JPS632757B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rubber material suitable for removing and cleaning toner containing a trace amount of pigment such as carbon black remaining on the surface of a transfer drum of an electrophotographic copying machine, etc. This invention relates to a molding device for manufactured blades.

(Prior Art) Conventionally, as shown in FIG. 1, a rubber blade (hereinafter simply referred to as a blade) used for the above-mentioned purpose is a plate-shaped blade 1 having a rectangular longitudinal section and a predetermined size, and is attached to a rotating transfer drum. 2. It is attached and used by being pressed against a surface.

In order to completely remove pigments such as ultrafine particles (3 μm) of carbon black remaining on the surface of the transfer drum 2, the blade edge 1a slidingly contacts the surface of the transfer drum 2.
(5/1000 or higher), Blade Edge 1a
Extremely strict dimensional accuracy and surface accuracy are required, such as small ridge line roughness (10 μm or less) and no undulations in the ridge line of the blade edge 1a (in other words, excellent linearity).

Further, since the blade 1 is used with its blade edge 1a pressed against and in sliding contact with the surface of the transfer drum 2, it is formed of a material such as urethane rubber that has excellent wear resistance.

Therefore, various methods have been proposed to manufacture blades that satisfy such strict required characteristics, but no satisfactory method has yet been found.

(Problems to be Solved by the Invention) For example, the following methods are known, but each has many drawbacks when used in mass production.

The first method is to cast urethane rubber using a precision mold. With this method, it is difficult to manufacture a precision mold with a high-precision edge, and the desired blade cannot be obtained, and even if it can be manufactured, it is expensive, and the resulting blade is also expensive and the manufacturing efficiency is poor. Not suitable for mass production.

The second method is to cool and harden a preformed plate-shaped urethane rubber sheet, and then cut it with a cutting blade or the like without applying distortion in this state. In this method, if a rubber sheet that exhibits elasticity at room temperature is pressed down and cut, the elastic body will be distorted, making it impossible to obtain a cut surface and dimensional accuracy that satisfy the above-mentioned strict required properties. Although this method has been proposed in view of the above, the apparatus is complicated, it cannot be said to be simple, and, like the first method, it is not suitable as a method for mass production.

The present invention was devised in view of the above circumstances, and it is an object of the present invention to provide a molding device that can easily manufacture a blade that satisfies the above-mentioned strict required characteristics at room temperature.

(Means for Solving the Problems) The present invention provides a drum having an axial center and around which a rectangular rubber sheet having a predetermined blade thickness is wound and fixed on the outer circumferential surface, and A rubber blade forming device comprising: a cutting blade that contacts a rubber sheet and forms a slit in the drum circumferential direction of the rubber sheet leaving both ends of the drum circumferential direction in order to form a predetermined blade width; At least one groove is provided in the entire axial width of the surface and in the circumferential direction for fixing both ends of the rubber sheet in one direction, and a plurality of cutting blades are provided at predetermined intervals in the circumferential direction of the outer peripheral surface of the drum excluding the recess. Summary of a rubber blade molding device, in which an relief groove is provided, and the bottom surface of the recess is formed at a position where both ends of the rubber sheet fixed to the upper part are not cut through by the cutting blade in the thickness direction. shall be.

(Example) Hereinafter, the molding apparatus of the present invention will be explained in detail.

FIG. 2 shows an embodiment of the molding apparatus of the present invention, which includes a drum 14 having a shaft core 12 and around which a rectangular rubber sheet 32 having a predetermined blade thickness is wrapped and fixed; a cutting blade 22 that contacts the rubber sheet 32 at right angles to the axial direction of the drum 14 and forms a slit 322 in that direction leaving both ends of the rubber sheet 32 in the drum circumferential direction to form a predetermined blade width; In particular, a recess 142 for fixing both ends 321, 321 of one rubber sheet 32 is provided in the entire axial width of the outer peripheral surface of the drum 14 in the circumferential direction, and further, the outer periphery of the drum 14 excluding the recess 142 A plurality of cutting blade relief grooves 141 are provided at predetermined intervals in the circumferential direction of the surface, and the bottom surface 142a of the recessed portion is provided with both ends 321, 3 of the rubber sheet 32 fixed to the upper portion.
21 is formed in the thickness direction at a position that is not cut through by the cutting blade 22.

Incidentally, the side surface 142b of the recessed portion 142 in the radial cross section of the drum 14 may be formed into a tapered shape or an inclined surface so that the both ends 321, 321 of the rubber sheet 32 are tightly fixed.

Further, as the cutting blade 22, a commonly known hard cutter blade or the like having a thin wall and a sharp cutting edge angle is used.
As the cross-sectional shape in the four-axis direction, a semicircular arc shape, a concave groove shape, a V-groove shape, etc. are used as appropriate.

Furthermore, the drum 14 and the cutting blade 22 are configured to be rotatable relative to each other, or the drum 14 is usually rotatable due to the design and workability of the device, and the cutting blade 22 is rotated in the axial direction of the drum 14. It is configured to be able to move forward and backward in a direction perpendicular to .

Next, a method for forming a blade using the forming apparatus of the present invention will be explained.

First, a rubber sheet having a predetermined thickness is formed by centrifugal molding or the like.

