JPH0337930Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention relates to a mold for slush molding, and more specifically, for manufacturing skin bodies of automobile interior parts such as instrument panels and meter hoods. This invention relates to a mold for slush molding.

(Prior art) The above-mentioned slush molding method involves charging powder material into a mold, heating the powder material filled in the mold in advance, and utilizing residual heat held in the mold, or By heating the mold after filling the powder material,
The part of the powder material in contact with the inner surface of the mold is semi-melted, and the powder material is attached to the inner surface of the mold using the adhesiveness generated in the powder material, and then the excess of the filled powder material is melted into the mold. The powder material remaining on the inside surface of the mold is discharged from the mold, and the mold is further heated to completely melt the powder material, and then the mold is cooled and a thin layer is deposited on the inside surface of the mold. This process consists of removing the adhered film from the mold.

Conventional slush molding of skin bodies, such as those used in instrument panels, involves filling, heating, adhering, cooling, and demolding a vinyl chloride resin powder material into a mold obtained by electroforming. For example, in the case of the skin of an instrument panel, there is a large space in the center or near the side edges of the panel due to the location of the instrument or the location of the panel in the car. , it is often necessary to form a notch or the like. The charged powder material also adheres to the inner surface of the mold at unnecessary parts of the skin such as spaces and cutouts, and after the integrally molded skin is removed from the mold, these unnecessary parts are cut out from the skin. The part of the skin that was cut off was disposed of as waste. In order to eliminate the labor involved in this cutting operation and the loss of material, pipes are installed in advance on the side of the mold opposite to the cavity in the mold area, which corresponds to the part of the skin that is clearly unnecessary. Using this pipe, a low-temperature heat medium is supplied to the part, and the unnecessary part of the mold is lowered in temperature compared to the necessary part of the mold which is left as a skin, and the unnecessary part of the mold is removed. A method has been proposed to prevent the adhesion, or conversely, to install pipes that alternately supply high-temperature and low-temperature heat carriers only to the necessary molding portions of the mold skin.
In either case, heat is transferred alternately between the necessary molding portion and the unnecessary molding portion of the mold, which is a major cause of impediments to work efficiency.

(Means for Solving the Problem) This invention relates to a mold for slush molding that forms a necessary molded part of a skin body and an unnecessary molded part that becomes an opening or notch part of the skin body. The cavity surface is divided into areas corresponding to necessary forming and areas corresponding to unnecessary forming, and a recessed part that is one step lower than the cavity surface of the necessary forming part is formed in the entire area corresponding to unnecessary forming, and the entire surface of this recess is In comparison with the cavity surface of the required molding portion, a heat-resistant cover plate that can form an edge step that is approximately equivalent to the thickness of the skin to be molded is used to eliminate the need for a covering mold. It is characterized by forming a cavity in the entire area of the molding equivalent part, which further improves the clarity of the temperature difference on the mold cavity surface between the necessary molding equivalent part and the unnecessary molding equivalent part of the mold, The idea was to further improve work efficiency by clearly demarcating the area where the powder material charged into the mold adheres to the mold cavity surface. Examples will be described using drawings.

(Example) Fig. 1 is a perspective view of the mold for slush molding according to this invention with its cavity section turned down, and Fig. 2 is a perspective view taken along line A-A in Fig. 1. This is an enlarged cross-sectional view. In the figure, 1 is a mold for slush molding, which is formed by nickel electroforming, aluminum precision casting, mold spraying, etc., and this mold has a predetermined skin surface shape. The opening edge of the cavity 2 is integrally formed with an outwardly oriented flange 3, and the cavity 2 has a surface that is indistinguishable from the required molding equivalent part 4 of the skin. The necessary molding equivalent portion 5 is composed of two components that are in charge of molding.

Incidentally, the mold area responsible for this unnecessary molding portion 5 is shown by a group of broken lines in FIG.

Generally, unnecessary molded parts of the skin body are molded into cavity 2.
They tend to concentrate in the area near the opening of the cavity 2 or on the side surface of the cavity 2, but of course the location of the unnecessary molded parts greatly depends and changes depending on the shape of the target skin body.

In this invention, as shown in Fig. 2, a copper pipe 6 is welded to the surface (anti-cavity surface) of the mold 1 on which the part 4 corresponding to the necessary forming of the skin body is located. A fluid supply path is formed to facilitate heating or cooling of the corresponding portion 4.

In this way, the mold 1 is divided into a necessary molding equivalent part 4 and an unnecessary molding equivalent part 5 of the skin body to which the fluid supply path pipe 6 is connected, and among these, the unnecessary molding equivalent part 5 is entirely covered with unnecessary molding parts. A recess 8 is provided that is one step lower than the cavity surface of the molding equivalent part 4, and the entire surface of this recess 8 is covered with a heat-resistant cover plate 10, so that a cavity 7 is formed in the entire area of the unnecessary molding equivalent part 5 of the mold. It is formed.

