JP3459930B2 - DC arc processing equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC arc machining apparatus such as a DC TIG welding machine, a DC plasma welding machine, and a fusing machine. More specifically, a high voltage is applied between the non-consumable electrode on the torch side and the base material. The present invention relates to a direct-current arc machining apparatus configured to supply and generate an arc between the two to start contactlessly.

[0002]

2. Description of the Related Art In a conventional DC arc machining apparatus of this type, a high voltage is supplied from a starting circuit at the same time that a starting operation signal (ON signal) for a starting switch attached to a torch is input to the starting circuit. A starting signal is sent to the supplying device, and a high voltage is supplied between the non-consumable electrode and the base material to start the starting.

[0003]

As described above, according to the conventional DC arc machining apparatus in which a high voltage is generated at the same time when the start switch is turned on, there is a problem if it is possible to immediately shift to a predetermined process such as welding after the start switch is turned on. However, if there is some time from the start operation of the start switch to the transition to the specified processing, the worker may get an electric shock because the high voltage continues to be output even in the no-load state during that time. , When an electric current flows through the human body due to such an electric shock,
There was a problem that would cause a shock shock.

Therefore, the present invention has been made in view of the above situation, and prevents the generation of a high voltage in a no-load state by adding a condition other than the operation of turning on the start switch to the start start operation. It is an object of the present invention to provide a DC arc machining device capable of ensuring safety by eliminating the risk of electric shock.

[0005]

In order to achieve the above object, the DC arc machining apparatus according to the invention of claim 1 of the present invention is usually connected to a non-consumable electrode on the torch side and a base material. A welding power supply for supplying a welding current during processing, a high voltage supply device connected to the non-consumable electrode and the base material for supplying a high voltage between the non-consumable electrode and the base material at the start of starting, the welding power supply and When an arc is generated between the non-consumable electrode and the base metal due to the high voltage supplied from the high voltage supply device and the high voltage supply device, a welding current is detected to detect the high voltage. While stopping the operation of the supply device, in the DC arc machining apparatus comprising a current detector for switching from the welding power source to the state of supplying the welding current for normal machining to the non-consumable electrode and the base metal,
The start-up circuit inputs a start-up switch ON operation signal and a short-circuit open detection signal by a detection means for detecting short-circuit open between the non-consumable electrode and the base material when the non-consumable electrode is once contacted and then separated from the base material. It is characterized in that it is configured to send a start signal as a condition.As an operating condition for starting the device, the non-consumable electrode on the torch side is temporarily contacted with the base material in addition to the operation of the start switch. The operation signal of the start switch is added by adding an operation such as separating after the operation, and the detection signal by the detection means for detecting the opening of the short circuit between the non-consumable electrode and the base material due to the additional operation through the torch. The start signal is sent from the start circuit only after the input condition is satisfied, and a high voltage is supplied between the non-consumable electrode and the base material from the high voltage supply device that receives the start signal. And arcing will be initiated activated during. Therefore, it is possible to avoid a situation in which a high voltage is generated in a no-load state where the start switch is simply turned on and operated, and an operator receives an electric shock and is shocked, and safety at the start of starting the device can be ensured. . And
When the welding current flows after the start of startup, the welding current is detected by the current detector, the operation of the high voltage supply device is stopped, and the welding current for normal processing from the welding power source to the non-consumable electrode and the base metal It will be supplied and automatically switched to normal processing.

The high voltage supply device may be a high voltage DC circuit for applying a high DC voltage between the non-consumable electrode and the base material, as described in claim 2. As described above, it may be any of the high-frequency generators that superimpose a high-frequency high voltage on the output of the welding power source,
It is desirable to use a DC high voltage circuit because it does not generate noise. Further, the DC processing device is a DC TIG
Like a welding machine, a DC plasma welding machine, a DC plasma fusing machine, etc., a high voltage is supplied between the non-consumable electrode on the torch side and the base metal only at the start of startup, and an arc is generated between the two without contact. It refers to the processing device to be activated.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing a configuration of a DC TIG welding machine applied as a DC processing apparatus according to the present invention. In FIG. 1, reference numeral 1 is a DC welding power source, the output end of which is a non-consumable electrode 3 on the torch 2 side. And is connected to the base material 4 to supply a predetermined welding current during normal welding. Reference numeral 5 denotes a DC high voltage circuit which is an example of a high voltage supply device, and the output end thereof is in series with the DC welding power source 1 and the non-consumable electrode 3 is provided.
Also, a high DC voltage is supplied between the non-consumable electrode 3 and the base material 4 at the start of activation by being connected to the base material 4. Reference numeral 6 is a block diode which blocks application of the DC high voltage supplied from the DC high voltage circuit 5 to the DC welding power source 1 side.

