JPH0631447A - Method for controlling filler wire feed position of non-consumable electrode type arc welding - Google Patents

Abstract

PURPOSE:To prevent the generation of weld defects by controlling the filler wire feed position of non-consumable electrode type arc welding in accordance with the periodically detected voltages between the filler wire and base metals. CONSTITUTION:The voltages between the filler wire and the base metals are periodically detected and the feed position of the filler wire is corrected and controlled in accordance with the results thereof in the non-consumable electrode type arc welding which executes welding by feeding the filler wire while controlling an arc length by constant arc voltage control. The correction rate of the feed position is so set that the correction rate in the descending direction of the filler wire is larger than the correction rate in the ascending direction. As a result, the welding is executed in the state of bringing the front end of the filler work into adequate contact with a molten pool, by which the generation of the defect in the weld zone is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filler wire feed position control method in non-consumable electrode type arc welding.

[0002]

2. Description of the Related Art Conventionally, AVC (Auto Voltage Control)
Japanese Patent Laid-Open Publication No. 62-179870 discloses a technique for correcting the filler wire insertion position by detecting the variation of the arc voltage depending on the filler wire and the insertion position by TIG (constant arc voltage control).

[0003]

However, in the prior art, when using the hot wire TIG method of Joule heating in which the filler wire must always be in contact with the molten pool, the degree of tangent cannot be detected or corrected. However, there is a problem in that the insertion position of the filler wire is set too low in order to surely bring the filler wire into contact with the molten pool, and the filler wire picks up the solidified molten portion to cause a defect.

In the above-mentioned prior art, since the movement amount (position correction amount) of the filler wire is always the same both in the ascending direction and the descending direction, the target position of the filler wire is adjusted to an appropriate position with respect to the molten pool. It was difficult to do.

The present invention is intended to solve such a problem, and it is possible to carry out welding in a state where the tip of the filler wire is appropriately brought into contact with the molten pool to prevent the occurrence of defects in the welded portion. It is an object of the present invention to provide a filler wire feed position control method for non-consumable electrode type arc welding.

[0006]

In order to achieve the above object, a filler wire feed position control method for non-consumable electrode type arc welding according to the present invention is to control the arc length by constant arc voltage control to control the filler wire. During non-consumable electrode type arc welding that feeds and welds, the voltage between the filler wire and the base metal is periodically detected, and the feed position of the filler wire is corrected and controlled based on the detection result. The correction amount of the feeding position of the filler wire is
The correction amount in the descending direction is set to be larger than the correction amount in the ascending direction of the filler wire. Further, the correction amount may be defined by time.

[0007]

According to the filler wire feed position control method for non-consumable electrode type arc welding of the present invention described above, the feed position of the filler wire is determined based on the periodic detection result of the voltage between the filler wire and the base metal. When performing correction / control, by setting the correction amount in the descending direction larger than the correction amount in the ascending direction of the filler wire, the filler wire tip is placed in the molten pool without setting the filler wire insertion position too downward. Welding can be done with proper contact.

Further, by defining the position correction amount of the filler wire by time, the correction amount can be freely adjusted.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A filler wire feeding position control method for non-consumable electrode type arc welding as an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a flow chart for explaining the procedure, and FIG. It is a block diagram which shows the structure of the non-consumable electrode type arc welding apparatus to which the method is applied.

First, the structure of the non-consumable electrode type arc welding apparatus to which the present method is applied will be described with reference to FIG. 2. In FIG. 2, 1 is a non-consumable electrode, 2 is a filler wire, and 3 is a filler wire.
Is a base material, 4 is a voltage detection circuit for periodically detecting the voltage between the filler wire 2 and the base material 3, and 5 is a set voltage (detected by the voltage detection circuit 4 set by the detection level setting device 6 (For example, 2.5 V), a short circuit determination circuit that determines a short circuit state when the detected voltage becomes equal to or lower than a set voltage, and a rise command U
On the other hand, when it is determined that the short-circuit state is not established, the descending command D is output.

Further, 7 is a filler wire position adjusting motor for adjusting the tip position of the filler wire 2 by moving up and down, and 7a is a motor drive circuit for driving this motor 7.
Reference numeral 8 is a motor drive cycle setter for setting the drive cycle T1 of the motor 7, and 9 is a descending operation time T set by a descending operation time setting device 10 in response to a descending command D from the short circuit determination circuit 5.
2 is a descending operation command circuit for outputting a descending operation command to the motor driving circuit 7a, and 11 is a motor driving circuit 7a for the ascending operation time T3 set by the ascending operation time setter 12 in response to the ascending command U from the short circuit determination circuit 5. In the ascending operation command circuit that outputs the ascending operation command to, in the present embodiment, the descending operation time T2 is set to be larger than the ascending operation time T3.

