Improvement method of shifting fork structure in driving device for cutting off butterfly valve pipeline

Abstract

The invention discloses an improvement method of a shifting fork structure in a driving device for cutting off a butterfly valve pipeline, a shifting fork is connected with a control shaft, the driving device comprises a pneumatic spring device, a transmission rod, the shifting fork and a shifting fork limiting device, the transmission rod capable of horizontally moving in the axial direction is arranged on one side of the control shaft, one end of the transmission rod is connected with the pneumatic spring device, and the other end of the transmission rod is connected with the shifting fork limiting device. A shifting fork limiting device is arranged at the other end; one end of the shifting fork is connected with the control shaft and can drive the control shaft to rotate, an extending notch is horizontally formed in the middle of the shifting fork in the direction of the center line, and a pin shaft is arranged on the transmission rod and arranged in the notch of the shifting fork; according to the three specific improvement methods, the eccentric angle and the deflection angle are set, after the size of the shifting fork is slightly changed, the torque curve of the shifting fork can be greatly improved, the output torque at the fully-closed position is increased, the output torque at the fully-open position is reduced, and force waste is greatly reduced.

Description

Technical Field

[0001] The invention belongs to the field of butterfly valve pipeline control, and in particular relates to a method for improving a shift fork structure in a driving device for cutting off a butterfly valve pipeline. Background Art

[0002] In some equipment, when controlling the butterfly valve pipeline, due to the needs of actual working conditions, the torque required when the disc plate leaves the fully closed position is relatively large, so it is hoped that the driving device can output a larger torque to open the disc plate to maintain the conduction of the pipeline; when the disc plate leaves the fully open position, the required driving force is smaller, so it is hoped that the driving device can reduce the output torque; under conventional design, the output torque of the driving device is insufficient when it is in the fully closed position, and the output torque has a large redundancy when it is in the fully open position, which will cause great energy waste and reduce the service life of the driving device; therefore, there is an urgent need for an improved method for the fork structure in the driving device for cutting off the butterfly valve pipeline. Summary of the invention

[0003] Purpose of the invention: The purpose of the present invention is to provide a method for improving the fork structure in a driving device for cutting off a butterfly valve pipeline. The structural form of the fork is improved to meet the needs of actual working conditions and increase the service life of the butterfly valve.

[0004] Technical solution: The present invention provides an improved method for the fork structure in a driving device for cutting off a butterfly valve pipeline, wherein the fork is connected to a control shaft in the driving device, and when the control shaft rotates 90° clockwise, the butterfly plate rotates accordingly, the passage is closed, and the fluid in the pipeline is blocked; when the control shaft rotates 90° counterclockwise, the butterfly plate rotates in the opposite direction accordingly, the passage is opened, and the fluid in the pipeline is conducted; the entire movement process includes: a pneumatic spring device, a transmission rod, a fork, and a fork limiting device, wherein a transmission rod that moves horizontally along the axial direction is provided on one side of the control shaft, one end of the transmission rod is connected to the pneumatic spring device, and the other end is provided with the fork limiting device; one end of the fork is connected to the control shaft and can drive the control shaft to rotate, and the fork An extended notch is horizontally arranged in the middle part along the center line direction, and a pin is arranged on the transmission rod, and the pin is placed in the notch of the shift fork; when the spring pneumatic device is filled with gas, it drives the transmission rod to move horizontally to the left, and drives the shift fork and the control shaft to rotate, thereby disconnecting the fluid passage; when the spring pneumatic device is discharged from the gas, the spring group in the spring pneumatic device releases potential energy, drives the transmission rod to move horizontally to the right, and drives the shift fork and the control shaft to rotate, thereby connecting the fluid passage; three shift fork improvement methods are included, namely, setting an eccentricity ratio and a deflection ratio, and setting an eccentricity and setting a deflection; thereby, when the spring pneumatic device drives the shift fork to open and close the butterfly valve pipeline, the output torque of the shift fork is increased when the shift fork is in the fully closed position, and the output torque of the shift fork is reduced when the shift fork is in the fully open position.

[0005] Furthermore, the first method for improving the shift fork is as follows: the shift fork is deflected by β, and the opening of the shift fork is adjusted from (-45°) to (45°), that is, (valve closed position, opening 0°) to (valve open position, opening 90°) symmetrical rotation, to (-45°-β) to (45°-β) asymmetrical rotation, and the torque value is calculated. The output torque calculation formula of the pneumatic spring device is as follows:

[0006]

[0007] Wherein, T is the output torque, η represents the system efficiency, F represents the spring force acting on the transmission shaft, L represents the center distance between the transmission shaft and the valve shaft, and α represents the rotational angular travel of the shift fork.

