KR101037894B1 - Torch triangle weaving method for welding on horizontal position - Google Patents

Abstract

The present invention is to provide a triangular weaving control method for preventing welding failure by the molten pool in the horizontal welding control of the hull shell plate, three points for triangular weaving of the welding surface of the upper member and the lower member. A first step of setting the weaving point of the; A second step of driving the welding device in a horizontal direction and welding the triangular weaving while sliding the welding torch to the three-weaving point set in the first step; Detecting a change amount of the welding torch output current for each weaving point; And a fourth step of controlling the weaving by varying the moving speed to the next point based on the change amount of the welding torch output current detected in the third step. The average output current between the points can be detected, the amount of change can be detected, and the change can be controlled to vary the speed of movement to the next weaving point by the amount of change.

Heat input, cross direction, welding, arc sensing, weaving, triangular weaving, molten pool

Description

 Torch triangle weaving method for welding on horizontal position}

In the present invention, in the horizontal welding control, the weaving method of the welding torch is controlled by the triangular weaving method, but the tilting or stacking amount of the melt pool is varied by varying the moving speed to the next weaving point based on the amount of current change at each weaving point. Corresponding to the triangular weaving control method for the high heat input lateral welding that can be welded control can be prevented correspondingly.

In general, the shipbuilding process is made by independently manufacturing hull blocks of various shapes and then combining the blocks with each other in a dock. 250 ~ 400 hull blocks are made to build one large ship, and there are about 200 welding cells (two vertical welds per cell) inside the hull block. Intersections should be welded.

An alternative application of welding equipment is vertical welding and welding of inclined portions in ship manufacturing processes. Welding is a basic structure of a welding device that welds two welding members (steel plate) to each other but the gap between the front bead and the welding member by melting the wire which becomes the welding material at the same time as the arc is generated from the welding part through the welding torch To form a back bead.

The above welding is a case of performing CO2 welding, but when the welding member (iron plate) is thick, the depth to be filled with molten metal is deepened, and thus the welder repeatedly performs several welding on the beads formed primarily. The way is to complete the welding.

However, repetitive welding by hand takes a long welding time, high defect incidence according to the degree of skill of the welder, and there is a limit to the phenomenon of flowing down beads and the use of high current by multi-pass welding.

In the case of the conventional vertical electrogas welding (EGW), as shown in (a) of FIG. 1A, the molten pool is almost accumulated, so that the welding quality is sensed even if the arc sensing method and the time point are sensed by a general method such as an average value or real time. In the case of horizontal electrogas welding (EGW), the arc length (torch height) is different for each weaving point because the molten pool is not only stacked inclined but also the stacking slope is not constant. When the arc sensing is performed by the vertical electro-gas welding method, the arc length varies greatly, which is very likely to cause welding defects such as fusion defects and undercuts.

In the conventional horizontal welding, the weaving method is controlled by a method of weaving two points. As described above, the melt pool is stacked by tilting, and the stacking angle and height are not constant. Due to this, the welding failure as shown in Figure 1b is generated.

The present invention is welded by the horizontal welding method by improving the conventional problems as described above, triangular weaving control method for the high heat input welding lateral welding to prevent welding interference by the molten pool by controlling the welding torch to triangular weaving It is to provide.

In addition, the present invention is to provide a triangular weaving control method for high heat input lateral welding to detect the change amount of the output current at each weaving point, and to independently control the arc length at each point based on each change amount of the current. will be.

The object of the present invention as such,

In the weaving control method for the hull shell welding,

Setting a three-weaving point for triangular weaving for the welded surfaces of the upper member and the lower member;

A second step of driving the welding device in a horizontal direction and welding the triangular weaving while sliding the welding torch to the three-weaving point set in the first step;

Detecting a change amount of the welding torch output current for each weaving point;

And a fourth step of controlling the weaving by varying the moving speed to the next point based on the amount of change in the welding torch output current detected in the third step.

In the third step, the amount of change in current for each of the three weaving points is the amount of change in output current for each point by comparing the output current of each point in the previous weaving cycle with the output current of each point in the current weaving cycle when weaving the three points. It is characterized by detecting.

In another method of the third step, the section average output current between each weaving point and the point is detected, the amount of change is detected by comparing the section average output current between the point and the point in the previous weaving cycle, and the section average is The movement speed to the next weaving point is varied by the output current change amount.

Alternatively, we detect the difference between the output current of any weaving point and the output current of the next weaving point, and weaving based on the output current difference when weaving moves from the any weaving point to the next weaving point in the next weaving cycle. It is characterized by varying the moving speed.

In addition, the present invention is characterized in that by setting a triangular weaving point to selectively control the V-shaped weaving and triangular weaving based on the amount of change in the output current of each weaving point.

