JPH0144228Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention is a circumferential automatic welding machine that welds circumferential joints of pipes, and in particular, a circumferential automatic welding machine for welding circumferential joints of pipes. It relates to a gas shield chamber for protection.

Conventionally, this type of welding machine has been shown in FIG. 1 or 2. In the conventional welding head shown in FIG. 1, 1 is a welding head having an inner hole corresponding to the outer circumferential surface of the welded material 2, and 3 is an inner hole supported on the welding head 1 and corresponding to the outer circumferential surface of the welded material 2. A driving ring 4 is rotatable relative to the welding head 1 along the periphery of the welding head 1, and 4 is fixed to the driving ring 3 with fixing screws 5, 6.
7 is a welding torch adjustment for attaching a welding torch 8 which is arranged so as to rotate on the outer peripheral surface of the workpiece 2 together with the drive ring 3 via the mounting plate 4 via an insulating plate 9. The welding torch adjustment mechanism 7 is a mechanism capable of adjusting the aiming position of the welding torch 8 during welding, and is fixed to the mounting plate 4. 10 is a nozzle which is attached to the welding torch 8 and is a shielding gas outlet for protecting the welding part from the atmosphere, and 11 is an electrode which is an arc generating point during welding.

In addition, in the conventional one shown in FIG. 2, the welding head 1 is supported by a welding head having an inner hole corresponding to the outer circumferential surface of the welded material 2 and runs along the periphery of the inner hole corresponding to the outer circumferential surface of the welded material 2. A drive ring 9, which can rotate relative to the welding head 1, is fixed to the inner circumference of the drive ring 3 and insulates the workpiece 2 and the drive ring 3. An insulating ring 11 serves as a shielding gas chamber for protecting the welding material, and an electrode 11 serves as an arc generation point during welding.

Next, the operation of the conventional welding machine shown in the figure will be explained. A welding head 1 is fixed onto the outer periphery of a workpiece 2 to be welded. Then, connect the drive ring 3 to the welding head 1.
The welding material is rotated on the outer periphery using a drive mechanism. When the drive ring 3 rotates on the outer periphery of the welded material 2, the electrode fixed to the welding torch 8 held on the outer periphery of the welded material 2 via the mounting plate 4, the welding torch adjustment mechanism 7, and the insulating plate 9. 11 and the nozzle 10 are also rotated to perform welding.

Conventional circumferential automatic welding machines are configured as described above, so in the circumferential automatic welding machine shown in Fig. 1, if only the nozzle is shielded, only the welding area is shielded, and the heated weld bead after welding is Metals that are easily oxidized when heated, such as stainless steel and titanium, are oxidized during welding, resulting in unstable welding quality. Although the circumferential automatic welding machine shown in Fig. 2 eliminates the drawbacks mentioned in Fig. 1, it is difficult to position the welding line when gripping the welding head 1 on the workpiece 2 because the weld line cannot be seen by the drive ring. be.

This idea was made in order to eliminate the above-mentioned drawbacks of the conventional method, and it includes a nozzle and prevents the shielding gas, which is ejected from the nozzle and protects the welded part from the atmosphere, from dispersing into the atmosphere.
By providing a ring-shaped gas shield chamber that covers the weld line on the outer circumferential surface of the workpiece and is detachable from the radial direction of the workpiece, the gas is emitted from the welding torch nozzle and protects the weld from the atmosphere. The shielding gas is guided over the outer periphery of the weld line of the welded material and heated, protecting the weld bead from the atmosphere and improving welding quality. It is an object of the present invention to provide a circumferential automatic welding machine that can be made visible by opening the shield chamber, thereby improving accuracy and significantly stabilizing welding quality.

