JP2002361341A - Method for producing metallic pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a metallic pipe by which a straight shape metallic pipe can be formed in an opposite crown form at high accuracy and inexpensively. SOLUTION: In the combination of a columned member 1 and the metallic pipe 2 having a linear expansion coefficient lower than that of the former, the straight shape metallic pipe 2 is inserted into the opposite crown shape columned member 1 and is formed in the opposite crown form by heating at least the columned member 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a metal pipe.

[0002]

2. Description of the Related Art Conventionally, copiers and printers of monochrome machines,
As a fixing method used in an image forming apparatus such as a facsimile, a heat roller fixing method is used in a wide range of low-speed machines, medium-speed machines and even high-speed machines.

However, in the conventional heat roller fixing method, it is necessary to heat a fixing roller having a large heat capacity in advance in order to supply sufficient heat to the toner as a recording material. In addition, there is a problem that the time until the first print is long.

In order to solve the above problem, various fixing systems have been devised so far. As a typical system, a fixing roller having a large heat capacity is changed to a thin polyimide resin film having a low heat capacity called a fixing film, and the temperature is reduced. A fixing method has been devised in which the thermal conductivity is greatly improved by directly contacting a controlled ceramic heater with the fixing film under pressure, and energy saving and a quick start property that requires almost no warm-up time are devised.

[0005]

However, in a fixing device using a conventional fixing film, although excellent energy saving and quick start-up with reduced warming-up time can be achieved, with the recent increase in fixing speed, There has been a problem that a warm-up time of zero due to instantaneous heating cannot be obtained, heat supply to the toner as a recording material cannot keep up, and a fixing defect occurs.

As a measure for solving the above problem, for example, Japanese Patent Application Laid-Open No. Hei 10-319753 discloses energy saving and warm-up time by using a metal film of a good heat conductor instead of a heat-resistant resin film as a base material of a fixing film. However, this method is based on the premise that a thin nickel metal film formed by nickel electroforming with a thickness of about 50 μm is used, and this method has problems such as durability and cost of the fixing film itself. There is.

The present invention has been made in view of the above problems, and an object thereof is to provide a method of manufacturing a metal pipe capable of forming a straight metal pipe into an inverted crown shape with high accuracy and at low cost. Is to do.

[0008]

In order to achieve the above object, the present invention relates to a combination of materials having a linear expansion coefficient of a metal pipe smaller than a linear expansion coefficient of a cylindrical member. The metal pipe is inserted into a cylindrical member, and the metal pipe is formed into an inverted crown shape by heating at least the cylindrical member.

[0009]

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

<First Embodiment> FIGS. 1 to 10 show a first embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a cylindrical member as a mandrel into which a metal pipe is inserted. In the present embodiment, a solid rod member is used. Reference numeral 2 denotes a tubular or hollow metal pipe having an inner diameter through which the cylindrical member 1 is inserted.

In the present embodiment, the cylindrical member 1
Used is polyetheretherketone (PEEK), and the metal pipe 2 is SUS304. The linear expansion coefficient of PEEK is 4.5 × 10 ^-5 (/
℃), the linear expansion coefficient of SUS304 is 1.7 × 10 ^-5 (/
° C).

Next, a specific embodiment will be described.

The size of the cylindrical member 1 is selected according to the inner diameter of the metal pipe 2 to be manufactured. First, as the metal pipe 2, a SUS304 pipe, here having an inner diameter of 25.00 m, is used.
A piece cut to dimensions of m, thickness 0.1 mm and length 227.0 mm is prepared. As shown in FIG. 2, the columnar member 1 is an inverted crown in shape, the diameter 1a at both ends is 24.95 mm, and the diameter 1b at the center is 24.90.
mm.

The outer diameter of the cylindrical member 1 and the metal pipe 2 are set to be smaller than the outer diameter of the metal pipe 2 at a temperature of 150 ° C. by heating in a heating step described later. It is designed in advance so as to exceed 05 mm.

Here, as shown in FIG. 1, the cylindrical member 1 is inserted into the hollow portion of the metal pipe 2. Then, the cylindrical member 1 and the metal pipe 2 are inserted into the heating furnace 3 shown in FIG. The heating conditions in the heating furnace 3 are a heating temperature of 150 ± 5 ° C. and a heating time of 30 ± 1 minute. The heating conditions are determined in consideration of the temperature and pressure reaching the plastic deformation region of the metal pipe 2.

Next, the heating step will be described in detail below.

In the heating step in the heating furnace 3, the cylindrical member 1 and the metal pipe 2 change as shown in FIGS.

