JPH07185809A - Automatic control device in submerged arc welding - Google Patents

Abstract

PURPOSE:To automate and speedup submerged welding by automatically changing/controlling the welding condition so as to obtain a welding leg length corresponding to a base metal to be welded when continuous welding of linear/ curved welding place is executed in a base metal to be welded. CONSTITUTION:The device is provided with a setting value inputting means 21 to input the discrete setting value for a base metal 1 to be welded, the setting value inputted in the setting value inputting means and welding actual value are compared, by this comparing signal, for the base metal to be welded in which a plate thickness (t) of a base metal to be welded along the welding running direction is irregularly changing from t1 to t2, in order to obtains a welding leg length s1-s2 corresponding to a plate thickness at welding place, a relative running speed between a welding bar 7 and base metal 1 to be welded, welding bar feed speed, arc voltage and arc current are automatically controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for automatically controlling welding conditions in metal welding, particularly in submerged arc welding, and particularly in long continuous welding, welding suitable for the plate thickness of a base metal to be welded. In order to obtain the leg length, the welding conditions, such as the relative traveling speed of the base metal to be welded and the electrode of the welding rod, the feed speed of the welding rod, the welding voltage and the welding current are automatically changed and controlled, and the plate thickness of the base metal to be welded is controlled. The present invention relates to an automatic control device in submerged arc welding for welding to a welding leg length corresponding to the above.

[0002]

2. Description of the Related Art As is well known, in metal welding, submerged arc welding supplies granular flux from a flux hopper to a welding site on a base metal to be welded, and reels are fed into the granular flux. The tip of the coiled welding rod that is sent out from is thrust and continuously guided, the welding rod is used as one electrode, and the base metal to be welded is used as the other electrode, and the power source is connected to the welding power source. And a base metal to be welded to generate an arc in a latent arc state to perform metal welding.

In this submerged arc welding, a large current can be passed because the current is applied at a position immediately before the arc is generated.
Since the arc atmosphere is shielded by the molten slag film inside the accumulated granular flux, the heat concentration is good, the melting speed of the welding rod is high, the penetration of the base metal to be welded is large, and high-speed welding is possible. Possible, building,
It is widely used in the field of metal welding processing in factory production lines for steel materials for civil engineering such as bridges.

In the welding apparatus for the submerged arc welding, any of a DC power source, an AC power source, and an AC / DC power source has been put into practical use as a welding power source. Further, an apparatus equipped with an automatic control mechanism for keeping the arc voltage constant by adjusting the feeding speed of the welding rod has been developed and provided.

In the conventional submerged arc welding apparatus, a welding head, a welding rod feeding mechanism, an automatic control mechanism and the like are placed on a trolley, which is automatically moved along a linear welding site of a base metal to be welded on a rail. We are doing welding. When the welded portion of the base material to be welded is curved, for example, automatic control welding can be performed by rotating the side of the base material to be welded.

In the submerged arc welding device, the electrode on the side of the base material to be welded is usually composed of one welding rod on the electrode on the side of the welding rod, but the welding efficiency is improved. , For the purpose of limiting the penetration in the case of overlaying, a pair of welding rod electrodes (a leading electrode arranged first along the welding traveling direction and a trailing electrode arranged later along the welding traveling direction) is provided, whereby There is also one configured to perform efficient multi-electrode welding.

[0007]

In the above-described submerged arc welding, in continuous welding of a long base metal to be welded, for example, the plate thickness of the base metal to be welded changes along the welding traveling direction. In this case, naturally, the welding leg length at the welding site must be changed according to the plate thickness of the base material to be welded so as to match the plate thickness of the base material to be welded. Factors that change the welding leg length described above include welding conditions, for example, changes in the relative welding running speed between the welding rod and the base metal, the welding rod feeding speed, the arc voltage, and the arc current. Conventionally, when performing submerged arc welding on a base metal having the above-mentioned properties, a preset method by a welding operator is merely used for changing and setting welding conditions, and a complicated work is forced, and a submerged arc is required. It was not possible to comply with high-speed automation in welding.

