SU142438A1 - Device for contactless continuous monitoring of the diameter of thin wires - Google Patents

Description

Devices for contactless continuous control of the diameter of thin wires are known, based on the capacitive principle, however, these devices do not provide sufficient measurement accuracy and ease of operation.

In the proposed device, the capacitive sensor is made in the form of a metal surface with an insulating coating applied on it, on which a controlled wire moves.

The described device consists of a capacitive sensor, a meter for small capacitances and a wire pulling mechanism. The wire is pulled through a capacitive sensor, in the cylindrical case of which there is a gap, cut by an electric-spark method. An invar core is placed in the same case, and thin paper is used as an insulator, held by friction force. Instead of paper, you can apply a layer of ceramics applied by spraying. In the sensor, the wire forms one electrode, and the core - the second. The entire meter for small containers, except for the power supply, is mounted in a metal casing and consists of a trimming capacitor used for calibration and adjustment, and a galvanometer is used as an indicator, which can be replaced with a recorder with a measurement limit of O-500 µV.

FIG. 1 shows a block diagram of a meter of small quantities; in fig. 2 - capacitive sensor; in fig. 3 - position of the monitored wire in the sensor.

In the wire drawing mechanism, the wire is last rewound from the spool to the roll, a passage along the guide wheel through a capacitive sensor. The wire rewinding speed is controlled by an autotransformer that changes the speed of rotation of the motor.

The small-scale meter (Fig. 1) consists of a master oscillator 1, a cathode repeater 2, an amplifier 5, a phase-shifting quadripole 4, a phase detector 5, an indicator 6, a working sensor 7, a tuning capacitor 8 and a power source 9.

V g

II

if

,