JPH067991B2 - Automatic welding equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to an automatic welding apparatus, and more specifically, it constantly secures a constant penetration shape and stress concentration regardless of changes in the groove state. The present invention relates to an automatic welding device having a new structure improved in order to obtain a surplus shape having a small amount of heat.

"Prior art" For example, LNG tank of LNG ship, railway bridge, etc.
For welded structures to which fatigue design is applied, the quality of the welded joint is improved and the reliability in strength is increased.Therefore, the reinforced shape of the welded joint should be strictly controlled to prevent stress concentration. Control is required.

Therefore, conventionally, in the welded structure to which the fatigue design is applied,
Since it meets the above requirements, it is shaped by mechanical processing (grinding, etc.) after welding, re-melting of the extra toe by TIG arc welding, and welding of small beads (called dressing bead method) Measures have been taken to smooth the shape.

However, such a measure is very poor in workability and is not a good idea.

On the other hand, recently, changes in groove state (cross-sectional area, root gap, etc.) for the purpose of obtaining a uniform back bead when butt welding plate and pipe materials from one side
Therefore, many proposals and researches have been made on an automatic welding device that detects the occurrence of welding and appropriately changes the welding conditions in response to the change in the groove state.

"Problems to be solved by the invention" However, in the conventional automatic welding device, a welding torch is mounted on the traveling carriage and the welding conditions such as the moving speed of the welding torch, the wire supply speed, and the current can be adjusted. However, the case where the fatigue design is applied was not taken into consideration, and the change in the groove state had to be grasped by the operator and the welding conditions had to be changed accordingly. In addition, taking this one step further, an automatic welding device that detects changes in the groove state using a groove sensor and automatically changes the welding conditions appropriately in response to changes in the groove state is also being researched. However, there have been various difficulties with the conventional techniques.

In addition, even with an automatic welding device that changes the welding conditions according to the change in the groove state as described above, it is not appropriate to partially avoid stress concentration when inspecting after the welding work. In some cases, the shape is too hard to say, so in order not to overlook this kind of inconvenience, it has been indispensable to inspect after welding work has been completed. Further improvement has been desired in terms of improvement of.

The present invention has been proposed in view of the above circumstances, and by more strictly controlling the welding conditions, it is possible to always ensure a constant melted shape regardless of the change in the groove state, and to prevent stress concentration from occurring. It is possible to obtain the shape, and therefore the reliability of the quality and strength of the welded joint can be further improved, and there is no need to perform a special inspection of the welded state after the welding work is completed, and workability is improved. It is an object of the present invention to provide an excellent automatic welding device even in improving the welding cost.

"Means for Solving Problems" The automatic welding apparatus of the present invention has several theories determined by performing multiple regression analysis on bead shape parameters and welding condition parameters of welding joints, that is, the stress concentration factor is the largest. The toe radius of the affected weld has a strong correlation with the flank angle, and this flank angle also has a strong correlation with the bead height, and as a result, the toe radius becomes a bead height that can be controlled as a welding parameter. The bead height is not a single parameter but has a strong correlation with the bead width, and the bead height and bead shape parameters for keeping the stress concentration factor within the specified value are the bead height and the bead width. It suffices to control the excess welding cross-section area, which is the product of the bead width, and the amount of welding per unit time is determined by the welding current.
On the other hand, the welding cross-sectional area is obtained as the sum of the groove cross-sectional area and the excess cross-sectional area, and the welding speed is obtained as a function of the welding cross-sectional area and the welding amount. A welding torch is mounted on a trolley, an automatic welding machine capable of adjusting welding conditions such as a moving speed of the welding torch, a wire supply speed to the welding torch, and a current value applied to the wire, and a portion to be welded. The welding state is detected by the groove detection device that detects the groove state and outputs a signal according to the detection result, and the excess state detection sensor that is arranged immediately after the moving direction of the welding torch, and analyzes this detection result.・ A welding state detection device that evaluates and outputs a predetermined signal, and sets welding conditions such as the torch movement speed of the automatic welding machine and the current value applied to the wire by the output signal of the groove detection device. At the same time, it is essential to include a main controller that corrects the welding conditions according to the signal from the welding state detection device.