In the present invention, in the horizontal welding control, the weaving method of the welding torch is controlled by a triangular weaving method, and the tilting and stacking of the molten pool is varied by varying the moving speed to the next weaving point based on the amount of current change at each weaving point. Welding control is possible in response to the change amount, thereby preventing the welding failure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of an automatic welding device for hull shell welding according to the present invention.

As shown therein,

A conveying rail 1 attached to the welding member by a plurality of magnet devices 2, a guide device 3 installed to travel on the conveying rail 1, and a Y provided in the guide device 3 Torch Y slide section 4 to slide in the direction, the torch Y slide section 4 is connected to the torch tilt section 5 for tilting the torch and the welding is connected to the torch tilt section 5 A control unit 6, an XZ slide unit 7 mounted on the welding control unit 6 to slide the torch in the XZ direction, a torch angle slide unit 8 connected to the XZ slide unit 7, And a welding torch 10 fixed to the torch clamp unit 9 and a torch clamp unit 9 connected to the torch angle slide unit 8.

The welding device configured as described above, the magnet device (2) on / off by attaching the welding device to the hull shell plate, and the guide device (3) is carried in the running direction by the rail (1) to perform automatic welding do.

The position, direction and angle of the torch can be positioned at the welding position through the Y slide section 4, the tilt section 5, the XZ slide section 7 and the torch angle slide section 8 to perform automatic welding. do.

The weaving control method according to the present invention, as shown in Figure 3, by performing the weaving control while welding the torch in the horizontal direction, provides a triangular weaving control method.

3 is a weaving control flow chart for the hull shell welding according to the present invention.

As shown therein,

A first step (S10) of setting three weaving points for triangular weaving on the welded surfaces of the upper member and the lower member;

A second step (S20) of driving the welding device in the horizontal direction and welding the triangular weaving while sliding the welding torch to three weaving points set in the first step;

A third step (S30) of detecting a change amount of the welding torch output current for each weaving point;

And a fourth step (S40) of controlling the weaving by varying the moving speed to the next point based on the amount of change in the welding torch output current detected in the third step (S30).

In addition, the present invention is characterized in that in the third step (S30) to detect the average output current between each weaving point and the point, the change amount is detected to vary the moving speed to the next weaving point by the change amount It is done.

4 is an explanatory diagram for explaining a triangular weaving control method according to the present invention.

The lower surface of the upper member 21 is formed as an inclined surface, the upper surface of the lower member 22 is formed as a horizontal surface, and performs the lateral welding of the welding device in a horizontal running. Conventionally, welding was performed by a two-point weaving method, but in the present invention, horizontal welding is processed by a triangular weaving method of moving three-weaving points (a, b, c). Here, the weaving points a, b, c is a weaving point that is moved by the triangular weaving control according to the present invention, a ', b' is a two-point weaving point of the conventional two-point weaving control method. That is, conventionally, the welding proceeds in the driving direction while weaving the welding torch to a weaving point of a'-b '. In this case, when the molten pool 23 flows down and accumulates, the slope or height is different, so that normal welding is difficult. There were many concerns about welding defects such as poor fusion, poor penetration, undercut, and underfill.

Accordingly, the present invention is controlled by the triangular weaving method is moved to the weaving point of the three points abc, by sensing the torch output current at each weaving point to adjust the moving speed between the weaving point to prevent welding failure by the fusion pool It is.

A first step S10 of setting three weaving points for triangular weaving on the welded surfaces of the upper member and the lower member is performed, and the user performs the test of the specimen for the three weaving points a, b, and c. It is input in advance from the control panel according to the thickness and groove angle, and the controller of the welding device is set as the weaving point of the torch.

Thereafter, the welding device is driven in the horizontal direction, and the second step (S20) of welding by triangular weaving is performed while sliding the welding torch to the three-weaving point set in the first step (S10).

Weaving points of three points by the welding process, the welding progress direction (View C) and the weaving point abc in the backward direction (View A) appears to be a straight line of different height, weaving is controlled by a triangle in the upper direction (View B) To make it happen.

When the welding proceeds in the triangular weaving method as described above, the stacking angle and amount of the melt pool 23 may be changed, and the distance between the torch and the melt pool at each weaving point may be changed, thereby changing the torch output current.

Therefore, a third step S30 of detecting a change amount of the welding torch output current for each weaving point is performed. It compares the welding torch output current at each point in the previous weaving cycle and the welding torch output current at each point in the current weaving cycle when weaving 3 points, and detects the change in output current for each point.