Therefore, the present invention is intended to solve the above-mentioned drawbacks and problems found in the conventional submerged arc welding, and an automatic control device for welding conditions, that is, welding, which has a novel structure therefor, that is, welding. The plate thickness t of the base material to be welded is the plate thickness t along the welding traveling direction.
₁ when ~t _n and irregularly changing as, to obtain a weld leg length s ₁ ~s _n corresponding to the thickness t ₁ ~t _n of the welding base material in each weld site, automated welding conditions An object of the present invention is to provide an automatic control device in submerged arc welding which can be controlled in a controlled manner.

[0009]

To achieve the above object, the present invention specifically provides a granular flux to a welding site on a base metal to be welded, and a welding rod material in the granular flux. Of the welding rod as one electrode, the base material to be welded as the other electrode of the welding power source is connected to the welding power source, between the tip of the welding rod and the base material to be welded. In submerged arc welding in which an arc in a latent arc state is generated to perform welding, an automatic control system for automatically controlling welding conditions to obtain a welding leg length s corresponding to the plate thickness t of the base material to be welded And
The welding rod means for guiding the tip of the welding rod along the welding site in the base metal to relatively move and move the welding rod and the base metal, and the welding rod Welding rod feed-out means for continuously feeding out to the welding site in the base metal to be welded, arc voltage adjusting means for adjusting the arc voltage applied between the welding rod and the base metal to be welded An arc current adjusting means for adjusting an arc current applied between the welding rod and the base metal to be welded, and a set value for inputting a specific set value for the base metal to be welded. An input means, and compares the set value input to the set value input means with the actual welding value, and the welding traveling means, the welding rod feeding means, the arc voltage adjusting means, and the above-mentioned by the comparison signal. Arc current adjusting hand Controls, thickness t of the welding base material to be welded, along a weld running direction, the thickness t ₁ ~t
_{For the} base metal to be welded that changes irregularly with _n , the weld leg length s ₁ ~ depending on the plate thickness of the base metal to be welded at each welding site
Automatic control device in submerged arc welding for automatically adjusting and controlling the relative traveling speed of the welding rod and the base metal, the feeding speed of the welding rod, the arc voltage and the arc current so as to obtain s _n It is what constitutes.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An automatic control device for submerged arc welding according to the present invention will be described in detail below with reference to specific embodiments shown in the drawings. FIG. 1 is for explaining the basic principle of an automatic control device in submerged arc welding according to the present invention, and FIG.
It is a schematic explanatory drawing which shows the basic composition of the submerged arc welding apparatus which concerns on application of this invention, and FIG. 1B is a schematic perspective view of one concrete form of the to-be-welded base material to be welded in this invention. It is shown in the figure.

The present invention relates to a submerged arc welding apparatus, and more particularly, to automatically set and control welding conditions thereof, and in particular, to fillet welding of a base metal 1 to be welded having a structure as shown in FIG. 1B. Applied very effectively to. That is, the base material 1 to be welded having the structure shown in FIG. 1B.
Applies one plate 1A to the surface of another plate 1B on both side edges at a certain angle (angle of 90 ° in the example shown in the figure), and applies it to the corners (welding sites) of both plates. , Molten metal is poured, and a fillet is formed to be welded.
In addition, in the present invention, the target base metal to be welded is not limited to the structure shown in FIG. 1B, and is also applied to the base metal to be welded having a curved welded portion. Is possible.

The automatic control apparatus for submerged arc welding according to the present invention is the same as in the above-mentioned fillet welding, in which side plates 1B and 1B having different structures are simultaneously formed on both side edges of one plate 1A. FIG. 1B includes a specific example in which continuous continuous welding is possible.
As shown in FIG. 3, during the welding process of the base metal to be welded such that the plate thicknesses of the side plates 1B and 1B vary irregularly with the plate thicknesses t _{1 to} t _n along the welding traveling direction, the welding at each welding site This is very effectively applied when automatically changing the welding leg lengths s _{1 to} s _n according to the plate thickness of the welding base material.

