Tandem type film executing mechanism

Abstract

The utility model discloses a tandem type thin film executing mechanism, relates to the technical field of executing mechanisms, and solves the problems that a sealing surface of a valve is easy to damage after output force is increased, and the like. Comprising a plurality of thin film executing mechanism units which are vertically connected in series, floating mechanisms are installed between push rods of the adjacent thin film executing mechanism units, and piston cavities are formed in the lower ends of upper push rods; the floating mechanism comprises a sleeve and a piston rod, the piston rod comprises a piston head, a limiting table and a threaded part, the sleeve sleeves the piston rod and is fixedly connected with the upper push rod, the piston rod is arranged in a piston cavity of the upper push rod to form closed fit, and the threaded part sequentially penetrates through the tray and the diaphragm to be fixedly connected with the lower push rod in a threaded mode. A plurality of thin film executing mechanism units are vertically connected in series, and the output force of each unit is superposed; and the output force is reduced when the valve is close to the tail end of the stroke, so that the overlarge output force is prevented from directly acting on the sealing surface of the valve, and the sealing surface is prevented from being damaged due to over-tight closing of the valve.

Description

Technical Field

[0001] The utility model relates to the technical field of actuators, in particular to a series-type film actuator. Background Art

[0002] Traditional diaphragm actuators are usually single-stage structures, which have limitations when facing some valves that require a large output force to drive. For example, in large-diameter valves or high-pressure differential conditions, single-stage diaphragm actuators are often unable to provide sufficient thrust to ensure the full opening or closing of the valve, thereby affecting the reliability and accuracy of the entire control system. In the related art, the utility model publication number: CN217003320U has disclosed a series-connected pneumatic diaphragm actuator and a series-connected technical solution for a control valve, which to a certain extent solves the problem of insufficient output force. However, during the valve closing process, especially at the end of the stroke, excessive output force will cause the valve to close too tightly, thereby causing damage to the sealing surface of the valve. This damage will not only cause the valve to leak, affecting the normal operation of the process, but also cause the valve to get stuck due to excessive tightening when it starts to open, affecting the normal opening and closing function of the valve. Summary of the Invention

[0003] The purpose of the present invention is to overcome the defects of the prior art, provide a series-type diaphragm actuator, and solve the problem that the valve sealing surface is easily damaged when the output force is increased.

[0004] The technical solution of the present utility model comprises: a plurality of vertically connected diaphragm actuator units, each diaphragm actuator unit comprises a diaphragm, a tray, a push rod, a return spring, an upper shell and a lower shell, the upper shell and the lower shell cover are combined, the return spring is installed between the upper shell and the tray, and the push rods of each diaphragm actuator unit are connected in sequence; a floating mechanism is installed between the push rods of adjacent diaphragm actuator units, the push rod located on the upper side is regarded as the lower push rod, the push rod located on the upper side is regarded as the upper push rod, and a piston cavity is opened at the lower end of the upper push rod; the floating mechanism comprises a sleeve and a piston rod, and the piston rod comprises a piston head, a limit platform and a threaded portion from top to bottom, the sleeve is outer sleeved on the piston rod and fixedly connected to the upper push rod, a floating cavity is formed in the sleeve, the limit platform is abutted against the bottom of the floating cavity, the piston rod is placed in the piston cavity of the upper push rod to form a sealed fit, and the threaded portion passes through the tray and the diaphragm in sequence and is fixedly connected to the lower push rod with a thread.

[0005] By adopting the above technical solution, multiple diaphragm actuator units are connected in series vertically and the output force of each unit is superimposed, which effectively solves the problem of insufficient output force of traditional single-stage diaphragm actuators under large-diameter valves or high pressure difference conditions; in addition, during the valve closing process, especially near the end of the stroke, a relatively closed buffer pressure space is formed in the piston chamber, and the piston head will produce a certain relative movement in the piston chamber, which can absorb and disperse part of the closing output force, thereby reducing the output force of the push rod of each diaphragm actuator unit acting on the valve stem, improving the transmission characteristics of the output force, avoiding excessive output force directly acting on the valve sealing surface, preventing damage to the sealing surface caused by over-tight valve closure, and helping to alleviate the difficulty in starting the valve to open due to over-tight closure.

