JPH10235677A - Skin material clamping structure for molding tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To pinch a softened skin material without causing it to be stretched beyond its tolerable extent by supporting plural spheres, in a freely rotating manner, on one peripheral edge part of either of a cavity mold or a core mold and pinching the side edge part of the skin material located between the cavity mold and the core mold together with the spheres at positions corresponding to the spheres on the other peripheral edge part. SOLUTION: A specified quantity of thermoplastic resin 32 which becomes a core material is injected into a gap between a core mold 26 and a skin material 31. The resin 32 injected into a cavity mold 21 and the core mold 26 is pressed by lowering the cavity mold 21 and consequently, the skin material 31 is brought into contact with the cavity face 22 of the cavity mold 21 together with the thermoplastic resin 32 under pressure. In this case, various types of te ion act on the skin material 31 but the skin material 31 is smoothly drawn into the cavity mold 21 as the side edges of the sin material 31 are pinched by the spheres 24 which rotate freely in every direction. Thus it is possible to obtain high quality and highly accurate moldings without damaging the skin material 31, creating abnormal creases or deforming the emboss.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to molding of a skin material required for injection press molding of a multi-layer resin molded product comprising a skin material and a core material such as an instrument panel installed in an automobile. It relates to a clamp structure in a mold.

[0002]

2. Description of the Related Art For example, a resin molded product such as an instrument panel installed in an automobile includes a core material made of a resin such as polypropylene, a skin layer made of, for example, polyvinyl chloride or thermoplastic elastomer, and a foamed polypropylene layer. And a multilayer structure of a surface of the core material and a skin material integrally laminated. A conventional method of manufacturing a resin molded product having such a multilayer structure is shown in FIGS. 9 to 18. First, as shown in FIGS. 9 and 10, the skin material supporting needle 1 is formed in a frame shape, and is appropriately planted around the periphery thereof,
Further, a metal frame 3 for supporting a skin material, which is provided with a positioning hole 2 to be positioned in the metal frame conveying means and a long hole 4 for locking the cylinder rod at an appropriate position, is prepared in advance. The edge of the skin material 10 cut into a shape is pierced into the skin material support needle 1 to be stretched and supported.

Thus, the metal frame 3 is moved into the metal frame 3 by using the positioning pins 6 provided in the metal frame transport means 5 in the positioning holes 2 provided in the metal frame 3 supporting the skin material 10. (See FIG. 11). Next, the metal frame 3 supporting the skin material is sent into the heating furnace 7 by the metal frame transfer means 5 (see FIG. 12), and the skin material 10 supported by the metal frame 3 is heated and softened.

The heat-softened skin material 10 is transferred together with the metal frame 3 by the metal frame transporting means 5 between the cavity die 8 and the core die 9, that is, directly below the cavity die 8 (FIG. 13).
reference). Next, the cylinder rod 11 descends from the cavity mold 8 and is inserted into the elongated hole 4 provided in the metal frame 3.
By rotating by 0 degree, the cylinder rod 11 and the metal frame 3
Are locked (see FIG. 14).

Next, the skin material 10 which has been heated and softened together with the metal frame 3 by the rise of the cylinder rod 11 is placed near the cavity mold 8. At the same time, the frame transporting means 5 retreats (see FIG. 15). At this time, a vacuum force acts on the cavity mold 8, and the core material 9 rises and approaches the cavity mold at the same time as the skin material 10, which has been softened by this, is formed by the adsorbing force of being adsorbed on the cavity surface. A resin 12 serving as a core material is injected between the core mold and the skin material 10 (see FIG. 16).

Next, the core mold 9 is further raised, and the resin 12 is pressed to form the core material 12 integral with the skin material 10 (see FIG. 17). Thereafter, the cylinder rod 11 provided in the cavity mold 8 is inverted by about 90 degrees to release the engagement between the metal frame 3 and the cylinder rod 11, and then the core mold 9 is lowered, so that the skin material 10 and the core material The multilayer resin molded article 13 integrated with the core mold 9 and the metal frame 3
At the same time, and the multilayer resin molded article 13 can be released (see FIG. 18).

