JP2011143635A - Rubber mold for molding resin, device for molding resin, and method for molding resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber mold for molding a resin capable of reducing a use amount of a rubbery material used for manufacturing the rubber mold for replacement and many kinds, preventing the mold opening of the rubber mold by a simple structure, and mitigating the restriction of a light-generating means, and to provide a device for molding the resin and a method for molding the resin. <P>SOLUTION: The rubber mold 2 for molding the resin comprises a core mold 21 in which a cavity 213 is formed to mold a molded article 6 of a thermoplastic resin 5, and a base mold 22 having a shape in which the core mold 21 is arranged. A mold space 24 which is vacuumed to prevent the mold opening of a plurality of separate mold parts 211 is formed on the contact surface 23 where the core mold 21 mates with the base mold 22. The mold space 24 is formed on the contact surface 23 by alternately repeating the mutual contact part where the core mold 21 contacts with the base mold 22, and the non-contact groove part. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rubber mold for resin molding, a resin molding apparatus, and a resin molding method for obtaining a molded article of a thermoplastic resin.

In general, there are various molding methods such as injection molding, blow molding, extrusion molding, and press molding as methods for obtaining a resin molded product having a predetermined shape using a thermoplastic resin.
On the other hand, for example, in Patent Document 1, when a resin molded product made of a thermoplastic resin is molded by a vacuum casting method using a rubber molding die (rubber die) such as silicone rubber, a molding die is used. On the other hand, a resin molding method capable of selectively heating a thermoplastic resin is disclosed. In this resin molding method, when the molten thermoplastic resin is filled in the cavity of the mold, the thermoplastic resin is irradiated with an electromagnetic wave including a wavelength region of 0.78 to 2 μm through the mold, Due to the difference in physical properties between the rubber constituting the mold and the thermoplastic resin, the thermoplastic resin can be positively heated as compared with the rubber mold.
Further, for example, Patent Document 2 discloses a resin molding apparatus in which a filter that reduces the transmission amount of electromagnetic waves having a wavelength exceeding 2 μm is made of water and the temperature of the filter can be prevented by circulating water. Has been.

JP 2007-216447 A JP 2008-44271 A

However, since a rubber mold such as silicone rubber is made of rubber, it undergoes severe thermal deterioration after being used to mold a thermoplastic resin. For example, it must be replaced when used for several tens of shots (molding). Become. Therefore, the amount of rubber material used for manufacturing the mold is increased.
In order to improve the dimensional accuracy of the molded product, the mold is held for a predetermined time after filling the cavity of the mold with the thermoplastic resin. At this time, it is necessary to prevent the mold from opening, and further measures are required to prevent the mold from being opened with a simple structure.

  The conventional rubber molds are formed in any rectangular shape. On the other hand, there are various shapes such as a rod shape, a column shape, a square shape, and a tube shape from the shape close to the plate shape. Therefore, when an electromagnetic wave including a wavelength region of 0.78 to 2 μm is irradiated to effectively heat the thermoplastic resin filled in the mold, the arrangement space of the electromagnetic wave generating means such as a halogen lamp is restricted. .

  The present invention has been made in view of such conventional problems, and can reduce the amount of rubber material used for the manufacture of replacement and multi-variety rubber molds. A rubber mold for resin molding, a resin molding apparatus, and a resin molding method capable of preventing a structure and obtaining a molded article having a stable dimensional accuracy made of a thermoplastic resin and relaxing a restriction on a light generating means Is to provide.

The first invention is a rubber mold formed by forming a cavity for molding a molded product by filling a thermoplastic resin,
The rubber mold comprises a core mold made of a rubber material and forming the cavity, and a base mold mold made of a rubber material and having a shape in which the core mold is disposed,
The core mold has a circular cross section in the horizontal direction, an elliptical shape, or a polygonal shape similar to these, and the base mold mold corresponds to the shape of the core mold in the horizontal direction. Have a circular ring shape, an elliptical shape, or a polygonal ring shape similar to these,
The core mold is formed by combining a plurality of split mold portions on a split surface for opening the cavity and taking out a molded product, and the split surface is formed in a state in which the core mold is split in the lateral direction. It is in a rubber mold for resin molding characterized by being (claim 1).

According to a second aspect of the present invention, there is provided the rubber mold for resin molding, a light generating means for generating light including a wavelength region of 0.78 to 2 μm, a vacuum means for evacuating the mold space, and the rubber mold. A resin molding apparatus having rotating means for rotating
The mold space is evacuated by the vacuum means to prevent the mold opening, and the rubber mold is turned into the core mold having the circular cross section and the base mold having the circular cross section by the rotating means. It is configured to rotate around the central axis of the mold and to irradiate the light from the outer periphery of the base mold mold by the light generating means to heat the thermoplastic resin filling the cavity. The resin molding apparatus is characterized in that (Claim 5).

