JPH0566910U - Magnet device - Google Patents

Abstract

(57) [Summary] [Purpose] We do not provide a structure in which a synthetic resin flange with low dimensional accuracy obtained only by molding is used as it is and can be firmly fixed to the metal sleeve without causing deformation of the metal sleeve. The purpose of this is to contribute to the provision of an inexpensive magnet device. [Structure] One or both of the flanges is a synthetic resin molded product, and the synthetic resin flange has a shaft hole (7) for axially supporting the shaft of the magnet roll and an annular standing wall (8) that is a fitting portion for the sleeve. And a notch (9) formed in the annular standing wall (8) that allows elastic deformation of the annular standing wall.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a magnet device used in an electrostatic developing device such as a copier for plain paper, a printer, and a facsimile.

[0002]

[Prior Art]

 Magnet devices are used in electrophotographic developing devices and cleaning devices such as copiers and facsimiles. As shown in the sectional views of FIGS. 5 (a) and 5 (b), this magnet device is a magnet roll M constructed by penetrating a shaft 2 in a cylindrical magnet body 1 and has flanges 3a and 3b at both ends. This is a configuration in which a closed cylindrical sleeve S is internally mounted. The shaft portion 2b on one end side of the shaft 2 is guided by the bearing 4b incorporated in the flange 3b while penetrating the flange 3b and led out to the outside of the flange 3b. The portion 2a is configured so as to be axially supported by a bearing 4a incorporated in the flange 3a without penetrating the flange 3a, and a shaft portion 5 projecting on the outer surface of the flange 3a is provided with a shaft portion 2b on one end side of the shaft 2a. The magnet roll M and the sleeve S can be rotated relative to each other by rotating relative to each other.

[0003]

[Problems to be solved by the device]

 By the way, in such a magnet device, the flanges 3a and 3b are made of a metallic material, but the metallic flange is heavy and the manufacturing cost is high. In order to deal with such a problem, it has been proposed to fabricate the flange using a synthetic resin, and in particular, when the flange itself needs conductivity, it is attempted to mold the flange using a conductive resin. Has been. Although it is possible to manufacture the flange by injection molding or compression molding by making the flange made of synthetic resin, the dimensional accuracy required for the flange cannot be obtained only by molding, so the synthetic resin flange Then, post-processing such as cutting was necessary. Especially, the fitting part of the flange to the sleeve also serves as the driving force transmission part to the sleeve, so it is necessary to firmly fix it to the inner peripheral surface of the sleeve, but a metal sleeve such as aluminum or stainless steel and a synthetic resin flange are strong. Since there is no suitable adhesive that can be bonded to the flange, the only conventional method for firmly fixing the flange and sleeve is to tighten the dimensional accuracy of the flange mating part to increase the mating force to the sleeve. It was If simply increasing the fitting force, it is considered to press-fit the flange with the outer diameter of the fitting part slightly larger than the inner diameter of the sleeve to be fitted into the sleeve, but with such a method As shown in FIG. 6, there is a problem that the end of the sleeve swells, which is not preferable.

In the conventional method for increasing the fitting force by bringing the outer diameter dimension of the flange fitting section closer to the inner diameter dimension of the sleeve in this way, extremely strict dimensional tolerance is required for the flange fitting section. As a result, the processing cost increases, and the original purpose of reducing the cost of the magnet device cannot be achieved by using the synthetic resin flange. The present invention has been made in view of the current situation, and a synthetic resin flange with low dimensional accuracy obtained only by molding is used as it is, and it is firmly attached to the metal sleeve without causing deformation of the metal sleeve. The purpose is to provide a structure that can be fixed, thereby contributing to the provision of an inexpensive magnet device.

[0005]

[Means for solving the problem]

 In the present invention, which solves such a problem, a synthetic resin molded product is used for one side or both sides of the flange, and the synthetic resin flange serves as a fitting portion for a shaft hole for supporting a shaft of a magnet roll and a sleeve. It is characterized in that it has an annular standing wall, and that the annular standing wall is formed with a notch for elastic deformation. It is preferable to arrange the flanges having the above-mentioned configuration at both ends of the sleeve, but it is also possible to adopt the flange having the above-mentioned configuration only on one side of the flange that serves as a driving force transmitting portion.

