JPH0626515A - Rolling element and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a cylindrical rolling element having an hourglass-shaped cross section in the longitudinal direction with high shape accuracy such as concentricity between an outer diameter and an inner diameter or straightness and circularity of the outer diameter, and a method for manufacturing the rolling element by use of a seam welded pipe. CONSTITUTION:A hollow cylindrical seam welded pipe 1' with both ends thereof cut is prepared. Tapered pushes 3 are press-fitted into both opening ends. The pipe 1' is formed into an hourglass shape in such a manner that the diameter thereof becomes larger from the center toward both ends.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling element which constitutes a substrate or an outer peripheral surface for an electrophotographic photoreceptor, a communication device, a sheet feeding / discharging, a fixing, etc. The present invention relates to a manufacturing method, and more particularly, to a rolling element having a uniform or almost uniform overall thickness and a drum shape, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Rolling elements such as sheet feeding / discharging and fixing rollers used in apparatuses such as copying machines, office machines, and communication devices are made of pipe material as a base material, and a hollow cylindrical roller body has rollers for both driving and driven bodies. There are known ones that rotate on the basis of the outer diameter of the main body, and those that rotate on the basis of the shaft center of the flange with a flange serving as the rotation reference fixed to the inner diameter.

By the way, in the rolling element roller used in the above-mentioned apparatus, for example, the paper feeding / discharging roller has a pair of upper and lower rollers to feed the paper. In this case, due to variations in the thickness of the paper to be fed, variations in the mounting position of the rollers, pressure conditions, etc., it is not possible to feed the paper at a certain position, such as in the center between the rollers, and deviation occurs or the paper is fed. Wrinkles may occur. Further, for example, the fixing roller is configured to pass a sheet having an unfixed toner image between it and the pressure roller, and apply heat and pressure to the sheet to fix the toner image, but the fixing roller has a heat source built-in. Therefore, the outer diameter is deformed due to the thermal expansion, and as in the case of the paper feeding / discharging roller, paper wrinkles may be generated.

In order not to cause such an inconvenience, it is general that one roller of the paper feeding / discharging roller and the fixing roller have an outer diameter of the central portion smaller than outer diameters of both end portions (a drum shape). Target. By doing so, the paper passing between the two rollers receives a force that spreads to both ends of the rollers, so that paper wrinkles and the like are prevented from occurring. But,
Such a rolling element roller has a continuous shape value and a surface roughness,
High shape accuracy such as outer diameter straightness and roundness is required to reduce rotational runout, and in the past, the surface of extruded aluminum metal pipes (including Al alloy pipes) was mirror-finished. Although it has been subjected to secondary processing such as cutting, it has drawbacks such as a very high manufacturing cost. In addition, most of the substrates obtained by such a conventional method have variations in wall thickness. The extruded pipe and the drawn pipe have uneven thickness of about ± 10% to ± 15% of the average wall thickness on the same circumference of the substrate, the coaxiality between the inner diameter and the outer diameter is not sufficient, and the I and I pipes have the same circle. Inconveniences such as uneven thickness on the circumference and unevenness in the longitudinal direction of the pipe material have been recognized. Furthermore, the fixing roller and the like that require heating have variations in heat conduction, which impede the rapid heating and cooling effects due to thinning.

