JP2000202520A - Manufacture of pipe coated with aluminum - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make thermal conductivity higher and heat capacity smaller and to improve the mechanical characteristics at the time of high temperature by coating the outer side of a metallic pipe with a pipe of aluminum or aluminum alloy by a shrinkage fit. SOLUTION: The outer side of the metallic pipe essentially consisting of copper, iron or nickel is coated with the pipe made of the aluminum or aluminum alloy by the shrinkage fit. At this time, a low melting metal or alloy of a melting point below the melting point of the aluminum between the core material pipe and the aluminum is applied to either of the outer surface on the core material side or the inner surface on the aluminum side. Metals, such as zinc, indium, cadmium and tin, and alloys, such as aluminum-zinc, aluminum- germanium, aluminum-silicon and aluminumcadmium, are enumerated as the low melting metal. Electroplating, hot dip coating, wire brushing of molten metal, etc., are used as the coating application method. The coating application thickness is specified to about 0.001 to 1 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical heating element.

[0002]

2. Description of the Related Art Cylindrical heating elements used for toner printing rollers of copying machines and hot rolling rollers of plastics are:
A heater wire is disposed in the center of the cylinder, and heats the cylinder on the outer periphery thereof, and functions as a heating element. As for the material of the cylinder, a thick roller made of an aluminum alloy is mainly used for a copying machine, and an iron roller is used for a plastic.

[0003]

The problems to be solved by the present invention are the following two points.

[0004] Aluminum or aluminum alloy (hereinafter aluminum) has high thermal conductivity, but poor strength and rigidity at high temperatures. Therefore, it is thickened to assist the insufficient mechanical properties. Aluminum has a large heat capacity, so that thickening would waste time and power to heat the roller to a predetermined temperature. Iron is
High strength and rigidity at high temperature, but low thermal conductivity,
There is a disadvantage that the heat uniformity of the roller surface is poor.

[0005] As described above, eliminating the disadvantages of aluminum or iron rollers immediately results in high thermal conductivity.
Another object of the present invention is to provide a method for producing a roller having a small heat capacity and good mechanical properties at high temperatures.

[0006]

In order to solve the above problems, first, a thin iron pipe is prepared, and this is cast in a molten aluminum, and an aluminum part having a considerable thickness is required. It turned out to be. When this is used as it is as a roller, it becomes a roller having a considerably large heat capacity. Therefore, this thick portion is turned to form a thin roller, but this method is costly.

Therefore, from the beginning, in order to form a thin roller, a shrink-fitting method is adopted. According to this method, a core material such as iron (hereinafter referred to as a core material) is excellent in strength and rigidity at a high temperature, and aluminum has a good thermal conductivity, and a thinner material has a smaller heat capacity, which is preferable. Furthermore, in the shrink fitting, since the core material and the aluminum can be made of thin materials from the beginning, the cost is reduced.

As the core material, copper, iron, nickel or the like having a smaller coefficient of thermal expansion than aluminum can be used, and stainless steel, inconel, bronze or the like can be used. Ideally, there is no gap between the core material and the aluminum, and shrink-fitting is performed. However, there is a great possibility that a slight gap is actually formed. Therefore, as described in claim 2, a low melting point metal having a melting point lower than that of aluminum or an alloy thereof is applied to one or both of the outer surface on the core material side and the inner surface on the aluminum side. An alloy or an element described in claim 3 is used as a typical low melting point metal. or,
As the coating method, a method such as electroplating, hot-dip plating, and wire brushing of the hot metal can be used. The coating thickness at this time is 0,0
Performing in the range of about 01 mm to 1 mm, and as set forth in claim 5, if the shrink-fitting temperature is equal to or higher than the melting point of the alloy,
The excess coating thickness is excluded as a liquid during shrink fitting. The aluminum-coated pipe thus obtained has no gap between the core material and the aluminum, and the thermal conductivity is further increased.

The aluminum-coated pipe obtained as described above may be used as it is, but when extremely high precision is required, the pipe is further provided with a thickness of 400-55.
While maintaining the temperature at 0 ° C., diffusion bonding is performed to strengthen the bonding between the core material and the aluminum, and it is also possible to remove distortion during the manufacturing process. Further, instead of the diffusion bonding in claim 7, a method of correcting the bonding distortion or promoting the bonding by using a heated mold may be used.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a sectional view of a pipe coated with aluminum according to the present invention. FIG. 2 is a sectional view of the pressure joining according to claim 7 of the present invention.

