JP2001138333A - Apparatus for producing roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for producing a roller good in vibration precision the cost of which can be reduced by simplifying the structure of a cylindrical mold which tends to be abraded and deteriorated as compared with a core metal holding member into the type of a cartridge. SOLUTION: In the apparatus composed of the cylindrical mold 1 into which a core metal 2 is inserted, core metal holding members 3, 4 for holding both ends of the core metal 2, and a base mold 10 which covers the peripheral surface of the cylindrical mold 1, the opening end part space of the mold 1 and the angle engagement bodies 3a, 4a of the holding members 3, 4 are tapered and engaged compensatively, and a means for bonding the members 3, 4 to both ends of the base mold 10 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a laser printer or a facsimile receiving apparatus, and more particularly to a developing roller, a charging roller and a transfer roller which are incorporated in an electrophotographic apparatus employing an electrophotographic process. The present invention relates to an apparatus for manufacturing an elastic roller.

[0002]

2. Description of the Related Art As a roller incorporated in an electrophotographic apparatus, a charging roller for charging the surface of an electrostatic latent image carrier such as a photosensitive drum, and a toner are supplied to the electrostatic latent image carrier to form an electrostatic latent image. There are an elastic roller such as a developing roller that develops by developing the toner image, a transfer roller that transfers the developed toner image to a sheet, and a cleaning roller that removes residual toner on the electrostatic latent image carrier after the transfer. As a method for manufacturing this kind of elastic roller, an injection molding method is widely known. In recent years, as the demand for this kind of elastic roller has increased, competition for price reduction has intensified, and at present, there is an urgent need for a roller manufacturing apparatus that can be manufactured at the lowest possible cost.

FIG. 2 is a schematic sectional view showing a typical example of a conventional injection mold. In the figure, reference numeral 41 denotes a cylindrical mold, 42 denotes a cored bar inserted into the cylindrical mold 41, 43,
44 is a core metal holding member, 45 and 46 are cover members provided with threaded grooves on the inner surface, and 47 is a pin. The procedure of forming an elastic roller using such an injection mold is as follows. First, a metal core 42 is inserted into a cylindrical mold 41, and both ends 42a, 42b thereof are respectively attached to a metal core holding member 43,
The metal core holding members 43 and 44 are fitted into the metal core holding holes 43 a and 44 a opened in the base metal mold 44, and these core metal holding members 43 and 44 are fitted into the cylindrical metal mold 41. Then, the cover members 45 and 46 are covered with the cylindrical metal mold 41 so as to cover them. To form a roller molding space 60 to close the injection mold.

Next, a resin injection nozzle (not shown) is applied to a nozzle mounting hole 49 provided in the cover member 46, and a resin material is supplied through a resin injection hole 44 b formed through the metal core holding member 44 to form a roller molding space 60. After injection and filling, the gas vent hole 50 formed through the cover member 45 is closed with a pin 47, and then the cylindrical mold 41 is heated to heat and cure the resin material. Examples of the heating means include a method in which a heating mechanism (not shown) is brought into contact with the outer surface of the cylindrical mold 41, and a method in which the injection mold is transferred into a hot-blast furnace (not shown) and heated. is there. After the heat curing, the cylindrical mold 41 is cooled, the mold is opened in a procedure reverse to the above, the molded article is released, and the above procedure is repeated again to produce a new molded article.

[0005]

