JP2006007651A - Centrifugal molding machine, centrifugal molding method, and molding system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a centrifugal molding machine which can improve drying efficiency and shorten a drying time, a centrifugal molding machine, and a molding system. <P>SOLUTION: The molding machine in which a quantitative resin solution 22 of a molding material is injected uniformly into a rotating cylindrical mold 1, and the solution 22 is pushed to the inner surface of the mold 1 by centrifugal force to mold an endless belt is equipped with an external heater 30 which heats the mold 1 externally, an internal heater 40 which heats the resin solution 22 on the inner surface of the rotating mold 1 by spraying hot air on it, and straightening vanes 50 for straightening the flow of the hot air sprayed on the resin solution 22. Since the resin solution 22 on the inner surface of the mold 1 is heated from both inside and outside of the mold 1, the drying efficiency is improved to accelerate drying. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a centrifugal molding machine, a centrifugal molding method, and a molding system for molding a molded product such as an endless belt used in an electrophotographic copying machine or a laser printer.

  A seamless endless belt is used in electrophotographic copying machines and laser printers, and this endless belt is formed by a centrifugal molding machine as shown in FIG. As shown in the figure, this type of centrifugal molding machine includes a mold 1 that is rotated by driving of a driving device 10 and a molding material charging device 20 that causes a resin solution 22 that is a molding material to flow into the rotating mold 1. And an external heating device 30 that heats the rotating mold 1 from the outside (see Patent Documents 1, 2, 3, and 4).

  The mold 1 is formed in a cylindrical shape, and ring-shaped weirs that dam the resin solution 22 are detachably fitted to the inner peripheral surfaces of both open ends, and a molding material is formed on both open ends. The lids penetrating the charging device 20 are detachably fitted. The external heating device 30 is disposed on the side of the mold 1 and indirectly heats the resin solution 22 leveled on the inner peripheral surface of the mold 1 through the peripheral wall of the mold 1, so that the solvent of the resin solution 22 is obtained. Evaporates to dry the resin.

When the endless belt is centrifugally molded by such a centrifugal molding machine, first, the mold 1 is heated by the external heating device 30 while being rotated by the driving device 10, and the resin solution 22 is formed on the rotating die 1 by the molding material. The resin solution 22 is leveled on the inner peripheral surface of the mold 1 by being dropped roughly by the charging device 20, and the resin solution 22 is dried to form an intermediate. When the intermediate is formed in this way, the endless belt can be obtained by allowing the mold 1 to stand for a predetermined time to dry and cure the intermediate, and then removing the mold 1 from the mold 1 and preparing both ends thereof.
Japanese Patent Laid-Open No. 2003-334829 JP 2001-293735 A JP 2001-38749 A JP 2001-38750 A

  The conventional centrifugal molding machine is configured as described above, and the resin solution 22 leveled on the inner peripheral surface of the mold 1 is merely heated indirectly from the outside. There is a big problem of inviting.

  The present invention has been made in view of the above, and an object of the present invention is to provide a centrifugal molding machine, a centrifugal molding method, and a molding system capable of improving the drying efficiency and shortening the drying time.

In the present invention, in order to solve the above problems, a molding material is charged into a rotating mold, and the molding material is pressed against the inner peripheral surface of the mold by centrifugal force to obtain a hollow molded product,
An external heating device that heats the mold from the outside, and a rectifying plate that rectifies (presses) the gas flowing in the rotating mold toward the molding material on the inner peripheral surface of the mold. It is characterized by.
The molding material can be a resin solution, and the molded product can be an endless belt.

In addition, it is equipped with a molding material feeding device that is provided so as to be movable back and forth in the axial direction of the mold, and that injects a liquid molding material into the inner peripheral surface of the rotating mold. It is possible to throw in substantially uniformly.
Furthermore, an internal heating device that is provided so as to be movable back and forth in the axial direction of the mold and that blows hot air onto the molding material pressed against the inner peripheral surface of the rotating mold can be provided.

Further, in the present invention, in order to solve the above-mentioned problem, a method of molding a hollow molded product by the centrifugal molding machine according to any one of claims 1 to 4,
Heating from the outside while rotating the mold, putting the molding material into this rotating mold and pressing the molding material against the inner peripheral surface of the mold, and pressed against the inner peripheral surface of the rotating mold And a step of spraying the molding material while rectifying hot air.

