JPH0285349A - Manufacture of metallic tube for far infrared radiation - Google Patents

Abstract

PURPOSE:To efficiently manufacture the title tube without impairing environment by continuously forming fine ruggedness on the whole outer peripheral surface or the whole inner peripheral surface of a metallic pipe and thereafter forming an oxide film onto the rugged part. CONSTITUTION:The whole outer peripheral surface of a metallic tube P1 conveyed in the direction of the arrow is irradiated with an electron beam or a laser via a slit ring 10 having many parallel slits 11a successively in the circumferential direction or in the longitudinal direction by an electron beam or laser generating apparatus 11. In this way, fine ruggedness is continuously formed onto the whole outer peripheral surface of the above metallic tube P1. The pitch of the ruggedness is suitably regulated to about 2 to 15mu and the height to about 5 to 30mu. After that, the above metallic tube P1 is subjected to high temp. heat treatment in an oxidizing atmosphere to form an oxide film onto the above rugged part. In this way, the metallic tube for far infrared radiation can efficiently be obtd. without the generation of noise, dust or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a method of manufacturing a metal tube for far-infrared radiation.

In recent years, far infrared rays have been widely used in various industrial fields, such as heating equipment, as well as drying and baking of paint, adhesion of plywood, and heating processing of various foodstuffs.

Generally, ceramics are known as materials that efficiently emit far-infrared rays when heated to high temperatures.

Conventionally, the outer peripheral surface of a metal tube is blasted, a radiation layer of a mixture of ceramic powder and an inorganic paint is coated on the blast-treated outer peripheral surface of the metal tube, and the outer circumference of the applied radiation layer is A method for manufacturing a far-infrared radiating element whose surface is blast-treated is disclosed in JP-A-55-2754.

"Issues to be Solved by the Invention aJ" By the way, in the technology disclosed in the above-mentioned published patent application, there are two steps: a first step of treating the outer peripheral surface of the metal tube with plastic, and a second step of treating the outer peripheral surface of the metal tube after this first step. Since the far-infrared radiating element is manufactured by a second step of applying a radiation layer to the surface and a third step of performing a blast treatment on the outer circumferential surface of the radiation layer after the second step, productivity is extremely low. In particular, blasting has the problem of significantly harming the environment due to the generation of noise and dust.

The present invention has developed a method for manufacturing a metal tube for far-infrared radiation in order to solve the above-mentioned conventional problems.

"Means for Solving the Problems" The first gist of the present invention is to provide a slit ring having a large number of parallel slits sequentially in the circumferential direction and the longitudinal direction on the entire outer peripheral surface of the metal tube being transported. After irradiating an electron beam or laser through the metal tube to continuously form fine irregularities on the entire outer peripheral surface of the metal tube, an oxide film is generated on the irregularities in a high temperature oxidizing atmosphere, and far infrared rays are emitted. The purpose of this company is to manufacture metal pipes for industrial use.

The second gist of the present invention is that an electron beam or laser is applied to the entire inner peripheral surface of the metal tube being transported through a slit ring having a large number of parallel slits sequentially in the circumferential direction and the longitudinal direction. irradiation to continuously form fine irregularities on the entire inner circumferential surface of the metal tube, and then generate an oxide film on the irregularities in a high temperature oxidizing atmosphere to produce a metal tube for far infrared radiation. There is a particular thing.

"Operation" According to the first aspect of the present invention, an electron beam or a laser beam is applied to the entire outer circumferential surface of the metal tube being transported through a slit ring having a large number of parallel slits sequentially in the circumferential direction and the longitudinal direction. By irradiating the metal tube, fine irregularities can be continuously formed on the entire outer circumferential surface of the metal tube, and an oxide film can be formed on the irregularities under a high temperature oxidizing atmosphere, so that the outer circumferential surface A metal tube that can emit far-infrared rays can be manufactured.

Further, as in the second aspect of the present invention, the entire inner peripheral surface of the metal tube being transported is irradiated with an electron beam or a laser through a slit ring having a large number of parallel slits sequentially in the circumferential direction and the longitudinal direction. By doing so, fine irregularities can be continuously formed on the entire inner circumferential surface of the metal tube, and an oxide film can be formed on the uneven parts under a high temperature oxidizing atmosphere, so that the inner circumferential surface A metal tube that can emit far-infrared rays can be manufactured.

"Example" Next, a first example of the method for manufacturing a metal tube for far-infrared radiation according to the present invention will be described below with reference to FIGS. 1 to 4.