However, the conventional roller manufacturing apparatus as described above has the following problems. In the process of manufacturing the roller, there is considerable release resistance when the molded product is released from the cylindrical mold. Therefore, generally, the inner surface of the cylindrical mold is made of a material having good slipperiness, for example, Ni-based electroless plating. Treatment or fluorine coating treatment. However, by repeating molding in the above procedure, only the inner surface of the cylindrical mold is worn, inevitable deterioration such as abrasion occurs,
The effective life is about 1,000 times. The deteriorated cylindrical mold is subjected to maintenance such as re-plating and used again, but once maintenance is performed, the inner diameter of the cylindrical mold changes slightly and the roller It is preferable to update the cylindrical mold from the viewpoint of obtaining stable quality since the quality of the mold is adversely affected. And even if maintenance such as re-plating is performed on the cylindrical mold, or if the cylindrical mold is newly replaced,
In any case, the removal work of the cylindrical mold and the mounting work are necessary, but in the conventional injection mold, this work is complicated and not suitable for automation, and in addition, when the cylindrical mold is mounted. There is a limit to the positioning accuracy, which has been a factor preventing cost reduction of the roller and improvement of the roller quality.
For example, in the above-mentioned conventional injection molding die, the core metal holding members 43 and 44 are attached to the cylindrical die 41 for mounting the cylindrical die.
There is a process of screwing in the cover members 45 and 46, and the like. However, in this work, if the tightening load at the time of screwing is too large, the cored bar 42 receives an excessive load and tends to buckle. On the other hand, if the tightening load is too small, the resin material leaks due to the pressure of the filling resin, and burrs are formed on the molded product, thereby reducing the moldability of the roller. It is difficult to automate such a delicate adjustment at low cost, and in fact, it still has to rely on human labor. In addition, in order to smoothly attach and detach the core holding member to and from the cylindrical mold, a certain clearance is required between the two, so that it is possible to increase the positioning accuracy between the cylindrical mold and the core holding member. This makes it difficult to perform, and as a result, there are defects such as large run-out of the rollers. In view of the above problems, the present invention seeks to solve the problems described above, because the structure of the cylindrical mold is simple, the cost burden due to the renewal of the cylindrical mold can be reduced, the work of removing and installing the cylindrical mold, and the cylindrical mold concerned. An object of the present invention is to provide a roller manufacturing apparatus which is suitable for automating the installation work in the inside, and has a small amount of run-out of the roller and can be easily centered.

[0006]

In order to solve the above problems, the present inventor has reduced the cost of a roller manufacturing apparatus by simplifying a cylindrical mold having a relatively short life without adding an extra function. As a result of studying an apparatus structure suitable for automating the work of removing and installing the cylindrical mold and the work of installing the same in the cylindrical mold, the present invention was completed. It is a thing.

The present invention, which has solved the above-mentioned problems, is an apparatus for manufacturing a roller in which the outer periphery of a core is covered with a synthetic resin layer in the longitudinal direction, wherein the core is provided with a synthetic resin filling space around the core. A cylindrical mold having a cylindrical shape, forming a predetermined range from the opening end as an inclined inner peripheral surface, and forming a space in which the inner diameter increases toward the opening end in a predetermined range at both ends; A member which is disposed at both ends and closes the open end of the cylindrical mold while holding the end of the core bar, has a slanted outer peripheral surface, and has a shaft end holding hole for receiving and holding the shaft end of the core bar. A core holding member provided with a chevron-shaped fitting body that complementarily fits into a diameter-enlarged space of the cylindrical mold having a center in the direction, and a member that covers an outer peripheral surface of the cylindrical mold; Has a through hole with an inner diameter slightly larger than the outer diameter of the cylindrical mold to mount the mold A base mold, a manufacturing apparatus of a roller and means for fastening the metal core holding member at both ends of the base mold.

The clearance between the outer diameter of the cylindrical mold and the inner diameter of the base mold is preferably 0.01 to 0.1 mm.

Flanges are provided facing the outer periphery of the base mold and the outer periphery of the core holding member, respectively, and the surface pressure between the flanges and the inclined inner peripheral surface of the cylindrical mold and the core holding member are provided. It is desired to set the formation position of the flange portion so that the surface pressure with the inclined outer peripheral surface becomes substantially equal.

