JP2002240102A - Mold for polyhedral resin molded article having hollow part and method for producing the same - Google Patents

Abstract

(57) [Summary] (with correction) [Problem] When the mold opening amount of the fixed mold and the movable mold in the mold opening direction is variable, the mold opening amount in the orthogonal direction can be arbitrarily varied.
When the mold opening amount in the mold opening direction is the maximum, the hermeticity of the cavity is maintained, and when the gas is injected during or after injection of the molten resin, the molten resin does not leak and gas leakage does not occur. Provided are a mold for producing a polyhedral resin molded article having a hollow portion inside a resin and a method for producing the same. A fixed die (2) is provided with a slide core a (6) provided in engagement and a drive unit (9) for controlling sliding of the slide core a, and a movable die (3). Is composed of a block 1 (8) for controlling the amount of movement of the slide core a and a block 2 (7) that slides on a guide 2 (8a) provided on the side of the cavity (10) of the slide core a. A mold structure provided in a fixed mold and a movable mold, wherein a slide core a
Slides according to the guide 1 (7a) of the block 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for a polyhedral molded article having a hollow portion and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, in a method of manufacturing a hollow molded article, a pressurized gas is sealed in a molded article (20) as shown in FIG. There is a method of forming the hollow portion (19). In this method, an insufficient amount of molten resin to fill the cavity is injected and injected into the mold cavity, and then gas is injected from the same injection port to fill the cavity (Japanese Patent Publication No. 57-14968). ). Also, as shown in FIGS. 11 to 13, after injecting an insufficient amount of molten resin (18) into the cavity to fill the inside of the cavity (10), a gas is injected alone or through the gas line (13). (18) while injecting molten resin (1
There is a method of forming a formed body (20) having a hollow portion (19) while retracting the slide core (22) until the solidification of (8) occurs (Japanese Patent Publication No. 7-315). In addition, Tokuho 9
In JP-A-99455, a molten resin is injected into a mold cavity by using a mold capable of reducing or expanding the cavity volume by moving a part of a mold cavity surface, and the molten resin is injected into the mold cavity. Injecting the pressurized fluid while in the molten state, and manufacturing the hollow molded body by expanding the part that can reduce and expand the mold cavity volume while keeping the molten resin in close contact with the mold cavity surface, The mold has an injection port of the pressurized fluid into the molten resin, at least one portion where the cavity volume can be reduced / expanded, and at least one location where the cavity volume cannot be reduced / expanded,
There is a method of forming a molded body (20) having a hollow portion (19) as shown in FIG.

[0003]

However, in the conventional method as described above, as shown in FIGS. 11 to 13, the volume expansion of the fixed mold (2) and the movable mold (3) in the mold opening direction is not possible. Although it is possible, in the direction orthogonal to the mold opening direction, even if the slide core (22) of FIGS. 11 to 13 is stopped before reaching the movable mold surface (3), the hollow core of FIGS. There was a problem that the volume in the orthogonal direction could not be increased even in the molded body (20) having the portion (19).