According to a third aspect of the invention, there is provided the rubber mold for resin molding, a light generating means for generating light including a wavelength region of 0.78 to 2 μm, a vacuum means for evacuating the mold space, and the rubber mold. A resin molding apparatus having rotating means for rotating the cooling means and cooling means for supplying a cooling fluid into the rubber tube,
The mold space is evacuated by the vacuum means to prevent the mold opening, and the rubber mold is turned into the core mold having the circular cross section and the base mold having the circular cross section by the rotating means. While rotating around the central axis of the mold, the light generating means irradiates the light from the outer periphery of the base mold mold to heat the thermoplastic resin filling the cavity,
After the filling of the thermoplastic resin, the cooling fluid is caused to flow into the rubber tube by the cooling means to cool the thermoplastic resin through the core mold. (6).

According to a fourth aspect of the present invention, there is provided the rubber mold for resin molding, light generating means for generating light including a wavelength region of 0.78 to 2 μm, vacuum means for evacuating the mold space, and the rubber mold And rotating means for rotating
The mold space is evacuated by the vacuum means to prevent the mold opening, and the rubber mold is turned into the core mold having the circular cross section and the base mold having the circular cross section by the rotating means. Resin molding characterized by rotating around the central axis of the mold and irradiating the light from the outer periphery of the base mold mold by the light generating means to heat the thermoplastic resin filling the cavity In the method (claim 7).

According to a fifth aspect of the present invention, there is provided the rubber mold for resin molding, light generating means for generating light including a wavelength region of 0.78 to 2 μm, vacuum means for evacuating the mold space, and the rubber mold Rotating means for rotating the cooling means, and cooling means for supplying a cooling fluid into the rubber tube,
The mold space is evacuated by the vacuum means to prevent the mold opening, and the rubber mold is turned into the core mold having the circular cross section and the base mold having the circular cross section by the rotating means. While rotating around the central axis of the mold, the light generating means irradiates the light from the outer periphery of the base mold mold to heat the thermoplastic resin filling the cavity,
After the filling of the thermoplastic resin, the cooling fluid is caused to flow into the rubber tube by the cooling means to cool the thermoplastic resin through the core mold. (Claim 8).

The rubber mold for resin molding of the first invention comprises a core mold and a base mold mold having a shape in which the core mold is disposed.
The thermoplastic resin can be filled into a cavity formed in a core mold. As a result, only the core mold can be subject to heat degradation due to the filling of the thermoplastic resin, and the base mold mold can be used a larger number of shots (molding) than the core mold. Therefore, it becomes possible to use the base mold mold for a long period of time compared to the core mold, and when replacing a deteriorated core mold, the amount of rubber material newly used for manufacturing the replacement core mold Can be reduced.

In addition, when various types of molded products are molded, multiple types of core molds having cavities matched to the shape of each molded product are prepared, and the base mold can be used in common. Thereby, the usage-amount of the rubber material used for manufacture of a base mold type | mold can be reduced.
Further, by holding the core mold formed of a plurality of divided mold parts in the base mold, it is possible to prevent the plurality of divided mold parts from being opened with a simple structure.

  The core mold has a circular cross section in the horizontal direction, an elliptical shape, or a polygonal shape similar to these, and the base mold mold has a cross section in the horizontal direction corresponding to the shape of the core mold. Has an annular shape, an elliptical shape, or a polygonal ring shape similar to these. As a result, when the thermoplastic resin filling the cavity of the core mold is irradiated with light from the surface of the base mold mold through the base mold mold and the core mold, The rubber mold containing the mold can be rotated around these central axes.

For this reason, the thermoplastic resin filled in the core cavity can be irradiated with light as uniformly as possible from the entire periphery of the base mold. And a thermoplastic resin can be spread quickly and stably to each part in a cavity, and generation | occurrence | production of the filling defect of a thermoplastic resin can be prevented.
Also, the rotation radius when rotating the rubber mold hardly changes, the interference between the light generating means and the rubber mold can be easily avoided, and the light generation to irradiate the thermoplastic resin in the cavity The means can be placed as close as possible to the rubber mold. Therefore, it is possible to relax restrictions on the arrangement space of the light generating means.

  Therefore, according to the rubber mold for resin molding of the first invention, it is possible to reduce the amount of the rubber material used for manufacturing the rubber mold for replacement and for a variety of products, and the rubber mold can be easily opened. Therefore, it is possible to obtain a molded article having a stable dimensional accuracy made of a thermoplastic resin, and to ease the restrictions on the light generating means.

In the resin molding apparatus of the second invention and the resin molding method of the fourth invention, when the light is emitted to the rubber mold by the light generating means, the core mold having a circular cross section by the rotating means. And rotating around the central axis of the base mold having an annular cross section. Thereby, the rotation radius when rotating the rubber mold hardly changes, the interference between the light generating means and the rubber mold can be easily avoided, and the light that irradiates the thermoplastic resin in the cavity with light. The generating means can be arranged as close as possible to the rubber mold. Therefore, it is possible to relax the restriction on the arrangement position of the light generating means.
In addition, in the second invention and the fourth invention, the same effect as the first invention can be obtained.

  Therefore, according to the resin molding apparatus of the second invention and the resin molding method of the fourth invention, as in the invention of the rubber mold for resin molding, it is used for manufacturing a rubber mold for replacement and various types. The amount of rubber material used can be reduced, the mold opening of the rubber mold can be prevented by a simple structure, a molded product with a stable dimensional accuracy made of thermoplastic resin can be obtained, and the light generation means are restricted Can be relaxed.