EXAMPLE 1 A stainless steel (SUS430) pipe having an outer diameter of 40 mm, a thickness of 2 mm, and a length of 300 mm was immersed in a molten alloy of 50% Al and 50% Zn, and the outer peripheral surface of the pipe was adjusted to about 0.05.
mm. On the other hand, the inner diameter is 40 mm and the thickness is 3 mm
After heating a 300 mm long aluminum (A5052) pipe to 450 ° C., the stainless steel pipe was inserted into the pipe to complete the shrink fit.

Example 2 An iron pipe having an outer diameter of 25 mm, a thickness of 1 mm, and a length of 500 mm was plated with tin having a thickness of 15 μm on the entire surface. On the other hand, after heating an aluminum (A1015) pipe having an inner diameter of 25 mm, a thickness of 5 mm, and a length of 500 mm to 300 ° C., the iron pipe was inserted into the pipe.

The aluminum-coated iron pipe obtained as described above was kept at 400 ° C. for 20 hours to perform diffusion bonding to complete shrink fitting.

Example 3 Inconel 6 having an outer diameter of 10 mm, a thickness of 1 mm, and a length of 600 mm
Aluminum-cadmium solder was applied to the outer diameter side of the 00 pipe at 500 ° C. with a wire brush, and the temperature was returned to room temperature. On the other hand, aluminum (A60
61) Pipe (size inner diameter 10 mm, wall thickness 1 mm, length 6)
(00 mm) was heated to 500 ° C. while inserting the Inconel pipe.

The aluminum-coated Inconel pipe obtained as described above is pressure-bonded at 400 ° C. with a pressure of 200 kg / cm ² using a pressure-bonding mold shown in FIG. Was completed.

The roller obtained in Example 1 is used as a roller for hot rolling of plastics, the one obtained in Example 2 is used as a roller for a copying machine, and the roller obtained in Example 3 is used as a pipe heater. Each of the sections was polished and confirmed by a color check method. As a result, no gap was present between the aluminum and the core material. In each case, the maximum temperature of 35 which is usually used
Since there was no deformation of the pipe at 0 ° C., it could be used as a heating roller without any shortage.

[0017]

The effects of the present invention and the conventional roller are shown in Tables 1 and 2. Tables 1 and 2 show that the roller of the present invention has excellent heat conduction and small heat capacity in any case.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a pipe coated with aluminum according to the present invention.

FIG. 2 is a cross-sectional view of a method of performing pressure bonding using a mold that is a part of the present invention.

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] April 14, 1999 (1999.4.1
4)

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Explanation of sign

[Correction method] Added

[Correction contents]

[Explanation of Signs] 1, core material 2, low melting point metal 3, aluminum pipe 4, mold

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B32B 1/08 B32B 1/08 A F-term (Reference) 4E067 AA02 AA05 AA07 AA09 AB01 AB03 AD09 AD10 BA00 BB02 DC06 EB00 EC06 4F100 AB01C AB02A AB04 AB10B AB10C AB11C AB16A AB17A AB18C AB21C AB23C AB31B AB31C BA02 BA03 BA07 BA10A BA10B DA11 DD31 EH661 EH711 EH901 EJ202 EJ412 EJ421 EJ472 GB48 JA04C JJ01 JJ10

Claims (7)

[Claims] 1. A method of manufacturing an aluminum-coated pipe in which the outside of a metal pipe mainly containing copper, iron or nickel is shrink-fitted with a pipe made of aluminum or an aluminum alloy. 2. A method according to claim 1, wherein a low melting point metal is previously applied to the outside of a metal pipe containing copper, iron or nickel as a main component, or to the inside of an aluminum or aluminum alloy pipe. How to fit. 3. The low-melting alloy according to the preceding claim, which includes metals such as zinc, indium, cadmium, tin and lead, aluminum-zinc, aluminum-germanium, aluminum-
A method using an alloy such as silicon or aluminum-cadmium. 4. The method of applying a low-melting-point alloy according to the preceding item is an electroplating, an electroless plating, a vapor deposition, a hot-dip plating, a wire brush, or a coating method using an iron. 5. The method according to claim 2, wherein the aluminum or aluminum alloy is heated to 150 to 550 ° C.
How to do shrink fit. 6. After shrink-fitting according to the method of the preceding paragraph, further 40.
A method of maintaining the temperature at 0 to 550 ° C. and performing diffusion bonding. 7. The method according to claim 1, wherein instead of performing diffusion bonding,
A method of pressure bonding using a mold.