[0006] In a possible design, an elastic member is disposed on the outer sleeve of the threaded portion, and two ends of the elastic member respectively abut against the sleeve and the tray.

[0007] With the above design, when approaching the end of the stroke, the elastic member will be compressed, and the elastic deformation of the elastic member can further absorb and store part of the energy, playing a certain auxiliary buffering role.

[0008] In a possible design, the elastic member is a conical spring.

[0009] With the above design, the elastic force provided by the conical spring changes according to the amount of deformation as the spring is compressed and deformed, and the elastic force gradually increases, providing a stronger cushioning effect. In addition, it occupies less space, can more effectively utilize space, and optimize the layout of the floating mechanism.

[0010] In a possible design, the elastic member is a disc spring combination.

[0011] With the above design, the disc spring combination has a higher load-bearing capacity and can stably provide a buffering force.

[0012] In a possible design, the limiting platform is in the shape of a nut.

[0013] With the above design, the limit platform facilitates the installation process of the entire floating mechanism, making the assembly between the various components more convenient and efficient; at the same time, the nut-shaped limit platform can adjust the position of the piston rod by rotation, so that the relative position between the limit platform and the lower push rod can be flexibly adjusted, and the initial state of the floating mechanism can be fine-tuned.

[0014] In a possible design, a limit plate is installed below the diaphragm. The limit plate is bowl-shaped, and the bottom surface of the limit plate is in abutment with the lower shell.

[0015] With the above design, the limit plate determines the range of downward movement of the push rod, preventing the push rod from moving downward excessively, protecting the surface of the diaphragm and reducing damage to the diaphragm.

[0016] In one possible design, a height-matching raising block and a fixing member are installed between the upper shell and the lower shell of the adjacent membrane actuator unit. The raising block has an air inlet channel, and the fixing member passes through the adjacent lower shell, the raising block and the upper shell in sequence to form a fixed connection.

[0017] By adopting the above design, the relative height between adjacent diaphragm actuator units can be flexibly adjusted by installing spacers of appropriate height, thereby affecting the floating buffer stroke of the floating mechanism, which helps the system to more accurately control the opening and closing actions of the valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A cross-sectional view of a specific embodiment of the present utility model;

[0019] Figure 2 This is a structural diagram of the initial state of the floating mechanism of the utility model;

[0020] Figure 3 This is a structural diagram of the floating mechanism of the utility model after floating compression;

[0021] Figure 4 This is a partial structural diagram of the utility model in which the elastic member is a disc spring combination;

[0022] Among them, 1. diaphragm; 2. tray; 3. push rod; 31. lower push rod; 32. upper push rod; 321. piston chamber; 4. return spring; 5. upper shell; 6. lower shell; 7. floating mechanism; 71. sleeve; 711. floating chamber; 72. piston rod; 721. piston head; 722. limit platform; 723. threaded part; 73. elastic part; 731. conical spring; 732. disc spring assembly; 8. limit plate; 91. spacer block; 911. intake channel; 92. fixing part. DETAILED DESCRIPTION

