JP2010110949A - Mold for oa blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold for OA blade, designed to efficiently produce by preventing the occurrence of not only a short shot but flash. <P>SOLUTION: The mold used for producing the OA blade is provided with an elastic member on a lengthy plate in a longitudinal direction. Roughening processing is performed on the surface of the mold on which the plate is set, and functioned as a gas letting-out mechanism for discharging the unnecessary gas accumulated in a cavity when the OA blade is produced. Therefore, occurrence of the short shot during production is securely prevented, and a yield of a product is enhanced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a mold used for manufacturing an OA blade in which an elastic member such as a rubber material is bonded to one side of a hard plate made of a long thin metal plate or the like.

  In electrophotographic or electrostatic recording type image forming apparatuses such as copying machines, facsimiles, and printers (hereinafter collectively referred to as “OA apparatuses”), a developer is carried on the outer periphery of a developing roller and rotated. OA blades such as a developing blade for regulating the amount of developer supplied by the developing roller, a cleaning blade for cleaning the photosensitive drum or belt, and a transfer blade are used.

  As such an OA blade, a rubber member having a sufficient flexibility to form a gap through which the developer passes and characteristics necessary for triboelectrically charging the developer, such as a long metal The form of being bonded on the plate is widely adopted.

  For such an OA blade that regulates the amount of developer, for example, a metal plate pre-applied with an adhesive is set at a predetermined position in a mold, and the material is molded using a transfer molding method or an injection molding method. A manufacturing method is employed in which a metal member such as silicone rubber is bonded to a metal plate in a mold.

For example, as shown in Patent Document 1, the mold is composed of an upper mold and a lower mold. The upper die or the lower die is provided with a cavity having a shape corresponding to the rubber member to be attached to the metal plate. By inserting (setting) the metal plate into a predetermined position of the cavity and pouring and curing the material of the rubber member, an OA blade provided with the rubber member along the longitudinal direction of the long metal plate can be manufactured. .
JP 2006-315185 A

  By the way, as described above, the blade for OA fulfills functions of thickness regulation and frictional charging by bringing a rubber member or the like attached to a metal plate into contact with the developer. Therefore, there is an extremely high demand for manufacturing a rubber member having a properly formed edge level, that is, a sharp shape. Furthermore, the OA blade as described above is often changed into a complicated shape according to various requirements on the apparatus side.

  FIG. 7 is an enlarged view showing a part of the rubber member GM attached on the metal plate MP of the OA blade BL. FIG. 7A shows a state where the rubber member GM pasted on the metal plate MP is not filled at the end of the OA blade BL and a short shot portion (hereinafter simply referred to as a short) SH is generated. It is a perspective view showing typically. FIG.7 (b) is a top view about Fig.7 (a).

  As shown in FIGS. 7A and 7B, at the end of the cavity, gas mixed at the contact surface (boundary surface) with the metal plate MP (mainly air remaining without being discharged outside). In some cases, the rubber member to be filled may cause a short SH due to the stagnation. Further, as in the case of the OA blade BL shown in FIG. 7C, there may be a more complicated shape having a notch HG at the end depending on the requirement on the apparatus side. In such a case, a short SH occurs in more places. When such a short SH occurs, the manufactured OA blade becomes defective. As a result, the yield of the product is lowered, so that an appropriate countermeasure for preventing a short circuit is desired.

  Therefore, conventionally, as shown in FIG. 8, for example, in the conventional mold 100, measures such as installing a gas escape portion (gas vent portion) GV in a portion where short SH is likely to occur are generally taken. It was. However, the installation of such a gas escape portion not only complicates the mold structure, but also introduces a new problem that burrs are likely to occur.

  Therefore, a main object of the present invention is to propose a mold for blades for OA designed so that not only a short circuit but also generation of burrs can be suppressed and manufactured efficiently.

