JP2011194701A - Mold for molding, molding method, and molding molded using the method, - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a molding using at least two kinds of molding resin over the thickness direction.SOLUTION: The present invention relates to a mold 3 manufacturing a core member 1 comprising a first molding body 2 formed of a first resin, and a second molding body 7 formed of a resin with strength different from the first resin and covered on the first molding body 2 in the thickness direction. The mold 3 includes a fixed mold 4 and a movable mold 5 coming close to and separating from the fixed mold 4, with a cavity 30 set between both molds 4, 5. On the cavity 30 side of the fixed mold 4, protrusions 40 are provided, attached with the first molding body 2 molded in advance and extended in the moving direction of the movable mold 5, and a charging port 6 is provided to the movable mold 5 to charge the resin forming the second molding body 7 into the cavity 30. The space M in the thickness direction of the first molding body 2 formed between the first molding body 2 and fixed mold 4 is filled with the resin forming the second molding body 7, by the protrusions 40.

Description

  The present invention relates to a mold for molding, specifically, a mold for molding using foamed resin beads, a molding method, and a molded product molded using the method.

An example of a core material for a seat embedded in a vehicle seat as a molded product will be described. FIG. 7 is a perspective view of a vehicle seat (8) provided with a conventional core material (1b) (1c) (see Patent Document 1). The vehicle seat (8) is configured by connecting the backrest (80) and the seat (81), the first core (1b) is embedded in the seat (81), and the second backrest (80) is second. A core material (1c) is embedded. A load is applied from the occupant to the core material, and in the following description, the direction in which the load is applied to the core material is the thickness direction of the core material. Specifically, in the first core member (1b) in FIG. 7, the arrow D direction is the thickness direction.
Both core materials (1b) and (1c) are made of synthetic resin, and in particular, the first core material (1b) is made of foamed resin beads having both strength and softness, as shown in the plan view of FIG. A metal wire (82) for reinforcement is buried in the part. The metal wire (82) is for reinforcement, and is not limited to being provided at the peripheral portion, but may be provided at, for example, both side portions or the central portion in the horizontal direction.
However, the metal wire (82) is heavier and more expensive than the resin molded product. Accordingly, there has been proposed one in which both sides of the core material are molded with a high-strength resin and the central portion is molded with a low-strength resin so as to reduce the cost while maintaining the strength (see Patent Document 2). ).
FIG. 9 is a perspective view of the core material (1a), and FIG. 10 is a cross-sectional view of the core material (1a) of FIG. The first parts (11) and (11) on both sides of the core material (1a) are molded from high-strength low-magnification foamed resin, and the second part (12), which is the center part of the core material (1a), is low-strength. The parts (11) and (12) are formed integrally with each other.

FIG. 11 is a cross-sectional view of a mold (3) for molding the core material (1a). As is well known, the mold (3) is composed of a fixed mold (4) and a movable mold (5). The cavity (30) between the molds (4) and (5) is filled with foamed resin beads, A core material (1a) is formed. The cavity (30) is divided into a plurality of spaces S1, S2 by the partition plate (31), and the space S1 becomes the first portion (11) and the space S2 becomes the second portion (12). The partition plate (31) is provided in the cavity (30) by the cylinder (32) so as to appear and retract. Resin filling ports (6) and (6a) are connected to the movable mold (5) according to the spaces S1 and S2. Low-magnification foamed resin is supplied from the filling port (6), and high-magnification foamed resin is supplied from the filling port (6a).
At the time of molding, with the partition plate (31) inserted into the cavity (30), the foamed resin beads preformed to a predetermined particle diameter from the filling ports (6) and (6a) are placed in the spaces S1 and S2. Filled. Next, after the partition plate (31) is retracted from the cavity (30) by the cylinder (32), both molds (4) and (5) are heated to fuse the foamed resin beads. Both molds are released from the mold after cooling to obtain a core material (1a) comprising the first part (11) and the second part (12) integrally.

