JPS643586Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an arc welding machine that performs welding while feeding a filler wire to a welding part.

In TIG welding and plasma welding using non-consumable electrodes, the joint portion of the workpiece is heated and melted by an arc, and a filler wire is fed to the weld portion to obtain the necessary weld metal. Conventionally, the feed rate of the filler wire has been determined based on the welding current, mainly to control the heat input to the welding part. On the other hand, in order to obtain a high-quality weld, so-called pulse welding is performed by repeatedly changing the welding current high and low. In this case, when feeding the filler wire, controlling the feeding speed in synchronization with the welding current is an important requirement in order to obtain a uniform weld. .

However, in order to perform this kind of pulse welding, it is necessary to prepare a dedicated pulse power source configured so that the output current changes periodically, and such a power source has a lower power consumption than a normal welding power source. It's expensive. Furthermore, there are few devices in which the period, pulse width, pulse peak value, etc. of the pulse current can be arbitrarily adjusted, and even if a dedicated power source is used, the range of application thereof is narrow.

In contrast, the present invention proposes that most commonly used welding power sources are thyristor- or transistor-type power sources that set a reference signal and control the output current to match this signal. To facilitate this, a remote regulator, commonly called a remote control box, is installed at a distance from the main unit of the power supply, and is connected to the main unit by a cable, and the output current receives the signal from this remote regulator. It can be easily adjusted by the signal supplied to the input terminal, and as mentioned above, in welding using pulsed current, changes in filler wire feeding speed and changes in welding current are approximately the same or both. It is an important requirement that the As a result of consideration, by changing the feed speed of the filler wire and using the feed speed of the filler wire as a reference, a signal corresponding to the change in the feed speed signal is used as the welding current setting signal. The present invention proposes a pulse arc welding machine in which filler wire feeding speed and changes in welding current always match or have a specific relationship without using a dedicated pulse power source.

FIG. 1 shows an embodiment of the present invention. The figure shows an embodiment of the present invention in TIG welding using a tungsten electrode, where 1 is a welding torch, 2 is a workpiece, 3 is a filler wire, and a feeding electric motor 4
The material is fed to the welding part through a guide 6 by a feed roll 5 driven by a feed roll 5 driven by a feed roll 5 driven by a feed roll 5 driven by 7 is a feeding motor control circuit, 8 is an output setting circuit, which includes setting devices 81 and 82, diodes D1 and D2, a repeatable timer 83 that can set ON time and OFF time, respectively, and power supplies 84 and 85. It consists of Reference numeral 9 denotes a manual switch that starts a timer 83 to change the filler wire feeding speed, and is attached to the welding torch 1, for example. A welding power source 10 supplies power between the welding torch 1 and the workpiece 2 from terminals A and B to ignite an arc, and obtains power from a commercial power source (not shown). This welding power source 10 is a known welding power source with approximately constant current characteristics that outputs a current corresponding to the reference voltage based on the voltage input to terminals C and D,
Further, the motor control circuit 7 is a known motor control circuit that rotates the motor 4 at a speed corresponding to the reference voltage based on the voltage input to the terminals E and F, and these are all of the type that feeds back the output. However, if there is sufficient capacity, there is no need to perform feedback.

In the embodiment of FIG. 1, while the manual switch 9 is not closed, the motor control circuit 7 is switched to the first setter 8 selected by the normally open contact 83a of the timer 83.
The electric motor 4 is rotated at a speed determined by 1 to feed the filler wire 3. In contrast, welding power source 10
Like the motor control circuit 7, outputs a current determined according to the output of the first setting device 81. Next, when the manual switch 9 is closed, the timer 83 is started and the normally open contacts 83b and 83a are alternately opened and closed at a set period. Here, the first setting device 8
The feeding speed of the filler wire determined by 1 is made small, the speed determined by the second setting device 82 is made large, and the welding current determined by the output signal of the first setting device 81 is made a relatively small current. If the welding current determined by the output signal of the second setting device 82 is set to a large current, the welding current will change in response to changes in the filler metal feeding speed, and the welding power source 10 can be used exclusively for this purpose. As a result, pulse welding in which the feed speed of the filler wire and the welding current are synchronized can be performed even if the pulse welding power source is not the same.