In the resin molding apparatus of the third invention and the resin molding method of the fifth invention, after filling the cavity with the thermoplastic resin, a cooling fluid is caused to flow in the rubber tube by the cooling means, and the core mold Cool down. Thereby, cooling of the thermoplastic resin in a molten state can be accelerated | stimulated, and the time which shape | molds the molded article of a thermoplastic resin can be shortened.
In addition, in the third and fifth inventions, the same effects as those of the first invention can be obtained.

  Therefore, in the resin molding apparatus of the third invention and the resin molding method of the fifth invention, as in the invention of the rubber mold for resin molding, the rubber used for the production of the rubber mold for replacement and various types The amount of material used can be reduced, the rubber mold can be prevented from opening with a simple structure, and a molded product with a stable dimensional accuracy made of a thermoplastic resin can be obtained. Can be relaxed.

Cross-sectional explanatory drawing in the state which looked at the resin molding apparatus in Example 1 from upper direction. Cross-sectional explanatory drawing which shows the resin molding apparatus in the state which evacuates the inside of a cavity and type | mold space in Example 1 from the side. Sectional explanatory drawing which shows the state which looked at the resin molding apparatus of Example 1 in the state which irradiates light to the thermoplastic resin in a cavity by the light generation means from the side. Sectional explanatory drawing which shows the base mold type | mold which forms type | mold space in Example 1 in the state seen from the side. Explanatory drawing which shows the molded article shape | molded in the rubber die in Example 1 in the state seen from the side. 3 is a graph showing the light transmittance of silicone rubber in Example 1. FIG. Sectional explanatory drawing which shows the state which looked at the resin molding apparatus of the state which evacuates the inside of a cavity and type | mold space in Example 2 from the side. Sectional explanatory drawing which shows the state which wound the rubber tube around the core type | mold outer periphery in Example 2. FIG. Cross-sectional explanatory drawing which shows the state which looked at the resin molding apparatus of Example 2 in the state which irradiates light to the thermoplastic resin in a cavity by the light generation means from the side.

A preferred embodiment in the first to fifth inventions described above will be described.
In the first invention, the light (electromagnetic wave) irradiated to the thermoplastic resin through the rubber mold includes not only light in the wavelength region of 0.78 to 2 μm but also light in other regions. It may be. In this case, it is preferable that the light irradiated to the thermoplastic resin through the rubber mold includes more light in a region having a wavelength of 0.78 to 2 μm than light in other regions.

Further, the plurality of split mold parts can be a pair of split mold parts, and can also be three or more split mold parts. Further, the split mold part does not need to be split into symmetrical shapes, and can be split by various split surfaces (split surfaces such as wavy, uneven, and saw-shaped).
In the second to fifth inventions, not only one light generating means but also a plurality of light generating means can be used. That is, depending on the shape of the molded product (or cavity), it may be preferable to irradiate light from both sides or from the top, bottom, left, and right.

Moreover, as a thermoplastic resin used for light irradiation shaping | molding in the 1st-5th invention, what absorbs light (electromagnetic wave) and a heating is accelerated | stimulated can be used.
The thermoplastic resin is not particularly limited as long as it contains a polymer having thermoplasticity, ABS resin (acrylonitrile / butadiene / styrene resin), ASA resin (acrylate / styrene / acrylonitrile resin), AES resin (acrylonitrile).・ Ethylene-propylene-diene / styrene resin) rubber reinforced styrene resin, polystyrene, styrene / acrylonitrile copolymer, styrene / maleic anhydride copolymer, styrene such as (meth) acrylic acid ester / styrene copolymer Resins, olefin resins such as polyethylene and polypropylene, cyclic olefin resins, acrylic resins, polycarbonate resins, polyester resins, polyamide resins, vinyl chloride resins, polyarylate resins, polyacetal resins, polyphenylene ethers Tellurium resin, polyphenylene sulfide resin, fluorine resin, imide resin, ketone resin, sulfone resin, urethane resin, polyvinyl acetate, polyethylene oxide, polyvinyl alcohol, polyvinyl ether, polyvinyl butyral, phenoxy resin, photosensitive resin, liquid crystal Examples thereof include polymers and biodegradable plastics. These can be used alone or in combination of two or more.

  Among the above thermoplastic resins, rubber-reinforced styrene resins, olefin resins, acrylic resins, polyester resins, polyamide resins, polyester resins and polycarbonate resins are suitable as thermoplastic resins used for light irradiation molding. Examples include alloys of alloys, rubber-reinforced styrene resins and polycarbonate resins, alloys of rubber-reinforced styrene resins and polyester resins.

Furthermore, the thermoplastic resin is preferably an amorphous thermoplastic resin.
The cooling rate of the thermoplastic resin is slower than that of the mold because the rubber mold is made of rubber. For this reason, the crystallinity of the thermoplastic resin may increase during cooling, which may reduce the dimensional accuracy of the molded product or the impact resistance of the molded product. On the other hand, by making the thermoplastic resin an amorphous thermoplastic resin, it may be possible to prevent a decrease in dimensional accuracy and a decrease in impact resistance of the molded product.