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and has a fixed mold (2) and a movable mold (3).
By changing the opening amount in the mold opening direction, the opening amount in the orthogonal direction can be arbitrarily changed, and even when the opening amount in the mold opening direction is maximized, the hermeticity in the cavity is maintained. During the injection of the molten resin (18), or when the gas is injected while expanding the volume of the cavity (10) after the injection and injection, the molten resin (18) does not leak or leak. An object of the present invention is to provide a mold for producing a multi-faced resin molded product (27) having a surface (21) and having a hollow portion (19) inside a resin, and a method for producing the same.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, a polyhedral resin molded article having an open surface and a hollow portion inside the resin according to the present invention has been obtained. The molding die is, as described in claim 1,
In a mold for molding a polyhedral resin molded body having an open surface and a hollow portion inside a resin, a slide core a provided in engagement with a fixed mold, and a drive unit that controls sliding of the slide core a The movable mold is provided with a block 1 for controlling the amount of movement of the slide core a and a block for sliding with a guide 2 provided on the cavity side of the slide core a.
2, the cavity is a mold structure provided in the fixed mold and the movable mold. When the movable mold is opened, the slide core a slides according to the guide portion 1 of the block 1. , And the volume in the cavity is enlarged. Further, according to the present invention, a mold for molding a polyhedral resin molded article having an open surface and having a hollow portion inside a resin, as described in claim 2, has a hollow portion inside the resin having the open surface. In a polyhedral resin molding having
A plurality of hollow bodies are formed in a hollow portion inside the resin formed on each surface. Further, according to the present invention, the mold for forming a polyhedral resin molded body having an open surface and having a hollow portion inside a resin according to the present invention has an opening amount (A) of the movable mold as described in claim 3. By the angle (θ) of the guides 1 and 2 of the blocks 1 and 2,
The relationship between the opening amount (A) of the movable mold and the enlargement amount (C) of the side surface of the cavity of the slide core a is represented by the formula I, and the angle (θ) is within the range represented by the formula II. The volume of the core a on the cavity side is variable.

C = tan (90 ° −θ) × A I Formula 0 ° ≦ θ ≦ 85 ° Formula II Further, the metal for molding a multi-faced resin molded article having an open surface and a hollow portion inside the resin according to the present invention. According to a fourth aspect of the present invention, the driving method for controlling the slide of the slide core a is operated by fitting an angular pin. According to the present invention, there is provided a mold for molding a polyhedral resin molded body having an open surface and a hollow portion inside a resin according to the present invention, wherein a block for controlling a moving amount of the slide core a is provided as described in claim 5. A block 2 that slides on a guide portion 1 and a guide portion 2 provided on the cavity side of the slide core a.
Are formed integrally, and the volume inside the cavity is enlarged. Still further, according to the present invention, a mold for molding a polyhedral resin molded body having an open surface and a hollow portion inside a resin according to the present invention controls the amount of movement of the slide core a. A guide block 1 provided on the cavity side of the slide core a and a guide section 1 provided on the cavity side of the slide core a are used. It is characterized by the following. The method for producing a polyhedral resin molded article having an open surface and having a hollow portion inside the resin according to the present invention is described in claim 7.
As described in the above, a method for producing a polyhedral resin molded body using a mold for a resin molded body having the hollow portion, wherein the production method is selected from a gas assist injection molding method and an injection compression molding method It is characterized by the following. Furthermore, the method for producing a polyhedral resin molded article having an open surface and having a hollow portion inside the resin according to the present invention has an open surface and a hollow portion inside the resin as described in claim 8. During or after filling the molten resin into the cavity of the resin molding die, the method of manufacturing the polyhedral resin molded body injects gas into the polyhedral resin molded body from a plurality of gas injection ports provided in the core mold. The present invention is characterized in that the inside volume of the cavity is enlarged and a molded body having a plurality of openings on the open surface side is formed.

[0007]

Hereinafter, the present invention will be described in more detail.

[0008] The resin used in the present invention can be applied as long as it has fluidity during heat molding, and it does not matter whether it is a thermoplastic resin or a thermosetting resin. The thermosetting resin can be easily used by adjusting the curing by the type of catalyst, the amount or the heating temperature. Preferably, a thermoplastic resin which can easily set the forming time of the hollow body having the opening is used. Thermoplastic resins commonly used in general injection molding, injection compression molding, compression molding, extrusion molding, stamping molding, etc. are applied as they are, for example, polyolefin resins such as polyethylene and polypropylene, polystyrene, polycarbonate, acrylonitrile, styrene.
Examples include general thermoplastic resins such as butadiene block copolymers and nylons, and thermoplastic elastomers such as ethylene-propylene block copolymers and styrene-butadiene block copolymers, and polymer alloys thereof. The thermoplastic resin mentioned above includes all of them. Further, in such a thermoplastic resin, various fillers such as talc and glass fiber, pigments, lubricants, antistatic agents, various additives which are generally used such as antioxidants, may be blended. .