  The above object is a mold used for manufacturing an OA blade in which an elastic member is provided along a longitudinal direction on a long plate, and the surface on which the plate is set is roughened. This can be achieved by an OA blade mold characterized by the above.

  Moreover, it is desirable that the Ra value for the mold surface roughness is 0.10 to 0.30 μm. If the surface of the mold is roughened so as to satisfy any one of these numerical values, the blade for OA can be manufactured while more surely removing unnecessary gas staying in the cavity.

  Further, the mold is composed of an upper mold and a lower mold, and a cavity corresponding to the shape of the elastic member is formed in the upper mold or the lower mold, and the plate is set. It is possible to adopt a structure in which the rough surface processing is applied to the surface of the mold on which the cavity is formed.

  Further, it is desirable that the mold further includes a vacuum drawing structure for vacuuming the periphery of the cavity. Thereby, the occurrence of a short circuit can be reliably prevented, and the material filling rate can be further improved.

  According to the present invention, since the surface of the mold on which the plate is set is roughened, the gas that discharges unnecessary gas generated from the air or material that has accumulated in the cavity when the OA blade is manufactured. It can function as an escape mechanism. Therefore, it is possible to reliably prevent the occurrence of a short circuit during manufacturing and improve the product yield. Further, by forming such rough surface processing finely, only gas can be released while suppressing the passage of the material. Therefore, not only a short circuit but also the generation of burrs can be suppressed, and an OA blade can be manufactured efficiently.

Hereinafter, an embodiment according to the present invention will be described in detail with reference to the drawings. In the following embodiments, a developing blade will be described as an example, but applicable OA blades are not limited thereto.
FIG. 1 is a schematic view showing a state when an OA blade manufactured by a mold according to the present embodiment is attached to an OA apparatus. FIG. 2 is a plan view showing a structural example of an OA blade manufactured by the mold according to the present embodiment.

  The OA blade 1 includes a metal plate 2 as a thin and long plate, and a rubber member 3 as an elastic member disposed on a part of one surface 2a thereof. As such a rubber member 3, for example, a thermosetting rubber material such as two-component curable polyurethane, fluororubber, chloroprene rubber, millable silicone, and liquid silicone rubber can be suitably used, but the productivity is excellent. In view of this, it is preferable to use liquid silicone rubber.

  The metal plate 2 can be formed of, for example, stainless steel (SUS) or phosphor bronze. The rubber member 3 is bonded and fixed along the longitudinal direction of the metal plate 2 with an adhesive or a primer. Blank areas BA are set on both sides of the OA blade 1, and a rubber member 3 is bonded to a central portion between the blank areas BA.

  As shown in FIG. 1, the OA blade 1 is arranged in a posture in contact with the circumferential surface of the rotating developing roller 100 or in a posture having a slight gap with the circumferential surface, and the development on the developing roller circumferential surface 100 a is performed. It functions to regulate the layer thickness of the agent 101.

  As shown in FIG. 2, the outer shape of the rubber member 3 to be attached to the OA blade 1 is appropriately provided with a protruding portion that protrudes outward or an indented recess on the inside as required. It is done. That is, the OA blade 1 shown in FIG. 2 has notches HG at both ends of the rubber member 3, and protrusions 3TA-1 and 3TA-2 projecting upward at both ends. Here, the illustrated structure is a protruding portion 3TA-1 formed in accordance with a protruding portion for a gate which is arranged to protrude to the inner side (non-contact side) on the right end side in a mold described later.

  FIG. 3 is a diagram schematically illustrating a state when the OA blade 1 as described above is manufactured by the mold ML. This mold ML is composed of a lower mold 10 and an upper mold 15, and a cavity CA into which a material MA for forming the rubber member is poured is set on the lower mold 10 side. In such a mold ML, the metal plate 2 is set between the lower mold 10 and the upper mold 15 as shown in the figure. Here, a part of the cavity CA is formed via the illustrated runner RN and gate GA. Material MA will be poured into the inside. A through hole 2HL is formed at a predetermined position of the metal plate 2, and the material MA is poured into the cavity CA of the lower mold 10. The cavity CA may be formed on the upper mold 15 side.

