SU830329A1 - Flow governor - Google Patents

Description

one

This invention relates to automatic regulation and can be used to control the flow of liquid and gaseous media.

A known liquid and gaseous fluid flow regulator, comprising an electric actuator, which is a reversible single-phase electric motor, in which two end positions corresponding to the open and closed states of the control valve are fixed, using limit switches that turn off the corresponding circuits supplying power to the control winding of the reversing motor. The design of such a regulator contains a series of mechanical parts and connections that first convert electrical signals into the rotational motion of the rotor of an electric motor, and then into the reciprocating movement of the regulator. The rotor of the electric motor is connected to the regulator via a reducer and a clutch of the limiting moment with the help of pin and key connections. To limit the extreme positions of the regulator, the regulator is equipped with a limit switch 1 "m and a cam mechanism 1.

However, the presence of mechanical connections reduces the regulator's regulator.

The closest in technical essence to the present invention is a regulator containing an electric control coil and a core of magnetically hard, magnetic

0 the field of which closes on the magnetic fluid placed in the elastic membrane 2.

The disadvantage of such a constructive decision of the controller is the lack of fixation of the Open position. The Open position corresponds to the demagnetized state of the hard magnetic material of the core, however, the further arrival of the pulse

0 current to open the valve leads to the magnetization of the core in the opposite direction of the following poles and, consequently, to the closure of the valve. In the final account, the regulation around the maximum flow rate of the medium will be violated. .

The purpose of the invention is to increase the reliability of the controller.

The goal is achieved by the fact that the controller contains the second

a hollow cylindrical core mounted coaxially inside the first one wherein the first hollow cylindrical core is made of a material with a coercive magnetization force smaller than the material of the second core ..;,

The drawing shows the design of the flow regulator.

The controller contains an electromagnet 3 located between the input 1 and the output 2 naTpy6i, with the first hollow cylindrical core 4, inside which is fixed an elastic shell 5 forming with the first core. 4, chamber b, filled with ferromagnetic fluid, as well as a second hollow cylindrical core 7 mounted coaxially inside the first one. The edges of the elastic sheath 5 are attached to the first core by 4 flanges of the pipes 1 and 2, screwed together between themselves.

The flow regulator operates as follows.

The regulator with the initial pressure is supplied to the working medium, which passes through the space bounded by the shell 5. The hydrodynamic or gas-dynamic resistance of the space bounded by the shell 5 determines the flow rate of the medium. This resistance, in turn, depends on the position of the shell 5 on which two forces act: the strength of the working medium on one side and the magnetic force of the ferromagnetic liquid with the total field of cores 4 and 7. The change in the total field is controlled by magnetization or demagnetization of the first core 4, the coercive magnetization force of which is less than the coercive force of demagnetization of the second core. 7, the initial magnetization of which is produced during the manufacture on a special stand. When the core magnetizes the core 4 with current pulses transmitted through the electromagnet 3 with the magnetization of the core 4 in the direction opposite to the magnetization direction of the core 7, the regulator operates in the Open position. In this case, the total magnetic field interacting with the ferromagnetic fluid in the working gap decreases with each pulse. The development of the opening control is considered from the time corresponding to the maximum closing. This position is caused by the maximum gradient of the magnetic field in the working gap, determined by the sum of the magnetic fields of the core 7 and core 4, magnetized by its maximum value in the direction coinciding with the direction of the core field 7. The force of interaction

The maximum magnetic field of the cores 4 and 7 with a ferromagnetic fluid creates such opposition to the pressure of the working medium at which the regulator is closed. At the initial moment, each current pulse to open partially demagnetizes the core 4, reducing the total magnetic field and its gradient in the working gap, reducing its interaction with the ferromagnetic fluid and opening slightly, by a certain amount of shell 5, the working gap.

With full demagnetization of the core 4 gradient magnetic field and

5 the magnitude of the opening; the shells 5 are determined only by the magnetization of the core 7. With a further inflow of Ivshilkov in the current in the same direction (for opening the core 4 s

Q each pulse is more and more magnetized, the direction of its magnetization is opposite to the direction of magnetization of the core 7. Increasing the magnetization of the core 4 leads to a decrease in the gradient in the working gap, as part of the core of the core 7 closes at the ends and the gradient is determined only by the remaining part of the core of the 7 .. The regulator still continues to open. At full magnetization of the core 4, its field is equal to the field of the core 7 and will compensate it completely. The force of interaction of the field of cores 4 and 7 with ferromagnetic

5 liquid in the working gap almost disappears and only the force generated by the pressure of the working medium acts on the shell 5. The regulator opens completely. Further receipt of signals for opening does not disturb the state of the regulator, since the magnitude of induction of the magnetization of the core 4 remains unchanged and there is no gradient in the gap in the gap.

The regulator is closed by current pulses passed through the electromagnet 3 in the direction of the magnetization of the heart. Nick 4 agrees with the magnetization of the core 7. The order of operation of the regulator for closing is carried out by a vyov. demagnetization of the core 4 and its subsequent magnetization up to the saturation value, but at the same time the magnitude of the magnetic field gradient in the working gap steadily increases.

Thus, in the proposed controller, the end positions of the open and closed states are strictly fixed by making the core of two coaxially arranged parts. Moreover, there is no need for additional devices for determining the end positions of the regulator and stopping the signal supply.

Claims (2)

1.Nudler G.I. and others. Fundamentals of production automation. M., Higher School, 1976, p. 97, 101. 2. USSR author's certificate No. 630617, cl. G 05 O 7/06, 1976 (prototype).