SU1404804A1 - Contact variable-capacitance transducer for checking thickness of wire insulation - Google Patents

Abstract

The invention relates to a measurement technique and is aimed at increasing the reliability of monitoring the thickness of the insulation of wires by increasing the number of control zones, as well as increasing the contact capacitance sensor by increasing the slip friction between its electrode and the cone surface. 1 ;; wired wire for rolling friction. Electrode 1 of a capacitive sensor is made in Bn, i.e. UHXlplMi Research Institute and the outer diameter of which (t the cross-sectional area of the coil is chosen in such a way that the controlled one) d 2 enters the inner hole with some tension to ensure 11 good contact between the spring wires and the wire surface. In the npo iecce measurement, the coils roll along the insulation surface of the test wire, the thickness of which affects the capacitance ng1 between the sensor electrode 1 and the current-carrying conductor 5 wire. 2 i.i. i (Л с: N $ О N 00 Figure 1

Description

The invention relates to a measurement technique and can be used to control the thickness of the insulation of wires during their manufacture.

The aim of the invention is to increase the reliability of control and durability of a contact capacitive sensor to control the insulation thickness of wires by increasing the number of points of contact with the surface of the test wire in its circumferential direction, as well as by replacing the slip friction between the sensor electrode and the surface of the test wire for rolling friction .

FIG. 1 schematically shows the constructive performance of a contact capacitive sensor; in fig. 2 is a view A of FIG. one.

The contact capacitive sensor for monitoring the thickness of the insulation of the wires contains an electrode 1, made in the form of a helical spring, coiled into a torus. The hole in the torus must correspond to the diameter of the test wire 2, which must enter into this hole with some tension to ensure reliable contact between the surface of the test wire and the coils of the spring electrode 1. The coils of this electrode are also in contact with the conductive surface 3 of the current collecting device 4, between which and the current-carrying core 5 of the monitored wire 2 is connected a secondary measuring transducer 6, which provides a measurement of the capacitance between them, depending on the thickness of the insulation in a controlled area of the wire 2.

Contact capacitive sensor operates as follows.

When the monitored wire 2 is pulled through the electrode 1 of the capacitive sensor, the turns of the coil spring roll along the insulation surface of the monitored wire and simultaneously press against the conductive surface 3 of the current collector 4. Depending on the insulation thickness, the capacitance value is measured in the monitored wire. A secondary converter 6.

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0 c 0

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Since the points of contact of the coil spring coils and the wire insulation are placed at any moment in the same plane of the section of the monitored wire, the result of the capacitance measurement is recorded directly in this section. Due to the fact that the coils of the coil spring during the monitoring process roll along the surface of the insulation continuously and their contact points move successively both along the generator of the test wire and around its circumference, this ensures continuity of control over the insulation thickness.

The cross-sectional shape of the turns of the helical spring can be any, for example in the form of a circle, ellipse, square or rectangle. The number of coils of the spring affects the number of contact points in the circumferential direction; therefore, an increase in the contact points leads to an increase in the reliability of the control of the insulation thickness of the wires. It should be noted that the cross-sectional dimensions of the coils of the spring and its diameter affect the spring stiffness and, therefore, the strain value of the insulation being monitored, and an increase in the diameter of the spring provides an increase in the life of the sensor by reducing the amount of wear on the contacting spring surface.

These considerations must be taken into account when designing contact capacitive sensors of this type. The electrodes of the capacitive sensor, made in the form of a coil spring coiled into a torus, are simple to manufacture and allow an average value of the change in the insulation thickness to be determined with sufficiently high accuracy in a controlled portion of the wire length.

Claims (1)

Invention Formula A contact capacitive sensor for monitoring the thickness of the insulation of wires containing an electrode to contact with a controlled wire during the measurement process, characterized in that, in order to increase the reliability of control and durability of the sensor, the electrode is made in the form of a helical spring coiled into a torus.