JPS5854913B2 - Jidoyousetsuki - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic welding machine that consumes little power and can stably supply welding wire.

In order to expand the range of action for welding work, two motors are used on the wire installation side and on the welding torch side, so that work can be performed even if the welding wire installation location and welding work area are about 10 meters apart. A method of performing welding work using a bush motor as the side motor and a pull motor as the torch side motor has become widely used.

Figure 1 shows an example of its configuration. 1 is a welding power source, 2 is a contact tip, 3 is a welding base material, 4 is a conduit tube for wire guidance between the pull motor and the tip 2, 5 is a feed roller, and 6 is a pull motor. , 7 is a conduit tube between the bush motor 9 and the pull motor 6, 8 is a feed roller, and 10 is a wire coil.

The wire is fed through the conduit tube 7.4 by two motors 6°9 and energized by the tip 2;
An arc is generated between the welding base material 3 and welding is automatically performed.

Fig. 2 shows a conventional example for controlling the rotation speed of two motors, where 23 is a motor power source, 11 is a switch element such as a thyristor that controls the motor rotation speed, and 12 is a switch element 11 that controls the rotation speed. a control unit providing a signal, 1
3 is a diode, and 14 is an impedance.

As an example, the bushing motor 9 is connected to the switch element 11.
The pull motor 6 is connected in series with the diode 13 and the impedance 14.

This connection method may be reversed depending on the case.

The relationship between the rotational speed and motor current (torque) of the two motors connected in this way is as shown in FIG.

The rotation speed of the pull motor 6 is controlled on the straight line QR determined by the impedance 14.

On the other hand, the push motor 9 has characteristics A1 to D1 depending on the control unit 12 and the switch element 11.

When the rotation speed of the bush motor 9 is given by A1, the pull motor 6 rotates at an operating point P1.

In other words, in order to synchronize the rotation speeds of the two motors,
One motor 9 is rotated at a constant speed, and the other motor 6 is connected in series with an impedance 14 of a large value, so that it rotates on an operating line with so-called drooping characteristics, in which the number of rotations decreases significantly as the motor load increases. It is customary to have

Although this conventional example has a relatively simple configuration, when the motor rotation speed is low, most of the power supplied from the motor power source 16 is consumed by the impedance 14, and when the motor rotation speed is large, the motor torque decreases. It had drawbacks.

The present invention is intended to improve the drawbacks of the conventional example with a simple configuration.

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 4, 15 is a motor power source, and the motor power source 15 is composed of a transformer 16 and a diode 17.

Depending on the type of housing and motor, only AC power, single-phase half-wave, full-wave, or three-phase half-wave/full-wave power supplies are used.

18 is connected in series with the pull motor 19 through impedance, one end is connected to one end of the motor power supply 15, the other end is connected to a switch element 20 such as a thyristor, and one end of the bush motor 21 connected to the other end of the motor power supply 15 is also connected to a switch. The switch element 20 is connected to another terminal of the motor power supply 15.

22 is a control unit that provides a control signal to the switch element 20.

The pull motor 19 has a high voltage A of the motor power supply 15.

The motor 21 is connected in series with the B, B' terminal, which has a low voltage value of the motor power supply 15, and the diode 11.
The other ends of the two motors are connected in parallel with a switch element 20.
connected in series with.

With this configuration, the bush motor 21 is controlled to rotate at a constant speed via the switch element 20 in response to a signal from the control unit 22, while the pull motor 19 is controlled to rotate at a constant speed via the impedance 18 and the switch element 20. Rotation control is performed using drooping characteristics such that the relationship between motor current and motor current is as shown in FIG.

As a result, the voltage applied to the pull motor 19 changes according to the rotation speed control of the bushing motor 21, so that even when the motor rotation speed is low, the power consumption due to the impedance 18, which has a low value, is small, and the pull motor rotation speed is large. In some cases, the applied voltage is so large that the motor torque does not decrease.

In Fig. 5, the solid line represents the characteristics of the pull motor 19,
The dotted line indicates the characteristics of the bushing motor 21.

In the above embodiment, the motor 19 is used as a pull motor and the motor 21 is used as a bush motor, but they may be reversed.

As explained above, the automatic welding machine of the present invention has a simple configuration and eliminates the drawbacks of conventional examples: increased power consumption due to impedance when the motor rotation speed is low and decrease in motor torque when the motor rotation speed is high. It has the advantage of being able to do a lot of things, and is of great industrial value.

[Brief explanation of drawings]

Figure 1 is a schematic configuration diagram of an automatic welding machine that automatically feeds and welds wire using two motors, and Figure 2 is a conventional electrical welding machine that controls the rotation speed of the two motors in Figure 1. Circuit diagram, Fig. 3 is a characteristic diagram of motor rotation speed and motor current in the conventional example, Fig. 4 is an electrical circuit diagram of the motor control circuit of the welding wire supply section of the automatic welding machine of the present invention, and Fig. 5 is a characteristic diagram of the motor control circuit of the welding wire supply section of the automatic welding machine of the present invention. FIG. 3 is a characteristic diagram showing the relationship between motor rotation speed and motor current in the automatic welding machine of the invention. 15...Power supply, 18...Impedance, 19°21...Motor, 20...
Switch element, 22...Control unit.

Claims (1)

[Claims] 1. The welding wire is configured to be automatically fed by two motors, a bush motor and a pull motor, and 2.
Using motor power supplies with two different voltage values, connect the motor in series to the one with the higher voltage value through an impedance, connect the motor directly to the one with the lower voltage value, and connect the other ends of the two motors. An automatic welding machine characterized in that it is connected to a motor power source via a switch element controlled by a control unit to control the rotational speed of the motor.