SU859079A1 - Method of seam resistance welding - Google Patents

Description

(54) METHOD OF SEAM CONTACT WELDING

 - one

The invention relates to contact welding of metal Majaox thicknesses on alternating current and can be used in the manufacture of industrial products, electronic equipment and instrument-making, for example, when sealing them into metal glass and metal-ceramic cases using the method of seam contact welding.

The known method of junction welding is carried out using one-way or non-polyfarmed frequencies of an industrial network, separated by pauses of welding current and formed synchronously with each half-period of phase voltage of network 11.

The disadvantage of the known method is the limited possibility of increasing the welding speed and the process productivity associated with it while reducing the heat-affected zone from the effects of forming heat sources during the welding process,.

There is also known a method of seam contact welding based on the impulse frequency impulse frequency (30; 0-2500 Hz), in which the welding pulses and the duration of the pauses between the welding pulses are controlled synchronously with the increased frequency pulses, and the current pulse series is pulsed. Forming by changing the transformation ratio of the welding transformer {2.

The disadvantage of this method is the need to use a special high-frequency generator for welding machines that implement this method.

Closest to the proposed. is a method of seam resistance welding based on the frequency of the industrial network and the formation of energy pulses with regulation in amplitude and duration by varying the angles of switching on and off the welding current in each phase voltage loop 20, and adjusting the durations of the pulse series and pauses according to the number of phase periods of the phase voltage wives 13).

25 A disadvantage of the known method is the low productivity of the welding process, which is explained by the fact that. that the amplitude and length of the welding pulses were generated by the EO by adjusting the angles of switching on and off the welding current only in one phase of the voltage of the industrial network.

The purpose of the invention is to increase the productivity of the welding process.

This goal is achieved by the fact that the amplitude and duration of current pulses are controlled in each of the three phase voltages of the industrial network.

At the same time, the formation of durations of a series of energy pulses and pauses between pulses is performed according to the number of half periods of each of the three phase voltages of the industrial network.

Figure 1 shows the shape of the welding pulses during continuous welding; in FIG. 2, the Same, with the presence of pauses) in FIG. 3, a series of welding pulses with the maximum duration in FIG. 4 - the same, with the increasing form of the pulse envelope.

The implementation of the method is carried out with the use of a single-phase welding transformer, in the primary winding of which a three-phase uncorrected voltage is applied via synchronized power switches in each phase. The latter can consist of parallel-connected powerful transistors, for example, four KT809

PRI me R 1. Comparison of welding speed with single pulses of 2.5 ms duration with front and fall control (Fig. 1) and with pulses of each half period of single phase voltage with front control in each half period on a welding layout installations with single-phase formation of welding pulses. The layout is equipped with a mechanism for moving the housings with adjustable speed and power transistor switches. Sealed case type 401.14-5 coated Nickel-Gold. Cover thickness 0.1 mm, base 1, 6,

The point overlap factor is applied at 0.5, and by varying the welding current and welding speed, the weld seams are equally strong. Under the conditions of strength and tightness of the joints, equal to the joint by single-phase welding at a speed of 10 mm / s, the welding speed of the proposed method can be increased to 24 mm / s. This happens due to a threefold increase in the frequency of welding pulses and a certain decrease in the length of the welding points.

Example 2. On the same layout and cases as in example 1, the maximum temperature is determined at a distance of 0.7-1 mm from the weld when welding with three three-period single-phase current and a series of three pulses according to the proposed method with the difference between off and on angles S 60 ° C and with an increasing amplitude envelope (Fig. 4). The duration of the pulse train is chosen to be equal to the pause duration in both cases (30 ms in single-phase welding and .10 ms in the proposed method). J A thermocouple of copper-constant wires and a diameter of 0.1 mm is fixed in place of the last lead of the 1PO housing to the long-side welding course.

The measured average (of ten meter) rim temperature of the base of the body when welding with three half-cycles of single-phase current is 133 ° C, when welding with a series of three pulses of the proposed method 107 ° C, which indicates a decrease in the heat-affected zone when using welding frequency pulses of the industrial network with the strengthening of the front and the decline in each half-period.

0 Increasing the welding speed improves the performance of the process and equipment.

The method causes the welding equipment to be simplified due to SEO3 ability of the three-phase network to a single-phase transformer.

Claims (3)

Invention Formula . The method of seam contact welding based on the use of industrial network frequency and the formation of energy pulses with regulation in amplitude and duration by varying the angles of switching on and off the welding current in each half-phase voltage, and adjusting the duration of the series of pulses and pauses by the number of half cycles phase voltage, tl and h and y and so that, in order to increase the productivity of the welding process, the amplitude and duration of the current pulses are controlled in each of three phase voltage frequency, industrial network. 2. The method according to claim 1, characterized in that the formation of the durations of a series of energy impulses and pauses between them is made according to the number of half-cycles of each of the three phase voltages of the industrial network frequency, Information sources. taking into account during the examination 1. Paton B.E. and Lebedev V.K. Electrical equipment for contact welding. M., engineering, 1969, pp.81-85. 2. Copyright C1 certificate of the USSR According to Application No. 2132398 / 25-27, cl. In 23 K 11/24, 1975. 3. USSR author's certificate per application 2522424/21, cl. H 03 K 17/60, 1977.