A pneumatic differential pressure common rail drive actuator and a force analysis method for its actuator posture

Abstract

A pneumatic differential pressure common rail actuator comprises a pneumatic actuator, a pneumatic valve, and a pneumatic control unit. The pneumatic valve comprises a valve body and a rotor valve core. The rotor valve core is inserted radially into the valve body along the direction of extension of the gas pipeline. The rotor valve core rotates circumferentially and is axially and radially limited within the valve body. The upper portion of the rotor valve core slides upward and downward and is coaxially inserted into the valve stem. An arc-shaped guide groove is formed on the circumferential outer wall of the upper portion of the rotor valve core. An air hole is radially formed in the middle portion of the rotor valve core. The bottom of the rotor valve core is rotatably connected to the bottom inner wall of the valve body via a valve core bearing. This pneumatic differential pressure common rail actuator and its actuation posture force analysis method have the advantage of scientific computability. The basic theory of mechanical analysis of the pneumatic differential pressure common rail actuator is established, and the relevant formulas derived based on this basic theory are highly instructive for the design, verification, and testing of the structure of the present invention.

Description

Technical Field

[0001] The present invention relates to the technical field of gas valves, and in particular to a pneumatic differential pressure common rail drive actuator and a force analysis method for its actuator posture. Background Art

[0002] Existing gas pressure regulators, regulating valves and other products usually use a straight rod drive structure to drive the actuator, which drives the valve stem through pneumatic, electric and other drives to control the valve core opening. However, this is still a linear drive method, resulting in a complex valve core and valve seat structure for existing pressure regulators and regulating valves, such as Figure 1 and Figure 2 The two most representative classic structures of pressure regulators in the existing technology, namely the meandering flow type and the axial flow type, both use pneumatic drivers to drive the valve stem in a linear stroke.

[0003] Disadvantages of the existing linear travel drive structure:

[0004] 1. Structural complexity caused by motion trajectory: Linear actuation, whether driving the valve core or the valve port, requires a moving unit and a cooperating fixed unit. To meet the linear motion requirements of the moving unit and the flow path, the valve seat structure inevitably becomes complex. Consequently, the complex valve seat and valve body structures of existing pressure regulators and control valves make manufacturing difficult, resulting in a scarcity of high-quality products and limiting product development in the industry.

[0005] 2. Uncertainty of linear stroke: The linear stroke structure cannot uniformly set the valve core stroke of pressure regulators and control valves of different sizes. For example, the valve core strokes of DN50 and DN100 pressure regulators and control valves are different. Different drive structures need to be designed for products of different sizes, and the versatility is very poor.

[0006] 3. Functional Limitations: The linear travel structure has significant limitations on product functionality. Because its linear motion is sliding, when the force balance of the force actuator changes, the sliding direction and state cannot be determined, and the motion state cannot be clearly calculated. Therefore, the product cannot obtain further positioning control functions. As a result, the functions of the pressure regulator and control valve are relatively simple. Summary of the Invention

[0007] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a pneumatic differential pressure common rail drive actuator and a force analysis method for its execution posture. The structure of the pneumatic differential pressure common rail drive actuator has the advantage of scientific computability, and a basic theory of mechanical analysis of the pneumatic differential pressure common rail drive actuator is established. The relevant formulas derived under this basic theory are of great guiding significance for the design, verification, and testing of the structure of the present invention.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] A pneumatic differential pressure common rail drive actuator comprises a pneumatic actuator, a pneumatic valve and a pneumatic control unit. The pneumatic valve is fixedly mounted on a gas pipeline. The pneumatic valve is adjusted and connected to the pneumatic actuator. The signal gas collection end of the pneumatic control unit is respectively connected to the gas pipeline at the inlet and exhaust ends of the pneumatic valve. The control gas output end of the pneumatic control unit is connected to the pneumatic actuator to provide control power for the pneumatic actuator to open and close the pneumatic valve.

