JP2740530B2 - Method of manufacturing elastic roller - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing an elastic roller having a protective sleeve on the outside containing a metal core, and more particularly to a roller for an electronic copying machine, a laser printer, or the like.

[Related Art and Problems to be Solved by the Invention] In recent years, heat rollers used in heat fixing units of electronic copiers and laser printers have been improved in speed, quality, image quality, and speed of electronic copiers and laser printers. With the demand for screens, energy savings and longevity, stable paper feedability has become a problem. As a roller that meets these demands, a multi-layered fixing roller, a pressure roller, or the like having a fluororesin layer on the surface that is easily separated from a toner that is a colored substance obtained by adding carbon black or the like to polyethylene or an acrylic acid polymer is used. Is now available. Of these rollers, the pressure roller was vulcanized and bonded with silicone rubber to the metal core, the surface was ground, and the outermost layer was coated with a mixed latex of fluoro rubber and fluoro resin via a primer and fired. But,
Foreign matter adhering or entering during the manufacturing process is often carbonized in the firing process, leading to protrusions or dents on the roller surface or pinholes in the surface layer film.

For this reason, a fluororesin tube, which is a sleeve with a diameter slightly smaller than this inner diameter, is fixed inside the cylindrical mold, a metal core is set up at the center, and liquid rubber is injected into the gap between the metal core and the sleeve to form the sleeve. A method is known in which, after expansion, the cylindrical mold is fired and vulcanized together with the cylindrical mold to produce it (Japanese Patent Publication No.
50-7097, JP-B-51-27276).

However, it is very difficult to fix a fluororesin tube having a diameter smaller than the inner diameter of the cylindrical mold to the cylindrical mold. In many cases, the liquid rubber flows into the gap between the mold and the mold, and the production efficiency is often lowered. In addition, a through-hole communicating with the outside world is provided in the mold fitted to the cylindrical mold, so that liquid rubber can be injected. However, if liquid rubber flows into this through-hole at the time of injection, the sleeve expands sufficiently. In such a state, curing cannot be performed, and wrinkles and the like remain, and creep occurs, resulting in a defective product. Also, when the liquid rubber is baked and vulcanized in the cylindrical mold, the cylindrical mold becomes airtight, and the expanded rubber intervenes in the fitting portion of the mold and the like, so that a uniform roller thickness cannot be obtained and a large touch failure occurs. There is a drawback that a roller is easily generated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of manufacturing an elastic roller which eliminates the above-mentioned disadvantages, has a uniform roller thickness, does not cause defective products, and can easily and efficiently manufacture an elastic roller having no run-out. And

[Means for Solving the Problems] The method for manufacturing an elastic roller according to the present invention is characterized in that a liquid elastic material is injected into a gap between a metal core and a sleeve coaxially fixed to the metal core in a cylindrical mold, and then heated. When manufacturing an elastic roller formed by integrally curing the metal core, the liquid elastic material and the sleeve, a pressure adjusting valve is provided in the cylindrical mold, and the pressure adjusting valve is provided when the liquid elastic material is injected. The pressure resistance is smaller than the liquid elastic material injection pressure, and is larger than the liquid elastic material expansion pressure at the time of heating and curing the liquid elastic material, and the sleeve is fixed around the cylindrical mold. I do.

[Operation] The method of manufacturing an elastic roller according to the present invention is characterized in that the inner diameter of the cylindrical mold is 95 to 98 so as to fit along the inner wall of the cylindrical mold having a metal core at the center.
% Of the sleeve is set, and the end of the sleeve protruding from the vertical direction of the cylindrical mold is folded back to the outside of the cylindrical mold and fixed at the outer peripheral part. Thereafter, liquid rubber, which is a liquid elastic material, is injected between the metal core and the sleeve from the lower part of the cylindrical mold. Since the sleeve covers the outer circumference of the cylindrical mold, the handling is very simple without liquid rubber flowing into the gap between the cylindrical mold sleeves.