As described above, the hourglass shape is usually formed by cutting. However, in the case of cutting, when a substrate is required to have a large pipe diameter and a thin wall shape, it is necessary to cut the work piece during cutting. Material distortion due to chucking of the material, deformation at the time of opening after cutting, swelling and chattering of the work surface during cutting of the bite easily occur, and there are problems of wear resistance and durability of the bite, especially large diameter -It is difficult to continuously obtain high-precision shape accuracy and fine surface roughness with a long thin substrate.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to cover a small diameter to a large diameter, and to have a high degree of accuracy such as concentricity formed by an outer diameter and an inner diameter, or straightness and roundness of the outer diameter. (EN) A rolling element roller having a cylindrical cross section in the shape of a zigzag and a method for manufacturing the same. Another object of the present invention is to provide a rolling element roller such as a fixing roller, which is thin and has a uniform thickness so that heat conduction during heating is evenly distributed, and rapid heating and cooling can be performed quickly, and its production. It provides a method. Still another object of the present invention is to provide a highly accurate rolling element roller for forming a pipe material inner diameter and outer diameter at the same time by plastic working without forming a zigzag shape by cutting the pipe material outer diameter, and a manufacturing method thereof. It is a thing. Still another object of the present invention is that continuous mass production is possible, tool durability is high, quality variation is small, man-hour reduction, cost reduction
(EN) A rolling element roller that can be downed and a method for manufacturing the same.

[0007]

The first aspect of the present invention is a rolling element such as a roller, which is formed by using a metal strip or a metal plate as a base material.
It is characterized in that a welded hollow cylindrical electric resistance welded pipe is formed into a drum shape with a large diameter from its central portion to both ends by plastic working.

A second aspect of the present invention is a method for manufacturing a rolling element such as a roller, which comprises rolling a metal strip or a metal plate and welding the joint portion by high frequency welding to produce an electric resistance welded pipe. The sewing pipe is further drawn and straightened, then both ends of this are cut, and punches with a taper are inserted from both open ends to form a large drum shape from the central part to both ends. I am trying.

The present inventor has conducted many studies and researches to achieve the above-mentioned object. As a result, an electric resistance welded pipe or a machined electric resistance welded pipe is used as a base material, and the cylindrical base body (tubular material) is properly treated from both ends. It was confirmed that a desired hourglass shape can be obtained for the outer diameter by simultaneously press-fitting a taper punch having a different Taber angle and expanding the inner diameter of the pipe material. The present invention is made by this.

FIG. 1 schematically shows a paper passing device in which a rolling element roller 1 (a drum-shaped roller) according to the present invention and a cylindrical roller 2 are combined. The drum-shaped roller 1 and the cylindrical roller are shown. It is close to the roller 2 at the end, but is far away at the center.

As an example of the shape accuracy of the hourglass-shaped roller 1, the outer diameter is 10 to 60 mm, the length is 300 mm or less, the wall thickness is 2.0 mm or less, and the hourglass shape value is 2.0 mm or less. Note that the "hourglass shape" referred herein, as seen in FIG. 5, a difference (D ₂ -D ₁₎ at the end outer diameter D ₂ and the central outer diameter D ₁ of the hourglass-shaped rollers It is a cylinder.

The present invention will be described in more detail below with reference to the accompanying drawings.

An electric resistance welded pipe or a processed electric resistance welded pipe is used for the base body (tubular material) before being formed into a drum shape, and the material thereof is aluminum, copper, stainless steel, nickel, iron or an alloy thereof, steel, Examples include iron and steel, and aluminum and aluminum alloys are particularly preferable.

FIG. 2 shows a process of manufacturing an electric resistance welded pipe 1b (which may be referred to as "pipe forming material" in the example of FIG. 2 for convenience) from the metal strip 1a. A plurality of rollers (forming roller) for the metal strip 1a at a speed of 1 to 100 m / min.
5 is rolled into a cylindrical shape and abutted, and the end portion (the abutted portion) is continuously welded by the high frequency welding machine 6, and depending on the specifications such as dimensional accuracy and surface property, the outer periphery of the welded portion and The inside of the pipe material 1b is cut and / or cut by the cutter 8 to a desired size.
Is built. Here, the pipe-forming material 1b is manufactured from the metal strip 1a, but it can be formed from a metal plate through similar steps.