[0010] The pneumatic valve includes a valve body and a rotor valve core, wherein the rotor valve core is radially movably inserted into the interior of the valve body along the extension direction of the gas pipeline; the rotor valve core rotates circumferentially and is connected to the interior of the valve body with axial and radial limit connections, the upper part of the rotor valve core rises and falls and slides and is coaxially inserted into the valve stem, an arc guide groove is provided on the circumferential outer wall of the upper part of the rotor valve core, an air hole is radially provided in the middle part of the rotor valve core, and the bottom of the rotor valve core is rotatably connected to the bottom inner wall of the valve body through a valve core bearing.

[0011] Moreover, the pneumatic actuator includes a shell, a valve stem, a drive diaphragm and a drive spring, wherein the shell is fixed above the pneumatic valve, the top of the inner wall of the shell is fixedly connected to the drive spring, the middle part of the inner wall of the shell is sealed and fixed with the drive diaphragm, and the bottom of the shell rises and falls, slides and penetrates the connected valve stem; the top of the valve stem is fixedly connected to the drive diaphragm, the lower part of the valve stem extends into the interior of the pneumatic valve, and the bottom of the valve stem is radially formed with a valve stem rotor connected to the inner wall of the arc guide groove for sliding guidance; one end of the drive spring is pressed and supported on the top inner wall of the shell, and the other end of the drive spring is pressed and supported on the top surface of the drive diaphragm, and the drive spring and the valve stem are coaxially arranged.

[0012] Moreover, the air control unit includes a controller, a P1 signal tube, a P2 signal tube and a P3 signal tube, wherein the controller is respectively connected to the exhaust ends of the P1 signal tube and the P2 signal tube, and the air inlet end of the P3 signal tube; the air inlet end of the P1 signal tube is connected to the air inlet end gas pipeline of the pneumatic valve; the air inlet end of the P2 signal tube is connected to the air exhaust end gas pipeline of the pneumatic valve, and the exhaust end of the P2 signal tube is also connected to the inside of the shell of the pneumatic actuator located above the driving diaphragm; the exhaust end of the P3 signal tube is connected to the inside of the shell of the pneumatic actuator located below the driving diaphragm.

[0013] Moreover, the arc-shaped guide groove is radially opened on the outer wall of the rotor valve core, the groove top of the arc-shaped guide groove is open, the groove bottom of the arc-shaped guide groove is a blind groove, and the central angle between the groove top and the groove bottom of the arc-shaped guide groove is 90°.

[0014] A method for analyzing the force of a pneumatic differential pressure common rail drive actuator in its execution posture comprises the following steps:

[0015] Step 1: Define F as the force acting on the valve stem rotor in the direction of gravity; define f1 and f2 as the force components of F, i.e., the directional force exerted by the valve stem rotor on the inner wall of the arc guide groove; define θ as the angle between f2 and F; define α as the angle of valve core rotation, which is measured in radians when calculating torque work, and is expressed in radα; define h as the displacement of the diaphragm required to drive the valve core to reach a certain rotation angle; define fa as the force component of f1 in the tangential direction, fa = f1cosθ; define r as the radius of the valve core; and we can obtain:

[0016] f1=F×sinθ;…………………………………………………………………………(1)

[0017] Step 2: Since f2 is the friction force, according to the friction force formula: f = μ × N, where μ is the friction factor and N is the normal pressure, according to the track force analysis, the normal pressure of the friction force is the component of F in the normal direction of the track curve, so we can get:

[0018] f2=μ×F×sinθ;………………………………………………………………(2)

[0019] Step 3: According to the torque formula: T = F × r × cosθ, we can get:

[0020] The torque component f1 is: T1=f1×r×cosθ…………………………………………………………(3)

[0021] The torque component f2 is: T2=f2×r×cos(90°-θ)…………………………………………(4)

[0022] Among them, the angle between the f2 component and the valve core rotation direction is (90°-θ);

[0023] Step 4: Since F is the resultant force of f1 and f2, according to the law of conservation of energy, the work done by F should be equal to the work done by the two component forces. According to the work calculation formula: W = F × s × cosθ, where F is the force, s is the displacement, and θ is the angle between the force and the direction of motion, we can get: The work done by the resultant force is: W F =F×h, (there is no angle between the direction of the resultant force and the direction of valve stem movement), according to the rotational work calculation formula: W=T×radα, where T is the torque and radα is the angular displacement (radians) generated by the torque;

