JPH05329848A - Apparatus for producing tube coated roller - Google Patents

Abstract

PURPOSE:To produce a tube coated roller with a good yield. CONSTITUTION:A tube 17 is fitted to a cylindrical mold 22 so as to be folded from the inner wall of the mold 22 to the outer wall thereof and upper and lower molds 27, 26 are fitted to the cylindrical mold 22 to hold the tube 17 between the outer wall of the cylindrical mold 22 and the inner wall of the upper mold 27 or that of the lower mold 26. Protruding parts 37 are provided to the upper and lower molds 27, 26 so that the upper and lower molds 27, 26 come into contact with the cylindrical mold 22 through the tube 17. The protruding parts 37 separate the part where liquid rubber is bonded to the tube 17 and an excessive part. Thereafter, the liquid rubber is heated and cured to produce a tube coated roller. By this constitution, at the time of demolding, it is prevented that the end part of the tube 17 is pulled to generate wrinkles. Therefore, the tube coated roller can be produced with a good yield.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a tube-covered roller for a roller used in a toner fixing portion of a laser printer, an electronic copying machine or the like.

[0002]

2. Description of the Related Art Conventionally, a toner fixing section of an electronic copying machine or a laser printer is composed of a heating roller having a heater inside and a pressure roller. The copy paper that passes through is pressed and the toner is fixed on the copy paper for printing. The roller of such a fixing unit is required to have appropriate elasticity and good releasability from the toner in order to stabilize the sheet passing and obtain a clear image. In addition, the speed of electronic copiers and leather printers equipped with a fixing roller is increased.
With the demand for miniaturization, miniaturization and high speed have become problems. Therefore, with a single-layer roller having only the elastic body on the cored bar, a roller with low hardness that can secure the nip width, smooth surface, good paper passage property, and excellent durability that does not easily wear can be obtained. There wasn't. Therefore, a roller having a multi-layer structure is used in which an elastic body having appropriate elasticity is provided on a cored bar, and an outermost layer having good releasability is laminated on the elastic body.

Since the roller having such a multilayer structure is heated to a considerably high temperature, it must have heat resistance and good thermal conductivity. Silicone rubber or fluororubber is used as an elastic body, and the outermost layer is used. As such, fluororesins such as perfluoroalkoxy resin (PFA resin) and polytetrafluoroethylene resin (PTFE resin) are adopted. To manufacture a roller with a multi-layer structure, the outermost layer of fluororesin is molded into a tube in advance, and then an elastic roller with an elastic body such as silicone rubber that provides the desired nip width formed on a core is inserted into this tube. Alternatively, the liquid rubber is injected into the tube arranged on the inner wall of the mold, and then the mold is heated to cure the liquid rubber and the tube and the elastic body are integrated to manufacture the tube covering roller.

[0004]

As shown in FIG. 3, the apparatus for manufacturing the fixing section roller is provided with a cylindrical mold 2 having a fluororesin tube 1 attached to the inner wall surface thereof. Both ends are folded back and installed on the outer wall surface of the cylindrical mold 2. Conical caps 4 are provided on the upper and lower ends of the cored bar 3 coaxially installed at the center of the cylindrical mold 2. Further, each is provided with a fitting portion 5 for fitting the core metal 3 with the cap 4 fitted therein, and by fitting the cap 4 into the fitting portion 5, the core metal 3 is sandwiched coaxially with the cylindrical mold 2. A lower mold 6 and an upper mold 7 are provided. The lower mold 6 is provided with a rubber injection port 10 that fits with an injection port 9 of a liquid rubber 8 connected to an injection device (not shown). Further, the upper mold 7 is provided with a pressure adjusting valve 12 having a leaf spring 11, and when the liquid rubber 8 is injected or vulcanized, a valve having a certain pressure or more is opened, and the internal pressure is increased. It is supposed to be adjusted. An air escape path (not shown) may be formed in the pressure control valve 12 when the liquid rubber is injected. The upper die 7 and the lower die 6 have a protrusion 13 and are fixed to each other by a spring 14 hooked on the protrusion 13.

In order to manufacture a tube coating roller using such a roller manufacturing apparatus, a tube is attached to a cylindrical mold, a core metal 3 is inserted, and upper and lower molds 6 and 7 are set. The liquid rubber 8 is injected from the liquid rubber inlet 10 until the pressure adjusting valve 12 is pushed up. Then, the liquid rubber 8 is hardened by leaving it in a temperature tank for each mold. After curing, the tube coating roller was obtained by releasing from the mold.

However, when the molded product is released from the mold, when the upper and lower molds 6 and 7 are removed from the cylindrical mold 2, the cylindrical mold 2 and the upper and lower molds 6 and 7 hold the molded product. The part of the fluororesin tube 1 is pulled. For this reason, wrinkles may occur at the end of the product, and the yield of the product deteriorates. The present invention has been made in order to solve the above-mentioned drawbacks, the load is not applied to the tube when the mold is released from the mold, therefore wrinkles do not occur at the end of the tube, and it is possible to manufacture a tube covered roller with good yield. An object of the present invention is to provide an apparatus for manufacturing a tube coating roller.

