JP4246335B2 - Roller manufacturing method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for manufacturing a roller made of an elastic material used as a toner conveying roller, a charging roller, a transfer roller, a cleaning roller, a paper feeding roller, a fixing roller, etc. .
[0002]
[Prior art]
An example of a method and apparatus for manufacturing this type of roller is disclosed in Japanese Patent Application Laid-Open No. 8-207172 filed by the present applicant.
[0003]
In this conventional method for manufacturing a roller, a masking cap (cap) is fitted to both ends of a core shaft (core metal), and a cylindrical elastic body layer is formed around the core shaft as it is. The masking cap is removed from the core shaft after the formation of the conductive film on the outer peripheral surface of the elastic layer and the other processes are completed.
[0004]
[Problems to be solved by the invention]
However, in the above-described conventional method, the work of removing the masking cap from the end of the core shaft must be performed at the final stage of the manufacturing process, which is complicated and uses a knife or the like. Otherwise, there is a problem that a flash or the like remains at the end of the elastic layer, and further a flash removal operation is required thereafter.
[0005]
In view of the above-described problems of the prior art, the present invention can reduce the work process by eliminating the work of removing the masking cap from the core shaft in the final stage of the manufacturing process, and can reduce the end of the elastic layer. It is an object of the present invention to provide a roller manufacturing method and apparatus that can reduce the flash generated in the section and can quickly manufacture a roller having a beautiful appearance.
[0006]
[Means for Solving the Problems]
According to the present invention, the above problem is solved as follows.
(1) In the roller manufacturing method, both end portions of the round hole-shaped molding hole in the molding die are respectively closed with end caps, and fitted into the center of the insertion portion fitted in the molding hole in each end cap. A fitting hole is provided, and the inner peripheral surface of the end of the fitting hole that opens into the molding hole is a reverse tapered surface that expands toward the tip, and the fitting hole is fitted to both ends of the core shaft. By fitting the masking cap, the core shaft is arranged in the center of the molding hole, and the elastic material is put into the space around the core shaft in the molding hole from the injection hole drilled in one of the end caps. By filling and solidifying, an elastic body layer is formed around the core shaft, and then the end cap is detached from the mold, the core shaft and the elastic body layer together with the masking cap, and then the core shaft and Disengaging the sex layer from the mold.
[0007]
(2) In the above item (1), the masking cap is formed integrally with the end cap, and the end of the core shaft is directly fitted into the masking fitting hole formed in the center of the end cap. .
[0008]
(3) In the roller manufacturing apparatus, a molding die having a round hole-shaped molding hole and a detachably fitted to each end portion of the molding hole of the molding die to close each end portion, and to form the molding hole A fitting hole is provided in the center of the fitting insertion portion fitted therein, and the inner peripheral surface of the end portion of the fitting hole that opens into the molding hole is a reverse tapered surface that extends toward the tip, and A pair of end caps each having at least one material injection hole communicating with the forming hole are fitted, and the end of the roller core shaft is fitted to the inner surface, and is fitted to the fitting hole of each end cap. By doing so, the core shaft is provided with a masking cap that is arranged at the center of the molding hole.
[0009]
(4) In the above item (3), the small-diameter end of the reverse tapered surface and the inner end of the masking cap are substantially matched.
[0010]
(5) In a roller manufacturing apparatus, a molding die having a round hole-shaped molding hole and a detachably fitted to each end portion of the molding hole of the molding die to close each end portion, and a molding hole A fitting hole is provided in the center of the fitting insertion portion fitted inside, and an inner peripheral surface of an end portion that opens into the molding hole in the fitting hole is a reverse tapered surface that extends toward the tip, and By fitting the end of the core shaft of the roller into the fitting hole, the core shaft is arranged at the center of the molding hole, and at least one of the material injection holes communicating with the molding hole is formed. And a pair of end caps.
(6) In the above item (5), the material injection hole is opened on the reverse tapered surface of the end cap.
[0011]
(7) In any one of the above items (3) to (6), a protrusion facing the direction of the core axis is provided on the opening edge of the material injection hole on the molding hole side.
[0012]
(8) In any one of the above items (3) to (7), the plurality of material injection holes are provided so as to be distributed in the circumferential direction around the core axis.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
(1) is a core shaft, and (2) and (3) are fitted to the upper and lower ends of a round hole-shaped molding hole (4a) formed in a cylindrical molding die (4) facing vertically. And an end cap that holds the upper and lower ends of the core shaft (1) so that the core shaft (1) is positioned at the center of the molding hole (4a).