[0024] The work done by the force component f1 is: W f1 =T1×radα, substituting into formula (3), we can get:

[0025] W f1 =f1×r×cosθ×radα, substituting into formula (1), we can get:

[0026] W f1 =F×sinθ×r×cosθ×radα

[0027] W f1 =F×r×radα×sinθcosθ………………………………………………………………(5)

[0028] The work done by the force component f2 is: W f2 =T2×radα, substituting into formula (4), we can get:

[0029] W f2 =f2×r×cos(90°-θ)×radα, substituting into formula (2), we can obtain:

[0030] W f2 =μ×F×sinθ×r×cos(90°-θ)×radα

[0031] W f2 =μ×F×r×radα×sinθ×cos(90°-θ)…………………………………………(6)

[0032] Step 5: According to the law of conservation of energy, we can get: W F =W f1 +|W f2 |, since the work done by f2 is loss, its absolute value should be taken when calculating the total work done; substituting it into equations (5) and (6), we get:

[0033] F×h=F×r×radα×sinθcosθ+|μ×F×r×radα×sinθ×cos(90°-θ)|

[0034] Further calculation of the formula yields:

[0035] h=r×radα×sinθcosθ+|μ×r×radα×sinθcos(90°-θ)|

[0036] h=r×radα×(sinθcosθ+|μsinθcos(90°-θ)|)

[0037] According to the sine-cosine conversion formula:

[0038] in: The arc is exactly 90°, so we can get cos(90°-θ)=-sinθ………………………(7)

[0039] Substituting into formula (7), we can get:

[0040] h=r×radα×(sinθcosθ+|-μsinθsinθ|)

[0041] h=r×radα×(sinθcosθ+μsinθsinθ)…………………………………………(8)

[0042] Step 6: According to the auxiliary angle formula of trigonometric function, we can deduce:

[0043]

[0044] Where μ is the metal friction coefficient, which is 0.25. Substituting it into formula (9) further evolves:

[0045]

[0046] Step 7: According to equations (1) and (3), the minimum spool torque is:

[0047] T1=f1×r×cosθ

[0048] T=F×r×sinθcosθ

[0049] According to the trigonometric formula: We can get:

[0050] Substituting into formula (10) we can get:

[0051]

[0052] Where: F=|F KX -F P3 |

[0053] F KX The loading force of the spring in the pneumatic actuator can be calculated based on the spring coefficient and compression amount;

[0054] F P3 The loading force of the P3 air pressure on the driving diaphragm can be calculated based on the P3 imported air pressure value and the force-bearing area of ​​the driving diaphragm;

[0055] Therefore, according to formula (11), the minimum torque value required by the valve core at any rotation angle can be calculated.

[0056] The advantages and technical effects of the present invention are:

[0057] 1. The pneumatic differential pressure common rail drive actuator of the present invention has a rotor valve core with a rotor structure. The entire process from opening to closing is a 90° angular stroke. Regardless of the size of the product, it can be uniformly set to a 90° angular stroke, which is more uniform and controllable than existing products.

[0058] 2. This pneumatic differential pressure common rail actuator features an arc-shaped guide groove around the circumference of the rotor valve core. This converts the linear force of the valve stem into rotational force during actuation, eliminating the need for a complex valve seat and body structure to accommodate the valve core's motion. This design is simpler than existing valve seat structures and facilitates fabrication.

[0059] 3. The force analysis method of the pneumatic differential pressure common rail drive actuator in the present invention in its execution posture derives a mechanical formula specific to the structure based on the track transmission characteristics of the arc guide groove, making the special structure of the present invention scientifically calculable and establishing a unique basic mechanical theory.

