JPH0528018Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a mold for forming a cleaning blade that removes toner remaining on a photosensitive drum of an electrophotographic copying machine or the like.

[Conventional technology]

An electrophotographic copying machine is equipped with a photosensitive drum having a photoconductor surface layer, and the outer circumferential surface of the photosensitive drum is uniformly charged, and then the outer circumferential surface is exposed to light through the image of the object to be copied. Copying is performed by forming an electrostatic latent image on the outer circumferential surface, applying toner to the electrostatic latent image to form a toner image, and transferring this to copy paper or the like. Since toner remains on the outer peripheral surface of the photosensitive drum after the copying, it is necessary to remove this residual charged toner, and this removal is performed using a cleaning blade. This cleaning blade is shown in FIG. In the figure, reference numeral 1 denotes a cleaning blade, and a thick plate-shaped blade member 3 made of soft urethane resin is attached to the tip of a metal plate-shaped holding material 2 so that the length direction of the plate-shaped holding material 2 is aligned. The tip portion is embedded in the blade member 3. This cleaning blade 1, as shown in FIG.
The blade side of the blade member 3 is pressed against the photosensitive drum 4 rotating in the direction of the arrow, and the lower edge portion 5 is brought into sliding contact with the photosensitive drum 4 to scrape off residual toner (not shown). As shown in FIG. 6, this type of cleaning blade 1 generally uses a molding die 6 that is divided into upper and lower halves and has a cavity for casting a blade member 3 made of soft urethane resin. By inserting the tip of the plate-shaped holding material 2 into the cavity of the mold, injecting a soft urethane resin material into the cavity in this state and molding it, then removing the mold and cutting at the chain line a. Manufactured. The blade member 3
It is required that the edge portion 5 formed by the cutting described above be in a linear state with high precision along the longitudinal direction so that it can come into uniform contact with the photosensitive drum 4. Therefore, prior to the above-mentioned molding, a glass material 7 is provided in the cavity of the molding die 6 corresponding to the photosensitive drum pressing side surface 3a of the blade member 3, and the surface of the glass material 7 is transferred to form the blade member 3. It has been proposed to form the photosensitive drum pressing side surface 3a smooth.

[Problem that the invention attempts to solve]

However, as described above, when the glass material 7 is used, the thermal expansion coefficients of the glass material 7 and the molding die 6 are different, so as shown in FIG. Therefore, there is a problem that the position of the glass material shifts between the room temperature and the high temperature, resulting in poor dimensional accuracy of the cleaning blade 1. In addition, the glass material 7 cannot be fixed with bolts, nuts, etc., and can only be placed on the lower side of the molding die 6 because it is simply placed thereon. Therefore, there is also the problem that objects are easily dropped onto the glass material 7 during the molding operation, or the plate-like holding material 2 is easily hit and scratched when the plate-like holding material 2 is attached. Furthermore, the glass material 7 is difficult to release from the urethane resin material, and therefore requires pretreatment such as applying a mold release agent to the surface of the glass material 7, making the work complicated. In particular, since the thickness of the glass material 7 is not uniform, there is a major problem in that it is difficult to achieve parallelism (flatness) of the blade member surface with respect to the plate-shaped holding material.

This invention was devised in view of the above circumstances, and the purpose is to provide a mold for molding cleaning blades that can mold cleaning blades with high precision, has excellent durability, and facilitates molding work. .

[Means for solving problems]

In order to achieve the above object, the mold for molding the cleaning blade of this invention has a mirror-finished surface with a surface roughness of 0.2 μm on the ceiling part of the molding space corresponding to the surface of the plate-shaped blade member in the cleaning blade. It has a structure in which a plate-shaped corrosion-resistant rustless steel as shown below is fixed.

[Effect]

In other words, the mold for forming this cleaning blade does not use a glass material as the smooth surface state transfer part as in conventional examples, but uses a special material whose surface is finished to a mirror finish with a surface roughness of 0.2 μm or less. Made of corrosion-resistant stainless steel. Therefore, the surface of the blade member (the surface that faces the photosensitive drum during use)
It becomes possible to improve the flatness of the blade member surface while maintaining good smoothness, and it also becomes highly durable without corrosion or rust even after long-term use. In particular, this idea
The above-mentioned corrosion-resistant stainless steel, which is easier to form with a uniform overall thickness than glass material, is used, and its surface is roughened.
By finishing it to a mirror surface of 0.2 μm or less, it is possible to transfer the same surface smoothness to the surface of the blade member as when using a glass material, and it also gives the blade member excellent flatness that cannot be achieved when using a glass member. This is a major feature. Further, since the coefficient of thermal expansion of the corrosion-resistant stainless steel is almost the same as that of other parts of the mold, no displacement occurs due to heating, and the dimensional accuracy of the cleaning blade is improved. Furthermore, since it can be fixed with bolts, nuts, etc., it can be fixed to the ceiling of the molding space in the mold, making it less likely to be damaged.

Next, this invention will be explained in detail based on examples.

