JPH0736927B2 - Welding roll for metal pipes - Google Patents

Description

TECHNICAL FIELD The present invention relates to a welding roll for metal pipes.

[Prior art and its problems]

For example, in order to protect a 0.5 mmφ thin plastic-coated filament from tension, water, etc., or to protect it from heat and stress, this plastic-coated filament is, for example, a metal pipe of 2 to 6 mmφ. It is being housed inside.

However, it is extremely difficult to manufacture a thin and long metal tube and then draw the thin long plastic-coated filamentous body into it. Therefore, it has been practiced to insert a plastic-coated filament in the production of a metal tube. That is, a plastic coated filament is vertically attached to a metal tape made of Al, Cu or the like, and both ends of the metal tape are sequentially abutted from the tip end side so that the plastic coated filament is built into the pipe forming pipe. However, it is manufactured by welding the abutting portions. Such welding is performed by electric welding such as TIG welding.

However, when the amount of metal penetration increases due to electric welding, there is a problem that heat will flow through the metal tube with good thermal conductivity and flow into the plastic-coated filament until the penetration part cools, causing thermal damage. It was

Therefore, the inventor of the present invention has previously proposed the Japanese Utility Model Publication No. 59-35344.
No. 6-74502) discloses a device in which a cooling water passage is provided in a welding roll used when manufacturing a metal tube.

However, although such a device can avoid thermal damage at the time of pipe making, since the welding roll is made of metal, it is not possible to prevent arc discharge generated between the electrode and the welding roll during welding. Therefore, the arc locally damages the welding roll. If this state is left as it is, the welding roll itself is deformed and the life is shortened.

Therefore, welding rolls made of ceramics have also been considered in order to prevent arc discharge.

However, when the welding roll is made of ceramic, it has a high hardness, so that a cooling water passage having a complicated shape cannot be provided inside the welding roll, and a thermal problem associated with welding cannot be sufficiently solved. Also, in order to rotate the welding roll in order to send out the metal pipe at the time of pipe making, a member such as a bearing is fitted inside thereof, but the housing portion of such member is also formed in a predetermined shape because the hardness of the ceramic is high. It is difficult to do so, and it is difficult to get a smooth rotating one.

As a result, it is common practice to use metal tube weld rolls with cooling water passages and replace them with new ones when the arc damage is significant.

However, if the welding rolls are replaced on a regular basis, not only the running-in operation is required each time, but also the readjustment of the operating state such as the so-called correct positioning of the mounting position is required. As a result, there has been a problem that the operating rate of the pipe making equipment is lowered and a high quality metal pipe cannot be stably manufactured.

The present invention has been made in view of the above points, and prevents the occurrence of an arc between the electrode, readjustment of the operating state during pipe making and break-in operation, high-quality metal It is intended to provide a welding roll for a metal pipe, which can stably produce a pipe with a high operating rate.

[Means for solving problems]

The welding roll of the metal pipe according to the present invention is rotatably attached to the surface of the metal tape 11 so that both ends of the metal tape 11 along which the long plastic-coated linear body 19 is vertically attached are abutted. A metal tape is provided, which comprises a roll main body 20 in sliding contact with the butt portion 17 of the metal tape 11 is welded to form a pipe.
In a welding roll of a metal pipe in which 11 is sequentially sent out as a metal pipe in which the long plastic-coated linear body is housed, the roll body 20 has an outer peripheral surface area that is in sliding contact with the metal tape 11 and an outer periphery of the rotating body 7. It is composed of a ceramic ring body 10 which is an insulator fitted to the
It is characterized in that cooling water passages 5c, 5d for flowing the water are provided.

[Action]

According to the welding roll of the metal pipe according to the present invention, the roll body
A surface region of the metal tape 11 which is in sliding contact with the surface of the metal tape 11 is formed of a ceramic ring body 10 as an insulator. Therefore, the portion of the roll body 20 that does not come into contact with the surface of the metal tape 11 has a long distance from the welding electrode, and prevents arc discharge from occurring between the electrode and the welding roll at the time of pipe forming, while performing pipe forming work. It became possible to do it. In addition, since the coolant for flowing in the cooling water passages 5c and 5d provided along the rotating body 7 is welded for pipe making, the rotating body 7 is cooled by the cooling water, and the ceramic ring body is also cooled. 10 will also be indirectly cooled via the rotating body, and the metal tape due to heat during welding
It is possible to prevent the damage of 11 and the thermal deterioration of the plastic coated filament. As a result, the welding roll can be used stably for a long period of time, and a high-quality metal pipe can be manufactured with a high operating rate.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view showing a schematic configuration of an embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II of the same embodiment.

The welding roll of this metal tube is provided with a pair of welding rolls, and the ceramic ring body 10, which is an insulator provided in each roll body 20 described later, is pressed from both sides against the surface of the metal tape 11 which is an untreated body. While sliding and making pipes, metal tape 11
However, in order to simplify the description, only one welding roll is shown, the configuration thereof will be described below, and the illustration and description of the configuration of the other welding roll will be omitted.

In the figure, 1 is a roll seat. On the upper part of the roll seat 1, a shaft 2 that supports the roll body 20 is erected. The shaft 2 is fixed to the roll seat 1 by a fixing nut 3. A rotating body 7 is rotatably fitted to the upper portion of the shaft 2 via a bearing 6. A cooling water supply tube 4 is attached to the roll seat 1. The cooling water supply tube 4 is connected to cooling water passages 5c and 5d for flowing the cooling water 14 along the rotating body 7.