The rubber mold is preferably made of silicone rubber.
In this case, it is easy to produce the rubber mold, and the thermoplastic resin can be selectively heated by the light including the wavelength region of 0.78 to 2 μm with little heating of the rubber mold.
Moreover, it is preferable that the hardness of a silicone rubber is 25-80 in a JIS-A standard measurement.

In the second to fifth inventions, the reason why the thermoplastic resin can be selectively heated by the light including the wavelength region of 0.78 to 2 μm as compared with the rubber mold is considered as follows. .
That is, the light with a wavelength region of 0.78 to 2 μm irradiated on the surface of the rubber mold has a higher ratio of being transmitted through the rubber mold and absorbed by the thermoplastic resin than the ratio absorbed by the rubber mold. I think. For this reason, it is considered that light energy including light having a wavelength region of 0.78 to 2 μm is preferentially absorbed by the thermoplastic resin, and the thermoplastic resin can be selectively heated.
In the core mold constituting the rubber molds of the first to fifth inventions, the cavity can be easily formed by transferring the shape of the sample (master model) of the molded product. Therefore, it is easy to form a cavity in the core mold.

  In the first invention, at the contact surface where the core mold and the base mold mold are combined, at least one of the core mold and the base mold mold prevents the plurality of split mold portions from opening. Therefore, it is preferable that a mold space to be in a vacuum state is formed, and the mold space is formed by alternately forming contact portions where the molds are in contact with each other and groove portions which are not in contact with each other on the contact surface ( Claim 2).

  In this case, when the thermoplastic resin is filled into the cavity of the core mold constituting the rubber mold, the mold space is evacuated. And while making the inside of a type | mold space into a vacuum state, the force which presses a core type | mold can be made to act on a base mold type | mold by making the pressure around a base mold type | mold into a state more than atmospheric pressure. Thereby, it is possible to prevent the split surfaces of the plurality of split mold parts from being opened, and the plurality of split mold parts can be clamped by the base mold. Therefore, even when the pressure at the time of filling the thermoplastic resin is applied to the plurality of divided mold parts, the plurality of divided mold parts can be prevented from opening the mold.

  Further, the mold space is formed by repeatedly forming contact portions where the core mold and the base mold die are in contact with each other and groove portions which are not in contact with each other on the contact surface. Thereby, the pressure applied from the base mold to the split mold part constituting the core mold can be made as uniform as possible, and the mold opening can be prevented stably. Therefore, the mold opening of the rubber mold can be prevented by a simple structure, and the dimensional accuracy of the molded product obtained by cooling the thermoplastic resin in the cavity can be improved.

Further, the core mold is formed in a columnar shape, and the base mold mold is formed in a bottomed cross-sectional annular shape in which a housing hole for housing the core mold is formed, and the core It is preferable that a rubber tube made of a rubber material is spirally wound around the outer periphery of the mold, and the core mold around which the rubber tube is wound is accommodated in the accommodation hole.
In this case, it is possible to prevent the plurality of split mold parts constituting the core mold from opening the mold by tightening the plurality of split mold parts by the force for winding the rubber tube.

In this case, after filling the core-shaped cavity with the thermoplastic resin, the thermoplastic resin is cooled by flowing a fluid such as air, water, or silicone oil into the rubber tube to form a molded product. Can be obtained.
Further, by changing the outer diameter of the rubber tube to be used, various core molds having different outer diameters can be used with respect to the common base mold mold.
The rubber tube can be made of the same rubber material as that constituting the rubber mold or a rubber material having the same properties as the rubber material constituting the rubber mold.

Further, the rubber tube is spirally wound closely in the axial direction of the core mold, and the plurality of split molds are formed by gaps surrounded by the outer periphery of the core mold and the outer periphery of the rubber tube. In order to prevent mold opening of the part, a mold space to be in a vacuum state is preferably formed (Claim 4).
In this case, a contact portion that contacts the outer periphery of the core mold may be formed by the outer periphery of the rubber tube, and a groove portion that does not contact the outer periphery of the core mold may be formed by a gap between the outer periphery of the rubber tube. it can. And by making the inside of the mold space by the groove part into a vacuum state, it can be held by the base mold and the plurality of divided mold parts can be clamped.
Moreover, the force which winds a rubber tube can clamp a some division | segmentation type | mold part, and can assist mold clamping. In addition, the mold clamping can be further assisted by pressurizing the inside of the rubber tube with a fluid such as air.

  Further, a rubber spacer can be disposed adjacent to the core mold in the accommodation hole of the base mold mold. Also in this case, similarly to the case of the rubber tube, by changing the thickness of the spacer, the core molds having different sizes can be arranged in the base mold.

Hereinafter, embodiments of a rubber mold for resin molding, a resin molding apparatus, and a resin molding method of the present invention will be described with reference to the drawings.
Example 1
As shown in FIGS. 1 and 2, the rubber mold 2 for resin molding of this example is formed by filling a thermoplastic resin 5 and forming a cavity 213 for molding a molded product 6.
The rubber mold 2 includes a core mold 21 made of a rubber material and forming a cavity 213, and a base mold mold 22 made of a rubber material and having a shape in which the core mold 21 is disposed. The core mold 21 has a circular cross section in the lateral direction W, and the base mold mold 22 has a circular cross section in the horizontal direction W corresponding to the shape of the core mold 21. Yes.