Furthermore, in the present invention, in order to solve the above problems, a system for forming a hollow molded product into a multilayer structure,
The centrifugal molding machine according to any one of claims 1 to 4, which is arranged substantially in a line, and a mold transfer device for transporting a mold among the plurality of centrifugal molding machines. Yes.

  Here, the molding material in the claims may be liquid or powdery. The molded product is mainly a conductive endless belt (seamless belt) or a non-conductive endless belt (seamless belt), but is not limited to this. For example, a pipe, a container, a pulley, a rotor, a tank, or the like may be used. Further, the external heating device, the internal heating device, and the rectifying plate may be any one or more.

  According to the present invention, when the molding material is pressed against the inner peripheral surface of the rotating mold by centrifugal force, the flow straightens the molding material by flowing the gas for drying the molding material to the molding material. Increase material drying efficiency or speed up drying.

In the present invention, when a hollow molded product is subjected to centrifugal molding, first, the mold is heated while being rotated from the outside, and the molding material is put into the mold to be molded on the inner peripheral surface of the mold. Is formed. At this time, it is preferable not to simply input the molding material but to input the substantially quantified molding material substantially uniformly.
Next, hot air is blown to the film-formed molding material, and the hot air flowing in the mold is rectified almost uniformly and blown to the molding material. Goods can be obtained.

  In addition, when centrifugally molding a hollow molded product having a multilayer structure such as two layers, three layers, four layers, and five layers, the above operation is repeated according to the number of layers of the molded product, and the molding material is laminated. A multilayer intermediate may be formed and then cooled and cured.

  ADVANTAGE OF THE INVENTION According to this invention, there exists an effect that the drying efficiency of a molding material can be improved or drying time can be shortened.

  Hereinafter, a preferred embodiment of the first invention of the present invention will be described with reference to the drawings. As shown in FIG. 1, a centrifugal molding machine in the present embodiment includes a mold 1 extending in the depth direction of the figure, A driving device 10 for rotating the mold 1, a molding material charging device 20 for injecting the resin solution 22 into the mold 1, an external heating device 30 for heating the mold 1 from the outside, and heating the mold 1 from the inside. An internal heating device 40 and a rectifying plate 50 for reducing the air resistance inside the mold, and the mold 1, the drive device 10, and the external heating device 30 are installed in a kama chamber (not shown), and the resin solution 22 Thus, a flexible endless belt is centrifugally molded (also referred to as centrifugal casting) into a multilayer structure.

  As shown in FIG. 1, the mold 1 is formed into a cylindrical pipe using steel, stainless steel or the like, and substantially ring-shaped lids are detachably fitted to both open ends. A circular through-hole drilled in the center of each lid is penetrated by the molding material charging device 20. The mold 1 is mirror-finished, fluorine-processed, silicone resin-processed, etc. for facilitating demolding on its inner peripheral surface, and a matte black paint (not shown) is applied to the outer peripheral surface. The paint efficiently absorbs heat from the external heating device 30.

  As shown in FIG. 1, the drive device 10 includes a motor composed of a stepping motor, a servo motor, and the like, a pair of front and rear drive rollers 11 that rotate based on the drive of the motor, and a pair of front and rear adjacent to each drive roller 11. The driven roller 12 includes a plurality of driven rollers 11 and the driven rollers 12 that horizontally mount and support the mold 1.

  The peripheral surfaces of the driving roller 11 and the driven roller 12 are selectively covered with an elastic elastomer made of silicone rubber, fluorine rubber, or the like, and exhibit a vibration damping function of the mold 1 that is in sliding contact with the elastic elastomer. The driven roller 12 is supported so as to be slidable in the horizontal direction in the drawing, and approaches or separates from the side driving roller 11 according to the size of the mold 1.

  The molding material charging device 20 is mounted on a support (not shown) separate from the kama chamber and integrated with the internal heating device 40 and the current plate 50, and the axial direction of the mold 1 (the back direction in the figure). A resin solution 22 that is a molding material is injected into the inner peripheral surface of the mold 1 that moves forward and backward. The support base is formed in, for example, a horizontally long shape, and wheels and legs for movement are disposed at the four corners of the bottom surface, and is disposed adjacent to the hook chamber during centrifugal molding.

  A motor such as a servo motor is installed on the upper surface of the support base, and a ball screw that rotates as the motor is driven is horizontally supported through a bearing. The ball screw is rotated along with the rotation of the ball screw. A stage that travels horizontally in the longitudinal direction while being guided by the guide rail is screwed, and a molding material feeding device 20 is mounted on the stage.