[0060] 4. The force analysis method of a pneumatic differential pressure common rail drive actuator in its execution posture of the present invention has a basic mechanical theory that is the core technology of the present invention and is an innovation not possessed by existing pressure regulators and control valves. The relevant formulas derived based on this basic theory are highly instructive for the design, verification, and testing of the structure of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is an actuator of a meander-type linear travel drive structure in the prior art;

[0062] Figure 2 It is an actuator of an axial flow linear travel drive structure in the prior art;

[0063] Figure 3 A schematic diagram of the working principle of the pneumatic differential pressure common rail drive actuator of the present invention;

[0064] Figure 4 Schematic diagram of force analysis of the execution posture of the pneumatic differential pressure common rail drive actuator of the present invention (front view and cross-sectional view);

[0065] Figure 5 Schematic diagram (main view and cross-sectional view) of force comparison analysis of the pneumatic differential pressure common rail drive actuator of the present invention at multiple different execution positions;

[0066] In the figure: 1-housing; 2-valve body; 3-rotor valve core; 4-controller; 5-drive spring; 6-drive diaphragm; 7-valve stem; 8-valve stem rotor; 9-arc guide groove; 10-valve core bearing; a-P1 signal tube; b-P2 signal tube; c-P3 signal tube. DETAILED DESCRIPTION

[0067] In order to further understand the content, features and effects of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings. It should be noted that the present embodiments are illustrative and not restrictive, and the scope of protection of the present invention cannot be limited thereby.

[0068] A pneumatic differential pressure common rail drive actuator comprises a pneumatic actuator, a pneumatic valve and a pneumatic control unit. The pneumatic valve is fixedly mounted on a gas pipeline. The pneumatic valve is adjusted and connected to the pneumatic actuator. The signal gas collection end of the pneumatic control unit is respectively connected to the gas pipeline at the inlet and exhaust ends of the pneumatic valve. The control gas output end of the pneumatic control unit is connected to the pneumatic actuator to provide control power for the pneumatic actuator to open and close the pneumatic valve.

[0069] The pneumatic valve includes a valve body 2 and a rotor valve core 3, wherein the rotor valve core is radially movably inserted into the interior of the valve body along the extension direction of the gas pipeline; the rotor valve core rotates circumferentially and is connected to the interior of the valve body with axial and radial limit connections, the upper part of the rotor valve core rises and falls and slides and is coaxially inserted into the valve stem 7, an arc-shaped guide groove 9 is provided on the circumferential outer wall of the upper part of the rotor valve core, an air hole is radially provided in the middle part of the rotor valve core, and the bottom of the rotor valve core is rotatably connected to the bottom inner wall of the valve body through a valve core bearing 10.

[0070] Moreover, the pneumatic actuator includes a shell 1, a valve stem, a drive diaphragm 6 and a drive spring 5, wherein the shell is fixed above the pneumatic valve, the top of the inner wall of the shell is fixedly connected to the drive spring, the middle part of the inner wall of the shell is sealed and fixed with the drive diaphragm, and the bottom of the shell rises and falls, slides and penetrates the valve stem; the top of the valve stem is fixedly connected to the drive diaphragm, the lower part of the valve stem extends into the interior of the pneumatic valve, and the bottom of the valve stem is radially formed with a valve stem rotor 8 that is connected to the inner wall of the arc guide groove for sliding guidance; one end of the drive spring is pressed and supported on the inner wall of the top surface of the shell, and the other end of the drive spring is pressed and supported on the top surface of the drive diaphragm, and the drive spring and the valve stem are coaxially arranged.

[0071] Moreover, the air control unit includes a controller 4, a P1 signal tube a, a P2 signal tube b and a P3 signal tube c, wherein the controller is respectively connected to the exhaust ends of the P1 signal tube and the P2 signal tube, and the air inlet end of the P3 signal tube; the air inlet end of the P1 signal tube is connected to the air inlet end gas pipeline of the pneumatic valve; the air inlet end of the P2 signal tube is connected to the air exhaust end gas pipeline of the pneumatic valve, and the exhaust end of the P2 signal tube is also connected to the inside of the shell of the pneumatic actuator located above the driving diaphragm; the exhaust end of the P3 signal tube is connected to the inside of the shell of the pneumatic actuator located below the driving diaphragm.

[0072] Moreover, the arc-shaped guide groove is radially opened on the outer wall of the rotor valve core, the groove top of the arc-shaped guide groove is open, the groove bottom of the arc-shaped guide groove is a blind groove, and the central angle between the groove top and the groove bottom of the arc-shaped guide groove is 90°.