  As shown in FIG. 2, the core mold 21 is formed by combining a plurality of split mold portions 211 on a split surface 212 for opening the cavity 213 and taking out the molded product 6. It is formed in a state of being divided in the horizontal direction W. In the contact surface 23 where the core mold 21 and the base mold 22 are combined, a mold space 24 is formed in a vacuum state in order to prevent the plurality of split mold portions 211 from opening. The mold space 24 is formed by alternately forming contact portions 241 where the core mold 21 and the base mold 22 are in contact with each other and groove portions 242 which are not in contact with each other on the contact surface 23.

  As shown in FIGS. 1 to 3, the resin molding apparatus 1 of this example includes a rubber mold 2 for resin molding, and a light generating means 3 that generates light (electromagnetic waves) X including a wavelength region of 0.78 to 2 μm. And a vacuum means 41 for evacuating the mold space 24 and a rotating means 42 for rotating the rubber mold 2. The mold space 24 is evacuated by the vacuum means 41 to prevent mold opening, and the rubber mold 2 is turned into the core mold 21 having a circular cross section by the rotating means 42 and the base mold mold 22 having an annular cross section. The thermoplastic resin 5 filled in the cavity 213 is heated by irradiating light X from the outer periphery of the base mold 22 by the light generating means 3.

Hereinafter, the rubber mold 2 for resin molding, the resin molding apparatus 1 and the resin molding method of this example will be described in detail with reference to FIGS.
As shown in FIGS. 1 and 2, the core mold 21 and the base mold 22 constituting the resin mold rubber mold 2 of this example are made of silicone rubber as a rubber material. The rubber mold 2 is produced by placing a master model (handmade product etc.) of a molded product 6 to be molded in a liquid silicone rubber, curing the silicone rubber, and taking out the master model from the cured silicone rubber. can do. Further, since the rubber mold 2 is made of rubber, it is possible to easily and arbitrarily form a dividing surface (parting surface) 212 for performing mold opening when taking out the molded product 6 after molding.

  In this example, as the thermoplastic resin 5, an ABS resin that is an amorphous thermoplastic resin and a rubber-modified thermoplastic resin is used. As the thermoplastic resin 5 in this example, a particulate resin and a molten resin are used. That is, the cavity 213 of the core mold 21 of this example is first filled with the particulate thermoplastic resin 5, heated and melted, and then filled with the molten thermoplastic resin 5.

  As shown in FIGS. 3 and 4, the core mold 21 of this example is formed in a cylindrical shape, and the base mold mold 22 is a bottomed cross-sectional circle in which a receiving hole 220 for receiving the core mold 21 is formed. It is formed in a ring shape. The base mold 22 is formed in a container shape with a bottom 221 and an annular side wall 222 standing from the edge of the bottom 221. A lid 223 is disposed on the upper end surface of the side wall 222 of the base mold 22, and the accommodation hole 220 in the base mold 22 is closed by the lid 223. The lid 223 can be reinforced with a metal member such as a reinforcement pipe or a reinforcement plate.

  The mold space 24 of this example is formed on the inner surface of the lattice-shaped groove portion 242 formed in the vertical direction and the transverse direction W perpendicular to the inner periphery of the base mold die 22 and the bottom portion 221 of the base mold die 22. A grid-like groove portion 242 is formed on the opposite side. And the contact part 241 is formed as the remaining part left between the groove parts 242 formed in the grid | lattice form. A communication space 224 that communicates with the mold space 24 is also formed between the core mold 21 and the lid portion 223.

  The light generating means 3 of this example is configured using a halogen lamp 31 that emits light X including a wavelength region of 0.78 to 2 μm (corresponding to a near infrared wavelength region). As the halogen lamp 31, a lamp having a light intensity peak in a wavelength range of 0.78 to 2 μm (in this example, about 0.9 μm) was used.

As shown in FIG. 1, the light generating means 3 of this example distributes a halogen lamp (light source) 31 that emits light (electromagnetic wave) X including a wavelength region of 0.78 to 2 μm, and light X emitted from the halogen lamp 31. A reflector 32 that reflects light and a relay reflector 33 that further reflects the light X reflected from the reflector 32 and guides it to the rubber mold 2 are provided. The relay reflecting mirror 33 is configured to be swingable up and down and left and right, and its reflecting surface faces a direction C2 inclined with respect to a rotation center axis C1 for rotating the relay reflecting mirror 33. .
Then, the light generating means 3 distributes and reflects the light X reflected from the reflector 32 to the relay reflecting mirror 33, and rotates the relay reflecting mirror 33 around the rotation center axis C1. The light X reflected by the mirror 33 is configured to irradiate the rubber mold 2 so as to draw a circle.

The rotation means 42 of this example is configured by a rotation base 421 on which the rubber mold 2 is placed and a drive motor that rotationally drives the rotation base 421.
The light generating means 3 of this example is disposed on both sides in the lateral direction W with respect to the rubber mold 2 placed on the rotating base 421, and irradiates the rubber mold 2 with light X from both sides in the lateral direction W. It is configured to do. And the relay reflecting mirror 33 which comprises each light generation means 3 can be arrange | positioned facing the outer periphery of the rubber mold 2.