The molding device is provided with a device capable of heating the mold and the resin, has a structure capable of expressing the fluidity of the resin, and allowing the cavity volume to be increased by retracting the mold cavity volume during or after filling the resin. A method in which a mold having a plurality of pressurized gas injection nozzles or a plurality of mold gas injection portions corresponding to nozzles provided on a mold surface corresponding to a surface on which an opening of a molded body is provided, and which can be processed into a molded body. Can be used. Preferably, a gas assist injection molding method, an injection compression molding method, and a heat compression molding method are used.

[0010] As shown in Fig. 1, a mechanism for further expanding the cavity volume includes a slide core a (6) provided in engagement with a stationary mold (2), and a movable mold (3). Is provided with a block 1 (8) for adjusting the opening amount of the slide core a (6). The opening amount of the slide core a (6) is determined by the sliding guide portion 2 between the slide core a (6) and the block 1 (8).
The guide part 2 (8a) is determined by the angle of (8a).
Is preferably equal between the slide core a (6) and the block 1 (8), and as the material thereof, a ferrous, non-ferrous or resin-based material can be used. Preferably, it is an iron-based material. Next, the drive unit (9) for sliding the slide core a (6) has an opening amount to be slid according to the angle between the slide core a (6) and the guide unit 2 (8a) provided on the block 1 (8). Any mechanism can be used as long as it follows, and a hydraulic mechanism, a pneumatic mechanism, a spring, or the like can be used as the drive mechanism. Alternatively, the follow-up mechanism of the slide core a (6) by the block 1 (8) and the drive unit (9) is changed by using a fitting jig such as an angular pin when opening and closing the mold.
(6) can follow the opening amount to be slid according to the angle of the guide portion of the fitting jig.

Next, as a mechanism for keeping the inside of the cavity (10) closed, there is a slide core a (6) provided in engagement with the fixed mold (2), and the movable mold (3) has a slide core a (6). Is the guide part 2
A block 2 (7) having the same angle as that of (8a) is provided, and the slide core a (6) follows the opening amount of the slide core a (6).
(6) and block 2 (7) are sliding. The driving mechanism (9) for sliding the slide core a (6) and the slide core a (6) and the sliding mechanism of the block 1 (8) and the block 2 (7) are the slide core a (6) and the slide core a (6). a (6)
The drive unit (9) that slides on the movable mold (3) is provided and the block 1 (8) and the block 2 (7) are provided on the fixed mold (2). It is possible. Also, the guide 1 of block 1 (8) and block 2 (7)
When the angle between (7a) and the guide portion 2 (8a) is the same, the block 1 (8) and the block 2 (7) can be used in an integrated structure. Furthermore, the variable block shown in FIG.
The variable block 1 (23) and the variable block 2 are located at the sliding position between the slide core a (6) and the block 1 (8) as shown by 0
(24) and the variable block 3 (25) and the variable block 4 (26) are set at the sliding portions of the slide core a (6) and the block 2 (7), so that the desired slide core a (6) The amount of enlargement (C) of the cavity side surface can be changed. The variable block shown in FIG. 8 can be used as long as it can be fixed at an angle (θ) in the range of the formula II.

The pressurized gas (17) supplied to the gas injection nozzle (5) shown in FIG. 1 has a heating device (15), and can control injection time, injection pressure, injection start timing, and the like. The material used for the gas injection nozzle (5) can be a ferrous or non-ferrous metal or a ceramic or resin material. In addition, the method of injecting the pressurized gas (17) is preferable because the gas can be injected from the tip and the wall of the gas injection nozzle (5) or from the gap between the core mold (4) and the gas injection nozzle (5). The gap between the core mold (4) and the gas injection nozzle (5) is 100 μm or less. Further, a general gas can be used as the pressurized gas (17) to be used, and examples thereof include air, nitrogen, and carbon dioxide. Preferably, nitrogen gas is used. The lower limit of the pressurized gas (17) to be used varies depending on the molding conditions and the type of resin.
It may be a high-pressure gas of Pa or more, or a low-pressure gas of less than 1 MPa. Preferably it is less than 1 MPa. As a result, the cavity volume can be increased in the mold opening direction and the direction perpendicular to the mold opening direction while maintaining the hermeticity of the cavity (10) with the operation of the movable mold (3). A polyhedral resin molded body having a hollow portion inside the resin is molded in one cycle of an injection molding process.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. 1 to 5, but the present invention is not limited to these embodiments.

