JP2009199008A - Roller manufacturing method for image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roller manufacturing method by which various rollers requiring outside diameter accuracy are manufactured without their surfaces being polished in the final process. <P>SOLUTION: The roller manufacturing method for the image forming apparatus includes: a first step in which a shaft 3 is fixed to an elastic urethane foam body 2a; a second step in which the elastic urethane foam body 2a is firmly inserted into the cylindrical cavity 11 of a mold 10; a third step in which the axis of the cavity 11 of the mold and the axis of the shaft 3 are aligned; and a fourth step in which the mold 10 is heated to radially compress and distort the elastic urethane foam body 2a in the mold 10 under heat. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method of manufacturing various rollers for so-called image forming apparatuses, such as electrophotographic apparatuses such as copying machines and printers, or electrostatic recording apparatuses. More specifically, the present invention relates to a stable and highly efficient cleaning. It relates to a durable cleaning roller.

  Examples of the roller for the image forming apparatus include various rollers such as a developer conveying roller, a charging roller, a transfer roller, a developing roller, a cleaning roller, and a paper feeding roller.

  For this reason, it is general that the outer surface of the roller, which requires extremely accurate outer diameter, is finished by polishing in the final manufacturing process. However, for rollers manufactured by polishing, there is a concern that polishing debris generated during polishing will adhere to the roller. Sometimes it falls and this has an unavoidable effect on the image. For this reason, it has been necessary to remove the polishing force particularly in a roller used for image generation.

  For example, Patent Document 1 discloses a cleaning roller using a melamine foam material in a roller for an image forming apparatus. In the production of such a roller, a first step of cutting a block of melamine foam into a predetermined prismatic shape, and a second step of drilling a through hole by precision hole processing in the longitudinal direction in the center of the cross section of the prismatic material, A third step in which a core material prepared in advance is inserted into the through-hole of the prismatic material and heat-bonded to form the material A; and the outer periphery of the melamine foam prismatic material of the material A is precisely pre-polished to a predetermined outer diameter. The fourth step of B, the fifth step of further press-fitting the material B into a predetermined cylindrical mold and heating it for a predetermined temperature and time, and the outer periphery of the material C extracted from the cylindrical mold after cooling. Furthermore, a method for producing a roller comprising a sixth step has been proposed which is further precisely finished and polished to obtain a roller cleaner product.

Japanese Patent Laying-Open No. 2005-241906

  That is, it has been developed that a roller with a shaft is compressed in the radial direction while performing heat treatment, and that polishing is performed after the radial compression. However, in the technique disclosed in this document, polishing processing in the final process is indispensable. Therefore, when the obtained roller is put into use, it is undeniable that a polishing residue is generated.

  The present invention provides various methods of manufacturing a roller having high outer diameter accuracy without polishing the surface in the final process in various rollers that require outer diameter accuracy.

  The gist of the present invention is that a first step of fixing a shaft to an elastic urethane foam body, a second step of press-fitting the elastic urethane foam body into a cavity of a mold having a cylindrical cavity, and a cavity of the mold For an image forming apparatus, comprising: a third step of aligning the shaft core and the shaft core; and a fourth step of heating the mold and applying a thermal compressive strain in a radial direction to the elastic urethane foam in the mold. This relates to a method for producing a roller (claim 1).

  Speaking of the first step, it is a step of press-fitting and / or adhesively fixing the shaft to the elastic urethane foam body (claim 2 or 3).

  Speaking of an example of the third step, it is a step (Claim 4) in which the tip of the cavity of the mold is formed in a mortar shape in accordance with its axial center, and the tip of the shaft is placed in the mortar.

  Moreover, before the 1st process, the pre-process (Claim 5) which punches out an elastic urethane foam body from a urethane foam raw material can be added, and the said elastic urethane foam body is a substantially cylindrical shape (Claim 6). Is preferred. When the elastic urethane foam body is non-cylindrical (Claim 7), a post-process (Claim 8) for punching the elastic urethane foam body into a substantially cylindrical shape may be added after the first step. Done.

