JP2003160254A - Recording paper conveying roller and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording paper conveying roller with a fluororesin tube integrally formed on the outer surface of a core member formed of a thermoplastic resin, without providing a press-in process. <P>SOLUTION: This recording paper conveying roller 10 is provided with a cylindrical core member 11 with a rotating shaft projected on both sides, and a fluororesin tube 12 at the outer peripheral part of the core member 11. After the fluororesin tube 12 formed by extrusion molding is arranged in a molding die, the core member 11 formed of the thermoplastic resin is injection-molded inside the fluororesin tube 12 to integrally form the core member 11 and fluororesin tube 12. The fluororesin tube 12 formed by extrusion molding has excellent smoothness on the outer surface, which results in providing the recording paper conveying roller (a pinch roller, a pinch roll, a roller or a roll) of excellent nonstickiness to toner. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording paper carrier which is non-adhesive to the toner used in an image forming apparatus such as a copying machine, a printer, a facsimile or a composite machine using electrophotography. The present invention relates to a roller and a manufacturing method thereof.

[0002]

2. Description of the Related Art In the above image forming apparatus, a predetermined toner is moved onto the surface of a photosensitive drum to transfer the image on the drum onto recording paper. The recording paper on which the toner pattern is attached is sent to the fixing device, and the image is fixed on the recording paper by the heat of the heat roller and the pressure of the pressure roller. When the recording paper is discharged from the fixing device, the recording paper on which the image is fixed is passed between the discharge driving rubber roller and the pinch roller in a narrow manner. This pinch roller is required to have characteristics of non-adhesiveness to toner and releasability, since it comes into contact with toner that has just undergone the fixing process.

Therefore, as a conventional pinch roller,
Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP) or tetrafluoroethylene-ethylene copolymer (ETF
It was manufactured by using a fluororesin such as E) and integrally injecting the rotary shaft portion. However, when such a fluororesin material is manufactured by injection molding, this kind of fluororesin material is expensive, so that the pinch roller is inevitably expensive.

Therefore, as shown in FIG. 3 (a), a thermoplastic resin having excellent wear resistance and slidability is used for the core member 31 in the central portion, and PFA, FEP, ETFE or the like is used for the outer peripheral surface layer. A pinch roller 30 has been proposed in which a cylindrical member 32 formed of fluororesin is used and the cylindrical member 32 is press-fitted into the outer peripheral portion of the core member 31 to be integrated. Such a pinch roller 30 is formed as follows. That is, first, as shown in FIG. 3B, a polyacetal (polyoxymethylene: POM) resin, which is a thermoplastic resin having good wear resistance and slidability, is injection-molded to form the rotary shafts 31a and 31a. A column-shaped core member 31 protruding on both sides is formed. The maximum outer diameter of the core member 31 is formed to be the same as the inner diameter of the cylindrical member 32. Further, one core member 31 of the rotary shaft 31a
An annular projection 31b is formed at the base of the and.

On the other hand, as shown in FIG. 3 (c), a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) which is a fluororesin is injection-molded,
A cylindrical member 32 having a locking portion 32b at its end is formed.
The inner diameter of the cylindrical member 32 is formed to be the same as the maximum outer diameter of the core member 31. Further, the locking portion 32b formed at the end portion of the cylindrical member 32 has the rotating shaft 3
1a and an annular protrusion 31b formed on one side and a rotary shaft 31a
It is formed so as to be fitted between the base part of and.

Then, the pinch roller 30 as shown in FIG. 3A is formed by press-fitting the cylindrical member 32 into the core member 31. In this case, the cylindrical member 32
The side not provided with the locking portion 32b of the
1b is formed on the rotary shaft 31a side formed with
The locking portion 32b formed on the cylindrical member 32 has a rotating shaft 31a.
It is necessary to press-fit so as to fit between the annular protrusion 31b formed on one side and the base of the rotary shaft 31a.

[0007]

However, in the pinch roller formed as described above, it is necessary to form the cylindrical member by injection molding of fluororesin made of PFA. There is a problem that the smoothness of the outer surface of the member is lowered and the toner easily adheres to the pinch roller. Further, when a fluororesin made of PFA is injection-molded, an expensive molding die is required, and an injection step for molding a cylindrical member is required, which makes it impossible to easily and easily manufacture this type of pinch roller. There was a problem.