〔Example〕

FIG. 1 shows an embodiment of this invention. That is, in the figure, 11 is a mold made of a general-purpose steel material that is divided into upper and lower halves, and a recess 12 is provided downward on the lower surface of the upper mold 11a. A surface forming member 1 made of 13% Cr stainless steel (corrosion-resistant and rustless steel) whose lower surface is mirror-finished (surface roughness of 0.2 μm or less) is placed on the ceiling surface of the recess 12.
3 is fixed with a bolt 14. Also,
Lower mold 11b corresponding to the surface forming member 13
A recess 15 is provided in the portion, and a cavity for molding the blade member 16 is formed by this recess 15 and the lower surface of the surface forming member 13 attached to the upper mold 11a. Reference numeral 17 denotes a holding material mounting portion having an L-shaped vertical cross section, which is formed to communicate with the recessed portion 15, and is connected to the tip portion 18a of the holding material 18.
The holding member 18 can be attached with the holding member 18 positioned at one end side within the cavity. Reference numeral 19 denotes a closing member disposed on the other end side of the cavity, and is fixed to the lower mold 11b with bolts 20.

When manufacturing a cleaning blade using the mold 11 described above, first, the retaining material 18 is attached to the retaining material attachment part 17 of the lower mold 11b, and in this state, the upper mold is attached to the upper surface of the lower mold 11b. 11a are combined and the holding material 18 is fixed. Next, liquid urethane resin material is injected into the cavity formed by the lower surface of the surface forming member 13 attached to the upper mold 11a and the recess 15 of the lower mold 11b through a gate (not shown). By curing this, the blade member 16 is formed integrally with the holding material 18. Next, the obtained molded product is demolded from the mold 11, and as shown in FIG. disconnect. As a result, a cleaning blade 21 is obtained. This cleaning blade 21 has a surface 2 of the blade member 16.
1a is transferred and formed on a smooth surface by the mirror surface of the surface forming member 13, and the cut surface 21b is also cut with a sharp cutting edge, so that it has a smooth surface that is almost the same as the surface 21a. Therefore, when the edge portion 22 of the cleaning blade 21 is brought into pressure contact with the outer circumferential surface of the rotating photosensitive drum (see FIG. 5), the outer circumferential surface is evenly pressed and good cleaning can be performed without unevenness. become. Furthermore, since the surface forming member 13 is made of 13% Cr stainless steel, corrosion and rust are less likely to occur. Therefore, the cleaning blade 21 as described above can be manufactured over a long period of time. Note that the surface roughness of the surface forming member 13 is 0.2 μm or less,
More preferably, it is 0.05 μm or less. In addition, the inclination angle of the surface forming member 13 with respect to the holding material 18 (this angle is a measure of the parallelism (flatness) of the surface of the plate-shaped blade member 16 with respect to the holding material 18, and the best inclination angle is zero) is as follows. It is desirable to set the angle so that the maximum gap c shown in FIG. 3 is 10 μm or less, more preferably 5 μm or less. When a glass material is used for the surface forming member 13, since the thickness of the glass material cannot be formed uniformly, the thickness of the surface forming member 13 in the length direction becomes non-uniform in FIG. The gap c becomes larger.

In this way, this mold 11 has a surface forming member 1
3. Instead of using glass material, we use a special corrosion-resistant stainless steel with an extremely smooth, mirror-finished surface. Therefore, the smoothness of the surface 21a of the blade member 16 can be greatly improved, and a good edge portion 22 can be formed, and even if used for a long period of time, no corrosion or rust will occur, resulting in excellent durability. ing. In addition, the mold 11 and the surface forming member 13
Since the coefficient of thermal expansion is almost the same as that of the cleaning blade 21, the cleaning blade 21 with good dimensional accuracy can be manufactured without causing any displacement of the surface forming member 13 even at high temperatures. Furthermore, the surface forming member 13 is a bolt,
Since it can be fixed with a nut or the like, it can be placed even on the upper side of the mold 6, and is therefore less likely to be damaged. Furthermore, since the blade member 16 does not adhere to the mold 11, the pretreatment process for removal can be simplified.

[Effect of idea]

As described above, the mold for molding the cleaning blade of this invention has a mirror-finished surface on the part corresponding to the surface of the plate-like blade member of the cleaning blade in the molding space, and can be formed into a uniform layer over the entire surface. Constructed of corrosion-resistant stainless steel.
Therefore, it has good dimensional accuracy and excellent durability. In particular, the above-mentioned corrosion-resistant stainless steel can be finished with a uniform thickness in the length direction compared to glass materials.
It can be arranged with good parallelism to the holding member, thereby making it possible to make the flatness of the plate-shaped blade member highly accurate. Furthermore, the above-mentioned corrosion-resistant stainless steel can be placed on the ceiling side of the space of the mold and fixed with bolts or the like. Therefore, the surface of the corrosion-resistant stainless steel is less likely to be damaged by falling molding members, etc., and the corrosion-resistant stainless steel does not get in the way, making the molding work easier.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view illustrating a method of manufacturing a cleaning blade using an embodiment of this invention, Fig. 2 is an explanatory view of the cleaning blade obtained thereby, and Fig. 3 is a holding material and surface formation. FIG. 4 is a perspective view of a conventional cleaning blade, FIG. 5 is an explanatory view of its use, and FIG. 6 is a longitudinal sectional view illustrating its manufacturing method. 11...Mold, 13...Surface forming member, 16...
...Blade member, 21...Cleaning blade.

Claims (1)

[Scope of utility model registration request] A feature of the cleaning blade is that a plate-shaped corrosion-resistant stainless steel with a mirror-finished surface and a surface roughness of 0.2 μm or less is fixed to the ceiling of the molding space corresponding to the surface of the plate-shaped blade member of the cleaning blade. A mold for molding a cleaning blade.