JPH05123864A - Nonconsumable electrode arc welding machine - Google Patents

Abstract

PURPOSE:To provide the nonconsumable electrode arc welding machine capable of always obtaining a uniform weld bead width without changing the weld bead width even if an arc length is changed. CONSTITUTION:The nonconsumable electrode arc welding machine is constituted of a pulse current output circuit 1, an arc voltage detection circuit 5 to detect the arc voltage of an arc 3 generated between a nonconsumable electrode 2 and base metals 4 by the output from the pulse current output circuit 1, an arc voltage proportional signal generation circuit 6 to input an output signal of the arc voltage detection circuit 5 and a pulse frequency setting circuit 7 to input an output signal of the arc voltage proportional signal generation circuit 6, and an output signal of the pulse frequency setting circuit 7 is inputted to the pulse current output circuit 1 to control output frequency of the pulse current output circuit 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-consumable electrode arc welder capable of controlling the frequency of a pulse current as a welding current and performing high-quality welding.

[0002]

2. Description of the Related Art An example of a conventional non-consumable electrode arc welding machine is shown in FIG. In FIG. 4, 1 is a pulse current output circuit,
2 is a non-consumable electrode, 3 is an arc, 4 is a base metal, 7 is a pulse frequency setting circuit, and 8 is a pulse frequency adjuster.

In the conventional non-consumable electrode arc welding machine shown in FIG. 4, the pulse frequency adjuster 8 arbitrarily adjusts the pulse frequency, and the pulse frequency setting circuit 7 sets the pulse frequency according to the adjustment of the pulse frequency adjuster 8. , The pulse current of the pulse frequency set by the pulse frequency setting circuit 7 is output from the pulse current output circuit 1, and the non-consumable electrode 2
The arc 3 was generated between the base material 4 and the base material 4 to perform welding.

[0004]

Generally, the arc voltage and the arc length are in a proportional relationship, and the arc voltage increases as the arc length increases. Also, FIGS. 5 (a) and 5 (b)
As shown in (1), since the angle θ _{0 at} which the arc spreads does not change even if the arc length increases, the arc length l ₀ increases and l ₁
Then, the area S ₀ where the arc 3 contacts the base material 4 becomes S ₁ , and S ₀ <S ₁ (1) holds. Therefore, when the arc length fluctuates, the welding bead width also fluctuates, and there is a problem that a uniform welding bead width cannot be obtained.

The present invention is intended to solve the above problems, and provides a non-consumable electrode arc welder in which the welding bead width does not fluctuate even if the arc length fluctuates, and a uniform welding bead width is always obtained. With the goal.

[0006]

To achieve the above object, a non-consumable electrode arc welding machine according to the present invention includes a pulse current output circuit and a non-consumable electrode and a base metal between the pulse current output circuit and an output from the pulse current output circuit. An arc voltage detection circuit that detects the arc voltage of the generated arc, an arc voltage proportional signal generation circuit that inputs the output signal of the arc voltage detection circuit, and a pulse frequency setting that inputs the output signal of the arc voltage proportional signal generation circuit Circuit, and the output signal of the pulse frequency setting circuit is input to the pulse current output circuit to control the frequency of the output of the pulse current output circuit.

[0007]

As shown in FIGS. 2 (a) and 2 (b), when a pulse current is used as the arc current, it is known that the focus of the arc improves as the pulse frequency increases.
That is, when the arc length l ₂ is constant, the frequency in the case of FIG. 2 (a) is f, the frequency in the case of FIG. 2 (b) is f ', and f <f' (2) When f'is increased as described above, the spread angle θ of the arc becomes smaller and becomes θ ', and accordingly, the area where the arc 3 in FIG. If the area in contact with the material 4 is S ', then S>S' (3). Therefore, as shown in FIGS. 3A and 3B, the arc length l ₃ of FIG. 3A is l ₄ shown in FIG. 3B.
When the relationship of l ₃ <l ₄ (4) is satisfied, that is, when the arc length is increased from l ₃ to l ₄ , the frequency f ₁ in FIG. (B)
If the frequency f ₂ is made higher than f ₁ in proportion to the arc voltage as in the relationship of f ₁ <f ₂ (5) with the frequency f ₂ of the arc of FIG. Spread θ ₁ and Fig. 3
By setting the relationship of the arc spread θ _{2 in} (b) to θ ₁ > θ ₂ (6), the area S ₂ where the arc 3 contacts the base material 4 can be kept constant. Therefore, when the arc length fluctuates, the fluctuation of the arc voltage due to the fluctuation of the arc length is detected, and the pulse frequency is controlled by the arc voltage to control the area where the arc 3 contacts the base material 4 to be constant. The welding bead width can be kept constant.

