Axial flow pneumatic control valve

Abstract

The utility model discloses a kind of axial flow type pneumatic regulating valves, belong to fluid control valve technical field, comprising: valve body, top shell, pneumatic actuator, positioner and pneumatic actuator output rod;Its characterized in that, middle cavity and pressure chamber are equipped in the valve body, the middle cavity of the valve body is slidably connected with input shaft and valve shaft respectively, and over gear is rotatably connected, the valve body is also provided with flow guide cone, the balance chamber that is connected with middle cavity is equipped in the flow guide cone, the middle cavity is injected with lubricating grease to lubricate its internal parts;The outer wall of the valve body is provided with the pressure relief valve that is connected with middle cavity;The valve shaft both ends are provided with front shaft cover and rear shaft cover respectively, the valve shaft center is provided with balance hole, and its balance hole is connected with balance chamber and pressure chamber, the utility model is driven by gear rack and balance pressure relief structure, realizes valve core accurate control, flow regulation is sensitive and stable, sealing is reliable, lubrication is sufficient, maintenance is convenient, improve the safety and service life of pneumatic regulating valve.

Description

Technical Field

[0001] This utility model relates to the field of fluid control valve technology, specifically to an axial flow pneumatic regulating valve. Background Technology

[0002] A single-seat pneumatic control valve is an automated control device that adopts a straight-through single-seat structure and consists of components such as valve body, valve core, valve shaft, and actuator. Single-seat pneumatic control valves mostly adopt a linear push-pull mechanism between the valve stem and the valve core, resulting in a relatively simple transmission structure. Under large-diameter and high-pressure conditions, they are prone to problems such as high operating force, difficulty in accurately positioning the valve core, and decreased sealing performance. In addition, traditional single-seat pneumatic control valves are limited by the diameter and pressure rating, limiting their application scenarios. Furthermore, insufficient lubrication of internal transmission components and imbalance of the pressure chamber can easily cause wear or jamming of the valve shaft, shortening the valve's service life.

[0003] Based on this, this utility model designs an axial flow pneumatic regulating valve to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide an axial flow pneumatic regulating valve to solve the above-mentioned technical problems.

[0005] To achieve the above objectives, this utility model provides the following technical solution: an axial flow pneumatic regulating valve, comprising: a valve body, a top housing, a pneumatic actuator, a positioner, and a pneumatic actuator output rod; characterized in that the valve body is provided with a central cavity and a pressure cavity, an input shaft and a valve shaft are slidably connected in the central cavity of the valve body, and a transition gear is rotatably connected thereto; the valve body is also provided with a guide cone, and a balance cavity communicating with the central cavity is provided in the guide cone; lubricating grease is injected into the central cavity to lubricate its internal components; a pressure relief valve communicating with the central cavity is provided on the outer wall of the valve body; The valve shaft is provided with a front shaft cover and a rear shaft cover at both ends, and a balance hole is opened in the center of the valve shaft, which connects the balance chamber and the pressure chamber. The valve shaft is horizontally positioned, and the input shaft is vertically positioned and perpendicular to each other. Both the end of the input shaft and the outer wall of the valve shaft are provided with racks with hardened tooth surfaces. The transition gear meshes with the racks of the input shaft and the valve shaft, respectively.

[0006] Preferably, a valve core is fixedly installed at one end of the valve shaft near the rear shaft cover, and a sleeve is fixedly installed inside the valve body. A flow window is opened on the outer wall of the sleeve. The valve core and the sleeve are staggered and fit together. After relative sliding, the flow rate can be adjusted by changing the effective area of ​​the flow window on the sleeve wall.

[0007] Preferably, the middle cavity is a pressureless cavity. When the pressure in the middle cavity increases due to the plunger effect generated by the movement of the input shaft, the pressure relief valve automatically opens to release the pressure. The pressure relief valve is set to a pressure lower than the pipeline medium pressure to protect the valve shaft seal.

[0008] Preferably, the top of the valve body is fixedly connected to a top housing that communicates with the central cavity, and the pneumatic actuator is fixedly installed on the top of the top housing, with one end extending into the top housing and provided with a pneumatic actuator output rod.

[0009] Preferably, an upper bushing is fixedly connected between the top housing and the middle cavity of the valve body, one end of the input shaft passes through the upper bushing and extends into the top housing, and a coupling is fixedly connected between the end of the input shaft located in the top housing and the output rod of the pneumatic actuator.

[0010] Preferably, the positioner sensing end is hinged to the pneumatic actuator output rod. By inputting a control signal, the pneumatic actuator output rod is controlled to move up and down and stop at any position, thereby causing the valve core to stop at the target position and achieving precise flow control.

