Pneumatic control valve

Abstract

The utility model discloses a pneumatic control valve which comprises a valve body, a valve seat, a throttling sleeve, a valve cover, a valve rod, an auxiliary filler chamber, a main filler chamber and a pneumatic actuator, and the main filler chamber and the auxiliary filler chamber are arranged between the valve cover and the valve rod. Auxiliary filler and an auxiliary spring are arranged in the auxiliary filler chamber; the pneumatic actuator is arranged above the valve cover and is connected with the top of the valve rod; the number of effective sealing rings of the whole packing can be increased; after being compressed, the auxiliary spring continuously applies thrust to the auxiliary filler to compensate the main filler loosening and failure caused by the loss of the main filler in the original main filler chamber; the two positions of the valve rod are supported and guided through the combination of the auxiliary valve rod filler and the main filler, the diameter of the valve rod is reduced, bending deformation of the valve rod is avoided, friction force between the filler and the valve rod is effectively reduced, sealing of the valve rod can be better met, and media are prevented from leaking out; the adjusting precision of the valve is improved, and the adjusting characteristic of the valve is optimized.

Description

Technical Field

[0001] The utility model belongs to the technical field of valves, and in particular relates to a pneumatic regulating valve. Background Art

[0002] A regulating valve, also known as a control valve, is an actuator in an automatic control system. Unlike common shut-off valves, it regulates the flow and pressure of fluids within a system to meet the fluid parameter requirements of different application scenarios. Regulating valves are typically driven by electric or pneumatic actuators. Because pneumatic actuators use air as their working medium, they offer advantages such as simple structure, high safety, and strong overload resistance. They are particularly suitable for applications requiring explosion-proofing. Therefore, pneumatic actuators are widely used in regulating valve applications.

[0003] Due to the compressibility of air in existing pneumatic control valves, particularly when using large diaphragm pneumatic actuators, it takes time for air to fill and exhaust the air chamber, resulting in a slow response speed. Furthermore, to prevent leakage, the valve stem of existing pneumatic control valves must withstand significant packing clamping force. When the control valve receives a control signal to change the valve opening, the valve stem must be driven by the pneumatic actuator from a stationary state to a moving state, causing the valve stem to frequently switch between these two states. Mechanically, the friction between the valve stem and the packing frequently switches between static friction and sliding friction. Because static friction between the valve stem and the packing is always greater than sliding friction, when the valve stem overcomes the static packing friction and transitions from a stationary state to a moving state, the packing friction on the valve stem transforms into sliding friction, instantly reducing resistance and causing the valve stem to jump. This displacement deviation of the valve stem directly affects the control accuracy of the control valve.

[0004] It can be seen that in order to meet the adjustment accuracy requirements during operation, the existing pneumatic control valve has frequent opening and closing movements with small amplitudes. In order to overcome the jump phenomenon caused by the difference between the sliding friction and the static friction between the valve stem and the packing, it is hoped that the valve stem diameter is as small as possible. However, a too small valve stem diameter, that is, a slender stem, will bend during the valve closing process, affecting the valve stem sealing and other performances. Utility Model Content

[0005] In response to at least one of the aforementioned deficiencies of existing pneumatic control valves, the present invention provides a pneumatic control valve that addresses the problem that, in order to meet the requirements for control accuracy during operation, existing pneumatic control valves frequently open and close with minimal amplitude. To overcome the jump caused by the difference between the sliding friction and the static friction between the valve stem and the packing, it is desirable to have a valve stem diameter as small as possible. However, an excessively small valve stem diameter, i.e., a slender stem, can bend during valve closing, affecting performance such as the stem seal. The present invention facilitates reducing the valve stem diameter and preventing stem bending and deformation, thereby effectively reducing packing friction, ensuring valve stem sealing, improving valve control accuracy, and optimizing valve control characteristics.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] The utility model provides a pneumatic regulating valve, comprising a valve body, a valve seat, a throttling sleeve, a valve cover, a valve stem, an auxiliary stuffing chamber, a main stuffing chamber and a pneumatic actuator, wherein a cavity is arranged inside the valve body; the valve seat is installed inside the valve body; the throttling sleeve is arranged in the valve body and is arranged above the valve seat; the valve cover is installed on the top of the valve body, and a through-hole is provided on the valve cover; the lower end of the valve stem passes through the through-hole and the throttling sleeve and extends into the valve seat; the auxiliary stuffing chamber is arranged between the bottom of the valve cover and the valve stem; the interior of the auxiliary stuffing chamber is sequentially provided with an auxiliary stuffing pressure cover, auxiliary stuffing, an auxiliary stuffing pad and an auxiliary spring; the main stuffing chamber is arranged between the valve cover and the valve stem above the auxiliary stuffing chamber; the main stuffing chamber is arranged in the main stuffing chamber; the pneumatic actuator is arranged above the valve cover and connected to the top of the valve stem.