It is preferable that the rear side of the surface to be joined of the facing flange portion is an inclined surface, and the outer surface of the abutting flange portion is fastened by a ferrule clamp. A curable liquid resin can be used as the synthetic resin layer covering the outer periphery of the cored bar.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of a roller manufacturing apparatus according to the present invention will be described below with reference to an embodiment shown in FIG.
1 shows a representative embodiment of a roller manufacturing apparatus according to the present invention. This apparatus is an apparatus for manufacturing a roller in which a synthetic resin layer is coated on the outer periphery of a core bar in the longitudinal direction except for both ends. The specific shape of the roller is not limited. The shape is
It may be a straight one having no steps or a one having steps. The material of the metal core is not particularly limited as long as it is a metal material, but the use of a material having a significantly different coefficient of thermal expansion from the material of the present apparatus should be avoided.

As the material of the resin layer of the roller, various synthetic resin materials such as silicone, urethane, NBR, and EPDM are selected. In the present embodiment, for example, a curable liquid resin such as silicone is used. The curable liquid resin is suitable because it can be injected at a low injection pressure because of its low viscosity. As shown in FIG. 1, the manufacturing apparatus includes a cylindrical mold 1, core metal holding members 3 and 4 positioned at both ends of the cylindrical mold 1, and a base mold 10 covering the outer periphery of the cylindrical mold 1. And ferrule clamps 21 and 22 for fastening the core metal holding members 3 and 4 to the base mold 10. Upper and lower metal core holding members 3 and 4 are upper and lower shaft ends 2 of metal core 2 housed in cylindrical mold 1.
a, 2b, and has a function of closing the open end of the cylindrical mold 1. The figure shows a cross section of a state in which the roller manufacturing apparatus before resin injection is assembled.

The cylindrical mold 1 has a roller molding space 30 which is a space for receiving the cored bar 2 and molding a resin molded body therearound.
a, 1b, a space is formed within a predetermined range at both ends, where the inner diameter increases toward the opening end. This space is a space for receiving the angled fitting bodies 3a, 4a formed in the core metal holding members 3, 4. The cylindrical mold 1 is preferably made into a seamless pipe shape, and its inner surface is preferably subjected to a fluorine resin coating or an electroless plating treatment from the viewpoint of mold release. On the other hand, on the upper part and the core holding members 3 and 4, there are formed truncated conical mountain-shaped fitting bodies 3a and 4a which are closely fitted in the enlarged diameter space.
The angled fitting bodies 3a and 4a have inclined outer peripheral surfaces 3b and 4b, and their outer shapes are shaped so as to complementarily fit into the enlarged diameter space of the cylindrical mold 1. Here, complementary fitting means that both members are fitted so as to fill the gap on the other side. Therefore, the angle fittings 3a, 4a
The tapered angles of the inclined outer peripheral surfaces 3b, 4b of the above and the tapered angles of the inclined inner peripheral surfaces 1a, 1b of the cylindrical mold 1 are made to coincide with each other, and the core metal holding members 3, 4 are fastened to the cylindrical mold 1. , The tapered surfaces are tightly joined with almost no gap. The taper angle and the height of the peaks of the angled fitting bodies 3a and 4a are determined in consideration of both the fitting strength and the workability. The positioning accuracy is improved as the taper angle is smaller and the penetration depth of the angled fitting bodies 3a, 4a into the cylindrical mold 1 is higher. However, if the depth is too deep, the upper and lower cored metal holding members 3, 4 are formed after the molding. It becomes difficult to separate from the mold 1. The taper angle θ is preferably in the range of 5 to 20 °.

