SU575569A1 - Electrocodunctive strip velocity pickup - Google Patents

Description

one

The invention relates to the field of automation equipment and is intended for non-contact measurement of the speed of movement of various transport devices, and can also be used to measure the speed of two-A rolling sheet products from an electrically conductive material with constant parameters.

A known speed sensor for an electrically conductive strip, comprising permanent magnets with a core and signal coils, in the air gap between which the strip moves, induces an emf in the signal coils ij.

A transformer speed sensor is also known, which is a three-bar mag-wire with an excitation winding and a signal winding and a capacitor in the gap between which the electrically conductive band 2 moves. However, their sensitivity and accuracy are low, depending on the parameters of the electrically conductive field.

Also known is a speed meter comprising a magnetic core, an excitation winding and a measuring winding, in which

EMF of the transformation is induced and EMF arising when the strip 3j is moving. It provides for compensation of the parameters of the conductive strip. This is achieved by dividing the measuring winding into two coil systems, in one of which (x emf is induced by the strip movement. If the strip is parallel and the inductor plane is parallel, the ratio should not depend on the strip and gap parameters. The emf is equal transformation and movement. The disadvantage is its sensitivity to external magnetic fields.

The invention of the invention is an increase in the measurement accuracy and noise immunity of the speed sensor. This is achieved by the fact that the sensor cores are five-core with two excitation windings, one of KOTOffcix is installed on the middle rod, and the other covers the first winding two adjacent with the middle rod, and with two signal windings located on the neighboring with c) terminals.

FIG. 1 shows the sensor, side view; in fig. 2 is an electrical circuit for supplying an excitation winding and connecting a measuring winding.

The excitation winding 1 and measuring 2 are made of flat coils, stacked in the grooves of laminated cores 3 in two layers. The cores 3 form a gap through which the electrically conductive strip 4 passes, the speed of which is measured,

FIG. Figure 2 shows a diagram of the connection of the coils of the field windings 1 and the meter 2, which ensures the joint direction of the flows of the coils of both winding halves located on different cores. The plane of half of the windings located on the upper core is depicted conventionally rotated relative to its longitudinal axis by 180. The windings of both cores (fig. Are identical and represent a mirror image of each other. Each half of the sensor winding 1. located on the same core consists of two concentrically arranged large and small coils connected in series with each other and according to the magnetic flux. Half Measuring winding 2, located on the same core, consists of two identical coils located in grooves symmetrically with respect to the pole axis and connected in series and oppositely. Asterisks in FIG. 2 are marked by the beginning of the coils. For measuring the signal proportional to the speed of moving the strip, a dial device 5 of the magnetoelectric system is used, connected to the output of the circuit through a rectifying bridge 6.

FIG. 1 by F. denotes a pulsating magnetic flux caused by the excitation winding 1, and by F. a magnetic flux caused by currents induced in the conductor neck as it moves in the magnetic field of the sensor at a speed V. Through Φ in FIG. 1 is shown as magnetic, due to the EMF of a transformation induced in an electrically conductive strip 4 by a pulsed magnetic field of the excitation winding 1.

The excitation winding 1 is powered by a single-phase alternating current of industrial frequency from a source of stabilized voltage and creates a magnetic field in the gap of the pulsator. If there is no strip 4 in the gap, the voltage at the output of the circuit is zero, since the number of turns of large and small KBTyuieK of the excitation winding 1 is the same for irx sequential and consistent connection flow coupling between the windings of excitation 1 and measurement 2

equals zero. If there is a resting band in the gap, the resulting current in the gap also does not interlock with the coils of measurement winding 2. If there is a moving strip 4 in the gap, currents are induced in it and a portion of the magnetic flux Fu caused by the movement of the strip 4 in a magnetic field will close through both cores (Fig. 1), coupled with the coils of the measuring winding 2, in which the emf is proportional to the speed of movement of the strip 4.

Performing the measuring winding in the form of one group of coils mounted on the cores on both sides of the strip, using the positive quality of a known meter (obtaining the EMF of transformation and movement), allows to receive a signal at the output of the winding whose amplitude is proportional to the speed of movement of the electrically conductive strip with constant parameters. Installation Ser. The furnaces and the closure of magnetic fluxes along the direction of motion of the object being measured shortens the length of the circuit of the magnetic circuits, which has a positive effect on noise immunity, as well as on: the device can work at any distance from the band, which can also be from a ferromagnetic material. In the latter case, each core operates separately magnetically, and electrically it is simply the summation of signals from both parts of the measuring winding. The presence of an external alternating field and extraneous metallic objects will not cause the appearance of significant interference at the output of the measuring winding, since its coils on each core are switched on counter.

Claims (3)

1. USSR author's certificate No. 441512, cl. Q 01 P 3 / 5O, 1974. 2. The patent of Germany No. 1523245, cl. 42013/10, 1972. 3.Pivovarov L.V. Induction measures of linear velocity and length. Energy 1972. p. 12.