[0014]
The molding die (4) has an inner diameter equal to the outer diameter of the elastic body layer (16) (see FIGS. 2 and 3) of the desired roller (R) to be manufactured and has a length of the molding die (4a). It is a cylindrical member that is slightly longer than the length of the elastic layer (16) and is open at both ends, and the material thereof is not particularly limited, and resin, metal, etc. can be used, and preferably the inner surface thereof is a fluororesin. It is preferable to improve the releasability by coating.
[0015]
The upper and lower end caps (2) and (3) are composed of an outer cylinder member (5) and a masking cap (6) formed of a general resin material such as polypropylene, polyethylene, nylon, or the like.
As shown in FIGS. 5 and 6, the outer cylinder member (5) is provided with a nozzle hole (7) that penetrates the outer cylinder member (5) in the vertical direction and gradually decreases in diameter. The outer end portion (upper end portion in FIG. 5) of the nozzle hole (7) is an injection portion (8) of the material for forming the elastic layer (16), and the inner end portion (lower end portion in FIG. 5) is A small-diameter fitting hole (9) for fitting the masking cap (6) is formed, and an inward flange (10) is formed at the outer end of the fitting hole (9).
[0016]
The inner end portion of the outer cylinder member (5) is a fitting insertion portion (5a) that fits into both end openings of the molding hole (4a) of the molding die (4), and the tip of the fitting insertion portion (5a). The inner peripheral surface of the part is an inversely tapered surface (11) that expands toward the tip .
[0017]
The outer periphery of the tip of the reverse tapered surface (11) is all processed to have the same diameter, and when this portion comes into contact with the inner surface of the molding hole (4a) of the molding die (4), the reverse tapered surface (11 ) Is connected to the inner surface of the molding hole (4a) without any step (see FIGS. 1 and 2).
[0018]
The masking cap (6) is preferably formed of a general resin material such as polypropylene, polyethylene, nylon, etc., as with the outer cylinder member (5), as shown in FIGS. The bottom end of the masking cap is closed and the core shaft (1) is fitted with a fitting hole (6a) for fitting the core shaft. Three or more outer ribs (13) in the example shown on the outside (13) Is formed in the axial direction, and a groove (14) penetrating in the axial direction is formed between the outer ribs (7).
[0019]
The outer diameter and length of the masking cap (6) are substantially equal to the inner diameter and length of the fitting hole (9) of the end caps (2) and (3), and the inner end of the masking cap (6) is a reverse tapered surface. It is set to match the small diameter end of (11). In this example, six material injection holes (15) dispersed in the circumferential direction around the fitting hole (6a) are formed by the inner surface of the fitting hole (9) and the groove (14). (See FIG. 9).
[0020]
Next, the roller manufacturing method of the present invention performed using the apparatus as described above will be described.
[0021]
First, the masking cap (6) is put on both ends of the core shaft (1), the core shaft (1) is inserted into the mold (4), and the masking cap (6) is fitted to the outer cylinder member (5). The hole (9) is fitted into the masking cap (6) so that the outer edge of the masking cap (6) is brought into contact with the inward flange (10) and positioned, and the fitting portion (5a) is inserted into the molding hole (4a) of the mold (4). ) Is fitted into the end opening.
In this state, the inner end of the masking cap (6) coincides with the small diameter end of the reverse tapered surface (11) (see FIGS. 1, 2 and 10).
[0022]
At this time, as shown in FIGS. 9 and 10, the outer rib (13) contacts the inner surface of the fitting hole (9), and the material injection hole is formed by the groove (14) and the inner surface of the fitting hole (9). (15) is formed, and the injection portion (8) communicates with the filling space (S) of the material formed between the mold (4) and the core shaft (1) (see FIG. 1). ).
[0023]
When a curable material for forming the elastic body layer (16) is injected from the upper (or lower) end cap (2), this material is injected from the injection portion (8) as shown by an arrow in FIG. It enters the filling space (S) through the hole (15) and fills the inside of the lower (or upper) end cap (3) (see FIG. 2).
[0024]
When the material is solidified, an elastic body layer (16) is formed. After that, when the upper and lower end caps (2) and (3) are pulled outward, the reverse tapered surface (11) becomes elastic layer (without resistance). The elastic layer (16) is peeled off from 16), and the elastic layer (16) is cleanly cut at the small diameter end portion of the reverse tapered surface (11) having the smallest thickness. At this time, the masking cap (6) is integrated with the outer cylinder member (5) by friction with the solidified material, and is smoothly removed from both ends of the core shaft (1) (see FIG. 3).
[0025]
Finally, when the mold (4) is released, the roller (R) shown in FIG. 4 is obtained.
[0026]
Next, a second embodiment of the present invention will be described with reference to FIGS.
The same members as those in the first embodiment are given the same reference numerals, and detailed descriptions thereof are omitted.