[0073] A method for analyzing the force of a pneumatic differential pressure common rail drive actuator in its execution posture comprises the following steps:

[0074] Step 1: Define F as the force acting on the valve stem rotor in the direction of gravity; define f1 and f2 as the force components of F, i.e., the directional force exerted by the valve stem rotor on the inner wall of the arc guide groove; define θ as the angle between f2 and F; define α as the angle of valve core rotation, which is measured in radians when calculating torque work, and is expressed in radα; define h as the displacement of the diaphragm required to drive the valve core to reach a certain rotation angle; define fa as the force component of f1 in the tangential direction, fa = f1cosθ; define r as the radius of the valve core; and we can obtain:

[0075] f1=F×sinθ;…………………………………………………………………………(1)

[0076] Step 2: Since f2 is the friction force, according to the friction force formula: f = μ × N, where μ is the friction factor and N is the normal pressure, according to the track force analysis, the normal pressure of the friction force is the component of F in the normal direction of the track curve, so we can get:

[0077] f2=μ×F×sinθ;………………………………………………………………(2)

[0078] Step 3: According to the torque formula: T = F × r × cosθ, we can get:

[0079] The torque component f1 is: T1=f1×r×cosθ…………………………………………………………(3)

[0080] The torque component f2 is: T2=f2×r×cos(90°-θ)…………………………………………(4)

[0081] Among them, the angle between the f2 component and the valve core rotation direction is (90°-θ);

[0082] Step 4: Since F is the resultant force of f1 and f2, according to the law of conservation of energy, the work done by F should be equal to the work done by the two component forces. According to the work calculation formula: W = F × s × cosθ, where F is the force, s is the displacement, and θ is the angle between the force and the direction of motion, we can get: The work done by the resultant force is: W F =F×h, (there is no angle between the direction of the resultant force and the direction of valve stem movement), according to the rotational work calculation formula: W=T×radα, where T is the torque and radα is the angular displacement (radians) generated by the torque;

[0083] The work done by the force component f1 is: W f1 =T1×radα, substituting into formula (3), we can get:

[0084] W f1 =f1×r×cosθ×radα, substituting into formula (1), we can get:

[0085] W f1 =F×sinθ×r×cosθ×radα

[0086] W f1 =F×r×radα×sinθcosθ………………………………………………………………(5)

[0087] The work done by the force component f2 is: W f2 =T2×radα, substituting into formula (4), we can get:

[0088] W f2 =f2×r×cos(90°-θ)×radα, substituting into formula (2), we can obtain:

[0089] W f2 =μ×F×sinθ×r×cos(90°-θ)×radα

[0090] W f2 =μ×F×r×radα×sinθ×cos(90°-θ)…………………………………………(6)

[0091] Step 5: According to the law of conservation of energy, we can get: W F =W f1 +|W f2 |, since the work done by f2 is loss, its absolute value should be taken when calculating the total work done; substituting it into equations (5) and (6), we get:

[0092] F×h=F×r×radα×sinθcosθ+|μ×F×r×radα×sinθ×cos(90°-θ)|

[0093] Further calculation of the formula yields:

[0094] h=r×radα×sinθcosθ+|μ×r×radα×sinθcos(90°-θ)|

[0095] h=r×radα×(sinθcosθ+|μsinθcos(90°-θ)|)

[0096] According to the sine-cosine conversion formula:

[0097] in: The arc is exactly 90°, so we can get cos(90°-θ)=-sinθ………………………(7)

[0098] Substituting into formula (7), we can get:

[0099] h=r×radα×(sinθcosθ+|-μsinθsinθ|)

[0100] h=r×radα×(sinθcosθ+μsinθsinθ)…………………………………………(8)

[0101] Step 6: According to the auxiliary angle formula of trigonometric function, we can deduce:

[0102]

[0103] Where μ is the metal friction coefficient, which is 0.25. Substituting it into formula (9) further evolves:

[0104]

[0105] Step 7: According to equations (1) and (3), the minimum spool torque is:

[0106] T1=f1×r×cosθ

[0107] T=F×r×sinθcosθ

[0108] According to the trigonometric formula: We can get:

[0109] Substituting into formula (10) we can get:

[0110]

[0111] Where: F=|F KX -F P3 |

[0112] F KX The loading force of the spring in the pneumatic actuator can be calculated based on the spring coefficient and compression amount;

[0113] F P3 The loading force of the P3 air pressure on the driving diaphragm can be calculated based on the P3 imported air pressure value and the force-bearing area of ​​the driving diaphragm;

[0114] Therefore, according to formula (11), the minimum torque value required by the valve core at any rotation angle can be calculated.