[0008] Furthermore, the spring force F acting on the transmission shaft is calculated as follows:

[0009] F=k(X+Δx)

[0010] Wherein, k is the combined spring coefficient of the pneumatic spring device, X is the combined spring preload, and Δx is the spring deformation;

[0011] Δx is considered according to the rotation angle as follows:

[0012] Δx=Ltan(45°+β)-Ltan|α|, α∈(-45°-β, 0°)

[0013] Δx=Ltan(45°+β)+Ltanα, α∈(0°, 45°-β)

[0014] k is the combined spring coefficient of the pneumatic spring device, and the calculation formula of the parallel spring stiffness coefficient is:

[0015] k1=k'+k"

[0016] The formula for calculating the stiffness of the series spring is:

[0017]

[0018] k' is the stiffness coefficient of spring I; k" is the stiffness coefficient of spring II. The calculation formula of the stiffness coefficient of the spring is:

[0019]

[0020] in is the winding ratio; D2 is the middle diameter of the spring; d is the spring wire diameter.

[0021] Furthermore, under the action of spring force, the torque calculation formula for closing the valve is:

[0022]

[0023] Furthermore, the second method for improving the shift fork is as follows: the shift fork is eccentric, the shift fork is adjusted to an eccentric structure in which the notch provided on the shift fork and the symmetric center of the shift fork are deflected by an angle of θ, and the torque value thereof within the limit position is calculated; the output torque calculation formula of the pneumatic spring device is:

[0024]

[0025] Wherein, T is the output torque, η represents the system efficiency, F represents the spring force acting on the transmission shaft, L represents the center distance between the transmission shaft and the valve shaft, α represents the rotational angular stroke of the shift fork, and θ represents the eccentric angle of the shift fork;

[0026] According to the force vector triangle, we can deduce:

[0027]

[0028] It can be deduced from this that the output torque in the fully open direction is:

[0029]

[0030] According to the force vector triangle, we can deduce:

[0031]

[0032] It can be deduced from this that the output torque in the fully closed direction is:

[0033]

[0034] Furthermore, the spring force acting on the transmission shaft is:

[0035] F=k(X+Δx)

[0036] Wherein, k is the combined spring coefficient of the pneumatic spring device, X is the combined spring preload, i.e. the fully closed position of the valve, and Δx is the spring deformation;

[0037] Δx=L-Ltan|α|, α∈(-45°, 0°)

[0038] Δx=L+Ltanα, α∈(0°, 45°0.

[0039] Furthermore, under the action of spring force, the torque calculation formula for closing the valve is:

[0040]

[0041] Furthermore, the third method for improving the shift fork is specifically as follows: according to the output torque calculation formula of the pneumatic spring device:

[0042]

[0043] Where, T is the output torque, η is the system efficiency, F is the spring force acting on the rack shaft, k is the spring stiffness, L is the center distance between the rack shaft and the valve shaft, α is the angular travel of the fork rotation, β is the deflection angle of the fork; θ is the eccentricity angle;

[0044] The output torque in the fully open direction is:

[0045]

[0046] The output torque in the fully closed direction is:

[0047]

[0048] Furthermore, the spring force acting on the transmission shaft is:

[0049] F=k(X+Δx)

[0050] In the formula, k is the combined spring coefficient of the pneumatic spring device, X is the combined spring preload, and Δx is the spring deformation; Δx in the formula is considered as follows:

[0051] Δx=L[tan(45°+β)-tan|α|]α∈(-45°-β, 0°)

[0052] Δx=L[tan(45°+β)+tanα]α∈(0°, 45°-β)

[0053] Under the action of spring force, the torque calculation formula for closing the valve is:

[0054]

[0055] α∈(-45°-β,0°

[0056]

[0057] α∈(0°,45°-β).

[0058] Furthermore, the spring pneumatic device includes a cylinder body, a piston, and a spring group arranged on one side of the piston with a transmission rod, and the spring groups are connected in parallel and then in series.

