SU761193A1 - Pickup for quality control and displacement value of parts being welded during contact butt welding - Google Patents

Description

The invention relates to the field of welding, can be used for resistance butt welding, welding with continuous flashing and heating with heating, as a feedback sensor 5 in automatic control systems of the welding cycle.

Known devices to control the mode of resistance butt welding [1], allow to determine the nature of the relative movements of the welded products

The known devices are complicated and not sufficiently accurate, since comprise gears having gaps ₁₅ which make an error in the measurement of the amount of movement of parts to be welded.

Also known sensor for controlling the amount of movement of the welded parts 20 when butt welding [2].

The emf in the signal winding of the sensor is induced due to its movement relative to the pulsating magnetic flux created by two coils of about ₂ 5 excitations, connected in a differential circuit. The emf induced in the signal winding depends linearly on the magnitude of the displacement. To 'change phase

2

EMF to reverse, ie, to increase the measurement range by 2 times, a special bias winding is used.

The specified sensor has drawbacks, in particular, the presence of a movable signal winding reduces the reliability of the sensor, complicates its design, increases the complexity. The use of bias winding requires additional costs of conductive and insulating materials, increases the size of the sensor, reduces economic performance.

The aim of the invention is to improve the measurement accuracy, increase the measurement range, increase reliability and efficiency of the sensor.

This goal is achieved due to the fact that the sensor is equipped with a steel ring fixedly mounted on the rod, the signal winding is placed directly on the housing from the side of said ring, and the excitation winding coils are connected in a two-wire parallel circuit with an adjustable resistor connected in series to one of the coils. The body is made of laminated steel sheets, isolated from each other and located in a plane perpendicular to the axis of the sensor.

761193

Fig. 1 shows the proposed sensor; in fig. 2 - connection diagram of the signal winding and excitation winding.

The sensor includes a housing 1, which acts as a magnetic core, which is laminated from forged electrical steel sheets, isolated from each other and located in a plane perpendicular to the sensor axis, steel core 2, excitation winding consisting of coils 3 and 4, fixed signal winding 5, steel ring 6, rigidly connected with stem 7, covers 8 and 9. Rod 7 is rigidly connected through a movable plate of the butt-welding machine to the product being welded (not shown in the drawings). In one of the circuits of the excitation winding included adjustable resistor 10.

There is an air gap 11 between the winding 5 ”and the ring 6.

The sensor works as follows.

When an alternating voltage is applied to the coils 3 and 4 connected to the two-wire parallel circuit of the excitation winding with the excitation winding of the resistor 10 connected in series to one of the circuits in the magnetic core, a pulsating magnetic flux appears that passes through the annular protrusion of the magnetic circuit, air gap 11, ring 6, core 2 and covers 8 and 9. The ring 6, rigidly connected through the rod 7 with the welded part, progressively moves along the annular protrusion. This creates a time-varying magnetic flux, which is the cause of the appearance in the fixed signal winding of an EMF proportional to the part of the flux coupled to the signal winding. When moving the steel ring 6 from the middle position at the output of the winding 5, an EMF appears, the value of which linearly depends on the amount of movement. For two displacements of the same magnitude but different in sign, the values of the emf are equal in magnitude and are in antiphase. The phase change to the opposite is achieved by the inclusion of one of the coils of the excitation winding of the resistor 10 in the circuit, thereby increasing the measurement range of the magnitude of the displacement by 2 times. Thus

Thus, the dependence of the induced EMF of the winding 5 on the magnitude of the movement of the welded product is linear over the entire range.

The application of the proposed sensor in the butt-welding machines as a feedback sensor in the regulator by the welding cycle and for measuring the amount of movement will provide an accurate signal about the amount of movement of the parts to be welded during the melting and draft. Performing the signal winding fixed and in one layer eliminates the most time-consuming operation - uniform winding of this winding on the frame. Reduced sensor cost. The elimination of the winding bias reduces the complexity, cost, size. The range of controlled movements is from 0 to 100 mm, the measurement accuracy is ± 0.02 mm, and the small error from temperature fluctuations.

F.

Claims (2)

formula of invention 1. Sensor control and measurement of the displacement of the welded parts during resistance butt welding, comprising a housing, a rod, a signal winding and an excitation winding, made in the form of two coils, characterized in that, in order to improve measurement accuracy, increase the measurement range, increase reliability and Efficiency, the sensor is provided with a steel ring fixed on the rod, the signal winding is placed directly on the housing from the side of the ring, and the field winding coils are connected via a two-wire pair series-parallel circuit with a circuit included in one of the coils varistor. 2. Sensor π. 1, characterized in that the body is made of laminated steel sheets, isolated from each other and located in a plane perpendicular to the axis of the sensor.