JP3137355B2 - Roller manufacturing equipment - Google Patents

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 an elastic roller having a protective sleeve on the outer periphery thereof, and more particularly to a roller for an electronic copying machine, a laser printer or the like.

[0002]

2. Description of the Related Art In recent years, a heat roller used in a heat fixing unit of an electronic copying machine, a laser printer, or the like has been required to have a stable paper-passing property in accordance with a demand for higher speed, higher image quality, and automatic double-sided printing. It has been a problem. As a roller that meets these requirements, a multi-layered fixing roller, a pressure roller, or the like having a fluororesin layer having a good releasability from a toner obtained by adding a carbon black or the like to a polyethylene or acrylic acid polymer on the surface may be used. Became. Of these rollers, the pressure roller was made by vulcanizing and bonding silicone rubber to the metal core, then grinding the surface, coating the outermost layer with a mixed latex of fluororubber and fluororesin via a primer, and firing it. In addition, foreign substances adhering or entering during the manufacturing process are often carbonized in the firing process, resulting in protrusions and dents on the roller surface or pinball on the surface layer.

For this reason, a sleeve of a fluororesin tube having a diameter slightly smaller than the inner diameter is inserted into the inside of a cylindrical mold, and liquid rubber is pressed between core shafts to expand the sleeve. Method of vulcanization and integral molding
0-7097, Japanese Patent Publication No. 51-27276)
It has been known.

[0004]

However, it is difficult to fix a sleeve having a diameter smaller than the inner diameter of the cylindrical mold. Further, when a low-viscosity liquid rubber is injected between the core shaft and the sleeve, the sleeve and the cylinder cannot be fixed. In many cases, the liquid rubber flows between the molds, resulting in a decrease in work efficiency.

For this purpose, as shown in FIG. 4, the end of the sleeve 3 attached to the inner wall of the cylindrical mold 2 coaxial with the core shaft 1 is fixed to the outer wall of the cylindrical mold 2 by a pressing member 4, There is a mold in which caps 5 respectively fitted to upper and lower ends of the core shaft 1 are fitted, and an upper mold 6 and a lower mold 7 which are fitted in the cylindrical mold 2 are provided. The lower mold 7 has an inlet 8 connected to a liquid rubber supply device (not shown), and the upper mold 6 has a pressure adjustment for adjusting the pressure of the liquid rubber injected between the core shaft 1 and the sleeve 3. A through hole 10 whose opening and closing is finely adjusted by a valve 9 is provided. The pressure regulating valve 9 is pressed by a through-hole 10 of the upper mold 6 by an O-ring of an elastic body attached to a projection 11 projecting in the opposite direction provided on the upper mold 6, and the pressure regulating valve 9 is disposed between the sleeve 3 and the core shaft 1. The pressure of expansion during vulcanization when liquid rubber is injected into the rubber is adjusted by the elastic force of the O-ring 12. Further, the upper mold 6 and the lower mold 7 are fixed by a spring 13.

[0006] However, such a roller manufacturing die has a large number of parts, requires complicated assembly and requires a long time, has a low manufacturing efficiency, and sometimes the pressure regulating valve is displaced from a predetermined position. Also, the O-ring is made of rubber, the elastic force is weakened by heating at the time of vulcanization, it cannot maintain a stable internal pressure, and it is liable to be deteriorated by repeated use, and has to be replaced frequently. .

[0007] In order to solve the above drawbacks, the present invention is simple to assemble, has good production efficiency, maintains a constant internal pressure even when the pressure regulating valve is pressed and heated properly, and has a long life and a high yield. It is an object of the present invention to provide a roller manufacturing apparatus with good performance.

[0008]

To achieve the above object, a roller manufacturing apparatus according to the present invention comprises: a cylindrical mold in which a sleeve surrounding a core axis is coaxially inserted along an inner wall; An upper mold and a lower mold inserted into a cylindrical mold while sandwiching the ends of the sleeve bent to the outer wall of the sleeve, an injection device for injecting an elastic material between the core shaft and the sleeve, a core shaft and the sleeve A pressure adjusting valve that adjusts the pressure between the upper mold and the upper mold, a spring that applies a desired pressure to the pressure adjusting valve,
A fixed frame to which the pressure adjusting valve is slidably fixed via a spring, wherein the fixed frame is assembled integrally with the pressure adjusting valve, and is detachably engaged with a projection projecting from the upper mold. Things.