  As shown in FIG. 1, the molding material feeding device 20 is provided with a solution nozzle 21 that can uniformly discharge a precisely quantified resin solution 22, and this elongated solution nozzle 21 is provided at the center of the through-hole of the lid. It penetrates the vicinity. The resin solution 22 is prepared by dissolving a predetermined polymer material (for example, PET, PVDS, PBT, PEN, PES, PAI, etc.) in a solvent. Various additives such as a plasticizer, a colorant, an antistatic agent, an antioxidant, an antioxidant, a reinforcing filler, a conductive agent, a reaction aid, and a reaction inhibitor are appropriately added to the resin solution 22.

  The molding material feeding device 20 having such a configuration is arranged in the axial direction of the mold 1 detachably mounted on the driving device 10 by rotating the ball screw and precisely sliding the stage based on the driving of the motor. Move forwards and backwards and approaches or separates from the mold 1.

  The external heating device 30 includes a heater 31 such as a lamp heater that heats the outer peripheral surface of the opposing mold 1, and a curved reflecting plate that is disposed behind the heater 31 and reflects heat from the heater 31 to the mold 1. 32 and is installed in the interior of the kama chamber and is located at least at one side of the mold 1 with a gap.

  As shown in FIG. 1, the internal heating device 40 is horizontally supported by a hot air source installed in the molding material charging device 20 and a solution nozzle 21 of the molding material charging device 20 via a support, and hot air from the hot air source. And a hot air nozzle 41 for injecting the resin solution 22 into the resin solution 22. The hot air nozzle 41 is formed, for example, in a hollow rod extending in the depth direction of the figure and is positioned obliquely above the solution nozzle 21 and a plurality of injection holes are perforated on the peripheral wall at a predetermined pitch. Hot air (see arrow in FIG. 1), which is a gas, is injected into the mold 1 and the resin solution 22 from the injection holes.

  As shown in the figure, the current plate 50 is curved, for example, using stainless steel or the like so as to have a substantially arc-shaped cross section extending in the depth direction of the figure, and is horizontally placed on the solution nozzle 21 of the molding material charging device 20 via a support. And is located obliquely above the solution nozzle 21. This baffle plate 50 is opposed to the inner peripheral surface of the mold 1 with a space therebetween, makes the hot air flow injected from the hot air nozzle 41 and flowing in the circumferential direction of the mold 1 uniform, and improves the air resistance. It functions to suppress the generation of flow.

  The rectifying plate 50 functions to scrape off the volatile solvent of the resin solution 22 staying on the surface of the endless belt, which is a molded product, by the rectified hot air and centrifugal force. Volatilization of the volatile solvent is promoted by chemical equilibrium, and drying efficiency is improved.

  In the above, when an endless belt having a multilayer structure (three-layer structure in the present embodiment) is subjected to centrifugal molding, first, external heating is performed while rotating the set mold 1 at a high speed in the clockwise direction indicated by the arrow by the driving device 10. Heating is performed from the outside by the radiant heat of the apparatus 30, the molding material charging apparatus 20 is advanced into the rotating lid of the mold 1, and the solution nozzle 21, the internal heating apparatus 40, and the current plate 50 are inserted.

  When the solution nozzle 21, the internal heating device 40, and the rectifying plate 50 are inserted into the rotating mold 1 in this way, the resin solution 22 is injected into the mold 1 by the molding material charging device 20 and the inside of the mold 1 The resin solution 22 is spirally supplied to the peripheral surface, and the resin solution 22 is thinly formed on the inner peripheral surface of the mold 1. At this time, instead of dripping the resin solution 22 roughly, the precisely quantified resin solution 22 is supplied linearly and uniformly.

  Next, the internal heating device 40 is operated to blow hot air on the thinned resin solution 22, and the hot air flowing in the circumferential direction is uniformly rectified and blown by the rectifying plate 50 to evaporate the solvent of the resin solution 22. A cylindrical intermediate is formed dry. After the intermediate structure having a thin single layer structure is formed by drying, the above operation is repeated to sequentially form the resin solution 22 on the inner peripheral surface of the intermediate body, and the thick intermediate body having a multilayer structure (three-layer structure in this embodiment) is laminated. Form. The thickness of the intermediate layer at this time may be the same or different.

  Then, the solution nozzle 21, the internal heating device 40, and the current plate 50 are moved backward from the mold 1, and the mold 1 is left to stand for a predetermined time to dry and cure the multilayer structure intermediate body. If the mold is removed from the mold 1 as a belt, a complete endless belt having a multilayer structure can be obtained.

