JPH07224394A - Method for heat-treating metallic tube - Google Patents

Abstract

PURPOSE:To provide the method for heat-treating a metallic tube without need for an intricate operation, capable of being easily applied to an existing annealing furnace and capable of effectively removing a lubricating oil component from the inside of a coiled tube. CONSTITUTION:A cylindrical gas holder 15 is provided in the central space of a coiled tube 1, one end of the tube is connected to the holder to fill the inside of the tube with the gas, the tube is passed through a heater, hence the oil remaining in the tube is vaporized, and the heat decomposition component of the lubricating oil vaporized in the tube is discharged outside the tube by the increased gas pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment method for metal pipes, and more particularly to a thermal decomposition component of lubricating oil vaporized by heat treatment while flowing a gas inside a coil pipe (hereinafter referred to as a lubricating oil component) outside the pipe. The present invention relates to a heat treatment method for a metal pipe to be discharged to.

[0002]

2. Description of the Related Art In some cases, the lubricating oil used during processing adheres to the inside of a coil tube. This lubricating oil is thermally decomposed by heat (for example, 450 ° C.) during annealing of the coil tube to generate a thermally decomposed product. Although a part of the thermal decomposition product is spontaneously discharged by vaporization, it may remain in the pipe even after the heat treatment, which is not preferable for use depending on the application and needs to be completely discharged.

FIG. 4 shows a conventional metal tube heat treatment apparatus,
A gas injection tube 4 is connected to the coil tube 1 mounted on the tray 2 at one end 3 thereof by brazing or the like, and the injection tube 4 is connected to a header 6 via an opening / closing valve 5. It is connected. This header 6 branches the gas supplied from a gas cylinder 8 described later into each system and supplies the gas to the header 6 via a pressure reducing valve 7 by a gas cylinder 8 filled with an inert gas or an atmospheric gas. Supplied.

FIG. 5 is an explanatory view of a roller hearth type bright annealing furnace having no door at the entrance and exit of the coil tube 1. The coil tube 1 mounted on the tray 2 and connected to the injection tube 4 is a roller conveyor 9 Are conveyed in the direction A shown in the figure by the front chamber 10, the heating furnace 11, the cooling chamber 12, and the rear chamber 1.
Annealing is performed by passing through in the order of 3.

The operation of the above metal tube heat treatment apparatus will be described below. The coil tube 1 mounted on the tray 2 is the terminal 3
It is moved by the roller conveyor 9 together with the injection tube 4 brazed to and heated in the heating furnace 11.

By this heating, the lubricating oil remaining inside the coil tube 1 is vaporized and filled inside the coil tube 1 as a lubricating oil component. After that, when the opening / closing valve 5 is opened, the gas is sent into the coil tube 1 through the pressure reducing valve 7 and the header 6, and the lubricating oil component filled in the tube is pushed out and discharged. The open / close valve 5 is closed after the discharge of the lubricating oil component from the coil tube 1 is completed.

On the other hand, the injecting tube 4 is cut and removed after the coiled tube 1 is discharged from the rear chamber 13.

[0008]

However, according to the conventional metal tube heat treatment apparatus, the heat treatment is performed by passing through the annealing furnace with the gas injection tube connected to the coil tube.
It takes time to connect and disconnect the injection tube. Further, in the case of a roller hearth type bright annealing furnace having a door in the annealing furnace, there is a problem that the furnace must be modified in order to pass through the injection tube. Therefore, an object of the present invention is to provide a metal tube heat treatment method which can be easily applied to an existing annealing furnace without requiring complicated work and can effectively remove a lubricating oil component from the inside of a coil tube. .

[0009]

The present invention can be easily applied to existing annealing furnaces without requiring complicated work, and effectively removes the lubricating oil component from the inside of the coil tube. A cylindrical gas container having a gas injection hole on the upper surface is provided in the partial space, and the gas container is connected to one end of the coil tube,
The gas container is filled with gas from the other end of the coil tube through the coil tube, and the coil tube filled with the gas and the gas container are passed through a heating device for heat treatment to remove oil remaining in the coil tube. By vaporizing and increasing the volume of the gas to increase the gas pressure and discharging the gas whose volume has been increased by the heat treatment from the other end, the pyrolyzed components of the lubricating oil vaporized in the coil pipe are discharged to the outside of the coil pipe. A method for heat treating a metal tube is provided.

