JPS60108182A - Power source device for flash butt welding device - Google Patents

Abstract

PURPOSE:To enable fine adjustment over a wide range of an output voltage and omission of an auto-transformer by changing over the plural taps provided to the tertiary winding on the high voltage side of a power transformer connected to a welding transformer. CONSTITUTION:A power source device is constituted of a power transformer 1, thyristors 2, 3 for flashing in fore and post periods, a welding transformer 6, an electrode 7 and a tap changer 40 inserted to the plural taps 1B of a tertiary winding 1A on the high voltage side of the transformer 1. The changer 40 is used for changing over the taps 1B to change over the voltage. Since the number of the taps 1B can be increased, the fine adjustment of the output voltage is made possible over a wide range and in addition the auto-transformer and the taps of the transformer 6 in the prior are omitted.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention applies a predetermined voltage between a pair of members to be welded facing each other with a predetermined gap therebetween, and then brings the two-wave welding members closer to each other, thereby reducing the contact point. The present invention relates to a flash butt welding device that generates a flash, heats and melts double-wave welding members by the flash, and applies necessary pressure between the two-wave welding members in a direction in which they are crimped together. In this type of flash butt welding equipment, the first flash voltage raises the temperature of the workpiece to be welded at room temperature to a high temperature, and the temperature of the workpiece to be welded rises to a predetermined temperature.
A fine flash is produced to prepare the edges of the molten metal, leading to the final upset welding (welding in which two parts are butted together, pressure is applied, and then welding current is applied to raise the temperature by resistance heat generation and pressure is applied). The present invention relates to a power supply device that generates a late flash voltage.

[°Conventional technology]

Conventionally, the flash voltage in the power supply device of this type of flash butt welding equipment needs to generate flash gold as continuously as possible, and for this reason, in order to minimize the entire period of voltage "0", the voltage is set to 't' of the sine wave. Since it is designed to be energized, it is not possible to use a phase control method as a means of adjusting the voltage, and the material of the workpiece to be welded and the
Depending on the plate thickness and width, both the fc early flash voltage and the late fc flash voltage are applied.

Figure 1 shows a power supply circuit when an autotransformer is used as the tap switching method described above, and Figure 2 shows a power supply circuit when a welding transformer is used as the tap switching method described above. In FIGS. 1 and 2, (1) is a power transformer, (2) is a group of thyristors for early flash, (3) is a group of thyristors for late flash, and (4) is a cod 7' of autotransformer (5). (5A)
, or a tap changer provided at the tap (<SA) of the welding transformer (6), (7) is an electrode, and the above-mentioned No. 1
In the autotransformer system, when the capacity is several thousand KVAO, such as when welding steel, etc.,
Power transformer (1) and auto transformer (5)
Not only do two units have to be installed, but the number of windings in the autotransformer (5) is small, so it is not possible to finely adjust the secondary voltage, making it difficult to obtain the optimal voltage. 4) Since the current flowing through VC is large, there is a drawback that it is structurally difficult to change taps in automatic control performed by a computer, for example. In addition, in the welding transformer system shown in Figure 2 above, it is necessary to provide a large number of taps to switch between them, which inevitably results in a large welding transformer.
By reducing impedance, especially inductance, a narrow flash is produced, which has the disadvantage that it is not possible to improve welding performance (fine adjustment of voltage,
The problem of the large current flowing through the tap changer is the same as that of the autotransformer system described above.

[Summary of the invention]

This invention was made with attention to this point, and it is possible to solve the above-mentioned drawbacks by providing a plurality of taps on the high-voltage sixth winding provided in the power transformer and inserting a tap changer into the taps. It is something that you are trying to remove.

[Embodiments of the invention]

That is, FIG. 5 shows one embodiment of the present invention, in which (1) IDT source lance, (2) thyristor for early flash, (3) thyristor for late flash,
(6) is the bath-connected transformer, (7) is the electrode, and (4t) is the multiple taps (IB) of the high voltage side tertiary winding (1A) of the power transformer (1). -, the voltage can be switched.

〔Effect of the invention〕

The power supply device for flat welding and butt welding processes of the present invention includes the 6th winding on the high voltage side of the power transformer (1) as described above.
Multiple taps (IB) on moat (1A) Since it is easy to increase the number of taps by 2, not only can fine adjustment of the output voltage be performed over a wide range, but also the taps of the conventional auto transformer (5) and welding transformer (6) can be omitted. This not only contributes to cost reduction, but also enables retroactive transformers (
A tap changer (4 (
Since the tap changer (40K) flows less current, it has the effect of making it extremely easy to change taps under automatic control using a computer, for example.

In addition, in the above-mentioned embodiment, a case was described in which a tag changer (4G') was used to switch the tap (IB), but the present invention is not necessarily limited to this.
It is certainly possible to obtain similar effects by using other switching devices such as contactors.

[Brief explanation of drawings]

1 and 2 are circuit diagrams showing a power supply device in a conventional flash bat m-contact device, and FIG. 6 is a circuit diagram showing an embodiment of the present invention. In the figure, (1) is a power transformer, (IA) is a thyristor for Pi high/high voltage side 6, (3) is a thyristor for late flash,
(6) is a welding transformer, (7) is an electrode, and 01Jl is a tap changer. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent: Sanro Kimura, Patent Attorney, Figure 3, Letter of Amendment (Spontaneous), March 131, 1980.''Tlj+i'l' Ii Mr. Director, 1, Matters f'l, No. J, Special Application Sho. 58=216227
No. 2, Name of the invention Power supply device for flash butt welding equipment 3, Supplementary name 4, Substitute 8

Claims (1)

[Claims] (A plurality of taps are provided on the high-voltage side tertiary winding of a power transformer connected to a welding transformer that applies a predetermined voltage to one electrode, and the voltage is adjusted by switching these taps. (2) The flash butt welding device according to claim 1, characterized in that a tap changer is inserted into each tap of the sixth winding on the high voltage side. (3) The power supply device for a flash butt welding apparatus according to claim 1, wherein the welding transformer includes an early flash thyristor and a latter flash thyristor connected in parallel. .