First, a metal pipe 2 placed in a heating furnace 3
Is at room temperature between the mandrel and the columnar member 1 and the center is 0.1 mm.
It has a gap of 1 mm and both ends 0.05 mm (FIG. 5). From this state, the cylindrical member 1 and the metal pipe 2 are heated, and the temperature of each member rises. Column member 1
The metal pipe 2 starts to expand according to the respective linear expansion coefficients (FIG. 6). Thereafter, the metal pipe 2 shifts from the elastic region to the plastic region of the metal material due to the pressure from the cylindrical member 1 as the temperature rises, and the shape of the metal pipe 2 changes to the inverted crown shape of the cylindrical member 1 (FIG. 7). After the elapse of the heating time of 30 minutes, the heating is stopped, and the process proceeds to the cooling step (FIG. 8).

As shown in FIG. 9, the cooling in the cooling step is performed by cooling the metal pipe 2 and the columnar member 1 in a water tank 4 with water. In the present embodiment, after the heating, the metal pipe 2 is cooled at a cooling rate of 100 ° C./min.

Here, the step of releasing the obtained metal pipe 4 having the inverted crown shape will be described.

In the releasing step, the cylindrical member 1 is released from the metal pipe 2 as shown in FIG. The size of the central part of the metal pipe 4 taken out is 25.
068 mm, both ends 25.118 mm, 0.0
An inverted crown as large as 5 mm was formed with high accuracy.

Next, the usage of the metal pipe 4 manufactured by the above method will be described.

The metal pipe 4 obtained according to the present embodiment
An example in which the outermost layer is coated with a fluororesin paint by spraying or dipping and used as a fixing belt 6 of a fixing device of an image forming apparatus (LBP, copying machine, etc.) shown in FIG.

In FIG. 11, 6 is a metal pipe (fixing belt) according to the present invention, 6A is a heater for heating the fixing belt 6, and the heater 6A is held by a heater holder 6B. Reference numeral 6C denotes a stay member, which is formed in a substantially U-shape.

The fixing belt 6 is incorporated so as to be fitted on the outer peripheral surfaces of the stay member 6C and the heater holder 6B.

Reference numeral 6D denotes a pressure roller, and the pressure roller 6D is driven by driving means (not shown). The fixing device transports and inserts a carrier 6E such as paper carrying toner for forming an image between the fixing belt 6 and the pressure roller 6D as shown in the figure, and heats the fixing belt 6 received from the heater 6A. Is transferred to the toner, and the toner is fixed on the paper by pressing and heating. The fixing belt 6 according to the present invention has a very high uniformity of the thickness uniformity of the belt, and the belt from the toner to the toner. Very high image quality could be obtained without uneven heat transfer.

FIG. 12 shows a case where the metal pipe 6 according to the present invention is used as a transfer belt of an image forming apparatus.

In FIG. 12, reference numeral 7 denotes a photosensitive drum, reference numeral 10 denotes toner, and reference numeral 9 denotes a transfer belt in which both surfaces of a metal pipe are coated with a resin. By using a metal pipe (belt) coated with a double-sided resin as the transport belt, high-precision transport and high durability can be expected as compared with the performance of a conventional belt made of a resin or an elastomer alone.

Next, the material of the metal pipe applicable to this embodiment will be described.

As the material of the metal pipe 2 that can be used in the present invention, almost any material is suitable, and in particular, aluminum, copper, titanium, iron, beryllium, nickel, tin,
Examples include simple metal systems such as magnesium, chromium, and zinc, and various alloy systems such as stainless steel, brass, brass, phosphor bronze, bronze, and duralumin.

Examples of the material of the columnar member 1 include polyether ether ketone, polyphenylene sulfone, polysulfone, polyphenylene sulfide, polyimide, polyether sulfone, polystyrene, polypropylene, polybutylene, polybutylene terephthalate, polycarbonate, polyethylene terephthalate, polyphenylene oxide, Polybutadiene, polyallyl sulfone, polyamide imide, polyarylate, polyamide, nitrile resin, fluororesin, ketone resin, phenolic resin, polyacetal, amino resin, polyvinylidene chloride, polymethylpentene, epoxy resin, allyl resin, furan resin, methacrylic resin , Thermoplastic elastomer, polyurethane, polyvinyl chloride and the like.

Second Embodiment Next, a second embodiment of the present invention will be described.

The feature of the present embodiment is to make the thermal expansion of the cylindrical member anisotropic so as to increase the efficiency of the pressure applied to the metal pipe and to shorten the time required for forming the inverted crown of the metal pipe. Is to do.

Here, a specific embodiment is shown in FIG.

In FIG. 3, reference numeral 1 denotes a cylindrical member as a mandrel into which a metal pipe is inserted. In this embodiment, a solid rod member is used. Reference numeral 5 denotes a lid for restricting thermal expansion of the columnar member 1, and is provided at both ends. Reference numeral 2 denotes a tubular or hollow metal pipe having an inner diameter through which the cylindrical member 1 is inserted.

