JP2002307461A - Mold for centrifugal molding and seamless belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold for centrifugal molding which can obtain a seamless belt, etc., from which a material layer can be removed simply, and which has a high face precision, and the seamless belt. SOLUTION: The rotatable mold 6 in which resin is charged from a centrifugal molding apparatus is formed cylindrically. The mold 6 is composed of a molding mold 7 for molding a product, weir molds 9 which are engaged attachably/detachably with both end parts of the molding mold 7 respectively, setting molds 14 for the centrifugal molding apparatus which are engaged attachably/detachably with the free end parts of the weir molds 9, and lid bodies 15 which are engaged attachably/detachably with the free end parts of the setting molds 14. Since the seamless belt 8 can be peeled by removing the weir molds 9 from the molding mold 7, a step is not necessary to be processed in the mold 6, and the belt 8 can be removed simply and safely from the mold 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal molding die and a seamless belt used for forming a seamless belt used in an electrophotographic copying machine, a laser printer, and the like.

[0002]

2. Description of the Related Art Conventionally, a seamless belt used in an electrophotographic copying machine, a laser printer or the like is formed to be flexible and endless by a centrifugal molding method using a resin material. Specifically, although not shown, a fluid resin material is charged into a rotating cylindrical mold to form a resin layer longer than the product size, and after the solvent is volatilized or reacted and solidified, the resin layer is removed from the mold. Remove and remove. Then, by cutting both ends of the extracted resin layer to adjust the length in the axial direction, a seamless belt can be manufactured.

[0003]

However, if a seamless belt is manufactured by cutting both ends of a resin layer, the seamless belt may be damaged at the time of cutting, or an error may occur in the perpendicularity to the axial direction of the seamless belt. Or
Alternatively, there is a problem that the strength is deteriorated due to minute cracks at the time of cutting. Conventionally, as a means for solving such a problem, a step is cut in a mold or a ring-shaped weir is formed on an inner peripheral surface of a mold to control a flow of a resin material. Has been proposed. However, when a step is formed in a mold, it is extremely difficult to separate and remove the resin layer from the mold. In addition, when processing a weir in a mold, the diameter of the inner peripheral surface of the mold is partially different, so polishing or plating of the inner peripheral surface of the mold becomes extremely difficult, and a seamless belt having excellent surface accuracy is required. The big problem that cannot be obtained newly arises.

The present invention has been made in view of the above, and a centrifugal molding die capable of easily removing a material layer from a die and obtaining a molded product such as a seamless belt having excellent surface accuracy. And a seamless belt.

[0005]

According to the first aspect of the present invention, in order to achieve the above object, a rotatable mold into which a molding material is charged is formed in a substantially cylindrical shape.
The mold is divided into a mold for molding a product and a weir mold removably attached to at least one end of the mold. It is preferable to include an installation mold for a centrifugal molding device detachably attached to the free end of the weir mold, and a lid detachably attached to the free end of the installation mold.

Further, in the invention according to claim 3,
In order to achieve the above object, a centrifugal molding die according to claim 1 or 2 is used for centrifugal molding.

Here, the molding material in the claims may be a thermoplastic resin or a thermosetting resin. The substantially cylindrical shape includes both a cylindrical shape and a substantially cylindrical shape. Further, the weir mold may be any that can be detachably attached to at least one end of the mold, and may be detachably attached to both ends of the mold. Centrifugal molding
(Method) means that a fluid molding material is injected into a mold, the mold is rotated, a material layer is formed on the inner peripheral surface of the mold by centrifugal force, and the material layer is solidified by a predetermined method. And release from the mold. Further, the seamless belt may be any of conductive, semiconductive and insulating, and may be a composite of these. Furthermore, the mold for centrifugal molding according to the present invention is mainly used for molding a seamless belt used as an intermediate transfer belt, but is also used for molding other molded products such as pulleys, rotors, and wheels. Is possible.