[0011] Preferably, a tail cap is detachably connected to the bottom of the valve body by bolts, and a sleeve fixing ring is detachably connected to one end of the valve body by bolts, with one end of the sleeve fixing ring abutting against one end of the sleeve.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows: Firstly, the unique design of the central cavity ensures long-term lubrication of the transmission components within the valve body during grease injection, preventing dry friction and jamming. Furthermore, the pressure relief valve ensures that the central cavity will not experience abnormal pressure rise due to the plunger effect or seal leakage, thus protecting the safety of the seals. Secondly, the valve shaft is connected to the pressure chamber and the balance chamber through the balance hole, and the forces at both ends of the valve shaft are balanced, which greatly reduces the operating force. The valve shaft drives the valve core to cooperate with the sleeve, and the flow rate is precisely adjusted by changing the flow window, which is suitable for large-diameter and high-pressure applications. Thirdly, the input shaft and the valve shaft are connected by a gear and rack with hardened tooth surface technology, which can greatly extend their service life and ensure good control of transmission accuracy during transmission, thus ensuring stable operation. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1This is a schematic diagram of the overall structure of this embodiment; Figure 2 This is a schematic diagram illustrating the valve shaft connection and fit in this embodiment; Figure 3 This embodiment highlights the input shaft connection and mating diagram. Figure 4 This is a schematic diagram highlighting the input shaft structure in this embodiment; Figure 5 This is a schematic diagram highlighting the valve shaft structure in this embodiment.

[0015] The attached diagram lists the components represented by each number as follows: 1. Guide cone; 2. Front axle cover; 3. Transition gear; 4. Tail cover; 5. Valve body; 6. Rear axle cover; 7. Valve shaft; 8. Valve core; 9. Sleeve; 10. Sleeve retaining ring; 11. Pressure relief valve; 12. Upper shaft sleeve; 13. Input shaft; 14. Coupling; 15. Positioner; 16. Pneumatic actuator output rod; 17. Pneumatic actuator; 18. Middle cavity; 19. Balance cavity; 20. Pressure cavity; 21. Top housing. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0017] Please see Figure 1-5 This utility model provides a technical solution: an axial flow pneumatic regulating valve, comprising: a valve body 5, a top housing 21, a pneumatic actuator 17, a positioner 15, and a pneumatic actuator output rod 16; characterized in that the valve body 5 has a central cavity 18 and a pressure cavity 20, an input shaft 13 and a valve shaft 7 are slidably connected in the central cavity 18 of the valve body 5, and an intermediate gear 3 is rotatably connected thereto; the valve body 5 also has a guide cone 1, and the guide cone 1 has a balance cavity 19 communicating with the central cavity 18, and lubricating grease is injected into the central cavity 18 to lubricate its internal components; a pressure relief valve 11 communicating with the central cavity 18 is provided on the outer wall of the valve body 5; The valve shaft 7 is provided with a front shaft cover 2 and a rear shaft cover 6 at both ends, and a balance hole is opened in the center of the valve shaft 7, which connects the balance chamber 19 and the pressure chamber 20. The valve shaft 7 is horizontally arranged, and the input shaft 13 is vertically arranged and perpendicular to each other. Both the end of the input shaft 13 and the outer wall of the valve shaft 7 are provided with racks with hardened tooth surfaces. The transition gear 3 meshes with the racks of the input shaft 13 and the valve shaft 7 respectively. The valve body 5 contains a central cavity 18 and a pressure chamber 20. An input shaft 13, a valve shaft 7, and a transition gear are arranged within the central cavity 18, forming a structure where the input shaft 13 is vertical, the valve shaft 7 is horizontal, and the two are driven by a rack and pinion and the transition gear. Driven by a pneumatic actuator 17, the input signal can be stably converted into the movement of the valve core 8. Simultaneously, a guide cone 1 and a balance chamber 19 are provided within the valve body 5, and lubricating grease is injected to ensure the long-term smooth operation of the parts within the central cavity 18. A pressure relief valve 11 is also arranged on the outer wall for pressure protection. This allows the pneumatic signal to be efficiently converted into the linear motion of the valve core 8, resulting in high transmission accuracy, low friction, and long service life. Furthermore, pressure protection and grease lubrication improve the stability and reliability of the valve.

[0018] In a further preferred embodiment, a valve core 8 is fixedly installed at one end of the valve shaft 7 after it approaches the shaft cover 6, and a sleeve 9 is fixedly installed inside the valve body 5. A flow window is opened on the outer wall of the sleeve 9. The valve core 8 and the sleeve 9 are staggered and fit together. They can slide relative to each other and the flow rate can be adjusted by changing the effective area of ​​the flow window on the wall of the sleeve 9. When the valve core 8 moves, it changes the effective area of ​​the flow window, thereby regulating the flow rate. The principle is similar to that of a spool valve, directly controlling the medium flow rate by changing the cross-sectional area of ​​the channel. It features a simple structure, sensitive response, and avoids the problem of insufficient precision in traditional valve on / off control, achieving high-precision linear flow regulation.