[0115] In addition, the present invention preferably adopts mature products and mature technical means in the existing technology for the air hole structure of the rotor valve core, the position of the air hole and the air path connection and disconnection relationship between the air hole and the inner wall of the valve body.

[0116] In addition, it is preferred in the present invention that the controller adopts a mature product in the existing technology.

[0117] The working principle of the present invention is described as follows:

[0118] Figure 3 The pneumatic actuator and the pilot constitute the drive unit of the present invention. The high-pressure air pressure before the valve is introduced into the pilot through the P1 signal tube as the driving air source, and the air pressure after the valve is introduced into the pilot through the P2 signal tube as the detection air source. The pilot compares the value of P2 with its set parameter and outputs a stable driving air pressure P3 based on the comparison result. The pressure is introduced into the lower cavity of the driving diaphragm in the pneumatic actuator through the P3 signal tube.

[0119] The driving air pressure P3 is compared with the air pressure obtained by acting on the driving diaphragm and the driving spring to obtain a differential pressure. When the differential pressure direction is upward, the driving diaphragm will move upward, and when the differential pressure direction is downward, the driving diaphragm will move downward.

[0120] The rotor valve core is a circumferential body with a central air hole that matches the valve body. Its outer circumference is radially cut with an arc-shaped guide groove for transmission. The differential pressure drives the diaphragm movement, which is transmitted to the valve core through the valve stem and the stem rotor. The stem rotor transmits the driving force to the arc-shaped guide groove. When the driving force on the valve stem is downward, the arc-shaped guide groove receives a counterclockwise rotational force, driving the rotor valve core counterclockwise. As the rotor valve core rotates a certain angle, the central air hole gradually rotates away from the valve seat sealing surface and connects to the valve body flow path, gradually opening the valve. When the driving force on the valve stem is upward, the arc-shaped guide groove receives a clockwise rotational force, driving the rotor valve core clockwise. As the rotor valve core rotates a certain angle, the central air hole gradually rotates and approaches the valve seat sealing surface, gradually reducing the area of ​​communication with the valve body flow path, and gradually closing the valve.

[0121] Figure 4 As shown in the figure, the spring force Fkx on the upper side of the driving diaphragm in the pneumatic actuator is downward, and the P3 air pressure loading force FP3 is upward. These two forces act on the driving diaphragm to generate a differential pressure thrust F. After the differential pressure thrust F is transmitted to the arc guide groove through the valve stem and valve stem rotor, it is converted into two components: f1 and f2. Among them, the f1 component is the external force of the rotor valve core rotation, and the f2 component is the dynamic friction reaction force. θ is the angle between the tangent direction of the track curve and F. Under the action of the differential pressure thrust F, the actuator and the valve core have the following Figure 5 The three states described.

[0122] Finally, it should be noted that formula (10) is the core formula of the present invention, and its key innovation lies in:

[0123] 1) Computability of track curves:

[0124] This formula, after designing the rotor spool radius and the drive diaphragm stroke, calculates the included angle θ of each point in the arc-shaped guide groove based on the entire range of the rotor spool rotation angle α from 90° to 0, and then plots the complete trajectory using a computer. The trajectory calculated using Equation 10 maintains a synchronized motion trajectory with the rotor spool's rotation, ensuring the accuracy of the present invention's conversion of the pneumatic drive unit's linear stroke into the rotor spool's angular stroke.

[0125] 2) Versatility of pneumatic drive units

[0126] According to formula (10), the curve angle θ and the rotor valve core rotation angle α are necessarily related factors, and the driving diaphragm stroke h can be a constant value, which means that the same pneumatic actuator can theoretically be applied to rotor valve cores of different r sizes.

[0127] This key conclusion proves that the arc-shaped guide groove track drive structure of the present invention solves the problem of inconsistent sizes and lack of universality between the drive actuator and the rotor valve core in the prior art.