[0010]

According to the present invention, when the coil tube and the gas container are filled with gas and passed through the heating device, the lubricating oil remaining in the coil tube is vaporized and the gas filled in the gas container is The internal pressures of the coil tube and the gas container rise due to the increase. Due to this volume increase, the gas discharges the lubricating oil component vaporized based on the increased internal pressure of the coil tube and the gas container to the outside of the coil tube from the other end.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The metal tube heat treatment method of the present invention will be described in detail below with reference to the drawings. The parts having the same configurations and functions as those of the conventional art are denoted by the same reference numerals, and thus the duplicate description will be omitted.

1 (A) and 1 (B) are sectional views of a gas container and a coil tube in the metal tube heat treatment method of the present invention, in which the central space of the coil tube 1 mounted on the tray 2 is ( As shown in B), one end of the coil tube 1 is connected to the upper surface of the connection fitting 14
Connection hole 15A and gas vent hole 15 connected by A
A gas container 15 having B is contained. Coiled tube 1
The other end of the gas injection hose 16 is connected through a connection fitting 14B.
It is connected to the.

In order to remove the lubricating oil component inside the coil tube 1, first, the coil tube 1 is mounted on the tray 2, and the gas container 15 is housed in the central space thereof to connect the connection hole 15A and the coil tube 1. Is connected to one end of the connector by a connecting fitting 14A. Next, the other end of the coil tube 1 and the gas injecting hose 16 are connected by the connecting fitting 14B. The gas injection hose 16 is connected to gas supply means (not shown).

Next, the gas container 1 is supplied from a gas supply means (not shown) through the gas injection hose 16 and the coil tube 1.
Supply gas into

When the inside of the gas container 15 is sufficiently filled with gas, the gas is blown out from the gas vent hole 15B. After confirming this gas ejection, the gas vent hole 15B is closed, the gas supply is stopped, and the gas injection hose 16 is removed from the other end of the coil tube 1.

Next, the coil tube 1 and the gas container 15 mounted on the tray 2 are heated and annealed by passing through the roller hearth type bright annealing furnace shown in FIG. This roller hearth type bright annealing furnace is provided between the front chamber 10 and the heating furnace 11 which are located in the conveyance direction of the roller conveyor 9, and the heating furnace 11
And doors 17A, 17B, 17C and 17D which are provided between the cooling chamber 12 and between the cooling chamber 12 and the rear chamber 13 and open and close up and down. When the tray 2 is transported to the spaces of the front chamber 10, the heating furnace 11, the cooling chamber 12, and the rear chamber 13, these blocks the front and rear of the tray 2.

When the coil tube 1 and the gas container 15 mounted on the tray 2 are conveyed to the heating furnace 11 by the roller conveyor 9, the front and rear doors 17B and 17C are closed.
The coil tube 1 and the gas container 15 are heated by being conveyed in the direction A through the heating furnace 11 closed by the doors 17B and 17C, and the entire temperature rises, and remains inside the coil tube 1. Lubricating oil vaporizes.

Further, the gas filled in the coil tube 1 and the gas container 15 is thermally expanded and its volume is increased.
The internal pressure of 5 rises. As a result, the lubricating oil component vaporized inside the coil tube 1 is discharged from the other end of the coil tube 1 by the pressure of the gas whose volume has increased.

When the lubricating oil remaining in the coil tube 1 is vaporized by heating and is discharged by utilizing the pressure of the thermally expanded gas, the pressure of the gas is sufficient to discharge the vaporized lubricating oil component from the inside of the tube. It is necessary to obtain

As a method of increasing the gas pressure, for example, the cylindrical shape of the gas container 15 is enlarged in the longitudinal direction to increase the internal volume, or a pressure valve that is opened at a predetermined pressure is provided, and the inside of the coil tube 1 is provided. It is conceivable to take measures such as discharging the lubricating oil component vaporized in step 2 to the outside of the pipe with a gas of a predetermined pressure.

3A and 3B show a modification of the present invention,
A pressure valve 21 having an aluminum foil 19 fixed by a fixing member 20 is provided at the other end of the coil tube 1.

