JPH09120231A - Cylindrical support body for electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a support body which consists principally of PPS resin or polyphthalamide resin and rotates on a cylinder shaft without any play and can excellently be grounded and is superior in heat resistance and chemical resistance stability, easy to manufacture, and inexpensive. SOLUTION: A cylindrical base part 1a, a flange part 2a which has a gear 3a and a through hole 4 for a metallic shaft formed at one end of the base part 1a, and a flange part 2b which has a gear 3b and a through hole 4 for the metallic shaft formed at the other end are coaxially molded in one body of a material consisting principally of PPS resin or polyphthalamide resin with which carbon black is mixed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a cylindrical support for an electrophotographic photoreceptor.

[0002]

2. Description of the Related Art An organic photoconductor for electrophotography, which is used in an electrophotographic device (hereinafter referred to as a main body device) such as a copying machine or a printer to which electrophotographic technology is applied, has a conductive property that also serves as one electrode of the photoconductor. It is composed of a support and a photosensitive layer formed on the support and made of an organic material containing an organic photoconductive material. The conductive support is usually formed into a cylindrical shape because of its advantage in device design, and a photosensitive layer is formed as a coating film on the outer peripheral surface of the conductive support to form a cylindrical photosensitive body.

In the main body device, such a cylindrical photosensitive member is mounted on the main body device so as to be rotatable about its cylindrical axis, and for image formation, the photosensitive member is rotated about the cylindrical shaft. While continuously rotating as, while charging the surface,
It is carried out by exposing an image to form an electrostatic latent image, developing it with a developer containing toner, and transferring and fixing the toner image onto a support such as paper. The toner image transfer standard photoconductor is
After the surface is cooled and the charge is removed, it is repeatedly used for image formation.

As a material for the cylindrical support, aluminum or an aluminum alloy, which is relatively weighed and has good machinability, has been frequently used. On the other hand, Tokuhei 2-1
No. 7026 discloses a polyphenylene sulfide resin (hereinafter, referred to as PPS resin) as a cylindrical support suitable for a photoconductor, which is lighter in weight, has excellent chemical resistance and heat resistance, does not undergo deterioration such as oxidation even in the air, and is suitable for a photoreceptor. A support produced by an injection molding method using a material mainly composed of

A flange having a through hole for a metal shaft is attached to an end portion of the support, and the metal shaft through hole for the metal shaft of the flange is passed through the metal shaft disposed on the main device side to the main body device. By mounting the photoconductor, the photoconductor is rotatably mounted on the main body device about its cylindrical axis. A gear for transmitting the rotational driving force from the main body is formed on the flange at one end of the support. The flange is usually press-fit by applying an adhesive to a flange fitting portion provided at the end of the support. Further, it is necessary that the support as one electrode of the photoconductor is grounded. When the flange is made of a conductive material, when the photoconductor is mounted on the main body device, the support is electrically connected to the metal shaft by the flange, so that the support can be grounded through the metal shaft. In recent years, in order to reduce the weight, resin flanges have come to be used, but in that case, a gear that normally transmits the rotational driving force from the main body device when the flange is attached to the support body is used. The support is grounded by simultaneously mounting a conductive member, for example, a metal spring, on the flange side having the so that the support and the metal shaft are electrically connected.

[0006]

In the electrophotographic apparatus, in order to obtain a good image, the photosensitive member is required to rotate with its cylindrical axis as a rotation axis and with high accuracy without blurring. For this purpose, the flange attached to the support must be firmly fixed to the support so that its axis is coaxial with the cylindrical axis of the support. It is technically difficult to fix them coaxially with high precision by press fitting.

Further, as described above, the support needs to be grounded in order to function as one electrode of the photoconductor. For this reason, when the flange is made of resin, the conductive member is attached at the same time when the flange is attached, but it takes man-hours to attach it securely so that the support and the metal shaft are electrically conducted, and the support is made of resin. However, there is a problem of contact resistance, and there is also a problem that a conductive adhesive must be used for adhesive press-fitting.

The present invention has been made in view of the above points, and is a cylindrical support for a photosensitive member containing a resin as a main component, and the photosensitive member is not shaken around its cylindrical axis. An object of the present invention is to provide a support which can be rotated with high precision, has a mechanism capable of properly grounding the support, has excellent heat resistance and chemical stability, and is easy to manufacture and inexpensive. .

[0009]

SUMMARY OF THE INVENTION According to the present invention, the above-mentioned problem is solved by providing a cylindrical base portion and a gear and a metal shaft through hole located at both ends thereof for transmitting a rotational driving force to the base portion. The problem is solved by forming the flange portion having the same into a cylindrical support for an electrophotographic photoreceptor, which is integrally formed of a material containing a PPS resin or a polyphthalamide resin mixed with carbon black as a main component.

