JPH0316262Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" This invention relates to a shaft for magnet rolls.
More specifically, the present invention relates to a novel shaft for a magnet roll that allows easy pole alignment, high productivity, and small positional deviation in the angle between poles, thereby improving fluctuations in copying characteristics. The magnet roll shaft of the present invention is used in developing devices and cleaning devices of electronic copying machines, facsimile printers, and the like.

"Prior Art and Problems" Conventionally, this type of shaft for a magnet roll has a magnet adhesive part 1 with a polygonal cross section and an earth stopper E-ring insertion groove 2, as shown in FIG.
and a pole position regulating section 3. 4 is a chamfered portion for regulating the pole position. Around the magnetic adhesive part 1 of the shaft, as shown in FIG.
Magnets 5a to 5 made by extruding resin or rubber magnets for the number of poles into the same shape or, in many cases, into an irregular shape.
d for the required number of poles, and furthermore, although not shown, attach it to the magnet roll support of a developing machine such as a copying machine, and attach a sleeve made of non-magnetic material such as aluminum or SUS304 to the outer periphery of the magnet roll. Used for transporting developer, etc.

However, in the case of the above-mentioned magnet roll, since the magnet bonding part is polygonal, deflection (bending) is likely to occur, which causes variation in the longitudinal direction of the magnetic force, and also A time lag occurs, and the position where the peak magnetic field of each pole appears, that is, the angle between the poles, and the surface magnetic field strength of the poles fluctuate, and as a result, the copying characteristics deteriorate. Furthermore, bonding work is required for the number of magnetic poles, which increases manufacturing costs.

In order to solve this problem, if a shaft with a circular cross section is used for the magnet bonding part, the above runout will be reduced, but it will be difficult to align the poles of the magnet, and in the case of a rotating sleeve type magnet roll, the end part Secondary processing is required to regulate the pole position, which not only reduces productivity but also
The above-mentioned secondary processing is usually performed by cutting, and therefore has poor accuracy.

Furthermore, a structure in which short cylindrical magnets are added has been proposed, but in this case as well, it is not only difficult to align the poles, but also because the magnets are magnetized after being attached to the shaft. Even if they match, it is difficult to avoid variations in the magnetic force in the longitudinal direction. In addition, the effort required to insert the earth stopper into the earth stopper E-ring insertion groove 2 shown in FIG. 1 is also a factor that hinders productivity improvement.

"Means for Solving the Problems" In view of the above circumstances, the present inventors have arrived at the present invention as a result of intensive research to solve the above problems.

That is, the present invention provides a magnet roll in which an irregularly shaped part is provided at the end of a magnet mounting part having a circular cross section, and a magnet longitudinal positioning/earth stopper is provided protrudingly at the boundary between the magnet mounting part and the irregularly shaped part. The contents include a shaft for use.

The present invention will be described based on drawings showing embodiments.

FIG. 3 is a perspective view of the shaft of the present invention, and FIG. 4 is a side view of the shaft with a cylindrical magnet bonded to it. In the shaft of the present invention, an irregularly shaped part 12 is provided at the end of a magnet mounting part 11 having a circular cross section.
is installed protrudingly. 14 is a chamfered portion, and 15 is a cylindrical magnet.

The shaft of the present invention is made of synthetic resin, metal, or other known materials. As the above synthetic resin,
Engineering plastics such as polycarbonate, polyphenylene sulfide, polysulfone, and polyamide; thermosetting resins such as epoxy and phenol are preferably used, and reinforcing agents and other additives may be added as necessary. As the metal, iron, aluminum, etc. are suitable.

As shown in FIG.
5 and protrudes so as to be higher than the outer peripheral surface of the shaft adhesive portion. It goes without saying that the magnet longitudinal positioning/earth stopper referred to in the present invention serves only as a magnet longitudinal positioning when grounding is not required.