[0059] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: The present invention reasonably optimizes and designs the eccentric angle and deflection angle of the driving position fork. After slightly changing the size of the fork, it can greatly improve its output torque curve, increase the output torque at the fully closed position, and reduce the output torque at the fully open position, thereby meeting the torque requirement of the valve during the opening and closing process. Under the prior art, the output torque of the fork limit mechanism based on the spring pneumatic device is usually insufficient at the fully closed position, requiring external supplementation, which increases the complexity of the equipment structure; and the output torque at the fully open position has a large redundancy, which not only causes great energy waste, but also reduces the service life of the driving device. The advantage of the present invention is that the output torque is affected by the changes in the eccentric angle and deflection angle of the fork, thereby meeting the required functions of the device without significantly changing the structure and spatial dimensions of the device. The method is simple in structure, efficient and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 1. The overall structure of the embodiment of the present invention is shown in the figure: 1. control shaft, 2. bottom plate, 3. shift fork, 4. pin shaft, 5. transmission rod, 6. pneumatic spring device, 7. sleeve, 8. end cover, 61. cylinder body, 62. piston, 63. nut, 64. spring assembly.

[0061] Figure 2 This is a schematic diagram of the shift fork of the first improved solution.

[0062] Figure 3 This is a schematic diagram of the shift fork of the second improved solution.

[0063] Figure 4 This is the schematic diagram of the fork force analysis of the first improved solution.

[0064] Figure 5 This is a schematic diagram of the force analysis of the shift fork in the fully open position for the second improvement scheme.

[0065] Figure 6 This is a schematic diagram of the force analysis of the shift fork in the fully closed position for the second improved solution.

[0066] Figure 7 This is a schematic diagram of the force analysis of the shift fork in the fully open position for the third improvement scheme.

[0067] Figure 8 This is a schematic diagram of the force analysis of the shift fork in the fully closed position for the second improved solution.

[0068] Fig. 9 This is a schematic diagram of the output torque of the shift fork of the first improved solution.

[0069] Fig.10 This is a schematic diagram of the output torque of the shift fork of the second improved solution.

[0070] Fig.11 This is a schematic diagram of the output torque of the shift fork of the third improved solution. DETAILED DESCRIPTION

[0071] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0072] The present invention relates to a driving device capable of cutting off a butterfly valve pipeline, which is connected to a control shaft 1 for controlling the rotation of a butterfly plate in a butterfly valve. When the control shaft 1 rotates 90° clockwise, the butterfly plate rotates accordingly, the passage is closed, and the fluid in the pipeline is blocked. When the control shaft 1 rotates 90° counterclockwise, the butterfly plate rotates in the opposite direction accordingly, the passage is opened, and the fluid in the pipeline is conducted. The entire movement process includes: a shift fork 3, a transmission rod 5, and a pneumatic spring device 6. A transmission rod 5 that can move horizontally along the axial direction is provided on one side of the control shaft 1. One end of the transmission rod 5 is connected to the pneumatic spring device 6; one end of the fork 3 is connected to the control shaft 1 and can drive the control shaft 1 to rotate. The fork 3 is horizontally provided with an extended notch in the middle along the center line direction. The transmission rod 5 is provided with a pin 4, and the pin 4 is placed in the notch of the fork 3. When the spring pneumatic device 6 is filled with gas, it drives the transmission rod 5 to move horizontally to the left, and drives the fork 3 and the control shaft 1 to rotate. After the control shaft 1 drives the disc plate to rotate 90°, the fluid passage in the butterfly valve is disconnected. When the spring pneumatic device 6 discharges gas, the spring group 64 in the spring pneumatic device 6 releases potential energy, drives the transmission rod 5 to move horizontally to the right, and drives the fork 3 and the control shaft 1 to rotate, thereby driving the disc plate to rotate in the opposite direction to conduct the fluid passage; the first method of improving the fork is to deflect the fork (the deflection is β), and adjust the opening of the fork from a symmetrical rotation of -45° (valve closed position, opening 0°) to 45° (valve open position, opening 90°) to an asymmetrical rotation of (-45°-β) to (45°-β). ; The second method of improving the shift fork is to eccentric the shift fork, and the shift fork is adjusted to an eccentric structure in which the notch provided on the shift fork and the symmetric center of the shift fork are deflected at an angle of θ, and the line connecting the center point of the shift fork sleeve and the center point of the pin shaft 4 is symmetrical with the vertical line of the transmission rod 5, and an eccentric angle θ exists between the center line of the notch of the shift fork 3 and the center line of the shift fork; All three improvement schemes can increase the output torque of the shift fork 3 when it is in the fully closed position, and reduce the output torque of the shift fork 3 when it is in the fully open position when the spring pneumatic device 6 drives the shift fork 3 to open and close the butterfly valve pipeline.

[0073] Practical Examples

[0074] Solution 1

[0075] In a traditional butterfly valve drive device, since the torque required when the disc plate leaves the fully closed position is relatively large, it is hoped that the drive device can output a larger torque. However, the unimproved fork cannot meet the requirement under actual working conditions, so the fork is deflected. The following is a practical example.