As shown in FIGS. 2 and 3, an injection port 214 for injecting the thermoplastic resin 5 into the cavity 213 by the injection nozzle 43 is formed at the upper position of the split surface 212 in the pair of split mold portions 211. . The inlet 214 is formed across both the pair of split mold portions 211. Then, the thermoplastic resin 5 is injected into the cavity 213 from the injection port 214, and the molded product molded into the injection port 214 can be taken out integrally with the molded product 6 of the thermoplastic resin 5 molded into the cavity 213. it can.
The vacuum means 41 of this example is constituted by a vacuum pump, and a suction port 225 connected to the vacuum pump is formed below the base mold 22.

  The injection nozzle 43 of this example is arranged at the injection port 214 in the core mold 21 so as to inject the molten thermoplastic resin 5 into the cavity 213 at a predetermined pressure (for example, a pressure of 0.2 to 10 MPa). It is configured. In this example, an injection nozzle for introducing the particulate thermoplastic resin 5 into the cavity 213 can also be arranged at the injection port 214 of the core mold 21 (not shown).

Next, the resin molding method using the rubber mold 2 for resin molding and the operational effects of this example will be described.
First, as shown in FIG. 4, the core mold 21 is disposed in the accommodation hole 220 of the base mold mold 22, and as shown in FIG. 2, the vacuum means 41 is connected to the suction port 225 of the base mold mold 22. The space 24 is evacuated. When the mold space 24 is in a vacuum state, the pressure around the base mold die 22 can be applied to the base mold die 22 by applying the pressure around the base mold die 22 to the atmospheric pressure state. it can. Thereby, it is possible to prevent the split surfaces 212 of the plurality of split mold parts 211 from being opened, and the base mold 22 can clamp the plurality of split mold parts 211. And even when the pressure at the time of filling the thermoplastic resin 5 is applied to the pair of split mold portions 211, the pair of split mold portions 211 can be prevented from opening the mold.

  Next, although not shown in the drawing, a charging nozzle is disposed at the injection port 214 of the core mold 21, and the particulate thermoplastic resin 5 is charged into the cavity 213 from the charging nozzle. Next, as shown in FIG. 1 and FIG. 3, the light generating means 3 irradiates light X including a wavelength region of 0.78 to 2 μm from the surface of the base mold die 22 to form a thermoplastic resin in a particle state in the cavity 213. 5 is heated to melt. At this time, a space not filled with the thermoplastic resin 5 is formed in the cavity 213.

Further, when heating is performed by the light generating means 3, the rubber mold 2 is rotated around the central axis of the core mold 21 having a circular cross section and the base mold mold 22 having a circular cross section by the rotating means 42. Rotate.
Therefore, the light X can be irradiated as uniformly as possible from the entire circumference of the base mold 22 to the thermoplastic resin 5 filled in the cavity 213 of the core mold 21. Then, the thermoplastic resin 5 can be quickly and stably distributed to each part in the cavity 213, and the occurrence of poor filling of the thermoplastic resin 5 can be prevented.

  Further, when the rubber mold 2 is rotated, the radius of rotation hardly changes, the interference between the light generating means 3 and the rubber mold 2 can be easily avoided, and the thermoplastic resin 5 in the cavity 213 can be avoided. The light generating means 3 for irradiating the light X can be disposed as close as possible to the rubber mold 2. Therefore, the restriction on the arrangement space of the light generating means 3 can be relaxed.

  Further, the mold space 24 is formed by alternately forming contact portions 241 where the core mold 21 and the base mold 22 are in contact with each other and groove portions 242 which are not in contact with each other on the contact surface 23. As a result, the pressure applied from the base mold 22 to the split mold portion 211 constituting the core mold 21 can be made as uniform as possible, and the mold opening can be prevented stably. Therefore, the mold opening of the rubber mold 2 can be prevented by a simple structure, and the dimensional accuracy of the molded product 6 obtained by cooling the thermoplastic resin 5 in the cavity 213 can be improved.

  Next, the unfilled space left in the cavity 213 is filled with the molten thermoplastic resin 5. Thereby, the filling amount of the molten thermoplastic resin 5 to be newly filled can be reduced, and the filling pressure of the molten thermoplastic resin 5 can be lowered. Therefore, the mold opening of the pair of split mold portions 211 can be more effectively prevented, and the molded product 6 of the thermoplastic resin 5 having excellent dimensional accuracy can be molded.

  Further, when the light X including the wavelength region of 0.78 to 2 μm is irradiated from the surface of the base mold die 22, the physical properties of the rubber material and the thermoplastic resin 5 constituting the core die 21 and the base mold die 22. Due to the difference, the thermoplastic resin 5 can be selectively heated compared to the core mold 21 and the base mold mold 22 (the amount of heating of the thermoplastic resin 5 can be increased compared to the rubber mold 2). . Thereby, the temperature rise of the core mold 21 and the base mold mold 22 can be suppressed, and the thermoplastic resin 5 can be effectively heated. Therefore, when the molded product 6 of the thermoplastic resin 5 is molded, the thermal degradation of the core mold 21 and the base mold mold 22 can be effectively prevented.