In addition, a small hole is provided at the place where the rubber coating part of the cylindrical mold is removed, and air is released between the inner wall of the cylindrical mold and the sleeve when the liquid rubber is injected, and the liquid rubber is easily injected between the metal core and the sleeve. A pressure adjusting valve is provided on a cap (upper mold) provided on the upper part of the cylindrical mold, so that the pressure when the liquid rubber is injected between the sleeve and the metal core can be adjusted. Also, when heat curing after injection, the pressure is adjusted according to the expansion of the rubber.

[Embodiment] The manufacturing method of an elastic roller according to the present invention is applied to a pressure roller of a heat fixing unit of an electronic copying machine.

In the figure, a PFA tube 2 used as a fluororesin tube, which is a sleeve having a diameter of 95 to 98% of the inner diameter of the cylindrical mold 1, is inserted along the inner wall of the cylindrical mold 1. The PFA tube 2 is fixed at its upper and lower ends with the stopper 3 having a coefficient of friction larger than the coefficient of friction with the cylindrical mold 1, for example, an elastic body fastening member. . A conical cap 5 is provided at the upper and lower ends of a metal core 4 which is coaxially installed at the center of the cylindrical mold 1.
1 and 5-2 are provided, and the upper mold 6-1 and the lower mold 6-2 for fitting the caps 5-1 and 5-2, respectively, are fitted to the cylindrical mold 1. The lower mold 6-2 has a tapered portion 8 fitted to an injection port 7 of a liquid rubber 12 which is a liquid elastic material connected to an injection device (not shown). The upper mold 6-1 is provided with a pressure adjusting valve 9, and when a pressure equal to or higher than a predetermined pressure is applied, the valve is opened, and the internal pressure is adjusted. The rubber cover of the roller of the cylindrical mold 1 is removed, and a small hole 10 is provided near the boundary surface with the bottom surface of the upper mold 6-1. The air interposed in the gap can be released. The upper mold 6-1 and the lower mold 6-2 are engaged by a spring 11 so as to press against the expansion of the liquid rubber.

A method of manufacturing an elastic roller using the manufacturing apparatus having the above configuration will be described.

The inner surface of the cylindrical mold 1 was etched.
The PFA tube 2 is set, and the upper end and the lower end are turned out of the cylindrical mold 1 and fixed by the stopper 3. After the PFA tube 2 is fixed, a primer that promotes adhesion between the PFA tube 2 and the liquid rubber is applied to the inner surface. At this time
Since the PFA tube 2 is fixed, the processing steps can be performed very efficiently. Thereafter, the metal core 4 coated with the primer is capped with caps 5-1 and 5-2, fitted into the upper mold 6-1 and the lower mold 6-2, fixed to the same cylindrical mold 1, and fixed to the lower mold 1. 6-2 and the upper mold 6-1 are fastened by the spring 11.

When the injection port 7 is fitted into the tapered portion 8 provided in the lower mold 6-2, the metal core 4 is pushed upward together with the cap 5-2, and the lower mold 6-2 and the cap 5-2 are pushed up. The liquid rubber 12 is formed between the metal core 4 and the PFA tube 2 from the gap formed between
Injected in between. Liquid rubber 12 is of low viscosity type (100-200
0c.p.), but it is injected under pressure and the cylindrical mold 1 and P
Since the air interposed between the FA tubes 2 is released from the small holes 10, the air flows uniformly between the metal core 4 and the PFA tube 2. At this time, the liquid rubber injection pressure is greater than the pressure resistance of the pressure control valve, so that the liquid rubber extends the diameter of the PFA tube 2 and expands until it comes into close contact with the cylindrical mold 1. Cap 4 of core 4 and upper mold 6-1
When the pressure regulating valve 9 is pressed through the gap between the two and when the pressure received by the pressure regulating valve 9 reaches a certain pressure equal to or less than the pressure received by the upper and lower molds by the spring 11, the valve is opened and the liquid rubber 12 is ejected. As a result, it is found that the liquid rubber 12 has been filled between the metal core 4 and the PFA tube 2, and the injection is stopped. Then, the apparatus is left in a thermostatic oven to cure and cure the liquid rubber 12. At this time, the pressure of the pressure control valve is larger than the liquid rubber expansion pressure, and the rubber expands, but the expanded rubber can be released by the pressure control valve 9 to maintain a constant pressure. After the rubber is cured, it is cooled and removed from the mold to form an elastic roller.

