JPH0292460A - Method for adjusting wire extension - Google Patents

Abstract

PURPOSE:To omit adjusting work of wire extension before entering the next welding stage by retreating a torch by for arc length in the wire feed direction to cut an arc at the time of finishing welding in consumable electrode automatic arc welding. CONSTITUTION:A weld line WL is subjected to arc welding by an wire 2 by using the torch 1 and a bead B having a height H is being formed. Since an indentation C is generated at the welding finishing position, the movement of torch 1 is stopped and welding is continued till the indentation C is filled up and the torch 1 is raised as it is filled up to the height B of the bead B. When welding of the indentation C is finished, the torch 1 is pulled up by for arc length (l) at the time of finishing to cut the arc. By this method, work to adjust wire extension before entering the next welding stage is omitted and working efficiency is increased.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for adjusting the wire protrusion length in consumable electrode type automatic arc welding [Prior art] In consumable electrode type arc welding, the aiming position of the wire is important. During welding, it is necessary to determine the target position with an accuracy of about half the diameter used.

Therefore, in order to accurately determine the wire aiming position at the welding start point, a method was proposed by Tokko Sho that applies a voltage between the wire and the base metal and detects contact between the wire and the base metal. It is well known from the publication No. 56-5634.

In this conventional technology, if the protrusion length (extension) of the wire from the tip differs, the wire aiming position changes, and if the extension is extremely long, the nozzle will be removed from the base material before the wire tip contacts the base material. Not only will the torch come into contact with the base material, making it impossible to obtain a proper wire aiming position, but in some cases, the torch may collide with the base material and cause damage. Further, even if the extension is not extreme, if there is a difference in the predetermined protrusion length, this difference becomes an error in the wire aiming position.

Therefore, when attempting to accurately determine the wire aiming position using the above-mentioned conventional technology, after welding one welding line is completed and before starting welding of the next welding line, the extension must be moved to a predetermined length. need to be adjusted accordingly. Conventionally, methods for adjusting this extension to a predetermined length include mechanical cutting using a cutter, etc., as disclosed in Japanese Patent Publication No. 5930510, and Japanese Utility Model Publication No. 62-2733.
There is a method using an extension adjustment device disclosed in Japanese Patent No. 3.

[Problem to be solved by the invention]

In this way, when using a welding method in which a voltage is applied between the wire and the base metal and the wire target position is determined by detecting contact between the wire and the base metal, the extension must be adjusted to a predetermined length. is required, but for this purpose,
In addition to requiring special equipment for this purpose, the use of this type of equipment has the problem of interrupting a series of welding operations.

The present invention was made to solve this conventional problem, and the wire protrusion length is automatically adjusted at the end of welding, thereby making it possible to smoothly transition to the next welding process. The purpose is to provide a method of adjustment.

[Means to solve the problem]

In order to achieve the above object, the present invention is designed to cut the arc after the torch is retracted in the wire feeding direction by an amount equal to the amount of the arc when welding is completed.

[Effect]

In the present invention, since the torch is retracted by the amount of the arc at the end of welding, the wire extension is extended by the retracted amount, and can be automatically adjusted to the same length as the extension at the start of welding.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Figure 1 (al) is a well-known arc sensor in which the length of wire 2 is set to a predetermined length from the bottom welding line WL of the welding joint while performing welding under the welding conditions set for the downward welding joint. While maintaining the height of the torch l, i.e. the first
Figure (C1) shows a state in which the welding end position has been reached after continuing arc welding (main welding) at which the torch height reaches the predetermined wire length Lo before welding start. At the welding end position, , weld bead B shown in Figure 1 ta)
Since a depression (crater part) C is generated, stop the movement of the torch l while fishing on a boat, and under these welding conditions, the crater part C will be formed.
Crater treatment welding is carried out continuously, including the time it takes to fill the crater.

