JP2007320217A - Manufacturing apparatus of high heat conductive rubber roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing apparatus of a high heat conductive rubber roller capable of producing the high heat conductive rubber roller making dispersion on surface hardness by making a separation of heat conductive fillers caused of pressure on injection of a rubber, small. <P>SOLUTION: The apparatus comprises a cylindrical mold 12 with an inside diameter same as or larger than a finished outer diameter of the high heat conductive rubber roller, a core axis 16 arranged coaxially in a cylindrical mold 12 provided with a space 14 for forming a rubber layer of the high heat conductive rubber roller, a rubber inlet 20 opening to an end face 18 and a space 14, a plug 22 on the side of a rubber inlet 20 engaged one end of the cylindrical mold 12 for holding one end of the core axis 16, an exhaust port 24 opened to the end face 18 and the space 14 and an exhaust side plug body 26 engaged one end of the cylindrical mold 12 and holding one end of the core axis 16. The rubber inlet 20 is formed by a plurality of circular long holes. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus for manufacturing a high thermal conductive rubber roller used as a fixing roller (including a pressure roller; the same applies hereinafter) of an electronic copying machine or a laser beam printer (LBP).

  In recent electronic devices such as an electronic copying machine and an LBP, energy saving measures are taken by shortening the warm-up time and speeding up the initial sheet passing when the power is turned on or when returning from the standby state. At that time, it is a problem to quickly raise the surface temperature of the fixing roller to a set value.

  In order to quickly raise the surface temperature to a set value in a fixing roller used in an electronic copying machine or LBP, it is preferable to use a high thermal conductive rubber for the roller elastic layer. As the high heat conductive rubber, for example, a silicone rubber blended with a heat conductive filler as a heat conductive additive is used.

  Conventionally, when manufacturing a high thermal conductive rubber roller, a manufacturing apparatus shown in FIG. 3 is used. That is, a cylindrical mold 30 and a plug body 34 that holds a core shaft 32 disposed coaxially in the cylindrical mold are provided, and a circular rubber injection hole 36 having a diameter of 1 to 3 mm is formed in the plug body 34. 4 to 16 pieces are provided. A rubber compounded with a heat conductive filler is poured from these circular rubber injection holes 36 to fill the space 38 between the cylindrical mold 30 and the core shaft 32 with the rubber.

It has been conventionally known that a fixing temperature can be set low, and as a result, a heat conductive filler is blended in the coating layer of the fixing roller in order to reduce power consumption and shorten the warm-up time (patent) Reference 1).
JP-A-9-237007

Here, the conventional technique shown in FIG. 3 has the following problems to be solved.
When the rubber compounded with the heat conductive filler is injected from each circular rubber injection hole 36 of the conventional manufacturing apparatus shown in FIG. 3, the diameter of the rubber injection hole 36 is small and the rubber injection hole 36 is finely separated. Therefore, the heat conductive filler having a high specific gravity is separated by the casting pressure, resulting in variations in rubber hardness (roller surface hardness). That is, since the high specific gravity filler is separated, a difference in the hardness of the roller surface occurs between the rubber injection hole side and the opposite side in the longitudinal direction of the roller. As a matter of course, this is not preferable as a rubber roller product.

  The present invention has been made paying attention to the above points, and is a high heat conductive rubber roller that can reduce the separation of the heat conductive filler due to the pressure during rubber casting and can produce a high heat conductive rubber roller with a small variation in surface hardness. An object is to provide a manufacturing apparatus.

In each embodiment of the present invention, the above-described problems are solved by the following configurations.
<Configuration 1>
A cylindrical mold having an inner diameter equal to or larger than the outer diameter of the roller finish, a core shaft disposed coaxially in the cylindrical mold to provide a space for forming a rubber layer of the roller, an end surface, and the space A rubber injection hole plug that fits into one end of the cylindrical mold and holds one end of the core shaft; an exhaust hole that opens to the end surface and the space; An exhaust-side plug that is fitted to the other end of the cylindrical mold and holds the other end of the core shaft, and the rubber injection hole is formed by a plurality of arc-shaped long holes. Conductive rubber roller manufacturing equipment.

  Since the rubber injection hole is formed by a plurality of arc-shaped elongated holes, separation of the high specific gravity filler, which is a heat conduction additive, can be suppressed, so that it is possible to manufacture a high heat conduction rubber roller with a small variation in product hardness. it can.

<Configuration 2>
The apparatus for manufacturing a high thermal conductivity rubber roller according to Configuration 1, wherein the plurality of arc-shaped elongated holes are arranged at regular intervals along an outer peripheral edge of the rubber injection side plug body. Rubber roller manufacturing equipment.

<Configuration 3>
The high heat conductive rubber roller manufacturing apparatus according to Configuration 1 or 2, wherein the rubber injection hole has an opening area of 7 to ²⁰ mm ² .

  Hereinafter, embodiments of the present invention will be described in detail for each example.