  According to the above configuration, in addition to heating the resin solution 22 on the inner peripheral surface of the mold 1 from the outside, the resin solution 22 is directly heated from the inside of the mold 1 to prevent temperature unevenness of the mold 1 and to increase the drying speed. Since the drying rate is made uniform, the drying efficiency of the resin solution 22 is remarkably improved, and the resin solution 22 can be dried quickly.

  In addition, the flow straightening plate 50 smoothly moves the air inside the mold along the resin solution 22 and efficiently rectifies it or speeds up the flow rate by the orifice action, thereby preventing the air inside the mold from being disturbed and improving the aerodynamic effect. be able to. Therefore, even when the internal heating device 40 is omitted, drying efficiency can be improved and rapid drying can be expected. In addition, due to the above effects, the molding cycle can be shortened, the resistance value of the endless belt can be reduced and the thickness can be reduced, and an endless belt can be provided at a low cost.

  In addition, the resin solution 22 is flowed roughly, and the resin solution 22 is not leveled depending on the centrifugal force, but a finely quantified fine thread-like resin solution 22 is uniformly supplied to mold the resin solution 22. Since the axial flow range is significantly narrowed, there is no need to fit a heavy weir for resin solution to the mold 1 at all. Accordingly, it is possible to reduce the number of parts and shorten the time for removing and attaching the weir by omitting the weir.

  Further, the endless belt is not formed thickly at one layer, but is gradually formed into a multilayer structure by reducing the thickness per layer, so that the flow range is reduced by reducing the amount of the resin solution 22 required per layer. As a result, drying time and molding time can be shortened.

  Next, FIG. 2 shows a preferred embodiment of the second invention of the present invention. The molding system in this embodiment includes a plurality of centrifugal molding machines arranged side by side along the production line 60. And a mold transfer device 70 for conveying the mold 1 between the plurality of centrifugal molding machines arranged in a horizontal row, and the mold is transferred from the centrifugal molding machine upstream of the production line to the centrifugal molding machine downstream of the production line. The mold 1 is sequentially conveyed by the mold transfer device 70 to manufacture a large number of endless belts having a three-layer structure.

  The production line 60 is divided into the most upstream part 61, the upstream part 62, the middle stream part 63, the downstream part 64, and the most downstream part 65, and at least the most upstream part 61, the upstream part 62, the middle stream part 63, and the downstream part 64. Each will have a Kama room. A plurality of centrifugal molding machines are installed in the kama chamber of the most upstream part 61, two machines are arranged in the kama chamber of the upstream part 62, the middle stream part 63, and the downstream part 64, respectively, and one machine is installed in the most downstream part 65. The

  The hook chamber in the most upstream part 61 functions to preheat the mold 1 before centrifugal molding and contribute to speeding up of the centrifugal molding. The upstream chamber 62 has a function in which the intermediate body of the first layer is centrifugally molded using the mold 1 conveyed from the upstream chamber 61 and the centrifugally molded mold 1 is pre-dried. To do. In addition, in the case chamber of the midstream portion 63, the intermediate layer of the second layer is subjected to centrifugal molding using the die 1 which has been transported after being dried from the upstream portion 62, and this centrifugally molded die 1 is formed. Function to pre-dry.

  The downstream chamber 64 has a mold chamber 1 that is preliminarily dried and conveyed from the midstream section 63. The intermediate layer of the third layer is centrifugally molded, and the centrifugally molded mold 1 is preliminarily prepared. dry. The most downstream part 65 leaves the mold 1 that has been pre-dried and conveyed from the hook chamber of the downstream part 64 to dry and cure the intermediate, and removes the endless belt from the mold 1.

  The mold transfer device 70 includes a motor composed of a servo motor, a ball screw that rotates as the motor is driven, and an uppermost stream portion 61 of the production line 60 that is guided by a guide rail as the ball screw rotates. A traveling platform that travels horizontally (see the arrow in the figure) over the most downstream portion 65 and a pair of cylinders 71 that are mounted side by side on the traveling platform.

Each cylinder 71 is composed of, for example, an air cylinder or a hydraulic cylinder, and a holding claw 73 for holding the lower portion of the mold 1 from below via a roller is provided at the upper end of a piston rod 72 that can move up and down. .
The mold transfer device 70 having such a configuration conveys the two molds 1 from the upstream centrifugal molding machine to the downstream centrifugal molding machine. Other parts are the same as those in the above embodiment, and thus the description thereof is omitted.

