JPH0311607B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application of the Invention The present invention relates to a method for manufacturing a sleeved roll whose outer circumferential surface is coated with a sleeve made of fluororesin or the like for use as a fixing pressure roll of an electronic recording device. It is related to.

"Prior Art" Rolls in which the outer periphery of a cored rubber roll is coated with a fluororesin sleeve in order to improve mold releasability are known as pressure rolls for fixing in electrophotographic copying machines and the like.

Conventionally, this sleeved roll is produced by fixing both ends of a sleeve with an outer diameter smaller than the inner diameter of the cylinder, which is loaded inside the inner peripheral surface of the cylinder, to a side die that holds the core metal, and in this state, the core metal and sleeve A manufacturing method is adopted in which a rubber material is injected and filled into the annular space between the cylinders under high pressure, and the sleeve is expanded by the filling pressure and brought into close contact with the inner peripheral surface of the cylindrical shape, and the sleeve is integrated with the rubber material. ing.

``Problems to be Solved by the Invention'' However, in such conventional manufacturing methods, the sleeve is expanded toward the inner surface of the cylindrical shape by the filling pressure of the rubber material. The filling pressure becomes weaker than the expansion stress of the sleeve, causing a defect in which it does not expand sufficiently toward the inner circumferential surface of the cylindrical mold, resulting in poor air release between the inner circumferential surface of the cylindrical mold and the sleeve, resulting in defective shapes and dimensions of the product. There were some drawbacks that occurred.

Additionally, if a sleeve with a wall thickness of 0.1 mm or less is used, the tensile stress of the sleeve will overcome the viscous resistance of the rubber, causing wrinkles and waves due to partial elongation.
There was also the drawback that the sleeve could break.

"Technical means for solving the problems" In order to solve the above-mentioned conventional problems, this invention
After the air between the inner peripheral surface of the cylindrical shape and the sleeve loaded inside the cylinder is vacuum-sucked to bring the sleeve into close contact with the inner peripheral surface of the cylindrical shape, a rubber material is filled between the sleeve and the core metal. This ensures that the sleeve is in close contact with the inner surface of the cylindrical mold before filling with the rubber material, and eliminates defects such as molding defects, wrinkles, and waves in the sleeve, which are caused by expansion of the sleeve due to the filling pressure of the conventional rubber material. The present invention proposes a method for manufacturing a sleeved roll that makes it possible to reliably obtain a product molded to the desired shape and dimensions.

``Embodiment'' Below, an embodiment of the present invention shown in the drawings will be described. As shown in FIG. A circular holder 4,
4' is removably fitted into the circular holders 4, 4', and the shafts 6 at both ends of the core bar 5 are removably held in the center of the circular holders 4, 4'. In between, both ends of a sleeve 7 made of fluororesin or the like and having an outer diameter smaller than the inner diameter of the cylindrical mold 1 are clamped and fixed in an airtight manner.

The mold in which the core metal 5 and the sleeve 7 are held and fixed in the center of the side molds 2 and 2' in this way is attached to the side molds 2 and 2'.
At this point, it is connected and fixed to the tip of the injection pot 8.

The cylindrical mold 1 or the side mold 2' has an intake hole 1 that communicates with the annular gap 9 between the inner peripheral surface of the cylindrical mold 1 and the sleeve 7.
A vacuum pump 13 is connected to a joint nozzle 11 provided on the atmosphere side through a pipe 12. By driving this vacuum pump 13, the air in the gap 9 is removed from the intake hole 10. Vacuum suction is applied until the gauge pressure reaches 400 to 500 mmHg or more, and as a result, the sleeve 7
is expanded and brought into close contact with the inner peripheral surface of the cylindrical mold 1.

In this state, the rubber material 14 that has been filled in the injection pot 8 in advance is pressed by the plunger 15 and injected into the space between the core bar 5 and the sleeve 7 through the injection port 16 provided in the circular holder 4 of the side mold 2. do.

When filling is completed, the rubber material 14 begins to be discharged from the discharge port 17 provided in the circular holder 4' of the side mold 2', so the extrusion of the plunger 15 is stopped, the mold is removed from the injection pot 8, and its internal pressure is Immediately seal the inlet 16 and outlet 17 with a cap or the like so that the amount of water does not decrease.

Next, this mold is heated by a heating means,
After the internal rubber material is vulcanized and cured, the side molds 2, 2' and the circular holders 4, 4' are removed and the molded roll is taken out from the cylindrical mold 1.

Note that the rubber burrs protruding from both ends of the formed roll and the ends of the sleeve 7 are cut off.

"Effects of the Invention" As described above, according to the present invention, after the air between the cylindrical inner peripheral surface and the sleeve loaded inside the cylinder is vacuum-sucked to bring the sleeve into close contact with the cylindrical inner peripheral surface, Since the rubber material is filled between the sleeve and the core metal, the sleeve can be completely and reliably expanded and brought into close contact with the inner surface of the cylindrical shape before being filled with the rubber material, and as a result, even when filling with the rubber material, The sleeve is strongly held in close contact with the cylindrical inner circumferential surface by frictional force, and the roll with sleeve is formed into the desired shape and dimensions without causing defects such as wrinkles or waves due to partial elongation. It becomes possible to obtain.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a state in which a core metal and a sleeve are set in a mold, and FIG. 2 is a longitudinal sectional view showing a state in which a rubber material is injected into a mold. 1...Cylindrical type, 2,2'...Side type, 4,4'...
Holder, 5... Core metal, 7... Sleeve, 9...
Annular void, 14...Rubber material.

Claims (1)

[Claims] 1 After vacuum suctioning the air between the inner peripheral surface of the cylindrical shape holding the metal core in the center and the sleeve loaded inside the inner peripheral surface of the cylindrical shape to bring the sleeve into close contact with the inner peripheral surface of the cylindrical shape, the rubber material is A method for manufacturing a sleeved roll, characterized by filling between a sleeve and a core metal.