 Even if the current is set the same in the welding device, the output current changes when the height of the torch changes. That is, since the torch output current is changed by the interval between the torch and the melt pool, the present invention senses the change in the output current of the torch and performs triangular weaving control by automatically transferring the carriage in the welding direction.

As described above, the fourth step (S40) of controlling the weaving by measuring the amount of welding torch current at each weaving point and varying the moving speed to the next point based on the change amount of the welding torch output current.

In the method of varying the weaving point, the welding torch output current at each of the weaving points a, b, and c is detected as described above, and the feed speed of the welding torch is varied in proportion to the amount of change at each point. When the feed speed is variable, the welding progresses while the position of the weaving point is changed. By sensing the output current, if the amount of change in the output current is small, it moves at a relatively slow speed. If the amount of change is large, weaving control is performed to move at a relatively high speed.

For example, when the inclination of the melt pool 23 decreases and the output current change amount of the torch is generated, the feed speeds of the first and second axes of FIG. 3 are changed. That is, the weaving point B is changed to the position of B 'by increasing the backward moving speed of the first axis relative to the backward moving speed of the second axis. Here, axis 1 and axis 2 represent the direction of the vector conveyed by the weaving control of the welding torch as the axis. Since the scalar amount is fixed as an absolute value by the initial weaving point setting, the moving speed of each moving axis is varied and melted. Corresponding to the inclination and the amount of accumulation of the pool, welding failure is prevented.

On the other hand, the present invention, in the third step (S30) can detect the average output current between each weaving point and the point to detect the amount of change, based on the amount of change it is possible to variably control the moving speed between each point. . That is, the average output current of the welding torch is detected in each section between the weaving point and the point, and compared with the welding torch average output current in the section between the point and the point in the previous weaving cycle. The amount of change in the average output current is detected and the moving speed to the next weaving point is varied based on the amount of change in the section average output current.

Further, as another example of the present invention, the difference between the welding torch output current of any weaving point and the welding torch output current of the next weaving point is detected, and the output when weaving moves from the weaving point to the next weaving point in the next weaving cycle. It is also possible to vary the weaving movement speed based on the current difference.

In the second step, the V-shaped weaving or the triangular weaving may be selectively controlled based on the amount of change in the output current of each weaving point. It is possible to control the weaving in the form of a V-shape when triangular weaving alone is difficult to cope with the effective melt pool, and when the current variation is more than a certain threshold, the weaving control is performed. If it is within the triangular weaving method to control the melt flow irregularly or piled up to cope.

1A is an explanatory diagram of vertical welding and horizontal welding according to the prior art;

Figure 1b is an explanatory view of the weaving and normal welding and welding failure of the horizontal welding according to the prior art.

Figure 2 is a schematic view of the welding apparatus to which the present invention is applied.

Figure 3 is a flow chart showing a weaving control method according to the present invention.

4 is an explanatory diagram of a triangular weaving point according to the present invention;

5 is an explanatory diagram of the triangular weaving control according to the present invention;

<Description of the symbols for the main parts of the drawings>

1: rail 2: magnet device

3: guide device 4: torch Y slide part

5: torch tilt part 6: welding control part

7: Torch X-Z slide part 8: Torch angle slide part

9: torch clamp 10: torch

Claims (5)

In the weaving control method of high heat input lateral welding to move the welding device horizontally with respect to the welding surface and weld while weaving the welding torch, A first step of setting the weaving points of three points which are the moving points of the welding torch; A second step of controlling welding while controlling the weaving by moving the welding torch with respect to the weaving point set in the first step; Detecting a change amount of the output current of the welding torch together with the weaving control; And a fourth step of controlling the weaving by varying the speed of moving the welding torch to the next weaving point based on the change amount of the welding torch output current of the third step. Way. The method of claim 1, wherein the third step, When weaving three points, the welding torch output current at each point in the previous weaving cycle is compared with the welding torch output current at each point in the current weaving cycle. Triangular weaving control method for lateral welding. The method of claim 1, wherein the third step, Detects the average output current of the welding torch in each section between the weaving point and the point, and compares the average output current of the welding torch in the section between the point and the point in the previous weaving cycle. Triangular weaving control method for high heat input lateral welding, characterized in that for detecting the amount of change in the current. The method of claim 1, wherein the third step and the fourth step,  The difference between the welding torch output current of any weaving point and the welding torch output current of the next weaving point is detected, and the weaving movement speed is determined based on the output current difference when the weaving movement is performed from the any weaving point to the next weaving point in the next weaving cycle. Triangular weaving control method for high heat input lateral welding, characterized in that for varying. The method of claim 1, wherein the second step, Triangular weaving control method for high heat input lateral welding, characterized in that selectively controlling the V-shaped weaving or triangular weaving based on the output current change amount of each weaving point.

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