  Here, FIG. 6 shows the light X in each silicone rubber with the wavelength (nm) on the horizontal axis and the transmittance (%) of the light X on the vertical axis for transparent silicone rubber and translucent silicone rubber. It is a graph which shows the transmittance | permeability of. In the figure, it can be seen that each silicone rubber transmits light X having a wavelength between 200 and 2200 (nm). For this reason, when near infrared light having a wavelength region is irradiated on the surface of the rubber mold 2 made of silicone rubber, most of the near infrared light can be transmitted through the rubber mold 2 and absorbed by the thermoplastic resin 5.

Next, as shown in FIG. 5, after filling the thermoplastic resin 5, the heating by the light generating means 3 is stopped, and the thermoplastic resin 5 heated and melted in the cavity 213 of the core mold 21 is cooled, The molded product 6 can be molded by solidifying the thermoplastic resin 5.
The molded product 6 in the cavity 213 can be taken out by taking out the core mold 21 from the base mold 22 and opening a pair of split mold portions 211 constituting the core mold 21.

As described above, the rubber mold 2 for resin molding of this example includes the core mold 21 and the base mold mold 22 having a shape in which the core mold 21 is disposed.
The thermoplastic resin 5 can be filled in the cavity 213 formed in the core mold 21. As a result, only the core mold 21 can be subject to heat degradation due to the filling of the thermoplastic resin 5, and the base mold 22 can be used more times than the core mold 21. . Therefore, it becomes possible to use the base mold die 22 for a long period of time compared to the core die 21, and when replacing the deteriorated core die 21, a rubber that is newly used for manufacturing the replacement core die 21. The amount of material used can be reduced.
In addition, when various types of molded products 6 are molded, a multi-type core die 21 having a cavity 213 matched to the shape of each molded product 6 is prepared, and the base mold die 22 is used in common. Can do. Thereby, the usage-amount of the rubber material used for manufacture of the base mold type | mold 22 can be reduced.

  Therefore, according to the rubber mold 2 for resin molding of the first invention, it is possible to reduce the amount of the rubber material used for manufacturing the rubber mold 2 for replacement and various types. Opening can be prevented by a simple structure, and a molded product 6 having a stable dimensional accuracy made of the thermoplastic resin 5 can be obtained, and restrictions on the light generating means 3 can be relaxed.

(Example 2)
In this example, as shown in FIG. 7, the rubber tube 25 is spirally wound around the outer periphery of the core mold 21, and the core mold 21 wound with the rubber tube 25 is accommodated in the accommodation hole 220 of the base mold mold 22. This is an example of the rubber mold 2.
Also in this example, the core mold 21 is formed in a cylindrical shape, and the base mold mold 22 is formed in a bottomed cross-sectional annular shape in which a housing hole 220 for housing the core mold 21 is formed. . The rubber tube 25 is wound in a spiral manner in close contact with the axial direction of the core mold 21.
As shown in FIG. 9, the resin molding apparatus 1 of this example includes a cooling unit 44 that supplies air A as a cooling fluid into the rubber tube 25.

  In this example, as shown in FIG. 7, a mold that is in a vacuum state in order to prevent the molds of the plurality of divided mold parts 211 from being opened by a gap surrounded by the outer periphery of the core mold 21 and the outer periphery of the rubber tube 25. A space 24 can be formed. A contact portion 241 that contacts the outer periphery of the core die 21 is formed by the outer periphery of the rubber tube 25, and a groove portion 242 that does not contact the outer periphery of the core die 21 is formed by a gap between the outer periphery of the rubber tube 25. Can do. Further, the contact portion 241 and the groove portion 242 can be formed in a spiral shape, and these can be formed as uniformly as possible with respect to the entire circumference of the core mold 21.

  Then, as shown in FIG. 7, by vacuuming the mold space 24 by the groove 242, the plurality of divided mold parts 211 can be clamped while being held by the base mold 22. Further, the plurality of split mold portions 211 can be clamped by the force for winding the rubber tube 25 to assist the mold clamping. Further, the mold clamping can be further assisted by pressurizing the inside of the rubber tube 25 with air A.

  Further, as shown in FIG. 9, after the thermoplastic resin 5 in the cavity 213 of the core mold 21 is heated and melted by the light generating means 3, the air A is caused to flow into the rubber tube 25 by the cooling means 44. The molded product 6 can be obtained by cooling the thermoplastic resin 5 through the core mold 21. Therefore, the time until the molded product 6 of the thermoplastic resin 5 after cooling can be taken out can be shortened, and the molding cycle of the molded product 6 can be shortened. In addition to the air A, the thermoplastic resin 5 heated by flowing water, silicone oil or the like can be cooled in the rubber tube 25.

Further, in this example, various core molds 21 having different outer diameters can be used for the common base mold 22 by changing the outer diameter of the rubber tube 25 to be used. The rubber tube 25 is made of the same silicone rubber as the rubber material constituting the rubber mold 2.
Also in this example, other configurations such as the rubber mold 2 and the resin molding apparatus 1 are the same as those in the first embodiment, and the same effects as those in the first embodiment can be obtained.