In the base metal 1 to be welded shown in FIG. 1B, the side plate 1B has a plate thickness t ₁ at a distance L ₁ between a position P ₀ and a position P _{1 in the} welding traveling direction, and a position P ₁ to a position P _1. in the distance L ₂ between the _two, a plate thickness t _2, the distance L ₃ between the position P ₃ from the position P _2, a plate thickness t _3, along a weld running direction, the plate thickness irregularity It consists of things that change to. In the present invention, the pair of side plates 1B, 1B may have different structures. That is, the position P and the distance L at which the plate thickness changes may be different from each other.

Next, the basic structure of the submerged arc welding apparatus will be described with reference to FIG. 1A. The submerged arc welding apparatus SA includes a granular flux supply mechanism 2, a welding rod feeding mechanism 3, a welding power source 4, and a voltage controller 5. The granular flux supply mechanism 2 includes a flux hopper 6 and continuously supplies the granular flux F from the flux hopper 6 to a welding site on the base material 1 to be welded. On the other hand, the welding rod feeding mechanism 3 feeds the welding rod 7 wound on a reel so that the welding rod 7 may be positioned at the welding site during the welding period with its tip continuously thrust into the granular flux. It includes a welding rod feeding motor 8 connected to the welding power source 4 via a voltage controller 5 and an unwinding roller 9 mechanically connected to the motor 8. The welding rod 7 is composed of the welding cable 10 and the energizing contact 11.
It is electrically connected to the welding power source 4 to form one electrode. On the other hand, the base material 1 to be welded is electrically connected to the welding power source 4 by the ground cable 12 and forms the other electrode.

In the present invention, the submerged arc welding apparatus SA is intended to simultaneously and continuously perform two welding portions extending parallel to the welding traveling direction on the base material 1 to be welded as shown in FIG. 1B. Reference side welding mechanism BM
And the subordinate side welding mechanism FM are configured in a double structure. The reference-side welding mechanism BM and the subordinate-side welding mechanism FM are respectively arranged in advance in the welding traveling direction.
In addition, the rear electrode E2 is provided with a pair of electrodes which are disposed later along the welding traveling direction.

Next, the automatic control device for submerged arc welding according to the present invention will be described in detail with reference to FIGS. 2 is a schematic block diagram of the automatic control system, FIG. 3 is a schematic block diagram showing an operation mode of a sequencer based on touch panel operation in the system, and FIG. 4 is a schematic diagram of the touch panel. 4A shows a layout example in the welding condition setting mode, FIG. 4B shows a layout example in the automatic operation input mode, and FIG. 4C shows a layout example in the automatic operation display mode.

According to FIG. 2, the automatic control apparatus for submerged arc welding according to the present invention is provided with a touch panel 21 capable of data input operation and data display in a ten-key and tea-teng mode. The touch panel 21 includes work position data, work model setting,
Set operation command, welding speed data, welding current data, welding voltage data, and display welding traveling position data, welding speed data, welding current data, welding voltage data, operation display data, error display, etc. The sequencer 22 is for sequentially advancing each step of control according to a predetermined order, and the touch panel 21
The touch panel 2 outputs various command signals and inputs answer signals based on the data input by the touch panel 2
Communicate information to 1. A voltage / ammeter indicating operation panel 23 is connected to the sequencer 22. On the other hand, the voltage adjusting device 24 is a combination of a servo motor 25 and a potentiometer 26, and drives the servo motor 25 based on a signal from the sequencer 22 to displace the potentiometer 26 and output an adjusted voltage signal.