[Operation] With such a configuration, the welding conditions set by the groove state are further corrected according to the welding state immediately after welding. In comparison, it is possible to control welding conditions more strictly, it is possible to always maintain a constant penetration shape regardless of changes in the groove state, and to obtain a surplus shape with less stress concentration. Therefore, the reliability of the quality and strength of the welded joint can be further enhanced.

Further, since the welding state is sequentially inspected during the welding work by the welding state detection device, the welding state inspection work is finished almost at the same time as the welding work is finished, and the work time is shortened and the workability is improved. You can also

"Embodiment" Hereinafter, one embodiment of an automatic welding apparatus according to the present invention will be described with reference to the drawings.

FIG. 1 shows a perspective view of an automatic welding apparatus 1 of one embodiment.

The automatic welding device 1 is composed of an automatic welding machine 2, a groove detection device 3, a welding state detection device 4, a main control device 5, and the like.

The automatic welding machine 2 has a traveling carriage 7 guided by a rail 6 and capable of adjusting traveling speed, and equipped with a welding torch 8 and a wire feeder 10 for automatically supplying a welding wire 9 to the welding torch 8. The traveling speed of the traveling carriage 7 is adjusted to set the moving speed of the welding torch 8. The welding torch 8 is attached so that its position can be adjusted, and is arranged separately from the traveling carriage 7. The power supply 11 supplies voltage and current.

The groove detection device 3 detects the groove state of the welded portion,
A signal according to the detection result is output, and as shown in FIG. 2, a groove detection sensor 3a located immediately before the moving direction of the welding torch 8 for detecting the groove state, and the groove detection. It is provided with an output section 3b which receives a signal from the sensor 3a to read the groove state, analyzes the read data, and outputs a command value according to the analysis result as information, and FIG. As shown in, groove detection sensor 3a
Is attached to the traveling carriage 7 so that its position can be adjusted by the position adjusting mechanism 3c. The groove detecting sensor 3a includes a laser diode and a one-dimensional semiconductor position detecting element (PS
D) is a non-contact type sensor, and, for example, when the welded portion is a butt weld that takes a groove between the plate materials 12 and 12 as shown in FIG. 3, the groove detection sensor is used. When the detection data of 3a is sent to the output unit 3b,
Immediately, the position of the root gap G at the groove center C, the groove angle α, etc. are analyzed.

The welding state detection device 4 immediately detects the welding state of the portion where welding is completed by the welding torch 8 and outputs a signal according to the detection result. As shown in FIG.
Excessive scale detection sensor 4a located immediately after the moving direction of the welding torch 8 to detect the welding state, and the extra scale detection sensor
The welding state is read in response to a signal from 4a, the read data is analyzed and evaluated, and an evaluation output section 4b that outputs a command value corresponding to this evaluation as information is provided, and FIG. As shown in,
The position 4a is attached to the traveling carriage 7 so that the position of the position adjusting mechanism 4c can be adjusted. The excess detection sensor 4a,
The welding shape is measured by a light wave cutting method using a non-contact type sensor that is a combination of a laser diode and a CCD camera. For example, as shown in FIG. When the data measured by the extra-height detection sensor 4a is sent to the evaluation output unit 4b when the butt welding is performed in advance, the bead width W, the bead height h, W / h, etc. are immediately analyzed. It is like this.

In addition, the measurement by the excess detection sensor 4a is shown in FIG.
As shown in (A), the specified pitch P along the weld 13
It is done every time.

Information measured by the excess detection sensor 4a, that is,
As shown in FIG. 5 (B), the information obtained by irradiating the laser from the laser diode to the welded portion (the image as shown in FIG. 5 (D) by the light section image) is immediately shown in FIG. (E) is converted into shape data, and the bead width W, bead height and W / h drop are analyzed from this shape data, and this shape data is recorded in the bubble memory.

After the welding is completed, the bubble memory is applied to an analyzer (bubble reader), and the shape data (the bead width W, the bead height h, the flank angle θ, the toe radius ρ) and the stress concentration coefficient Kt are output, and the pass / fail is determined. .

The main control device 5 receives information from the above-mentioned detection devices 3 and 4, and based on these information, the automatic welding machine 2
Of the welding torch 8, in addition to controlling operations such as automatic copying of the welding torch 8 and starting and stopping of the welding operation, specifically, the moving speed of the welding torch 8 (that is, the traveling carriage 7). Welding speed) and the current value applied to the wire 9 are set, and the set welding conditions and the measurement results of the detection devices 3 and 4 are displayed by an appropriate means.