[0076] β=10°

[0077] 1. γ=0°,α=-55°,

[0078] 2. γ=15°,α=-40°,

[0079] 3. γ=30°,α=-25°,

[0080] 4. γ=45°,α=-10°,

[0081] 5. γ=60°,α=5°,

[0082] 6. γ=75°,α=20°,

[0083] 7. γ=90°,α=35,

[0084] Solution 2

[0085] In a traditional butterfly valve drive device, since the torque required when the disc plate leaves the fully closed position is relatively large, it is hoped that the drive device can output a larger torque. However, the traditional fork structure cannot meet the demand under actual working conditions, so the fork is set eccentrically. The following is a practical example.

[0086] θ=35°

[0087] 1. γ=0°, α=-45°, M1=6.67ηkLx=9349N·m

[0088] 2. γ=15°, α=-30°, M2=2.24ηkL(x+0.42L)=34143,

[0089] 3. γ=30°, α=-15°, M3=1.32ηkL(x+0.73L)=21314,

[0090] 4. γ=45°, α=0°, M4=ηkL(x+L)=16945,

[0091] 5. γ=60°, α=15°, M5=0.9ηkL(x+1.27L)=15956,

[0092] 6. γ=75°, α=30°, M6=0.95ηkL(x+1.58L)=17707,

[0093] 7. γ=90°, α=45°, M7=1.18ηkL(x+2L)=2343

[0094] Option 3

[0095] In the traditional butterfly valve drive device, since the torque required when the disc plate leaves the fully closed position is relatively large, it is hoped that the drive device can output a larger torque. However, the traditional fork structure cannot meet the demand under actual working conditions. Therefore, the two methods of eccentricity and deflection setting of the fork are combined. The following is a practical example.

[0096] The results of calculating the torque when β = 10° and θ = 20° are as follows;

[0097] 1. γ=0°, α=-55°, M1=6.33ηkLx=8872N·m

[0098] 2., γ=15°, α=-40°, M2=2.45ηkL(x+0.59L)=3856

[0099] 3. γ=30°, α=-25°, M3=1.47ηkL(x+0.96L)=2472

[0100] 4. γ=45°, α=-10°, M4=1.1ηkL(x+1.25L)=1943

[0101] 5. γ=60°, α=5°, M5=0.98ηkL(x+1.52L)=1808

[0102] 6. γ=75°, α=20°, M6=1ηkL(x+1.79L)=1924

[0103] 7. γ=90°, α=35°, M7=1.19ηkL(x+2.13L)=2408

[0104] The three improvement methods of the present invention are respectively to set the eccentric angle and the deflection angle. After slightly changing the size of the fork, its torque curve can be greatly improved, the output torque at the fully closed position can be increased, and the output torque at the fully open position can be reduced.

Claims

1. A method for improving the fork structure in a driving device for cutting off a butterfly valve pipeline, characterized in that: The shift fork is connected to the control shaft in the driving device. When the control shaft rotates 90° clockwise, the butterfly plate rotates accordingly, the passage is closed, and the fluid in the pipeline is blocked. When the control shaft rotates 90° counterclockwise, the butterfly plate rotates in the opposite direction, the passage is opened, and the fluid in the pipeline is conducted. The entire movement process includes: a pneumatic spring device, a transmission rod, a shift fork, and a shift fork limiting device. A transmission rod that moves horizontally along the axial direction is provided on one side of the control shaft. One end of the transmission rod is connected to the pneumatic spring device, and the other end is provided with the shift fork limiting device. One end of the shift fork is connected to the control shaft and can drive the control shaft to rotate. The middle part of the shift fork is horizontally provided with an extension along the center line direction. The notch is provided with a pin on the transmission rod, and the pin is placed in the notch of the shift fork; when the spring pneumatic device is filled with gas, it drives the transmission rod to move horizontally to the left, and drives the shift fork and the control shaft to rotate, thereby disconnecting the fluid passage; when the spring pneumatic device is discharged from the gas, the spring group in the spring pneumatic device releases potential energy, drives the transmission rod to move horizontally to the right, and drives the shift fork and the control shaft to rotate, thereby connecting the fluid passage; three shift fork improvement methods are included, namely, setting an eccentricity ratio and a deflection ratio, and setting an eccentricity and setting a deflection; thereby, when the spring pneumatic device drives the shift fork to open and close the butterfly valve pipeline, the output torque of the shift fork at the fully closed position is increased, and the output torque of the shift fork at the fully open position is reduced.

