JPS6195778A - Automatic welding device - Google Patents

Abstract

PURPOSE:To provide the automatic welding device enabling to control automatically the arc length and posit of the welding torch on a travelling truck via D/A and A/D convertors respectively from the input data into a memorizer of all the welding parameter according to welding conditions operated by a central processing unit. CONSTITUTION:A welding power source 4 and control device 5 are provided on the welding truck 2 equipping the welding torch 3 moving with swivelling around the welding part of the tubular body W to be welded and a filler metal feeding device 4. And a welding parameter setting device 7, memorizer 8, central processing unit 9, each D/A convertor 10, 12 and A/D convertor 13 are respectively connected and provided on the device 5. Due to a proper arc length being obtainable always by said constitution therefore the proper conditions selecting work is made easy, also the errors due to an individual difference and misoperations are eliminated are eliminated and the efficiency in welding work can be elevated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an automatic welding device for joining and welding pipe bodies (workpieces) to be welded that are left horizontally, for example.

[Technical background of the invention and its problems]

In general, automatic welding means for welding tubes to be welded is configured to weld a welding torch provided on a welding truck while rotating around a joint portion of the tube to be welded (workpiece).

In particular, automatic three-joint means for fixed pipe bodies to be welded is performed by all-position welding, and the ura wave beat of urana welding in this all-position welding is determined by the material of the pipe body to be welded, the groove shape, Since the thickness of the workpiece varies depending on the thickness of the workpiece, experimental welding is performed on the workpiece before actual welding, and the welding of the pipe to be welded is performed based on this experimental data.

On the other hand, a large number of welding setting parameters are added to the experiment for selecting appropriate welding conditions in the above-mentioned experimental welding, which consumes a lot of welding time and makes it difficult to perform urgent welding, making it difficult to improve welding work efficiency. difficult to do.

This type of automatic welding apparatus that has already been proposed is constructed as shown in FIG.

That is, in FIG. 5, a welding carriage a is provided at a part of the welded part of the pipe to be welded, and a drive device and a welding #S power supply C are connected to this welding carriage a, and the welding part rAC is connected to the welding carriage a. A welding torch (not shown) is connected to the welding torch, and a control device d is connected to the welding torch. Furthermore, a welding parameter setting device e, a welding parameter storage device f, and an interface q are connected to and arranged in this control bag @d in this order.

Therefore, the automatic welding apparatus described above previously sets and inputs the only welding parameter obtained in the appropriate welding condition selection experiment to the welding parameter setting device e.

Then, the data of this welding parameter setting device e is stored in the welding parameter storage device f. On the other hand, when the welding start switch attached to the control device d is pressed, the data stored in the welding parameter storage device f is outputted to the welding power source C and drive device of the welding traveling truck a through the interface q. Based on this, the welding torch welds the pipe to be welded with a filler metal welding material.

In this way, in the automatic welding device described above, the welding parameters are (1) depending on the material, wall thickness, etc. of the pipe to be welded.
It is necessary to set the welding current, (2) welding speed, (3) voltage, (4) filler metal feed amount, etc. in advance.

On the other hand, if the arc length of the welding torch is too long during welding of the pipes to be welded, the arc column will spread, the heat input will be over a wider area than necessary, and the heat input to the parts necessary for welding will be reduced.

On the other hand, if the welding arc length is too short, there are drawbacks such as the electrode of the welding torch coming into contact with the workpiece, resulting in unstable welding.

Therefore, in order to obtain a proper arc length, it is necessary to set a welding voltage that is related to the arc length in accordance with the welding current, the orientation of the welding torch, the amount of filler metal fed, and the like.

As described above, in the above-mentioned automatic welding equipment, these welding parameters must be adjusted each time during experiments to select appropriate conditions, and handling operations are complicated.
There are disadvantages such as increased errors due to individual differences and a large amount of time.

[Purpose of the invention]

In order to solve the above-mentioned difficulties, the present invention sets and inputs all welding parameters according to the welding conditions (data) of various pipes to be welded to a welding parameter setting device, stores them in a memory device, and stores them in a memory device. The central processing unit calculates the input data of the welding machine, and automatically controls the arc length and posture of the welding torch on the traveling trolley through each D/A converter and A/D converter. An object of the present invention is to provide an automatic welding device whose purpose is to automatically perform welding suitable for a welded pipe body.

[Summary of the invention]

The present invention provides a welding truck equipped with a welding torch and a filler metal supply device that moves while rotating around a welded portion of a pipe to be welded, and a welding power source and a control device are connected to the welding truck, This control device is constructed by connecting a welding parameter setting device, a memory, a central processing unit, a D/A converter, and an A/D converter, respectively.