Applying the elastic roller manufacturing method described above, inner diameter 50.5
Non-heat-shrinkable type 48.5mm, 50μ thickness
m PFA tube (Gunze Co., Ltd.)
m, 329 mm long iron-based metal core, KE1236, liquid rubber of 30 mm hardness (Shin-Etsu Chemical Co., Ltd.), heat cured and integrated, then cooled, demolded and heat treated at 200 ° C for 4 hours The elastic roller obtained by applying JIS-S6050 hardness tester is 62mm and runout is 0.20
It was of high quality of less than mm. This is an A4 copy machine
A practical paper passing test was conducted on 300,000 sheets while applying high-viscosity silicone in the mode. The results were also very good without peeling of the PFA film or occurrence of wrinkles.

The manufacturing method of the elastic roller according to the present invention, which is one embodiment in which the manufacturing method of the elastic roller described above is applied to the manufacturing of a pressure roller of an electronic copying machine, is not limited to this. It goes without saying that you can do it.

According to the elastic roller manufacturing method of the present invention, a sleeve having a diameter of 95 to 98% of the inner diameter of a cylindrical mold is used, and the sleeve is fixed on the outer periphery of the cylindrical mold. In addition, the liquid rubber can be produced very efficiently without flowing the liquid rubber between the cylindrical mold and the sleeve. In addition, since the pressure adjusting valve is provided in the cylindrical mold, the sleeve is sufficiently stretched even when injecting the rubber, so that the rubber can be injected without excess or shortage. Even during thermosetting, the rubber expands and intervenes in the fitting portion of the mold. Nothing. Therefore, it is possible to manufacture a uniform and durable elastic roller having no vibration.

[Brief description of the drawings]

The drawing is a schematic sectional view of a manufacturing apparatus of one embodiment to which the method of manufacturing an elastic roller according to the present invention is applied. 1 Cylindrical mold 2 Sleeve (fluororesin tube) 9 Pressure regulating valve 12 Liquid elastic material (liquid rubber)

Continuation of the front page (51) Int.Cl. ⁶ Identification code FI B29L 31:00 (72) Inventor Kazuhisa Ishikawa 2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Showa Electric Wire & Cable Co., Ltd. (72) Invention Person Shuji Ima 2-1, 1-1 Oda Sakae, Kawasaki-ku, Kawasaki-ku, Kanagawa Prefecture Inside Showa Electric Wire & Cable Co., Ltd. (72) Inventor Toshio Kida 2-1-1 Oda-Ei, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture, Japan Showa Electric Wire & Cable Co., Ltd (72) Inventor Yasuhisa Kudo 2-1-1 Oda Ei, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside Showa Electric Wire & Cable Co., Ltd. (56) References JP-A-62-28213 (JP, A) JP-A-62-30011 ( JP, A) JP-A-62-183314 (JP, A)

Claims (2)

(57) [Claims] 1. A liquid elastic material is injected into a gap between a metal core and a sleeve fixed coaxially with the metal core in a cylindrical mold, and then heated and cured to remove the metal core, the liquid elastic material and the sleeve. When manufacturing an elastic roller formed integrally, a pressure adjusting valve is provided on the cylindrical mold, and when the liquid elastic material is injected, the pressure resistance of the pressure adjusting valve is smaller than the liquid elastic material injection pressure, and the liquid A method for manufacturing an elastic roller, wherein the elastic roller is larger than the expansion pressure of the liquid elastic material during heat curing of the elastic material. 2. The method according to claim 1, wherein said sleeve is fixed around said cylindrical mold.