  In the present invention, the final precision polishing process is not required by compressing the urethane foam in the radial direction in a state where the elastic urethane foam and the shaft have the same axis, thereby eliminating the residue on the roller surface. This is what we can do. In particular, the invention specified in claim 6 eliminates the need for polishing in all the steps, so that no polishing residue remains on the surface of the roller.

  The greatest feature of the present invention is that the urethane foam is thermally strained in a state where the axis of the shaft of the roller and the axis of the mold to be heat-treated are combined, and the roller is compressed in the radial direction. Since the elastic layer (urethane foam) and the shaft core coincide with each other, and the elastic layer is molded according to the cavity of the mold, the final polishing step for adjusting the outer surface of the elastic layer is unnecessary. .

  In particular, it is possible to omit any polishing process by punching a urethane foam into a cylindrical shape and using a cylinder in which a shaft is press-fitted. Furthermore, by producing a urethane foam with a round blade and heat compression molding to produce a roller with compression distortion applied to the urethane foam, the outer surface has the desired properties, and the desired processing without polishing. The roller was to be obtained.

The urethane foam used for the elastic layer of the roller preferably has a density of 0.014 to 0.070 g / cm ³ , and among them, a soft urethane foam is suitable, but a semi-rigid urethane foam may be used in some cases. In some cases, it is also possible to use a foam from which a cell film formed during foaming of a urethane foam is removed.

  The heat compression molding conditions of the urethane foam are 170 to 220 ° C., preferably 180 to 210 ° C., 300 to 1800 sec, preferably 600 to 900 sec. If the molding conditions are mild, for example, if the molding time is short, sufficient heat compression strain molding cannot be performed, and the end part spreads in a trumpet shape. If the molding time is too long, discoloration of the urethane foam occurs. There are also disadvantages of poor productivity.

  In terms of the compression rate of the urethane foam, 1.5 to 3 times, preferably 2 to 3 times, the rate of change in the radial direction of the roller is suitable.

(Specific example 1)
The present invention will be described with the roller specified in claim 5. FIG. 1 shows an overall process diagram. In FIG. 1A, a round blade cutter (not shown) for the urethane foam material A is used, and a substantially cylindrical urethane foam body 2a is cut out and cut from the urethane foam material A ( Pre-process of claim 5, claim 6).

  Next, as shown in FIG. 1B, the shaft 3 is inserted into the cylindrical urethane foam body 2a (first step, step of claim 2). Using a hot melt adhesive applied to the surface of the shaft 3, both are welded and integrated (step of claim 3). In this step, an original roller shape in which the shaft 3 penetrates the cylindrical urethane foam body 2a is obtained.

  Thereafter, as shown in FIG. 1C, the urethane foam body 2a is inserted into the cavity 11 formed in the heating mold 10 while being compressed (second step). The cavity 11 of the mold 10 is a desired roller. The diameter is the same as the outer diameter. Here, it is necessary to match the axis of the urethane foam body 2a and the shaft 3, but a jig for setting the axis to match the front and rear ends of the shaft 3 is set (third step). Such a jig is not particularly limited, but FIG. 1 (d) is an example of a preferable jig 20 for fixing the tip 3 a of the inserted shaft 3, and a mortar at the tip of the cavity 11 with respect to the tip 3 a of the shaft 3. A shaped receiver 21 is provided. The tip 3a of the shaft 3 naturally fits in the mortar-shaped receptacle 21, and the urethane foam body 2a, in other words, the cavity 11 formed in the mold 10 is set coaxially (step of claim 4). . Of course, the rear end 3b of the shaft 3 is similarly fixed.

  Finally, the mold is heated in an oven or the like to cause compression permanent deformation in the urethane foam body 2a (fourth step), and a roller having a good appearance and omitting the polishing step is obtained.