[0128] Finally, it is preferred that the present invention adopts mature products and mature technical means in the prior art for all the parts not described in the present invention.

[0129] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A pneumatic differential pressure common rail drive actuator, characterized by: It includes a pneumatic actuator, a pneumatic valve and a pneumatic control unit. The pneumatic valve is fixed on the gas pipeline. The pneumatic valve is adjusted and connected to the pneumatic actuator. The signal gas collection end of the pneumatic control unit is respectively connected to the gas pipeline at the air inlet end and the gas pipeline at the exhaust end of the pneumatic valve. The control gas output end of the pneumatic control unit is connected to the pneumatic actuator to provide control power for the pneumatic actuator to open and close the pneumatic valve. The pneumatic valve comprises a valve body and a rotor valve core, wherein the rotor valve core is inserted into the interior of the valve body in a radially movable manner along the extension direction of the gas pipeline; the rotor valve core rotates circumferentially and is connected to the interior of the valve body in an axial and radially limited manner; the upper portion of the rotor valve core rises and slides and is coaxially inserted into the valve stem; an arc-shaped guide groove is formed on the circumferential outer wall of the upper portion of the rotor valve core, an air hole is radially formed in the middle portion of the rotor valve core, and the bottom of the rotor valve core is rotatably connected to the bottom inner wall of the valve body via a valve core bearing; The drive diaphragm movement generated by the differential pressure is transmitted to the valve core through the valve stem and the valve stem rotor, and the valve stem rotor transmits the driving force to the arc guide groove; When the driving force at the valve stem is downward, the arc-shaped guide groove will obtain counterclockwise rotation force and drive the rotor valve core to rotate counterclockwise. As the rotor valve core rotates, the central air hole will gradually rotate and leave the valve seat sealing surface and communicate with the valve body flow channel, causing the valve to gradually open; When the driving force of the valve stem is upward, the arc guide groove will obtain a clockwise rotation force and drive the rotor valve core to rotate clockwise. As the rotor valve core rotates a certain angle, its central air hole will gradually rotate and approach the valve seat sealing surface while gradually reducing the communicating area with the valve body flow channel, causing the valve to gradually close.

2. The pneumatic differential pressure common rail drive actuator according to claim 1, characterized in that: The pneumatic actuator includes a shell, a valve stem, a drive diaphragm and a drive spring, wherein the shell is fixed above the pneumatic valve, the top of the inner wall of the shell is fixedly connected to the drive spring, the middle part of the inner wall of the shell is sealed and fixed with the drive diaphragm, and the bottom of the shell rises and falls, slides and penetrates the connected valve stem; the top of the valve stem is fixedly connected to the drive diaphragm, the lower part of the valve stem extends into the interior of the pneumatic valve, and the bottom of the valve stem is radially formed with a valve stem rotor that is connected to the inner wall of the arc guide groove for sliding guidance; one end of the drive spring is pressed and supported on the inner wall of the top surface of the shell, and the other end of the drive spring is pressed and supported on the top surface of the drive diaphragm, and the drive spring and the valve stem are coaxially arranged.

3. The pneumatic differential pressure common rail drive actuator according to claim 1, characterized in that: The air control unit includes a controller, a P1 signal tube, a P2 signal tube and a P3 signal tube, wherein the controller is respectively connected to the exhaust ends of the P1 signal tube and the P2 signal tube, and the air inlet end of the P3 signal tube; the air inlet end of the P1 signal tube is connected to the air inlet end gas pipeline of the pneumatic valve; the air inlet end of the P2 signal tube is connected to the air exhaust end gas pipeline of the pneumatic valve, and the exhaust end of the P2 signal tube is also connected to the inside of the shell of the pneumatic actuator located above the driving diaphragm; the exhaust end of the P3 signal tube is connected to the inside of the shell of the pneumatic actuator located below the driving diaphragm.

4. The pneumatic differential pressure common rail drive actuator according to claim 1, characterized in that: The arc-shaped guide groove is radially opened on the outer wall of the rotor valve core, the groove top of the arc-shaped guide groove is open, the groove bottom of the arc-shaped guide groove is a blind groove, and the central angle between the groove top and the groove bottom of the arc-shaped guide groove is 90°.

