JP2005034903A - Arc welder using battery as electric source - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve an energy-saving, a resource-saving, a miniaturization and reduction in weight of a battery type arc welder and to improve work efficiency of welding work by applying the newest semiconductor technique to the battery type arc welder thereby realizing the high efficiency thereof. <P>SOLUTION: The arc welder uses an intermittent control circuit for the control of arc current. The arc welder uses an insulation type intermittent control circuit for converting DC source used for the charging of the battery and for auxiliary electric source from a commercial electric source. That is, the control circuit drives a power switch circuit by a rectangular wave of high frequency of a variable duty ratio with the use of electric source supplied from the battery (48V). The power switch circuit amplifies the power of output of the control circuit. The power-amplified rectangular current is smoothed with a smoothing circuit and made to DC and outputted, and voltage and current of the output are fedback to the control circuit and compared with a signal voltage in the setting circuit to output the set voltage and current. Further, the overheat protection of the semi-conductor, the lowered voltage protection of the battery, etc., are detected through the control circuit, so that equipment is safely operated. The charging circuit of the battery enables a driving frequency of an insulating transformer to be 50 KHz by applying the intermittent control circuit. Thus, the miniaturization and the reduction in weight of the insulating transformer can be achieved and further, the characteristics, such as high accurate fixed voltage and fixed current are obtained by the duty ratio control, and the battery is safely and perfectly charged. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

Detailed Description of the Invention

The present invention is for reducing the size, weight and efficiency of a mobile arc welder (battery welder) used at a construction site or the like.

For arc welding work in places where power supply conditions are not good, such as construction sites, or places where commercial power is not installed, a method of operating a generator with an internal combustion engine and performing arc welding work with that power source and using a battery as a power source The current welding battery welding machine structure (circuit), which uses arc resistance, uses a resistor to control the arc current, and the arc current is controlled by switching between two or three resistance values. For example, if the arc voltage of arc welding is 25V, the arc current is 100A, and the battery voltage is 48V, the resistance value is 0.23Ω and the power loss is 2300W. The arc power is 2500W. Loss of the current and fine adjustment of the current adjustment is impossible.Of course, if the battery voltage decreases, the arc current also decreases and stable melting is achieved. Work becomes impossible, so a large-capacity battery is required, and the charger that charges the battery is a direct power transformer (50/60 Hz) that is rectified and charged as required by the battery characteristics. The life of the battery may be shortened because it cannot be performed. Naturally, the transformer is large and heavy because it is for commercial power supply. Therefore, the conventional one is large, heavy and low in efficiency.

Problems to be solved by the invention

(B) Improve battery welding machine efficiency and make fine adjustments to the arc current, and downsize the battery.
(B) The battery charger attached to the battery welder will be miniaturized and the battery will be charged with the required charging characteristics to extend the battery life and improve efficiency.

Means for solving the problem

(B) Replace the element used for current limiting and current adjustment used in arc welding with a simple passive element resistor used in the prior art, and replace it with an intermittent control circuit using a semiconductor as an active element. (B) If the charger is also used with an intermittent control circuit using semiconductors and the intermittent frequency is about 50 KHz, both the volume and weight of the insulation transformer are commercially available. By performing time ratio control of voltage and current that is several tenths of the frequency (50/60 Hz), it is possible to supply voltage and current for high-precision control required by the battery. Battery life can be extended.

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

In FIG. 1, a control circuit in which DC power is supplied from a battery (48V) power source to a power switching circuit and a control circuit. Supplying current to the output, storing electromagnetic energy in the smoothing choke coil at that time, and releasing the energy when the power switch circuit is OFF. As a result, the high frequency voltage of the rectangular wave developed by ON / OFF of the power switch circuit The amount of current can be adjusted in the range of (0-100%) by adjusting the ON / OFF time ratio of the power switch circuit, which can be converted into DC current, and this adjustment is controlled by the control circuit. Adjustable voltage of 5V is possible with small variable resistor, and output voltage, output power If ask fed back to the control circuit constant voltage, operates as a constant current source, that matter is output currents even drops the battery voltage can be performed stable welding becomes constant.

In FIG. 2, a commercial power supply (100 V, 50/60 Hz) is rectified by a rectifier circuit via an inrush current blocking circuit and a noise prevention circuit to become a DC power supply (≈130 V), which is supplied to the power switch circuit and the control circuit. Outputs a rectangular wave of about 50 KHz and drives a power switch circuit to grow a high frequency power source of 50 KHz.
The primary winding of the isolation transformer is driven by this high-frequency power supply to insulate from the secondary winding, and the transformed high-frequency power supply is rectified and smoothed to become a DC power supply to charge the battery and an auxiliary power supply. Because it becomes a high-efficiency constant voltage, constant current, and power source to control the / OFF time ratio, it can supply the high-accuracy voltage and current required by the battery. Can be very small and light,

The invention's effect

In the present invention, as shown in FIG. 1, a conventional battery-type arc welder current control element using a resistor is replaced with an intermittent control circuit with a variable time ratio. The battery can be miniaturized with fine adjustments.

(B) In the present invention, as described in the embodiment, FIG. 2, the conventional battery welding machine is driving the insulation transformer of the charger with the commercial power supply (50/60 Hz). By switching to a circuit and driving with a high-frequency rectangular wave (50 KHz), the insulation transformer can be made smaller and lighter, and the constant voltage and constant current characteristics become highly accurate and the charging characteristics required by the battery can be obtained. it can.

The above-mentioned two things can make the casing of the welding machine small and light, and both transportation and work can be done by one person in the past, and can greatly contribute to energy and resource saving.

Block diagram of the arc current controller of a battery-type arc welder Block diagram of the battery charging part of a battery-type arc welder Conventional technology block diagram

Claims (2)

    Arc welder using intermittent control circuit to control arc current     An arc welding machine that uses an insulated intermittent control circuit to convert a DC power source used for battery charging and auxiliary power from a commercial power source

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