  As a countermeasure against short SH that occurs at the boundary surface between the metal plate 2 and the rubber member, it is a general countermeasure to provide a gas vent structure that allows the staying gas to escape, but as pointed out earlier, the adoption of the gas vent structure Induces the occurrence of burrs. The OA blade mold according to the present embodiment described below can solve such a conventional problem and can be efficiently manufactured not only by suppressing the occurrence of a short circuit but also by suppressing the occurrence of a burr. Designed.

Hereinafter, the surface of the mold is roughened, so that not only short-circuiting but also generation of burrs is suppressed during manufacturing, and the OA for the embodiment according to the present invention is designed to be efficiently manufactured. The blade mold will be described.
The rough surface processing here is a fine concavo-convex structure provided on the surface of the mold in order to release the gas generated from the rubber member 3 and the air in the cavity, by roughening the surface of the mold. Formed. The fine concavo-convex structure here may function as a buffer structure that stores gas at a position deviated from the cavity CA, or functions as a part of a discharge path that discharges gas from the cavity CA to the outside of the mold. You may do. Such a structure that acts to evacuate unnecessary gas from the cavity CA is referred to as a gas escape mechanism. The roughened surface portion that acts as a gas escape mechanism is extremely fine, and is formed so as to allow the passage of gas but not the material of the rubber member.

  The OA blade mold according to the present invention described below is designed to suppress the occurrence of shorts and burrs during manufacturing, and the metal plate used for the OA blade has high smoothness as before. A metal plate may be used. However, if the same rough surface processing is applied to the metal plate to be used, short-circuiting and burrs can be more reliably suppressed.

  An OA blade mold according to an embodiment suitable for manufacturing an OA blade will be described below. FIG. 4 is a plan view schematically showing the structure of the lower mold 10 which is one of the molds used when manufacturing the OA blade 1. Here, the upper die (not shown) has a shape corresponding to the lower die 10, and when placed on the lower die 10, a shape corresponding to the OA blade 1 is formed inside.

  The lower mold 10 illustrated in FIG. 4 is designed so that a plurality of OA blades 1 (see FIG. 2) can be manufactured simultaneously. The lower mold 10 is designed so as to take a plurality (four in the illustration of FIG. 4). In FIG. 4, four cavities CA-1 to CA-4 are formed in the lower mold 10 so as to simultaneously manufacture four OA blades. A metal plate 2 (see FIG. 2) is set at a predetermined position of the lower mold 10. At this time, the cavities CA-1 to CA-4 are present below the metal plate 2. Therefore, after setting the metal plate 2 preliminarily coated with the primer, the upper part is closed with an upper mold (not shown), the material is filled in the cavities CA-1 to CA-4, and the rubber member 3 is formed by curing the material. The OA blade 1 provided at a predetermined position can be manufactured.

  A characteristic structure applied to the lower mold 10 will be described in detail. The lower mold 10 is formed with four shallow recesses DE-1 to DE-4 in which the metal plate 2 is set, and the cavities CA-1 to CA- formed in a deeper recess at the center. 4 exists. The shallow recesses DE-1 to DE-4 provided in the lower mold 10 can be omitted.

  Then, the surface of the lower mold 10 excluding the cavities CA-1 to CA-4 (roughly shaded area) is roughened. Here, as a processing technique for roughing the surface, a conventionally known surface processing technique can be adopted. For example, physical roughening such as knurling, iris processing, sandblasting, or the like, or roughening by chemical corrosion (etching) such as embossing may be adopted. Furthermore, an electric or optical rough surface processing technique such as electric discharge machining may be employed. If necessary, a plurality of rough surface processing may be appropriately combined. By this rough surface processing, a gas escape mechanism is set on the surface of the lower mold 10 that allows unnecessary gas that causes a short circuit to pass but does not allow the material of the rubber member to pass.