2. The method for improving the fork structure in the driving device for cutting off the butterfly valve pipeline according to claim 1, characterized in that: The first method for improving the shift fork is as follows: the shift fork is deflected by β, and the opening of the shift fork is adjusted from (-45°) to (45°), that is, (valve closed position, opening 0°) to (valve open position, opening 90°) symmetrical rotation, to (-45°-β) to (45°-β) asymmetrical rotation, and the torque value is calculated. The output torque calculation formula of the pneumatic spring device is as follows: Wherein, T is the output torque, η represents the system efficiency, F represents the spring force acting on the transmission shaft, L represents the center distance between the transmission shaft and the valve shaft, and α represents the rotational angular travel of the shift fork.

3. The method for improving the fork structure in the driving device for cutting off the butterfly valve pipeline according to claim 2, characterized in that: The spring force F acting on the transmission shaft is calculated as follows: F=k(X+Δx) Wherein, k is the combined spring coefficient of the pneumatic spring device, X is the combined spring preload, and Δx is the spring deformation; Δx is considered according to the rotation angle as follows: Δx=Ltan(45°+β)-Ltan|α|, α∈(-45°-β, 0°) Δx=Ltan(45°+β)+Ltanα, α∈(0°, 45°-β) k is the combined spring coefficient of the pneumatic spring device, and the calculation formula of the parallel spring stiffness coefficient is: k1=k'+k" The formula for calculating the stiffness of the series spring is: k' is the stiffness coefficient of spring I; k" is the stiffness coefficient of spring II. The calculation formula of the stiffness coefficient of the spring is: in is the winding ratio; D2 is the middle diameter of the spring; d is the spring wire diameter.

4. The method for improving the fork structure in a driving device for cutting off a butterfly valve pipeline according to claim 2, characterized in that: Under the action of spring force, the torque calculation formula for closing the valve is:

5. The method for improving the fork structure in a driving device for cutting off a butterfly valve pipeline according to claim 1, characterized in that: The second method for improving the shift fork is as follows: eccentrically adjusting the shift fork to an eccentric structure in which the notch provided on the shift fork and the symmetric center of the shift fork are deflected by an angle of θ, and calculating the torque value within the limit position; the output torque calculation formula of the pneumatic spring device is: Wherein, T is the output torque, η represents the system efficiency, F represents the spring force acting on the transmission shaft, L represents the center distance between the transmission shaft and the valve shaft, α represents the rotational angular stroke of the shift fork, and θ represents the eccentric angle of the shift fork; According to the force vector triangle, we can deduce: It can be deduced from this that the output torque in the fully open direction is: According to the force vector triangle, we can deduce: It can be deduced from this that the output torque in the fully closed direction is:

6. The method for improving the fork structure in the driving device for cutting off the butterfly valve pipeline according to claim 5, characterized in that: Spring force acting on the transmission shaft: F=k(X+Δx) Wherein, k is the combined spring coefficient of the pneumatic spring device, X is the combined spring preload, i.e. the fully closed position of the valve, and Δx is the spring deformation; Δx=LL tan|α|, α∈(-45°, 0°) Δx=L+L tanα, α∈(0°, 45°) 7. The method for improving the fork structure in a driving device for cutting off a butterfly valve pipeline according to claim 5, characterized in that: Under the action of spring force, the torque calculation formula for closing the valve is:

8. The method for improving the fork structure in a driving device for cutting off a butterfly valve pipeline according to claim 1, characterized in that: The third method for improving the shift fork is as follows: according to the torque calculation formula of the pneumatic spring device: Where, T is the output torque, ηη is the system efficiency, F is the spring force acting on the rack shaft, k is the spring stiffness, L is the center distance between the rack shaft and the valve shaft, α is the angular travel of the fork rotation, β is the deflection angle of the fork; θ is the eccentricity angle; The output torque in the fully open direction is: The output torque in the fully closed direction is:

9. The method for improving the fork structure in the driving device for cutting off the butterfly valve pipeline according to claim 8, characterized in that: Spring force acting on the transmission shaft: F=k(X+Δx) In the formula, k is the combined spring coefficient of the pneumatic spring device, X is the combined spring preload, and Δx is the spring deformation; Δx in the formula is considered as follows: Δx=L[tan(45°+β)-tan|α|]α∈(-45°-β, 0°) Δx=L[tan(45°+β)+tanα]α∈(0°, 45°-β) Under the action of spring force, the torque calculation formula for closing the valve is:

10. The method for improving the fork structure in a driving device for cutting off a butterfly valve pipeline according to claim 8, characterized in that: The spring pneumatic device comprises a cylinder body, a piston and a spring group arranged on one side of the piston with a transmission rod. The spring groups are connected in parallel and then in series.

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