JP2000291632A - Manufacture of roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a stable roller with high close contactness between a pipe and a shaft even in case of the roller required for a lengthy size and a high torque. SOLUTION: After a pipe 2 and a metal shaft 3 are heated together, then the shaft 3 is inserted into the pipe 2 while the temperature is kept to soften a resin forming an innermost layer of the pipe 2, and cooling treatment is applied thereto. Thereafter, the pipe 2 incorporating the shaft 3 is cut to a specified size. Since the diameter of a shaft insertion hole 24 of the pipe 2 is widened and the resin is softened by the heating treatment, the shaft 3 can be inserted into the pipe 2 even if the inner diameter of the hole 24 is made smaller than a conventional case, a press-in effect is enhanced and also the pipe 2 can be fixed firmly. A smooth insertion can be made without an accident that the shaft 3 takes the heat of the pipe 2 under the way of insertion and it can not be inserted therein.

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 various rollers, for example, a roller used for transporting paper sheets in a developing machine, an OA apparatus, and the like. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Conventional roller manufacturing methods include a coating method in which unvulcanized rubber is directly coated on a shaft and an insertion method. Of these, the insertion method has a shaft insertion hole in which a resin is previously used for an inner layer. A pipe is formed by an extruder, cut into a predetermined length, and a shaft is press-fitted into a roller. In this method, since the shaft insertion hole of the pipe is formed so as to have a smaller diameter than the diameter of the shaft, the pipe can be accurately fixed to a predetermined position of the shaft by press-fitting, and even if the pipe is press-fitted, Since the resin is used for the inner layer, the shaft can be inserted into the entire pipe without being deformed by press-fitting.

On the other hand, for a roller requiring a high torque, a high degree of adhesion between the pipe and the shaft is required. Therefore, the diameter of the shaft insertion hole of the pipe whose inner layer is made of resin is further reduced, and only the pipe has a shaft. Heat until the insertion hole expands, keep the temperature at the temperature where the inner diameter of the shaft insertion hole becomes larger than the outer diameter of the shaft due to thermal expansion, insert the shaft in that state, cool it, contract it by cooling, and adhere A way to make it happen. Here, if the shaft is heated, the shaft itself also expands thermally and the outer diameter becomes large, which may hinder the insertion. Therefore, the shaft is particularly inserted without being heated.

[0004]

Generally, when a roller that is long and requires a high torque is to be manufactured, if the shaft easily enters the shaft insertion hole, the adhesion becomes poor, and a high torque is required. Since it cannot withstand and causes idling, it is preferable to press-fit the inside diameter of the shaft insertion hole as small as possible from the outside diameter of the shaft.
However, since the shaft insertion hole existing in the inner layer of the pipe is made of resin and has poor elasticity unlike rubber etc., when press-fitting the shaft into the pipe, considerable pressing is required, and if the pressing is too high, In the case of a long pipe, the pipe itself may be broken.

[0005] In addition, even if the shaft is inserted by heating the pipe to expand the shaft insertion hole by thermal expansion and insert the shaft, if the roller is long, as the shaft is inserted, the pipe is inserted. The heat given to the shaft is taken away by the shaft one after another, and the resin forming the shaft insertion hole cannot keep the expanded state due to thermal expansion,
It shrinks before insertion is complete. As a result, the shaft may not be able to be inserted halfway.

Further, if the pipe is cut to a predetermined length before cooling, the pipe is heated and a shaft is inserted.
After cooling, it depends on the diameter of the pipe and the degree of setting of the diameter of the shaft insertion hole.However, the pipe does not restore to the predetermined size, and the strain due to press-fitting is smaller than the predetermined length cut before cooling. The phenomenon that the pipe length became long was observed. As a result, there is a case where the operation of adjusting the pipe to a predetermined length after cooling is indispensable.

The present invention has been made to solve these problems, and provides a method for manufacturing a stable roller having high adhesion between a pipe and a shaft even if the roller is long and requires high torque. It is intended to be.

