JPS5912387B2 - Method for welding a reinforcing ring provided on the inner peripheral surface of a cylindrical body - Google Patents

Description

Detailed Description of the Invention - 5 The present invention relates to a welding method for attaching a reinforcing lip cover to the inner circumferential surface of a cylindrical body, and in particular to a dolly that moves by itself along the inner circumferential surface of a rotating cylindrical body; A tilt detection device is installed in a part of the welding equipment consisting of a torch and a torch that performs fillet welding around the entire circumference of the covering body in an almost downward position. It is designed to increase or decrease the running speed.

Conventionally, when welding the inner peripheral surface of a cylindrical body, welding is performed in a downward position.

That is, the cylindrical body is placed on a turning roller rack 5 and rotated in one direction, and the welding device is inserted into the cylindrical body from the outside and fixed therein, or is placed inside the cylindrical body and is mounted on a self-propelled trolley. will be installed on. For example, as shown in FIG. 5, when attaching the reinforcing cover 2 to the inner surface of the cylindrical body 1, the cover 2
is fillet welded to the inner circumferential surface of the circular cylindrical body 1. During welding, the cover 2 is temporarily attached to a predetermined position within the cylindrical body 1, and the cylindrical body 1 is placed on a turning roller device and rotated. Further, the welding device 3 is provided at the tip of the pulley 35 extending from the manipulator 4, as described above and illustrated in FIG. Welding is performed by rotation 6. By the way, welding using such a welding device supported by a boom not only requires large-scale equipment and is uneconomical, but also requires a perfect circle holder for the cylindrical body 1, as shown in FIG. 7 has the disadvantage that it is impossible to insert a pool.

Therefore, fillet welding of the reinforcing ring inside the cylinder often relies on manual welding, which requires a large number of man-hours, increases welding costs, and does not provide uniform welding. The present invention has been made with attention to these points, and in particular, when fillinget welding the reinforcing ring 2 to the inner circumferential surface of the cylindrical body 1, the reinforcing ring 2 travels along the inner circumferential surface of the cylindrical body 1, and the traveling speed is In addition to using a dolly that can be increased or decreased, a slope detection device is installed in a part of the welding equipment including the dolly to detect the degree of inclination in the direction of welding progress, and the running speed of the dolly is increased or decreased based on this detection. It is. The present invention will be explained in detail below based on the drawings, but the drawings show one example of a specific implementation, and the present invention is not limited to the case where the illustrated example device is used. It can be carried out in the same way using a welding device of.

-Generally, in automatic welding of the inner circumferential surface of a cylindrical body, a cart carrying a welding device runs in the opposite direction to the rotational movement direction of the cylindrical body, and the welding speed is set depending on the welding conditions.At the same time, a turning roller Determined by the rotation speed of the device.

Furthermore, when the trolley is running, it is necessary to perform welding under certain conditions in a downward position, and the torch must be maintained at a constant position relative to the ground. Therefore, the speed of the cart is usually adjusted visually according to the rotational speed of the turning roller, which requires constant monitoring and is extremely inaccurate. By the way, when fillet welding the reinforcing ring 2 to the inner circumferential surface of the cylindrical body 1 as described above, welding is generally performed on an uphill slope in order to improve the appearance of the bead, and the torch is attached to the cylindrical body. It is set to be inclined in the direction of welding progress from the center perpendicular of 1.

The distance between the intersection of the perpendicular lines on the welding line and the torch pointing point on the same welding line is generally called the eccentric distance, and unless this distance is maintained properly, good welding cannot be achieved. q
In addition, the eccentric distance varies depending on the welding conditions and is determined by looking at the actual shape of the welded part. Even if the angle of inclination of the torch is specified in advance, it may be necessary to change the inner diameter of the cylindrical body, etc. It is required to be able to adjust to Note that as a control means for these, a control device may be provided for each of the turning roller drive device and the trolley drive device and a means for linking them to each other may be used, but the control is based solely on relative speed; Corrections due to slips, abrasion, etc. of the drive roller were necessary and were not satisfactory. Therefore, the present invention provides an angle detector that detects the inclination of the torch during fillet welding in a downward position as described above. is fixed to a part of the welding equipment, and this detector is used to increase or decrease the traveling speed of the trolley, thereby maintaining the torch of the welding equipment at a predetermined position relative to the ground.〇Figure 2 shows 3 is a left side view of FIG. 2, FIG. 4 is a control block diagram, and FIGS. 6 and 7 are fillet welding equipment. It is an explanatory diagram.

In these figures, the welding device suitable for carrying out the present invention is a submerged arc welding device that is also equipped with a flux dispersion and recovery device, and is equipped with multiple torches that simultaneously perform fillet welding on both sides of the ring body 2. be. That is, the welding device 3 is mounted on a truck 9, and the truck 9 is provided with running wheels 8, 8 at the front and rear, respectively.
. Further, the trolley 9 is provided with a tracing roller 10, which runs to trace the temporarily attached ring body 2, and has two sets of welding heads, each of which directs a torch 12, 12' toward the fillet weld. Provided. 11 indicates a torch copying roller.

