SU583445A1 - Pneumatic device for determining derivative sign - Google Patents

Description

(54) PNEUMATIC DEVICE FOR DETERMINATION. DERIVED SIGN

Comparison element 1, a constant choke 6, an adjustable choke 5 and a pneumatic capacitance 4 are differentiated aveio, o,

The comparative i seal chamber is connected to the inlet channel 5. The minus cell of element 1 (the output of the differential link) is connected to the input chamber of the first element of comparison 2, through a nozzle with the atmosphere, through the choke 6 to the power supply channel and through an adjustable choke 5 with air capacity 4, to the second minus chamber of the element of comparison 1 (late negative camera). feedback) and the input chamber of the element of comparison 2, the nozzles of the element 2 are connected to the power supply channel through the throttles 7 and 8 and with the corresponding control cameras of the second element of the comparison 3. The cameras of the element are compared and 2 are connected to the corresponding nozzles of the three-membrane Relay Neither through the chokes 9 and 10 together with the atmosphere. Flow chambers of the 1D relay are also connected to the atmosphere. The pressure of the subchamber is applied to one of the control chambers, and the control input is connected to the command signal channel P. One nozzle ele. Comparison 3 is connected to the power supply, second to the atmosphere, and flow chambers (output of the second element 3) to the output channel of the device.

The device works in the following way. In the static mode (the input signals of the comparison element 2 are equal to each other, and the output signal of the device is determined by the value of the signal P. At Pj O, the pressure of the backwater causes the nozzle in one of the flow chambers of relay 11 to be closed and the nozzle in the other to open. Pressure in One of the flow chambers of alement 2 is Raino O, and in the other flow chamber of the same element it is 40-60 mm of water g. because the supply air flowing through the throttle 7 is discharged only through the throttle 9. Under the action of this pressure memnoan block alement comparison 2 is displaced downward, pressure P after throttles 7 is less than pressure PJJ after throttles 8. In re-launch, there is an unbalance at the inputs of alem (yyych comparison 3 output signal of the device is 1. When P 1 through nozzle of relay 11, one of the the flow chambers of the element of comparison 2, and in another of this element, a pressure of 40-60 mm of water line is established. The membrane unit of the element of comparison 2 is swept up, C Ru and 0.

In dynamics (Rvh

/ O) as a result

The differentiations of the input signal R ,. the unbalance of the input signals of the comparing element 2 appears. Since the effective areas for which these signals are much more (c) greater than the effective areas of the membranes of the flow chambers of this element, the position of the membrane unit is determined by the sign of this unbalance. As Rj increases, the pressure in the input chamber of the comparison element 2 is greater than in another input chamber, and regardless of the value of the signal R, the membrane unit

Comparison element 2 is in the top

position, 1 P2 and C O. When Γ decreases, the pressure in the input chamber of the element of comparison 2 becomes less than the pressure in the other chamber, which ensures.

R.

and ultimately 1

one.

I

Thus, in dynamics, the value of the output signal, y (the device is determined by the direction of change of the input

signal P. „, and in statics - the value of the discrete command signal Pj,.

Claims (1)

The introduction of a second cascade of amplifiers and constant chokes instead of adjustable throttles with very low conductivity and repeaters with a shift allows to simplify the design and especially the adjustment of the device, increase its sensitivity, as well as increase reliability by using elements with more stable characteristics. Formula of the invention Pneumatic device to determine the sign of the derivative, which keeps the differentiating element connected to the input channel, the output and the delayed negative reverse chamber second communication are connected to the chambers of the first comparison element and trehmembrannoe relay control input coupled to a command signal channel, characterized in that, in order to simplify the device and increase its accuracy in not "set vtory comparing element and four throttles; each of the nozzles of the first comparison element is connected to the control Chambers of the second comparison element and connected via a choke to the feed channel; Each flow chamber of the first comparison element is connected through the choke with the atmosphere and directly with the corresponding nozzle of the three-membrane relay, the flow chambers of which are connected to the atmosphere, and the output of the second comparison element is connected to the output channel of the device. Sources of information taken into account in the examination :. " 1, Berevps T, K., | Efremova T., K., Tagaevska A. A., Yuditsky S. A, Elements and pneumatic automation schemes, M., Mashinastroe nne, 1976,. 14O, rice, 1086, 1 2, USSR Authority license 9 363071, cl. e 05 B 13/00, 1973,