JP2002364632A - Manufacturing method of inverted crown roller, and thermal fixing roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inverted crown roller manufacturing method capable of stably working even a thin inverted crown roller to be formed with a small quantity of the inverted crown, and also capable of further curtailing the manufacturing cost. SOLUTION: In this method of manufacturing the inverted crown roller for a fixing roller using a metal pipe (aluminum pipe 11a) as a raw material and formed with a diameter continuously increased from the center of the center axis toward both ends, cramp members 12a and 12b for cramping the both ends of the metal pipe at parts not to be formed into an inverted crown shape are relatively moved on the metal pipe center axis, and the whole of a part to be formed into the inverted crown shape is plastically deformed to form the peripheral surface of the metal pipe (aluminum pipe 11a) into the inverted crown shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an inverted crown roller used for OA equipment such as a copying machine and a facsimile, and a heat fixing roller manufactured by the method.

[0002]

2. Description of the Related Art In an electrophotographic apparatus such as a copying machine and a facsimile / LBP, a fixing device of a fixing roller system is used. In such a fixing roll fixing device, an inverted crown-shaped fixing roller in which the outer diameter at the center is several hundreds to several tens μm smaller than the outer diameter at both ends is widely used in order to improve paper passing performance (especially preventing paper wrinkling). Have been.

In recent years, as the accuracy of the apparatus has been improved, the thickness of the roller core metal has been reduced in accordance with the improvement in accuracy of the inverted crown shape and energy saving. Such a fixing roller uses a core metal made of aluminum or steel having an inverted crown shape in outer periphery, and its surface layer is coated with a highly releasable fluororesin or silicon rubber, and a bearing and a drive gear are provided at both ends of the roller portion. Are formed.

Conventionally, a core metal having an inverted crown shape has been manufactured by cutting with a lathe. In this cutting process,
An inverted crown roller having a desired crown ratio is manufactured by using a metal pipe having a diameter larger than the reference outer dimension and cutting the outer periphery of the roller using a lathe.

[0005] In other than cutting, the tube is gripped by a clamp member and rotated in a direction parallel to the center axis of the tube while rotating around the center axis and pressing the forming roller against the tube. A method is known in which the pipe is moved in the radial direction of the pipe to plastically deform the pipe in the radial direction (see Japanese Patent Application Laid-Open No. 4-105720).

A two-part mold having an inner surface of a desired inverted crown shape is arranged on the outside of the tube, and the tube is arranged therein. The end of the tube is sealed, and a high-pressure fluid is press-fitted into the inside. And a method using a bulging process in which the outer surface of a tube is made to conform to the inner surface of a mold (see Japanese Patent Application Laid-Open No. 8-123231).

In addition, a heated thin-walled tube material to be machined is fitted on the outside using an inner mold having a thinner center portion and a thicker end portion. The diameter of the inner die made of a material having a low linear expansion coefficient is formed in a substantially inverted crown shape excluding the support surface, and after heating and loosely fitting the thin-walled tube, the inner peripheral surface of the thin-walled tube is cooled to form the inner die. A method of manufacturing a reverse-crown-shaped roller by re-heating the thin-walled tube material to expand the diameter thereof and extracting it from the inner mold (see Japanese Patent Application Laid-Open No. 10-128434). Are known.

[0008]

However, the manufacturing method by cutting has an advantage that high accuracy can be obtained.
Cutting had to be performed using a thick tube, and there was a disadvantage that the production cost was high due to the generation of chips. In addition, when aluminum is used as the roller material, aluminum for general use is a difficult-to-cut material, and therefore, in order to form an inverted crown shape by cutting, an aluminum material that is easy to cut must be used. Aluminum materials that are easy to produce are expensive, which further increases the manufacturing cost. In the cutting process, problems such as vibration and chatter occur as the thickness of the roller becomes thinner, and the process becomes more difficult.

In bulge processing, which is one of the methods of manufacturing a crown roller other than cutting, a high-pressure apparatus and a high-pressure-resistant molding die are used to form the crown roller, which increases the equipment cost and increases the manufacturing cost.

[0010] Further, as another manufacturing method, a method of plastically deforming the tube material in the radial direction while rotating the tube material by a forming roller, or a method of loosely fitting a heated thin-walled tube material in an inverted crown-shaped inner mold and then cooling it. In a method in which the inner peripheral surface of the thin-walled tube is closely formed by following the outer peripheral surface of the inner mold, and the thin-walled tube is reheated and pulled out from the inner mold, an inverted crown in which the difference in outer diameter between the center and the end of the tube is small. In the case of a roller, it is difficult to obtain a sufficient amount of deformation for plastic deformation, and it is difficult to perform the processing with high accuracy, and problems such as deformation return occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to manufacture a reverse crown roller which can be processed stably even with a small thickness and a small reverse crown amount, and can further reduce the manufacturing cost. A method and a heat fusing roller are provided.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a reverse crown roller for a fixing roller which is made of a metal pipe and whose outer diameter continuously increases from the center substantially from the center to both ends. In the manufacturing method, a member for clamping both ends of the metal pipe in a portion that does not have an inverted crown shape is relatively moved on the center axis of the metal pipe, and the entire portion of the metal pipe having the inverted crown shape is plastically deformed to thereby form a metal. The outer peripheral surface of the pipe is formed in an inverted crown shape.

