JP2003028143A - Method of manufacturing hollow roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a hollow roller containing a heating element and used in a fixing mechanism of an electrophotographic device and the like, capable of solving problems on lowering the manufacturing efficiency and increasing the manufacturing cost caused by the increase of the depreciation of mold, as the hollow roller is thinned to meet demands for reducing the power consumption and shortening a warm-up time, and a journal part is also thinned, which impairs the mechanical strength, and needs the complex machining to secure the strength in machining and the strength of a mounting structure of a driving gear and a driving pulley sheave. SOLUTION: The lowering of the manufacturing efficiency can be prevented by thickening the journal part while satisfying the demands for thinning an intermediate part of the hollow roller, and simplifying the mounting structure with driving components similarly as a conventional roller. The necking forming is performed on both ends of a material tube over a length corresponding to a length of the journal part to reduce inner and outer diameters and to increase the thickness. An outer diameter of the necking part is a thickness obtained by adding two times of the thickness by the specification and a proper finishing allowance to the inner diameter of the intermediate part, and then the outer periphery is cut and ground by the finishing allowance to manufacture the straight hollow roller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a hollow roller used as a fixing roller or the like having a heating element incorporated therein in an electrophotographic apparatus or the like.

[0002]

2. Description of the Related Art A fixing roller used in an electrophotographic apparatus such as a copying machine, a facsimile machine or a printer has always been manufactured by cutting and grinding a tube material.
In recent years, the fixing roller has been gradually thinned in response to the need for reduction of power consumption and shortening of warming-up time. As a result, the thickness of the fixing roller is 0.5 mm or less for an iron-based material, and aluminum. 0.7 mm for system materials
The following is now required. As a result of this thinning, the mechanical strength of the journals at both ends that support the roller and transmit the rotational force is significantly reduced, the roundness is reduced during processing, and the drive gear or drive wheel mounting structure Problems such as processing difficulty and breakage have come to occur.

[0003]

Conventionally, as a method of coping with this, the outer peripheral finishing is performed by curling the end face of the journal portion, and at the same time, the mounting structure of the drive gear or the drive wheel is burring treatment reinforcement and pin hole. Has been reinforced with long holes. For this reason, a complicated and diversified manufacturing process is required, which has been a problem that needs to be solved such as an increase in cost.

[0004]

SUMMARY OF THE INVENTION The present invention provides a method of manufacturing a hollow roller used for a fixing roller or the like which fundamentally solves the above problems. The above-mentioned problem in manufacturing the hollow roller arises from an attempt to reduce the wall thickness of the hollow roller. The present invention, a portion corresponding to the journal portion of the hollow roller is subjected to a mouth-drawing process of a required length in advance, the inner and outer diameters are reduced to impart and secure a considerable wall thickness, and then the outer peripheral portion of the hollow roller is covered over the entire length. Machining such as cutting and grinding into a right cylindrical shape. In this case, the inner diameter of the intermediate portion is not processed at all, and the diameter is kept as it is.

As a result, in the hollow roller, the portions corresponding to the journal portions at both ends are thick and the middle portion is thin. Hollow rollers having different wall thickness characteristics can be manufactured from a single tube. This manufacturing method has a feature that it can be applied to all metals that can be drawn, cut, and ground.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The necking of a raw pipe is performed by press molding, rotational molding and swaging machine. According to the present invention, by these processes, both ends of the raw pipe are squeezed at the same time or one end is squeezed at both ends to produce an intermediate product in which both ends are thin and an intermediate part is thick. This intermediate product is turned and ground to form a hollow roll with a slate outer circumference. The outer diameter of the silicon tube after the orifice of the journal part is narrowed to the inside diameter of the middle part by 2
Doubled and the necessary finishing allowance added. In the present invention,
The inner diameter of the middle part of the hollow roller is not processed at all and remains the inner diameter of the raw pipe. Therefore, the outer diameter of the raw pipe is more than the value obtained by adding twice the specified wall pressure to the inner diameter and the necessary finishing allowance. Must be diameter. Since the defective deformed portion occurs at the pipe end, it is necessary to set the length of the raw pipe mouth narrowing portion to a length that is predicted to be cut off later. This length is determined by trial and error because it depends on a plurality of factors such as the material, the drawing ratio, and the diameter outside.

[0007]

EXAMPLES The examples described below are examples embodying the present invention and do not limit the technical scope of the present invention. 1A to 1C are diagrams showing the outline of the manufacturing procedure. First, as shown in FIG. 1 (a), a metal tube is cut into a length which allows for the required finishing allowance in the product dimensions, to form a hollow roller element tube. Next, as shown in FIG. 1B, the portions corresponding to the journal portions at both ends are subjected to a narrowing process to reduce both the inner and outer diameters. If the outer diameter after the mouth-drawing is larger than the inner diameter of the intermediate portion required to be thinned by at least twice the required thin thickness, it is possible to manufacture a hollow roller having a straight outer diameter shape. Also, the length of the portion to be drawn can be freely set based on the design specifications of the journal portion. Then, as shown in Fig. 1 (c), the outer circumference is cut to the final dimension required for the specifications as a hollow roller,
Grinding completes a hollow roll with a straight outer diameter. A practical hollow roller is used by processing a mounting structure for a drive gear or a drive wheel on a portion of the hollow roller according to the present invention corresponding to a journal.

[0008]

Since the hollow roller manufactured by the manufacturing method of the present invention has the necessary thickness and mechanical strength in the journal portions at both ends, it is not necessary to reinforce for processing, and the mounting structure of the drive gear can be processed. Since it can be performed in the same manner as the conventional thick hollow roller, it can be expected to reduce costs by reducing related parts, processing man-hours, mold investment, and improving manufacturing efficiency.

[0009]

[Brief description of drawings]

[Fig. 1] ▲ a ▼ is a vertical cross-sectional view of a blank tube.

[FIG. 1] ▲ b ▼ is a vertical cross-sectional view of the intermediate product after the raw pipe is drawn

[Fig. 1] ▲ c ▼ is a vertical cross-sectional view after finishing the intermediate product.

Claims (3)

[Claims] 1. A metal base tube is formed by subjecting both ends to a narrowing process and then cutting and grinding the entire circumference into a right cylindrical shape, and has both thick end portions and a thin intermediate portion therebetween. Hollow roller manufacturing method 2. The method for manufacturing a hollow roller according to claim 1, wherein the thickness of both ends is at least 1.5 times the thickness of the intermediate portion. 3. The outer diameter is formed by not processing the inner diameter portion of the middle portion of the raw pipe having a diameter equal to or larger than the diameter obtained by adding twice the specified wall thickness to the inner diameter of the middle portion. The method for manufacturing a hollow roller according to claim 1.