The pressure valve 21 is provided at the other end of the coil tube 1 when the gas filled in the coil tube 1 and the gas container 15 is thermally expanded by heating in the heating furnace 11 to reach a predetermined gas pressure. The aluminum foil 19 thus ruptured breaks and the lubricating oil component and gas are discharged to the outside of the pipe. That is, when the aluminum foil 19 provided on the other end of the coiled tube 1 is broken by the pressure of the gas, the gas discharged to the outside of the tube has a flow velocity based on the increased pressure. Promptly discharged outside the pipe.

Therefore, by adjusting the thickness of the aluminum foil 19 provided on the other end of the coil tube 1, it is possible to arbitrarily set the gas pressure sufficient to discharge the lubricating oil component to the outside of the tube.

Further, instead of the aluminum foil 19, a melting valve that melts at a predetermined temperature is provided, and the temperature reaches a temperature at which a gas pressure sufficient to discharge the lubricating oil component vaporized in the coil tube 1 to the outside of the tube is obtained. The gas may be discharged to the outside of the tube by melting at that time.

By thus connecting the coil tube 1 mounted on the tray to the gas container and transporting the gas in the heating furnace, the lubricating oil component vaporized by heating in the existing heating furnace is expanded in volume of the gas. It can be effectively discharged by the discharge action based on. In addition, the removal of the gas container after the removal of the lubricating oil component can be easily performed by removing the connection fitting.

[0026]

As described above, according to the metal tube heat treatment method of the present invention, a cylindrical gas container having a gas injection hole on the upper surface is provided in the central space of the coil tube, and the gas is accommodated at one end of the coil tube. Inside the coil tube by connecting the bodies, filling the gas container from the other end of the coil tube with the gas through the coil tube, and passing the gas into the coil tube and the heating device that heats the gas container. The oil remaining in the oil is vaporized and the volume of the gas is increased to increase the gas pressure,
By discharging the gas whose volume has been increased by the heat treatment from the other end, the pyrolyzed components of the lubricating oil vaporized in the coil pipe are discharged to the outside of the coil pipe, so that existing work can be performed without complicated work. It can be easily applied to an annealing furnace and can effectively remove the lubricating oil component from the inside of the coil tube.

[Brief description of drawings]

1A is a cross-sectional view of a coil tube 1 and a gas container 15 in a metal tube heat treatment method of the present invention, and FIG. 1B is a perspective view of the gas container 15.

FIG. 2 is an explanatory view of a roller hearth type bright annealing furnace in the metal tube heat treatment method of the present invention.

FIG. 3 shows a modified example of the metal tube heat treatment method of the present invention.

FIG. 4 is an explanatory view showing a conventional metal tube heat treatment apparatus.

FIG. 5 is an explanatory view showing a conventional metal tube heat treatment apparatus.

[Explanation of symbols]

1 Coil pipe 2 Tray 3 Terminal 4 Injection tube 5 Opening / closing valve 6 Header 7 Pressure reducing valve 8 Gas cylinder 9 Roller conveyor 10 Anterior chamber 11 Heating furnace 12 Cooling chamber 13 Rear chamber 14A, 14B Connection fitting 15 Gas container 15A Connection hole 15B gas Vent hole 16 Gas injection hose 17A, 17B, 17C, 17D Door 19 Aluminum foil 20 Fixing member 21 Pressure valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Norio Suzuki 3550 Kidayomachi, Tsuchiura City, Ibaraki Prefecture Hitachi Cable Ltd. Tsuchiura Plant

Claims (3)

[Claims] 1. A cylindrical gas container having a gas injection hole on its upper surface is provided in a central space of a coiled metal tube (hereinafter referred to as a coil tube), and the gas container is provided at one end of the coil tube. The body is connected, and an inert gas or an atmospheric gas (hereinafter, simply referred to as a gas) is supplied from the other end of the coil tube to the gas container through the coil tube to fill the gas container with the inert gas. By passing the coil tube and the gas container through a heating device for heat treatment, the thermally decomposed component of the lubricating oil vaporized in the coil tube is discharged to the outside of the coil tube. Heat treatment method. 2. The other end of the coil tube has a pressure valve that is opened when the inert gas contained in the coil tube and the gas container reaches a predetermined pressure based on the heat treatment. The method for heat treating a metal tube according to claim 1, comprising. 3. The metal tube heat treatment method according to claim 1, wherein the other end of the coil tube has a melting valve that melts at a predetermined temperature in the heat treatment.