[0007]

At the time of forming the conventional multilayer resin molded article formed as described above, the edge of the skin material 10 is pierced into the skin material supporting needle 1 and stretched by the metal frame 3. In this state, the metal frame is softened by heating, and then is shaped by the suction force to the cavity surface by the vacuum force while maintaining the tension support by the skin material supporting needle 1. The edge of the softened skin material 10 supported by is pierced and held by the skin material support needle 1, and the displacement of the skin material 10 is regulated. Therefore, the skin material 10 at the time of suction by the cavity mold is It is difficult to form along the cavity mold surface due to the tension caused by the skin material supporting needles 1, and as a result, it is impossible to perform good-quality molding corresponding to the cavity mold. In particular, in the case of a cavity mold for deep squeezing where the depth (depth) of the mold is large,
When the skin material is sucked into the cavity mold surface, excessive tension acts on the skin material, which causes the skin material to be damaged or the grain applied to the skin material to disappear (texture flow). There were inconveniences such as causing product failures due to such problems as

Further, in the conventional skin material clamping structure, as shown in FIG. 18, before the release of the multilayer resin molded product 13 molded by the pair of cavity mold 8 and the core mold, as shown in FIG. Edge of article 13 (edge of skin material)
Since the metal frame 3 is still fixed by the piercing of the skin material supporting needle 1, it is necessary to remove the metal frame 3 from the multilayer resin molded product 13 after releasing the multilayer resin molded product 13. It was necessary and lacked productivity.

The present invention has been made in view of the above, and provided with a skin material clamping mechanism capable of sandwiching the peripheral portion of the skin material on the peripheral portion of the cavity mold, and heating and softening the skin. When the material is conveyed to the lower part of the cavity mold together with the metal frame, the skin material clamping mechanism works together with the cavity mold to move the periphery of the softened skin material into the cavity by the vacuum suction force of the cavity mold. When it is adsorbed on the surface, it forms a pinching force that does not cause excessive stretching of the softened skin material, and can perform shaping with high quality accuracy according to the shape of the cavity mold. It is intended to provide a clamp structure.

[0010]

In order to achieve the above-mentioned object, the present invention provides a cavity mold and a core for press-forming a core material injected into the back side of the softened skin material in combination with the cavity mold. In a mold having a mold, a plurality of spheres are rotatably supported in a free direction at an appropriate peripheral portion of one of the cavity mold and the core mold, and further, the other of the cavity mold or the core mold is used. At the peripheral portion, a skin material clamp frame is provided corresponding to the sphere, and a skin material clamp frame sandwiching an edge portion of the skin material laid between the cavity mold and the core mold in cooperation with the sphere. It features a clamp structure.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in FIGS.

Numeral 21 is a cavity mold, which is either a vacuum suction mold or a press mold having a plurality of vacuum suction ports (not shown) communicating with the cavity surface. You may. The cavity mold 21 has a cavity surface 22 and the cavity surface 22.
, And a plurality of spheres 24 are arranged along the edge 23 at the edge 23. The sphere 24 is universally rotatably supported by a sphere receiving member 25 fixed to the peripheral portion 23, and the sphere 24 projects downward from the sphere receiving member 25.

Reference numeral 26 denotes a core mold provided below the cavity mold 21 so as to be opposed to the cavity mold 21. A skin material clamp frame facing the spherical body 24 is provided around the core mold 26. 27 are located. The skin material clamping frame 27 is supported by a support 29 erected on a receiving stand 28 receiving the core mold 26 so as to be able to move up and down.
Urged in the push-up direction.

The embodiment of the skin material clamping structure has been described above. Next, a description will be given of a procedure for forming an instrument panel, for example, a part for an automobile, using the above-described skin material clamping structure.

First, as shown in FIG.
In a state where the mold 1 and the core mold 26 are opened, the skin material 31 that has been heated and softened in advance is transferred and placed on the skin material clamp frame 27. Next, the cavity mold 21 is lowered or the core mold 26 is raised, and each sphere 24 disposed on the periphery of the cavity mold 21 and the upper surface of the skin material clamp frame 27 provided on the core mold side. Thus, the edge of the softened skin material 31 is sandwiched (see FIG. 5).

Next, after lowering the cavity mold 21 to a predetermined mold clearance position, a predetermined amount of a thermoplastic resin 32 (polypropylene) to be a core material from a resin injection port (not shown) provided in the core mold 26. Is injected (injected) between the core mold 26 and the skin material 31 (see FIG. 6).