JP-A-6-55566 JP 2006-123732 A

In the conventional core material (1a), since the cavity (30) is partitioned by the partition plate (31) in the direction crossing the thickness direction of the core material (1a), the first part (11) and the second part (12) are It is formed from the same resin throughout its thickness. That is, it is impossible to mold with different types of molding resin across the thickness direction.
However, since the seat core (1a) is located below the occupant's buttocks, the surface of the core (1a) is formed of a low-strength soft resin and the inside is formed of a high-strength resin. There is a demand to secure the overall strength of the core material (1a) while softening the feeling received by the occupant. In the core material (1a) using the conventional mold, the first portion (11) made of a high-strength resin is exposed on the surface, so that such a request cannot be met.
An object of the present invention is to form a molded product such as a core material with at least two types of molding resins in the thickness direction.

Producing a molded product comprising a first molded body formed of a first resin and a second molded body formed of a resin having a strength different from that of the first resin and covering the first molded body. Mold,
A fixed mold and a movable mold that approaches and separates from the fixed mold, and a cavity is provided between both molds.
Provided on the cavity side of one of the molds is a protrusion to which a first molded body molded in advance is attached, the protrusion extending in the moving direction of the movable mold, which is the thickness direction of the first molded body,
One of the molds is provided with a filling port for filling the cavity with the resin that forms the second molded body, and is formed between the first molded body and the mold in which the projections are arranged by the projections. The gap is filled with the resin forming the second molded body.

In order to mold the molded product, first, the movable mold is opened with respect to the fixed mold, and a first molded body molded in advance is attached to a protrusion provided on the cavity side of one of the molds. By the protrusion, a gap is formed in the thickness direction of the first molded body between the first molded body and the mold on which the protrusion is provided.
The movable mold is closed, and the resin forming the second molded body is filled into the cavity from the filling port. The second molded body is formed of a resin having a strength different from that of the first molded body. The resin forming the second molded body fills the gap.
The resin forming the second molded body is covered on the first molded body in the thickness direction of the first molded body, the fixed mold and the movable mold are heated, and the mold is released after cooling. Since the protrusion extends in the moving direction of the movable mold, the protrusion does not hinder when the molded product is taken out along the moving direction of the movable mold.
In this way, the second molded body covers the first molded body in the thickness direction of the first molded body, and the molded product is easily formed with at least two types of molding resins over the thickness direction. be able to.

It is a perspective view of the core material shape | molded using the metal mold | die concerning this invention. It is sectional drawing which fractured | ruptured the core material of FIG. It is sectional drawing of a metal mold | die and shows a mold open state. It is sectional drawing of a metal mold | die and shows a mold clamping state. It is sectional drawing of a metal mold | die and shows a mold open state. (a), (b) is an enlarged view of the B section of FIG. It is a perspective view of the vehicle seat provided with the conventional core material. It is a top view of the 1st core material of FIG. It is a perspective view of the other conventional core material. It is sectional drawing which fractured | ruptured the core material of FIG. It is sectional drawing of the metal mold | die which shape | molds the core material of FIG.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a perspective view of a molded product formed using the mold (3) according to the present example, and FIG. 2 is a cross-sectional view of the molded product of FIG. It is sectional drawing seen. The molded product is a core material (1) for a sheet which is an automobile interior member, and is formed from two types of foamed resins. An occupant's load is applied to the core material (1) in the direction E of FIG. 1, and the direction E is defined as the thickness direction of the core material (1). The molded product molded using the mold and molding method described in this example is not limited to the core material (1) for the sheet.
The core material (1) is formed of a flat plate-like first molded body (2) formed from a high-strength first resin and a low-strength second resin, and the first molded body (2). The second molded body (7) that wraps around the body is integrally formed to form a rectangular parallelepiped shape. That is, the second molded body (7) covers the thickness direction of the first molded body (2). The first resin forming the first molded body (2) is specifically a low-magnification foamed resin bead obtained by foaming the raw material beads 5 to 20 times, and the second molded body (7) The second resin to be formed is a high-magnification foamed resin bead obtained by foaming the raw material beads 15 to 40 times, but is not limited to this foaming ratio. The type of foamed resin will be described later.