(Example of the invention) Hereinafter, the present invention will be described with reference to an illustrated embodiment.

In FIGS. 1 to 4, reference numeral 1 indicates a plurality of jigs 1a.
The guide rail is a ring-shaped guide rail having a ring shape, and a pipe body W to be welded is horizontally fixed to each of the jigs 1a, and a welding cart (welding traveling cart) is mounted on the guide rail 1. 2 moves while turning around the welded portion of the tube W to be welded. In addition, this welding cart 2 has
A well-known welding torch 3 and a filler metal supply V device 4 for supplying filler metal (welding material) are attached.
The electrode 3a of this welding torch 3 is capable of welding the welded portion while burning an arc. Furthermore, a welding power source 4 and a control device 5 are connected to the welding cart 2, and a hand operation 16 is connected to the control device 5.

On the other hand, the control device 5 includes, as shown in FIG.
a welding parameter setting device 7 for setting and displaying welding parameters; a memory 8 for storing a function for calculating a welding voltage from the welding parameters and welding conditions;
A central processing unit 9 for setting data and calculating data, a first D/A converter 10 connected to the welding current circuit 4a of the welding power source 4, and a power amplifier 11 connected to the traveling motor 2a of the welding cart 2. The Δ
/D converters 13 are provided respectively.

On the other hand, as shown in FIG.
An AM region F48a and a ROM region 8b are formed separately, and this RAM region 8a has, for example, a basic current r.
, basic welding speed F. Functions such as are stored.

Further, the ROM area 8b contains, for example, voltage correction terms f (P), f (P,, )・f depending on the welding posture.
(P, ) Voltage correction term g due to MiFiller metal supply amount
Constants such as (Wl)1g(W2), . . . Q(Wn), and voltage correction terms C, C, C3 . . . Cn depending on the groove shape are stored. That is, in the RAM area 8a,
Appropriate welding current, speed, etc. for bead-on-plate, non-filler, and downward position are stored in advance by the welding parameter setting device.

In general, T,1. It is known that in G welding, welding current and welding voltage have a relationship such that a characteristic line I is drawn, as shown in the voltage-current graph of FIG. Furthermore, when the welding position of the welding torch 3 is upward or upward, the welding metal is placed in front of the welding position, and the arc cannot be properly arced at the same current unless the voltage is higher than when the welding metal is moved downward. You can't get long. On the other hand, when feeding a filler wire, the filler wire and molten metal are inserted into the arc column, so compared to non-filler, the voltage must be higher at the same current to obtain an "appropriate apparent arc length." Also, like the first layer welding between Y-shaped beams,
When welding narrow areas, it takes longer to weld than when welding flat areas.
The arc creeps up to the electrode more often, and the appropriate apparent arc length cannot be obtained unless the voltage is adjusted to a certain degree with the same current.

In this way, depending on the welding conditions, even if the current is the same,
If the voltage is not set properly, there are disadvantages such as short circuit between the workpiece (base material) or filler wire and the electrode, or the arc length is too long and the heat input cannot be effectively applied to the desired location. .

In the present invention, paying attention to the above-mentioned circumstances, the welding voltage is calculated based on the following equation (1), and this is stored in the memory device 8 in advance.

V=a, I+b+f (P)+(:J (W)+c...
・・・・・・・・・(1) However, ■ is the welding voltage, I is the welding current, and a.

b is a constant determined by a welding experiment of a flat part with a downward non-filler (see Figure 3).

f (P) is a correction term that takes the welding posture into consideration, and C is a correction term that takes the groove shape into consideration.

Therefore, as shown in FIG.
, b is a specific constant a corresponding to the material of the pipe W to be welded,
It is stored in advance as bo. On the other hand, the welding posture detection device for the traveling carriage 2] 2b is the A/D converter 13.
, a correction term f (P) determined according to the attitude data P taken into the control device 5, and a preset filler metal feed ff1W. A correction term q(W) determined according to is read out from the ROM area 1*8b. Further, by using a selection button on an operation panel (not shown), a correction term C1 corresponding to the groove shape is read out from the ROM area 8b and stored in the RAM area 8a.

Hereinafter, the effects of the present invention will be explained. Note that the present invention is for selecting appropriate welding parameters for each posture of a welded pipe body W as a fixed pipe for which there is no welding experience, and in particular,
This section explains how to select conditions for backing paper welding, which is difficult to select.

First, in a downward position where conditions can be easily selected, the current-voltage that will give the appropriate arc length is reduced by 2. As a result, the above formula (1
), and calculate the constants a and b of the memory device 8 shown in FIG.
a in the OM area 8b. .