[0007]

In order to achieve the above-mentioned object, in the tube covering roller manufacturing apparatus of the present invention, a cylindrical mold having a tube attached to its inner wall is fitted to the upper and lower sides of the cylindrical mold, respectively. An upper die and a lower die that clamp the end of the tube with the cylindrical die and fix a cored bar inserted into the cylindrical die coaxially, and the lower die are provided with the upper die and the lower die. In a tube covering roller manufacturing apparatus comprising a core metal and a liquid rubber injection port for injecting a liquid rubber between the tubes, the upper mold and the lower mold have the tubes from the inner wall to the outer wall of the cylindrical mold. It has a protruding portion that is in contact with the radial end of the liquid rubber over the circumference of the portion that is attached and folded back.

[0008]

Function: A tube is attached to the inner wall of the cylindrical mold, the end of the tube is folded back to the outer wall of the cylindrical mold, and the folded back end is formed on the outer wall of the cylindrical mold and the inner walls of the upper mold and the lower mold. And clamp the core metal coaxially with the cylindrical mold. In the upper mold and the lower mold, since the tube attached to the inner wall of the cylindrical mold is folded back to the outer wall, a protruding portion is provided along the circumference, so that the liquid rubber pouring on the lower mold is performed. The liquid rubber injected from the inlet between the core metal and the tube is divided into a tube surface and a surplus portion for forming by the protrusion. Therefore, after heating the liquid rubber to cure it into an elastic body,
When removing the upper and lower molds from the cylindrical mold, a load is applied to the end of the tube folded back to the outer wall of the cylindrical mold, but no load is applied to the tube in the portion bonded to the elastic body. Further, since the elastic body has a portion bonded to the tube and a surplus portion separated, no load is applied to the portion bonded to the tube at the time of mold release. Therefore, wrinkles do not occur at the end of the roller, and the roller can be manufactured with high yield.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the tube covering roller manufacturing apparatus of the present invention is applied to a pressure roller of a fixing section roller of an electronic copying machine will be described with reference to the drawings. As shown in FIG. 1, the pressure roller R, which is a tube-covering roller, has a core metal 15 on which an elastic layer 16 and a fluororesin layer 17 made of a tube as an outermost layer are bonded and integrated.

The cored bar 15 is made of a material having good adhesion to the elastic layer 16, such as iron or aluminum. Core 1
It is preferable that the elastic layer 16 formed on the sheet 5 is less deteriorated by heat, and has appropriate elasticity so as to satisfy the paper passing property, and silicone rubber, fluororubber or the like is used. Silicone rubber is used because it is less likely to be deteriorated by heat. The elastic layer 16 is made of liquid rubber such as addition reaction type silicone rubber (LTV silicone rubber) and condensation reaction type silicone rubber (RTV silicone rubber) which can be injected and cured when forming the tube covering roller. The elastic layer 16 has semiconductivity so that the toner can be easily released, and carbon black or the like is appropriately added. Further, other filler may be added to the elastic layer 16.

Further, the fluororesin layer 17 serving as the outermost layer has little deterioration due to heat, has excellent releasability from the toner, and has a small coefficient of friction, and it has a polyfluoroalkoxy resin (PFA resin) or polytetrafluoroethylene. Resin (PT
FE resin) or the like is formed in advance in a tube.
To manufacture the pressure roller R having such a structure, the roller manufacturing apparatus S shown in FIG. 2 is used. The manufacturing apparatus S includes a cylindrical mold 22 having a fluororesin tube 17 attached to its inner wall surface. The fluororesin tube 17 has a diameter of 95 to 98% of the inner diameter of the cylindrical mold 22, and both ends thereof are
It will be installed by being folded back on the outer wall of the. Although not shown, a fixture for fixing the folded back end may be provided. A cored bar 15 installed coaxially at the center of the cylindrical mold 22.
Conical caps 24 are provided at the upper and lower ends, respectively. Further, fitting parts 25 for fitting the cored bar 15 fitted with the cap 24 are provided respectively, and by fitting the cap 24 to the fitting part 25, the cored bar 15 is sandwiched coaxially with the cylindrical mold 22. A lower mold 26 and an upper mold 27 are provided. The lower mold 26 has a rubber injection port 30 that fits with an injection port 29 of the liquid rubber 8 connected to an injection device (not shown).
Is provided. Further, the lower push plate 31 and the upper push plate 32 for fixing the lower mold 26 and the upper mold 27 to each other are provided with nuts 34.
Is connected to a desired position of the support column 33. Lower push plate 31
A liquid rubber injection port 35 is provided at a position corresponding to the rubber injection port 30 of the lower mold 26, and an internal pressure adjusting port 36 is provided at the center of the upper push plate 32. At the time of injecting the liquid rubber or at the time of vulcanization, the gap between the lower push plate 31 and the upper push plate 32 is adjusted by the nut 34, and the pressure between the core metal 15 and the fluororesin tube 17 is adjusted.