By adding carbon black to the PPS resin or the polyphthalamide resin, the support is provided with the conductivity required for the support of the photoreceptor. Also, since the base portion and both flange portions are integrally molded,
Both can easily be made completely coaxial, and the blurring of the rotation of the photoconductor due to the disagreement of the coaxiality between the two can be substantially eliminated. Further, since the flange portion is also made of the same material as the base portion, the support body should be properly grounded through the metal shaft on the main body side that is inserted into the through hole for the metal shaft when mounted on the main body. become. Also,
The rotational driving force from the main body device is transmitted to the photoconductor through the gear on one of the flanges of the support. In that case,
If necessary, the other flange can serve to transmit the rotational driving force to the outside of the photoconductor through the gear thereof.

The gear provided on the flange may have either helical teeth or spur teeth. Further, instead of providing the through hole for the metal shaft in the flange, it is possible to facilitate the metal shaft in advance and integrally mold the metal shaft at the same time. In this case, since the flange made of resin and the metal shaft are fixed by integrally molding including the metal shaft, sliding during rotation of the photosensitive member is made of the metal shaft and the metal from between the metal shaft and the through hole. We will move on to sliding between the bearings. As a result, wear between the flange and the through hole for the metal shaft is eliminated, so that the rotational driving of the photoconductor can be maintained more stably.

The integral molding can be easily and inexpensively performed by the injection blow molding method. At this time, if the flange portion of the mold is nested so that it can be changed according to the shape and size of the flange, it becomes possible to easily manufacture a support having different types of flanges. Further, the above-mentioned problem is to provide a cylindrical base portion made of a material whose main component is a PPS resin or a polyphthalamide resin mixed with carbon black, and a through hole for a gear and a metal shaft is provided at one end of the base portion. Then
And a conductive member that electrically connects the flange and one of the flanges preformed with a PPS resin or a polyphthalamide resin mixed with a fluororesin or carbon fiber having excellent sliding wear characteristics and the metal shaft to each other.
Further, at the other end, there is a gear and a through hole for a metal shaft, and the other flange preformed with a PPS resin or polyphthalamide resin mixed with a fluororesin or carbon fiber having excellent sliding wear characteristics. The problem is solved by providing a cylindrical support for an electrophotographic photosensitive member, which is integrally molded by the double molding method with the same material as the material for forming the base portion.

Since the flange is formed of a material having excellent sliding wear characteristics, it is possible to reduce wear of the gear and wear of the through hole for the metal shaft due to rotational driving of the support, and rotational driving of the photoconductor. Can be maintained well.
In addition, the grounding of the support body is surely performed by the conductive member integrally molded at the same time. The base, the flange, and the conductive member can be integrated by a double molding method easily by using a mold, and the coaxiality of the two is improved. Further, also in this case, by using a flange integrally formed with the metal shaft instead of the flange having the through hole for the metal shaft, sliding between the flange and the metal shaft is prevented by the metal shaft and the bearing made of metal. It is possible to shift to sliding between them, wear of the through hole for the metal shaft of the flange can be eliminated, and stable rotation drive of the photoconductor can be maintained.

As described above, the support is made of a material containing PPS resin or polyphthalamide resin as a main component, including the base portion and the integrated flange portion or flange. Good heat resistance and chemical stability.

[0015]

FIG. 1 is a longitudinal sectional view showing an embodiment of a support according to the present invention, which is for a cylindrical base portion 1a, a helical gear 3a provided at one end thereof, and a metal shaft. The flange portion 2a having the through hole 4, the spur gear 3b provided at the other end, and the flange portion 2b having the through hole 4 for the metal shaft are mainly composed of PPS resin or polyphthalamide resin containing carbon black. 2 shows a support integrally formed by injection blow molding with the above material.

In order to integrally form the flange portions at both ends in this way, the mold for forming the cylindrical base portion is a half mold, and cavities for forming flange portions are provided at both ends. A parison is formed from a cavity portion of a flange portion having a helical gear, and air blow molding is performed to obtain an integrally molded product. When releasing the mold, it is possible to open the mold of the two-divided portion, move and remove the flange portion having the spur teeth, and then knock out while rotating the flange portion having the helical teeth to take it out of the mold. By changing the insert, the cavity part of the flange has a nested structure,
It is possible to obtain a support having a flange with gears of a size.

Further, by setting the metal shaft 5 at the position of the through hole 4 for the metal shaft and simultaneously integrally molding it, a support body integrally molded including the metal shaft 5 as shown by a dotted line can be obtained. FIG. 2 is a vertical cross-sectional view showing another embodiment of the support according to the present invention, which is a cylindrical base portion 1b made of a material whose main component is PPS resin or polyphthalamide resin mixed with carbon black.
And a helical gear 3 pre-molded with a PPS resin or a polyphthalamide resin in which a fluororesin or a carbon fiber, which is separately excellent in sliding wear characteristics, is added to one end thereof.
a, a flange 2c having a through hole 4 for the metal shaft, a conductive member 6 for electrically connecting the base portion 1b and the metal shaft, and a fluororesin or carbon fiber having another excellent sliding wear property at the other end. Compounded P
1 shows a support body in which a spur gear 3b preformed by PS resin or polyphthalamide resin and a flange 2d having a through hole 4 for a metal shaft are made of the same material as the base portion 1b by a double molding method.

