JPS60238085A - Control device for wire extension in welding with consumable electrode - Google Patents

Abstract

PURPOSE:To provide a titled device which maintains easily a specific wire extension and stabilizes welding conditions by the constitution in which the position of a torch is moved and the welding current during welding is controlled on the basis of the welding current after arc starting flowing according to the set wire extension. CONSTITUTION:The welding current after arc starting which flows according to the wire extension of the wire 3 set preliminarily to meet welding conditions is detected by a current detector 9 and the detection signal of the stable welding current after lapse of the specified time controlled by a timing limiting circuit 14 right after arc starting is stored and held in a storage circuit 13 in the welding device which conducts the welding current between a torch 2 holding the wire 3 fed via a driving roller 5 by a wire feed motor 4 and base metals 8 and executes welding using consumable electrode. The stored and stabilized signal is determined as a reference signal. The welding current to be detected during welding is compared with said reference signal by a comparator 11 and a signal is emitted so that the difference therebetween is made zero. The torch 2 is thereby vertically moved via an amplifier 12, a motor 7, a moving mechanism 6, etc. by which the wire extension is maintained constant.

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 electrode.

[Prior art]

FIG. 4 is a block diagram showing a conventional protrusion length control device for consumable electrode welding, in which (1) is a welding machine, (2) is a torch that holds the 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 position of torch (2) up and down (the force is the torch up/down movement mechanism (
6) is the torch upper and lower motor that operates, (8) is the base material,
(9) is a current detector that detects the welding current between the wire (3) and the base metal (8) supplied from the welding machine (1) and outputs a welding current detection signal; OI is the wire ( 3
) is the reference signal set in advance according to the protrusion length, α.
9 is a comparator that compares the reference signal (II) with the welding current detection signal output from the current detector (9) and outputs a deviation signal;
a3 amplifies the deviation signal output from the comparator (11),
It is an amplifier that drives the torch upper and lower motors (power) 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, nor is it necessarily located horizontally. Therefore, the distance between the torch (2) and the base material (8) changes, and the wire (
3) The feed speed must be changed. wire (3)
By changing the feed speed, 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. In this way, when the welding current changes by i, the welding conditions 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 α0 are compared by the comparator 01), and the deviation signal output from the comparator 01) is sent to the torch via the amplifier 02. - By inputting force to the lower motor (force) and driving the torch upper and lower motors (7) to move the position of the torch (2), the protrusion length is kept constant and the welding current is kept constant.

However, in the conventional protrusion length control device described above, it is necessary to set a reference signal each time the protrusion length is determined in accordance with welding conditions, and there is a problem in that setting the reference signal is not easy.

[Summary of the invention]

This invention was made with the purpose of improving this problem, and detects the welding current after the arc starts flowing according to a preset protrusion length, stabilizes this welding current detection signal, stores it, and uses it as a standard. consumable electrode welding, which compares this reference signal with the current detection signal during welding and moves the torch position up and down to keep the protrusion length constant so that the welding current remains constant during welding. This paper proposes a protrusion length control device for.

[Embodiments of the invention]

FIG. 1 is a block diagram showing one embodiment of the present invention,
In the figure, (1) to (9), 01) and Oz indicate the same parts as the above-mentioned conventional device. 0:1 stores and retains the welding current detection signal detected by the current detector (9) after the arc starts;
The memory circuit (a4) that outputs the stored signal as a reference signal is a time limit circuit that inputs the welding current detection signal after a certain period of time immediately after the start of the arc to the memory circuit (+3+).

In the protrusion length control device for consumable electrode welding configured as described above, the protrusion length of the wire (3) that matches the welding conditions is determined before welding starts, and the welding current is transferred from the welding machine (1) to the wire (3). The arc is started between the wire (3) and the base metal (8). This welding current is detected by a current detector (9), and a welding current detection signal is output from the current detector (9). A welding current detection signal after a certain period of time has passed immediately after the start of the arc is input to the memory circuit (13) by the time limit circuit Oa, and is stored in memory. In other words, since the welding current immediately after the start of the arc fluctuates greatly, if the welding current detection signal immediately after the start of the arc is memorized and used as a reference signal, the setting of the protrusion length will deviate. The welding current detection signal, which has stabilized over time, is used as the reference signal. Therefore, the memory circuit 03) can output a stable reference signal according to the set protrusion length. A comparator (tl) compares this reference signal with the welding current detection signal during welding.
The protrusion length can be kept constant by driving the torch upper and lower motors based on the deviation signal output from the comparator αB.

Therefore, by setting a predetermined protrusion length before starting welding, the protrusion length during welding can be automatically kept constant based on the predetermined protrusion length.

FIG. 2 is a block diagram showing another embodiment of the present invention. !19 is provided.

Integrating circuit 09 integrates the welding current detection signal output from the current detector (9) immediately after the start of the arc for a certain period of time, corrects the fluctuation of the welding current immediately after starting the arc, and stores the stable signal in memory circuit 0□□□ Enter. Therefore, the memory circuit (1
From 3), it is possible to output a stable reference signal according to the protrusion length set in advance before the start of welding.

FIG. 6 is a block diagram showing a sixth embodiment of the invention. The sixth embodiment shown in the figure is a current detector (9)
In this configuration, a first integrating circuit (151) is provided between the current detector (9) and the comparator (11), and a second integrating circuit ae is provided between the current detector (9) and the comparator (11).

The first integrating circuit (+51) performs exactly the same function as the integrating circuit 0!19 shown in the second embodiment, and the second integrating circuit (16) outputs the output from the current detector (9). The welding current detection signal during welding is integrated, current fluctuations are corrected, and the resultant signal is output to the comparator 01). According to this embodiment, the reference signal and welding current detection signal input to the comparator 01) are both integrated by the integrating circuits (+5) and (16), so even if the welding current has a pulse waveform, the protrusion length is Control can be performed stably.

〔Effect of the invention〕

As explained above, in this invention, the reference signal for determining the protrusion length during welding is determined based on the preset protrusion length, so if the protrusion length that matches the welding conditions is determined, the protrusion length during welding is automatically determined. The protrusion length can be controlled to be constant, the reference signal can be easily set, and at the same time, welding can be performed under stable welding conditions, which greatly contributes to improving the quality of welding.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of this invention, FIG. 2 is a block diagram showing a second embodiment of this invention, FIG. 6 is a block diagram showing a third embodiment of this invention, and FIG. 4 is a block diagram showing a third embodiment of this invention. The figure is a block diagram of a protrusion length control device for conventional consumable electrode welding. (1)... Welding tl, (21... Torch, (3)...
・・Wire, (4) ・・Wire feeding motor, (5)・
... Drive roller, (6) ... Torch up/down movement mechanism,
(7)...Torch upper and lower motors, (8)...Base material,
(9)...Current detector, 00)...Reference signal, 01
)...Comparator, (13...Amplifier, 0...Storage circuit, (I4)...Time limit circuit, 051゜(16)...
・Integrator circuit. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Patent Attorney Sanro Kimura

Claims (1)

[Claims] In a welding device using a consumable electrode, the welding current detection signal during welding is compared with a reference signal, and the torch position is moved up and down to maintain a constant protrusion length so that the welding current remains constant. A protrusion length control device for consumable electrode welding, which detects a welding current after starting an arc that flows according to the protrusion length, stabilizes this welding current detection signal, stores it, and uses it as a reference signal.