At this time, during the main welding, the arc sensor that makes the length of the wire 2 from the welding '41AWL to a predetermined length is kept in operation. The welding torch 1 rises in the direction of the arrow as the crater portion C is buried in the height H of the weld bead B due to melting of the wire 2 during crater treatment welding (FIG. 1(b)). Then, when the time for crater treatment welding is reached, the operation of the arc sensor is stopped. Therefore, in order to keep the length of the wire 2 sticking out by a predetermined length even if the arc is cut, in advance, the distance l between the tip of the wire and the bead surface where the arc was cut in the crater treatment welding performed this time is set, for example. , the value retrieved from the table stored in the control device of the welding equipment (
Pull up the torch ■) Pull up the torch 1 by α and then cut the arc. As a result, when the arc is cut, the length of the wire protruding from the welding torch l becomes a predetermined length.

Figure 2 shows another embodiment of the present invention, in which the arc is cut to a predetermined length after return welding is performed from the original welding end position. The trajectory of torch 1 is shown.

In the figure, Wl indicates the lower plate and W2 indicates the vertical plate. Welding is started by detecting the end of the vertical plate W2 using a starting edge detector, etc.
When the above-mentioned main welding (2) is completed, under the end welding conditions, move the torch 1 from the end of the standing plate W2 by a predetermined distance Ro to the rear from the end, and from this position, move the torch 1 to the rear side of the end in the width direction of the standing plate W2. The turning lso moves, and after stopping there for a predetermined time, it moves to the end side in the width direction by the above SO, and here,
After stopping for a predetermined time, the process shifts to return welding (2) in which the welding moves to the above-mentioned terminal end of the standing plate W2. The torch 1 moves a predetermined distance fiTo (for example, 10 mm) from the terminal end to the starting end side of the standing plate W2, stops, completes the return welding, and stops here for a predetermined time to perform crater treatment welding. During this crater processing, the extension of wire 2 is L (L+α=L
O).

During this crater treatment, as shown in Fig. 2, the X-axis and Y-axis of the welding robot are driven simultaneously to retract the torch 1 by a predetermined retraction amount α (= X + Y) in the wire feeding direction, and this evacuation Cut the arc when the operation is finished.

The retraction amount α is the thickness Hl of the fillet welded under welding conditions matching the specified length of welding in advance, and the arc length at the time of crater treatment is measured, and the value obtained by adding both values is calculated in this example. This is stored in the control device (computer) of the welding robot, and the specified leg length is searched for in the search field.

In this way, in this embodiment, the torch 1 is
After retracting by a predetermined retraction amount l, the arc is cut and welding is completed, so before this retraction operation, the extension that was L is
L+α=Lo. Therefore, when welding one vertical plate W2 is completed and welding the next vertical plate W2, there is no need to perform wire inching and cut the wire with a cutter to adjust the extension. When the welding is completed, the torch 1 can be directly moved to the welding start end side of the workpiece to be welded next, and the operation for setting the wire target position can be started.

〔Effect of the invention〕

As explained above, the present invention automatically adjusts the protruding length of the wire to a predetermined length when welding is completed, thereby eliminating the need to adjust the protruding length of the wire before starting the next welding process. This allows a series of welding to be performed more smoothly than in the past, increasing work efficiency.

[Brief explanation of drawings]

Figures 1 (a) to (C1 are diagrams showing the relationship between the torch, wire and bead for detailed explanation of the present invention;
FIG. 3 is a diagram showing a torch trajectory and a torch position for explaining another embodiment of the present invention. 1- Torch, 2- Wire, B- Bead, L...-Ak length. Figure 1 (a) (b) (C) Patent applicant Kobe Steel, Ltd.

Claims (3)

[Claims] (1) In consumable electrode type automatic arc welding, when welding is completed, the torch is retracted in the wire feeding direction by the length of the arc, and then the arc is cut. Wire protrusion length adjustment method searched from the correspondence table with arc length. (2) At the end of welding, the torch is retracted in the wire feeding direction by the bead height and arc length before cutting the arc, and the bead height and arc length are set according to various welding conditions set in advance. Wire protrusion length adjustment method searched from the correspondence table with bead height and arc length. (3) Claim 2 characterized in that the bead height is the bead height after return welding at the welding end in fillet welding.
The wire protrusion length adjustment method described.