  Stainless steel (SUS) or phosphor bronze is used as the material for the metal plate, but in the case of a mold, a different material (for example, steel, SKD-based, SUS-based pre-hardened steel or quenching is used. It is desirable to use tempered steel.

The surface roughness of the lower mold 10 is an Ra value (center line average roughness, arithmetic average roughness: average value of absolute value deviation from the average line) or Ry value (maximum height: reference length), which is an index of roughness. The height from the lowest valley floor to the highest mountain peak) may be set. The Ra value of the lower mold 10 is preferably 0.10 to 0.30 μm, and the Ry value is preferably 1.0 to 3.0 μm. If the surface of the lower mold 10 is roughened so as to satisfy this condition, it can be used to remove unnecessary gas remaining in the cavity that causes a short circuit. Note that the Ra value of a conventional mold having a smooth surface is about 0.05 to 0.08, and the Ry value is about 0.5 to 0.8.
In addition, the area to be roughened on the mold surface may be limited to a certain portion where the outer edge of the rubber member (outer peripheral edge of the rubber member) where gas tends to stay is expected to be located, In some cases, roughing a part of the surface may be cumbersome. Therefore, it is preferable to roughen the entire surface except the cavity CA as in the illustrated example.

  FIG. 5 is a view showing a mold in which a metal plate is set between the upper and lower molds. The mold 5 is shown with an upper mold 15 that is not shown above, and preferably has a cold runner structure, an overflow structure, a vacuuming structure, and the like.

  As shown in FIG. 5, a part of runner parts 23 and 24 is enclosed by the cooling jacket 26, and is comprised as a cold runner which can be cooled. The runner portion 24 that forms a cylindrical space is in contact with a cylindrical cooling jacket 26 via a bush 25 that forms the cylindrical space. The cooling jacket 26 has a cooling pipe 27 through which a cooling medium, for example, cooling water, passes. The runner 24 provided in the cylinder of the cooling jacket 26 is cooled by guiding the cooling medium to the cooling pipe 27 and passing therethrough, and a thermosetting material MA such as liquid silicone passing through the cooling medium 26. The temperature is kept at a temperature at which curing is difficult to proceed so as not to be cured. In FIG. 5, PL is a parting line, the upper die 15 is the upper die 15 and the lower die 10 is the lower die.

  Around the cavity CA of the lower mold 10, a heater 32 for curing the thermosetting material MA injected into the cavity CA is provided not only on the lower mold 10 but also on the lower side of the upper mold 15. On the other hand, even if the material MA stays in the runner portions 23 and 24, the upper mold 15 is provided with a cooling pipe 31 so as not to be cured. The cooling pipe 31 cools the entire upper side of the upper mold 15 separately from the cold runner structure around the runner portion 24. In the middle of the upper mold 15, heat insulating layers 28 and 29 are arranged as a preferable structure for increasing the thermal efficiency.

  Again, a description will be given with reference to FIG. In the mold 5, thermosetting liquid silicone is employed as a material for forming the rubber member 3. Such a material is filled (injected) from the external injection device 40 into the cavity CA (space) formed in the shape of the rubber member 3 through the gate 14. Here, the OA blade including the sharp rubber member 3 can be manufactured by filling the material while preventing unnecessary gas from staying in the cavity.

  The structure that the mold 5 preferably has will be further described with reference to FIG. The lower mold 10 is provided with a sealing packing 17 around the cavities CA-1 to CA-4, and a vacuum pulling portion 18 inside the packing 17 (passing under the packing in FIG. 4). Is provided. The evacuation unit 18 is connected to an external gas suction device 19 so as to evacuate the periphery of the cavity in the packing 17. If the vacuum drawing structure is further provided in this way, the surroundings of the cavity can be adjusted to a low pressure, so that a short circuit can be generated by smoothly guiding unnecessary gas to the unnecessary gas retraction structure formed by roughing. It can be surely prevented.