FIG. 1 shows a state before the cavity is filled with the molten resin (18), and a mechanism for expanding the cavity volume is provided in engagement with the fixed mold (2). There is a slide core a (6), and the movable mold (3) is provided with a block 1 (8), and the opening amount of the slide core a (6) is adjusted by the angle of the guide 1 (8a). In addition, the drive part (9) is provided in the slide core a (6). The mechanism for keeping the inside of the cavity (10) sealed is a block 2 (7) for the slide core a (6) provided in engagement with the fixed mold (2) and the movable mold (3). Are provided at the angle of the guide portion 2 (7a). The movement amount (C) of the slide core a (6) is equal to the guide portion 1 (8a) and the guide portion 2 (7) shown in FIG.
The relationship between the angle (θ) of a) and the movable mold enlargement amount (A) shown in FIG. 7 is expressed by the formulas I and II.

C = tan (90 ° −θ) × A I Formula 0 ° ≦ θ ≦ 85 ° Formula II FIG. 2 shows a resin filling completed state when the mold mechanism of FIG. 1 is used. FIG. 3 shows that a polyhedral resin molding (27) having an open surface (21) and a hollow portion (19) inside the resin was formed by injecting a pressurized gas (17) after filling the resin from the state of FIG. Immediately after. FIG. 4 shows a state in which the hollow body (1) has an open surface (21) and has an open surface (21) after cooling of the molded body (20) in the state of FIG.
This shows a state in which the multi-sided resin molded article (27) having the item 9) is released from the mold. FIG. 5 shows the final shape of a polyhedral resin molded article (27) having an open surface (21) and having a hollow portion (19) inside the resin.

Next, a method for producing a multi-faced resin molded product (27) having an open surface (21) and having a hollow portion (19) inside the resin will be described with reference to FIG.
4 will be described in more detail.

The mold structure comprises a pair of a movable mold (3) and a fixed mold (2) as shown in FIG. 1, and the fixed mold (2) has a mechanism capable of expanding the cavity volume. There is a slide core a (6) provided in engagement with the
A spring is used as a drive mechanism for the drive unit (9) that slides the slide core a (6). The movable mold (3) and the slide core a (6) provided with the block 1 (8) have an angle of 45 ° between the slide part a (6) and the guide part 1 (8a), and the movable mold (3) and the slide core a ( It is set so that the movement amount in 6) is the same. Next, in the cavity (1
Slide core a (6) movable die (3) block 2 provided in engagement with fixed die (2) to keep
The sliding guide part 2 (7) of (7) is provided at 45 ° like the angle of the block 1 (8). Movable mold (3)
Has a core mold (4) that forms the inner surface of the molded body (20), and has a gas chamber (11) built-in. A pressurized gas (17) is supplied to the gas chamber (11) from outside via a gas supply system (13 to 17). Gas injection nozzle (5) for core mold (4)
Are arranged concavely facing the cavity (10). In the gas injection nozzle (5), a gas supply hole is formed inside the gas injection nozzle (5), and an ejection port for ejecting gas from the side of the gas injection nozzle (5) near the tip of the gas injection nozzle (5) is provided. In addition, pressurized gas (17) enters the cavity (10) through the gap between the core mold (4) and the gas injection nozzle (5).
Is injected. Further, the arrangement of the gas injection nozzle (5) is adjusted according to the desired arrangement of the hollow portion (19).
The gas injection nozzle (5) is incorporated in the core mold (4) at the same position as the center of the hollow part (19). Next, the volume of the cavity (10) before the expansion is 70 × 70 × 5 m.
The mold used was a m × 3 surface and the opening amount (A) of the movable mold after the cavity (10) was enlarged could be changed to 5 mm.

