JPS58156976A - Rubber roll for fixation - Google Patents

Abstract

PURPOSE:To prevent the generation of nonuniform revolution of a roll when recesses are formed on the surface of the roll and to obtain stable fixability by setting the shape of splitting lines obliquely with respect to the axial direction of the roll. CONSTITUTION:A pair of upper and lower dies 7 are set to have the different shapes between the mating faces 8 for shaft parts 3 and the mating faces 9 for roll parts 1. The faces 9 are set in the inclined relation with respect to the faces 8 so that the faces on one side are higher and the faces on the other are lower, and the faces 9 and 9 are set in the mutually opposite inclined relation. Partition lines 4 corresponding to the split parts 9a formed of the faces 9 and 9 are formed to a rubber roll 1. The lines 4 have the shape inclined with respect to the direction of the roll shafts 3 so that, even if recesses are produced by the generation of nonuniform swelling caused by difference in rubber density, the concentration of the recesses to one place toward the circumferential direction of the roll is obviated, and the large fluctuations in load in the revolution of the roll are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to rubber rollers used in Shigeko photocopiers, electronic printers, etc., for thermally fixing toner images formed on copy paper. 6. PRIOR ART This rubber fixing roller has a dividing line formed by a mold during vulcanization molding on its surface.

The conventional dividing line is a rubber roller (1) as shown in Figure 1.
) surface (21vc) This line (21vc) is formed as a groove (4) parallel to its roller axis (3) direction
4), for example, by using a pair of upper and lower molds (6), (6) whose mating surfaces (5), (5) are formed parallel to the roller axis direction, as shown in FIG. During vulcanization molding of the rubber roller (1), the small size formed at the mating surfaces (5), (5) is due to the difference in vulcanization pressure between the divided part (5a) and other parts of the mold (6). This is the difference in rubber density that occurs, which is a phenomenon peculiar to vulcanization molding using a mold and cannot be avoided. This dividing line (4) is usually called a perchage line.

Here, when using it as a fixing rubber roller of a silicone oil coating/applying type fixing device with a perchage line (4) formed on the rubber roller surface (2), the difference in rubber density as described above will directly affect the amount of oil swelling. This results in a so-called non-uniform swelling.

As shown in Fig. 3, a recess (2a) is formed on the rubber roller surface (2) corresponding to the perchage line (4).This recess (2a) causes the following problems.
That is, when this concave portion (2a) is located at the contact portion of the pair of fixing rubber rollers as shown in FIG. The fluctuations cause uneven rotation of the rollers. This non-uniform rotation not only adversely affects fixing performance, but also causes deterioration in image quality due to poor transfer, etc., especially in small copying machines where the conveyance distance between the transfer section and the fixing section is short.

In addition, to solve the above-mentioned problem, the diameter of the rubber roller becomes smaller if the perchage line (4) is swollen with silicone oil in advance and the rubber roller (1) is made to have a uniform diameter. In addition, during long-term use, perchage lines occur due to the difference in rubber density, resulting in the same drawbacks as described above.

OBJECT An object of the present invention is to provide a fixing rubber roller that does not cause the above-mentioned problems even if depressions are formed on the surface of the fixing rubber roller due to the formation of a tack line. As a result of various studies to achieve the above object, the present invention has developed a conventional perchage line shape which is parallel to the axial direction of the roller, as illustrated in (4) of Fig. 5'. It has been found that the above-mentioned problem can be solved and the object of the present invention can be achieved by setting the roller to be inclined with respect to the direction of the roller axis (3).

Example An embodiment of the present invention will be described below.

FIG. 6 is an example of a mold used for vulcanization molding the rubber roller according to the present invention.

As shown in the figure, the pair of upper and lower molds (7), (7) have mating surfaces (8), (8) of the shaft portion and mating surfaces (9), (9) of the roller portion.
) are set to different shapes, i.e. mating surfaces (8), (8)
&-1 As before, the mating surfaces (9), (9) Fi, mating surfaces (8),
(8), one side is set to be higher and the other is lower, and the mating surfaces (9) and (9) of each mold (7) are set in an incline relationship that is opposite to each other. As shown in FIG.
, (7), a version line (4) corresponding to the dividing portion (9a) formed by the inclined mating surfaces (9), (9) is formed. This perchage line (4) has an inclined shape with respect to the direction of the halo roller axis (3), so when it is used as a fixing rubber roller in a silicone oil coated fixing device, uneven swelling occurs due to the difference in rubber density. Even if a concave portion occurs, it is not concentrated in one place in the circumferential direction of the roller, so it does not cause large load fluctuations in the rotation of the roller.

It should be noted that the inclination angle of the perchage line (4) with respect to the axial direction of the rubber roller may be set as appropriate, and that the mold for vulcanization molding the fixing rubber roller according to the present invention is a two-part mold according to the above embodiment. Instead, the present invention can be achieved in the same way by dividing the roller into three or four parts in the radial direction with respect to the f-roller axis.

Effects As described above, the present invention provides a fixing rubber roller in which a dividing line (perchage line) is formed by a mold during vulcanization molding on the surface of the rubber row 2, in which the shape of the dividing line is inclined with respect to the axial direction of the roller. Since it is a fixed type, it can be used as a rubber roller for fixing in a silicone oil-coated fixing device.

However, it is possible to obtain stable fixing performance without causing the uneven rotation of the rollers as in the past, and even in small copying machines, there is no problem of image quality deterioration due to poor transfer due to stable conveyance. There are advantages.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a conventional fixing rubber roller, Figure 2 is a perspective view of its vulcanization mold, Figure 3 is a sectional view showing the swollen state of the rubber roller in Figure 1, and Figure 4 is a diagram showing the rubber roller in Figure 1. FIG. 5 is a structural diagram of the fixing rubber roller of the present invention, and FIG. 6 is a perspective view of its vulcanization mold Q. 1...Rubber roller 2...Rubber roller surface 3...
・Roller shaft 4...Dividing line (heart section line) 7...
・Mold 8...Mating surface of shaft portion 9...Mating surface of roller portion Applicant Minolta Camera Co., Ltd. Figure 1

Claims (1)

[Claims] 10. - In the rubber roller for fixing, a dividing line is formed on the surface of the rubber roller by a mold during vulcanization molding.
A fixing rubber roller, characterized in that the shape of the dividing line is inclined with respect to the axial direction of the roller.