According to the first aspect of the present invention, when manufacturing a hollow body, the assembled mold is rotated and a fluid molding material is charged into the inside of the mold to form a hollow material layer. Centrifuge. Then, if the mold is disassembled into a mold and a weir mold and the solidified material layer is taken out from the mold, a hollow body can be manufactured. If the diameters of the mold and weir are different,
If the mold and the weir mold are made removable in the axial direction at the boundary portions having different diameters, the inner peripheral surface of the mold can be polished substantially uniformly. According to the second aspect of the present invention, since the installation mold is attached to the weir mold and the mold is extended in the axial direction, not only the rotary drive part of the new centrifugal molding apparatus but also the centrifugal molding of the existing standard The mold can also be supported on the rotary drive of the device. Further, since the lid is attached to the installation mold, even if the molding material gets over the weir mold, the molding material does not flow out of the mold.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the drawings. A centrifugal molding die according to the present embodiment is, as shown in FIGS. A rotatable mold 6 into which a resin material is charged is formed in a cylindrical shape, and this mold 6 is used as a molding mold 7 for product molding.
A weir mold 9 removably fitted to both ends of the molding die 7, and an installation mold 14 for the centrifugal molding device 1 removably fitted to the free end of each weir mold 9. Each of the installation dies 14 is divided into a free end portion and a lid 15 detachably fitted to the free end portion.

As shown in FIG. 1, a centrifugal molding apparatus 1 includes a plurality of (four in this embodiment) rotating rollers 2 for rotating a mold 6 and a material which can move forward and backward in the axial direction of the mold 6. A supply device 3 is provided. At the tip of the material supply device 3,
The static mixer 4 is mounted horizontally, and a catalyst pump 5 is connected to the static mixer 4 via a connection pipe (see FIG. 1).

As shown in FIGS. 1 to 3, the molding die 7 is formed in a cylindrical shape using a metal material for the mold 6. In the molding die 7, the resin layer of the seamless belt 8 is pressed against the inner peripheral surface by centrifugal force by injecting a fluid resin material from the static mixer 4.

The weir mold 9 is basically formed in a ring shape whose inner diameter is smaller than that of the molding die 7 by using a metal material for the mold 6. As shown in FIG. 3, the weir mold 9 has a weir 10 for regulating the flow of the resin material around its inner peripheral surface in a ring shape. Ring-shaped recesses 11 that are closely fitted to both ends of the molding die 7 are respectively formed in the front and back end surfaces of the weir mold 9, and the molding die 7 and the installation mold 1 are formed in the end surfaces in the depressions 11.
A ring-shaped packing 12 for maintaining the sealing property with the seal 4 is selectively bonded. An operating hinge 13 is provided around the outer peripheral surface of the weir mold 9 in a ring shape. As the packing 12, for example, Teflon (registered trademark) which is excellent in heat resistance, cold resistance, dimensional stability, releasability and the like can be used.
In addition, Teflon (registered trademark) is a registered trademark name, and is a trade name of ethylene tetrafluoride resin manufactured by Dubon.

As shown in FIG. 3, the installation die 14 is
It is formed into a cylindrical shape or a ring shape having the same diameter as the molding die 7 by using a metal material for molding, and is closely fitted to the concave portion 11 of the weir die 9 and is removably mounted and supported on the plurality of rotating rollers 2. further,
The lid 15 is formed in a hollow disk or ring shape so as to penetrate through the static mixer 4 of the material supply device 3, and a concave portion 16 is formed on the outer periphery of the back surface so as to be closely fitted to a free end of the installation die 14. Have been. These forming mold 7, weir mold 9,
The lid body 15 is detachably fixed with bolts and nuts (not shown), or is assembled by fitting unevenness.

In the above configuration, when manufacturing the seamless belt 8, the plurality of rotating rollers 2 are rotated to rotate the mold 6 horizontally supported at a high speed, and the mold 6 is moved from the periphery. A fluid resin material (for example, a thermosetting resin) is axially injected into the mold 6 from the heated and advanced material supply device 3 to form a resin layer, that is, a seamless belt 8 by centrifugation. After that, the mold 6 is removed from the plurality of rotating rollers 2 and disassembled, and the solidified resin layer is separated from the mold 7 and taken out. Thus, a flexible seamless belt 8 that can be bent can be obtained.