Figure 1 shows the roll forming process 1 of the steel strip S that has been fed out from the uncoiler and site-rimmed, and the fin pass forming process 2 for finish forming of the raw pipe P during the production line for electric resistance welded steel pipes using the roll forming method. , welding process 3 of the pre-joint edge part of the finish-formed base pipe P, cutting process 4 of the inner and outer surface beads of the ERW steel pipe P+ whose pre-joint edge part is welded, boss annealing process 5, and cooling process 6.
This is a schematic diagram showing a sizing process 7, a cutting process 8, and a straightening process 9. As shown in FIGS. A slit ring 10 having a large number of parallel slits 10a sequentially in the circumferential direction and the longitudinal direction is placed on the outer periphery of the electric resistance welded steel pipe p+.
The electric resistance welded steel pipe P1 is fitted with a required gap, and the entire outer peripheral surface of the electric resistance welded steel pipe P1 is irradiated with an electron beam or a laser from the electron beam or laser generator 11 through the slit ring 10. On the entire outer peripheral surface of the PI,
Continuously form unevenness a as shown in Fig. 4,
Thereafter, the oxidizing solution II! is placed in a heat treatment furnace in an oxidizing atmosphere and subjected to high temperature heat treatment, thereby injecting the oxidizing liquid II! This is to produce an electric resistance welded steel pipe that can generate far-infrared rays and emit far-infrared rays from its outer peripheral surface.

The pitch of the fine unevenness a is 2 to 15 μm and the height is 5 to 30 μm, and the shape of the fine unevenness a can be changed by changing the irradiation angle of the electron beam or laser, or by changing the slit 10a of the slit ring 10. By changing the shape of the surface, various shapes of unevenness can be formed.

Further, means for fitting and installing the slit ring 10 on the outer periphery of the electric resistance welded steel pipe PL with a required gap, and means for installing the electron beam or laser generator 11 on the outer periphery of the slit ring 10 with a required gap, etc. , any supporting means may be employed.

Next, a second embodiment of the method for manufacturing a metal tube for far-infrared radiation according to the present invention will be described below with reference to FIGS. 5 and 6.

The second embodiment of the method of the present invention shown in FIGS.
On the exit side of the straightening process 9 shown in the figure, a large number of parallel slits 7 10a are formed in the circumferential direction on the inner periphery of the straightened 1i sewn steel pipe P1.
A slit ring 10 that grows sequentially in the longitudinal direction is fitted to the electric resistance welded steel pipe P1 with a required gap, and an electron beam or laser generator 1! is emitted through the slit ring lO.
The entire inner peripheral surface of the ERW steel pipe P1 was irradiated with an electron beam or a laser from the ERW steel pipe P1, and fine irregularities a similar to those shown in FIG. 4 were continuously formed on the entire inner peripheral surface of the ERW steel pipe P1. Thereafter, an oxide film is formed on the uneven portions in a high-temperature oxidizing atmosphere to produce an electric resistance welded steel pipe capable of emitting far-infrared rays from its inner peripheral surface.

In addition, means for fitting and installing the slit ring IO on the inner periphery of the electric resistance welded steel pipe p+ with a required gap, and means for installing an electron beam or laser generator zit on the inner periphery of the slit ring 10 with a required gap. etc.,
Any supporting means may be used.

"Effects of the Invention" As described above, according to the present invention, fine irregularities that can efficiently radiate far-infrared rays are formed on the outer circumferential surface or inner circumferential surface of the metal tube while the metal tube is being transported. After being formed by irradiating the outer circumferential surface or inner circumferential surface of the metal tube with an electron beam or laser, an oxide film can be generated on the uneven portions in a high temperature oxidizing atmosphere.
There is no risk of harming the environment by generating noise or dust,
A metal tube for far-infrared radiation can be manufactured efficiently.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing a first embodiment of the method for manufacturing a metal tube for far-infrared radiation according to the present invention, FIG. 2 is a partially cutaway enlarged schematic side view of the main part, and FIG. Sectional view of Fig. 2, No. 4
The figure is an enlarged explanatory diagram of a fine uneven shape with an oxide film, No. 5I! 1 is a partially cutaway enlarged schematic side view of a main part in a second embodiment of the method of the present invention, and FIG. 6 is a sectional view of FIG. 5. S...Steel strip, 1...Roll forming process, P.
...Main pipe, 2...Fin pass forming process, 3...Welding process, 4...Cutting process for inner and outer beads, 5...Boss annealing process, 6...Cooling process, 7... Sizing process, 8... Cutting process, 9... Straightening process, 10.
... Slit ring, 11... Electron beam or laser generator, a... Fine irregularities, b... Oxide film Figures 4 and 5, Figure 6

Claims (2)

[Claims] (1) An electron beam or laser is irradiated onto the entire outer peripheral surface of the metal tube being transported through a slit ring that has many parallel slits sequentially in the circumferential and longitudinal directions. A method for manufacturing a metal tube for far-infrared radiation, characterized by continuously forming fine irregularities and then generating an oxide film on the irregularities under a high-temperature oxidizing atmosphere. (2) The entire inner circumferential surface of the metal tube being transported is irradiated with an electron beam or laser through a slit ring having a large number of parallel slits in the circumferential direction and longitudinal direction, and the entire inner circumferential surface of the metal tube is A method for manufacturing a metal tube for far-infrared radiation, characterized by continuously forming fine irregularities on a surface, and then generating an oxide film on the irregularities in a high-temperature oxidizing atmosphere.