SU651307A1 - Pneumatic controller with tunable dead zone - Google Patents

Description

(54) PNEUMATIC REGULATOR WITH ADJUSTABLE ZONE OF SENSITIVITY

No, deaf cameras which are connected to the first input of the regulator 2.

Depending on which regulator stroke is applied to the setpoint parameter, the input-output characteristic has the form of a forward hysteresis loop. I specify the two boundaries of the dead zone in this regulator — the GC is stable; however, the controller handsets are also very complex here, since the regulator circuit is implemented on six structural elements of four types.

The aim of the invention is to simplify the controller.

The goal is achieved by the fact that it has an odomomembrane pressure amplifier, the nozzle of the first and flow chamber of the second single-membrane element with the spring are connected to the iBTopbtM regulator input, and the flow chamber of the first and nozzle of the second are connected through the choke to the atmosphere and the non-center valve. a single-membrane pressure amplifier, the flow chamber nozzle of which is connected to the regulator OUTPUT.

A schematic diagram of the regulator is shown in the drawing.

The regulator contains single-membrane elements with spring 1 and 2, constant chokes 3 and 4 and one-membrane pressure amplifier 5. The first input of the regulator Pj is connected to the deaf chambers of the elements 1 and 2, the second input of the RP-RW relay is connected to the nozzle of the 1 and the flow chamber element 2, the output of the regulator F is connected via a dongle 3 to the power source, and through the contact of the pressure amplifier 5 is connected to the atmosphere, and the flow chamber of the amplifier 5 is connected to the atmosphere, and the deaf chamber of the amplifier 5 is connected to the atmosphere through throttle 4 The parallel contacts of elements 1 and 2 are connected to the input P t, the spring in element 1 sets the negative displacement D, and the spring in element 2 sets the positive displacement d 2

The regulator works as follows.

Let the setting of the adjustable parameter is given at the input of PJ, and the current value of the adjustable paral-parameter at the input of P,; in this case, element 1 specifies the lower one: the limit of the dead zone, and element 2 the upper one.

In the initial state, when P2 O, the contact of elements 1 and 2 is open and the amplifier S camera is deaf, through throttle 4 is in communication with the atmosphere, there is no pressure, the contact of amplifier 5 is open and output P is directly connected with the atmosphere, so that PJ O.

As soon as the adjustable parameter starts to grow and becomes such that PJ P j + D 2 the contact of element 2 closes and the camera 5 is deaf, the amplifier 5 communicates directly with the input P2, then the amplifier 5 is switched on according to an unbalanced circuit penetrated into its blind pressure chamber P to cover the amplifier 5, so that the control amplifier 5 is opened and the output Pd through the choke 3 turns out to be connected to the power source, the output of the regulator is pressure, i.e. Pd si. In addition, the pressure P from the output of the element 2 enters the flow chamber of the element 1, the contact

which closes at P

Since this force 6 is considered a moment is fulfilled, the chamber 5 of the element 5 turns out to be in communication with the input P through the contacts of both single-membrane elements with a spring.

If the pressure P decreases further, it becomes such that the + D 2 fo contact of element 2 is opened, but the amplifier chamber is deaf to remain communicated with the input P2 through the contact of element 1, so that, as before, PI 1..

If further the pressure Pg continues to decrease, it will become so.

2

- L

then contact ele

CH1U

one

Ment 1 opens; The connection of the deaf chamber of the amplifier 5 with the inlet of the RL is interrupted and the connection between the choke (atmosphere) and the atmosphere remains, the pressure in the deaf chamber of the amplifier 5 becomes equal to zero and the contact of the amplifier 5 is closed and the output Pg is directly connected with the atmosphere will disappear, so that RO. The device circuit has returned to its original state, the work cycle has been completed.

Thus, when the adjustable parameter P is changed from smaller values to large values, the output j of the controller switches from 0 to, as

only R / + D

at

56

changing the adjustable parameter P from 6 °; one value to a smaller regulator output Рл switches from to О as soon as Pj-i Pj - D; consequently, the regulator circuit implements a direct hysteresis loop with a dead zone defined within. PI-D I RZ.

Now suppose that the setting of the controlled parameter is applied to the input P-, and the current value of the adjustable parameter is fed to the input P,; in this case, element 1 sets the upper, and element 2 sets the lower edge of the insensitive zone

In the initial state, when P 0, the contacts of elements 1 and 2 are closed and the chamber of amplifier 5 is deaf through them to input P to the ° tact of amplifier 5 is open and output P is connected via a choke 3 to a power source, so that P 1.

As soon as the adjustable parameter starts to increase and becomes such that P P2 - A 2 contact of element 2 is opened, however, the camera of amplifier 5 is deaf and remains communicated with input P through contact of element 1 so that P 1 is still.

If, in the future, the adjustable parameter continues to increase, it becomes such that PJ P; 2 the contact of element 1 is opened, the connection of the deaf chamber of amplifier 5 with the input P is interrupted; the deaf chamber of amplifier 5 will remain communicated (via throttle 4) only with the atmosphere, the pressure in it will disappear, the contact of amplifier 5 will close and the output P will communicate directly with the atmosphere, the pressure on it will disappear, so that P2, .0.

If in the future the adjustable parameter, decreasing, becomes such that Р -i P2, the contact of element 2 is closed, pressure P2 enters the deaf chamber of amplifier 5, its contact is opened and output P- appears to communicate (via throttle 3) only with the power source , at the outlet according to pressure; those. Pj 1.

In addition, the RE pressure will flow into the flow chamber of the cell. 1, since in this case PI - PX 4 1, then the contact of element 1 is closed and the camera 5 of the amplifier will be deaf

puppy with input p / j. through contacts, about 1 x elements; as before, P 1, The device circuit has returned to its original state, the work cycle is completed, Thus, with a change in per; parameter P from lower values to large, the output of the regulator Pd switches from 1 to O as soon as PI 2 D 1 when changing

of the adjustable parameter Pj from large connections to smaller outputs of the regulator Pd switches from O to as soon as P | Pn - D therefore, the regulator circuit realizes

reverse hysteresis loop with dead band, set within

The constructive benefits of a controller are weight reduction,

size, as well as a corresponding reduction in the cost of the regulator relative to the known controller. In addition, a single-membrane amplifier is much simpler and more reliable than the opposed elements of a known re-

the hum of the torus.

Claims (2)

1. USSR author's certificate N9 446029, cl. С | 05 611/54, 1972., 2. USSR author's certificate NO 411433, cl. q 05 b 11/50, 1972. j -3 H s