[0008]

FIG. 1 shows a circuit configuration of an embodiment of a non-consumable electrode arc welding machine of the present invention. In FIG. 1, the same parts as those in FIG. 4 are designated by the same reference numerals, and the description will be omitted to explain different points. In FIG. 1, 5 is an arc voltage detection circuit, 6
Is an arc voltage proportional signal generating circuit, and other parts are the same as those of the conventional example shown in FIG.

In FIG. 1, an arc 3 is generated between the non-consumable electrode 2 and the base material 4 by the pulse current output from the pulse current output circuit 1, and the voltage of the arc 3 is detected by the arc voltage detection circuit 5. The output signal of the arc voltage detection circuit 5 is input to the arc voltage proportional signal generation circuit 6, and the arc voltage proportional signal generation circuit 6 generates a signal for changing the pulse frequency in proportion to the change of the arc voltage. The output signal of the arc voltage proportional signal generation circuit 6 is input to the pulse frequency setting circuit 7, the output of the pulse frequency setting circuit 7 is input to the pulse current output circuit 1, and the pulse current output circuit 1 changes as the arc length changes. It outputs a pulse current with a pulse frequency that changes in proportion to the changing arc voltage.

As a result, even if the arc length changes during welding, the arc voltage that changes with the change in arc length is detected, the pulse frequency of the pulse current changes, and the spread of the arc is kept constant. The bead width is kept constant.

[0011]

As is apparent from the above description, according to the present invention, even if the arc length changes in the solution, the arc voltage which changes with the change of the arc length is detected by the arc voltage detection circuit, Since the pulse frequency is changed in proportion to the voltage, the spread of the arc decreases with the increase of the pulse frequency of the pulse current and also increases with the decrease of the pulse frequency of the pulse current, and the arc contacts the base metal. The area is always kept constant, and it is possible to realize a non-consumable electrode arc welder in which the width of the welding bead does not change even if the arc length changes during welding, which greatly contributes to uniform welding quality.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a non-consumable electrode arc welder of the present invention.

FIG. 2 (a) is an enlarged view in the vicinity of the arc showing the relationship between the pulse frequency and the spread of the arc when the arc frequency is kept constant and the pulse frequency is lowered, and FIG. 2 (b) shows the arc length kept constant and the pulse frequency increased. Enlarged view near the arc showing the relationship between pulse frequency and arc spread in the case

FIG. 3 (a) is an enlarged view of the vicinity of the arc when the pulse frequency is lowered when the arc length is reduced and the area where the arc contacts the base metal is kept constant. Enlarged view of the vicinity of the arc when the pulse frequency is increased and the area where the arc contacts the base metal is kept constant

FIG. 4 is a block diagram of a conventional non-consumable electrode arc welding machine.

FIG. 5 (a) is an enlarged view in the vicinity of the arc showing the relationship between the arc length and the area where the arc contacts the base metal when the pulse frequency is kept constant and the arc length is reduced. Enlarged view near the arc showing the relationship between the arc length and the area where the arc contacts the base metal when the arc length is increased.

[Explanation of symbols]

 1 pulse current output circuit 2 non-consumable electrode (electrode) 3 arc 4 base material 5 arc voltage detection circuit 6 arc voltage proportional signal generation circuit 7 pulse frequency setting circuit

Claims (1)

[Claims] 1. A pulse current output circuit, an arc voltage detection circuit for detecting an arc voltage of an arc generated between a non-consumable electrode and a base material by an output from the pulse current output circuit, and an output of the arc voltage detection circuit. It is composed of an arc voltage proportional signal generation circuit that inputs a signal and a pulse frequency setting circuit that inputs the output signal of the arc voltage proportional signal generation circuit, and the output signal of the pulse frequency setting circuit is input to the pulse current output circuit. A non-consumable electrode arc welder designed to control the output frequency of the pulse current output circuit.