The lower mold 26 and the upper mold 27 of such a roller manufacturing apparatus S are mounted on the inner wall of the cylindrical mold 22 where the cylindrical mold 22 abuts via the fluororesin tube 17. Further, a projecting portion 37 is provided along the circumference of the portion where the end of the fluororesin tube 17 is attached to the outer wall of the cylindrical mold 22 and folded back. The protruding portion 37 abuts on the radial end of the elastic body 16 and separates a surplus liquid rubber at the time of forming the elastic body and a portion bonded to the fluororesin tube.

In order to manufacture the pressure roller R using such a manufacturing apparatus S, the fluororesin tube 17 is attached to the inner wall of the cylindrical mold 22. Further, after blasting and degreasing, an adhesive having good adhesiveness with the elastic layer 16 is applied, and the core metal 15 fitted with the cap 24 is inserted into the cylindrical mold 22. The upper mold 2 by fitting the cap 24 into the fitting portion 25
7 and the lower die 26 are fitted into the cylindrical die 22 to form the core 15
Is fixed coaxially, and the fluororesin tube 17 is attached to the outer wall of the cylindrical mold 22 and the upper mold 27 or the lower mold 26.
It is clamped and fixed by the inner wall of. At this time, the fluororesin tube 17 attached to and bent from the inner wall of the cylindrical mold 22 to the outer wall is brought into contact with the protrusion 37. At this time, the protrusion 37
Is a fluororesin tube 1 corresponding to the thickness of the cylindrical mold 22.
7 is abutted, and the protruding portion is left. Then, the lower push plate 31 and the upper push plate 32 are connected by a column, and the lower die 26 and the upper die 27 are sandwiched by the cylindrical die 22 and fixed with a nut 34 at a desired interval. After that, the injection port 29 of the liquid rubber 8 is fitted into the liquid rubber injection port 35 of the lower push plate 31, and the LTV is
Inject liquid rubber such as silicone rubber. Then, the liquid rubber 8 is injected from the internal pressure adjusting port 36 of the upper pressing plate 32 until it flows out. At this time, the liquid rubber 8 is separated by the projecting portion 37 which is in contact with the fluororesin tube 17 and further projects. After that, the mold is left in a thermostatic chamber at a desired temperature for a desired time, the liquid rubber 8 is cured, and the elastic layer 16 is formed by being bonded to the fluororesin tube 17. When removing the lower mold 26 and the upper mold 27 from the cylindrical mold 22 at the time of demolding, the end portion of the fluororesin tube 17 has an elastic layer 16
The part bonded to is not pulled. Moreover, since the elastic body layer 16 adhered to the fluororesin tube 17 and the surplus elastic body layer 16 not adhered to the fluororesin tube 17 are separated by the protrusions 37, the elastic body layer 16 can be easily divided. Is not applied to separate the elastic layer 16 from the elastic layer 16. Therefore, wrinkles do not occur in the fluororesin tube 17 during release. Therefore, the pressure roller R can be manufactured with good yield.

The above description is an explanation of one embodiment of the present invention, and the present invention is not limited to the pressure roller, but can be applied to any tube covering roller which is required to have heat resistance and elasticity. ..

[0015]

As is apparent from the above description, according to the apparatus for manufacturing a tube-covered roller of the present invention, the lower metal mold fitted with the cylindrical metal mold in which the tube is bent from the inner wall to the outer wall and mounted. By providing the protrusions over the inner circumferences of the mold and the upper mold, it is possible to manufacture the tube-covered roller with good yield without causing wrinkles at the ends of the tube when the mold is released from the mold.

[Brief description of drawings]

FIG. 1 is a sectional view of a tube coating roller formed by a tube coating roller manufacturing apparatus of the present invention.

FIG. 2 is a cross-sectional view showing an embodiment to which the tube coating roller manufacturing apparatus of the present invention is applied.

FIG. 3 is a cross-sectional view of a conventional tube coating roller manufacturing apparatus.

[Explanation of code] 8 ... liquid rubber 15 ... core metal 17 ... fluororesin tube (tube) 22 ... cylindrical mold 26 ... lower mold 27 ... upper mold 30 ... liquid rubber inlet 37 Protrusion R: Pressure roller (tube coating roller) S: Tube coating roller manufacturing device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical display location B29L 31:32 4F (72) Inventor Keiji Sato 2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa No. 1 in Showa Cable Denki Co., Ltd. (72) Inventor Junichi Fukahori 2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki-ku, Kanagawa Prefecture Sakae 2-1-1 No. 1 Showa Electric Cable Co., Ltd.

Claims (1)

[Claims] 1. A cylindrical mold having a tube attached to an inner wall thereof,
An upper mold and a lower mold that fit the upper and lower sides of the cylindrical mold, sandwich the end portion of the tube with the cylindrical mold, and coaxially fix a cored bar inserted into the cylindrical mold. In the apparatus for manufacturing a tube-covered roller, which is provided in the lower mold and includes a liquid rubber injection port for injecting liquid rubber between the core metal and the tube, the upper mold and the lower mold are the tubes. A tube-covered roller, characterized in that it has a protrusion that abuts the radial end of the liquid rubber over the circumference of the portion that is attached to the outer wall of the cylindrical mold and folded back. apparatus.