FIG. 3 shows a pipe (pipe forming material) 1b produced in the process of FIG. 2 and the "cut" pipe producing material 1 in the example of FIG.
In order to improve the sizing and the shape accuracy, the drawing (FIG. 3 (a)) and the correction (FIG. 3 (b) may be used.
₁ ) (b ₂ ) is to be carried out. Cutting (Fig. 3
The item (c)) may be hereinafter referred to as "drawn material 1c" for convenience sake. In the figure, 9 is a plug, 9a is a rod, 10
Is a lubricant, 11 is a tongue, and 13 'is a die.

The electric-resistance welded pipes (pipe-making material 1b, drawn material 1c) of appropriate length obtained in the steps shown in FIGS. 2 and 3 have good welding quality without deformation of the electric-resistance welded portions. In particular, the pipe material 1c obtained by drawing and straightening in the process of FIG. 3 has a smooth cylindrical cross section. FIG. 4 is an outline of the pipe expanding process.

Both ends of the pipe material 1 '(pipe forming material 1b or drawn material 1c) cut to a required length are set on the same axis as the taper punch 3, and then the taper punch 3 is formed.
Is determined by the amount of stapling to be formed, and the taper angle is set in consideration of sprinks back during pipe expansion. Further, when expanding the pipe, the pipe is bent and the heat treatment hardness (HRc53 to 55) that can withstand the expanding pressure is imparted, and the surface roughness is such that seizure does not occur due to friction resistance during expanding, preferably Rmax 0.2 mm. It is finished below. In order to prevent seizure during pipe expansion, a low-viscosity lubricating oil with good releasability is used.

In the tube expanding step of FIG. 4, the steps (a), (b) and (c) proceed in this order, and at the same time as the tube expanding is completed, the end is molded and is removed from the punch 3 by the stopper 4. Next, by equalizing the surface roughness of the outer periphery of the tubular material formed in the hourglass shape and polishing with a thread buff for the purpose of removing appearance scratches,
A rolling element roller that is not cut can be obtained.

[0019]

EXAMPLES The present invention will be described more specifically by way of examples. However, the present invention is not limited to this.

Example 1 The electric resistance welded pipe (drawn material) 1c obtained in the process of FIG. 3 was used as a pipe material, and as shown in FIG. 4, the taper punches 3 were press-fitted from both ends of the pipe to change the inner diameter of the pipe material. Expand and further polish the outer peripheral surface to manufacture 20 rolling element rollers with a hourglass shape.
Three of them were randomly sampled. The conditions in that case are as follows.

I. Conditions for pipe expansion (1) Base material (tube material) Material Al-Mg alloy (5052H-24) Dimensions (outer diameter) 19.8 mm × (thickness) 0.6 mm × (length) 289 mm ( 2) Expansion method Die-less double-end expansion method Squeezing amount 0.12mm ± 0.05mm Punch taper 1 / 600mm Lubrication oil Polypten (NV, HV-15) (3) Mold (punch material) SKD -11, quenching hardness HRc 53 to 55 Surface roughness Rmax 0.2μm or less (4) Machine Horizontal double-headed hydraulic press (10 ton, manufactured by Ricoh)

II. Polishing conditions (a) Polishing machine Centerless polishing machine (manufactured by Nomizu Kikai Seisakusho Co., Ltd.) Rotation speed 1,360 rpm, Feed rate 0.75 m / min (b) Abrasive grindstone Thread buff / flap # 600 (Nippon Special Research Institute) (Made by Tosha)

III. Measuring Method (1) Outer Diameter The rolling element roller is equally divided in the longitudinal direction 17, and the maximum and minimum values of the respective diameters are measured. (2) Total runout Insert a perfect circular cylindrical body into both ends of the rolling element roller, support each of these cylindrical elements with two rotating rollers, and rotate the rolling element roller when the rotating roller is rotated. The maximum value of runout at 17 equal parts in the longitudinal direction. (3) Straightness The maximum value obtained by dividing the cylindrical outer peripheral surface of the rolling element roller into 4 equal parts and dividing them into 17 equal parts in the longitudinal direction, and measuring a total of 4 x 17 = 68 points. (4) Roundness The outer diameter of the rolling roller is divided into 17 equal parts in the longitudinal direction, and the maximum value of the outer diameter-the minimum value of the outer diameter / 2 at each point is measured.
Is the maximum of those calculated. (5) Thickness The cylindrical outer peripheral surface of the rolling element roller is divided into four equal parts, and each of them is equally divided into three parts in the longitudinal direction. (6) Measuring instrument For accuracy, a Laser Scan Micrometer (manufactured by Mitoyo Seisakusho) was used. Regarding the wall thickness, an ultrasonic precision thickness gauge (manufactured by K. Branson) was used.