The function of the main controller 5 will be described in detail with reference to FIG. 2. The main controller 5 includes welding condition data such as a groove state, welding current, welding speed (moving speed of the torch), and the like. The storage circuit 5a storing the program and the information from the detection device 3 are arithmetically processed in accordance with the data and the program stored in the storage circuit 5a to calculate the welding condition that optimizes the welding state. Further, a central processing circuit 5b for correcting the information based on the information of the detection device 4, measurement data of each detection device 3 and 4 and a central processing device
An interface 5c for displaying the welding conditions calculated by 5b and a position control input for aligning the welding torch 8 with the groove center C of the welded portion based on the information of the groove detection device 3. An output circuit 5d, a welding condition input / output circuit 5e for operating each part of the automatic welding machine 2 under the welding conditions calculated by the central processing circuit 5b, a plate thickness or a groove shape of a welded part, or double-sided welding. It is equipped with an input section 5f (see Fig. 1) for manually inputting the initial conditions of welding, such as single-sided welding or the like, and outputs commands to equipment, speed commands, current commands, voltage commands, etc. Is detected and an abnormality command is input, the operation is stopped.

The welding condition file to the memory circuit 5a is a proper welding condition when the root gap G is zero (welding condition capable of suppressing the stress concentration coefficient Kt of the joint portion to a set value or less).
May be input as a function of the plate thickness of the welded portion, and each time the plate thickness changes by 1 mm, the corresponding appropriate welding condition may be input in a matrix formula.

The operation, sequence, etc. when welding is performed using the automatic welding device 1 will be described below with reference to FIG.

First, when starting the work, a welding preparation work is performed. This preparatory work includes alignment of the traveling carriage 7 and inspection of each part of the welding machine 2.

Next, the welding conditions are set. The welding condition setting in this case is performed by operating the key on the operation panel of the main controller 5 and manually inputting the predetermined input data S1. The input data S1 is the plate thickness, groove shape, double-sided welding or single-sided welding of the welded part. When these data are input, the data stored in the memory circuit 5a of the main controller 5 is appropriate. Welding conditions are selected and set.

After confirming that the welding conditions have been set, pressing the welding start button of the main controller 5 starts welding. At this welding start step (indicated by S2), the groove detection device 3 is started, and the position of the groove center C and the root gap G are detected by the measurement data of the groove detection sensor 3a.
The information is sent to main controller 5. When the position of the groove center C and the root gap G are detected, the groove detection sensor 3a stops moving. On the other hand, the main controller 5 uses the information sent from the groove detector 3 to weld the torch 8
When a predetermined signal is sent to the welding machine 2 so that is positioned at the groove center C, welding conditions corresponding to the information are set, and the welding conditions match the welding conditions set by the input data S1. The welding machine 2 as shown in S3.
A start signal is sent to each of the parts, and when the welding conditions do not match the set welding conditions, the welding conditions are reset based on the information and the start signal is sent to each part.

Then, a few seconds after the start signal is sent from the main control device 5 to each part, the pre-flow of the shield gas and the feeding of the wire are started, the arc starts to be generated, and a few seconds after the arc is generated, the traveling carriage 7 starts to travel. , Welding is carried out.

During welding, the groove detector 3 measures the groove state of the welded portion and sends the information to the main controller 5,
The main controller 5 performs a predetermined calculation based on the information, and as shown in S4, if there is a change in the groove state, resets the welding conditions accordingly, and the welding torch 8 is set to the groove center C. The command signal is output to each part of the welding machine 2 so that the welding position is maintained and the penetration depth D is kept constant and a surplus shape with less stress concentration is obtained. The welding conditions reset in this case are welding current and welding speed (travel speed of the traveling carriage), for example, the route gap G.
Is higher than the standard, reduce the welding current and welding speed. By controlling the welding current and the welding speed in this way, the penetration depth D can be made constant, and the bead height h, the flank angle θ, the toe radius ρ, etc. can be kept constant.