A shaft end holding hole 3 for receiving the shaft ends 2a and 2b of the cored bar 2 is provided at the center of the top surface of the angled fittings 3a and 4a.
c, 4c are formed respectively. Shaft end holding holes 3c, 4
c corresponds to the shaft end shape of the cored bar 2. Shaft end holding holes 3c, 4c provided in upper and lower core holding members 3, 4
It is preferable that the gap between the shaft end portions 2a and 2b of the metal core 2 is set to 5 to 25 μm. The variation in the shaft diameter of the core 2 is usually
Considering that it is about 5 μm, if it is smaller than this gap, there may be a case where insertion of the core metal 2 is impossible. In addition, if it is forcibly inserted, bending or buckling stress is generated in the cored bar, and run-out increases. On the other hand, if the gap is larger than 25 μm, the degree of eccentricity increases and the run-out increases. The depths of the shaft end holding holes 3c and 4c should be determined so that the metal core 2 does not buckle when the metal core holding members 3 and 4 are fastened to both ends of the cylindrical mold 1. In this embodiment, 20. The length is set to 1 mm to 20.2 mm (provided that the length of the core metal at both ends of the roller molded product not covered with the resin, that is, the shaft end length is 20.0 mm). The clearance between the entire length of the cored bar 2 and the distance between the shaft end holding hole bottom surfaces 3d and 4d is preferably set in the range of 0.05 to 1 mm.

The base mold 10 is provided with a through hole 11 into which the cylindrical mold 1 is loaded. The cylindrical mold 1 is loaded into the through hole 11, and both ends of the cylindrical mold 1 are further provided. The opening is closed by the metal core holding members 3 and 4. Base mold 1
The purpose of the object 0 is to clamp the cylindrical mold 1 and the core metal holding members 3 and 4 with high accuracy. Through hole 11 of base mold 10
The hole diameter is 0.01 to 0.2 mm from the outer diameter of the metal core holding members 3 and 4.
It is preferable to increase the size by 5 mm. If it is less than 0.01 mm, it becomes difficult to attach and detach the cylindrical mold 1 and the base mold 10, and if it exceeds 0.5 mm, this space acts as a kind of adiabatic space. It becomes worse and the curing time is increased.

A flange 10 is provided on the upper and lower outer circumferences of the base mold 10.
a, 10b are formed, and flange portions 3e, 4e corresponding thereto are formed on the outer peripheral surfaces of the core metal holding members 3, 4, and the flange portions 10a, 10b of the base mold 10 and the core metal holding member 3 are formed. ,
The four flanges 3e, 4e face each other and form a pair.
The facing surfaces of these flanges are flat surfaces, and the back surface is an inclined surface. The positions at which the flanges are formed are determined by the flanges 10a and 10b of the base mold 10 and the flanges 3e and 3e of the core metal holding members 3 and 4.
4e and the inclined outer peripheral surfaces 3b and 4b of the angled fitting bodies 3a and 4a and the inclined inner peripheral surfaces 1a and 1b of the cylindrical mold 1 when facing each other.
Are set in such a manner that they contact each other over the entire surface, and the upper and lower chevron fittings 3a, 4a are complementarily and densely fitted in the enlarged space of the cylindrical mold 1. At this time, the core metal 2
The shaft ends 2a, 2b are designed to be housed in the shaft end holding holes 3c, 4c. Also, in order to realize such a design, the axial length of the cylindrical mold 1 and the axial length of the base mold 10 need to be equal. When the axial length of the cylindrical mold 1 is shorter than the axial length of the base mold 10, the flanges 10 a and 10 b of the base mold 10 and the core holding members 3,
4 when the flanges 3e, 4e face each other.
The inclined outer peripheral surfaces 3b and 4b of the cylindrical mold 1 and the inclined inner peripheral surfaces 1a and 1b of the cylindrical mold 1 are not brought into contact with each other over the entire surface.
The cylindrical mold 1 is not fixed.

There are various methods for fastening the core metal holding members 3 and 4 to the base mold 10. In this embodiment, a ferrule clamp is used, and the flange is fastened by the ferrule clamp. Instead of using the ferrule clamp, the abutting flange portions may be bolted together. By joining the flanges together, it is possible to prevent the core metal holding members 3 and 4 from being fastened in a state of being inclined with respect to the cylindrical mold 1.