More specifically, the cooling water supply tube 4 communicates with the cooling water passage 5b in the shaft 2 via the cooling water passage 5a in the roll seat 1. The bottom of the rotating body 7 is the shaft 2
It is stored in a cooling water tray 8 formed on the outer periphery of the upper part of the. A cooling water drainage tube 9 is formed in the cooling water receiving tray 8. A ceramic ring body 10, which is an insulator, is fitted around the outer periphery of the rotating body 7. On the outer peripheral surface of the ceramic ring body 10, there is formed a sliding contact groove 12 having a semicircular cross section for bending the surface of the metal tape 11 of the object to be processed into the shape of a target tube.

At the top of the shaft 2, a pressing plate 13 having a cooling water passage 5d for communicating the cooling water passage 5b in the shaft 2 with the cooling water passage 5c in the rotating body 7 is provided. It is attached so as to be clamped and fixed.

The cooling water passage 5c in the rotating body 7 communicates with the cooling water drainage tube 9 via the cooling water receiving tray 8. An O-ring is provided between the holding plate 13 and the rotating body 7 to prevent the cooling water 14 from leaking.
15a is interposed.

A bush 16 is attached to the bottom of the cooling water passage 5b formed in the shaft 2, and the O-rings 15b and 15c are also provided between the bush 16 and the shaft 2 and between the bush 16 and the roll seat 1.
Is intervening. Further, electrodes 18 for welding are provided above the abutting portions 17 on both side ends of the metal tape 11 curved by the sliding contact groove 12.

In addition, 19 in FIG. 1 is, for example, a plastic-coated linear body inserted in the pipe forming portion of the metal tape 11.

The roll body 20 composed of the rotating body 7, the ceramic ring body 10 and the pressing plate 13 has good thermal conductivity (coefficient of thermal expansion is 3 to 8 ×).
It is made of copper alloy so as to suppress the generation of thermal stress at 10 ^-6 (1 / ° C). Further, the ceramic ring body 10 is formed of a ceramic member made of SiC, Si ₃ N _4, or the like, which is an insulator.

According to the metal pipe welding roll configured in this manner, for example, the surface of the metal tape 11 on which the plastic-coated linear body 19 is vertically attached in advance is pressed from both sides by the sliding contact grooves 12 of the pair of ceramic ring bodies 10. Both ends of the metal tape 11 are butted, and a pipe is formed between the butted part 17 and the electrode 18 by, for example, high frequency TIG welding. After pipe making, while rotating the rotating body 7 and the ceramic ring body 10 around the shaft 2 via the bearing 6,
Send out the metal tape 11. At this time, the portion of the roll body 20 close to the electrode 18 is the ceramic ring 10 which is an insulator.
The roll body 20 made of metal is sufficiently separated from the electrode 18, so that the electrode 18 and the abutting portion are
It is possible to prevent the occurrence of arc discharge in a place other than between 17. Moreover, the ceramic ring 10 is fitted to the outer periphery of the rotating body 7, and the coolant for flowing in the cooling water passages 5c and 5d provided along the rotating body 7 is welded for pipe making. Therefore, the rotating body 7 is cooled by the cooling water 14, and the ceramic ring body 10 is also indirectly cooled via the rotating body 7. Therefore, the arc of welding and the welding heat damage the metal tape 11 and the plastic. It is possible to prevent thermal deterioration of the coated filament 19. Furthermore, the arc does not damage the roll body 20.

〔The invention's effect〕

As described above, according to the welding roll of the metal pipe of the present invention, the metal tape is provided such that the long plastic-coated filaments are vertically attached to each other so that both end portions along the longitudinal direction of the metal tape are butted against each other. Is equipped with a roll body rotatably slidably contacting the surface of the metal tape, and after welding the abutting portions of the metal tapes to form the pipes, the metal tapes are sequentially sent out as the metal pipes in which the long plastic coated filaments are housed In the roll body, the outer peripheral surface region that is in sliding contact with the metal tape is composed of a ceramic ring body that is an insulator fitted to the outer periphery of the rotating body, and cooling for flowing cooling water along the rotating body. Since it has a water passage, it prevents the occurrence of an arc with the electrode, eliminates the need for readjustment of the operating state during pipe making and break-in operation, and does not replace the welding rolls for a long period of time. use Doo is possible, it can be produced efficiently stably high quality metal pipe with a high operating rate.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of one embodiment of the present invention,
FIG. 2 is a sectional view taken along line II-II of the same embodiment. 5c: Cooling water passage 5d: Cooling water passage 7: Rotating body 10: Ceramic ring body 11: Metal tape 17: Butt portion 19: Plastic coated filament 20: Roll body

Claims (1)

[Claims] 1. A metal tape (11) longitudinally covered with a long plastic-coated filament (19) is freely rotatable on the surface of the metal tape (11) so that both ends of the metal tape (11) are abutted to each other. The roll main body (20) slidably contacting with the metal tape (11) is welded to the butting portion (17) of the metal tape (11) to form the pipe, and then the metal tape (11) is attached to the long plastic-coated linear body (19). In a metal pipe welding roll that is sequentially sent out as a metal pipe housed inside, the roll body (20) has an outer peripheral surface region that is in sliding contact with the metal tape (11) and is insulated from the outer periphery of the rotating body (7). A metal which is composed of a ceramic ring body (10) as a body, and is provided with cooling water passages (5c) and (5d) for flowing cooling water (14) along the rotating body (7). Pipe welding rolls.