On the surface of the second molded body (7), a recessed hole (70) extending to the surface of the first molded body (2) is provided, and the recessed hole (70) is formed by a mold (3 ) Is a trace of the protrusion (40) removed. The surface of the first molded body (2) exposed from the recess hole (70) is provided with a recess (20) for holding the first molded body (2) during molding as described later. belongs to. By providing the hollow hole (70), the first molded body (2) is not exposed from the surface of the core material (1).
3, 4, and 5 are cross-sectional views of the mold (3) for molding the core material (1), FIG. 3 shows the mold opening state, FIG. 4 shows the mold clamping state, and FIG. 5 shows the mold opening. Each state is shown. The mold (3) includes a fixed mold (4) and a movable mold (5) that moves toward and away from the fixed mold (4) in the horizontal direction. Between the fixed mold (4) and the movable mold (5), A cavity (30) which is a space is formed. The fixed mold (4) and the movable mold (5) each form a heating space (45) (55) inside, and the heating space (45) (55) is heated or cooled via a valve (not shown). Water is supplied.
A shaft-like protrusion (40) is provided on the cavity (30) side of the fixed mold (4), that is, the inner side, and the protrusion (40) is movable in the thickness direction of the first molded body (2). It extends in the moving direction of the mold (5). A protrusion (41) that fits into the recess (20) of the first molded body (2) is provided at the tip of the protrusion (40).
The movable mold (5) is provided with a filling port (6) through the heating space (55), and the filling port (6) is connected to the cavity (30). From the filling port (6), the foamed resin beads forming the second molded body (7) are supplied to the cavity (30).

Forming method The forming method of the core material (1) for a sheet is described below.
First, the first molded body (2) is prepared in advance by using another known mold (not shown). As shown in FIG. 3, the movable mold (5) is opened with respect to the fixed mold (4), and the recess (20) of the first molded body (2) is fitted into the projection (41) of the projection (40). A gap M (see FIG. 4) along the thickness direction of the first molded body (2) is formed between the first molded body (2) and the fixed mold (4) provided with the protrusions (40). Is done. Thereafter, as shown in FIG. 4, the movable mold (5) is closed with respect to the fixed mold (4).
From the filling port (6), the foamed resin beads forming the second molded body (7) are supplied to the cavity (30). The foamed resin beads forming the second molded body (7) are covered on the first molded body (2) in the thickness direction of the first molded body (2), and surround the first molded body (2). Then, the gap M is filled.
After filling is completed, heated steam is supplied to the heating spaces (45) and (55). The expanded resin beads forming the second molded body (7) swell. The resin beads are bonded to each other and bonded to the first molded body (2).

Next, cooling water is poured into the heating spaces (45) and (55) to cool the fixed mold (4) and the movable mold (5), and then the movable mold (5) is opened. As shown in FIG. 5, the core (1) in which the second molded body (7) surrounds the first molded body (2) is attached to the protrusion (40). The core material (1) is pushed out by an ejector pin (not shown) provided on the fixed mold (4) to obtain the core material (1). The extrusion direction of the core material (1) is the same as the opening direction of the movable mold (5), and the protrusion (40) does not hinder the extrusion of the core material (1). The trace of the protrusion (40) is the hollow hole (70) of the core material (1).
In this way, the second molded body (7) covers the first molded body (2) in the thickness direction of the first molded body (2), and at least two types of molding are performed over the thickness direction. The core material (1) with a different resin can be easily formed.

If the core material (1) falls easily when the mold is opened, the core material (1) may be damaged. Accordingly, as shown in an enlarged view in FIG. 6 (a), the diameter of the convex portion (41) is enlarged toward the mold release direction of the movable mold (5) (arrow C in FIGS. 6 (a) and (b)). The core material (1) may be hardly separated from the protrusion (40) by providing the undercut effect.
Further, contrary to FIG. 6 (a), as shown in FIG. 6 (b), the diameter of the convex portion (41) is set to the release direction of the movable mold (5) (in FIGS. 6 (a) and (b)). It may be formed so as to shrink along the arrow C) so that the core material (1) can be easily separated from the protrusion (40).
If the horizontal length H of the convex portion (41) is too short, the core material (1) after molding tends to be detached from the convex portion (41), and if it is too long, it is difficult to take out the core material (1). In view of this point, the horizontal length H of the convex portion (41) is assumed to be 3-20 mm. Moreover, although the diameter of a convex part (41) assumes 5-30 mm, it is not limited to this length H and a diameter.
6 (a) and 6 (b), a protrusion (41) is provided on the protrusion (40), and a recess (20) is provided on the first molded body (2). However, instead of this, the protrusion (40) may be provided with a recess (20), and the first molded body (2) may be provided with a protrusion (41).