Next, as shown in FIG.
The molten resin (18) is filled in the inside (0), and the pressurized gas (17) is supplied to the gas injection nozzle (5) during and after the filling of the molten resin (18). Then, as shown in FIG.
The movable mold (3) is retracted to increase the internal volume of the cavity (5) and promote the formation of the hollow portion (19). Next, as shown in FIG. 4, after the cooling of the molded body (20) is completed, the movable mold (3) is opened to obtain a multi-faced resin molded body (27).

An injection molding machine with a mold drawing pressure of 110 t was used for molding, and the resin was polystyrene resin (manufactured by Nippon Polystyrene Co., Ltd., trade name: G120K, flexural modulus = 700).
0 MPa) was injection-molded at a resin temperature of 200 ° C. and an injection speed of 50 mm / sec. The mold temperature is 60 ° C. for both the fixed side and the movable side, and the movable mold (3) is retracted after filling the molten resin (18) into the cavity (10), and the molten resin (18) is cooling and solidifying. In this state, the movable mold (3) was retracted at 3 mm / sec, and the opening amount (A) was retracted to 5 mm.

[0020]

As described above, according to the present invention, the structure of the present invention is not limited to the fixed mold in the mold for forming a polyhedral resin molded article having an open surface and a hollow portion inside the resin. A slide core a provided in combination with the slide core a
The movable die is provided with a block 1 that controls the amount of movement of the slide core a and a block 2 that slides with a guide 2 provided on the cavity side of the slide core a. Wherein the cavity is a mold structure provided in the fixed mold and the movable mold,
When the movable mold is opened, the slide core a slides according to the guide portion 1 of the block 1 to form a mold for a polyhedral resin molded body that increases the internal capacity of the cavity. The volume expansion of the resin can be arbitrarily varied, and an excellent effect that a multi-faced resin molded product having an open surface and a hollow portion inside the resin can be easily and efficiently manufactured in one cycle process can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a mold for molding a polyhedral resin molded body having an open surface and a hollow portion inside a resin.

FIG. 2 is a diagram illustrating a state in which a resin is filled in a molding die of a multi-faced resin molded product.

FIG. 3 is a diagram illustrating a state in which a multi-sided resin molded body having an open surface and having a hollow portion inside a resin is molded.

FIG. 4 is a view for explaining mold release of a polyhedral resin molded body having an open surface and having a hollow portion inside the resin.

FIG. 5 is a view for explaining a polyhedral resin molded body having an open surface and having a hollow portion inside the resin.

FIG. 6 is a view illustrating a sliding structure in a direction orthogonal to a mold for molding a polyhedral resin molded product.

FIG. 7 is a view for explaining the formula I and the volume expansion amount of a molded body.

FIG. 8 is a diagram illustrating variable blocks.

FIG. 9 is a diagram illustrating a state where a variable block is set at 45 °.

FIG. 10 is a diagram illustrating a state in which variable blocks 1 to 4 are set in a mold.

FIG. 11 is a diagram illustrating a coreless die.

FIG. 12 is a diagram illustrating a state in which a coreless mold is filled with a resin.

FIG. 13 is a diagram illustrating a molding state of a molded body having a hollow portion.

FIG. 14 is a view illustrating a conventional molded body having a hollow portion.

FIG. 15 is a diagram illustrating another conventional molded body having a hollow portion. 1 ... Injection nozzle 15 ...
Heating device 2 ・ ・ ・ Fixed mold 16 ・ ・ ・
Pressure adjusting valve 3 ... movable mold 17 ...
Pressurized gas 4 ... Core mold 18 ...
Molten resin 5 ・ ・ ・ Gas injection nozzle 19 ・ ・ ・
Hollow part 6 ··· Slide core a 20 ···
Molded body 7 ... Block 2 21 ...
Open surface 7a ・ ・ ・ Guide 1 22 ・ ・ ・
Slide core b 8 ... Block 1 23 ...
Variable block 1 8a ... Guide part 2 24 ...
Variable block 29 Drive unit 24a
Guide 3 10 ・ ・ ・ Cavity 25 ・ ・ ・
Variable block 3 11 ・ ・ ・ Gas chamber 25a ・ ・ ・
Guide part 4 12 ・ ・ ・ Resin injection port 26 ・ ・ ・
Variable block 4 13 ・ ・ ・ Gas line 27 ・ ・ ・
Multi-sided resin molding 14 ・ ・ ・ Control valve