Further, since a press-fitting step of press-fitting the cylindrical member into the core member is required, there is a problem that the manufacturing process is increased and the manufacturing of this type of pinch roller is complicated and complicated. Further, since the cylindrical member formed by injection molding of fluororesin is press-fitted into the core member, dimensional accuracy of the cylindrical member and the core member is required. For this reason, the precision of the molding die for molding these cylindrical member and core member is also required, and there is a problem that the cost for manufacturing this type of molding die is further increased. Furthermore, if the cylindrical member is formed thin, there is a risk that the cylindrical member will be damaged when the cylindrical member is press-fitted into the core member. Therefore, it is necessary to form the cylindrical member to have a thick wall, which causes a problem that the amount of expensive fluororesin material used increases.

Therefore, the present invention has been made to solve the above problems, and a fluororesin tube is formed on the outer peripheral surface of a core member made of a resin material that can be injection-molded without providing a press-fitting step. It is an object of the present invention to provide a recording paper conveyance roller integrally formed and a manufacturing method capable of easily and easily manufacturing the recording paper conveyance roller.

[0010]

In order to achieve the above-mentioned object, the present invention is a recording paper conveyance provided with a cylindrical core member having a rotary shaft protruding on both sides and a fluororesin tube on the outer peripheral portion of the core member. A roller for use, characterized in that a core member made of an injection moldable resin material is integrally formed by injection molding inside a fluororesin tube formed by extrusion molding. Here, since the fluororesin tube formed by extrusion molding has excellent smoothness on the outer surface of the tube, it is difficult for toner to adhere thereto, and since it is sold as a general-purpose product, it can be obtained at low cost. Therefore, it is possible to provide a recording paper conveyance roller (sometimes referred to as a pinch roller, a pinch roll, a roller, or a roll) having excellent non-adhesiveness to toner at low cost.

Further, since the fluororesin tube formed by extrusion molding and the core member are integrated by injection molding, there is no need to insert the fluororesin tube into the core member. Thereby, a thin fluororesin tube can be used, and the amount of fluororesin material used can be reduced. Further, since it is not necessary to press fit the cylindrical member into the core member, the precision of the molding die is not required so much, and the manufacturing of the molding die for manufacturing this type of recording paper conveying roller is facilitated.

In this case, the fluororesin used for the fluororesin tube is tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PF).
A), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer The polymer (EPE), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), or polyvinylidene fluoride (PVdF) is preferable. Further, the injection-moldable resin material is preferably a thermoplastic resin or a thermosetting resin having good wear resistance and slidability.

As the thermoplastic resin, a polyacetal (polyoxymethylene: POM) resin, a polyamide (PA) resin, a polybutylene terephthalate (PBT) resin, a polycarbonate (PC) resin having good wear resistance and slidability are used. , Acrylonitrile-butadiene-styrene (ABS) resin, and liquid crystal polymer (LCP) are preferably used. As the thermosetting resin, it is preferable to use a phenol (PF) resin, an epoxy (EP) resin, a polyimide (PI) resin, or the like.

In order to manufacture the recording paper conveying roller in which the fluororesin tube formed by extrusion molding and the core member are integrated by injection molding as described above, the fluorine formed by extrusion molding is used. A cutting step of cutting the resin tube into a predetermined length, a resin tube arranging step of arranging the fluororesin tube cut into a predetermined length in the molding die, and a fluororesin tube in the molding die in which the fluororesin tube is arranged. An injection step of injecting a thermoplastic resin or a thermosetting resin to form a cylindrical core member with a rotary shaft protruding to both sides may be provided, and this type of recording paper conveying roller (pinch roller). Can be manufactured easily and easily.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described in detail with reference to FIGS. 1A and 1B are views showing a pinch roller (recording paper conveying roller) according to an embodiment of the present invention, FIG. 1A is a front view, and FIG. 1B is a sectional view. 2 is a sectional view showing a section of a molding die for molding the pinch roller shown in FIG. The pinch roller 10 of the present embodiment is shown in FIG.
As shown in (a) and (b), a core member 11 formed of a thermoplastic resin having good wear resistance and slidability, and a fluororesin tube 12 formed on the outer peripheral surface of the core member 11. It is composed of