Next, when the cavity mold 21 is further lowered, the thermoplastic resin 32 injected into both molds is pressed,
The skin material 31 which has been subjected to the press pressure is pressed against the cavity surface 22 of the cavity mold 21 together with the thermoplastic resin so as to perform shaping corresponding to the cavity mold. Various tensions act on the depth of the mold. However, this skin material 31
Is sandwiched by the sphere 24 rotating in the free direction, so that the skin material 31 can be smoothly drawn into the cavity mold 21 by the above-mentioned tension (see FIGS. 7 and 8). In other words, since the edge of the skin material 31 is sandwiched by the spheres 24 rotating in the free direction, when a relatively strong tension acts on the skin material 31, the direction in which the strong tension acts is applied. The skin material can be drawn into the cavity surface 2.
2 can be pressed without difficulty, which can damage the skin material 31 or cause abnormal wrinkles,
Alternatively, it is possible to perform shaping with high quality and high molding accuracy without deforming the grain formed in advance on the surface of the skin material (texture flow).

The above-mentioned skin material may be a single-layer sheet made of, for example, a vinyl chloride resin or a thermoplastic elastomer resin, or may be formed by laminating a foamed layer made of, for example, a polypropylene resin on the back surface of the sheet. A skin material having a layer structure may be used, and any skin material can be applied to the present invention. In the above embodiment,
The spherical mold 24 is supported on the cavity mold side, and the skin material clamp frame 27 is provided on the core mold side. Conversely, the skin material clamp frame 27 is provided on the cavity mold side, and the spherical body is supported on the core mold side. It is also possible to make a structure.

[0019]

As described above, according to the present invention, the softened skin material 31 sandwiched between the cavity mold and the core mold is sandwiched by using the sphere 24 which rotates in the free direction. Can be smoothly drawn in the tension direction of the softened skin material 31 located in the inside, and thereby, shaping with high quality and high molding accuracy corresponding to the mold shape of the cavity mold and the core mold becomes possible.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a skin material fixing structure according to the present invention.

FIG. 2 is a bottom perspective view of a cavity mold having a skin material fixing structure according to the present invention.

FIG. 3 is an enlarged sectional view of a main part of a skin material fixing structure according to the present invention.

FIG. 4 is an explanatory view before a skin material clamping by a skin material fixing structure according to the present invention.

FIG. 5 is an explanatory view at the initial stage of a skin material clamp by the skin material fixing structure according to the present invention.

FIG. 6 is an explanatory view at the time of core resin injection by the skin material fixing structure according to the present invention.

FIG. 7 is an explanatory view at the time of pressing by the skin material fixing structure according to the present invention.

FIG. 8 is an explanatory view at the time of pressing completion by the skin material fixing structure according to the present invention.

FIG. 9 is a plan view of a conventional metal frame.

FIG. 10 is a sectional view taken along line BB in FIG. 9;

FIG. 11 is an explanatory view showing a relationship between a metal frame, a metal frame transporting means, and a skin material of a conventional example.

FIG. 12 is an explanatory view at the time of heating and softening a skin material of a conventional example.

FIG. 13 is an explanatory view when a skin material is moved to a position immediately below a conventional cavity mold.

FIG. 14 is an explanatory view of a conventional example at the initial stage of lifting a skin material.

FIG. 15 is an explanatory view of a conventional example at the end of lifting of a skin material.

FIG. 16 is an explanatory view of a conventional example at the time of core material injection.

FIG. 17 is an explanatory diagram at the time of press molding using a conventional cavity mold and a core mold.

FIG. 18 is an explanatory view at the time of completion of molding of a conventional multilayer resin molded product.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 ... Cavity type 22 ... Cavity surface 23 ... Peripheral part 24 ... Sphere 25 ... Sphere receiving member 26 ... Core type 27 ... Skin material clamp frame 28 ... Cradle 29 ... Strut 30 ... Spring means 31 ... Skin material 32 ... Thermoplastic resin

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29K 105: 20 B29L 9:00 31:58

Claims (1)

[Claims] 1. A cavity mold (21) and a core mold (26) for press-forming a core material (32) injected into the back side of a softened skin material (31) in combination with the cavity mold (21). ), A plurality of spheres (24) are rotatably supported in a free direction at an appropriate position on the peripheral edge of one of the cavity mold (21) and the core mold (26). The other peripheral edge of the mold (21) or the core mold (26) is positioned corresponding to the sphere (24), and cooperates with the sphere (24) to form the cavity mold (21) and the core mold ( 26. A skin clamp structure of a molding die, wherein a skin clamp frame (27) for sandwiching an edge portion of a skin material (31) laid between them is provided.