  Incidentally, in the final roller shown in FIG. 1 (e), the outer diameter of the original urethane foam body 2a is 16φ, the shaft 3 is 4φ, and the outer diameter after molding with the addition of thermal compression strain is 8φ. The roller was obtained without going through the polishing process throughout the entire process.

(Specific example 2)
The present invention will be described with the roller specified in claim 7. The entire process diagram is shown in FIG. 2, and a urethane foam material B is cut from the urethane foam material B using a cutter (not shown) in FIG. 2 (a). pre-process).

  In FIG. 2 (b), if necessary, a hole is formed in a prismatic urethane foam body 2b, and the shaft 3 is inserted into this to integrate the urethane foam body 2b and the shaft 3 as in the previous example (first step). .

  In this state, a punching process is performed to adjust the appearance of the urethane foam body 2b, and the urethane foam body 2b outside the shaft 3 is formed in a substantially cylindrical shape as shown in FIG. Process).

  FIG. 2D is equivalent to FIG. 1C (and FIG. 1D) described above, and a description thereof is omitted here.

  Finally, the mold is heated in an oven or the like to cause compression permanent deformation in the urethane foam body 2b according to the shape of the cavity 11 (fourth step), and has a good appearance and omits the polishing step in the final step. (Similar to FIG. 1 (e), not shown).

  As described above, according to the present invention, in the method of manufacturing a roller having an elastic layer made of a urethane foam material, a step of pressing the elastic layer of the roller into a cylindrical mold, and a step of heating the mold Thus, the final polishing step for obtaining the roller can be omitted, and the disadvantage caused by the polishing residue is eliminated. Therefore, the method for producing a roller of the present invention is particularly suitable for a method for producing a roller for an image forming apparatus.

It is the schematic which shows an example of the manufacturing method of the roller of this invention. It is a schematic sectional drawing which shows the other example of the manufacturing method of the roller of this invention.

Explanation of symbols

A, B ... Urethane foam material,
2a, 2b ... urethane foam,
3. Shaft,
3a: the tip of the shaft 3,
3b ... Rear end of shaft 3,
10. Heating mold,
11 Cavity,
20 ... Fixing jig,
21. A bowl-shaped receptacle.

Claims (8)

  A first step of fixing the shaft to the elastic urethane foam body, a second step of press-fitting the elastic urethane foam body into the cavity of the mold having a cylindrical cavity, and the axis of the cavity of the mold and the shaft of the shaft A method of manufacturing a roller for an image forming apparatus, comprising: a third step of aligning the core; and a fourth step of heating the mold and applying a thermal compression strain in a radial direction to the elastic urethane foam press-fitted into the cavity.   The method for manufacturing a roller for an image forming apparatus according to claim 1, wherein the first step is a step of press-fitting a shaft into the elastic urethane foam body.   The method for producing a roller for an image forming apparatus according to claim 1, wherein the first step is a step of bonding and fixing the shaft to the elastic urethane foam body.   The roller for an image forming apparatus according to any one of claims 1 to 3, wherein the third step is a step in which the tip of the cavity of the mold is formed in a mortar shape in accordance with the axis of the mold, and the tip of the shaft is placed in the mortar. Manufacturing method.   The manufacturing method of the roller for image forming apparatuses of any one of Claims 1 thru | or 4 which added the pre-process which punches out an elastic urethane foam body from a urethane foam raw material before a 1st process.   The method for producing a roller for an image forming apparatus according to claim 5, wherein the elastic urethane foam in the previous step is substantially cylindrical.   The method for producing a roller for an image forming apparatus according to claim 5, wherein the elastic urethane foam in the previous step is non-cylindrical.   The method for manufacturing a roller for an image forming apparatus according to claim 7, wherein a post-process for punching the elastic urethane foam body into a substantially cylindrical shape is added after the first process.

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