[0023] like Figure 1-Figure 4The shown embodiment shows a series-type diaphragm actuator, comprising: a plurality of vertically connected diaphragm actuator units, each of which comprises a diaphragm 1, a tray 2, a push rod 3, a return spring 4, an upper shell 5 and a lower shell 6. The upper shell 5 and the lower shell 6 are covered and an air pressure cavity is formed inside. The return spring 4 is installed between the upper shell 5 and the tray 2. The diaphragm 1 is pushed to reset by the elastic force of the return spring 4, thereby achieving the purpose of resetting the valve state. The push rods of each membrane actuator unit are connected in sequence. The figure shows three membrane actuator units as an example; a floating mechanism 7 is installed between the push rods 3 of adjacent membrane actuator units, and the push rod 3 on the upper side is regarded as the lower push rod 31, and the push rod 3 on the upper side is regarded as the upper push rod 32. The lower end surface of the upper push rod 32 is provided with a piston cavity 321; the floating mechanism 7 includes a sleeve 71 and a piston rod 72. The piston rod 72 includes a piston head 721, a limit platform 722 and a threaded portion 723 from top to bottom. The sleeve 71 is sleeved on the piston rod 72 and fixedly connected to the upper push rod 32. A floating cavity 711 is formed in the sleeve 71. The limit platform 722 is abutted against the bottom of the floating cavity 711. The floating cavity 711 provides the space required for the limit platform 722 to float up and down. The piston rod 72 is placed in the piston cavity 321 of the upper push rod 32 to form a sealed fit. The threaded portion 723 passes through the tray 2 and the diaphragm 1 in sequence and is threadedly fixed to the lower push rod 31. The top of piston head 721 is made of a soft rubber material, enhancing the piston's compression and cushioning effect. Gas enters the space between diaphragm 1 and lower housing 6 of the diaphragm actuator unit, pushing diaphragm 1 upward. Diaphragm 1 pushes on tray 2, which further compresses return spring 4 and drives push rod 3 upward. Because multiple diaphragm actuator units are connected vertically in series, with the push rods of each unit connected sequentially, the output forces of each unit are superimposed, generating a larger combined force to meet the high output force requirements of large-diameter valves or high-pressure differential operating conditions.

[0024] During the valve closing process, when approaching the end of the stroke, the diaphragm 1 continues to act on the lower push rod 31 to move upward, and the piston head 721 of the piston rod 72 continues to move in the piston chamber 321 of the upper push rod 32. Since a relatively closed buffer pressure space is formed in the piston chamber 321, the movement of the piston head 721 in the piston chamber 321 offsets the output force of the lower push rod 31, slowing down the rising speed of the push rod, and reducing the output force transmitted from the push rod of each diaphragm actuator unit to the valve stem, thereby preventing the excessive output force of the series diaphragm actuator from directly acting on the valve sealing surface, extending the service life of the sealing surface, and alleviating the problem of difficulty in starting the valve to open due to over-tight closure.

[0025] In the figure, upward movement is regarded as the closing direction of the valve, which can also be regarded as the opening direction. Then the function of the floating mechanism 7 is at the end of the opening stroke.

[0026] like Figure 2-Figure 4 As shown, the threaded portion 723 is covered with an elastic member 73 (such as a conical spring 731 or a disc spring assembly 732), with its ends respectively resting against the sleeve 71 and the tray 2. Nearing the end of its stroke, the elastic member 73 is compressed, and its elastic deformation further absorbs and stores some energy, providing a certain auxiliary cushioning effect. The conical spring 731 provides different elastic forces depending on the amount of compression deformation; the greater the deformation, the greater the elastic force, thus providing a stronger cushioning effect. The disc spring assembly 732, on the other hand, consists of multiple disc springs connected in series, leveraging its high load-bearing capacity to provide a stable cushioning force. These elastic members 73 absorb and store some energy through elastic deformation, further dispersing and absorbing the closing output force, thereby improving the transmission characteristics of the output force.

[0027] The limit platform 722 is in the shape of a nut. When assembling the floating mechanism 7, a tool (such as a wrench) can be used to operate the nut-shaped limit platform 722 so that it can be abutted against the bottom of the floating cavity 711. At the same time, it is convenient to adjust the position of the piston rod 72, and then fine-tune the initial state of the floating mechanism 7. This adjustment method allows for flexible adjustment of the buffering characteristics of the floating mechanism 7 according to actual working conditions and valve performance requirements, thereby improving the adaptability of the entire system.