DESCRIPTION OF SYMBOLS 1 Resin molding apparatus 2 Rubber mold for resin molding 21 Core mold 211 Split mold part 212 Split surface 213 Cavity 22 Base mold mold 220 Accommodating hole 23 Contact surface 24 Mold space 241 Contact part 242 Groove part 25 Rubber tube 3 Light generating means 41 Vacuum means 42 Rotating means 43 Injection nozzle 44 Cooling means 5 Thermoplastic resin 6 Molded product A Air

Claims (8)

A rubber mold formed by forming a cavity for molding a molded product by filling a thermoplastic resin,
The rubber mold comprises a core mold made of a rubber material and forming the cavity, and a base mold mold made of a rubber material and having a shape in which the core mold is disposed,
The core mold has a circular cross section in the horizontal direction, an elliptical shape, or a polygonal shape similar to these, and the base mold mold corresponds to the shape of the core mold in the horizontal direction. Have a circular ring shape, an elliptical shape, or a polygonal ring shape similar to these,
The core mold is formed by combining a plurality of split mold portions on a split surface for opening the cavity and taking out a molded product, and the split surface is formed in a state in which the core mold is split in the lateral direction. A rubber mold for resin molding, characterized in that 2. The rubber mold for resin molding according to claim 1, wherein a contact surface where the core mold and the base mold mold are combined is divided into at least one of the core mold and the base mold mold by dividing the plurality of divisions. A mold space is formed in a vacuum state to prevent the mold part from opening,
A rubber mold for resin molding, wherein the mold space is formed by alternately and alternately forming contact portions where the molds are in contact with each other and groove portions which are not in contact with each other on the contact surface. The rubber mold for resin molding according to claim 1 or 2, wherein the core mold is formed in a columnar shape, and the base mold mold has a bottomed hole in which a housing hole for housing the core mold is formed. The cross section is formed in an annular shape,
A rubber tube made of a rubber material is spirally wound around the outer periphery of the core type,
A rubber mold for resin molding, wherein the core mold around which the rubber tube is wound is housed in the housing hole. The rubber mold for resin molding according to claim 3, wherein the rubber tube is spirally wound closely in the axial direction of the core mold,
A mold space that is in a vacuum state is formed by a gap surrounded by the outer periphery of the core mold and the outer periphery of the rubber tube so as to prevent mold opening of the plurality of divided mold parts. Rubber mold for resin molding. The rubber mold for resin molding according to claim 2 or 4, a light generating means for generating light including a wavelength region of 0.78 to 2 µm, a vacuum means for evacuating the mold space, and the rubber A resin molding apparatus having rotating means for rotating the mold,
The mold space is evacuated by the vacuum means to prevent the mold opening, and the rubber mold is turned into the core mold having the circular cross section and the base mold having the circular cross section by the rotating means. It is configured to rotate around the central axis of the mold and to irradiate the light from the outer periphery of the base mold mold by the light generating means to heat the thermoplastic resin filling the cavity. A resin molding device. A rubber mold for resin molding according to claim 4, a light generating means for generating light including a wavelength region of 0.78 to 2 μm, a vacuum means for evacuating the mold space, and the rubber mold A resin molding apparatus having a rotating means for rotating, and a cooling means for supplying a cooling fluid into the rubber tube,
The mold space is evacuated by the vacuum means to prevent the mold opening, and the rubber mold is turned into the core mold having the circular cross section and the base mold having the circular cross section by the rotating means. While rotating around the central axis of the mold, the light generating means irradiates the light from the outer periphery of the base mold mold to heat the thermoplastic resin filling the cavity,
After the filling of the thermoplastic resin, the cooling fluid is caused to flow into the rubber tube by the cooling means to cool the thermoplastic resin through the core mold. Resin molding equipment. The rubber mold for resin molding according to claim 2 or 4, a light generating means for generating light including a wavelength region of 0.78 to 2 µm, a vacuum means for evacuating the mold space, and the rubber Using rotating means for rotating the mold,
The mold space is evacuated by the vacuum means to prevent the mold opening, and the rubber mold is turned into the core mold having the circular cross section and the base mold having the circular cross section by the rotating means. Resin molding characterized by rotating around the central axis of the mold and irradiating the light from the outer periphery of the base mold mold by the light generating means to heat the thermoplastic resin filling the cavity Method. A rubber mold for resin molding according to claim 4, a light generating means for generating light including a wavelength region of 0.78 to 2 μm, a vacuum means for evacuating the mold space, and the rubber mold Using a rotating means for rotating and a cooling means for supplying a cooling fluid into the rubber tube,
The mold space is evacuated by the vacuum means to prevent the mold opening, and the rubber mold is turned into the core mold having the circular cross section and the base mold having the circular cross section by the rotating means. While rotating around the central axis of the mold, the light generating means irradiates the light from the outer periphery of the base mold mold to heat the thermoplastic resin filling the cavity,
After the filling of the thermoplastic resin, the cooling fluid is caused to flow into the rubber tube by the cooling means to cool the thermoplastic resin through the core mold. .

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