It is preferable that a plurality of cuts are provided in the fitting portion of the synthetic resin flange at equal intervals along the axial direction of the flange, and the outer diameter of the fitting portion of the synthetic resin flange is the object to be fitted. The inner diameter of the sleeve is preferably 0.03 mm to 0.06 mm.

[0007]

[Action]

 Assembling the flanges to the sleeve in the magnet device having such a configuration is performed by internally fitting and fixing the flanges, to which the fitting portions are coated with the adhesive, at both ends of the sleeve into which the magnet roll is inserted, as in the conventional case. In the present invention, since the notch for elastic deformation is made in the annular standing wall that is the fitting portion of the synthetic resin flange, the fitting portion can be elastically contracted inward in the radial direction of the flange, and the sleeve end portion After the fitting, the annular standing wall moderately presses the end of the metal sleeve from the inner peripheral surface side by the elastic restoring force to firmly bond the flange and the sleeve. Therefore, even if the rotational force is transmitted to the sleeve through the flange, the flange and the sleeve do not idle around each other due to defective adhesion during use. Moreover, since the force pressing the metal sleeve end from the inner peripheral surface side is due to the elastic restoring force, it is neither too strong nor deforms the sleeve end. It is important to note that such a flange, when fitted inside the sleeve, causes the outer diameter of the fitting part to elastically contract and automatically match the inner diameter of the sleeve. There is no need to tighten the pressure, and it is possible to use a flange that has not been post-processed just by injection molding or compression molding, which reduces the cost of the flange and contributes to the cost reduction of the magnet device. be able to .

[0008]

【Example】

 Next, the details of the present invention will be described based on the illustrated embodiment. 1 to 3 show an embodiment of a synthetic resin flange used in the magnet device of the present invention. FIG. 1 is a perspective view, FIG. 2 (a) is a front view, (b) is a side view, and FIG. 3 is a shaft. It is a direction end view. The synthetic resin flange 6 has an axial hole 7 for axially supporting the shaft 2 of the magnet roll M in the center of the inner surface, and an annular standing wall 8 which is a fitting portion for the sleeve is formed around the shaft hole 7, and this annular standing wall is also formed. A plurality of notches 9, 9 ... Are formed in the axial direction 8 at equal intervals, and the annular standing wall 8 is divided into a plurality of elastic pieces 10, 10.

As shown in FIG. 2, the groove width d of the notch 9 is preferably set to 0.5 mm to 1.5 mm, and as shown in FIG. 4, the annular standing wall 8 which is the fitting portion of the synthetic resin flange. It is preferable to set the outer diameter r of the sleeve S to be slightly larger than the inner diameter R of the sleeve S to be fitted to enhance the fitting force to the sleeve, and the outer diameter r of the annular standing wall 8 is larger than the inner diameter R of the sleeve S. It is preferable to set it large by about 0.03 mm to 0.06 mm. Although the outer diameter of the annular standing wall 8 is not strict, it should be noted that the sleeve S may be deformed if the outer diameter r of the annular standing wall is too large.

Examples of the material of the flange 6 include so-called engineering materials such as polyacetal, ABS resin, polyamide, polycarbonate, polyphenylene oxide, polyphenylene sulfide, polysulfone, polyethylene terephthalate, polybutylene terephthalate, and polyether ether ketone. Plastics and other thermosetting resins such as phenol resin and epoxy resin can be used. These synthetic resins are suitable for use as flanges because they have excellent molding accuracy, mechanical strength, and abrasion resistance.

It is also possible to disperse and blend a conductive filler in the synthetic resin to impart conductivity to the flange. As the conductive filler, for example, carbon fiber, metal powder, carbon powder or the like can be used. When conductivity is imparted to the flange in this manner, an electric potential can be applied to the sleeve via the flange, as in the case of using a conventional metal flange. It is also possible to fill the synthetic resin with other inorganic fillers together with the conductive filler for the purpose of increasing the mechanical strength, for example, by filling glass fiber, talc, titanium oxide, alumina, carbon powder, molybdenum oxide, etc. Good. In particular, when a proper amount of slidable filler such as talc or molybdenum oxide is filled, the sliding resistance of the magnet roll M with the shaft 2 can be reduced, and the rotating operation becomes smoother.