  In this embodiment, the same effect as the above-described embodiment can be expected, and a plurality of centrifugal moldings are performed according to the number of layers of the endless belt, instead of molding an endless belt having a multilayer structure by one centrifugal molding machine. It is clear that the molding time can be greatly shortened by arranging the machine and gradually forming the multi-layered endless belt for each layer by the plurality of centrifugal molding machines.

  Specifically, when forming a two-layered endless belt with one centrifugal molding machine of FIG. 3, it took 37 minutes, but with the system of FIG. 2, a three-layered endless belt was molded. In some cases, it can be molded in a short time of about 12 minutes.

  In addition, you may install the metal mold | die 1, the drive device 10, the molding material injection | throwing-in apparatus 20, the external heating apparatus 30, the internal heating apparatus 40, and the baffle plate 50 of the said embodiment in the hook chamber. The mold 1 can be appropriately changed in shape according to the size and length of the molded product. Further, the driven roller 12 may be the driving roller 11, and a driving roll and a driven roll may be used instead of the driving roller 11 and the driven roller 12. Further, a support bar may be attached to the molding material charging device 20, and the internal heating device 40 and the current plate 50 may be supported by the support bar via a support.

  In the above embodiment, the molding material charging device 20 is slid by the rotation of the ball screw based on the motor drive. However, a smooth and quiet belt is used instead of the ball screw, and the belt circulation based on the motor drive is used. The molding material charging device 20 may be slid. Alternatively, the mold 1 may be rotated at a high speed after the solution nozzle 21, the internal heating device 40, and the current plate 50 are inserted into the mold 1 that rotates at a low speed.

  Further, the size and shape of the rectifying plate 50, the distance between the rectifying plate 50 and the inner peripheral surface of the mold 1, and the like can be appropriately adjusted or changed as necessary. Furthermore, in the above-described embodiment, the production line 60 is partitioned into the most upstream part 61, the upstream part 62, the middle stream part 63, the downstream part 64, and the most downstream part 65. However, the production line 60 of the production line 60 depends on the number of layers of the endless belt. The number of partitions can be increased or decreased.

It is explanatory drawing which shows embodiment of the centrifugal molding machine which concerns on this invention, and the centrifugal molding method. It is explanatory drawing which shows embodiment of the centrifugal molding machine which concerns on this invention, and a shaping | molding system. It is explanatory drawing which shows the conventional centrifugal molding machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mold 10 Drive apparatus 20 Molding material input apparatus 21 Solution nozzle 22 Resin solution (molding material)
30 External Heating Device 31 Heater 32 Reflector 40 Internal Heating Device 41 Hot Air Nozzle 50 Rectifying Plate 60 Production Line 61 Uppermost Flow Portion 62 Upstream Portion 63 Middle Flow Portion 64 Downstream Portion 65 Most Downstream Portion 70 Mold Transfer Device 71 Cylinder

Claims (6)

A centrifugal molding machine that inputs a molding material into a rotating mold and presses the molding material against the inner peripheral surface of the mold by centrifugal force to obtain a hollow molded product,
An external heating device that heats the mold from the outside, and a rectifying plate that rectifies the gas flowing inside the rotating mold toward the molding material direction of the inner peripheral surface of the mold. Centrifugal molding machine.   The centrifugal molding machine according to claim 1, wherein the molding material is a resin solution and the molded product is an endless belt.   It is provided so that it can be moved back and forth in the axial direction of the mold, and it is equipped with a molding material charging device that puts a liquid molding material on the inner peripheral surface of the rotating mold. The centrifugal molding machine according to claim 1 or 2, wherein the centrifugal molding machine is put into the machine.   The centrifugal molding according to claim 1, 2 or 3, further comprising an internal heating device that is provided so as to be movable back and forth in the axial direction of the mold and blows hot air onto the molding material pressed against the inner peripheral surface of the rotating mold. Machine. A centrifugal molding method for molding a hollow molded product with the centrifugal molding machine according to claim 1,
Heating from the outside while rotating the mold, putting the molding material into this rotating mold and pressing the molding material against the inner peripheral surface of the mold, and pressed against the inner peripheral surface of the rotating mold And a step of spraying hot air while rectifying hot air on the molding material. A molding system for molding a hollow molded product into a multilayer structure, wherein a mold is placed between the centrifugal molding machine according to any one of claims 1 to 4 and the plurality of centrifugal molding machines. A molding system comprising: a mold transfer device for conveying.

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