Pneumatic needle type regulating valve

Abstract

The utility model belongs to the field of valves, and particularly relates to a pneumatic needle type regulating valve which comprises a valve body, a valve cover, a pneumatic actuating mechanism and a valve core assembly, the valve core assembly comprises a valve rod and a valve core, a valve seat is arranged in the valve body, a valve cage is arranged on the valve seat, the valve core is in linkage fit with the valve rod, and the valve core penetrates through the valve cage and extends into the valve seat. The lower end of the valve element is provided with a cambered surface contact part matched with the valve seat, and the valve seat is provided with a convex ring part making contact with the cambered surface contact part. The valve element is designed to be of a needle type structure, the valve element makes contact with the convex ring part of the valve seat through the cambered surface contact part, the contact area of the valve element and the valve seat can be effectively reduced, flow resistance can be effectively reduced, and the sensitivity and stability of micro flow control are improved; as the contact area is small, the flow sectional area can be obviously changed by slight movement of the valve core, and the valve is suitable for accurate control of extremely small flow.

Description

Technical Field

[0001] This utility model belongs to the field of valve technology, specifically relating to a pneumatic needle valve. Background Technology

[0002] A pneumatic control valve is an industrial automation control instrument whose core function is to precisely adjust process parameters such as flow rate, pressure, temperature, or liquid level of the medium in a pipeline by receiving signals from the control system. Its power source is compressed air, and the actuator (such as a cylinder or diaphragm) converts the air pressure into mechanical thrust, driving the valve core to move and change the valve opening, thereby achieving flow control.

[0003] The existing pneumatic control valve has a large contact area between the valve core and the valve seat, resulting in a large flow resistance. This leads to low sensitivity of the pneumatic control valve to small flow control and unreliable performance. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings and deficiencies of the existing technology and to provide a pneumatic needle valve that can effectively reduce flow resistance and improve the sensitivity and stability of micro-flow control.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A pneumatic needle regulating valve includes a valve body, a valve cover disposed on the valve body, a pneumatic actuator and a valve core assembly disposed on the valve cover, the valve core assembly including a valve stem and a valve core that are linked and cooperate with the pneumatic actuator, a valve seat disposed in the valve body, a valve cage disposed on the valve seat, the valve core and the valve stem being linked and cooperated, the valve core passing through the valve cage and extending into the valve seat, the lower end of the valve core having an arc-shaped contact portion that cooperates with the valve seat, and the valve seat having a convex ring portion that contacts the arc-shaped contact portion.

[0006] In some embodiments, a sealing assembly is provided between the valve core and the valve seat. The sealing assembly includes a sealing ring and a clamping ring for pressing the sealing ring. The valve seat is provided with a positioning groove for placing the sealing ring. The sealing ring is disposed in the positioning groove and forms a sealing fit between the sealing ring and the valve seat and the valve core.

[0007] In some embodiments, the clamping ring is threadedly connected to the valve seat, and the clamping ring presses the sealing ring into the positioning groove.

[0008] In some embodiments, the lower end of the valve stem has a connecting portion extending into the valve cage, the connecting portion having a frustum portion that mates with the valve seat, the valve seat having a stepped portion that mates with the frustum portion, and the stepped portion having a limiting inclined surface that contacts the frustum portion.

[0009] In some embodiments, the connecting portion is provided with a threaded hole, and the upper end of the valve core has a screw portion, which is connected to the threaded hole.

[0010] In some embodiments, the upper end of the valve stem extends outside the valve cover and is connected to the pneumatic actuator. A packing assembly is provided between the valve cover and the valve stem. The packing assembly includes a packing gland and packing threaded onto the valve cover. The packing is disposed between the valve cover, the valve stem, and the packing gland.

[0011] In some embodiments, the valve cover is threadedly connected to the valve body, and a sealing gasket is provided between the valve cover and the valve body.

[0012] In some embodiments, the valve cover is provided with a positioning groove that cooperates with the valve cage, and the upper end of the valve cage is engaged in the positioning groove, thus forming a limiting fit between the valve cage and the valve cover.

[0013] In some embodiments, the valve body is provided with an air inlet and an air outlet, the valve body is provided with an air inlet channel connecting the valve cavity and the air inlet, and the valve body is provided with an air outlet channel connecting the valve cavity and the air outlet.

[0014] In some embodiments, the outer peripheral wall of the valve cage is provided with a plurality of air holes that communicate with the exhaust channel.