[0008] Preferably, a first annular groove is provided on the inner wall of the bottom of the perforation, and the auxiliary filling chamber is formed between the first groove and the outer wall of the valve stem.

[0009] Preferably, an outer wall of the valve stem is provided with an annular second groove at the bottom position of the valve cover, and the auxiliary filling chamber is formed between the second groove and the inner wall of the perforation.

[0010] Preferably, the auxiliary stuffing gland, the auxiliary stuffing, the auxiliary stuffing pad and the auxiliary spring are in contact with each other in sequence from bottom to top.

[0011] Preferably, the bottom outer wall of the auxiliary packing gland is provided with an annular raised step, and the step is provided below the valve cover.

[0012] Preferably, the top surface of the step contacts the top surface of the valve cover.

[0013] Preferably, an external thread is provided on the top of the auxiliary stuffing gland, an internal thread is provided at the bottom of the through hole, and the auxiliary stuffing gland is screwed into the bottom of the through hole.

[0014] Preferably, the auxiliary stuffing pad is configured in a ring shape and is sleeved on the outside of the valve stem.

[0015] Preferably, the main stuffing chamber is arranged between the top of the valve cover and the valve stem; the main stuffing pad, the main stuffing, the main stuffing sleeve and the stuffing pressure plate are arranged in sequence from bottom to top inside the main stuffing chamber.

[0016] Preferably, a second annular groove is provided on the top inner wall of the through hole, and the main filling chamber is formed between the second groove and the outer wall of the valve stem.

[0017] Preferably, a first metal wound gasket is arranged between the bottom of the valve seat and the valve body, and a second metal wound gasket is arranged between the top of the throttle sleeve and the valve body; the pneumatic actuator is connected to the top of the valve stem through a connecting block; an external thread is arranged on the top of the valve cover, and a nut is arranged above the bottom of the pneumatic actuator, and the nut is screwed to the top of the valve cover.

[0018] The pneumatic regulating valve of the utility model has the following beneficial effects:

[0019] 1. The pneumatic control valve of the present invention is improved on the basis of the existing technology. An auxiliary stuffing chamber is provided at the bottom of the valve cover, and an auxiliary spring, an auxiliary stuffing pad, an auxiliary stuffing and an auxiliary stuffing cover are sequentially placed in the auxiliary stuffing chamber to form a group of auxiliary valve stem stuffing, thereby increasing the number of effective sealing rings of the overall stuffing; after the auxiliary spring is compressed, it continuously applies thrust to the auxiliary stuffing, thereby compensating for the loosening and failure of the main stuffing caused by the loss of the main stuffing in the original main stuffing chamber; the auxiliary valve stem stuffing is combined with the main stuffing to provide support and guidance for the two positions of the valve stem, so that the valve stem can be lifted and lowered more smoothly, which is conducive to reducing the diameter of the valve stem and avoiding bending and deformation of the valve stem, and reducing the diameter of the valve stem is conducive to effectively reducing the friction between the stuffing and the valve stem; it can avoid the valve stem diameter being too small, that is, the slender valve stem will bend during the valve closing process; and the auxiliary stuffing is combined with the main stuffing to better meet the sealing of the valve stem and prevent the medium from leaking out; it is conducive to improving the adjustment accuracy of the valve and optimizing the adjustment characteristics of the valve.

[0020] 2. In the pneumatic control valve of the present invention, the bottom of the auxiliary packing gland can be arranged outside the bottom of the valve cover to form a structure for the auxiliary packing to block the leakage of the medium, which can reduce the load of the main packing on the top of the valve cover, thereby reducing the number of turns and the pressing force of the top main packing, and can reduce the clamping force of the main packing on the valve stem, thereby reducing the static friction and sliding friction between the valve stem and the main packing, and at the same time, it also reduces the difference between the static friction and sliding friction between the valve stem and the main packing, reducing the requirement for the output thrust of the pneumatic actuator, so that the jump phenomenon of the valve stem is significantly improved, and it can be more adaptable to frequent switching actions, which is beneficial to effectively improve the response speed and adjustment accuracy of the control valve while ensuring the performance of the pneumatic actuator remains unchanged, and optimize the adjustment characteristics of the control valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0022] Figure 1 This is a structural schematic diagram of a pneumatic control valve provided in one embodiment of the present utility model.

[0023] Figure 2 for Figure 1 A partial enlarged view of point A in the middle.