The setting of the cored bar 2 in the apparatus of the present embodiment having such a configuration is performed as follows. First, one end of the core metal 2 is held by the lower metal core holding member 4, and the cylindrical mold 1 is lowered with respect to the lower metal core holding member 4 in this state, so that the angle fitting 4 a of the lower metal core holding member 4 is moved. The cylindrical mold 1 is made to enter the enlarged diameter space, and is pushed until it comes into contact with the inclined inner peripheral surface 1 b of the cylindrical mold 1. The abutment is performed when the inclined inner peripheral surface 1b of the cylindrical mold 1 and the tapered surface of the angled fitting 4a are in surface contact over the entire surface. Next, the base mold 10 is lowered from above the cylindrical mold 1 and loaded into the cylindrical mold 1.
The butting is performed when the flange portions 10a and 10b of the base mold 10 and the flange portion 4e of the lower metal core holding member 4 come into contact with each other. Next, the contacted flange is tightened by the ferrule clamp 22. When the ferrule clamp 22 is tightened, the inner peripheral edge 22a of the ferrule clamp 22 moves to the inside along the flange inclined surfaces 4f and 10c, and a component force in the fastening direction acts on the facing flange. Further, the lower metal core holding member 4 is tightened until the flange portions contact each other.
Of the core metal holding members 3 and 4 is prevented from being inclined and fastened. The fastening strength is adjusted by the amount of bite into the flange of the ferrule clamp 22. Next, the upper metal core holding member 3 is lowered from above the cylindrical mold 1, the angled fitting 3a is made to enter the cylindrical metal mold 1, and the upper metal core holding member 3 is abutted against the cylindrical metal mold 1. Flanges 3e, 10 in contact with each other after positioning
After a is fastened by the ferrule clamp 21, the molding space is filled with the curable liquid resin. In this apparatus, the holding position of the core metal is changed by simply pushing the inclined inner peripheral surface of the cylindrical mold into the position where the inclined outer peripheral surface of the angled fitting body formed on the core holding member abuts. A roller which is accurately positioned at the design position in the radial direction of the mold and has no runout can be obtained. In addition, these operations do not require delicate adjustments which must rely on humans as in the case of conventional screwing along a thread groove, so that they are suitable for automation and can produce rollers at low cost.

When the curable liquid resin is filled in the molding space, the mold is then heated, whereby the curable liquid resin undergoes an additional reaction and is cured. The heating means is hot air, infrared,
There is no particular limitation on high-frequency induction heating. After the completion of the curing reaction, the mold is cooled and decomposed. When the cooling is sufficiently performed, the molded product shrinks well, so that the mold release is easily performed.

To remove a molded product, first, the ferrule clamps 21 and 22 are loosened to remove the upper and lower core metal holding members 3 and 4, and then the cylindrical mold 1 is removed from the base mold 10. Then, the molded product in the cylindrical mold 1 is released by pressing the core 2 or the like. After release, the mold is cleaned and inspected, then assembled again and molding is repeated. By repeating this molding, the inner surface of the cylindrical mold 1 is deteriorated. Therefore, only an appropriate time is changed for the cylindrical mold. The replacement may be a replacement with a completely new cylindrical mold, or a replacement of a deteriorated cylindrical mold that has undergone maintenance such as re-plating processing and has been regenerated. Since the cylindrical mold is simply provided inside the base mold, replacement of the cylindrical mold is very easy.

[0021]

As described above, the roller manufacturing apparatus of the present invention employs a cartridge system capable of replacing a cylindrical mold having a large degree of deterioration such as abrasion due to repetitive molding, and has a simple structure without providing extra functions. In addition to adopting a mechanism that can easily and accurately position the core metal in this cylindrical mold, it does not require any delicate adjustment that requires human labor when closing the mold, and it can also respond to automation. Since the mechanism is employed, the roller manufacturing cost can be significantly reduced.

According to the present invention, the clearance between the outer diameter of the cylindrical mold and the inner diameter of the base mold is 0.01 to 0.5 mm.
If so, it is easy to attach and detach the cylindrical mold while maintaining good heat conduction from the base mold to the cylindrical mold.

