SU364791A1 - DEVICE FOR CONTROLLING PNEUMRAINS - Google Patents

Description

one

Devices are known for controlling valve actuators, which include air supply reducers in its working cavities, pneumatic limit switches of the extreme positions of the valve and of the limit moment; This rotation, as well as a series of Them, connected to Them, are included in the command lines of the gearboxes and are connected in series to the pneumorel of the pneumatic drive control system. The proposed device differs from the well-known in that in the command supply air line to the gearboxes, pressure relief lines are inserted, which turn on when the smoked switches or the torque limit clutch actuate, and the drive motion control and blocking cavities are looped together.

This ensures that the valve is prevented from being destroyed by the pneumatic actuator after its valve body comes to its extreme position (and also eliminates the possibility of the erroneous activation of the pneumatic actuator in two directions simultaneously.

FIG. Figures 1 and 2 show the kinematic and pneumatic schemes of the device.

The reversible air motor / (Fig. 1) is controlled by means of a pneumatic control system 2 by buttons 3-5. The steering wheel 6 of the manual drive sits on the shaft of the worm 7, on which also

The clutch is located at 8 torque limit. The worm gear 9 of the drive is meshed with the gear 10, on the shaft of which the worm 11 is rigidly mounted, working in tandem with the gear 12 of the limit switch boxes.

The cams 13 and 14 of the limit switches 15 and the cam 76 of the position indicator for the valve organ are rigidly fixed on the shaft 17.

The position sensor 18 serves to remotely indicate the position of the locking member. The position cam cam is coupled to the stroke sensor with a lever and a return spring.

The pneumatic switch 19 is overloadable Iarniarno connected to the clutch 8.

Pneumatic lines 20-22 connect the control device to the appropriate limit switches. Pneumatic

line 23 - axis of position sensor 18.

The pneumatic drive control system (Fig. 2) consists of pneumatic relays 24 and 25, which control the gearboxes 26 and 27, which supply air to the propulsion motor 1.

The control system also includes pneumorele 28-31. Button "Open" is connected to the pneumatic switch 28, which is simultaneously a non-return valve, and button 5 "Close - from the pneumatic switch 29, 15 (limit switches). The overload axis protection switch 19 is triggered by a coupling torque moment 5. IlHeBMOpevie 30 and 31 are check valves for the “Stop 4” button.

When you click the Open Coma button, the air enters chambers 32-34, pneumorele 28 and then through the nozzle to the pneumorel membrane 24. The membrane unit 35 of the relay 24, moving down, closes the nozzle 36 and opens the nozzle 37, through which the command air is supplied to a gearbox 26, which opens the air supply to the air motor. At the same time, the control air through the choke 38 is supplied to the balancing cavity 39, as a result of which a positive feedback is created between the cavities 40 and 39 of the relay 24 and the latter is kept on. Limit switch 15 is normally closed. At the approach of the drive to the extreme predetermined position, the limit switch 15 is activated, i.e. the nozzle opens, and air from the cavity 40 of the relay 24 is vented to the atmosphere. The relay 24 returns to its original position, the control air supply to the gearbox 26 is stopped and the air motor / stops.

If it is necessary to stop the drive before it reaches the extreme position, then you should press the button 4 "Groan. In this case, the normally-closed non-return valve 30 will open and expel air through the hub 41 from the cavity 40 of the relay 24.

After actuation of the limit switch 15, the possibility of re-starting the air motor in this direction is excluded, since the control cavity of the relay 24 through the switch 15 will be permanently connected to the atmosphere.

The device is provided with automatic blocking of the axis of erroneous simultaneous activation of the pneumatic actuator from buttons 3 and 5. The blocking is carried out by supplying air from the relay output 24 (chamber 39) to the chamber 42 of relay 25 and from the relay output 25 (camera 43 to the relay chamber 24.

After pressing the button 3, the relay 24 is activated and the pressure from its balancing cavity 39 enters the blocking chamber 42 of the relay 25, which prevents the relay from activating when the butt 5 is pressed. Similarly, when the pneumorele 25 is triggered, the pneumorele 24 will be blocked. the valve on the drive shaft of the pneumatic actuator exceeds the torque value set by the clutch, the increased axial force through the worm to 7 will cause the actuator 8 of the torque limit clutch (Fig. 1) to move will trigger limit switch 19 and stop the air motor.

The limit switch 19 overload protection is connected in parallel with the limit switches 15 and operates in a manner similar to them. .

Subject invention

A device for controlling pneumatic actuators of valves containing feed reducers

air into its working cavities, pneumatic limit switches of the extreme positions (clanan and the limiting moment of its rotation, as well as a number of associated with them, gearboxes included in the command lines and

in series and parallel connected to each other pneumorrhea of a pneumatic actuator control system, characterized in that, in order to prevent the destruction of the valve when its valve is reached in the extreme

positions, as well as excluding the possibility of erroneous activation of the pneumatic actuator simultaneously in two directions, in the supply air line of the command air to the gearboxes, pressure relief lines are inserted, which include

when the limit switches or the torque limiting clutch are activated, the level-transmitting and blocking cavities of the control relay of the drive and the drive units are looped together in pairs.

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