JPH0347291Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a magnet roll used to convey dry developer in image forming apparatuses such as electrophotographic copiers, facsimile machines, and printers. be.

(Prior Art) As a conveyance means for dry development such as magnetic brush development and magnetic brush cleaning in an electrophotographic copying machine, a cylindrical magnet having a plurality of magnetic poles on the surface of a non-magnetic sleeve and the inside thereof is used. Magnet rolls configured to rotate relative to each other are commonly used.

3 to 5 are longitudinal sectional front views of conventionally used magnet rolls.

In Fig. 3, 1 is a cylindrical magnet such as a ferrite magnet, 2 is a pipe-shaped central shaft made of stainless steel, aluminum, etc., and the assembly method is as follows:
Insert the center shaft 2 into the magnet 1 and the center shaft 2 by integrally molding with adhesive 4 or injection molding.
For example, with the outer peripheral surface of the magnet 1 as a reference, both ends of the central shaft 2 are subjected to a spigot process, and the shaft parts 3a and 3b are respectively inserted into the spigot parts and fixed by adhesive 4 or press fitting. Here, external polishing is performed without spigot machining. Alternatively, you can omit external research when conducting injections.

Furthermore, FIGS. 4 and 5 show another conventional example (an example in which the outer diameter of the magnet is large (40 mmφ or more)), in which the magnet 1 has a ribbed pipe-shaped center shaft 2'.
is inserted, the magnet 1 and the central shaft 2' are fixed with adhesive 4, the shaft 3 is press-fitted into one end of the central shaft 2', and the flange 5 is fixed with adhesive 4 to the other end of the central shaft 2'. A bearing 6 is press-fitted into the inside of the flange 5, and the shaft portion 8 of the flange 7 fixed to one end of the sleeve 9 is inserted into the bearing 6, so that the sleeve 9 and the magnet 1 can rotate relative to each other.

(Problems to be solved by the invention) In the conventional magnet roll, as mentioned above, the end of the pipe-shaped central shaft is subjected to, for example, a spigot process, and the shaft part or flange is inserted into the spigot part.
Although they were fixed with adhesive or the like, there was a problem in that spacers and special shafts were required, which increased the manufacturing cost of the magnet roll.

(Means for Solving the Problems) In order to solve the above problems, the present invention fixes a cylindrical magnet to a pipe-shaped central shaft, and provides supporting members on the inner surfaces of the curling parts at both ends of the pipe-shaped central shaft. is fixed.

(Function) Since support members such as support shafts and bearings are press-fitted and fixed to the inner surface of the curled portions at both ends of the pipe-shaped central shaft, the bonding strength will not decrease even after long-term use.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. FIG. 1 is a longitudinal sectional front view of the magnet roll of the present invention. In the figure, both ends of a pipe-shaped central shaft 2 are curled to provide portions into which shafts 3 and 3' are inserted. The inner peripheral surface of the cylindrical magnet 1 is fixed to the outer peripheral surface of the pipe-shaped central shaft 2 with an adhesive. The surface of the cylindrical magnet 1 is machined to a predetermined size, and both end faces of the pipe-shaped central shaft 2 are machined based on the surface to achieve coaxiality. At this point, external grinding may be performed using the central shaft as a reference, or external grinding may not be necessary in the case of in-jet extension. Next, the shafts 3 and 3' finished to predetermined dimensions are fixed to the curled portions by press fitting or the like.

Further, as shown in FIG. 2, a bearing may be press-fitted in place of the shaft 3' of FIG. 1, and the shaft portion 8 of the flange 7 shown in FIG. 4 may be supported by the bearing.

(Effects of the invention) As described above, the magnet roll of the invention curls both ends of the pipe-shaped central shaft, and fixes the support shaft or bearing to the curled portion by press-fitting, etc. It is unnecessary and can be produced at low cost.

[Brief explanation of the drawing]

1 and 2 are vertical sectional front views of the magnet roll of the present invention, FIGS. 3 and 4 are vertical sectional front views of the conventional magnet roll, and FIG. 5 is a vertical sectional front view of the magnet roll of the present invention. FIG. 1... Cylindrical magnet, 2, 2'... Pipe-shaped central shaft, 3, 3', 3a, 3b... Shaft, 5... Flange, 9... Sleeve.

Claims (1)

[Scope of utility model registration request] A magnet roll characterized in that a cylindrical magnet is fixed to a pipe-shaped central shaft having curling parts at both ends, and a support member is fixed to the inner surface of the curling parts at both ends of the pipe-shaped central shaft.