On the other hand, the welding state detection device 4 is started at approximately the same time as the welding is performed or at a slight delay. The welding state detection device 4 analyzes the data measured by the extra-height detection sensor 4a to obtain the bead width W, the bead height h, the flank angle θ, the toe radius ρ, and the like, as described above. It is evaluated whether the surplus shape satisfies the set stress concentration coefficient Kt. On the other hand, the measured data is stored in the bubble memory and the information is sent to the main controller 5. If the stress concentration coefficient Kt does not satisfy the set value, based on these pieces of information, the main controller 5 executes S5.
A change signal is issued as shown in S6, and secondary welding conditions such as increasing or decreasing the welding speed are corrected so that Kt approaches the set value.

The above-mentioned evaluation of the welding condition can be performed in synchronization with the welding speed, and the specified distance (for example, 10mm, 50mm, 100mm, etc.)
Is done in units.

During welding, truck overload, arc break,
When an abnormality such as falling out occurs and an abnormality command is input to the main control device 5, the welding machine 2 is stopped by the abnormality signal as shown in S7. If there is no abnormal command,
When the welding operation is continued as it is and it is detected that the series of welding operations are completed by the limit switch arranged at the end of the welding line, as shown in S8 and S9, the main controller 5 sends a stop signal to the welding machine 2. Is issued and the welding operation is stopped.

As described above, in the automatic welding apparatus 1, since the welding condition set by the groove state is further corrected according to the welding state immediately after welding, the conventional welding condition is set only by the groove state. Welding conditions can be controlled more rigorously compared with the ones, and it is possible to always obtain a constant penetration shape regardless of changes in the groove state and to obtain a surplus shape with less stress concentration. Therefore, the reliability of the quality and strength of the welded joint can be further improved.

Further, since the welding state is sequentially inspected by the welding state detection device 4 during the welding work, the welding state inspection work is finished almost at the same time as the welding work is finished, and the work time is shortened and the workability is improved. To do.

"Effects of the invention" As is clear from the above description, in the automatic welding apparatus of the present invention, the welding condition set by the groove state is further corrected according to the welding state immediately after welding, Welding conditions can be controlled more strictly compared to the conventional one in which welding conditions are set only in the groove state, and regardless of changes in the groove state, a constant penetration shape is always secured, and It is possible to obtain a surplus shape with less stress concentration, and therefore, the quality and strength reliability of the welded joint can be further enhanced.

Further, since the welding state is sequentially inspected during the welding work by the welding state detection device, the welding state inspection work is finished almost at the same time as the welding work is finished, and the work time is shortened and the workability is improved. You can also

[Brief description of drawings]

FIG. 1 is a perspective view of an automatic welding apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram thereof, FIG. 3 is an explanatory view of a welded portion, and FIG.
The figure is an illustration of the extra-height shape, and Fig. 5 (A) (B) (C) (D)
(E) is an explanatory view of the measurement by the excess detection device,
Of these, FIG. 5 (C) is a view taken along the line CC of FIG. 5 (B), and FIG. 6 is a flow chart for explaining the work procedure of the one embodiment. 1 ... Automatic welding device, 2 ... Automatic welding machine, 3 ... Groove detection device, 3a ... Groove detection sensor, 3b ... Output part, 4 ...
… Welding condition detection device, 4a …… Extra scale detection sensor, 4b ……
Evaluation output unit, 5 ... Main controller, 5a ... Memory circuit, 5b ...
... Central processing circuit, 5c ... Interface, 5d ... Position control input / output circuit, 5e ... Welding condition input / output circuit, 5f ...
… Input section, 7 …… Truck, 8 …… Welding torch, 9 ……
Welding wire, 10 …… Wire feeder, 11 …… Power supply, 12…
… Plate material, 13… Welded part,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Irisawa 1 Shinshinakahara-cho, Isogo-ku, Yokohama, Kanagawa Ishi Kawashima Harima Heavy Industries Co., Ltd. Technical Research Institute

Claims (1)

[Claims] 1. An automatic welding machine in which a welding torch is mounted on a traveling carriage, and welding conditions such as a moving speed of the welding torch, a wire feeding speed to the welding torch, and a current value applied to the wire can be adjusted. And a groove detection device that detects the groove state of the welded part and outputs a signal according to the detection result,
A welding state detection device that detects the welding state by a surplus detection sensor arranged immediately after the welding torch moving direction and outputs a predetermined signal by analyzing and evaluating the detection result, and the groove detection device. Automatic welding with a main controller that sets welding conditions such as a torch moving speed of the automatic welding machine and a current value applied to a wire by an output signal, and corrects the welding conditions by a signal of the welding state detection device apparatus.