[0008]

In order to solve the above-mentioned problems, the present invention relates to a method of manufacturing a roller in which a metal shaft is inserted into a preformed resin pipe to form a roller. While holding both at a temperature at which the resin for the pipe softens, the metal shaft is inserted into the pipe, and then cooled to a temperature at which the resin hardens, and then the pipe covering the metal shaft is removed. It is characterized in that it is cut to a predetermined length.

Further, at least the innermost layer of the pipe is formed of a resin.

[0010]

In the method of manufacturing a roller according to the present invention, not only the pipe but also the metal shaft and the pipe are inserted at the same time by inserting the shaft while heating and keeping the temperature at a temperature at which the shaft insertion hole expands and softens. The holes expand and soften, so that no excessive pressing is required. Therefore, even if the pipe is long, the pipe does not break due to excessive pressing, and even if the metal shaft expands in diameter due to thermal expansion, the resin expands and softens, so it is inserted. Can be easily performed.

In addition, in the conventional method, particularly when manufacturing a long roller, the heat of the pipe is apt to be taken away by the shaft, which tends to make it difficult to insert the roller. When both shafts are heated and kept warm, the pipe and the metal shaft have almost the same temperature, and heat is transferred to the metal shaft in the part inserted into the pipe. The shaft can be smoothly inserted until the insertion is completed while the resin is softened without depriving the resin of heat.

Further, a metal shaft is inserted into the pipe,
After cooling, the pipe is cut to a predetermined length, so that the operation of adjusting the pipe to the predetermined size again is not required.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a view showing a process procedure of a roller manufacturing method of the present invention, and FIG. 2 is an example of a roller manufactured by using the roller manufacturing method of the present invention.

As shown in FIGS. 1 and 2, reference numeral 2 denotes a hollow cylindrical pipe formed of resin, and reference numeral 3 denotes a cylindrical metal shaft. In the embodiment to be described, as shown in FIG. 2, the pipe 2 is a roller having a two-layer pipe in which an inner layer 22 made of resin is used and an outer layer 23 covering the outer peripheral surface is made of rubber.

As shown in FIG. 1, in the forming step of FIG. 1A, the pipe 2 is formed by an extruder (not shown). The pipe 2 has a hollow cylindrical shape, and a shaft insertion hole 24 through which the metal shaft 3 is inserted is provided at the center thereof. The shaft insertion hole 24 is formed so that the inner diameter of the shaft insertion hole 24 is smaller than the outer diameter of the metal shaft 3 so that the pipe 2 can be firmly fixed to a predetermined position of the metal shaft 3. Although it varies depending on the required torque of the manufactured roller, it may be appropriately determined according to the case.

Next, in the step of heating and inserting the metal shaft 3 into the pipe 2 in FIG. 1B, the shaft insertion hole 24 is heated by using a heating device (not shown) for the pipe 2 and the metal shaft 3. The inner layer 2 of the pipe 2 is expanded by expansion.
Heat to a temperature at which the resin forming 2 softens, and keep the temperature at that temperature. In this case, the degree of softening is such that the shape of the shaft insertion hole 24 can be maintained, and from the state where the inner diameter of the shaft insertion hole 24 is increased by heating, the metal shaft 3 is further inserted by inserting the metal shaft 3. The inner diameter of the shaft insertion hole 24 is deformed according to the outer diameter of the shaft.

Next, the pipe 2 and the metal shaft 3 are inserted while being maintained at the above-mentioned temperature, the pipe 2 is positioned at a predetermined position of the metal shaft 3, and cooled in the cooling / shrinking step of FIG. I do. When cooling is performed, the inner diameter of the shaft insertion hole 24, which has been expanded and softened by thermal expansion, and has been deformed in accordance with the outer diameter of the metal shaft 3 by insertion of the metal shaft 3, contracts by cooling, and returns to the original state. Restore state. When restored, the inner diameter of the shaft insertion hole 24 is set smaller than the outer diameter of the metal shaft 3, so that the shaft insertion hole 24 is press-fitted and firmly fixed to the metal shaft 3. In addition, since the shaft insertion hole 24 is deformed in accordance with the outer diameter shape of the metal shaft 3 because the shaft is inserted in a softened state, even if the outer diameter dimensional accuracy of the metal shaft 3 is rough, it can be firmly fixed. .