The core member 11 has rotating shafts 11a,
The protrusion 11a is formed into a columnar shape having annular protrusions 11b and 11b at both ends of its outer peripheral surface. The core member 11 is formed by injection molding using a thermoplastic resin having excellent wear resistance and slidability. The fluororesin tube 1 is provided between the annular protrusions 11b, 11b formed at both ends of the outer peripheral surface of the core member 11.
2 is integrally formed at the time of injection molding of the core member 11. As the thermoplastic resin, polyacetal (polyoxymethylene: PO) having good wear resistance and slidability is used.
M) resin, polyamide (PA) resin, polybutylene terephthalate (PBT) resin, polycarbonate (PC)
Resin, acrylonitrile-butadiene-styrene (AB
It is desirable to use S) resin and liquid crystal polymer (LCP). Further, a thermosetting resin may be used instead of the thermoplastic resin. In this case, as the thermosetting resin, phenol (P
F) resin, epoxy (EP) resin, polyimide (PI)
It is desirable to use a resin or the like.

The fluororesin tube 12 is a tube (SUPE manufactured by Mitsui DuPont Fluorochemical Co., Ltd.) formed by extrusion molding a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA).
R PFA 451 HP-J: PFA tube) is cut into a predetermined length (for example, 12 mm) and used. The fluororesin tube 12 is formed to have a wall thickness of 0.5 mm, an outer diameter dimension of 8 mm, and an inner diameter dimension of 7 mm.

As the fluororesin material used for the fluororesin tube 12, in addition to PFA described above, polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FE
P), tetrafluoroethylene-ethylene copolymer (E
TFE), tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer (EPE), polychlorotrifluoroethylene (PC
TFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), polyvinylidene fluoride (P
VdF) or the like may be used.

Next, a method of manufacturing the pinch roller 10 configured as described above will be described with reference to FIG. First, the upper mold 21 and the lower mold 22 shown in FIG. 2 were prepared. In addition, in the upper die 21, a groove portion 21a for forming the rotating shaft 11a is formed.
And an annular groove portion 21b for forming the annular protrusion 11b.
And a resin injection opening 21c for injecting a thermoplastic resin
And are formed. Further, the rotary shaft 11 is provided in the lower mold 22.
a groove portion 22a for forming a, an annular groove portion 22b for forming the annular protrusion 11b, and the fluororesin tube 1
An annular groove portion 22c for arranging 2 is formed.

On the other hand, a PFA tube (for example, a wall thickness of 0.5 mm, an outer diameter dimension of 8 mm, and an inner diameter dimension of 7 mm)
Cut into a predetermined length (for example, 12 mm),
After forming the fluororesin tube 12, the fluororesin tube 12 was placed in the annular groove portion 22 a formed in the lower mold 22. After that, the upper mold 21 was placed on the upper part of the lower mold 22 on which the fluororesin tube 12 was arranged, and then these were clamped. Next, the resin injection opening 21c formed in the upper mold 21 and the injection nozzle provided in the injection molding device (not shown) were connected.

After this, the resin injection opening 21 from the injection nozzle.
By injecting the molten thermoplastic resin or thermosetting resin into c, the fluororesin tube 12 is integrated between the annular projections 11b and 11b on the outer peripheral surface of the core member 11 from which the rotating shafts 11a and 11a project on both sides. Will be formed. Then, the upper die 21 is removed from the lower die 22, and the formed body formed in the lower die 22 is taken out, whereby the core member 11 and the fluororesin tube 12 formed on the outer peripheral surface of the core member 11 are removed. Pinch roller 1 configured
0 will be obtained.