Reference numeral 13 denotes a flux hopper, which has a dispersion port opened in the forward direction of the welding direction of each torch 12, 12', and a collection port 14 provided in the opposite rear direction. A tilt detector 21 as shown in FIG. , a spirit level type, a ball rolling type, etc. are used, and these inclination displacements are detected optically or electrically, and the electric signal is inputted to a control device in the drive device of the truck 9. FIG. 4 is a block diagram showing these controls. Reference numeral 15 indicates the control drive motor of the truck 9, and a rotational speed generator 16 is connected to the drive motor 15.

Reference numeral 17 denotes a controller for the drive motor 15, which receives a signal from the generator 16 and a signal from the comparator 18 to drive the drive motor 15 under control.

The inclination detector 21 detects the inclination in the welding progress direction of the torches 12, 12', which are integrally constructed with the truck 9 or the welding device, and sends a signal to the amplifier 19 to maintain the set inclination. The signal is amplified and input to the comparator 18.
Reference numeral 20 denotes an inclination angle setting device, and a desired angle of inclination of the carriage, that is, a torch pointing position within the cylindrical body can be set by means of a polyurethane.

The comparator 18 also includes a tilt angle detector 21 and a tilt angle setter 2.
0 signals are compared and a command is given to the controller 17 for the truck and drive motor. When the turning roller device 6 is started, the truck 9 is also started, and is driven while maintaining the set inclination relative to the ground, that is, the position relative to the ground. Therefore, the welding speed (relative speed between the cylindrical body 1 and the carriage 9) can be easily determined and accurately maintained by independently setting the rotation speed of the turning rollers. Of course, the rotation of the turning roller is maintained at a constant speed by conventionally known independent control means. Furthermore, the torches 12 and 12' explained in FIG. It is also possible to perform fillet welding by increasing the eccentric distance. As an example, FIG. 7 shows a case in which the torch 12' is placed in the lead, and by changing the eccentric distance from each other in this way, it is possible to prevent the formation of weld pits, especially when working with steel plates that are prone to rust. Moreover, it is preferable that these eccentric distances have a difference of 50 mm to 200 mm. As for the welding method, submerged arc welding is preferred as described above, but automatic or semi-automatic welding methods such as MIG welding and carbon dioxide welding can be used if necessary.Furthermore, the welding device 3 is also mounted entirely on the trolley 9. However, it is also possible to use a structure in which the welding head C is mounted on a truck, and the wire reel and control device are supported on another truck or boom. As described above, when fillet welding a reinforcing ring to the inner circumferential surface of a cylindrical body, the present invention provides a welding torch on a traveling bogie and a torch inclination angle detector on a part of the bogie or the mounted welding device. is provided, and the running speed of the truck is controlled to increase or decrease based on this detection, so the efficiency of fillet welding can be dramatically improved and a good fillet weld can be obtained.

[Brief explanation of the drawing]

Figure 1 is an explanatory cross-sectional view of fillet welding on the inner peripheral surface of a cylindrical body, Figure 2
3 is a left side view of FIG. 2, FIG. 4 is a block diagram showing a control means,
Fig. 5 shows an example of a cylindrical body to which the present invention is applied, an explanatory diagram showing the annular body by breaking the cylindrical body, Fig. 6 is a plan view of a fillet weld, and Fig. 7 shows another example of arrangement. FIG. 1... Cylindrical body, 2... Annular body, 3...
... Welding equipment, 4... Manipulator, 5...
...Boom, 6...Turning roller device, 7...Holder, 8...Travelling wheel, 9
...Dolly, 10, 11 ... Copying roller, 12 ... Torch, 13 ... Flux hopper, 14 ... Collection pipe, 15. ...
...Bogie drive motor, 16...Rotary generator, 1
7...Controller, 18...Comparator, 19
......Amplifier, 20......Inclination angle setting device,
21... Tilt angle detector.

Claims (1)

[Claims] 1. A method of welding a reinforcing cover to the inner surface of a cylindrical body, the cylindrical body to which the reinforcing cover is temporarily attached is placed on a turning roller device and rotated, and the inner surface of the cylindrical body is welded. The welding device disposed in the cylindrical body consists of a cart that moves by itself along the inner circumferential surface of the cylindrical body, a torch mounted on the cart so as to perform fillet welding of the reinforcing cover in a substantially downward position, and further The welding device is provided on the inner circumferential surface of the cylindrical body, characterized in that the welding device is provided with a device for detecting the degree of inclination of the cart with respect to the direction of gravity, and the traveling speed of the cart is increased or decreased based on a signal from the detection device. Welding method for reinforcing cover. 2. The welding method according to claim 1, wherein the welding device is a submerged arc welding device equipped with a flux dispersion mechanism and a collection mechanism. 3. In claim 1 or 2, fillet welding is a welding method in which fillet welding is performed simultaneously on both sides of the reinforcing cover using a plurality of torches arranged to face the fillet welds on both sides. 4. The welding method as set forth in claim 1 or 2, in which the fillet welding torches are directed one at each side of the fillet welding portion of the reinforcing cover, and one torch is placed in the lead on one side. 5. The welding method according to claim 1, 2, 3 or 4, wherein the torch is aimed at an uphill slope.