5. A method for analyzing the force of the pneumatic differential pressure common rail drive actuator in its execution posture according to claim 1, characterized in that: The following steps are involved: Step 1: Define F as the force acting on the valve stem rotor in the direction of gravity; define f1 and f2 as the force components of F, i.e., the variable direction force applied by the valve stem rotor to the inner wall of the arc guide groove; define θ as the angle between f2 and F; define α as the angle of valve core rotation, which is measured in radians when calculating torque work, and radians are expressed in radα; define h as the displacement of the diaphragm required to drive the valve core to reach a certain rotation angle; define fa as the force component of f1 in the tangential direction, fa = f1 cosθ; define r as the radius of the valve core; and we can obtain: f1=F×sinθ;…………………………………………………………………………(1) Step 2: Since f2 is the friction force, according to the friction force formula: f = μ × N, where μ is the friction factor and N is the normal pressure, according to the track force analysis, the normal pressure of the friction force is the component of F in the normal direction of the track curve, so we can get: f2=μ×F×sinθ;………………………………………………………………(2) Step 3: According to the torque formula: T = F × r × cosθ, we can get: The torque component f1 is: T1=f1×r×cosθ…………………………………………………………(3) The torque component f2 is: T2=f2×r×cos(90°-θ)…………………………………………(4) Among them, the angle between the f2 component and the valve core rotation direction is (90°-θ); Step 4: Since F is the resultant force of f1 and f2, according to the law of conservation of energy, the work done by F is equal to the work done by the two component forces. According to the work calculation formula: W = F × s × cosθ, where F is the force, s is the displacement, and θ is the angle between the force and the direction of motion, we can get: The work done by the resultant force is: W F =F×h, where the direction of the resultant force has no angle with the direction of valve stem movement. According to the formula for calculating rotational work: W=T×radα, where T is the torque and radα is the angular displacement caused by the torque; The work done by the force component f1 is: W f1 =T1×radα, substituting into formula (3), we can get: W f1 =f1×r×cosθ×radα, substituting into formula (1), we can get: IN f1 =F×sinθ×r×cosθ×radα IN f1 =F×r×radα×sinθcosθ………………………………………………………(5) The work done by the force component f2 is: W f2 =T2×radα, substituting into formula (4), we can get: W f2 =f2×r×cos(90°-θ)×radα, substituting into formula (2), we can obtain: W f2 =μ×F×sinθ×r×cos(90°-θ)×radα W f2 =μ×F×r×radα×sinθ×cos(90°-θ)………………………………………(6) Step 5: According to the law of conservation of energy, we can get: W F =W f1 +|W f2 |, since the work done by f2 is loss, its absolute value should be taken when calculating the total work done; substituting it into equations (5) and (6), we get: F×h=F×r×radα×sinθcosθ+|μ×F×r×radα×sinθ×cos(90°-θ)| Further calculation of the formula yields: h=r×radα×sinθcosθ+|μ×r×radα×sinθcos(90°-θ)| h=r×radα×(sinθcosθ+|μsinθcos(90°-θ)|) According to the sine-cosine conversion formula: in: The arc is exactly 90°, so we can get cos(90°-θ)=-sinθ………………………(7) Substituting into formula (7), we can get: h=r×radα×(sinθcosθ+|-μsinθsinθ|) h=r×radα×(sinθcosθ+μsinθsinθ)…………………………………………(8) Step 6: According to the auxiliary angle formula of trigonometric function, we can deduce: Where μ is the metal friction coefficient, which is 0.

25. Substituting it into formula (9) yields the following: Step 7: According to equations (1) and (3), the minimum spool torque is: T1=f1×r×cosθ T=F×r×sinθcosθ According to the trigonometric formula: We can get: Substituting into formula (10) we can get: Where: F=|F KX -F P3 | F KX The loading force of the spring in the pneumatic actuator can be calculated based on the spring coefficient and compression amount; F P3 The loading force of the P3 air pressure on the diaphragm can be calculated based on the P3 imported air pressure value and the force-bearing area of ​​the diaphragm; Therefore, according to formula (11), the minimum torque value required by the valve core at any rotation angle can be calculated.

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