JPH02103582A - Manufacture of pressure roller for fixing device - Google Patents

Abstract

PURPOSE:To improve precision of pressure roller by working a core bar into a shape almost reverse of the outline of the roller, molding rubber in a proper thickness around a periphery thereof and polishing and grinding it, and finishing the roller through utilizing a relief in the working and restoring force after the working of the rubber part. CONSTITUTION:The round bar shaped core bar 1 of the pressure roller is cut into a covergent-divergent shape with both edges chamfered. The rubber 2 is molded in the proper thickness around the periphery of the core bar 1, and the surface of this rubber 2 is polished or grinded in an axial direction into straight or a concave shape by a polishing or grinding tool 3. By utilizing relief in the direction of the core bar 1 due to the difference of thickness at the time of working by grinding or cutting, a thick part is cut by comparatively little and a thin part is cut by comperatively large. Thus, without changing the direction of tool 3 when the rubber 2 is polished or grinded, the precision of the pressure roller is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a pressure roller used in a heat roller type fixing device.

[Conventional technology]

Conventionally, in a human roller type fixing device that handles large size paper such as A1 to AO, it is widely known that the influence of heat from a heat roller or the like on a pressure roller has a large effect on fixing performance. In some of such fixing devices, in order to correct the influence of heat, the shape of the pressure roller is such that the shaft is thick at the center and narrow at both ends in a 7-shape shape.

The method for manufacturing this pressure roller is usually to mold rubber 2 to an appropriate thickness around the outer periphery of a round bar-shaped core metal 1 shown in FIG. A method has been adopted in which a polishing or grinding tool 3 is used to polish or grind the shaft from the end to the center in a figure 7 shape to obtain the target shape as shown in FIG.

[Problem to be solved by the invention]

However, according to the above manufacturing method, it is necessary to change the direction of the polishing or grinding tool 3 when transitioning from the step shown in FIG. 6 to the step shown in FIG. 7, which increases the number of steps and There is a problem in that the accuracy of the pressure roller is often reduced when changing the direction of the polishing or grinding tool 3.

The present invention was made to solve these problems, and the surface of the rubber molded around the outer periphery of the core metal is simply polished or ground in the axial direction into a straight or cone-shaped shape using a polishing or grinding tool. It is an object of the present invention to provide a method for manufacturing a pressure roller of a fixing device, which allows the outer diameter to be finished into a target shape with just one step.

[Means and effects for solving the problem] The present invention provides a heat roller type fixing device in which the core metal of the pressure roller is processed into a shape that is almost the opposite of the outer shape of the roller, and rubber is coated on the outer periphery to an appropriate thickness. At the same time, the surface of this rubber is polished or ground into a straight or cone cape shape in the axial direction using a polishing or grinding tool, and the relief during processing of this rubber part and the original strength after processing are utilized. , whose outer periphery is finished into the target shape.

With the above method, the polishing or grinding work of the rubber can be completed in one step, and the accuracy of the pressure roller is improved accordingly.

〔Example〕

The present invention will be described in detail below based on embodiments shown in the drawings.

As shown in FIG. 1, a core metal 1 provided in the shape of a round bar is cut to form a medium-thin shape with both ends chamfered as shown in FIG.

Next, as shown in FIG. 3, a rubber 2
Mold to the appropriate thickness. The surface of the rubber 2 is polished or ground into a straight or conical shape in the axial direction using a polishing or grinding tool 3, as shown in FIG.

Taking advantage of the escape in the direction of the core metal 1 due to the difference in the thickness of the rubber 2 during polishing or cutting, the cutting in thicker areas is relatively small, and the cutting in thinner areas is large. Do it like this.

By this polishing or grinding process, the diameter of the thick part of the rubber 2 becomes thicker by protruding outward from the processing line due to its restoring force, and the diameter of the thin part of the rubber 2 becomes thinner. do.

As a result, the external shape of the pressure roller is
As shown in FIG. 4, the ideal shape is thick at the center and thin at both ends.

〔Effect of the invention〕

As explained above, according to the present invention, by simply polishing or grinding the rubber 2 molded on the outer periphery of the core bar 1 in the axial direction into a straight or cone-shaped shape, the outer shape of the pressure roller can be changed to be thicker at the center and thicker at both ends. Since the part can be formed into an ideal shape that is thin like a single character, the number of steps can be reduced and costs can be reduced. Further, since the polishing or grinding process of the rubber 2 does not require changing the direction of the tool 3, the accuracy of the pressure roller can be improved.

[Brief explanation of drawings]

Fig. 1 is a front view of the core metal of the pressure roller of the present invention before cutting, Fig. 2 is a front view of the core metal of the present invention after cutting, and Fig. 3 is a malt on the core metal of Fig. 2. Fig. 4 is a partially cutaway front view of the pressure roller showing the state of polishing or grinding the rubber, Fig. 4 is a partially cutaway front view of the finished pressure roller of the present invention, and Fig. 5 is a conventional molded core metal with rubber. A partially cutaway front view of the pressure roller before polishing or grinding, Figures 6 and 7 are partially cutaway front views of the pressure roller showing the conventional rubber part polishing or grinding order, and Figure 4 is a conventional FIG. 2 is a partially cutaway front view of a finished pressure roller. 1...Core metal, 2...Rubber, 3...Abrasive or grinding tool. Figure Figure ``'-2 Figure Figure Procedure Amendment (Method) % Formula % 2 Name of Invention Method of Manufacturing Pressure Roller of Fixing Device Fuji Name Fuji Xerox Co., Ltd. Representative Director Kobayashi Taro Yota Kobayashi 4 Agent Address 2274 Hongo, Ebina City, Kanagawa Prefecture, 243-04 Contents of the Amendment Corrected to “Figure 8”

Claims (1)

[Claims] In a heat roller type fixing device, the shape of the core of the pressure roller is almost the opposite of the shape of the roller, and the outer periphery of the core is molded with rubber to an appropriate thickness, and the surface of this rubber is A fixing device characterized by polishing or grinding in a straight or cone-gave shape in the axial direction and finishing the outer periphery in a target shape by using the relief of the rubber during this processing and the restoring force of the rubber after processing. Method of manufacturing pressure rollers.