In this embodiment, the columnar member 1 is made of polyetheretherketone (PEEK), and the lid 5 and the metal pipe 2 are made of SUS304. The coefficient of linear expansion of PEEK is 4.5 × 1.
0 ^-5 (/ ° C.), the linear expansion coefficient of SUS304 is 1.7 × 1
0 ⁻⁵ (/ ° C.).

Next, a specific embodiment will be described.

The size of the columnar member 1 is selected according to the inner diameter of the metal pipe 2 to be manufactured. First, as the metal pipe 2, a SUS304 pipe, here having an inner diameter of 25.00 m, is used.
A piece cut to dimensions of m, thickness 0.1 mm and length 227.0 mm is prepared.

As shown in FIG. 2, the columnar member 1 has an inverted crown shape, and the diameter 1a at both ends is 24.95 mm and the diameter 1b at the center is 24.90 mm.

The dimensions of the cylindrical member 1 and the metal pipe 2 are set such that the outer diameter of the cylindrical member 1 is smaller than the outer diameter of the metal pipe 2 at a temperature of 150 ° C. during heating in a heating step described later. Design in advance so as to exceed .05 mm.

Here, as shown in FIG. 1, the cylindrical member 1 is inserted into the hollow portion of the metal pipe 2. Then, the cylindrical member 1 and the metal pipe 2 are inserted into the heating furnace 3 shown in FIG. The heating conditions in the heating furnace 3 are a heating temperature of 150 ± 5 ° C. and a heating time of 20 ± 1 minute.

In the heating step, the columnar member 1 and the metal pipe 2 are both heated, causing a difference in dimensional expansion due to a difference in the thermal expansion coefficient of the material, thereby reducing the gap between the metal pipe 2 and the metal pipe 2.
Is pressed from the inner surface by the column member 1 having an inverted crown shape to form an inverted crown shape. At this time, the direction of thermal expansion is limited only to the inside of the metal pipe 2 by the lids 5 attached to both ends of the columnar member 1, and the heating time is shortened by about 10 minutes as compared with the case without the lid 5. It has become.

After the above-mentioned heating step, it is taken out of the heating furnace 3 and
The cylindrical member 1, the lid 5, and the metal pipe 2 are cooled. The cooling in the cooling step is performed by water cooling the metal pipe 2 and the columnar member 1 in a water tank 4 as shown in FIG.

In the present embodiment, after the heating,
The cooling is performed at a cooling rate of 1 / min.

Here, the step of releasing the obtained metal pipe 4 having the inverted crown shape will be described.

In the releasing step, as shown in FIG. 9, the cylindrical member 1 is released from the metal pipe 2 by releasing. The size of the central part of the metal pipe 4 taken out is 25.
068 mm, both ends 25.118 mm, 0.0
An inverted crown as large as 5 mm was formed with high accuracy.

<Third Embodiment> Next, a third embodiment of the present invention will be described.

The feature of this embodiment is that the use of aluminum as the material of the cylindrical member 1 shortens the tact time and improves the durability of the mold.

FIG. 3 shows a specific embodiment.

In FIG. 3, reference numeral 1 denotes a cylindrical member serving as a mandrel into which a metal pipe is inserted. In this embodiment, a solid rod member is used. Reference numeral 2 denotes a tubular or hollow metal pipe having an inner diameter through which the cylindrical member 1 is inserted.

In this embodiment, the cylindrical member 1
Using aluminum, the lid 5 and the metal pipe
As SUS304, SUS304 is used. In addition, aluminum
Has a linear expansion coefficient of 2.4 × 10^-Five(/ ° C), SUS304
Has a linear expansion coefficient of 1.7 × 10 ^-Five(/ ° C.).

Next, a specific embodiment will be described.

The size of the columnar member 1 is selected according to the inner diameter of the metal pipe 2 to be manufactured. First, as the metal pipe 2, a SUS304 pipe, here having an inner diameter of 25.00 m, is used.
A piece cut to dimensions of m, thickness 0.1 mm and length 227.0 mm is prepared. As shown in FIG. 2, the columnar member 1 is an inverted crown in shape, the diameter 1a at both ends is 24.95 mm, and the diameter 1b at the center is 24.92.
mm.

The dimensions of the cylindrical member 1 and the metal pipe 2 are set such that the outer diameter of the cylindrical member 1 is smaller than the outer diameter of the metal pipe 2 at a temperature of 150.degree. It is designed in advance so as to exceed .03 mm.

Here, as shown in FIG. 1, the cylindrical member 1 is inserted into the hollow portion of the metal pipe 2. Then, the cylindrical member 1 and the metal pipe 2 are inserted into the heating furnace 3 shown in FIG. The heating conditions in the heating furnace 3 are a heating temperature of 200 ± 5 ° C. and a heating time of 20 ± 1 minute.