The adjusted voltage signal from the voltage adjusting device 24 is input to the welding machine controller 27 to operate the welding machine controller 27. One pole 28 of the welding power source in the welder controller 27 is connected to the base material side to be welded, and the other pole 29 is connected to the welding rod side. The current increase / decrease signal from the sequencer 22 is the welding machine control device 2.
7, the sequencer 22 and the welding machine control device 27 are connected to each other. The welder controller 27 is configured to feed back the actual welding voltage 30 and the actual welding voltage 31 during welding to the sequencer 22.

Next, an operation procedure of the automatic control device in the submerged arc welding according to the present invention will be described. First, as shown in FIG. 4A, the touch panel 21
Is set in the welding condition setting mode and the welding leg length s is set. When setting the welding leg length, press part (2) to set the reference side, and press part (3) to set the subordinate side, and enter numerical values using the numeric keypad. This welding leg length s is usually a lower limit value of 6 mm to an upper limit value of 9 mm. When setting the welding current and welding voltage, refer to (4) separately for the leading and trailing sides of the reference side and the leading and trailing sides of the subordinate side.
Part to (11), and input numerical values using the numeric keypad. Normally, the welding current is lower limit value 400A
-Upper limit value is 1500A and welding voltage is lower limit value 20V
-Upper limit value is 60V. On the other hand, when setting the welding speed, press section (12) and enter a numerical value using the numeric keypad. Usually, the welding speed is a lower limit value of 60 cm / min to an upper limit value of 160 cm / min.

After the welding conditions are set on the touch panel 21, the display modes are switched by operating the parts (16) to (20). FIG. 4B illustrates an automatic operation input mode by operating the part (16), and FIG. 4C illustrates an automatic operation display mode by operating the part (17). Weld length L in automatic operation input mode
If INC is set by INC, operate part (3) to move the distance L from the welding start position P ₀ to the first leg length change position P ₁
Enter ₁ as the numerical value. Similarly, the distance L ₂ from the _first leg length change position P ₁ to the second leg length change position P _{2 is shown in the} part (4), and the second leg length change position P ₂ is shown in the part (5).
From, the distance L ₃ to the leg length change position P ₃ of the third time,
In section (6), the distance L ₄ from the _third leg length change position P ₃ to the fourth leg length change position P _{4 is} numerically set and input. Further, in the device of the present invention, the data can be set by stopping at an appropriate changing position during driving and driving and operating the teaching writing button.

In the automatic operation input mode, the welding leg length s
To set the reference side and the conforming side respectively, operate parts (8) to (17) to start welding from the welding start position P ₀ .
Welding leg s ₁ to leg changed position P ₁ of the first time, the leg length change position P ₁ of the first time, a welding leg length s ₂ until leg change position P ₂ a second time, from the leg length change position P ₂ a second time ,
Welding leg s ₃ to the third-time leg change position P _3, the leg length change position P ₃ of the third time, fourth-time leg change position P ₄
Enter the welding leg lengths s _{4 up} to and including the numerical values.

On the other hand, in the automatic operation input mode, (29)
When the section is operated, the screen is switched to the automatic operation display mode as shown in FIG. 4C. In the automatic operation display mode, the reference side welding leg length during automatic operation is displayed in (1), the secondary welding leg length in automatic operation is displayed in (2), and the welding side length during welding is displayed in (3). The reference side leading current is in part (4), the reference side trailing current in welding is in part (5), the subordinate side leading current in welding is in part (6), the subordinate side in welding. The trailing current is displayed.The reference side preceding voltage during welding is displayed in (7), the reference side trailing voltage during welding is displayed in (8), and the subordinate side during welding is displayed in (9). Leading voltage is (10)
The trailing voltage on the subordinate side during welding is displayed on the
The welding traveling speed during automatic operation is displayed in the section. Furthermore, in the automatic operation display mode, the current position during automatic operation is displayed in (13), the distance to the next welding leg length change position during automatic operation is displayed in (14), and (15). In the section, the next welding leg length change position during automatic operation is displayed, in the (16) section, the next reference side welding leg length during automatic operation is displayed, in the (17) section,
The next welding leg length on the subordinate side during automatic operation is displayed.

