JPS60238087A - Control device for wire extension in welding with consumable electrode - Google Patents

Abstract

PURPOSE:To provide a titled device which maintains specified wire extension and stabilizes a welding operation by converting the set value of welding current to a reference signal and maintaining the same change rate of the reference signal and the detection signal of the welding current when the welding current is adjusted. CONSTITUTION:This welding device executes welding with a consumable electrode by conducting welding current between a torch 2 which holds a wire 3 to be fed via a motor 4 and a driving roller 5 from a welding machine 1 thereby forming an arc. The set signal of the welding current set by a current regulator 13 for regulating the welding current in said device is inputted to a reference signal generating circuit 14 which outputs the reference signal based on said signal to a comparator 11. On the other hand, the welding current during welding is detected by a current detector 9 and the detection signal of the welding current is outputted to the comparator 11 via a characteristic conversion circuit 15. Said signal is compared with the above-mentioned reference signal and a deviation is determined. The torch 2 is controlled via an amplifier 12, a motor 7, a mechanism 6 for moving vertically the torch, etc. by said deviation signal so as to maintain the specified wire extension of the wire 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a protrusion length control device for maintaining a constant protrusion length of a welding device using a consumable curved electrode.

[Prior art]

FIG. 2 is a block diagram showing a protrusion length control device in conventional consumable electrode welding, in which (1) is a welding machine, (2) is a torch that holds a wire (3), and (4) is a drive roller (5).
) and feeds the wire (3). (6) is a torch up/down movement mechanism that moves the torch (2) further and down, (7) is a torch up/down motor that operates the torch up/up movement mechanism (6), and (8) is a Base metal, (9) is a current detector that detects the welding current between wire (3) supplied from welding machine (1) and base metal (8), and outputs a welding current detection signal, α1 is set during welding wire (
3) A reference signal preset according to the protrusion length,
Qη is a comparator that compares the reference signal α1 and the welding current detection signal output from the current detector (9) and outputs a deviation signal;
(6) amplifies the deviation signal output from the comparator Ql),
An amplifier drives the lower torch motor (7) according to the deviation signal.

In the overhang length control device configured as described above, the wire feeding motor (4) is driven, and while feeding the wire (3), welding current is applied from the welding machine (1) to the wire (3) and the base material (8).
) to generate an arc between the wire (3) and the base metal (8) to perform welding.

In this case, the surface of the base material (8) is not necessarily flat, and the surface of the base material (8) is not necessarily located horizontally. For this reason, the distance between the torch (2) and the base material (8) fluctuates I~, and the feeding speed of the wire (3) by the wire feeding motor (4) must be changed. Wire (3
) By changing the feed speed of the wire (3), the welding current becomes smaller as the protruding length of the wire (3) becomes longer, and conversely, as the protruding length of the wire (3) becomes shorter, the welding current becomes larger. If the welding current changes, the welding conditions will change, so it is necessary to keep the welding current constant. Therefore, the welding current is detected by the current detector (9), this welding current detection signal and the reference signal 01 are compared by the comparator 0, and the deviation signal output from the comparator α is sent via the amplifier 0'4. This input is input to the torch upper/lower motors (7), and by driving the torch upper/lower motors (7) and moving the position of the torch (2), the protrusion length is kept constant and the welding current is kept constant. .

In the conventional overhang length control device described above, it is not easy to set a reference signal according to the overhang length. If left as is, the protrusion length will change in response to the adjustment of the welding current.

Therefore, when changing the welding current setting value, use the reference signal 00.
also needs to change. However, it is not easy to change the reference signal 00 according to the set value of the welding current and the protrusion length, which causes problems such as a decrease in work efficiency and the occurrence of welding zones.

[Summary of the invention]

This invention was made for the purpose of improving the above-mentioned problems, and it converts the welding current set value into a reference signal, and furthermore, when the welding current is adjusted, the rate of change between the reference signal and the welding current detection signal is The present invention proposes a protrusion length control device for consumable curved electrode welding in which the reference signal is changed in accordance with the adjustment of the welding current so that the protrusion length remains constant.

[Embodiments of the invention]

FIG. 1 is a block diagram showing an embodiment of the invention.
In the figure, (1) to (9), (1η and (1) are the same as the conventional equipment described above. 0 pier is welding where electricity is applied from the welding machine (1) to the wire (3) and the base metal (8). A current regulator that adjusts the current, C14 is a reference signal generation circuit that converts the welding current setting signal output from the current regulator and outputs it as a reference signal, 0→ is the welding current detected by the current detector (9) This is a characteristic conversion circuit that converts and outputs it as a welding current detection signal.Reference signal generation circuit 04 and characteristic conversion circuit θ
The configuration is such that the rate of change of the output signal No. 9 when adjusting the welding current is the same.

In the protrusion length control device configured as described above, when the welding current is set to 100 A according to the protrusion length of the wire (3) with the current regulator set to 0, a welding current setting signal corresponding to this welding current is generated. is input to the reference signal generation circuit 04. The reference signal generating circuit 0→ outputs a reference signal based on the welding current setting signal to the comparator Ql). - 10,000, the welding current during welding is detected by the current detector (9), and the characteristic conversion circuit 6
The welding current detection signal is output to the comparator 0]) via →. The comparator αno compares the reference signal and the welding current detection signal, and controls the protrusion length to be constant based on this deviation signal.

When changing the welding current setting from, for example, 100 A to 20 OA while keeping the protrusion length constant by changing the welding conditions, the current regulator (2) is operated to change the welding current setting value. At this time, the reference signal generation circuit (I4) changes the reference signal at a constant rate of change in accordance with the changing set value of the welding current.

The characteristic conversion circuit a changes the welding current detection signal in response to the changing welding current at the same rate of change as the rate of change of the reference signal generation circuit α→. Therefore, even when the set value of the welding current is changed, there is no change in the deviation signal output from the comparator 01), and the protrusion length can be kept constant.

〔Effect of the invention〕

As explained above, this invention converts the set value of the welding current into a reference signal, so when the welding current is set according to the overhang length, a stable reference signal is automatically set, and the setting of the reference signal is This makes it easier to weld and further contributes to improving the quality of welding. In addition, when adjusting the welding current set value, since the rate of change of the reference signal and the welding current detection signal are the same, the predetermined protrusion length can always be kept constant, and the welding conditions can be adjusted. It is easy to change and has the effect of reducing welding man-hours.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the invention. FIG. 2 is a block diagram of a conventional protrusion length control device for consumable electrode welding. (1)...Welding machine, (2)...Torch, (3)...
・Wire, (4)...Wire feeding motor, (5)...
・Drive roller, (6)...Torch up/up movement mechanism, (
7)...Torch upper and lower motors, (8)...Base material, (
9)...Current detector, signal...reference signal, α■...
Comparator, 0'4...Amplifier, (11...Current regulator, θ→...Reference signal generation circuit, α→...Characteristic conversion circuit. In addition, the same symbols in each figure indicate the same - or A considerable portion is shown. Agent: Patent Attorney Sanro Kimura

Claims (1)

[Claims] In a welding device using a consumable curved electrode that moves the torch position up and down to maintain a constant protrusion length by comparing the detection signal of the welding current with a reference signal and keeping the welding current constant, the set value of the welding current is set as the reference signal. A protrusion length control device for consumable electrode welding, characterized in that when the welding current is adjusted, the rate of change of a reference signal and the rate of change of a welding current detection signal are the same.