SU114829A1 - Displacement sensor - Google Patents

Description

A displacement sensor for machine tools with programmed control is known, which consists of a ruler with scale marks and a device that generates pulses, the number of which is proportional to the number of scale marks passed.

The described sensor is simpler to manufacture than the known one.

The sensor ruler is made of a non-magnetic material with a ferromagnetic coating, on which the harmonic oscillations of the maximum possible frequency on the order of 50 vibrations per 1 mm are applied by magnetic recording.

In the sensor device, which generates pulses, a reproducing modulating magnetic head is used to avoid the dependence of the pulse amplitude on the speed of movement.

The drawing shows a diagram of the displacement sensor for machine tools.

The main element of the described sensor is a ruler with scale marks on it, made of non-magnetic material in the form of bar 1, on which there is a thin layer of ferromagnetic coating 2. Harmonic vibrations are applied to this coating by magnetic recording.

The approximate resolution limit of the ruler is determined by the maximum possible frequency of recording harmonic vibrations in the order of 50 vibrations per 1 mm.

Using the fipn count of both positive and negative half-wave recordings, the resolution of the ruler is 100 half-periods by 1 mm, which corresponds to a division value of 10 microns.

The displacement sensor for machine tools with programmed control works when the speed of the working body varies widely (from fractions of a millimeter to tens and hundreds of millimeters

No. 114829

per second). Therefore, in a device that generates pulses from each half-period of the reproduced oscillation, a reproducing modulating magnetic head 3 with a bridge modulator circuit is provided. The magnetic flux reproduced from the tape of the core of such a head does not induce e. d. directly in the windings of the head, and modulates some high-frequency oscillation supplied to the head from the outside. Thus, the amplitude of the pulses does not depend on the speed of movement of the carrier during playback.

The magnetic head is excited by a high-frequency generator 4, which is five to ten times the maximum frequency of the signal.

The head output is an amplitude-modulated oscillation amplified by a resonant amplifier 5 and detected by an amplitude detector 6.

The high-frequency vibrations are filtered by filter 7; the useful signal is amplified by the low-frequency amplifier 8 and fed to the input of the full-wave rectifier 9. After the full-wave rectification, the fundamental frequency doubles, which makes it possible to double the resolution: i.e., separately calculate each half-period.

Further, the signal is applied to the limiter 10 and the differentiating chain 11 at the output of which pulses are generated, which are directed to the comparison circuit.

Under the diagrams of elements 5. 6, 7, 8, 5, 10, and / 7 of the sensor are given the characteristics of the serial conversion of pulses taken from the ruler into command signals.

Subject invention

Claims (1)

1. A displacement sensor for machine tools with software control, consisting of a ruler with scale marks and a device that generates pulses, the number of which is proportional to the number of scale marks passed, characterized in that, to simplify the manufacture of the sensor, its gauge is made of non-magnetic material a ferromagnetic coating on which magnetic recordings apply harmonic oscillations of the maximum possible frequency (about 50 vibrations per 1 mm). 2- Application in a pulse-forming arrangement of the sensor according to claim 1 of a reproducing modulation magnetic head, in order to avoid the dependence of the amplitude of the pulses on the speed of movement.