[0009]

In the roller manufacturing apparatus, the pressure adjusting valves for opening and closing the through holes formed in the upper mold to adjust the pressure in the gap between the core shaft and the cylindrical mold project in the upper mold in opposite directions. And is slidably fixed via a spring to a fixing frame engaged with the projection. The pressure adjusting valve, the spring, and the fixed frame are integrally assembled, and the mold can be easily set only by engaging the pressure adjusting valve, the spring, and the projection of the upper mold. Also, since the pressure regulating valve is incorporated in the fixed frame in advance, unlike the conventional elastic body using the O-ring, the O-ring comes off from the pressure regulating valve and the load is not applied to the pressure regulating valve. I won't. for that reason,
Defective products are not manufactured, and the yield can be improved.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a roller manufacturing apparatus according to an embodiment of the present invention;

A roller manufacturing apparatus S shown in FIG. 1 is provided with a cylindrical mold 14 in which a sleeve 3 made of a fluororesin (hereinafter referred to as PFA) tube is attached to an inner wall.
A stop 15 is provided for fixing the end of the sleeve 3 folded back to the outer wall 4. The stopper 15 is formed of an elastic body fastening member having a larger friction coefficient between the sleeve and the stopper 15 than the friction coefficient between the cylindrical mold 14 and the sleeve 3. Conical caps 16a and 16b are provided at the upper and lower ends of the core shaft 1 which is coaxially installed at the center of the cylindrical mold 14, and an upper mold 17 and a lower mold 18 for fitting the caps 16a and 16b respectively. Is fitted into the cylindrical mold 14. The lower mold 18 has a tapered portion 2 fitted to an injection port 20 of a liquid rubber 19 which is an elastic material connected to an injection device (not shown).
One. The upper mold 17 is provided with a through hole 23 which is finely adjusted by a pressure adjusting valve 22 and opens and closes.
During injection or vulcanization, a pressure exceeding a certain pressure is applied to the cylindrical mold 14.
When a load is applied from the inside, the pressure fine adjustment valve 22 is opened, and the internal pressure is adjusted. In addition, the cylindrical mold 14
The liquid rubber 19 is removed, and a small hole 24 is provided in the vicinity of the boundary surface with the bottom surface of the upper mold 17, so that the air interposed in the gap between the cylindrical mold 14 and the sleeve 3 can be released when the liquid rubber 19 is injected. . Further, the upper mold 17 and the lower mold 18 each have a projection 25 projecting in the opposite direction, and can be pressurized by the spring 26 hooked on the projection 25 in accordance with the expansion of the liquid rubber 19.

As shown in FIG. 2, the pressure adjusting valve 22 of the roller manufacturing apparatus S having such a configuration is slidable by a fixing member 29 attached to a hole 28 formed in a fixing frame 27. Supported. A spring 31 is interposed between the projection 30 of the pressure regulating valve 22 and the fixed frame 27, and the pressure regulating valve 22
Is pressed into the through hole 23 of the upper mold 17. The pressure regulating valve 22, the fixed frame 27, the spring 31, and the fixed member 29 are integrally assembled, and the groove 32 provided in the fixed frame 27 is provided with the protrusion 25 of the upper mold 17 as shown in FIG.
Is engaged.

A method of manufacturing a roller using the manufacturing apparatus S having the above configuration will be described.