That is, by casting a predetermined amount of liquid urethane rubber or the like on the inner circumferential surface of a cylindrical drum so as to have a predetermined blade thickness, and then rotating the drum at high speed, a rubber sheet of urethane rubber or the like having a uniform thickness is produced. is formed by centrifugal molding. In particular, centrifugal molding is convenient for forming products with uniform thickness.

According to the centrifugal molding method as described above, the surface of the rubber sheet that is not in contact with the inner peripheral surface of the drum is formed into a mirror-like surface (a high-precision surface with a JIS surface roughness of 5S or more).

The rubber sheet formed in this way is
It is wound and fixed on the outer peripheral surface of the drum of a molding device as shown in the figure.

At this time, the rubber sheet 32 has both ends in one direction aligned with the circumferential direction of the drum 14, and
It is wrapped with a tension of about 0.5 to 5%,
Both ends 321, 321 are connected to the drum recess 142.
It is fixed with adhesive tape etc.

Next, the drum 14 is rotated, and in this state, the cutting blade 22 is advanced perpendicularly to the axial direction of the drum 14, making contact with the rubber sheet 32 and cutting the rubber sheet in a predetermined direction, leaving both ends 321, 321. A slit 322 is formed to form a blade width of 1, and then the cutting blade 22 is retreated. Thereafter, this operation is repeated to form a plurality of slits 322 of a predetermined width in the width direction of the rubber sheet 32. Then, the rubber sheet 32 with the slits 322 formed thereon is removed from the drum 14 (see FIG. 3), and both ends 321, 321 of the rubber sheet 32 are cut off in the width direction to form a predetermined blade length. , obtain a blade 42 of predetermined dimensions.

The tension value applied to the rubber sheet 32 when wrapping and fixing the rubber sheet 32 on the outer peripheral surface of the drum 14 is within this range.
slit 322 without giving excessive distortion to 2.
This is because it is easy to form and is preferable for obtaining highly accurate dimensional stability and cutting surfaces.In this case, both ends 321, 321 of the rubber sheet 32 serve as attachment parts when fixing, and the slits 322 This formation also helps to prevent each blade from coming apart.

On the other hand, in the molding apparatus of the present invention, the drum 1
It is also possible to provide a plurality of recesses 142 in the drum 14 in the circumferential direction as shown in FIG. Since the blades 42 can be wrapped and fixed, a large number of blades 42 can be molded at once with less variation, further improving manufacturing efficiency.

Further, the outer peripheral surface of the drum 14 excluding the recess 142 is
Mirror-like surface (a high-precision surface with a JIS surface roughness of 5S or higher, specifically a hard chrome plated surface, etc.)
When the surface of the rubber sheet 32 is formed into a mirror shape, the adhesion force with the surface of the rubber sheet 32 to be wrapped increases (further increases if the surface of the rubber sheet is also a mirror-like surface), and the fixation of the rubber sheet 32 becomes stronger.

As explained above, the blade molded according to the present invention has an excellent effect of removing and cleaning toner containing pigments such as carbon black that remains in trace amounts on the surface of a transfer drum of an electrophotographic copying machine, etc. It has advantages such as improved durability due to its excellent abrasion resistance.

(Effects of the Invention) As explained in detail above, according to the molding apparatus of the present invention, the elastic body (rubber sheet) can be cut with high precision (no radius on the edges) without causing almost any distortion at room temperature. This makes it possible to easily manufacture blades with low edge ridge roughness and excellent edge ridge straightness with high efficiency and with little variation, making it possible to mass-produce blades and thereby significantly reducing costs. This has the practical effect of reducing the amount of water used.

[Brief explanation of the drawing]

Fig. 1 is a schematic vertical cross-sectional view showing the blade mounting structure, and Fig. 2 is an embodiment of the molding apparatus of the present invention. FIG. 3 is a front view of a rubber sheet in which slits are formed to explain the present invention, and FIG. 4 is a cross-sectional view of the rubber sheet after being wrapped and fixed. FIG. It is a perspective view, and FIG. 5 is a sectional view corresponding to FIG. 2C showing another embodiment of the molding apparatus of the present invention. 12... Axis core, 14... Drum, 141... Cutting blade relief groove, 142... Recessed portion, 142a... Recessed portion bottom surface, 14
2b... Side face of recess, 22... Cutting blade, 32... Rubber sheet, 321... Rubber sheet end, 322... Slit, 42... Blade.

Claims (1)

[Scope of Claims] 1. A drum having an axial core and around which a rectangular rubber sheet having a predetermined blade thickness is wound and fixed on its outer peripheral surface; A rubber blade forming device comprising: a cutting blade that forms a slit in the drum circumferential direction, leaving both ends of the drum circumferential direction, to form a slit to form a predetermined blade width; Providing at least one recess in the circumferential direction for fixing both ends in one direction of the rubber sheet, and further providing a plurality of cutting blade relief grooves at predetermined intervals in the circumferential direction of the outer peripheral surface of the drum excluding the recess; A rubber blade molding device, characterized in that the bottom surface of the recess is formed at a position where both ends of the rubber sheet fixed to the upper part are not cut through by the cutting blade in the thickness direction.