[0028] like Figure 1 As shown, a bowl-shaped limit plate 8 is mounted below diaphragm 1, with its bottom surface abutting against lower housing 6. During operation, limit plate 8 acts as a limiter when the push rod moves downward. Limit plate 8 defines the range of downward movement of the push rod, preventing it from moving too far downward, thus avoiding excessive deformation of diaphragm 1, protecting the surface of diaphragm 1, and reducing damage to diaphragm 1 caused by excessive deformation.

[0029] like Figure 1 As shown, a spacer block 91 and a fixing member 92 of an appropriate height are installed between the upper shell 5 and the lower shell 6 of the adjacent diaphragm actuator unit. The air inlet channel 911 in the spacer block 91 ensures that the gas can smoothly enter each diaphragm actuator unit, providing a stable driving source for each unit. The fixing member 92 firmly connects the adjacent lower shell 6, the spacer block 91 and the upper shell 5, ensuring the structural stability of the entire serial diaphragm actuator. The height of the spacer block 91 can be adjusted as needed, thereby affecting the floating buffer stroke of the floating mechanism 7. For example, when the height of the spacer block 91 is higher, the floating stroke of the piston head 721 can be set longer, and the buffering effect has a longer time to act in the closing stroke.

Claims

1. A series-type thin film actuator, characterized in that: include: A plurality of vertically connected film actuator units, each film actuator unit comprising a diaphragm (1), a tray (2), a push rod (3), a return spring (4), an upper shell (5) and a lower shell (6), the upper shell (5) and the lower shell (6) being covered and combined, the return spring (4) being installed between the upper shell (5) and the tray (2), and the push rods of each film actuator unit being connected in sequence; a floating mechanism (7) being installed between the push rods (3) of adjacent film actuator units, the push rod (3) located on the upper side being regarded as a lower push rod (31), and the push rod (3) located on the upper side being regarded as an upper push rod (32), and a piston chamber (321) being provided at the lower end of the upper push rod (32); The floating mechanism (7) includes a sleeve (71) and a piston rod (72). The piston rod (72) includes a piston head (721), a limit platform (722) and a threaded portion (723) from top to bottom. The sleeve (71) is sleeved on the piston rod (72) and fixedly connected to the upper push rod (32). A floating cavity (711) is formed in the sleeve (71). The limit platform (722) is abutted against the bottom of the floating cavity (711). The piston rod (72) is placed in the piston cavity (321) of the upper push rod (32) to form a sealed fit. The threaded portion (723) passes through the tray (2) and the diaphragm (1) in sequence and is threadedly fixedly connected to the lower push rod (31).

2. The tandem diaphragm actuator according to claim 1, characterized in that: The threaded portion (723) is covered with an elastic member (73), and two ends of the elastic member (73) respectively abut against the sleeve (71) and the tray (2).

3. The tandem diaphragm actuator according to claim 2, characterized in that: The elastic member (73) is a conical spring (731).

4. The tandem diaphragm actuator according to claim 2, characterized in that: The elastic member (73) is a disc spring assembly (732).

5. The tandem diaphragm actuator according to claim 1, characterized in that: The limiting platform (722) is in the shape of a nut.

6. The tandem membrane actuator according to claim 1 or 2, characterized in that: A limiting plate (8) is installed below the diaphragm (1), the limiting plate (8) is bowl-shaped, and the bottom surface of the limiting plate (8) is in abutment with the lower shell (6).

7. The tandem membrane actuator according to claim 1 or 2, characterized in that: A height-matching block (91) and a fixing member (92) are installed between the upper shell (5) and the lower shell (6) of the adjacent film actuator unit. An air inlet passage (911) is provided in the block (91). The fixing member (92) sequentially passes through the adjacent lower shell (6), the block (91) and the upper shell (5) to form a fixed connection.

Images