JPH04357022A - Production equipment of roller - Google Patents

Abstract

PURPOSE:To manufacture a roller, the production efficiency and yield of which are high. CONSTITUTION:A pressure regulating valve 22, which presses the through hole 23 of an upper mold 17 fitted to the upper part of a tubular mold 14 having a sleeve 3 attached on its inner wall, is slidably integrally set through a spring 31 to a fixed frame 27 having grooves, with which the projections 25 of the upper mold 17 engage. Accordingly, since no numerous assembling of minor parts is necessary, the setting of production equipment is performed easily in a short time and higher working efficiency can be realized. Further, since the pressure regulating valve is set in advance to the fixed frame so as to correctly press the through hole, liquid rubber is loaded under normal pressure, resulting in manufacturing no defective article.

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 its outer periphery, and more particularly to rollers for electronic copying machines, laser printers, and the like.

0002

[Prior Art] In recent years, the heat rollers used in the heat fixing units of electronic copying machines, laser printers, etc. have been required to have stable paper passing properties due to the demand for faster speeds, higher image quality, and automatic duplexing of these devices. It has become a problem. As rollers that meet these demands, multilayer structure fixing rollers, pressure rollers, etc. are being used that have a fluororesin layer on the surface that has good releasability from toner made of polyethylene or acrylic acid polymers with carbon black added. Became. Among these rollers, pressure rollers were made by vulcanizing and adhering silicone rubber to a metal core, grinding the surface, coating the outermost layer with a mixed latex of fluororubber and fluororesin through a primer, and baking it. In many cases, foreign matter that adheres or gets mixed in during the manufacturing process is carbonized during the firing process, resulting in protrusions or depressions on the roller surface or pinballs in the surface film.

For this reason, a sleeve of fluororesin tube with a diameter slightly smaller than the inner diameter is inserted inside the cylindrical mold, liquid rubber is press-fitted between the cores, and the sleeve is expanded.
Method of integral molding by firing and vulcanizing the entire mold
7097, Japanese Patent Publication No. 51-27276) are known.

0004

[Problems to be Solved by the Invention] However, it is difficult to fix a sleeve whose diameter is smaller than the inner diameter of the cylindrical mold, and furthermore, when injecting liquid rubber with low viscosity between the core shaft and the sleeve, it is difficult to fix the sleeve and the cylinder. Liquid rubber often flowed between the molds, reducing work efficiency.

Therefore, 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 by a pressing member 4, which is folded back to the outer wall of the cylindrical mold 2. There was a mold that was provided with an upper mold 6 and a lower mold 7 that were fitted into the upper and lower ends of the core shaft 1 and were fitted into the cylindrical mold 2, respectively. The lower mold 7 has an injection port 8 connected to a liquid rubber supply device (not shown), and the upper mold 6 has a core shaft 1.
and a through hole 10 whose opening and closing are finely adjusted by a pressure regulating valve 9 which regulates the pressure of liquid rubber injected between the sleeve 3 and the sleeve 3. The pressure regulating valve 9 is pressed into the through hole 10 of the upper mold 6 by an elastic O-ring attached to a protrusion 11 provided in the upper mold 6 and protruding in the opposite direction, and the pressure regulating valve 9 is pressed against the through hole 10 of the upper mold 6, and the sleeve 3 and the core shaft 1
The elastic force of the O-ring 12 adjusts the expansion pressure during vulcanization when the liquid rubber is injected between the two. Furthermore, the upper mold 6 and the lower mold 7 are fixed by springs 13.

[0006] However, such molds for manufacturing rollers have a large number of parts, making assembly complicated and time-consuming, resulting in poor manufacturing efficiency, and in some cases, the pressure regulating valve may come off from a predetermined position. In addition, the O-ring is made of rubber, and its elasticity weakens due to the heating during vulcanization, making it unable to maintain stable internal pressure.Furthermore, it easily deteriorates with repeated use, requiring frequent replacement. .

In order to solve the above-mentioned drawbacks, the present invention is easy to assemble, has good manufacturing efficiency, presses the pressure regulating valve correctly, maintains a constant internal pressure even when heated, has a long life, and has a low yield. The purpose of the present invention is to provide a roller manufacturing device with good quality.

[0008]

[Means for Solving the Problems] In order to achieve the above object, the roller manufacturing apparatus of the present invention includes a cylindrical mold into which a sleeve coaxially surrounding a core shaft is inserted along an inner wall thereof, and a cylindrical mold having a sleeve coaxially surrounding the core shaft. an upper mold and a lower mold that are inserted into the cylindrical mold while holding an end of the sleeve bent to the outer wall of the mold;
The upper mold includes an injection device for injecting an elastic material between the core shaft and the sleeve, and a pressure regulating valve for regulating the pressure between the core shaft and the sleeve, and the upper mold is configured to apply a desired pressure to the pressure regulating valve. The pressure regulating valve has a spring for loading and a fixed frame to which the pressure regulating valve is slidably fixed via the spring.

