JPH0735000B2 - Pipe welding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is suitable for automatic welding work in a narrow space in welding of a fixed pipe in which the pipe cannot be rotated during welding. The present invention relates to a pipe welding device.

[Conventional technology]

Conventionally, the TIG (Tungsten-iner) is the part that requires high quality in all-position all-position welding of fixed pipes (hereinafter referred to as pipes).
t-gas) welding, and the plasma keyhole welding method was not applied.

As an apparatus for welding a pipe, for example, Jikkou Sho 59-422
The one described in Japanese Patent No. 18 is cited.

[Problems to be solved by the invention]

When pipes are welded all around by TIG welding, there is a problem in that work efficiency is poor because it is necessary to carry out multi-layer welding except for very thin pipes.

On the other hand, when the plasma keyhole welding method is used, the work efficiency can be improved because the single layer welding can be performed on the medium thick plate or less, that is, about 4 mm or less in thickness.

However, since there is a large amount of molten metal at the time of welding, there is a risk that molten metal will fall down on the lower side of the pipe, and the plasma keyhole welding method was not applied to all-around all-position welding of the pipe.

When applying the plasma keyhole welding method to the pipe, the processing of the cables and hoses connected to the welding torch and the welding start position are at approximately 4:30 on the clock display, so the welding head body is attached to or detached from the pipe. There were problems such as difficult work.

An object of the present invention is to provide a pipe in which welding can be automatically started regardless of the angle at which the welding head main body is attached to the pipe in all-around all-position welding of the pipe, and the welding head main body can be immediately removed after the welding is completed. It is to provide a welding device.

[Means for solving problems]

The above-mentioned object is provided with a rotating gear having an opening for enabling attachment / detachment to a pipe and a welding torch installed on the rotating gear, and the welding torch rotates around the pipe to perform the entire circumference welding. In a pipe welding apparatus, the rotary gear, a drive device for driving the rotary gear, a gear that transmits a driving force from the drive gear to the rotary gear, and the welding torch are mounted, and an opening of the rotary gear is installed. A welding head having an opening that substantially coincides with the portion, an angle detection device that automatically detects the inclination angle of the welding head body inserted at an arbitrary angle with respect to the pipe, and the angle detection device. The welding start position is calculated by inputting the tilt angle, the predetermined welding start position and the detachable position information of the welding head body with respect to the pipe, and the position after welding is completed and the rotation amount to the welding head detachable position is calculated. And it is accomplished by providing, a condition control device for controlling the welding machine and the driving machine to provide a welding condition to the welding torch on the basis of the calculation results.

Further, in the apparatus having the above configuration, the condition control device is
During plasma keyhole welding, control of the pulse current to the welding machine and the welding start position of the welding torch are displayed on the clock 3
You may make it control so that it may become the range from 6:00 to 6:00.

[Action]

With the introduction of the microcomputer for the welding condition controller, a great deal of automation became possible. On the other hand, given the welding method, joint shape, etc., the welding start position at which good welding can be performed is determined. Therefore,
If the positional relationship between the welding head body and the rotating gear during attachment / detachment is always set to a fixed stop position (for example, a convenient position for attachment / detachment), the tilt angle of the welding head body at the time of attachment to the pipe is input to the controller. Simply, the torch automatically moves to the welding start position for welding.

In plasma keyhole welding, welding progresses while a hole called a keyhole is opened during welding by the jet force of the arc. Therefore, at the start of welding, defects are likely to occur until a stable keyhole is formed. Further, since the welding start portion is overheated, when the keyhole is formed, the molten metal is likely to be burned down.
With respect to such a problem, when welding is started in a downward posture, the molten metal can be prevented from being burned down by the action of gravity.

Further, in the entire circumference welding of the pipe, the welding start position and the end position overlap with each other. Then, at the end, a process of closing the keyhole that has been formed until then is necessary. For that purpose, a posture in which the molten metal hangs down on the surface of the pipe, that is, a posture from downward to upward is preferable. From the above results, it is appropriate that the welding start position in plasma keyhole welding be in the range from 3 o'clock on the clock display to 6 o'clock in the downward welding posture.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, it is impossible to rotate the pipe by welding the entire circumference of the bent pipe 1. In view of this, in the present apparatus, the welding head body 3 having the opening 2 is also provided with the rotating gear 6 having the opening 4 and the welding torch 5 mounted thereon, and the gear 7 is arranged as shown in FIG. 11 to 11 and the opening 2 of the welding head main body 3 and the opening 4 of the rotary gear 6 are aligned with each other, the chuck mechanism 12 attaches and detaches to and from the pipe 1, and either of the gears 7 or 8 Rotational drive is possible by engaging one of them. Here, the welding head body 3 and the rotary gear 6 are coupled by a groove structure that smoothly rotates and does not separate at the opening. A welding machine 13 is connected to the welding torch 5, and a drive machine 14 rotates the pipe 1 around the pipe 1. In this embodiment, the inclination of the welding head body 3 is detected by the angle detector 15 and input to the condition control device 16, but the position performed by another method may be input to the control device 16.