[0027]
The end caps (20) and (21) of the present embodiment are formed by integrally forming the outer cylindrical member (5) and the masking cap (6) of the first embodiment. For example, polypropylene, polyethylene, nylon, etc. It is preferable to mold with a general resin material.
[0028]
At the inner ends of the end caps (20) and (21), that is, at the lower end of the end cap (20) shown enlarged in FIG. 14, a reverse taper surface (22) that expands toward the tip is formed.
[0029]
In the center of the small diameter end of the reverse tapered surface (22), a bottomed fitting hole (23) is formed, the fitting hole (23) in a circumferential direction around the reverse tapered surface (22) A large number of material injection holes (24) communicating with the injection part (8) are opened at equal intervals.
[0030]
As shown in FIG. 16, at the edge of the opening on the side of the molding hole (4a) in each material injection hole (24), a minute protrusion extending in a tip shape toward the inside of the fitting hole (23). (25) is formed. By this projection (25), the flow of the material supplied into the molding hole (4a) through the material injection hole (24) is deflected toward the core axis (1), that is, in the centripetal direction, and the material When the end caps (20) and (21) are removed after curing, the cured material is cut beautifully at the projections (25).
[0031]
Next, a roller manufacturing method of the present invention using the apparatus of the second embodiment as described above will be described.
First, the core shaft (1) is inserted into the molding die (4), and the fitting holes (23) of the upper and lower end caps (20) and (21) are fitted to both end portions thereof, so that the upper and lower end caps ( 20) Fit (21) into the openings at both ends of the mold (4).
[0032]
In this way, the injection part (8) of the end caps (20) and (21) communicates with the filling space (S) via the plurality of material injection holes (24) (see FIG. 1).
[0033]
When a material for forming an elastic layer is injected into the upper (or lower) end cap (20), the material enters the filling space (S) through the injection hole (24), and the lower end cap (21). (See Fig. 2).
[0034]
After the elastic body layer (16) is formed by curing the material, when the end caps (20) and (21) are pulled outward, the reverse tapered surface (22) is first opened, so the elastic body layer without resistance. The elastic layer (16) is peeled off from (16), and the elastic layer (16) is beautifully cut at the small diameter end portion of the reverse tapered surface (22) having the smallest thickness (see FIG. 13).
[0035]
Finally, if the mold (4) is released, a roller (R) similar to that shown in FIG. 4 can be obtained.
[0036]
The material injection holes (15) and (24) may be provided only in one of the end caps (2), (20) (or (3), (21)). When both are provided, one of them functions as an air vent hole.
[0037]
【The invention's effect】
According to the first and third aspects of the invention, when the end cap is released from the mold, the masking cap is also detached from the core shaft at the same time. It is not necessary to separate from the core shaft, so that the number of work steps can be reduced and the work time can be shortened.
[0038]
In addition, according to the first, third, and fifth aspects of the present invention, since the reverse tapered surface is formed on the inner surface of the end cap, the end cap can be easily peeled off from the formed elastic body layer, and the reverse tapered surface is also formed. Since the core shaft is fitted in the center on the small diameter end side, the boundary between the core shaft and the elastic body layer becomes beautiful, and the occurrence of flash or the like can be suppressed.
[0039]
According to the second and fifth aspects of the present invention, since the core shaft may be directly fitted into the fitting hole of the end cap, the masking cap is fitted to the end portion of the core shaft as in the prior art. It is possible to complete two operations such as fitting the end cap with the end cap in one operation.
[0040]
According to the invention described in claim 4, since the small-diameter end of the reverse tapered surface and the inner end of the masking cap substantially coincide with each other, even in the case of using the masking cap, the occurrence of flash or the like is effectively suppressed, and a beautiful appearance Can be presented.
[0041]
Further, according to the invention described in claim 5, the configuration of the apparatus can be simplified and the number of parts of the apparatus can be reduced.
[0042]
According to the sixth aspect of the present invention, when the end cap is detached, the material other than the elastic body layer is cut along the reverse tapered surface , so that a beautiful and beautiful appearance can be exhibited.
[0043]
According to the seventh aspect of the present invention, when the material is injected, the projections deflect the material flow toward the core axis, and the material is uniformly filled into the space in the molding hole on the side opposite to the injection direction. In addition, when the end cap is detached after the material is hardened, the projections act as a sharp blade for separating excess material, and the occurrence of flash or the like can be effectively prevented.
[0044]
According to the eighth aspect of the invention, by dividing the material injection hole into a plurality of parts and uniformly dispersing the material injection hole, the flow of the material to the forming hole can be made uniform and the occurrence of flash and the like can be suppressed. it can.