After fixing the pipe 2 to the metal shaft 3,
In the cutting step shown in FIG. 1D, the pipe 2 is cut to a predetermined length, the pipe waste 21 is removed, and the roller 1 is completed. If necessary, the outer peripheral surface of the pipe 2 may be polished.

The embodiment of the present invention has been described above.
The present invention is not limited to this, and various changes can be made. For example, in the embodiment, as shown in FIG. 2, the structure of the pipe 2 is a two-layer structure. However, the pipe 2 may be a single-layer structure made of only a resin. Pipe 2 having a multilayer structure using materials other than resin for layers other than the inner layer 2
May be. Further, an example in which an extruder is used for forming a pipe has been described. However, the present invention is not limited to this. For example, the pipe may be formed using a mold.

As the material of the resin, olefin resin,
Chlorinated resins, fluorinated resins, engineering plastics resins, etc. can be used. Antioxidants, antioxidants, reinforcing agents, fillers, crosslinking agents, crosslinking aids, crosslinking accelerators, processing aids, etc. May be blended.

When rubber is used for the outermost layer of the pipe as shown in the embodiments, natural rubber, ethylene / propylene rubber, styrene / butadiene rubber, silicone rubber, EPBM, chloroprene rubber, chlorosulfonated polyethylene rubber are used. , Fluoro rubber, fluorinated silicone rubber,
Rubbers such as acrylic rubber and ethylene acrylic rubber can be used, using thermoplastic elastomers such as polystyrene-based thermoplastic elastomer, polyolefin-based thermoplastic elastomer, polyvinyl chloride-based thermoplastic elastomer, and polyester-based thermoplastic elastomer. Is also good. Of these, silicone rubber, EPBM, chloroprene rubber, and thermoplastic elastomers are suitable for the rollers used for conveying paper sheets.

The material of the metal shaft 3 is not particularly limited as long as it is a metal. In the case of a long roller requiring a high torque, the pipe 2 and the metal shaft 3 are more firmly fixed by providing knurls or the like on the outer peripheral surface of the metal shaft 3 to which the pipe 2 adheres, so that a higher torque is required. The roller 1 can withstand the above.

[0023]

According to the roller manufacturing method of the present invention as described above, since the insertion is performed while heating and keeping not only the pipe but also the pipe and the shaft, the roller is of a long type. Also, the insertion can be performed smoothly, and there is no possibility that the shaft cannot take the heat of the pipe during the insertion and cannot be inserted.

[0024] In addition, the resin forming the innermost layer of the pipe is softened not only by expanding the diameter of the shaft insertion hole, but also by changing the inner diameter of the shaft insertion hole with respect to the outer diameter of the shaft. Even if the diameter is further reduced, it becomes possible to insert the shaft, and it is possible to expect a press-fitting effect more than before. Therefore, the pipe and the shaft can be more firmly fixed, and the resin is deformed along the outer diameter shape of the shaft due to the softening of the resin. In addition, the effect of welding can be expected.

Further, since the step of cutting the pipe to a predetermined length is performed after the cooling step, there is no need to cut the pipe once to a predetermined length before heating and to adjust the pipe to a predetermined length again. Become.

[Brief description of the drawings]

FIG. 1 is a diagram showing steps of a method for manufacturing a roller according to the present invention.

FIG. 2 is a perspective view of the roller of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Roller 2 Pipe 3 Metal shaft 21 Pipe scrap 22 Inner layer part 23 Outer layer part 24 Shaft insertion hole

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J103 AA02 AA13 EA03 EA11 EA12 EA13 FA15 FA30 GA02 GA33 GA52 HA03 HA41

Claims (2)

[Claims] 1. A method for manufacturing a roller in which a metal shaft is inserted into a preformed resin pipe to form a roller, while maintaining both the pipe and the metal shaft at a temperature at which the resin for the pipe softens. Inserting the metal shaft into the pipe, cooling the resin to a temperature at which the resin hardens, and then cutting the pipe covering the metal shaft to a predetermined length. 2. The method according to claim 1, wherein at least an innermost layer of the pipe is formed of a resin.