[0015] The beneficial effects of this invention are as follows: The valve core adopts a needle-type structure design, and the valve core contacts the convex ring of the valve seat through the arc-shaped contact part, which can effectively reduce the contact area between the valve core and the valve seat, thereby effectively reducing flow resistance and improving the sensitivity and stability of micro-flow control. Due to the small contact area, even a small movement of the valve core can significantly change the flow cross-sectional area, making it suitable for precise control of extremely small flow rates. Furthermore, under the same pneumatic actuator thrust, the smaller the contact area, the greater the sealing pressure (specific pressure) per unit area, resulting in a tighter seal and effectively reducing leakage. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of this utility model.

[0017] Figure 1 This is a structural diagram of an embodiment of the present utility model;

[0018] Figure 2 for Figure 1 Enlarged view of section A. Detailed Implementation

[0019] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0021] The directional and positional terms used in this utility model, such as up, down, front, back, left, right, inside, outside, top, bottom, side, etc., are only for reference to the accompanying drawings. Therefore, the directional and positional terms used are for the purpose of explaining and understanding this utility model, and not for limiting the scope of protection of this utility model.

[0022] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments:

[0023] like Figure 1 As shown, a pneumatic needle control valve includes a valve body 1, a valve cover 2 mounted on the valve body 1, a pneumatic actuator 3 mounted on the valve cover 2, and a valve core assembly 4. The valve core assembly 4 includes a valve stem 41 and a valve core 42 that are linked and cooperate with the pneumatic actuator 3. A valve seat 11 is disposed inside the valve body 1, and a valve cage 12 is disposed on the valve seat 11. The valve core 42 is linked and cooperates with the valve stem 41, passing through the valve cage 12 and extending into the valve seat 11. The lower end of the valve core 42 has an arc-shaped contact portion 421 that cooperates with the valve seat 11. The valve seat 11 has a convex ring portion 111 that contacts the arc-shaped contact portion 421. The valve core adopts a needle-type structure design. The valve core contacts the convex ring portion of the valve seat through the arc-shaped contact portion, which can effectively reduce the contact area between the valve core and the valve seat, effectively reduce flow resistance, and improve the sensitivity and stability of micro-flow control. Due to the small contact area, a small movement of the valve core can significantly change the flow cross-sectional area, making it suitable for precise control of extremely small flow rates. Furthermore, under the same pneumatic actuator thrust, the smaller the contact area, the greater the sealing pressure (specific pressure) per unit area, resulting in a tighter seal and effectively reducing leakage.

[0024] like Figure 2As shown, a sealing assembly 5 is provided between the valve core 42 and the valve seat 11. The sealing assembly 5 includes a sealing ring 51 and a clamping ring 52 for pressing the sealing ring 51. A positioning groove 112 for placing the sealing ring 51 is provided inside the valve seat 11. The sealing ring 51 is positioned in the positioning groove 112, forming a sealing fit between the sealing ring 51 and the valve seat 11 and the valve core 42. The clamping ring 52 is threadedly connected to the valve seat 11, and the clamping ring 52 presses the sealing ring 51 tightly within the positioning groove. The sealing assembly improves the sealing performance between the valve core and the valve seat, and the threaded connection between the clamping ring and the valve seat facilitates the assembly of the sealing assembly and the valve seat, resulting in higher assembly efficiency. The lower end of the valve stem 41 has a connecting portion 411 extending into the valve cage 12. The connecting portion 411 has a frustum portion 412 that mates with the valve seat 11. The valve seat 11 has a stepped portion 113 that mates with the frustum portion 412. A limiting inclined surface 114 that contacts the frustum portion 412 is provided on the stepped portion 113. The limiting inclined surface on the valve seat, which mates with the valve stem, ensures reliable valve stem movement within the valve body. The connecting portion 411 has a threaded hole 413, and the upper end of the valve core 42 has a screw portion 422 connected to the threaded hole 413. The valve core and valve stem are assembled using a threaded connection, facilitating assembly and improving assembly efficiency.

[0025] like Figure 1 As shown, the upper end of the valve stem 41 extends outside the valve cover 2 and is connected to the pneumatic actuator 3. A packing assembly 6 is provided between the valve cover 2 and the valve stem 41. The packing assembly 6 includes a packing gland 61 and packing 62 threadedly connected to the valve cover 2. The packing 62 is disposed between the valve cover 2, the valve stem 41, and the packing gland 61. The packing assembly fills the space between the valve cover and the valve stem, thereby enhancing the sealing performance between the valve cover and the valve stem. The valve cover 2 is threadedly connected to the valve body 1, and a sealing gasket 7 is provided between the valve cover 2 and the valve body 1. The valve cover and valve body are assembled using a threaded connection, which makes assembly more convenient, and the sealing gasket enhances the sealing performance between the valve cover and the valve body.