In the embodiment shown in FIG. 1, the setting device is switched by the contact of the timer 83 for switching the filler wire feeding speed, and the output signal of this setting device is simultaneously supplied to the motor control circuit 7 and the welding power source 10. However, with the filler wire, there is a slight time delay from when the setting signal changes until the speed actually changes due to the mechanical delay of the feeding device. Therefore, when it is desirable that the true filler wire feeding speed and welding current change simultaneously, a delay circuit is provided between the output setting circuit 8 and the welding power source 10 to delay the change in the output of the welding power source. Bye. Further, the filler wire feeding speed may be set at high speed and low speed, or may be stopped and fed. Furthermore, the setting circuit for changing the filler wire feeding speed is not limited to the combination of the manual switch and timer shown in Fig. 1, and three or more setting devices may be provided to set them in a specific order. Therefore, it may be programmed to select them sequentially. Of course, the present invention can also be applied to a device in which there is only one setting device and the operator arbitrarily adjusts it to change the filler wire continuously. Furthermore, the setting signals for the motor control circuit 7 and the welding power source 10 may be changes in resistance values, except for the other power source 85 which is a voltage signal, as shown in the example of FIG.

As described above, in this invention, the output current setting device of the welding power source is switched according to the selection of the setting device, so the output current can be remotely controlled without having to prepare a dedicated pulse welding power source. Pulse welding using filler wire can be performed using a general-purpose welding power source that can perform Of course, the period, peak value, and pulse width of the pulse current at this time can be controlled arbitrarily. In addition, since the feed speed of the filler wire is used as a reference and a commensurate welding current is supplied, the feed rate of the filler wire is determined based on the change in the conventional welding current. Unlike this method, welding can be performed by adjusting the feed rate of the filler wire, which directly affects the amount of welding, according to changes in the groove shape of the welding part or changes in the required amount of extra metal, making the work extremely easy. It has many effects, such as:

[Brief explanation of the drawing]

FIG. 1 is a connection diagram showing an embodiment of the present invention. 1... Welding torch, 2... Work to be welded, 3... Filler wire, 4... Filler wire feeding motor, 7...
Motor control circuit, 8... Output setting circuit, 9... Manual switch, 10... Welding power source, 81, 82...
Setting device.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In an arc welding machine that performs welding by lighting an arc between a non-consumable electrode and a workpiece and feeding filler wire to the welding part, an output setting circuit and , comprising a filler wire feeding device that receives the output of the setting circuit as an input and feeds the filler wire at a speed according to the input signal, and a welding power source that outputs a current according to the output signal of the setting circuit. arc welding machine. 2 The setting circuit is a setting device that outputs two signals for feeding and stopping the filler wire at a predetermined speed, and the welding power source outputs a high current when feeding the filler wire and a low current when stopping the filler wire. The arc welding machine according to claim 1 of the utility model registration claim, which is a power source that outputs. 3. The setting circuit is a setting device that outputs two high and low signals for feeding the filler wire at high and low speeds, and the welding power source changes the filler wire feeding speed to high and low speeds. The arc welding machine according to claim 1, which is a power source that outputs high current and low current correspondingly. 4. The setting circuit is a circuit that repeatedly selects the plurality of feed speed setting devices in a predetermined order by a plurality of setting devices using a presettable timer. The arc welding machine according to any one of Item 3. 5. The setting circuit is operated manually by an operator. Claim 1 of the Utility Model Registration Claim
The arc welding machine according to any one of items 1 to 3. 6. The welding power source is a power source whose output current is remotely adjustable and has a remote adjustment signal input terminal, and the output signal of the setting circuit is divided and supplied to the remote adjustment signal input terminal. The arc welding machine according to any one of items 1 to 5.