A starting circuit 7 sends a starting signal to the DC welding power source 1 and the DC high voltage circuit 5, and the output end of a starting switch 8 arranged in the vicinity of the torch 2 is It is connected. A current detector 9 detects a welding current when an arc is generated between the non-consumable electrode 3 and the base metal 4 due to the high DC voltage supplied from the high DC voltage circuit 5, and is normally used. The closed contact 9a is inserted on the input side of the DC high voltage circuit 5, and the operation of the DC high voltage circuit 5 is stopped by the opening operation of the normally closed contact 9a accompanying the detection of the welding current. The DC welding power source 1 is configured to self-maintain the supply of the normal welding current to the non-consumable electrode 3 and the base material 4.

Reference numeral 10 is a short circuit open detection circuit connected to the DC welding power source 1. When the non-consumable electrode 3 on the torch 2 side is once brought into contact with the base material 4 and then separated therefrom. The short circuit opening between the both 4 and 3 is detected by the voltage change of the detection power supply 11 connected to the non-consumable electrode 3, and is connected in series to the starting switch 8. Reference numeral 12 denotes a timer, which is connected to the output side of the short circuit open detection circuit 10 and starts a timed operation for a set time simultaneously with the output of the short circuit open detection signal, and the current detector 9 welds within the set time. The operation is stopped when the current is detected. Reference numeral 13 is a logical sum (OR) circuit, which is the current detector 9
The output signal of the OR circuit 13 and the operation signal of the start switch 8 are the AND condition. When the established signal is input to the starting circuit 7, the starting signal is sent from the starting circuit 7 to the DC high voltage circuit 5.

Next, the operation of the DC TIG welding machine having the above construction will be described with reference to the timing chart shown in FIG. When the start switch 8 is turned on and operated, an operation signal as shown in a of FIG. 2 is formed. However, since no signal is output from the OR circuit 13 in this state, the operation signal of FIG.
As indicated by f, the starting signal is not output from the starting circuit 7, and the welding machine is not started. When the operation switch 8 is turned on and operated, the non-consumable electrode 3 on the torch 2 side is once brought into contact with the base material 4 and then separated from the base material 4, thereby short-circuiting between the both 3 and 4, The voltage of the detection power source 11 connected to the non-consumable electrode 3 changes as shown in FIG. 2B, and the voltage change causes the non-consumable electrode 3 and the base material 4 to change.
The short circuit open detection signal as shown in FIG. 2C is output from the detection circuit 10 which detects the short circuit open.

Simultaneously with the output of the short circuit open detection signal c, the timer 12 starts the timed operation for the set time T, and the short circuit open detection signal c is input to one input terminal of the OR circuit 13 to cause the OR circuit 13 to operate. A signal as shown by e in FIG. 2 is output from 13 and a signal for which the AND condition of the output signal c and the operation signal a is satisfied is input to the starting circuit 7. Thus, the OR of the operation signal a of the start switch 8 and the short circuit open detection signal c for the base material 4 of the non-consumable electrode 3
A signal that satisfies an AND condition with the signal e output from the OR circuit 13 in response to the input to the circuit 13 is a start circuit 7.
2 to the DC high-voltage circuit 5, the DC high-voltage circuit 5 sends a start signal f to the DC high-voltage circuit 5 between the non-consumable electrode 3 and the base material 4 as shown in FIG. A DC high voltage is applied to the arc, which causes an arc to be generated between the two and starts the welding machine. That is, the non-consumable electrode 3 and the base material 4 are arc-started without contact.