An embodiment of this invention will be described below with reference to the drawings. In FIGS. 3 and 4, 1 is a welding head having an inner hole corresponding to the outer circumferential surface of the welded material 2, and 3 is a welding head supported by the welding head 1 and having an inner hole corresponding to the outer circumferential surface of the welded material 2. A drive ring 4 is rotatable relative to the welding head 1 along the periphery; 4 is a drive ring 3;
A mounting plate 7 is fixed to the mounting plate 4 with fixing screws 5 and 6, and a welding torch 8, which is arranged so as to rotate on the outer circumferential surface of the workpiece 2 together with the drive ring 3, is connected to the mounting plate 4 via an insulating plate 9. Welding torch adjustment mechanism for installation,
The welding torch adjustment mechanism 7 is a mechanism capable of adjusting the aiming position of the welding torch 8 during welding, and is fixed to the mounting plate 4. 10 is a nozzle that is attached to the welding torch 8 and is a shielding gas outlet for protecting the welding part from the atmosphere, and 12 is a nozzle that is ejected from the nozzle 10 to protect the welding part from the atmosphere so that the shielding gas does not diffuse into the atmosphere. The gas shield chamber has a structure that can be opened with hinges 12a and 12b, and a latch 12c.
It has a structure that holds it in a ring shape,
The weld bead formed on the weld line on the outer peripheral surface of the material to be welded 2 and heated during welding is protected from the atmosphere and prevented from blending with the atmosphere, thereby significantly improving welding quality. Reference numeral 11 denotes an electrode that serves as an arc generation point during welding.

In the above configuration, the welding operation is basically the same as the conventional one, so it will be omitted. The additional point is that the opening of the gas shield chamber must be opened and installed while visually checking the position of the weld line, and then the opening of the gas shield chamber must be closed again.

As described above, according to this invention, a ring-shaped gas shield chamber that can be opened includes a nozzle that is a shield gas outlet that protects the welding part from the atmosphere, and also covers the outer periphery of the weld line of the welded material. Since it is placed on the outer periphery of the weld line, the shielding gas ejected from the nozzle is effectively used to heat and blend easily with the atmosphere, protecting the weld bead from the atmosphere and producing welding results with significantly improved welding quality. In addition, the accuracy of aiming and positioning the welding line when the welding head is attached and fixed to the workpiece to be welded can be visually improved by opening the gas shield chamber, and the welding quality can be stably improved.

[Brief explanation of the drawing]

Figure 1 is a plan view showing a conventional circumferential automatic welding machine.
Fig. 2 is a partially sectional plan view showing another conventional circumferential automatic welding machine, Fig. 3 is a plan view of a circumferential automatic welding machine according to an embodiment of this invention, and Fig. 4 is its front view. . In the figures, the same reference numerals indicate the same or equivalent parts, 1 is the welding head, 2 is the material to be welded, 3 is the drive ring, 4 is the mounting plate, 5 and 6 are fixing screws, 7 is the welding torch adjustment mechanism, and 8 is Welding torch, 9 is an insulating plate,
10 is a nozzle, 11 is an electrode, 12 is a gas shield chamber, 12a and 12b are hinges, and 12c is a latch.

Claims (1)

[Scope of utility model registration request] a welding head having an inner hole corresponding to the outer peripheral surface of a rod-shaped material to be welded; a drive ring supported by the welding head and rotatable relative to the welding head along the periphery of the inner hole; A circumference having a welding torch carried by a drive ring, a welding torch adjustment mechanism, and a centering device disposed in the inner hole of the welding head and engaging the outer peripheral surface of the workpiece to grip the front and rear workpieces. The automatic welding machine includes a shielding gas outlet for protecting the welding part of the welding torch from the atmosphere, as well as a shield gas spouted from the nozzle to protect the welding part from the atmosphere, so as not to diffuse into the atmosphere. Equipped with a ring-shaped gas shield chamber that covers the weld line on the outer peripheral surface of the welding material,
This gas shield chamber is a circumferential automatic welding machine in which a part of the circumferential direction of the gas shield chamber is formed separately, and the separate parts are connected by a hinge so that the gas shield chamber can be opened at this part.