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Koichi Handa Nissan Motor Co., Ltd. 2 at Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture (72) Inventor Nobuyoshi Torii 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Nissan Motor Co., Ltd. 72) Inventor Katsuhiko Suzuki 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd.In-house F-term (reference) 4F202 AG07 AP06 AR07 CA11 CB01 CK06 CK19 CK25 CK54 CK55 CR06 4F206 AG07 AP065 AR075 JA04 JM05 JN14 JN25 JN27 JN

Claims (8)

[Claims] 1. A molding die for a polyhedral resin molded body having an open surface and a hollow portion inside a resin, comprising: a slide core a provided in engagement with a fixed die; A drive unit for controlling the movement is provided, and the movable mold comprises a block 1 for controlling the moving amount of the slide core a and a block 2 for sliding with a guide unit 2 provided on the cavity side of the slide core a, The cavity is a mold structure provided in the fixed mold and the movable mold.When the movable mold is opened, the slide core a slides according to the guide portion 1 of the block 1, and A mold for a polyhedral resin molded body having an open surface and a hollow portion inside the resin, characterized in that the volume in the cavity is enlarged. 2. A multi-faced resin molded product having an open surface and a hollow portion inside a resin, wherein a plurality of hollow bodies are formed in the hollow portion inside the resin formed on each surface. The mold for a multi-faced resin molded product according to claim 1, wherein the mold has an open surface and a hollow portion inside the resin. 3. The slide relative to the opening (A) of the movable mold, based on the opening (A) of the movable mold and the angle (θ) of the guides 1 and 2 of the blocks 1 and 2. The relationship between the expansion amount (C) of the cavity side surface of the core a is represented by the formula I, and the angle (θ) is variable within the range represented by the formula II, and the cavity-side volume of the slide core a is variable. The mold for a multi-faced resin molded product according to claim 1 or 2, wherein the mold has an open surface and a hollow portion inside the resin. C = tan (90 ° −θ) × A I Formula 0 ° ≦ θ ≦ 85 ° Formula II 4. A hollow part having an open surface in a resin having an open surface according to claim 1, wherein the driving method for controlling the sliding of the slide core a is operated by fitting an angular pin. A multi-sided resin molded product mold having 5. A guide unit 1 of a block 1 for controlling the amount of movement of the slide core a and a block 2 sliding on a guide unit 2 provided on a cavity side of the slide core a are integrally formed. 5. The mold for a multi-faced resin molded product having an open surface and a hollow portion inside the resin according to claim 1, wherein the inner volume is expanded. 6. A sliding surface angle of a guide portion 1 of a block 1 for controlling the amount of movement of the slide core a and a sliding surface angle of a block 2 sliding on a guide portion 2 provided on a cavity side of the slide core a. 2. The method according to claim 1, wherein the volume inside the cavity is enlarged by using a possible variable block.
A mold for a polyhedral resin molded body having an open surface as described in 2, 3, 4, and 5, and having a hollow portion inside the resin. 7. A method for producing a resin molded body using a mold for a resin molded body having a hollow portion, wherein the production method is selected from a gas assist injection molding method and an injection compression molding method. A method for producing a polyhedral resin molded article having an open surface and a hollow portion inside the resin. 8. During or after filling the molten resin into the cavity of the resin molding die, gas is injected into the polyhedral resin molded body from a plurality of gas injection ports provided in the core die, and the volume of the cavity is increased. The method for producing a multi-faced resin molded article having an open surface and a hollow inside the resin according to claim 7, wherein a molded article having a plurality of openings on the open surface side is formed.