When the welding current flows after the start of the start-up, the welding current is detected by the current detector 9 and the normally-closed contact 9a is opened, which causes the direct current as shown by g in FIG. Although the operation of the high voltage circuit 5 is stopped, a current detection signal as shown by h in FIG. 2 by the current detector 9 is input to the other input terminal of the OR circuit 13 to output a signal e from the OR circuit 13. Is continuously output, the supply of the normal welding current from the DC welding power source 1 to the non-consumable electrode 3 and the base material 4 is maintained by the start signal f from the start circuit 7 and the normal arc welding is automatically switched. To be The timer 12 stops operating and resets when the welding current is detected by the current detector 9 (point t in FIG. 2). However, if the arc start fails, the timer 12 is timed for a set time T. The operation is continued, and after the set time T has elapsed, the device activation is completely stopped.

FIG. 3 is a circuit diagram showing a configuration in which a high frequency generator 5A is used as a high voltage supply device for arc start in the DC TIG welding machine, and a point different from FIG. 1 is a DC welding power source. The high frequency voltage applied to the primary winding is boosted by the secondary winding by inserting the coupling coil 14 on the output side of 1, and the high frequency high voltage induced thereby is superimposed on the output of the DC welding power source 1. However, since the rest of the configuration is the same as that shown in FIG. 1, the corresponding parts are designated by the same reference numerals and their detailed description is omitted. Also,
The operation is similar to that of FIG.

In the above embodiment, the DC TIG is used.
Although the one applied to the welding machine has been described, when it is applied to the DC plasma welding machine or the DC plasma fusing machine, the base material 4 is applied to the positive side terminal of the DC welding power source 1 and the torch 2 is not applied to the negative side terminal. The consumable electrode 3 may be connected.

[0015]

As described above, according to the invention described in claims 1 to 3, as the operating condition for activating the apparatus, the non-consumable electrode on the torch side is temporarily set to the base material in addition to the operation of turning on the activation switch. Since it is added with an operation of separating after making contact, as in the past, a high voltage is generated in a no-load state just by turning on and operating the start switch, and the worker receives an electric shock and receives a shock shock, In addition, it is possible to avoid a situation in which the electric shock is generated, and it is possible to ensure the safety at the start of activation of this type of device. In particular, according to the second aspect of the invention, in addition to the effects as described above, since the high voltage supplied at the start of startup has no noise, the predetermined startup performance can be enhanced.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a configuration of a DC TIG welding machine applied as an embodiment of a DC arc processing apparatus according to the present invention.

FIG. 2 is a timing chart explaining the operation of the above DC TIG welding machine.

FIG. 3 is a circuit diagram showing a configuration of a DC TIG welding machine applied as another embodiment of the DC arc processing apparatus according to the present invention.

[Explanation of symbols]

1 DC welding power source 2 torch 3 Non-consumable electrode 4 base material 5 DC high voltage circuit (high voltage supply device) 5A high frequency generator (high voltage supply device) 7 Starting circuit 8 Start switch 9 Current detector 10 Short circuit open detection circuit 13 OR circuit

Claims (3)

(57) [Claims] 1. A welding power source that is connected to a non-consumable electrode on the torch side and a base material to supply a welding current during normal processing, and the non-consumable electrode that is connected to the non-consumable electrode and the base material at the start of activation. A high voltage supply device for supplying a high voltage between the base material and
A starting circuit that sends a starting signal to the welding power source and the high voltage supply device, and a welding current is detected when an arc occurs between the non-consumable electrode and the base metal due to the high voltage supplied from the high voltage supply device. In addition to stopping the operation of the high voltage supply device, a DC arc machining apparatus comprising a current detector for switching from the welding power source to the non-consumable electrode and a state for supplying a welding current for normal machining to the base metal. , The start-up circuit outputs a start-up switch ON operation signal and a short-circuit open detection signal by a detection means for detecting a short-circuit open between the non-consumable electrode and the base material when the non-consumable electrode is once contacted and then separated. A DC arc machining device, characterized in that it is configured to send a start signal as an input condition. 2. The DC arc machining apparatus according to claim 1, wherein the high voltage supply device is a DC high voltage circuit for applying a DC high voltage between the non-consumable electrode and the base material. 3. The DC arc machining apparatus according to claim 1, wherein the high voltage generator is a high frequency generator that superimposes a high frequency high voltage on the output of the welding power source.