With the apparatus configured as described above, FIG.
The feeding position of the filler wire 2 is controlled by the procedure shown in FIG. That is, the voltage detection circuit 4 periodically detects the voltage between the filler wire 2 and the base material 3 (step S1), and the detected voltage is detected by the short circuit determination circuit 5.
Setting voltage 2.5V set by detection level setting device 6
(Step S2), when the detected voltage is 2.5V or less, it is determined that the short-circuited state, the rising command U is output, while the detected voltage is greater than 2.5V Is determined not to be in a short-circuited state, a down command D is output.

If it is not in the short circuit state, it is judged whether or not it is during the motor drive period according to the cycle T1 set by the motor drive cycle setter 8 (step S3), and if it is during the motor drive period, the descending operation is carried out. It is judged whether or not it is within the descending operation time T2 set by the time setting device 10 (step S4), and the motor drive circuit 7 is operated during the descending operation time T2.
The descending operation command is output to a (step S5), and the motor 7
The tip end position of the filler wire 2 is driven downward by
(Step S6). As a result, the tip of the filler wire 2 comes into contact with the molten pool (short-circuited state) from a state where the tip of the filler wire 2 is separated from the molten pool on the base material 3.

On the other hand, if it is in the short-circuit state, it is judged whether or not it is during the motor drive period according to the cycle T1 set by the motor drive cycle setter 8 (step S7). It is determined whether or not it is within the rising operation time T3 set by the rising operation time setter 12.
(Step S8), during the raising operation time T3, a raising operation command is output to the motor drive circuit 7a (step S9), and the tip end position of the filler wire 2 is driven to be raised by the motor 7 (step S10).

At this time, in this embodiment, the lowering operation time T
Since 2> the rising operation time T3 is set, the correction amount in the descending direction becomes larger than the correction amount in the ascending direction of the filler wire 2, and the insertion position of the filler wire 2 into the molten pool is set too downward. Welding can be performed in a state where the tip of the filler wire 2 is appropriately brought into contact with the molten pool, the occurrence of defects in the welded portion is reliably prevented, and the quality of the product is greatly improved.

Further, in this embodiment, the position correction amount of the filler wire 2 is defined by time by the descending operation time setting device 10 and the ascending operation time setting device 12, and each setting device 10,
By appropriately setting the set time by 12, the downward correction amount and the upward correction amount of the filler wire 2 can be freely adjusted.

[0017]

As described above in detail, according to the filler wire feeding position control method for non-consumable electrode type arc welding of the present invention, the periodic detection result of the voltage between the filler wire and the base material is obtained. When correcting and controlling the feed position of the filler wire based on this, set the filler wire insertion position too downward by setting the correction amount in the descending direction larger than the correction amount in the ascending direction of the filler wire. In other words, welding can be performed with the tip of the filler wire properly contacting the molten pool, defects can be prevented from occurring in the welded portion, and product quality is greatly improved.

[Brief description of drawings]

FIG. 1 is a flow chart for explaining a procedure of a filler wire feeding position control method for non-consumable electrode type arc welding as an embodiment of the present invention.

FIG. 2 is a block diagram showing the configuration of a non-consumable electrode type arc welding apparatus to which the present method is applied.

[Explanation of symbols]

 1 Electrode 2 Filler Wire 3 Base Material 4 Voltage Detection Circuit 5 Short Circuit Judgment Circuit 6 Detection Level Setting Device 7 Filler Wire Position Adjustment Motor 7a Motor Drive Circuit 8 Motor Drive Cycle Setting Device 9 Down Operation Command Circuit 10 Down Operation Time Setting Device 11 Up Movement command circuit 12 Rising movement time setting device

Claims (2)

[Claims] 1. In non-consumable electrode type arc welding in which the arc length is controlled by constant arc voltage control and the filler wire is fed to perform welding, the voltage between the filler wire and the base metal is periodically detected. Then, a filler wire feeding position control method for correcting and controlling the feeding position of the filler wire based on the detection result, wherein the correction amount of the feeding position of the filler wire is in the ascending direction of the filler wire. A filler wire feeding position control method for non-consumable electrode type arc welding, wherein a correction amount in the descending direction is set to be larger than a correction amount. 2. The filler wire feeding position control method for non-consumable electrode type arc welding according to claim 1, wherein the correction amount is defined by time.