Such a support has a cylindrical base portion 1b.
The mold for forming is made into two halves, the flange 2c and the conductive member 6, and the flange 2b at the other end are set at one end, and molded by the double molding method using the same material as the base 1b. When demolding, open the mold in two parts and take out the molded product. Also in this case, by using the flange in which the metal shaft is integrally formed in advance, an integrated support including the metal shaft 5 as shown by the dotted line can be obtained.

In the above-described embodiment, the gear provided on the flange has teeth with one end having a helical tooth and the other end having a flat tooth. However, the type of tooth is not limited to this, and may be replaced. Both may be the same type, or may be another different type. The shape of the flange and the shape of the conductive member are not limited to those illustrated above.

[0020]

Since the present invention is constructed as described above, the following effects can be obtained. By using the support body in which the cylindrical base portion and the flange portions at both ends thereof are integrally formed, the number of steps for adhesively press-fitting the flange into the base portion is eliminated, and both are securely fixed. Furthermore, both can be easily made coaxial, and the rotational drive of the photoconductor can be performed in good rotation without blurring. In addition, since the integrally molded material has conductivity, it is not necessary to separately provide a conductive member for electrically connecting the base portion and the metal shaft to the flange portion, which reduces the number of parts and the number of mounting steps. Therefore, reliable grounding can be obtained. Furthermore, by integrally forming the metal shaft, the concentricity of the base portion, the flange portion, and the metal shaft is improved, so that the rotational driving of the photosensitive member is further improved, and the sliding between the flange portion and the metal shaft Is also eliminated, so that there is an advantage that the life of the photoconductor is extended.
PP blended with carbon black as an integrally molded material
By using a material containing S resin or polyphthalamide resin as a main component, a support having excellent heat resistance and chemical stability can be obtained.

PPS containing carbon black
Flange and base part made of PPS resin or polyphthalamide resin in which one end of a cylindrical base part made of resin or polyphthalamide resin as a main component is blended with a separately manufactured material having excellent sliding wear characteristics The PPS in which the conductive member for electrically connecting the metal shaft and the metal shaft is blended with the separately manufactured material having excellent sliding wear characteristics at the other end.
Flange made of resin or polyphthalamide resin,
By forming the support integrally by the double molding method, the same effect as described above can be obtained, and the sliding portion of the flange with respect to the metal shaft and the wear of the gear can be significantly improved. Further, by using the flange in which the metal shaft is integrally formed in advance, sliding between the flange and the metal shaft is eliminated, so that the wear resistance of the flange is further improved. Since the support is made of a material containing PPS resin or polyphthalamide resin as a main component, including the base portion and the flange portion or the flange, a support having excellent heat resistance and chemical stability can be obtained. .

[Brief description of the drawings]

FIG. 1 is a schematic vertical sectional view of an embodiment of a support according to the present invention.

FIG. 2 is a schematic vertical sectional view of another embodiment of the support according to the present invention.

[Explanation of symbols]

 1a, 1b Base part 2a, 2b Flange part 2c, 2d Flange 3a, 3b Gear 4 Through hole for metal shaft 5 Metal shaft 6 Conductive member

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B29K 81:00 B29L 22:00 31:00

Claims (6)

[Claims] 1. A cylindrical base portion, and flange portions located at both ends of the base portion, each of which has a gear for transmitting a rotational driving force to the base portion and a through hole for a metal shaft, are polyphenylene sulfide resin or poly containing carbon black. A cylindrical support for an electrophotographic photosensitive member, which is integrally formed of a material containing a phthalamide resin as a main component. 2. A cylindrical support for an electrophotographic photosensitive member according to claim 1, wherein the metal shaft is inserted into a through hole for a metal shaft of at least one flange portion and integrally molded. 3. The cylindrical support for an electrophotographic photosensitive member according to claim 1 or 2, which is integrally molded by an injection blow molding method. 4. The cylindrical support for an electrophotographic photosensitive member according to claim 1, wherein the shape of the gear is a helical tooth or a flat tooth. 5. A cylindrical base portion made of a material whose main component is polyphenylene sulfide resin or polyphthalamide resin mixed with carbon black, and a gear and a through hole for a metal shaft are provided at one end of the base portion. And a conductive member for electrically conducting the one flange preformed with a polyphenylene sulfide resin or a polyphthalamide resin mixed with a fluororesin or carbon fiber having excellent sliding wear characteristics and the base portion to a metal shaft. In addition, the other end has a through hole for gears and a metal shaft, and the other flange formed of polyphenylene sulfide resin or polyphthalamide resin mixed with fluorine resin or carbon fiber, which also has excellent sliding wear characteristics. Polyf blended with carbon black An electrophotographic photoreceptor cylindrical support, characterized by comprising integrated by double molding method using a material mainly composed of two sulfide resin or polyphthalamide resin. 6. A flange integrally molded with a conductive member at one end of a cylindrical base member by a double molding method is a flange formed by inserting a metal shaft into a through hole for a metal shaft and molding the same. A cylindrical support for an electrophotographic photosensitive member according to claim 5.