[0024] In the figure, 1 is the valve body, 2 is the first metal wound gasket, 201 is the auxiliary packing cover, 202 is the auxiliary packing, 203 is the auxiliary packing gasket, 204 is the auxiliary spring, 3 is the valve seat, 4 is the throttling sleeve, 5 is the valve stem, 6 is the valve cover, 7 is the main packing gasket, 8 is the main packing, 9 is the main packing sleeve, 10 is the main packing pressure plate, 11 is the pneumatic actuator, 12 is the connecting block, 13 is the nut, and 14 is the second metal wound gasket. DETAILED DESCRIPTION

[0025] To make the purpose, technical solutions, and advantages of the present invention more clear, the following will provide a clear and complete description of the technical solutions of the present invention in conjunction with specific embodiments of the present invention and the corresponding drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0026] The technical solutions provided by various embodiments of the present invention are described in detail below with reference to the accompanying drawings. Example

[0027] Please refer to Figure 1 and Figure 2, a pneumatic regulating valve comprises a valve body 1, a valve seat 3, a throttling sleeve 4, a valve cover 6, a valve stem 5, an auxiliary stuffing chamber, a main stuffing chamber and a pneumatic actuator 11. A cavity is arranged inside the valve body 1; the valve seat 3 is installed inside the valve body 1; the throttling sleeve 4 is arranged in the valve body 1 and is arranged above the valve seat 3; the valve cover 6 is installed on the top of the valve body 1, and a through hole is opened on the valve cover 6; the lower end of the valve stem 5 passes through the through hole and the throttling sleeve 4 and extends into the valve seat 3; the auxiliary stuffing chamber is arranged between the bottom of the valve cover 6 and the valve stem 5; the interior of the auxiliary stuffing chamber is sequentially provided with an auxiliary stuffing gland 201, an auxiliary stuffing 202, an auxiliary stuffing pad 203 and an auxiliary spring 204 from bottom to top; the main stuffing chamber is arranged between the valve cover 6 and the valve stem 5 above the auxiliary stuffing chamber; the main stuffing chamber is arranged between the valve cover 6 and the valve stem 5 above the auxiliary stuffing chamber; the main stuffing 8 is arranged in the main stuffing chamber; the pneumatic actuator 11 is arranged above the valve cover 6 and connected to the top of the valve stem 5.

[0028] The pneumatic control valve of this embodiment is improved on the basis of the existing technology. An auxiliary stuffing chamber is provided at the bottom of the valve cover 6, and an auxiliary spring 204, an auxiliary stuffing pad 203, an auxiliary stuffing 202 and an auxiliary stuffing gland 201 are sequentially placed in the auxiliary stuffing chamber to form a group of auxiliary valve stem stuffing; after the auxiliary spring 204 is compressed, it continuously applies thrust to the auxiliary stuffing 202, thereby compensating for the relaxation and failure of the main stuffing 8 caused by the loss of the main stuffing 8 in the original main stuffing chamber; the auxiliary valve stem stuffing provides support and guidance for the valve stem 5, so that the valve stem 5 can be raised and lowered more smoothly, which is beneficial to reducing the diameter of the valve stem 5 and avoiding bending and deformation of the valve stem 5, and is beneficial to effectively reducing the friction of the main stuffing 8; it can meet the sealing of the valve stem 5, increase the number of effective sealing rings of the overall stuffing, and is beneficial to improving the adjustment accuracy of the valve and optimizing the adjustment characteristics of the valve.

[0029] The auxiliary spring 204 may be configured as a helical compression spring.

[0030] Specifically, the auxiliary stuffing gland 201 , the auxiliary stuffing 202 , the auxiliary stuffing pad 203 and the auxiliary spring 204 are in contact with each other in sequence from bottom to top.

[0031] In some embodiments, a first annular groove is provided on the inner wall of the bottom of the perforation, forming an auxiliary packing chamber between the first groove and the outer wall of the valve stem 5. Specifically, by increasing the inner diameter of the bottom of the perforation, an auxiliary packing chamber is formed between the first groove and the outer wall of the valve stem 5. This prevents the valve stem 5 from being too small in diameter, which would cause the slender valve stem 5 to bend during valve closing. Furthermore, the sealing of the valve stem 5 is ensured. By adding a set of auxiliary valve stem packing, the number of effective sealing rings of the packing is increased, further reducing the friction of the valve stem 5 and preventing the valve stem 5 from bending, thereby improving the valve adjustment accuracy and optimizing the valve adjustment characteristics.

[0032] In some embodiments, the bottom outer wall of the auxiliary packing gland 201 is provided with an annular raised step, and the step is provided below the valve cover 6 .

[0033] Specifically, the top surface of the step contacts the top surface of the valve cover 6 .

[0034] The top of the auxiliary stuffing gland 201 is provided with an external thread, and the bottom position of the through hole is provided with an internal thread, and the auxiliary stuffing gland 201 is screwed into the bottom of the through hole.