[0023]

According to the automatic control apparatus for submerged arc welding of the present invention having the above-described structure, in continuous welding of a long length, the plate thickness t of the base metal to be welded is When the plate thickness t _{1 to} t _n varies irregularly, the plate thickness t of the base metal to be welded at each welding site
So as to obtain a weld leg length s ₁ ~s _n corresponding to ₁ ~t _n, welding conditions, for example, the relative travel speed of the welding rod electrodes and the welding base material, feeding rate of the welding rod, welding voltage and welding current Is automatically controlled and welded to a welding leg length according to the plate thickness of the base metal to be welded, which greatly contributes to the automation and speedup of submerged arc welding and to the improvement of productivity. Therefore, it can be said that it works extremely effectively in these respects.

[Brief description of drawings]

FIG. 1 is a view for explaining a basic principle of an automatic control device in submerged arc welding according to the present invention, and FIG. 1A is a basic configuration of a submerged arc welding device according to an application of the present invention. FIG. 1B is a schematic perspective view showing one specific form of the base material to be welded to be welded in the present invention.

FIG. 2 is a schematic block diagram of an automatic control system in an automatic control device in submerged arc welding according to the present invention.

FIG. 3 is a schematic block diagram showing an operation mode of a sequencer based on a touch panel operation in the system.

FIG. 4 is a layout example of a touch panel, FIG. 4A is a layout example in a welding condition setting mode, FIG. 4B is a layout example in an automatic operation input mode, and FIG.
FIG. 4 is a schematic front view showing a layout example of a display mode during automatic driving.

[Explanation of symbols]

 1 Base material to be welded SA submerged arc welding device 2 Granular flux supply mechanism 3 Welding rod feeding mechanism 4 Welding power source 5 Voltage controller 6 Flux hopper F Flux 7 Welding rod 8 Welding rod feeding motor 9 Unwinding roller 10 Welding cable 11 energizing contact 12 ground cable BM reference side welding mechanism FM subordinate side welding mechanism E1 leading electrode E2 trailing electrode 21 touch panel 22 sequencer 23 voltage / ammeter indicating operation panel 24 voltage regulator 25 servo motor 26 potentiometer 27 welding machine control apparatus

Claims (2)

[Claims] 1. A granular flux is supplied to a welding site on a base material to be welded, the tip of the welding rod is continuously guided into the granular flux, and the welding rod is used as one electrode, In the submerged arc welding, the power source is connected to the welding power source as the other electrode of the welding base metal, and an arc in a latent arc state is generated between the tip of the welding rod and the base metal to perform welding. An automatic control system for automatically controlling welding conditions so as to obtain a welding leg length s corresponding to a plate thickness t of the base material to be welded, the tip of the welding rod being along a welding site in the base material to be welded. And a welding running means for relatively moving the welding rod and the base material to be welded relative to each other, and a welding rod for continuously sending the welding rod toward a welding site in the base material to be welded. Sending means, the welding rod And an arc voltage adjusting means for adjusting an arc voltage applied between the base metal to be welded, an arc current applied between the welding rod and the base metal to be welded. Arc current adjusting means and a set value input means for inputting a set value specific to the base metal to be welded, and compares the set value input to the set value input means with the actual welding value. Then, the welding traveling means, the welding rod feeding means, the arc voltage adjusting means and the arc current adjusting means are controlled by the comparison signal so that the plate thickness t of the base metal to be welded is the welding traveling direction. Along the plate thickness t ₁ ~
For the base metal to be welded that changes irregularly with t _n , the weld leg length s ₁ according to the plate thickness of the base metal to be welded at each welding site
So as to obtain a ~s _n, characterized in that the said relative travel speed of the welding rod and the base material, so as to automatically adjust control speed feeding welding rod, arc voltage and arc current submerged Automatic control device for arc welding. 2. The submerged arc welding according to claim 1, wherein the welding rod material comprises a first welding rod material forming a leading electrode and a second welding rod material forming a trailing electrode. Automatic control device.