Next, the operation will be described with reference to FIGS. The indications at 12, 3, 6, and 9 o'clock in the figure describe the position of the welding torch with respect to the pipe 1 using the dial plate display of the clock. When the torch rotates in the same direction as the clock and welding progresses, downward welding is performed at 12:00, vertical downward movement at 3:00, upward movement at 6:00, and vertical upward welding at 9:00.

Further, the solid line in the figure represents the operation of the torch while welding, and the broken line represents the movement of the torch before and after welding. In the example of FIG. 3, it is assumed that the welding head body 3 and the rotary gear 6 are inserted into the pipe 1 from the point in a state where the openings 2 and 4 of the welding gear body 3 coincide with each other. Here, assuming that the welding start position is set to a range from 3 o'clock to 6 o'clock and a point (approximately 4:30 position) is set, the difference between the point and the point from the inclination angle of the main body 3 detected by the detector 15. When the welding start signal is given and a welding start signal is given, the welding torch 5 automatically moves to the point, and then makes one round from the point to weld to the point. Then welding torch 5
Reversely moves to a point where the welding head body 3 can be detached. FIG. 4 shows an example of the case where the welding head main body is inserted from another different angle, and the operation of →→→ is the same as the case of FIG.

〔The invention's effect〕

As described above, according to the present invention, if the welding start position (the position of the welding torch) is set, no matter what angle the welding head body is inserted into the pipe and the welding head is automatically attached, In addition, the welding torch can be moved in a predetermined motion to advance the welding, and even after the welding is completed, the state can be restored to the state at the time of mounting.
Also, since the cables connected to the welding torch do not wind around the pipe, it is possible to take out the welding head main body from the pipe immediately, improving operability and efficiency, and welding especially in narrow spaces. The effect is great when there are restrictions on the attachment / detachment of the head body.

[Brief description of drawings]

1 to 4 are explanatory views of the embodiment of the present invention, FIG. 1 is a side view of the embodiment, FIG. 2 is a front view of the embodiment, and FIG. 3 is an operation explanatory view of the embodiment. The figure is an operation explanatory diagram when used in a state different from that of FIG. 1 ... pipe, 2 ... opening (main body), 3 ... welding head main body, 4 ... opening (rotating gear), 5 ... welding torch, 6 ... rotating gear, 7,8,9,10 , 11 …… Gears, 12 …… Check mechanism, 13 …… Welding machine, 14 …… Driving machine, 15 …… Angle detector, 16 …… Condition control device.

Front Page Continuation (72) Inventor Takeshi Yamade 3-1-1 1-1 Saiwaicho, Hitachi City, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Fumizo Ando 3-20-12 Takanawa, Minato-ku, Tokyo Within Japan Welltec Corporation (56) Reference JP-A-57-132770 (JP, A) JP-A-60-121077 (JP, A)

Claims (2)

[Claims] 1. A rotary gear having an opening for enabling attachment / detachment to / from a pipe, and a welding torch installed on the rotary gear, wherein the welding torch rotates around the pipe to perform full circumference welding. In the pipe welding apparatus to perform, the rotary gear, a drive machine for driving the rotary gear, a gear for transmitting a driving force from the drive machine to the rotary gear, and the welding torch are mounted, and the rotary gear A welding head having an opening that substantially coincides with the opening, an angle detection device that automatically detects the inclination angle of the welding head body inserted at an arbitrary angle with respect to the pipe, and the angle detection device. The welding start position is calculated by inputting the inclination angle, the predetermined welding start position and the welding head main unit detachable position information for the pipe, and the rotation amount to the position after welding completion and the welding head detachable position is calculated. , The calculation and condition control device for controlling the drive machine and welding machine to provide a welding condition to the welding torch on the basis of the result, comprising a pipe welding apparatus. 2. The pipe welding apparatus according to claim 1, wherein the condition control device controls the pulse current to the welding machine during plasma keyhole welding and displays a welding start position of the welding torch with a clock. The pipe welding apparatus is characterized in that it is controlled so that it is in the range from 3:00 to 6:00.