A PFA tube 3 having a diameter of 95 to 98% of the inner diameter of the cylindrical mold 14 and having an etched inner surface is attached to the inner wall of the cylindrical mold 14, and the folded end is a stopper 1.
Fix at 5. A primer for promoting adhesion to the liquid rubber is applied to the inner surface of the PFA tube 3. Thereafter, the core shaft 1 on which a primer is applied and the caps 16a and 16b are fitted is inserted, and the upper mold 17 and the lower mold 18 are fitted to fix the core shaft 1. Then, the fixed frame 27 in which the pressure adjustment valve 22 is set is engaged with the projection 25 of the upper mold 17, and after the pressure adjustment valve 22 is pressed into the through hole 23 of the upper mold 17,
A spring 26 is hooked and fastened to the projection 25 of the upper mold 17 and the lower mold 18. When the injection port 20 of the injection device for the liquid rubber 19 is inserted into the lower mold 18, the core shaft 1 is pushed upward together with the cap 16b, and the lower mold 18 and the cap 1 are moved upward.
6b, the liquid rubber 19 is formed between the core shaft 1 and the P.
It is injected between the FA tubes 3. The liquid rubber 19 is a low-viscosity type (100 to 2000 cp), but is injected under a pressure such that the liquid rubber injection pressure> the pressure resistance of the pressure control valve, and is interposed between the cylindrical mold 2 and the PFA tube 3. Air is released from the small holes 24 and the liquid rubber 19 is PF
The A tube 2 is stretched until it comes into close contact with the cylindrical mold 14.
When the liquid rubber 19 is further injected, the liquid rubber 19 is
Presses the pressure regulating valve 22 through the gap between the cap 16a and the upper mold 17, and when the spring 31 becomes larger than the load pressing the pressure regulating valve 22, the pressure regulating valve 22 is opened, and the liquid rubber 19 is removed from the through hole 23. Gushing. At this time, the injection of the liquid rubber 19 is stopped, and the roller manufacturing apparatus S is left in a thermostat to cure and cure the liquid rubber 19. At this time, the liquid rubber 19 expands, and when the pressure regulating valve 22 is pressed at a certain pressure or more, the pressure regulating valve 22 opens and releases excess rubber. After vulcanization and curing, it is cooled to obtain a roller.

The above description is an embodiment applied to the production of a pressure roller of an electronic copying machine. The apparatus for producing a roller according to the present invention is not limited to this, but can be applied to other rollers.

[0016]

As is apparent from the above description, according to the roller manufacturing apparatus of the present invention, the pressure adjusting valve for adjusting the pressure in the gap into which the elastic material is injected can be assembled integrally with the fixed frame. Thus, the manufacturing apparatus can be easily set, and the manufacturing efficiency can be improved. In addition, since the pressure regulating valve is reliably pressed, it can be manufactured with good yield without manufacturing defective products.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of a roller manufacturing apparatus according to the present invention.

FIG. 2 is a side view showing a main part of the embodiment shown in FIG. 1;

FIG. 3 is a side view showing a main part of the embodiment shown in FIG. 1;

FIG. 4 is a configuration diagram showing a conventional example.

[Explanation of symbols]

 1 ... core shaft 3 ... sleeve 14 ... cylindrical mold 17 ... upper mold 18 ... lower mold 19 ... ... Liquid rubber 22 ... Pressure regulating valve 25 ... Projection 26 ... Spring 27 ... ... Fixed frame S ... Roller manufacturing device

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Narita Kusaka 2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture Inside Showa Electric Wire & Cable Co., Ltd. 2-1, 1-1 Sakae Oda-ku, Showa Electric Wire & Cable Co., Ltd. (72) Inventor Keiji Sato 2-1-1, Odaei, Kawasaki-ku, Kawasaki, Kanagawa Prefecture Showa Electric Wire & Cable Co., Ltd. 2-1, 1-1 Oda Sakae, Kawasaki-ku, Kawasaki-ku, Kanagawa Prefecture Inside Showa Electric Wire & Cable Co., Ltd. (56) References JP-A-2-171224 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B29D 31/00 B29C 69/00 G03G 15/20

Claims (1)

(57) [Claims] 1. A cylindrical mold inserted coaxially around a core axis along an inner wall, and an end of the sleeve bent up to an outer wall of the cylindrical mold. An upper mold and a lower mold that are inserted into a mold, an injection device that injects an elastic material between the core shaft and the sleeve, and a pressure adjustment valve that adjusts a pressure between the core shaft and the sleeve. the upper mold, possess a spring for loading the desired pressure to the pressure regulating valve, and a fixed frame in which the pressure regulating valve through the spring is slidably secured, said fixed
The frame is assembled integrally with the pressure regulating valve, and
An apparatus for manufacturing a roller, which is detachably engaged with a projection protruding from a mold .