FIG. 1 is an explanatory diagram of a high thermal conductive rubber roller manufacturing apparatus (hereinafter referred to as the present apparatus) according to a first embodiment. 2A and 2B are views showing details of the apparatus, in which FIG. 2A is a side view and FIG. 2B is a longitudinal sectional view taken along line AA in FIG.
As shown in the figure, this apparatus includes a cylindrical mold 12, a core shaft 16, a rubber injection side plug body 22 having a rubber injection hole 20, and an exhaust side plug body 26 having an exhaust hole 24.

  The cylindrical mold 12 has an inner diameter that is the same as or larger than the roller finished outer diameter. Here, the cylindrical mold 12 has a roller finished outer diameter and a large inner diameter means that the inner diameter of the cylindrical mold 12 is exactly the same as the roller finished outer diameter or slightly larger than the roller finished outer diameter. I mean. The core shaft 16 is disposed coaxially in the cylindrical mold 12 and provides a space 14 for forming a rubber layer (not shown) of the roller. The rubber injection side plug body 22 is fitted to one end of the cylindrical mold 12 and holds one end of the core shaft 16. The exhaust side plug 26 is fitted to the other end of the cylindrical mold 12 and holds the other end of the core shaft 16.

The rubber injection hole 20 is formed by a plurality of arc-shaped long holes as shown in FIG. The plurality of arc-shaped long holes are arranged at regular intervals along the outer peripheral edge of the rubber injection side plug body 22. The opening area of the rubber injection hole 20, that is, the total area obtained by integrating the opening areas of all the long holes is desirably 7 to ²⁰ mm ² . Although not shown, each rubber injection hole 20 is connected to a nozzle of a rubber press-fitting mechanism.

  When a rubber compounded with a heat conductive filler is injected from the rubber injection hole 20 of the rubber injection side plug body 22, the space 14 is filled with rubber while air is discharged from the exhaust hole 24 of the exhaust side plug body 26 to the atmosphere. Is done. At the time of rubber injection, since the rubber injection hole 20 is a plurality of arc-shaped long holes and has a large opening area, separation of the high specific gravity heat conductive filler is suppressed, and a high heat conductive rubber roller with a small variation in surface hardness can be obtained.

  Next, the degree of reduction in the variation in surface hardness when a high thermal conductive rubber roller is manufactured using this apparatus will be described. That is, the variation in surface hardness when the high thermal conductive rubber roller was manufactured using the conventional manufacturing apparatus shown in FIG. 3 was 3 to 4 points. This means that there is a difference of 3 to 4 points with a 1 kgf load of the Asker C hardness tester. Further, when the high heat conductive rubber roller is manufactured using another conventional manufacturing apparatus (not shown) in which the rubber injection hole 36 shown in FIG. Similarly, it was 5 points. On the other hand, when a highly heat conductive rubber roller was manufactured using this apparatus, the variation in surface hardness was 1 to 2 points.

When manufacturing a high heat conductive rubber roller using this apparatus, it is more preferable to satisfy the following conditions (1) and (2).
(1) The injection pressure of rubber injected from the rubber injection hole 20 is 0.1 to 10 MPa.
(2) As the rubber injected from the rubber injection hole 20, an addition reaction type silicone rubber having a thermal conductivity of 0.4 to 1.5 W / m · K is used.

It is explanatory drawing of the manufacturing apparatus of the high heat conductive rubber roller of Example 1. FIG. It is a figure which shows the detail of the apparatus, (a) is a side view, (b) is a longitudinal cross-sectional view which follows the AA line of (a). It is a figure which shows the principal part of the manufacturing apparatus of the conventional high heat conductive rubber roller, (a) is a side view, (b) is a longitudinal cross-sectional view which follows the BB line of (a).

Explanation of symbols

12 cylindrical mold 14 space 16 core shaft 18 end face 20 rubber injection hole 22 rubber injection side plug body 24 exhaust hole 26 exhaust side plug body

Claims (3)

A cylindrical mold having an inner diameter equal to or larger than the roller finished outer diameter;
A core shaft disposed coaxially in the cylindrical mold to provide a space for forming a rubber layer of the roller;
A rubber injection side plug that has a rubber injection hole that opens in an end surface and the space, and is fitted to one end of the cylindrical mold to hold one end of the core shaft;
An exhaust hole that opens to the end surface and the space, and includes an exhaust side plug that is fitted to the other end of the cylindrical mold and holds the other end of the core shaft,
The apparatus for producing a high thermal conductive rubber roller, wherein the rubber injection hole is formed by a plurality of arc-shaped long holes. In the manufacturing apparatus of the high thermal conductivity rubber roller according to claim 1,
The apparatus for producing a high thermal conductive rubber roller, wherein the plurality of arc-shaped long holes are arranged at regular intervals along an outer peripheral edge of the rubber injection side plug body. In the manufacturing apparatus of the high heat conductive rubber roller according to claim 1 or 2,
The apparatus for manufacturing a high thermal conductive rubber roller, wherein an opening area of the rubber injection hole is 7 to ²⁰ mm ² .

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