[0022]

As described above, in the recording paper conveying roller (pinch roller, pinch roll, roller, roll) 10 of the present invention, fluorine formed by extrusion molding having excellent smoothness on the outer surface of the tube. Since the resin tube 12 is used, it is possible to provide a recording paper conveyance roller (pinch roller) having excellent non-adhesiveness to toner. Further, since the fluororesin tube 12 is sold as a general-purpose product, it can be obtained at low cost. Therefore, it is possible to inexpensively provide a recording paper transporting roller (pinch roller, pinch roll, roller, roll) having excellent non-adhesiveness to toner.

Further, since the fluororesin tube formed by extrusion molding and the core member are integrated by injection molding, there is no need to insert the fluororesin tube into the core member. Thereby, a thin fluororesin tube can be used, and the amount of fluororesin material used can be reduced. Further, since it is not necessary to press-fit the cylindrical member into the core member, the precision of the molding die is not required so much, and this type of recording paper transport roller (pinch roller, pinch roll, roller, roll) is manufactured. The mold is easily manufactured.

In the above-described embodiment, an example in which a single recording paper conveying roller (pinch roller, pinch roll, roller, roll) 10 is manufactured has been described. It is general that (8 to 8) recording paper conveying rollers are attached to a mounting portion provided on the frame. Therefore, this type of recording paper transport roller (pinch roller, pinch roll, roller, roll)
Rotating shafts 11a, 11a of the plurality of rollers 10 such that a plurality of 10 (for example, 2 to 8) are integrally connected.
May be integrally formed. By using the recording paper conveying roller in which a plurality of rollers are integrally formed in this way, the work of attaching each roller 10 to the mounting portion becomes easy.

[Brief description of drawings]

FIG. 1 is a diagram showing a recording paper transporting roller (pinch roller, pinch roll, roller, roll) of the present invention, FIG. 1 (a) is a front view, and FIG. 1 (b) is a sectional view. .

FIG. 2 is a cross-sectional view showing a cross section of a molding die for molding the recording paper transporting roller (pinch roller, pinch roll, roller, roll) shown in FIG.

3 is a diagram showing a conventional pinch roller, and FIG.
FIG. 3A is a front view in which a part thereof is cut away, and FIG.
Is a front view showing a core member used for this pinch roller, and FIG. 3 (c) is a sectional view showing a cylindrical body used for this pinch roller.

[Explanation of symbols]

10 ... Roller for conveying recording paper (pinch roller, pinch roll, roller, roll), 11 ... Core member, 11a ... Rotating shaft,
11b ... Annular protrusion, 12 ... Fluororesin tube, 21 ...
Upper mold, 21a ... Groove part, 21b ... Annular groove part, 21c ... Resin injection opening, 22 ... Lower mold, 22a ... Annular groove part, 22b ... Annular groove part, 22c ... Annular groove part

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) B29K 105: 20 B29K 105: 20 627: 12 627: 12 B29L 9:00 B29L 9:00 31:32 31:32

Claims (4)

[Claims] 1. A recording paper conveying roller comprising a cylindrical core member having a rotary shaft protruding on both sides and a fluororesin tube on an outer peripheral portion of the core member, the fluororesin being formed by extrusion molding. A recording paper conveying roller, wherein the core member made of a synthetic resin material that can be injection-molded is integrally formed inside the tube by injection molding. 2. The fluororesin is a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (P
FA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer The polymer (EPE), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), or polyvinylidene fluoride (PVdF), which is any one of claims 1 to 3, wherein Recording paper transport roller. 3. The injection-moldable synthetic resin material is a thermoplastic resin or a thermosetting resin having good wear resistance and slidability.
The recording paper conveyance roller described in 1. 4. A method for manufacturing a recording paper conveying roller comprising a cylindrical core member having a rotary shaft protruding to both sides and a fluororesin tube on an outer peripheral portion of the core member, the roller being formed by extrusion molding. A cutting step of cutting the fluororesin tube into a predetermined length, a fluororesin tube arranging step of disposing the fluororesin tube cut into the predetermined length in a molding die, and the fluororesin tube being arranged An injection step of injecting a thermoplastic resin or a thermosetting resin, which becomes a cylindrical core member with the rotary shaft protruding to both sides, into a molding die, and manufacturing the recording paper transporting roller. Method.