This heat-resistant cover plate 10 is made of a polyimide resin alone or a polyimide resin mixed with glass fiber (see Figures 3 and 4), or a substrate 17 made of a polyimide resin alone or a polyimide resin mixed with glass fiber. A resin plate or sheet 19 that can particularly effectively prevent the adhesion of powder materials through an adhesive layer 18, such as a rubber adhesive layer, such as a resin plate or sheet made of ultra-high molecular weight polyethylene, fluorocarbon resin, etc. These heat-resistant cover plates 10 are made of a laminated cover plate (see Fig. 5), etc., which are laminated together, and if the recess 8 covered by this cover plate is relatively narrow, the edge part of the recess 8 This cover plate 1 on 15
0 is fitted and locked, and is fixed to the fitting surface with a heat-resistant adhesive or the like (see Fig. 3). Support stands 9 made of foamed blocks made of silicone rubber, polyurethane resin, etc. are arranged at appropriate intervals, and the heat-resistant cover plate 10 is supported at multiple locations on the back side by the support stands 9 to form recesses 8. Cover the entire surface,
The surface of the cover plate 10, which forms a part of the cavity surface of this folding mold, is the required forming portion 4 of the mold 1.
The two sides of the cavity are arranged with an edge step 13 that is high enough to approximately correspond to the desired wall thickness of the skin body 12, and the cover plate 10 is fixed to the recess 8 of the mold with screws 11. Between the head of this screw 11 and the cover plate 10 (see FIG. 4), the fitting surface between the cover plate 10 and the recess 8 (see FIG. 5), and between the cover plate 10 and the support base 9 (see FIG. 4). (See FIG. 4) A silicone caulking material 14 is provided to prevent the occurrence of clogging of the charged powder material in this area as much as possible.

Incidentally, instead of the foam block-shaped support stand 9, a support piece 9' corresponding to this support stand 9 is provided integrally with the mold 1 and protrudes in the recess 8 of the mold, and this group of support pieces 9' is It may also have a structure in which the back surface of the cover plate 10 is supported (see FIG. 5).

(Function) When molding, for example, an automobile instrument panel pad skin using a powder material such as vinyl chloride resin in a slush mold having the above structure, the powder material is first charged into the mold and filled. Then, by using the residual heat of the mold that has been applied in advance using the pipe 6, and by heating after filling the powder material, the powder in the part of the mold that is in contact with the inner surface of the cavity of the necessary molding portion 4 of the mold skin is heated. The material is semi-molten, the adhesive material is adhered to the inner surface of the mold, and the unnecessary portion of the filled powder material that is not semi-molten is discharged from the mold. The powder material located in a layer on the unheated portion of the folding mold corresponding to unnecessary molding is discharged out of the mold without being semi-molten. Thereafter, the mold is further heated to completely melt the semi-molten material adhering to the necessary molding portion 4 of the skin surface of the mold, and then the mold is cooled and the thin wall that adheres to the mold cavity surface is molded. The shaped skin body 12 is demolded. Even if a portion of the extension of the skin body 12 adheres to the unnecessary molding portion 5 of the folding mold 1, this unnecessary burr piece can be easily peeled off.

(Effects of the invention) As detailed above, the mold for molding the skin body is divided into areas corresponding to necessary molding and parts corresponding to unnecessary molding of the skin body, and among these, the entire area corresponding to unnecessary molding is A cavity is formed by covering the cavity surface with a heat-resistant cover plate, thereby forming a heat insulating layer in the unnecessary molding portion of the mold, and forming a heat insulating layer between the two corresponding portions, more specifically, the cavity surface between the two corresponding portions. It is possible to efficiently prevent heat exchange between the two parts, achieve a reliable heat conduction separation effect, and clearly distinguish the layered adhesion of the powder material charged into the mold cavity between the two corresponding parts. This makes it easier to discharge from the mold unnecessary powder material that remains unmelted on the unnecessary molding portion of the mold and the necessary molding portion of the mold. The amount used can be reduced without waste. In addition, a heat-resistant cover plate is provided to form a cavity in a portion of the mold corresponding to unnecessary molding, and an edge step is formed which is higher than the portion of the mold corresponding to necessary molding by an amount approximately corresponding to the thickness of the desired skin body. By doing so, the molding area of the skin body can be made clear, and the opening or notch of the skin body itself can be defined, and a skin body with a uniform thickness can be produced extremely easily. Moreover, the existence of this edge step also makes demolding of the skin body easier. In addition, due to the existence of a cavity and a heat-resistant cover plate that are formed over the entire area of the mold that corresponds to unnecessary molding in order to achieve a remarkable thermal insulation difference, it is possible to make clear edges appear on the completed skin body. This can be expected to have many effects, including the ability to increase product value.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the slush molding die according to this invention, with the cavity section facing down and the fluid supply pipe pipe omitted; FIG. 2 is a perspective view of the die shown in FIG. An enlarged cross-sectional view along the A line,
Figure 3 is an enlarged detailed view of part B in Figure 2;
5 and 5 are diagrams corresponding to FIG. 3 showing another embodiment. In the figure, 1 is a slush molding die, 2 is a cavity, 4 is a necessary molding portion of the skin body, 5 is an unnecessary molding equivalent portion of the skin body, 6 is a pipe, 7 is a cavity portion,
8 is a recessed portion, 10 is a heat-resistant cover plate, and 13 is an edge step.

Claims (1)

[Scope of utility model registration request] In a mold for slush molding that forms a necessary molding part of the skin body and an unnecessary molding part that becomes an opening or notch of the skin body, the cavity surface of the mold is divided into a necessary molding part and an unnecessary molding part, respectively. A recessed part is formed in the entire area of the unnecessary forming part, which is one level lower than the cavity surface of the necessary forming part, and the entire surface of this recess is in contact with the cavity surface of the necessary forming part. In comparison, a heat-resistant cover plate capable of forming an edge step as high as approximately the thickness of the skin for molding purpose was used to form a cavity in the entire area of the covering mold that corresponds to unnecessary molding. A mold for slush molding.