JPS6013551Y2 - Continuous pipe making machine for small diameter metal pipes - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a continuous pipe manufacturing machine for making small diameter metal pipes.

For example, a small stainless steel tube with an outer diameter of 4.0 m and a wall thickness of 0.2 m, an outer diameter of 5. -1 Wall thickness 0.6 chicken aluminum small diameter tube, outer diameter 2
．． When manufacturing small-diameter metal pipes such as stainless steel small-diameter pipes with a diameter of 0 m and a wall thickness of 0.15 m* by molding metal hoop materials and welding the joints of the hoop materials,
If the forming is not stable, the position of the joint of the metal hoop material will not be stable, making welding difficult.

In general, AC TIG welding, DC TIG welding, AC TIG welding, and high frequency welding are used to manufacture metal pipes with an outer diameter of 1 or FB or more, but the joints of metal hoop materials are The tubes are not required to be strictly stable.

Further, in this case, for example, a 4.0 mm diameter thorium-containing tungsten electrode is used for welding a stainless steel tube with an outer diameter of 12 mm.

On the other hand, the outer diameter is 4. - When welding small diameter stainless steel pipes, 4. If an Oxφ electrode is used, the diameters of the electrode and the small diameter tube will be the same, and the arc will not be stable.

Also, the penetration of the weld will be larger than necessary, so
This causes a decrease in the strength of the weld.

Therefore, when welding a small diameter metal tube of 4.0mφ, 1.6
A thorium tungsten electrode with a diameter of 2.4 mm or 2.4 mm is used, but by making the electrode thinner, it becomes necessary to stabilize the position of the seam of the hoop material.

In particular, when welding small-diameter aluminum metal pipes, it is important to stabilize the forming of the hoop material in order to stabilize the pipe production.

High-frequency TIG welding, laser welding, plasma arc welding, etc. are effective welding methods for aluminum, but in order to stabilize welding and perform excellent continuous welding with minimal penetration, stable forming is required. is the first.

Conventionally, all forming rolls for forming metal hoop materials were supported by bearings.

When the forming roll is supported by a bearing, the forming roll vibrates.

The vibration of the roll is several micrometers to several tens of micrometers when the roll rotates at high speed or when a load is applied to the roll.

When the roll vibrates, the metal hoop material becomes unstable, and the position of the seam of the metal hoop material becomes unstable.

An object of the present invention is to provide a continuous pipe-making machine for small-diameter metal pipes that can stably continuously manufacture small-diameter metal pipes by stabilizing the joint positions of metal hoop materials.

The continuous pipe manufacturing machine for small diameter metal pipes according to the present invention uses a gas bearing for the forming roll to suppress the vibration of the forming roll and stabilize the position of the seam of the metal hoop material. Gas is used to spray the end faces of the metal hoop material in the width direction during pipe making to blow off the metal powder on the end faces and cover the back side of the welded part in the subsequent process with an inert gas atmosphere.

Embodiments of the present invention will be described in detail below with reference to the drawings.

In the continuous pipe making machine for small diameter metal pipes of this embodiment, in order to continuously make pipes from the moving metal hoop material 1, a pair of shafts is provided correspondingly on both sides of the metal hoop material 1 in the width direction. 2 are erected, and an upper plate 3 is hermetically fixed to the upper end of each shaft 2, and a lower plate 4 is airtightly fixed to the outer periphery of the shaft 2 at a distance from the upper plate 3. .

A forming roll 5 is rotatably mounted on the outer periphery of the shaft 2 between the upper plate 3 and the lower plate 4.

An inert gas supply passage 6 is formed in the center of the shaft 2, and a plurality of pores 7 are formed radially through the shaft 2 at locations corresponding to the inner periphery of the forming roll 5. Inert gas is blown out into the gap 8 between the shaft 2 and the inner periphery of the forming roll 5.

The inert gas in the gap 8 is discharged to the outside through a gap 9 between the forming roll 5 and the upper plate 3 and a gap 10 between the forming roll 5 and the lower plate 4.

An umbrella part 3A is formed on the outer periphery of the upper plate 3, and an upper exhaust port 11 is formed downward between the umbrella part 3A and the forming roll 5 at the lower part of the upper plate 3. An inert gas is blown onto the end portion IA in the width direction.

In such a continuous pipe manufacturing machine for small diameter metal pipes, an inert gas such as nitrogen, argon, helium, etc. is supplied to the gas supply passage 6 of the shaft 2 at a rate of 4 to 6 kof/cn! When supplied, inert gas flows into the gaps 8, 9, and 10, and the forming roll 5 is floated by the inert gas and is gas-bearing, so that there is almost no frictional force on the forming roll 5. become.

In such a gas bearing, there is almost no vibration, and as mentioned above, there is also almost no friction, so the metal hoop material 1
There is almost no frictional force between the forming roll 5 and the metal hoop material 1, so the metal hoop material 1 hardly vibrates, and the metal hoop material 1
The joints can be welded stably.