[0009]

[Operation] The pressure regulating valve, which opens and closes the through hole drilled in the upper mold to adjust the pressure in the gap between the core shaft and the cylindrical mold, is engaged with protrusions that protrude in opposite directions from the upper mold. It is slidably fixed to a fixed frame via a spring. The pressure regulating valve, spring, and fixing frame are assembled in one piece, and the mold can be easily set by simply engaging the valve with the protrusion of the upper mold, making work extremely efficient. In addition, since the pressure regulating valve is pre-assembled into the fixed frame, unlike conventional systems that use an elastic O-ring, the O-ring comes off from the pressure regulating valve and no load is applied to the pressure regulating valve. There is no need to worry. Therefore, defective products are not manufactured and yield can be improved.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment to which the roller manufacturing apparatus of the present invention is applied will be described with reference to the drawings. The 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 the inner wall, and the sleeve 3 is folded back to the outer wall of the cylindrical mold 14. A stopper 15 is provided for fixing the end of the holder. The stopper 15 is made of an elastic tightening member in which the coefficient of friction between the sleeve and the stopper 15 is greater than that 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 coaxially installed in the center of the cylindrical mold 14, and an upper mold 17 and a lower mold 18 into which the caps 16a and 16b are fitted, respectively. is fitted into the cylindrical mold 14. The lower mold 18 has a tapered portion 21 that fits into an injection port 20 for liquid rubber 19, which is an elastic material, connected to an injection device (not shown). The upper mold 17 is provided with a through hole 23 that opens and closes with fine adjustment by a pressure regulating valve 22, so that a pressure higher than a certain pressure is applied from inside the cylindrical mold 14 during injection of the liquid rubber 19 or during vulcanization. Then, the pressure fine adjustment valve 22 opens and the internal pressure is adjusted. In addition, the liquid rubber 19 portion of the cylindrical mold 14 is removed, and a small hole 24 is provided near the interface with the bottom surface of the upper mold 17 to fill the gap between the cylindrical mold 14 and the sleeve 3 when the liquid rubber 19 is injected. Intervening air can be released. Further, the upper mold 17 and the lower mold 18 are each provided with projections 25 projecting in opposite directions, and can be pressurized according to the expansion of the liquid rubber 19 by a spring 26 hooked on the projections 25.

As shown in FIG. 2, the pressure regulating valve 22 of the roller manufacturing apparatus S having such a structure is made 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 protrusion 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 as shown in FIG. Ru.

A method of manufacturing a roller using the manufacturing apparatus S configured as above will be explained. A PFA tube 3 having a diameter of 95 to 98% of the inner diameter of the cylindrical mold 14 and etched on the inner surface is attached to the inner wall of the cylindrical mold 14, and the folded end thereof is fixed with a stopper 15. A primer that promotes adhesion with liquid rubber is applied to the inner surface of the PFA tube 3. A primer is then applied to the caps 16a and 1.
After inserting the core shaft 1 into which the core 6b is fitted, the upper mold 17 and the lower mold 18 are fitted to fix the core shaft 1. And upper mold 1
Fixed frame 27 with pressure regulating valve 22 set on protrusion 25 of 7
the pressure regulating valve 22 into the through hole 23 of the upper mold 17.
After pressing, the springs 26 are hooked onto the protrusions 25 of the upper mold 17 and the lower mold 18 to fasten them. When the injection port 20 of the injection device for 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 1
8 and the cap 16b through the gap formed between the liquid rubber 1 and the cap 16b.
9 is injected between the core shaft 1 and the PFA tube 3. Although the liquid rubber 19 is a low viscosity type (100 to 2000 c.p.), it is injected under pressure such that the liquid rubber injection pressure exceeds the pressure resistance of the pressure regulating valve.
The air interposed between them is released from the small holes 24, and the liquid rubber 19 stretches the PFA tube 2 until it comes into close contact with the cylindrical mold 14. When the liquid rubber 19 is further injected, the liquid rubber 19 passes through the gap between the cap 16a of the shaft 1 and the upper mold 17 and presses the pressure regulating valve 22, and when the load of the spring 31 becomes greater than the load pressing the pressure regulating valve 22, the pressure increases. The regulating valve 22 opens and the liquid rubber 19 is ejected from the through hole 23. At this time, the injection of the liquid rubber 19 is stopped, and the roller manufacturing apparatus S is left in a constant temperature bath to vulcanize and harden the liquid rubber 19. At this time, the liquid rubber 19 expands, and when the pressure regulating valve 22 is pressed above a certain pressure, the pressure regulating valve 22 opens and releases the excess rubber. After vulcanization and hardening, it is cooled to obtain a roller.

The above description is one embodiment applied to the manufacture of a pressure roller for an electronic copying machine, and the roller manufacturing apparatus of the present invention is not limited thereto and can be applied to other rollers.

[0014]

[Effects of the Invention] As is clear from the above description, according to the roller manufacturing apparatus of the present invention, the pressure regulating valve for regulating the pressure in the gap into which the elastic material is injected can be assembled integrally with the fixed frame. Therefore, manufacturing equipment can be easily set up and manufacturing efficiency can be improved. Furthermore, since the pressure regulating valve is reliably pressed, it is possible to manufacture the product at a high yield without producing defective products.

[Brief explanation of drawings]

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

[Fig. 2] A side view showing the main parts of the embodiment shown in Fig. 1.

[Figure 3
]A side view showing the main parts of the embodiment shown in FIG.

[Figure 4] Configuration diagram showing a conventional example

[Explanation of symbols]

1... Core axis 3...Sleeve 14... Cylindrical mold 17...Top mold 18...Lower mold 19...Liquid rubber 22...Pressure regulating valve 26 Spring 27...Fixed frame S...Roller manufacturing equipment

Claims (1)

[Claims] 1. A cylindrical mold into which a sleeve that coaxially surrounds a core shaft is inserted along the inner wall, and an end portion of the sleeve bent to the outer wall of the cylindrical mold is held between the cylindrical mold and the cylindrical mold. An upper mold and a lower mold that are fitted into the mold, an injection device that injects an elastic material between the core shaft and the sleeve, and a pressure adjustment valve that adjusts the pressure between the core shaft and the sleeve, A roller manufacturing apparatus, wherein the upper mold has a spring that applies a desired pressure to the pressure regulating valve, and a fixing frame to which the pressure regulating valve is slidably fixed via the spring.