JPH10137948A - Power unit of composite spot welding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an advantage of both an inverter AC type and a capacitor discharge type and to facilitate selection and handling of operation. SOLUTION: The unit is provided with one each of a supply power source 1, an inverter conversion circuit 4, a capacitor discharge circuit 5, a centralized controller 7 and a transformer 8. Power supply is distributed from the supply power source 1 to the inverter convertion circuit 4 and the capacitor discharge circuit 5, by selecting either of the inverter conversion circuit 4 and the capacitor discharge circuit 5 as specified by the centerized controller 7, is outputted to the transformer 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for a combined spot welder of an inverter AC type and a capacitor discharge type of a spot welder.

[0002]

2. Description of the Related Art Conventionally, as a spot welding machine, it has been considered to select either an inverter AC type or a capacitor discharge type having different welding power sources according to the purpose of welding.

[0003] The inverter AC type is characterized in that a single-phase or three-phase power supply is rectified and converted into a high-frequency AC, so that it is easy to control an energizing time and a welding current as an inverter function. However, as compared with the capacitor discharge method, there is a problem that the nugget formation, indentation, and burning due to a rise in temperature are inferior due to a longer rise during energization.

On the other hand, the capacitor discharge type rectifies and charges a single-phase or three-phase power supply and discharges it by switching. It is possible to flow a large current in a short time, and to use an inverter AC. Compared to the formula, it is characterized in that it is difficult to indent and burn when forming a nugget due to a rise in temperature or energization time. However, since control (energy conversion) is performed by discharging with a capacitor, there is a problem that it is difficult to strictly control the energization time or the welding current.

[0005]

However, the conventional spot welding machine has the following problems in order to select a welding machine having a different welding power source according to the purpose of welding.

In order to perform welding with a different welding machine every time the material to be welded is different, care must be taken not to make a mistake in selecting a welding machine. In addition, since each welding machine is configured to limit the products that can be processed and to perform welding control taking advantage of the features of each welding machine, control is complicated as a single welding machine for all products. And the handling operation becomes troublesome. In addition, there is a problem in that the equipment cost imposed by the power source of each welding machine becomes a considerable burden.

[0007] An object of the present invention is to solve the above-mentioned problems by providing different welding power sources depending on the purpose of welding.
It is an object of the present invention to provide a power supply device for a composite spot welding machine which can easily select a welding method between an AC inverter and a capacitor discharge type and has the advantages of an inverter AC type and a capacitor discharge type.

[0008]

To achieve the above object, the present invention provides a power supply, an inverter conversion circuit,
A capacitor discharging circuit, a centralized control device and a transformer, each of which distributes power from the power supply to the inverter converting circuit and the capacitor discharging circuit, and which is designated by the centralized control device. A power supply device for a composite spot welding machine characterized in that only one of an inverter converting circuit and a capacitor discharging circuit is selected and output to the transformer.

Therefore, the output current converters of the inverter AC type and the capacitor discharge type are integrated into one control device,
In addition, by using one transformer in common, it is easy to select a welding method between an inverter AC type and a capacitor discharge type having different welding power sources, and has the advantages of the inverter AC type and the capacitor discharge type.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, the power supply device of the composite spot welding machine includes a power supply 1, a rectifier circuit 2, power distribution devices 3 and 6,
Inverter conversion circuit 4 and capacitor discharge circuit 5
And the central control device 7 and the transformer 8, one each except for the power distribution devices 3 and 6.

In the three-phase or single-phase power supply 1, a port specified by the central control device 7 is opened by the power distribution device 3 via the rectifier circuit 2. At the same time as the command to the power distribution device 3,
Inverter conversion circuit 4 or capacitor discharge circuit 5
In response, the central controller 7 transmits and receives welding data,
The transmitted data is relayed through the power distribution device 6, output to the primary side of the transformer 8, and spot-welded on the secondary side. The power distribution devices 3 and 6 are synchronized with each other.

The centralized control device 7 has welding data of an inverter AC type and welding data of a capacitor discharge type in advance.
The common elements of the output current converters (not shown) for the inverter AC system and the capacitor discharge system are centralized by inputting data artificially and managed by centralized control.

Therefore, in the spot welding machine according to the present invention, when the power distribution devices 3 and 6 are activated, either the inverter conversion circuit 4 or the capacitor discharge circuit 5 is instructed by the output current conversion unit of the central control device 7. This is a composite spot welding machine composed of a power supply unit having the advantages of each of the inverter AC type and capacitor discharge type welding machines, with the switching being performed and the transformer 8 being shared.

The present invention is not limited to the above embodiment, but can be embodied in other modes by making appropriate design changes.

[0016]

As is clear from the above description, the power supply device of the composite spot welding machine according to the present invention distributes power from the power supply to the inverter conversion circuit and the capacitor discharge circuit, and concentrates the power supply. Inverter specified by the controller
Either the inverter conversion circuit or the capacitor discharge circuit is selected and output to the transformer, so that the problems of the prior art can be easily solved.
Combined with the advantages of the capacitor discharge type, its selection is easy and its handling operation is easy.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power supply 3, 6 Power distribution device 4 Inverter conversion circuit 5 Capacitor discharge circuit 7 Centralized control device 8 Transformer

Claims (1)

[Claims] A power supply, an inverter conversion circuit, a capacitor discharge circuit, a centralized control device and a transformer are provided one by one, and the inverter conversion circuit and the capacitor discharge circuit are provided from the supply source. A composite circuit characterized in that power is supplied to a circuit, and only one of the inverter conversion circuit and the capacitor discharge circuit designated by the central control device is selected and output to the transformer. Power supply for spot welding machine.