Since the end IA of the metal hoop material 1 comes into contact with the other upper and lower forming rolls, metal powder is likely to adhere to it. Inert gas is spewed out from the exhaust port 11,
The metal powder may be blown away by spraying on the end IA of the metal hoop material 1 to prevent pinholes from occurring.

Furthermore, by spraying inert gas onto the end IA of the metal hoop material 1, oxidation of the end IA is prevented, and stable welding can be performed when welding hoop materials where oxidation is a problem, such as aluminum hoop materials. This makes it possible to more reliably prevent the occurrence of pinholes.

Furthermore, the inert gas blown to the end IA enters the tube of the formed metal hoop material 1, and covers the back side of the welded part in the subsequent process with an inert gas atmosphere to prevent oxidation of the back side of the welded part. To prevent.

Experimental Example 1 The continuous pipe manufacturing machine of the present invention was used to manufacture a stainless steel small diameter pipe with a diameter of 4.0 mm and a diameter of 0.4 mm.

An iron roll was used, and the surface was chrome plated.

Argon is about 5 kgf/cn as a gas! It was supplied by

The rolls are two sets of upper and lower rolls in front of the welding machine and two horizontal rolls.
I used a set.

A direct IG welding machine was used as a welding machine, and a thorium tungsten electrode with a diameter of 2.4 mm was used.

As a result, we were able to manufacture stable small-diameter stainless steel tubes with no pinholes.

Experimental Example 2 The continuous pipe making machine of the present invention was similarly used to manufacture a stainless steel small diameter pipe of 2.8 mφ x 0.18 mt.

A laser welder was used as the welder, and welding was performed with the spot diameter of the laser beam narrowed to 0.2 wsφ or less.

Since the joint of the stainless steel hoop material was stabilized by the continuous pipe forming machine of the present invention, stable welding without pinholes could be performed.

Experimental example 3 Aluminum small diameter tube 5.011ytφX O, 6rrr
The continuous pipe making machine of the present invention was similarly used to produce m t.

A high-frequency TIG welder was used as the welder, and zircoconium-containing tungsten 3.2 rrasφ was used as the electrode.

The aluminum hoop material passes through a degreasing device and a slitter device before forming, and 4 to 5 % of He is added to the gas bearing part to prevent oxidation.
kgf/al.

As a result, we were able to manufacture stable aluminum small-diameter tubes without pinholes.

As explained above, in the present invention, the forming roll is gas-bearing, so the vibration of the forming roll is almost eliminated, and the friction is also almost eliminated.Therefore, the vibration of the metal hoop material is eliminated, and the vibration between the metal hoop material and the forming roll is almost eliminated. Frictional force is almost eliminated, the position of the seam of metal hoop materials is stabilized, welding can be performed well, and small diameter metal pipes without pinholes can be stably manufactured.

In particular, in this invention, the gas bearing uses inert gas as the gas, and this is sprayed from the upper exhaust port opened at the bottom of the upper plate to the widthwise end of the metal hoop material. The metal powder can be blown away from the edge of the weld, eliminating welding obstacles and more reliably preventing the occurrence of pinholes.

In addition, oxidation of the ends of the metal hoop material can be prevented.

Furthermore, the inert gas blown to the end of the metal hoop material enters the pipe of the metal hoop material during pipe making, and covers the back side of the welded part in the subsequent process with an inert gas atmosphere, preventing oxidation on the back side of the weld. It can be prevented.

[Brief explanation of drawings]

The drawing is a cross-sectional view showing an embodiment of a continuous pipe manufacturing machine according to the present invention. 1...Metal hoop material, 2...Shaft, 3.
...Top plate, 4...Bottom board, 5...
Forming roll, 6...Inert gas supply passage, 7.
...Pore, 8,9,10...Gap,
11...Top exhaust port.

Claims (1)

[Scope of utility model registration request] In a continuous tube making machine for making small diameter metal pipes by forming a metal hoop material between forming rolls arranged in pairs, the forming rolls are rotatably fitted around the outer periphery of a shaft. an upper plate is provided on the shaft so as to face the upper surface of the forming roll with a gap therebetween; a lower plate is provided on the shaft so as to face the lower surface of the forming roll with a gap therebetween; A gap is formed between the inner periphery of the forming roll and the outer periphery of the shaft, and an inert gas supply passage is formed in the shaft along its longitudinal direction, and the inert gas supply passage and each gap are connected to each other. A pore is formed in the shaft in the radial direction so as to communicate with each other, and in the lower part of the upper plate, the inert gas supplied from the inert gas supply passage is connected in the width direction of the metal hoop material during pipe making. A continuous pipe manufacturing machine for small diameter metal pipes, characterized in that an upper exhaust port for blowing air onto the end face of the pipe is opened.