  The first resin and the second resin, which are foamed resins used for molding, include polystyrene resins, polyolefin resins (for example, polypropylene resins, polyethylene resins), polyester resins (for example, polyethylene terephthalate, polybutylene terephthalate, Polyethylene naphthalate), polycarbonate resins, polylactic acid resins and the like. Among these, it is preferable to use a composite resin of polystyrene and polyethylene.

In this example, as described above, the core material (1) in which the types of at least two molding resins are different can be easily formed in the thickness direction. In addition, there are the following effects.
1. Compared to the conventional mold shown in FIG. 11, the partition plate (31) and the cylinder (32) are unnecessary, so that the mold structure is simplified and the mold cost can be reduced.
2. Since the first molded body (2) is prepared in advance by another mold, the first molded body (2) can be molded into an arbitrary shape. Therefore, the first molded body (2) can be molded into a complicated shape, and can meet a wide range of user requirements.
3. A hollow hole (70) is provided on the surface of the core material (1), whereby the first molded body (2) is not exposed from the core material (1). Since the core material (1) is provided in the vehicle seat, it is possible to soften the feel received by the occupant.

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope thereof. In addition, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims.
The resin forming the first and second molded bodies (2) and (7) is not limited to foamed resin beads, and may be, for example, a meltable thermoplastic resin. In addition, the first molded body (2) is formed from a high-strength resin, and the second molded body (7) is formed from a low-strength resin. The second molded body (7) may be formed from a high-strength resin.
Furthermore, although the protrusion (40) is formed on the fixed mold (4), it may be formed on the movable mold (5). In this case, the first molded body (2) is supported by the movable mold (5). Although the filling port (6) is formed in the movable mold (5), it may be formed in the fixed mold (4).

(1) Core material
(2) First molded body
(3) Mold
(4) Fixed type
(5) Movable type
(6) Filling port
(7) Second molded body

Claims (7)

Producing a molded product comprising a first molded body formed of a first resin and a second molded body formed of a resin having a strength different from that of the first resin and covering the first molded body. Mold,
A fixed mold and a movable mold that approaches and separates from the fixed mold, and a cavity is provided between both molds,
A projection to which a first molded body molded in advance is attached is provided on the cavity side of either mold, and the projection extends in the moving direction of the movable mold, which is the thickness direction of the first molded body. A filling port for filling the cavity with the resin forming the second molded body in the mold of
A mold characterized in that a gap formed by the protrusion between the first molded body and the mold provided with the protrusion is filled with a resin forming the second molded body. The mold according to claim 1, wherein the first molded body is formed from a high-strength resin, and the second molded body is formed from a low-strength resin. The mold according to claim 2, wherein the high-strength resin is a low-magnification foamed resin bead, and the low-strength resin is a high-magnification foamed resin bead. The mold according to any one of claims 1 to 3, wherein a protrusion or a recess that fits into the recess or protrusion of the first molded body is provided at a tip of the protrusion. The mold according to claim 4, wherein the convex portion is formed with an enlarged or reduced diameter along a movable mold release direction. A molded product comprising a first molded body formed of a first resin and a second molded body formed of a resin having a strength different from that of the first resin and covering the first molded body is a mold. A method of manufacturing using
The mold includes a fixed mold and a movable mold that approaches and separates from the fixed mold, a cavity is provided between the fixed mold and the movable mold, and a first molded body that is molded in advance on the cavity side of one of the molds. Is provided, and has a protrusion, the protrusion extends in the moving direction of the movable mold, which is the thickness direction of the first molded body, and fills the cavity with the resin that forms the second molded body in one of the molds Provided,
Opening the movable mold with respect to the fixed mold, attaching the first molded body formed in advance to the protrusion, closing the movable mold with respect to the fixed mold,
The resin forming the second molded body is filled into the cavity from the filling port, and the protrusions are formed along the thickness direction of the first molded body formed between the first molded body and the mold in which the protrusions are arranged. A method comprising a step of filling a gap with the resin. A molded article formed by the method according to claim 6 and having a hollow hole which is a trace of a protrusion formed on a surface thereof.

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