[0019] In a further preferred embodiment, the middle cavity 18 is a pressureless cavity. When the pressure in the middle cavity 18 increases due to the plunger effect generated by the movement of the input shaft 13, the pressure relief valve 11 automatically opens to release the pressure. The pressure relief valve 11 is set to a pressure lower than the pipeline medium pressure to protect the sealing ring of the valve shaft 7. The intermediate cavity 18 is designed as a pressureless chamber. During the reciprocating motion of the input shaft 13, the pressure in the intermediate cavity 18 will increase due to the plunger effect. At this time, the pressure relief valve 11 will automatically open to release the excess pressure. The pressure relief valve 11 is set to a pressure lower than the pipeline medium pressure, thereby ensuring that the valve shaft 7 sealing ring is not damaged by excessive pressure. Its principle is to achieve internal and external pressure difference balance through safe pressure relief, ensuring the stability of the valve's internal structure and the life of the sealing components, avoiding jamming, sealing failure or leakage caused by abnormal pressure, and improving the safety of the valve in long-term operation.

[0020] More preferably, the top of the valve body 5 is fixedly connected to the top housing 21 that communicates with the middle cavity 18, and the pneumatic actuator 17 is fixedly installed on the top of the top housing 21, with one end extending into the top housing 21 and provided with a pneumatic actuator output rod 16. The pneumatic actuator 17 can directly act on the input shaft 13 and drive the valve core 8 to move through the transmission mechanism, realizing the efficient conversion of external control signals into valve actions. This arrangement reduces intermediate transmission links, has a compact structure, faster action response, and ensures the execution accuracy of the control valve and the sensitivity of the pneumatic drive.

[0021] More preferably, an upper bushing 12 is fixedly connected between the top housing 21 and the middle cavity 18 of the valve body 5, one end of the input shaft 13 passes through the upper bushing 12 and extends into the top housing 21, and a coupling 14 is fixedly connected between the end of the input shaft 13 located in the top housing 21 and the pneumatic actuator output rod 16. The coupling 14 effectively compensates for installation errors, ensuring coaxial transmission between the input shaft 13 and the actuator output rod, thus preventing misalignment and wear. Its advantages include stable transmission, convenient maintenance, and a significant improvement in the force transmission efficiency of the pneumatic actuator 17.

[0022] In a further preferred embodiment, the sensing end of the positioner 15 is hinged to the output rod 16 of the pneumatic actuator. By inputting a control signal, the output rod 16 of the pneumatic actuator is controlled to move up and down and stop at any position, thereby causing the valve core 8 to stop at the target position and achieving precise flow control. The sensing end of the positioner 15 is hinged to the output rod 16 of the pneumatic actuator, enabling the sensing end of the positioner 15 to receive the up-and-down movement and stationary position of the output rod, thereby driving the valve core 8 to stop at the corresponding position and achieving precise control of the target flow rate. The principle lies in the positioner 15 being connected to the pneumatic actuator 17, converting the action signal into proportional pneumatic action of the actuator 17, ensuring that the action of the valve core 8 is highly consistent with the input signal. Its advantages include sensitive adjustment and high control accuracy, meeting the needs for continuous and precise flow rate adjustment under complex working conditions.

[0023] More preferably, the bottom of the valve body 5 is detachably connected to the tail cap 4 by bolts, and one end of the valve body 5 is detachably connected to the sleeve fixing ring 10 by bolts, with one end of the sleeve fixing ring 10 abutting against one end of the sleeve 9. A detachable tail cover 4 is provided at the bottom of the valve body 5, and an input shaft 13 with a moving space connected to the middle cavity 18 is provided to assist its movement operation. A detachable sleeve fixing ring 10 is provided at one end of the valve body 5. One end of the fixing ring presses the sleeve 9, realizing the stable installation of the sleeve 9 in the valve body 5. It can be easily replaced or repaired by bolt disassembly.