[Brief description of the drawings]
FIG. 1 is a longitudinal front view showing a state before material injection in a first embodiment of a roller manufacturing apparatus of the present invention.
FIG. 2 is also a longitudinal front view showing a state after injecting a material.
FIG. 3 is also a longitudinal front view showing a state in which the end cap is removed from the mold.
FIG. 4 is a longitudinal sectional front view showing the completed state of the roller.
FIG. 5 is an enlarged vertical front view of the outer cylinder member of the end cap, similarly.
FIG. 6 is similarly an enlarged bottom view.
FIG. 7 is an enlarged front view of the masking cap, similarly.
FIG. 8 is similarly an enlarged plan view of a masking cap.
FIG. 9 is an enlarged bottom view of the end cap when the end cap is fitted.
FIG. 10 is an enlarged longitudinal sectional front view of the main part showing a state where the end cap is fitted to the end of the core shaft.
FIG. 11 is a longitudinal front view showing a state before material injection in the second embodiment of the apparatus of the present invention.
FIG. 12 is also a longitudinal front view showing a state after injecting a material.
FIG. 13 is also a longitudinal front view showing a state where the end cap is removed.
FIG. 14 is an enlarged longitudinal sectional front view of the end cap.
FIG. 15 is similarly an enlarged bottom view.
FIG. 16 is an enlarged longitudinal sectional front view similarly showing the vicinity of the outlet of the injection hole in the end cap.
[Explanation of symbols]
(1) Core shaft
(2) (3) End cap
(4) Mold
(4a) Molding hole
(5) Outer cylinder member
(5a) Insertion section
(6) Masking cap
(6a) Mating hole
(7) Nozzle hole
(8) Injection part
(9) Mating hole
(10) Inward flange
(11) Reverse taper surface
(13) Outer rib
(14) Groove
(15) Material injection hole
(16) Elastic layer
(20) (21) End cap
(22) Reverse taper surface
(23) Mating hole
(24) Material injection hole
(25) Protrusion
(R) Roller
(S) Filling space

Claims (8)

Both end portions of the round hole-shaped molding hole in the molding die are closed with end caps, and a fitting hole is provided at the center of the fitting insertion portion fitted to the molding hole in each end cap. The inner peripheral surface of the end portion that opens into the molding hole is a reverse tapered surface that expands toward the tip, and the fitting hole is fitted with a masking cap fitted to both end portions of the core shaft. The core shaft is disposed in the center of the molding hole, and the elastic material is filled into the space around the core shaft in the molding hole and solidified from the injection hole formed in one of the end caps. An elastic body layer is formed around the shaft, and then the end cap and the masking cap are detached from the mold, the core shaft and the elastic body layer, and then the core shaft and the elastic body layer are detached from the mold. This Method for manufacturing a roller according to claim.   The masking cap is formed integrally with the end cap, and the end of the core shaft is directly fitted into a masking fitting hole formed in the center of the end cap. Manufacturing method of the roller. A mold having a round hole-shaped molding hole;
A fitting hole is provided in the center of the fitting insertion portion fitted into each end of the molding die so as to be detachably fitted and closed, and fitted into the molding hole. A pair of ends in which the inner peripheral surface of the end portion of the joint hole that opens into the molding hole is a reverse tapered surface that expands toward the tip, and at least one of the material injection holes that communicate with the molding hole is formed. A cap,
A masking cap configured to fit the end portion of the core shaft of the roller to the inner surface and to fit the fitting hole of each end cap so that the core shaft is disposed at the center of the molding hole; A roller manufacturing apparatus characterized by the above. The roller manufacturing apparatus according to claim 3, wherein the small-diameter end of the reverse tapered surface is substantially coincident with the inner end of the masking cap. A mold having a round hole-shaped molding hole;
A fitting hole is provided in the center of the fitting insertion portion fitted into each end of the molding die so as to be detachably fitted and closed, and fitted into the molding hole. The inner peripheral surface of the end portion that opens into the forming hole in the joint hole is a reverse tapered surface that expands toward the tip, and the end portion of the core shaft of the roller is fitted into the fitting hole. And a pair of end caps each provided with a material injection hole communicating with the molding hole. At least one of the end caps is provided with a roller manufacturing apparatus. The roller manufacturing apparatus according to claim 5, wherein the material injection hole is opened on the reverse tapered surface of the end cap.   The manufacturing method of the roller in any one of Claims 3-6 which provided the protrusion which faces the direction of a core shaft in the opening edge part by the side of the shaping | molding hole in a material injection hole.   The roller manufacturing apparatus according to any one of claims 3 to 7, wherein the plurality of material injection holes are provided so as to be distributed in a circumferential direction around the core axis.

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