultra-high pressure control systems in the fields of aviation, aerospace, etc., and automatic control links of ultra-high pressure instruments and equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is the valve needle structure of the present invention.

[0030] Figure numerals: 1- steel ball; 2- connecting shaft; 3, 4- sealing ring; 5- needle valve stem, 6- coaxial nut cover; 7- hydraulic cylinder; 8- gasket; 9- combined sealing ring; 10- valve seat; 13- polytetrafluoroethylene gasket; 11- end coaxial nut; 12- first O-ring; 14- retaining ring; 15- screw; 16- pneumatic piston. DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0032] A self-coaxially adjustable ultra-high pressure stop valve needle structure comprises a steel ball 1, a sealing ring (3, 4), a connecting shaft 2, and a needle valve stem 5. Figure 1 As shown, this component is installed inside the ultra-high pressure stop valve. Usually, the ultra-high pressure stop valve air drive cylinder applies a gas pressure in the range of about (0-0.5) MPa to drive the valve needle structure. The valve needle structure and the valve seat are sealed by the extruded deformed metal wire on the contact surface to achieve reliable shutoff of ultra-high pressure not less than 500 MPa.

[0033] The coupling shaft 2 and the needle valve stem 5 are connected by H6 / n5 interference fit.

[0034] A steel ball 1 with a diameter of φ2 and a hardness of not less than 80HRC is used for automatic centering, and the contact area with the pneumatic piston of the stop valve is reduced to reduce radial friction to coaxially adjust the component.

[0035] Two O-type sealing rings (3, 4) with a line diameter of φ are assembled at the radial position of the connecting shaft 2 to achieve radial assembly of the component and the pneumatic piston 16 in the stop valve, and the coaxiality adjustment margin is obtained by utilizing the compressible characteristics of the O-type sealing rings (3, 4).

[0036] A self-coaxially adjustable ultra-high pressure stop valve comprises a valve needle structure, a coaxial nut gland 6, a hydraulic cylinder 7, a cushion block 8, a combined sealing ring 9, a valve seat 10, a polytetrafluoroethylene gasket 13, an end coaxial nut 11, a first O-ring 12, a retaining ring 14, a screw 15, and a pneumatic piston 16.

[0037] Four screws 15 are evenly distributed through the retaining ring 14 and connected to the pneumatic piston 16, connecting the assembly formed by the needle valve stem 5, the connecting shaft 2, the steel ball 1 and the sealing ring (3, 4) to the pneumatic piston 16 to prevent the two from being separated when the gas piston 16 moves to the left.

[0038] The needle valve stem 5 passes through the coaxial nut gland 6, hydraulic cylinder 7, gasket 8, and combined sealing ring 9, and contacts the valve seat 10. Under the push of the pneumatic piston 16, a metal hard seal is generated with the gasket 8 to achieve pressure cutoff. At this time, the ultra-high pressure medium at the P inlet cannot flow out through the P outlet.

[0039] The combined sealing ring 9 and the needle valve stem 5 are sealed in a radial sealing manner.

[0040] The coaxial nut gland 6 and the hydraulic cylinder 7 are connected by threads to compress the gasket 8, thereby fixing the combined sealing ring 9 in the hydraulic cylinder 7.

[0041] The end coaxial nut 11 is connected with the hydraulic cylinder 7 by threads to press the valve seat 10 and the hydraulic cylinder 7 tightly.

[0042] A polytetrafluoroethylene gasket 13 and a first O-ring 12 are mounted at the radial position of the valve seat 10 .

[0043] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

[0044] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A self-coaxially adjustable ultra-high pressure stop valve needle structure, characterized in that: Including steel balls, sealing rings, couplings, and needle valve stems; The coupling is connected to the needle valve stem; a steel ball with a hardness of not less than 80HRC is used for automatic centering to reduce the contact area with the pneumatic piston of the ultra-high pressure stop valve; a sealing ring is installed at the radial position of the coupling.

2. The ultra-high pressure stop valve needle structure according to claim 1, characterized in that: The coupling shaft and the needle valve stem are connected by H6 / n5 interference fit.

3. The ultra-high pressure stop valve needle structure according to claim 1, characterized in that: The valve needle structure is coaxially adjusted by reducing the contact area with the pneumatic piston of the stop valve to reduce the radial friction force.

4. The ultra-high pressure stop valve needle structure according to claim 1, characterized in that: The compressible characteristic of the sealing ring is utilized to obtain the coaxiality adjustment margin.

5. A self-coaxially adjustable ultra-high pressure stop valve, characterized in that: It includes the valve needle structure as claimed in claim 1, as well as a coaxial nut gland, a hydraulic cylinder, a spacer, a combined sealing ring, a valve seat, a polytetrafluoroethylene gasket, an end coaxial nut, a first O-ring, a retaining ring, a screw, and a pneumatic piston; The screw passes through the retaining ring and is connected to the pneumatic piston, thereby connecting the valve needle structure to the pneumatic piston; The needle valve stem passes through the coaxial nut gland, hydraulic cylinder, gasket, and combined sealing ring, and contacts the valve seat. Under the push of the pneumatic piston, a metal hard seal is generated with the gasket to achieve pressure cutoff; The combined sealing ring and the needle valve stem adopt radial sealing to achieve sealing; After the coaxial nut gland is connected to the hydraulic cylinder, the gasket is pressed tightly, thereby fixing the combined sealing ring in the hydraulic cylinder; The valve seat and the hydraulic cylinder are pressed tightly by connecting the end coaxial nut with the hydraulic cylinder; A polytetrafluoroethylene gasket and a first O-type sealing ring are installed at the radial position of the valve seat.

6. The ultra-high pressure stop valve according to claim 5, characterized in that: The screws include a plurality of screws which are evenly distributed.

7. The ultra-high pressure stop valve according to claim 5, characterized in that: The coaxial nut gland 6 is connected to the hydraulic cylinder 7 by threads.

8. The ultra-high pressure stop valve according to claim 5, characterized in that: The end coaxial nut 11 is connected to the hydraulic cylinder 7 by threading.

9. The ultra-high pressure stop valve according to claim 5, characterized in that: The ultra-high pressure shall not be less than 500MPa.

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