[0026] like Figure 1 and 2As shown, the valve cover 2 has a positioning groove 21 that mates with the valve cage 12. The upper end of the valve cage 12 is engaged in the positioning groove 21, forming a limiting fit between the valve cage 12 and the valve cover 2. The valve cage and the valve cover are connected by a snap-fit ​​mechanism, which facilitates the assembly of the valve cage and the valve cover and improves assembly efficiency. The valve body 1 is provided with an air inlet 101 and an air outlet 102. An air inlet channel 103 is provided inside the valve body 1, connecting the valve cavity 100 and the air inlet 101. An air outlet channel 104 is provided inside the valve body 1, connecting the valve cavity 100 and the air outlet 102. Multiple air holes 121 are provided on the outer peripheral wall of the valve cage 12, which are connected to the air outlet channel 104. With multiple air holes on the valve cage, some fluid enters the rear cavity of the valve core through the small holes on the valve cage, balancing the pressure before and after the valve core. This also reduces the thrust required by the pneumatic actuator, making the valve adjustment more sensitive and stable.

[0027] The above description is only one embodiment of the present utility model and is not intended to limit the scope of protection of the present utility model; the scope of protection of the present utility model is defined by the claims in the claims, and all equivalent changes and modifications made in accordance with the utility model are within the scope of protection of the present utility model patent.

Claims

1. A pneumatic needle valve, comprising a valve body, a valve cover disposed on the valve body, and a pneumatic actuator and valve core assembly disposed on the valve cover, characterized in that: The valve core assembly includes a valve stem and a valve core that are linked and cooperate with a pneumatic actuator. A valve seat is provided in the valve body, and a valve cage is provided on the valve seat. The valve core is linked and cooperates with the valve stem. The valve core passes through the valve cage and extends into the valve seat. The lower end of the valve core has an arc-shaped contact portion that cooperates with the valve seat. The valve seat has a convex ring portion that contacts the arc-shaped contact portion.

2. The pneumatic needle valve according to claim 1, characterized in that: A sealing assembly is provided between the valve core and the valve seat. The sealing assembly includes a sealing ring and a clamping ring for pressing the sealing ring. A positioning groove for placing the sealing ring is provided in the valve seat. The sealing ring is placed in the positioning groove and forms a sealing fit between the sealing ring and the valve seat and the valve core.

3. The pneumatic needle valve according to claim 2, characterized in that: The clamping ring is threadedly connected to the valve seat, and the clamping ring presses the sealing ring into the positioning groove.

4. The pneumatic needle valve according to claim 1 or 2, characterized in that: The lower end of the valve stem has a connecting portion extending into the valve cage. The connecting portion is provided with a frustum portion that mates with the valve seat. The valve seat has a stepped portion that mates with the frustum portion. The stepped portion is provided with a limiting inclined surface that contacts the frustum portion.

5. The pneumatic needle valve according to claim 4, characterized in that: The connecting part is provided with a threaded hole, and the upper end of the valve core has a screw part, which is connected to the threaded hole.

6. The pneumatic needle valve according to claim 1, characterized in that: The upper end of the valve stem extends outside the valve cover and is connected to the pneumatic actuator. A packing assembly is provided between the valve cover and the valve stem. The packing assembly includes a packing gland and packing threaded onto the valve cover. The packing is disposed between the valve cover, the valve stem, and the packing gland.

7. The pneumatic needle valve according to claim 1, characterized in that: The valve cover is threaded to the valve body, and a sealing gasket is provided between the valve cover and the valve body.

8. The pneumatic needle valve according to claim 1, characterized in that: The valve cover is provided with a positioning groove that cooperates with the valve cage. The upper end of the valve cage is engaged in the positioning groove, thus forming a limiting fit between the valve cage and the valve cover.

9. The pneumatic needle valve according to claim 1, characterized in that: The valve body is provided with an air inlet and an air outlet, and the valve body is provided with an air inlet channel connecting the valve cavity and the air inlet, and an air outlet channel connecting the valve cavity and the air outlet.

10. The pneumatic needle valve according to claim 9, characterized in that: The valve cage has multiple air holes on its outer peripheral wall that are connected to the exhaust channel.

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