Further, the present invention is characterized in that a heat fixing roller is formed by using a metal pipe having an inverted crown shape manufactured by the above-described method for manufacturing an inverted crown roller as a core metal.

Therefore, according to the present invention, the thinner the pipe thickness, the less the force used for deformation is required, so that the jig and the like can be simplified, and even a thin and small roller having a small inverted crown amount can be stably reduced. Can be manufactured at cost.

Since the inner and outer diameters of the clamp member are fixed, the outer diameter does not change. However, when the other clamp member is pulled on the center axis of the metal pipe, the unfixed portion of the pipe undergoes plastic deformation. As a result, the center portion of the non-fixed portion becomes thinner, and as a result, the metal pipe has an inverted crown shape. At this time, since a sufficient amount of plastic deformation is performed on the deformed portion even with a small amount of inverted crown, no problem such as return occurs.

Although the outer diameter of the clamp member does not change because the inner and outer diameters of the metal pipe are fixed, the other clamp member is rotated in the circumferential direction about the central axis of the metal pipe to thereby prevent the pipe from being disturbed. The fixed part is torsionally plastically deformed,
The central portion of the non-fixed portion becomes thinner, and as a result, the metal pipe has an inverted crown shape. At this time, since a sufficient amount of plastic deformation is possible in the deformed portion even with a small reverse crown amount, no problem such as return occurs.

By inserting a mold of a desired inverted crown shape inside the metal pipe in advance and plastically deforming along the mold, variations in the inverted crown shape due to unevenness in the thickness of the metal pipe can be suppressed. , More precise processing becomes possible.

[0018]

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

<Embodiment 1> In order to verify the effects of the present invention, an inverted crown roller using aluminum as a metal pipe was manufactured as follows. FIG. 1 shows a schematic diagram of the configuration of the first embodiment of the present invention.

First, the outer shape is 30 mm, the thickness is 1 mm, and the length is 3
A 10-mm straight aluminum pipe 11a was fixed at both ends 10 mm each with clamp members 12a and 12b so that the shape was not changed. The clamp member 12a has a central axis 13 extending on the central axis of the metal pipe 11, and the clamp member 12b has a central axis 1 at its center.
3 is free to move on the axis.

In consideration of deformation due to gravity, the clamp member 1
2a was suspended in a hot-air circulation oven. At this time, the clamp member 12b weighs 1 kg including its own weight. The temperature of the oven was set at 400 ° C. for about 30 minutes so that the aluminum pipe could be deformed even under a low load. Thereafter, the temperature is returned to room temperature and the clamp members 12a, 12b
After removing, when measuring the outer diameter, both ends are outer diameter 30m
m, the central crown was a 29.9 mm inverted crown of about 100 μm. The length at this time was about 302 mm.

<Embodiment 2> In order to verify the effects of the present invention, an inverted crown roller using aluminum as a metal pipe was manufactured as follows. FIG. 2 shows a schematic diagram of the configuration of the second embodiment of the present invention.

First, an outer diameter of 30 mm, a thickness of 1 mm, and a length of 3
Both ends of 00mm straight aluminum pipe 21a
Each 0 mm was fixed by the clamp members 22a and 22b so that the shape did not change. The clamp member 22a has a central axis 23 extending on the central axis of the metal pipe 21, and the clamp member 22b has a central axis 23 at the center thereof and is freely movable and rotatable on the axis. The central shaft 23 is fixed to the base 24, and the pipe 21 is
The clamp member 22b was placed in a hot air circulating oven with the arm raised, and a torque of 3 kg · cm was applied to the clamp member 22b in the rotation direction by a spring (not shown).

The oven temperature is set to 400 ° C. for about 30 minutes so that the aluminum pipe can be deformed even at a low torque.
I left it. Thereafter, the temperature is returned to room temperature and the clamp members 22a,
After removing 22b, the outer diameter was measured, and it was found that the opposite ends were an inverted crown of about 100 μm with an outer diameter of 30 mm and a center almost 29.9 mm. In this case, the length is about 300m
m, the twist was about 5 °.

<Embodiment 3> In order to verify the effect of the present invention, an inverted crown roller using aluminum as a metal pipe was manufactured as follows. FIG. 3 shows a schematic diagram of the configuration of the third embodiment of the present invention.

First, an outer shape of 30 mm, a thickness of 1 mm, and a length of 3
Both ends l of 00mm straight aluminum pipe 31a
Each 0 mm was fixed by the clamp members 32a and 32b so that the shape did not change. The clamp member 32a has an inverted crown shape (an inverted crown amount of 50 μm) having a desired outer diameter also serving as a central axis extending on the central axis of the metal pipe 31, and an inner die 36 that can be divided at the thinnest portion at the center. The sliding portion of the inner die 36 passes through the center of the clamp member 32b, and is freely movable and rotatable on the shaft.