[0035] Specifically, the auxiliary packing pad 203 is configured to be annular and sleeved on the outside of the valve stem 5 .

[0036] like Figure 1 As shown, specifically, the main stuffing chamber is arranged between the top of the valve cover 6 and the valve stem 5; the main stuffing pad 7, the main stuffing 8, the main stuffing sleeve 9 and the stuffing pressure plate 10 are arranged in sequence from bottom to top inside the main stuffing chamber.

[0037] An annular second groove is provided on the top inner wall of the perforation, and a main filling chamber is formed between the second groove and the outer wall of the valve stem 5 .

[0038] The main packing pad 7, the main packing 8, the main packing pressing sleeve 9 and the packing pressing plate 10 are in contact with each other from bottom to top.

[0039] Please refer to Figure 1 and Figure 2 A first metal wound gasket 2 is arranged between the bottom of the valve seat 3 and the valve body 1, and a second metal wound gasket 14 is arranged between the top of the throttle sleeve 4 and the valve body 1; the pneumatic actuator 11 is connected to the top of the valve stem 5 through a connecting block 12; an external thread is arranged on the top of the valve cover 6, and a nut 13 is arranged above the bottom of the pneumatic actuator 11, and the nut is screwed to the top of the valve cover 6.

[0040] The valve stem 5 is configured as a round rod, and the cross sections of the auxiliary stuffing gland 201 , auxiliary stuffing 202 , auxiliary stuffing pad 203 and auxiliary spring 204 as well as the main stuffing pad 7 , main stuffing 8 , main stuffing sleeve 9 and stuffing pressure plate 10 are all configured as circular rings sleeved on the valve stem 5 .

[0041] The pneumatic actuator 11 and the top of the valve stem 5 are connected to the connecting block 12 through bolts respectively.

[0042] The above are merely embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A pneumatic regulating valve, characterized in that: include: a valve body, wherein a cavity is provided inside the valve body; a valve seat, mounted inside the valve body; A throttle sleeve is arranged in the valve body and above the valve seat; A valve cover is mounted on the top of the valve body, and a perforation is provided on the valve cover; a valve stem, the lower end of which passes through the through hole and the throttle sleeve and extends into the valve seat; An auxiliary stuffing chamber is provided between the bottom of the valve cover and the valve stem; an auxiliary stuffing gland, auxiliary stuffing, an auxiliary stuffing pad and an auxiliary spring are provided in the auxiliary stuffing chamber from bottom to top; A main stuffing chamber is provided between the valve cover and the valve stem above the auxiliary stuffing chamber; main stuffing is provided in the main stuffing chamber; The pneumatic actuator is arranged above the valve cover and connected to the top of the valve stem.

2. The pneumatic regulating valve according to claim 1, characterized in that: An annular first groove is provided on the bottom inner wall of the through hole, and the auxiliary filling chamber is formed between the first groove and the outer wall of the valve stem.

3. The pneumatic regulating valve according to claim 1, characterized in that: The auxiliary stuffing gland, the auxiliary stuffing, the auxiliary stuffing pad and the auxiliary spring are in contact with each other in sequence from bottom to top.

4. The pneumatic regulating valve according to claim 1, characterized in that: The bottom outer wall of the auxiliary packing gland is provided with an annular raised step, and the step is provided below the valve cover.

5. The pneumatic regulating valve according to claim 4, characterized in that: A top surface of the step contacts a top surface of the valve cover.

6. The pneumatic regulating valve according to claim 4, characterized in that: The top of the auxiliary stuffing gland is provided with an external thread, the bottom position of the through hole is provided with an internal thread, and the auxiliary stuffing gland is screwed into the bottom of the through hole.

7. The pneumatic regulating valve according to claim 1, characterized in that: The auxiliary stuffing pad is arranged in a ring shape and is sleeved on the outside of the valve stem.

8. The pneumatic control valve according to any one of claims 1 to 7, characterized in that: The main stuffing chamber is arranged between the top of the valve cover and the valve stem; the main stuffing pad, the main stuffing, the main stuffing sleeve and the stuffing pressure plate are arranged in sequence from bottom to top in the main stuffing chamber.

9. The pneumatic regulating valve according to claim 8, characterized in that: A second annular groove is provided on the top inner wall of the through hole, and the main filling chamber is formed between the second groove and the outer wall of the valve stem.

10. The pneumatic regulating valve according to claim 8, characterized in that: A first metal wound gasket is arranged between the bottom of the valve seat and the valve body, and a second metal wound gasket is arranged between the top of the throttle sleeve and the valve body; the pneumatic actuator is connected to the top of the valve stem through a connecting block; an external thread is arranged on the top of the valve cover, and a nut is arranged above the bottom of the pneumatic actuator, and the nut is screwed to the top of the valve cover.

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