[0024] One specific application of this embodiment is: The valve body 5 is installed on the pipeline. The pneumatic actuator 17 and the positioner 15 are energized and ventilated. The middle cavity 18 is filled with grease, and the pressure relief valve 11 is in the closed state. The control system inputs the target opening signal to the positioner 15. The positioner 15 converts the electrical signal into the action control of the pneumatic actuator 17. Then, the pneumatic actuator 17 drives the pneumatic actuator output rod 16 to move up and down, and drives the input shaft 13 to make linear motion through the coupling 14. The rack at the end of the input shaft 13 drives the intermediate gear 3 to rotate. The intermediate gear 3 meshes with the rack on the valve shaft 7, thereby driving the valve shaft 7 to move horizontally. The movement of the valve shaft 7 causes the valve core 8 to slide relative to the sleeve 9. The position of the valve core 8 and the sleeve 9 in staggered contact changes, thereby changing the effective area of ​​the flow window on the wall of the sleeve 9. When the effective area of ​​the flow window increases, the flow rate increases; when the effective area decreases, the flow rate decreases. The valve core 8 can be stably stopped at any target position, achieving precise flow control. During operation, the balance hole in the center of valve shaft 7 connects pressure chamber 20 and balance chamber 19, ensuring force balance at both ends of valve shaft 7 and significantly reducing operating force. If the plunger effect of input shaft 13 causes the pressure in intermediate chamber 18 to rise, pressure relief valve 11 will automatically open to release the pressure in intermediate chamber 18 to a set safe range, avoiding damage to the seals. During continuous operation, the grease provides lubrication to the transition gear 3, input shaft 13, valve shaft 7 and rack in the intermediate cavity 18, extending service life and ensuring long-term operational stability.

[0025] In the description of this utility model, it should be understood that the terms "bottom", "one end", "top", "middle", "other end", "upper", "side", "top", "inner", "front", "center", "both ends", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0026] In this utility model, unless otherwise explicitly specified and limited, the terms "installation", "setting", "connection", "fixing", "screw connection", etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0027] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An axial flow pneumatic control valve, comprising: Valve body (5), top housing (21), pneumatic actuator (17), positioner (15) and pneumatic actuator output rod (16); characterized in that the valve body (5) is provided with a middle cavity (18) and a pressure cavity (20), the middle cavity (18) of the valve body (5) is slidably connected to an input shaft (13) and a valve shaft (7), and is rotatably connected to an intermediate gear (3), the valve body (5) is also provided with a guide cone (1), the guide cone (1) is provided with a balance cavity (19) communicating with the middle cavity (18), the middle cavity (18) is injected with lubricating grease to lubricate its internal components; the outer wall of the valve body (5) is provided with a pressure relief valve (11) communicating with the middle cavity (18). The valve shaft (7) is provided with a front shaft cover (2) and a rear shaft cover (6) at both ends respectively. The valve shaft (7) has a balance hole in the center, and the balance hole connects the balance chamber (19) and the pressure chamber (20). The valve shaft (7) is horizontally arranged, and the input shaft (13) is vertically arranged and perpendicular to each other. The end of the input shaft (13) and the outer wall of the valve shaft (7) are provided with racks with hard tooth surfaces. The transition gear (3) meshes with the racks of the input shaft (13) and the valve shaft (7) respectively.

2. The axial flow pneumatic regulating valve according to claim 1, characterized in that: A valve core (8) is fixedly installed at one end of the valve shaft (7) after it approaches the shaft cover (6). A sleeve (9) is fixedly installed inside the valve body (5). A flow window is opened on the outer wall of the sleeve (9). The valve core (8) and the sleeve (9) are staggered and fit together. They can slide relative to each other and the flow rate can be adjusted by changing the effective area of ​​the flow window on the sleeve (9) wall.

3. The axial flow pneumatic regulating valve according to claim 1, characterized in that: The middle cavity (18) is a pressureless cavity. When the pressure in the middle cavity (18) increases due to the plunger effect generated by the movement of the input shaft (13), the pressure relief valve (11) automatically opens to release the pressure. The pressure relief valve (11) is set to a pressure lower than the pipeline medium pressure to protect the sealing ring of the valve shaft (7).

4. The axial flow pneumatic regulating valve according to claim 1, characterized in that: The valve body (5) is fixedly connected to a top housing (21) that communicates with the middle cavity (18). The pneumatic actuator (17) is fixedly installed on the top of the top housing (21), and one end of it extends into the top housing (21) and is provided with a pneumatic actuator output rod (16).

5. An axial flow pneumatic regulating valve according to claim 4, characterized in that: An upper bushing (12) is fixedly connected between the top housing (21) and the middle cavity (18) of the valve body (5). One end of the input shaft (13) passes through the upper bushing (12) and extends into the top housing (21). A coupling (14) is fixedly connected between the end of the input shaft (13) located in the top housing (21) and the pneumatic actuator output rod (16).

6. An axial flow pneumatic regulating valve according to claim 5, characterized in that: The positioner (15) is hinged to the pneumatic actuator output rod (16) by inputting a control signal to control the pneumatic actuator output rod (16) to move up and down and stop at any position, so that the valve core (8) stops at the target position and achieves precise flow control.

7. An axial flow pneumatic regulating valve according to claim 2, characterized in that: The bottom of the valve body (5) is detachably connected to a tail cap (4) by bolts, and a sleeve fixing ring (10) is detachably connected to one end of the valve body (5) by bolts. One end of the sleeve fixing ring (10) is pressed against one end of the sleeve (9).

Images