Since the mold described above has a rough surface on the surface of the lower mold, as in the case of the metal plate described above, unnecessary gas is generated when material is injected into the cavity CA in the manufacturing process. Even in such a case, unnecessary gas can be removed from the cavity by the roughened surface portion acting as an unnecessary gas saving structure. Therefore, occurrence of a short circuit can be prevented. Further, the roughened portion is extremely fine and allows the passage of gas but does not allow the material of the rubber member to pass. Therefore, since the OA blade 1 described above suppresses not only a short circuit but also burrs during manufacturing, it can be manufactured efficiently.
In addition, the example demonstrated above is a metal mold | die which provides a cavity in a lower mold | type, and it is effective to give a rough surface process to the surface of a lower mold | type, but this is one form example. It is good also as a metal mold | die which formed the cavity in the upper mold | type and provided the rough surface process on the surface (lower surface) of the upper mold | type.

  Below, the Example at the time of manufacturing the blade for OA using the metal mold | die which gave the rough surface process is described.

(Example)
FIG. 6 is a diagram showing another embodiment in which a plurality of dies having a roughened surface are prepared on the surface with which the metal plate contacts to produce an OA blade. In this embodiment, the OA blade has a complicated shape with a notch.
This FIG. 6 can confirm that the short SH which generate | occur | produces that the Ra value of a metal mold | die surface is 0.14-0.30 can be suppressed. Furthermore, it was confirmed that the occurrence of a short circuit can be controlled more reliably by adjusting the Ra value of the plate used.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims.・ Change is possible.

  As is apparent from the above description, according to the present invention, it is possible to provide an OA blade mold that can be manufactured while suppressing the occurrence of short circuits and burrs. Such OA blade molds contribute to an improvement in manufacturing yield.

It is a schematic diagram which shows the state which attached the blade for OA manufactured with the metal mold | die which concerns on embodiment to the OA apparatus. It is the top view which showed the structural example of the blade for OA manufactured with the metal mold | die which concerns on embodiment. It is the figure which illustrated roughly the mode when manufacturing the blade for OA with a metal mold | die. It is the top view which showed typically the structure of the lower mold | type which is one side of the metal mold | die used when manufacturing the braid | blade for OA. It is the figure which showed the metal mold | die made into the state which set the metal plate between the upper and lower molds. It is the figure shown about the Example at the time of preparing the metal mold | die which gave the rough surface process to the surface which a metal plate contacts, and manufacturing the blade for OA. It is the figure which expanded and showed a part of rubber member affixed on the metal plate of the blade for OA conventionally. It is the figure shown about the case where a gas escape part is installed in the part which is easy to generate | occur | produce a short circuit with the conventional metal mold | die.

Explanation of symbols

1 Blade for OA 2 Metal plate (plate)
3 Rubber member (elastic member)
5 Mold 10 Lower mold 14 Gate 15 Upper mold 18, 19 Vacuum drawing structure CA (CA-1 to CA-4) Cavity SH Short

Claims (4)

A mold used for manufacturing an OA blade in which an elastic member is provided along a longitudinal direction on a long plate,
An OA blade mold, wherein a surface on which the plate is set is roughened.   The OA blade mold according to claim 1, wherein the Ra value of the mold surface roughness is 0.10 to 0.30 μm. The mold is composed of an upper mold and a lower mold, and a cavity corresponding to the shape of the elastic member is formed in the upper mold or the lower mold, and the plate is set. And
2. The OA blade mold according to claim 1, wherein the surface of the mold on which the cavity is formed is roughened. 3.   The OA blade mold according to any one of claims 1 to 3, wherein the mold further includes a vacuum drawing structure for evacuating the periphery of the cavity.

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