Injection molding or compression molding can be adopted as a method of molding such a synthetic resin flange 6, but injection molding is generally preferable. The flange made of synthetic resin is assembled into the sleeve as it is without using post-processing such as cutting after molding.

To attach the synthetic resin flange 6 to the sleeve, after applying an adhesive to the outer surface of the annular standing wall 8 of the synthetic resin flange 6, the annular standing wall 8 which is a fitting portion is sleeved as shown in FIG. This is done by fitting it in S. The annular standing wall 8 is divided into a large number of elastic pieces 10, 10 ... By the notches 9, 9 ... And the annular standing wall 8 is configured to be capable of contracting inward in the radial direction. Even if the outer diameter of the ring is slightly larger than the inner diameter of the sleeve, the annular standing wall 8 can be easily fitted in the sleeve. Moreover, since the annular standing wall 8 press-fitted into the sleeve presses the sleeve from the inside by the elastic restoring force, the fitting force of the flange with respect to the sleeve becomes extremely strong.

[0014]

[Effect of the device]

 The magnet device of the present invention uses a synthetic resin molded product for the flange on one side or both sides, and the notch for elastic deformation is made in the annular standing wall that is the fitting part of the synthetic resin flange. It is possible to elastically contract the annular standing wall toward the inner side in the radial direction of the flange, which facilitates the fitting of the flange to the sleeve end part, and after the fitting, the annular standing wall keeps the end part of the metal sleeve from fitting. Since the inner peripheral surface side is pressed appropriately, the flange and the sleeve can be firmly bonded and fixed. Moreover, since the force pressing the metal sleeve end portion from the inner peripheral surface side is due to the elastic restoring force, it is neither too strong nor deforms the sleeve end portion. When such a flange is fitted into the sleeve, the outer diameter of the fitting part elastically contracts and automatically matches the inner diameter of the sleeve, so the dimensional tolerance of the flange fitting part is tightened. It is not necessary to use a flange that has not been post-processed by injection molding or compression molding, and the flange cost can be reduced, which in turn contributes to cost reduction of the magnet device. it can.

[Brief description of drawings]

FIG. 1 is a perspective view showing one embodiment of a synthetic resin flange used in a magnet device of the present invention.

FIG. 2 shows a synthetic resin flange of the same embodiment, (a)
Is a front view, (b) is a side view

FIG. 3 is an axial end view of the synthetic resin flange of the embodiment.

FIG. 4 is an explanatory view showing a state where the synthetic resin flange of the embodiment is assembled to a sleeve.

FIG. 5 shows a conventional magnet device, in which (a) is an axial sectional view and (b) is a radial sectional view.

FIG. 6 is a cross-sectional explanatory view showing a state in which a flange having a fitting portion having an outer diameter slightly larger than the inner diameter of the sleeve is strongly pressed into the sleeve in the conventional magnet device.

[Explanation of symbols]

 S sleeve M magnet roll 1 magnet body 2 shaft 2a one end side shaft part 2b other end side shaft part 3a, 3b flange 4a, 4b bearing 5 shaft part 6 synthetic resin flange 7 shaft hole 8 annular standing wall 9 notch 10 elastic piece

Claims (3)

[Scope of utility model registration request] 1. A magnet device in which a magnet roll is rotatably housed inside a cylindrical sleeve whose both ends are closed by flanges, wherein one or both flanges are synthetic resin molded products, A magnet device in which a synthetic resin flange has an axial hole that axially supports a shaft of a magnet roll and an annular standing wall that serves as a fitting portion for a sleeve, and a notch for elastic deformation is formed in the annular standing wall. 2. The magnet device according to claim 1, wherein a plurality of cuts provided in the fitting portion of the synthetic resin flange are provided at equal intervals along the axial direction of the flange. 3. The outer diameter of the fitting portion of the synthetic resin flange is
The inner diameter of the sleeve to be fitted is 0.03 mm to 0.
The magnet device according to claim 1 or 2, wherein the magnet device is set to have a large size of about 06 mm.