[0024]

[Table 1]

[0025]

According to the present invention, the following effects are brought about. (1) According to the present invention, a rolling element roller having an hourglass shape can be manufactured with high precision and at a low cost by a die-less double-end expansion method which is a plastic working. (2) Since the strip material, which is the material of ERW pipe, is cold-worked by rolling rolls, the variation in wall thickness, that is, the uneven thickness amount is small. For example,
The variation in wall thickness of an electric resistance welded pipe having an outer diameter of 40 mm to 60 mm and a wall thickness of 2.0 mm or less is good at ± 0.02 mm or less on the same circumference of the pipe material and in the axial longitudinal direction. (3) By using a pipe material with a small uneven thickness as the base material, and expanding the inner diameter with a taper punch, and expanding the inner diameter in a drum shape without impairing the uniform wall thickness, especially in the case of a thin wall tube, The outer diameter can be easily formed into a drum shape by following the expansion of the inner diameter. That is, die-less pipe expansion is possible by adopting a pipe material with less uneven thickness. The rolling element roller formed here has a uniform cross-sectional shape from the both ends in the axial direction to the central portion of the drum-shaped bottom, and has a good concentricity of the inner and outer diameters on the cross section of the circular tube, unlike the cut roller. It is possible to obtain a good rolling element roller. (4) Since the wall thickness is uniform, there is little variation in the strength of the rolling element rollers, and the straightness and roundness are improved accordingly. When heating is required, heat conduction and heat storage are evenly distributed. (5) When the shape of the hourglass or less is formed by cutting, the thinner the wall, the more difficult it is to process, but in the case of pipe expansion by non-cutting, it is easy to reduce the wall thickness. When a thin rolling roller is used, for example, when it is used as a fixing roller, rapid heating due to thinning is possible, and idle time during movement of the copying machine can be shortened. (6) Resource saving effect due to press cutting, continuous mass production is possible with little variation in quality, and man-hours and cost can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a roller at a sheet passing position in a copying machine.

FIG. 2 is a diagram for explaining a manufacturing process of the electric resistance welded pipe.

FIG. 3 is a diagram for explaining another manufacturing process of the electric resistance welded pipe.

FIG. 4 is a diagram for explaining an outline of a rolling element manufacturing process according to the present invention.

FIG. 5 is a diagram for explaining a drum shape.

[Explanation of symbols]

 1 Rolling element (1a ... metal strip, 1b ... pipe forming material, 1c ... drawing material)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G03G 21/00 118

Claims (3)

[Claims] 1. A hollow cylindrical electric resistance welded tube formed and welded from a metal strip or a metal plate as a base material is formed into a large drum shape from the center to both ends by plastic working. Rolling elements such as rolling rollers. 2. The drum-shaped hollow cylindrical body is thin,
2. The rolling element such as the roller according to claim 1, wherein the thickness in the longitudinal direction and the circumferential direction is uniform or substantially uniform. 3. A metal strip or a metal plate is rolled into a welded portion by high-frequency welding to produce an electric resistance welded pipe, and if necessary, the electric resistance welded pipe is further drawn / corrected, and then both end portions thereof are fixed. A method for manufacturing a rolling element such as a roller, which is characterized in that cutting is performed and a punch having a taper is inserted from both open ends to form a large drum shape from the central part to both ends.