The inner mold 36 was fixed to a table 34, and was placed in a hot-air circulation oven in a state where the pipe 31 was raised in consideration of deformation due to gravity. At this time, a torque of 3 kg · cm was applied to the clamp 32b in the rotation direction by a spring (not shown). The oven temperature is set to 400 ° C so that the aluminum pipe can be deformed even at low torque.
Left for 0 min. Then, after returning to room temperature, the inner mold 36 is divided and the clamp members 32a and 32b are removed.
6 was taken out and the outer diameter of the pipe was measured. Both ends were 30 mm in outer diameter and the central part was 29.95 mm. The length at this time was about 302 mm.

Embodiment 4 In order to verify the effects of the present invention, a heat fixing roller shown in FIG. 4 was manufactured as follows.

The 100 μm manufactured according to the second embodiment
A key groove for gear attachment and a groove for set ring are machined at both ends of an aluminum pipe 41b having an inverted crown amount of m, and Teflon (registered trademark) primer 855-312 is spray-coated about 5 μm as a primer 47 on a tube covering portion. Then, it was baked at 400 ° C. for 10 minutes. In the state cooled to room temperature, a heat-shrinkable tube 48 of PFA having substantially the same diameter and a thickness of 30 μm was covered, and fusion was performed at 350 ° C. for 30 minutes to produce a fixing roller.

The resulting heat-fixing roller maintained its inverted crown shape of 100 μm. When put into an actual machine, the fixing property was good, and good paper transportability without paper wrinkling was obtained. In addition, no change with time such as shape return was observed. In this embodiment, the key groove for mounting the gear and the groove for the set ring are processed later, but these may be processed before forming the inverted crown shape.

[0031]

As is apparent from the above description, according to the present invention, there is provided an inverted crown roller for a fixing roller which is made of a metal pipe and whose outer diameter continuously increases from substantially the center of the central axis toward both ends. In the manufacturing method, a member for clamping both ends of the metal pipe in a portion that does not have an inverted crown shape is relatively moved on the center axis of the metal pipe, and the entire portion of the metal pipe having the inverted crown shape is plastically deformed to thereby form a metal. Since the outer peripheral surface of the pipe is formed in an inverted crown shape, an effect is obtained that even an inverted crown roller having a small thickness and an inverted crown amount can be stably manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a method for manufacturing an inverted crown roller according to Embodiment 1 of the present invention.

FIG. 2 is a cross-sectional view illustrating a method for manufacturing an inverted crown roller according to Embodiment 2 of the present invention.

FIG. 3 is a cross-sectional view illustrating a method for manufacturing an inverted crown roller according to Embodiment 3 of the present invention.

FIG. 4 is a cross-sectional view of the heat fixing roller according to the present invention.

[Explanation of symbols]

 11a, 21a, 31a Aluminum pipe (before processing) 11b, 21b, 31b Aluminum pipe (after processing) 12a, 22a, 32a Clamp member (fixed side) 12b, 22b, 32b Clamp member (movable side) 13, 23 Center Shaft 24, 34 units 36 Inner die 41b Aluminum pipe (after processing) 47 Primer 48 PFA tube

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideo Kawamoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Inventor Osamu Satsuki 3-30-2 Shimomaruko, Ota-ku, Tokyo Kyano (72) Inventor Kazuo Kishino 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term (reference) 2H033 AA31 BB01 BB02 BB12 BB26 BB28 BB29 BB30 BB31 3J103 AA07 AA24 AA51 EA02 FA15 GA02 GA57 GA60 GA66 HA03 HA32 HA37 HA43 HA54

Claims (5)

[Claims] 1. A method of manufacturing an inverted crown roller for a fixing roller, wherein a metal pipe is used as a material and whose outer diameter continuously increases from a center substantially from a center to both ends, wherein both ends of the metal pipe at a portion which does not have an inverted crown shape are provided. The outer peripheral surface of the metal pipe is formed into an inverted crown shape by relatively moving the member that clamps the portion on the center axis of the metal pipe and plastically deforming the entire inverted crown shape of the metal pipe. Method of manufacturing an inverted crown roller. 2. An outer peripheral surface of the metal pipe by fixing one end of the clamp member and extending the other end on the center axis of the metal pipe, so that the entire portion of the metal pipe having an inverted crown shape is extended plastically deformed. The method according to claim 1, wherein the roller is formed in an inverted crown shape. 3. The metal pipe is formed by fixing one end of a clamp member and rotating the other end in the circumferential direction around the center axis of the metal pipe, thereby torsionally plastically deform the entire inverted-crown portion of the metal pipe. The outer peripheral surface of the pipe is formed in an inverted crown shape.
Or a method for producing an inverted crown roller according to item 2. 4. A method according to any one of claims 1 to 3, wherein a mold having a desired inverted crown shape is inserted into the inside of the metal pipe in advance, and the inside of the metal pipe is plastically deformed so as to follow the mold. The method according to claim 1, 2, or 3, wherein the outer peripheral surface of the metal pipe is formed in an inverted crown shape by extracting an inner mold after the operation. 5. A heat fixing roller using a metal pipe having an inverted crown shape manufactured by the method for manufacturing an inverted crown roller according to claim 1 as a core metal.