According to the above configuration, since the seamless belt 8 is not manufactured by cutting both ends of the resin layer, the seamless belt 8 may be damaged by the cutting, or the perpendicularity to the axial direction of the seamless belt 8 may be caused. Errors may occur,
Alternatively, the strength does not deteriorate due to a minute crack at the time of cutting. Further, since the cutless seamless belt 8 can be peeled off by removing the weir mold 9 from the molding die 7 in the axial direction, there is no necessity of processing an integrated step in the mold 6, and the mold 6 is not required. The resin layer can be easily and safely peeled off and taken out.

Although the diameter of the inner peripheral surface of the mold is partially different, the molding die 7 and the weir die 9 having different diameters can be separated.
The inner peripheral surface of the mold 6 can be extremely easily and uniformly polished and the like, whereby the seamless belt 8 having excellent surface accuracy can be obtained. Further, if the forming die 7, the weir die 9, and the installation die 14 are fitted in a concave and convex manner without using a fastener, smooth, simple, and easy separation and coupling work can be greatly expected. Furthermore, if the hinge 13 protruding from the outer periphery of the weir mold 9 is used not only for operation but also as a positioning guide or the like, it is possible to effectively prevent the mold 6 from falling off the rotary roller 2 or displacing.

Next, FIG. 4 shows a second embodiment of the present invention. In this case, on the inner peripheral surface of the weir 10 of the weir mold 9,
A gradient is formed to regulate the flow of the resin material. The other parts are the same as those in the above-described embodiment, and a description thereof will be omitted. It is apparent that the present embodiment can expect the same operation and effect as the above embodiment.

Next, FIG. 5 shows a third embodiment of the present invention. In this case, the forming die 7 of the die 6, the weir die 9,
A flange 17 is formed on the outer periphery of the installation die 14 so as to protrude therefrom.
7 are superimposed and detachably screwed with a fastener (not shown). The other parts are the same as those in the above-described embodiment, and a description thereof will be omitted. Also in the present embodiment, the same operation and effect as in the above embodiment can be expected, and since it is not a mere connection by fitting, it is possible to further increase the degree of coupling of the molding die 7, the weir die 9, and the installation die 14. Is clear.

In the above embodiment, the mold 6 is rotated by the rotating roller 2. However, the present invention is not limited to this, and the mold 6 may be rotated by a plurality of rotating rolls or the like. In addition, the weir dies 9 are detachably fitted to both ends of the mold 7, but if necessary, weir dies 9 are attached to one end of the mold 7.
May be detachably fitted. If not particularly required, the mold 6 may be composed of the molding mold 7 and the weir mold 9, and the installation mold 14 and the lid 15 may be omitted. Also, the shape of the weir 10 of the weir mold 9 can be freely changed as long as a similar function can be expected. Further, the heat absorbing function can be enhanced by applying black to the outer peripheral surface of the mold 6. Further, the packing 12 and the like may be adhered to the concave portion 16 of the lid 15 to enhance the sealing performance.

[0020]

As described above, according to the present invention, it is possible to relatively easily remove a material layer from a mold and obtain a molded product such as a seamless belt having excellent surface accuracy. effective.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram showing an embodiment of a centrifugal molding die according to the present invention.

FIG. 2 is a front view showing the centrifugal molding die of FIG.

FIG. 3 is an exploded sectional view showing an embodiment of a centrifugal molding die and a seamless belt according to the present invention.

FIG. 4 is an explanatory sectional view showing a second embodiment of a centrifugal molding die according to the present invention.

FIG. 5 is an explanatory view showing a third embodiment of a centrifugal molding die according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Centrifugal molding device 2 Rotary roller 3 Material supply device 6 Mold 7 Mold 8 Seamless belt 9 Weir type 10 Weir 14 Installation type 15 Lid

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F202 AG16 CA04 CB01 CK23

Claims (3)

[Claims] 1. A centrifugal molding die in which a rotatable die into which a molding material is charged is formed in a substantially cylindrical shape, wherein the die is a molding die for molding a product, and at least one end of the molding die. A centrifugal molding die, which is divided into a weir mold detachably mounted on the mold. 2. An installation die for a centrifugal molding device detachably attached to a free end of the weir die, and a lid detachably attached to the free end of the installation die. The mold for centrifugal molding described. 3. A seamless belt formed by centrifugal molding with the centrifugal mold according to claim 1.