According to a fourth aspect of the present invention, the rear surface of the surface to be joined of the facing flange portion is an inclined surface, and the outer surface of the abutting flange portion is fastened by a ferrule clamp. Simply by tightening the rule clamp, the mold is clamped and the core metal is corrected to a predetermined posture.

As described in claim 5, when the synthetic resin layer covering the outer periphery of the core metal is made of a curable liquid resin, it can be injected at a low injection pressure because of its low viscosity.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an embodiment of a roller manufacturing apparatus according to the present invention.

FIG. 2 is a schematic sectional view of a conventional roller manufacturing apparatus.

[Explanation of symbols]

 Reference Signs List 1 cylindrical mold 1a, 1b inclined inner peripheral surface 2 cored bar 2a, 2b shaft end 3 upper cored bar holding member 4 lower cored bar holding member 3a, 4a angled fitting body 3e, 4e flange 3b, 4b inclined outer peripheral surface 3c, 4c Shaft end holding hole 3d, 4d Shaft end holding hole bottom surface 10 Base mold 10a, 10b Flange portion 10c Flange inclined surface 11 Through hole 21, 22 Herrule clamp 22a Inner peripheral edge 30 Roller forming space 41 Cylindrical mold 42 Metal cores 42a, 42b Core metal ends 43, 44 Metal core holding members 44b Resin injection holes 43a, 44a Metal core holding holes 45, 46 Cover members 45, 46 Cover members 47 Pins 49 Nozzle mounting holes 50 Gas vent holes 60 Rollers Molding space

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 21/10 B29K 101: 10 4F202 // B29K 101: 10 105: 22 105: 22 B29L 31:32 B29L 31 : 32 G03G 21/00 312 F term (reference) 2H003 BB11 CC05 2H032 AA05 BA13 2H034 BC03 2H077 AD06 FA12 3J103 AA02 AA51 EA02 FA15 FA18 GA02 GA52 GA57 GA58 GA60 GA64 GA74 4F202 AA09 AA36 A04 CB15 AD04 CK53 CQ03 CQ07

Claims (5)

[Claims] 1. An apparatus for manufacturing a roller in which a synthetic resin layer is coated on the outer periphery of a metal core in a longitudinal direction, the cylindrical shape being provided with a synthetic resin filling space around the metal core and having an opening. A cylindrical mold in which a predetermined range from the end is formed as an inclined inner peripheral surface, and a space in which the inner diameter increases toward the open end in a predetermined range at both ends is formed, and cores are disposed at both ends of the cylindrical mold, respectively. A member for closing an open end of a cylindrical mold while holding an end of gold, having a slanted outer peripheral surface and having a shaft end holding hole at a radial center for receiving and holding a shaft end of a cored bar. A core metal holding member provided with a chevron-shaped fitting body that complementarily fits into the enlarged diameter space of the mold, and a member that covers the outer peripheral surface of the cylindrical mold; and for mounting the cylindrical mold, A base mold having a through hole with an inner diameter slightly larger than the outer diameter of the cylindrical mold, and holding the core metal Means for fastening members to both ends of the base mold. 2. The roller manufacturing apparatus according to claim 1, wherein a clearance between an outer diameter of the cylindrical mold and an inner diameter of the base mold is 0.01 to 0.5 mm. 3. A flange is provided facing the outer periphery of the base mold and the outer periphery of the core holding member, respectively, and the surface pressure between the flanges, the inclined inner peripheral surface of the cylindrical mold, and the core holding. The roller manufacturing apparatus according to claim 1, wherein the forming position of the flange portion is set such that the surface pressure of the member against the inclined outer peripheral surface is substantially equal. 4. The roller manufacturing apparatus according to claim 3, wherein the rear side of the surface to be joined of the facing flange portion is an inclined surface, and the outer surface of the abutting flange portion is fastened by a ferrule clamp. 5. The roller manufacturing apparatus according to claim 1, wherein the synthetic resin layer covering the outer periphery of the core bar is made of a curable liquid resin.