As described above, the cylindrical magnet 15 is attached to the magnet mounting portion 11 of the shaft, for example, via an adhesive or by welding. Insertion of the cylindrical magnet 15 fixes the irregularly shaped portion 12 in a predetermined position while reading the pole position of the cylindrical magnet. The cylindrical magnet 15 is made of a known resin or rubber, and the magnetic powder is a known magnetic powder. It may be either isotropic or anisotropic. The cylindrical magnets 15 include, for example, those magnetized and extruded to have a substantially O-shaped cross section, and those magnetized and extruded to have a substantially C-shaped cross section, which are used by placing two opposing magnets.

Known adhesives are used as the adhesive, such as thermoplastic resin adhesives such as acetic acid vinyl chloride copolymer, acrylic, polystyrene, and polyvinyl ether cyanoacrylate; thermosetting resin adhesives such as phenol and epoxy; Rubber adhesives such as butadiene rubber and nitrile rubber can be used, but due to the need to adhere after inserting the shaft,
It does not harden in air, and if the air is cut off, it will harden at room temperature.
Anaerobic adhesives (eg, tetraethylene glycol dimethacrylate) that cure in ~10 minutes are suitable.

FIG. 5 shows another embodiment of the shaft of the present invention, in which a deformed part 12 is provided at the end of a magnet mounting part 11 having a circular cross section.
A magnet longitudinal positioning/earth stopper 13 is provided protrudingly between and the irregularly shaped portion 12. 14
is the chamfered part. FIG. 6 is a side view of the cylindrical magnet 15 attached to the magnet attachment portion 11 of the shaft.

FIG. 7 shows still another embodiment of the shaft of the present invention, in which an integrally molded body 16 of a magnet longitudinal alignment/earth stopper 13 and a deformed part 12 is joined to the end of a magnet mounting part 11 having a circular cross section. has been done. In this case, the magnet mounting part 11 and
Magnet longitudinal alignment and earth stopper 1
3 and the irregularly shaped portion 12 may be made of different materials. The joint portion of the magnet mounting portion 11 with the integral molded body 16 can be knurled or the like to increase the joint strength. When an adhesive is used, the adhesive described above is used.

Figures 8 to 10 show the magnet longitudinal alignment/earth stopper 13 and the irregularly shaped part 1, respectively.
2 shows an embodiment of an integrally molded body 16 with 2.

"Function/Effect" As mentioned above, the present invention has a circular cross section, so there is little deflection and the insertion work is high, and the cylindrical magnet can be inserted into the shaft (magnet attachment part) with a circular cross section while reading the pole position. Since the irregularly shaped part can be fixed in a predetermined position by inserting the ground stopper, there are advantages such as there is almost no variation in the magnetic force in the longitudinal direction, the trouble of attaching an earth stopper to the groove is eliminated, and the work process is simplified. However, its usefulness is great.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional magnet roll shaft, Fig. 2 is a side view of the conventional shaft shown in Fig. 1 with a magnet attached, and Fig. 3 is a magnet roll shaft of the present invention. FIG. 4 is a side view of the shaft shown in FIG. 3 with a magnet attached to it, FIG. 5 is a perspective view showing another embodiment of the shaft of the present invention, and FIG. 6 is a side view of the shaft of FIG. FIG. 7 is a perspective view showing still another embodiment of the shaft of the present invention, and FIGS. 8 to 10 show the longitudinal positioning of the magnet used in the present invention. FIG. 2 is a perspective view showing an embodiment of an integrally molded body of a doubling-earth stopper and a deformed part. 11... Magnet attachment part, 12... Unusual part,
13... Magnet longitudinal alignment/earth stopper, 14... Chamfered portion, 15... Cylindrical magnet, 16... Integrated molded body of magnet longitudinal alignment/earth stopper and irregularly shaped part.

Claims (1)

[Claims for Utility Model Registration] 1. An irregularly shaped part is provided at the end of a magnet mounting part having a circular cross section, and a magnet longitudinal positioning/earth stopper is protrudingly provided at the boundary between the magnet mounting part and the irregularly shaped part. Shaft for magnet roll. 2. The shaft according to claim 1, which is a registered utility model, in which an integrally molded body of a magnet longitudinal positioning/earth stopper and a deformed part is attached to the end of the magnet attachment part.