Save as bo.

Next, two sets of current-voltage that will give an appropriate arc length are determined for several arbitrary points on the circumference of the tube W to be welded. Therefore, the difference from the proper condition for the downward posture is calculated from welding posture P1 to
The correction terms f(Pl) to f(P, ) in P are stored in the ROM area 8a of the storage device 8 shown in FIG. In addition, this memory 8 stores correction terms a(Wl) to g(W,
) is stored in the ROM area 8b. moreover,
The differences from the double-on plate welding conditions when welding the inside of the groove are stored in the ROM area 8b as 01 to C6. In this way, after these preliminary experiments are completed, the appropriate welding conditions for the tube body W to be welded as an actual fixed tube are selected.

Next, set the appropriate welding current and speed for bead-on-plate, non-filler, and downward position using the welding parameter setting bag U.
7 manually using keys not shown in the figure. Further, the central processing unit 9 stores the data from the welding parameter setting device 7 in the RAM area 8a of the storage device 8 as I and Fo. Then, as shown in FIG. 1, the welding cart 2 and the welding cart 2 are moved to the starting position using a cart running switch (not shown) on the hand control panel 6. Next, by pressing a welding trajectory switch (not shown), welding is started using the electrode 3a of the welding torch 3.

In this case, the detection signal from the welding posture detection device 2b on the welding cart 2 is converted into a digital quantity by passing it through the A/D converter 13, and the correction term f (P) is generated in the central processing bag H9. is calculated, and the RAM area 8a of the storage device 8
stored within.

On the other hand, the filler metal feed amount W is set in advance by the welding parameter setting device 7.

A correction term C and constants a and b corresponding to the type of groove are stored, and the central processing bag @9 calculates the current I based on the above equation (1). and the welding voltage corresponding to the welding conditions at that time■.

is calculated. This calculated value is then output as a voltage target value to the first D/A converter 10 and the twentieth/A converter 12, respectively. Also, when the welding cart 2 travels on the circumference of the pipe W to be welded and the welding posture changes, or while observing the Uranami welding state, the operator operates the current adjustment switch on the hand control panel 6. When increasing or decreasing the welding current or adjusting the feed amount using the filler metal feed amount adjustment switch (not shown), the welding voltage ■ is calculated using the above-mentioned procedure.
It is designed to be output as a voltage target value.

In this way, the present invention allows welding parameters to be set by the welding parameter setting device 7 according to welding conditions for various types of welded tubes W.
The settings are inputted and stored in the memory 8, and the central processing unit 9 automatically performs welding appropriate for the pipe W to be welded based on the input data of the memory 8.

〔Effect of the invention〕

As described above, according to the present invention, in the welding cart 2 equipped with the welding torch 3 and the filler metal supply device 4 that move while rotating around the welding part of the pipe W to be welded, welding is performed on the welding cart 2. A power source 4 and a control device 5 are provided, and the control device 5 includes a welding parameter setting device 7, a memory device 8, a central processing device 9, and each D/A converter 10, 12 and A.
Since the /D converters 13 are connected to each other, it is possible to always obtain the appropriate arc length, which not only simplifies the process of selecting appropriate conditions, but also eliminates errors and operational errors due to individual differences. Therefore, welding work efficiency can be improved.

[Brief explanation of the drawing]

Fig. 1 is a diagram of an automatic welding device according to the present invention, Fig. 2 is a block diagram of a control device incorporated in the present invention, and Fig. M3 is a diagram for explaining a memory used in the control device. , FIG. 4 is a graph showing the relationship between welding current and voltage, and FIG. 5 is a block diagram of an already proposed automatic welding device. DESCRIPTION OF SYMBOLS 1... Guide rail, 2... Welding trolley, 3... Welding torch, 4... Welding power source, 5... Control device, 7...
... Welding parameter device, 8... Memory device, 9... Central processing unit, 10... First D/A converter, 12...
20th/A converter, 13th... A/D converter. Applicant's agent Kiyoshi Inomata Figure 1 Figure 4 Figure 5

Claims (1)

[Claims] 1. A welding truck equipped with a welding torch and a filler metal supply device that moves while rotating around the welded portion of the welded tube, in which a welding power source and a control device are connected to the welding truck. A welding parameter setting device is provided in this control device,
An automatic welding device characterized in that a memory device, a central processing unit, each D/A converter, and an A/D converter are connected to each other. 2. The automatic welding apparatus according to claim 1, wherein the memory stores welding parameters for various pipe bodies to be welded.