In the heating step, the cylindrical member 1 and the metal pipe 2 are both heated, causing a dimensional expansion difference due to a difference in the thermal expansion coefficient of the material to reduce the gap, and the metal pipe 2 has an inverted crown-shaped cylindrical member. 1 is pressed from the inner surface to form an inverted crown shape. At this time, by changing the cylindrical member 1 from a resin to a metal material such as aluminum, the thermal conductivity is improved, and the cylindrical member is quickly heated, and the
The heating time was shortened by about a minute.

After the above-mentioned heating step, it is taken out of the heating furnace 3 and
The cylindrical member 1 and the metal pipe 2 are cooled. As shown in FIG. 8, the cooling in the cooling step is performed by water cooling the metal pipe 2 and the columnar member 1 in the water tank 4.

In the present embodiment, after the heating,
The cooling is performed at a cooling rate of / min.

Here, a step of releasing the obtained metal pipe 4 having the inverted crown shape will be described.

In the releasing step, as shown in FIG. 9, the cylindrical member 1 is released from the metal pipe 2 by releasing. The size of the central part of the metal pipe 4 taken out is 25.
230 mm, both ends 25.200 mm, 0.0
An inverted crown as large as 3 mm was formed with high accuracy.

[0062]

As is apparent from the above description, according to the present invention, in a combination of materials in which the coefficient of linear expansion of a metal pipe is smaller than the coefficient of linear expansion of a cylindrical member, a straight metal pipe is formed into an inverted crown shape. Insert into the cylindrical member,
Since at least the cylindrical member is heated to form the metal pipe into an inverted crown shape, an effect that a straight metal pipe can be formed into an inverted crown shape with high precision and at low cost can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view when a metal pipe is inserted into a column member having an inverted crown shape.

FIG. 2 is an explanatory view of a column member having an inverted crown shape.

FIG. 3 is an explanatory view of a columnar member with a lid.

FIG. 4 is an explanatory view of a heating furnace in a heating step.

FIG. 5 is an explanatory diagram in a room temperature state when a metal pipe is inserted into a column member having an inverted crown shape.

FIG. 6 is an explanatory diagram in a temperature rising state when a metal pipe is inserted into a column member having an inverted crown shape.

FIG. 7 is an explanatory view in a state where the temperature is raised when a metal pipe is inserted into a column member having an inverted crown shape.

FIG. 8 is an explanatory view in a cooled state when a metal pipe is inserted into a column member having an inverted crown shape.

FIG. 9 is an explanatory diagram of a cooling step.

FIG. 10 is an explanatory diagram of a release step.

FIG. 11 is an explanatory diagram of a fixing device of an image forming apparatus using a metal pipe.

FIG. 12 is a sectional view of a main part of an image forming apparatus using a metal pipe for a transfer belt.

[Explanation of symbols]

 Reference Signs List 1 cylindrical member 2 metal pipe 3 heating furnace 4 water tank 5 lid 6 fixing belt 6A fixing belt heating heater 6B heater holder 6C stay member 6D pressure roller 6E carrier 7 photosensitive drum 8 fixing device 9 transfer belt 10 toner

Claims (13)

[Claims] In a combination of materials in which a coefficient of linear expansion of a metal pipe is smaller than a coefficient of linear expansion of a cylindrical member, a straight metal pipe is inserted into an inverted crown-shaped cylindrical member, and at least the cylindrical member is heated to heat the cylindrical member. A method for manufacturing a metal pipe, comprising forming the metal pipe into an inverted crown shape. 2. The method according to claim 1, wherein the thickness of the metal pipe is 1 mm or less. 3. The method according to claim 1, wherein the surface roughness of the metal pipe is within 5 μm. 4. The method according to claim 1, wherein a surface layer of the metal pipe has a toner releasing property. 5. A method for manufacturing a metal pipe, wherein an inner peripheral surface of the metal pipe has wear resistance. 6. The method according to claim 5, wherein fluorine or silicone resin is used as the wear-resistant material. 7. A method for manufacturing a metal pipe, comprising using an inorganic material as a wear-resistant material. 8. The method according to claim 7, wherein boron nitride, aluminum nitride, or diamond is used as the inorganic material. 9. An end face of the metal pipe having a surface roughness of 0.
The method for producing a metal pipe according to claim 1, wherein the diameter is within 1 mm. 10. The production of a metal pipe according to claim 1, wherein the difference in diameter between the center part and both ends in the longitudinal direction of the cylindrical member as the inverted crown-shaped cylindrical member is 1 μm or more and 100 μm or less. Method. 11. The method according to claim 1, wherein the material of the cylindrical member is a resin. 12. The method according to claim 1, wherein the material of the cylindrical member is metal. 13. The method for manufacturing a metal pipe according to claim 1, wherein a lid having a smaller linear expansion coefficient than the cylindrical member is provided on at least one end surface of the cylindrical member.