JP3233973B2 - Manufacturing method of molded product with skin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a molded article with a skin in which a terminal portion is wrapped around the skin.

[0002]

2. Description of the Related Art As interior parts such as instrument panels and console boxes of automobiles and other resin products, a molded product 44 with a skin in which a surface of a synthetic resin core material 40 is covered with a skin 34 as shown in FIG. Is often used.
In addition, many of the molded products with the skin are
In order to improve the appearance of 6 and to prevent peeling of the skin at the terminal portion, the terminal portion 46 has a structure in which the terminal portion is wrapped around the skin.

Conventionally, as a method of manufacturing a molded article with a skin in which the terminal portion is wrapped around the skin, there is the following method. First, a flexible skin is arranged in the cavity between the upper and lower molds of the stamping mold, and the skin end is pushed into the cavity by the advance of the slide core, whereby the skin end is stretched into a winding shape. Next, in that state, introduce molten resin between the skin and the lower mold cavity surface,
The molten resin is pressed between the skin and the cavity surface of the lower mold to form a core material having a predetermined shape integrally with the skin (Japanese Patent Laid-Open No. 2-223).
No. 415). In addition, the skin terminal is fixed to the back surface of the core material terminal portion after the molded product is released with an adhesive or the like.

[0004]

However, in the above-mentioned manufacturing method, when the slide core is advanced, the temperature of the skin end is 20 to 6 ° C.
The temperature is as low as 0 ° C., and the elongation of the skin terminal is in a poor state. Therefore, the skin end is forcibly stretched by the slide core and is forcibly wound into the inside of the cavity, and there is a problem that wrinkles or breaks are apt to occur in the skin winding portion.

[0005] In view of the above, the present invention provides a method for producing a molded article with a skin which is less likely to wrinkle or break when the skin is involved.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention is directed to an upper mold having a top surface and an upper mold cavity surface having a side surface bent downward from the periphery of the upper surface. With the skin positioned at the outer peripheral edge of the surface and placing the molten resin on the cavity surface of the lower mold, pressing the molten resin against the back of the skin by clamping the upper and lower molds to form a core material integrally with the skin In the method of manufacturing a molded product, the outer skin is made of a heat-softening material, and an inwardly concave portion is provided at a lower end of a lower mold cavity surface facing a side surface of the upper mold cavity surface, and the upper and lower molds are provided. After the tightening, a heated and pressurized gas is blown from the outside of the mold into the concave portion at the lower end of the lower mold cavity surface to heat and soften the skin located in the concave portion and to wind the skin inside the concave portion.

[0007]

When the heated and pressurized gas is blown, the skin located in the concave portion at the lower end of the lower mold cavity surface is heated and softened by the heated and pressurized gas and easily deformed and stretched. Therefore, when the outer skin is pushed into the concave portion by the heated and pressurized gas and is rolled in, the wrinkle and breakage of the rolled portion are less likely to occur.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings. 1 to 5 are cross-sectional views showing a manufacturing process in one embodiment of the present invention.

First, the type used will be described. The type is
The mold for stamping comprises an upper mold 10 and a lower mold 12. The upper mold 10 has an upper mold cavity surface 17 including an upper surface 14 and a side surface 16 bent downward from the periphery of the upper surface 14. The lower part of the upper die 10 is a slide part 18.

FIG. 6 is a view for explaining the slide portion 18 and shows a cross section taken along line AA of FIG. The slide portion 18 has a four-part structure, and a slide mechanism (not shown) composed of a hydraulic cylinder is provided in a concave portion 20 at the lower end of the lower mold cavity surface described later.
Allows forward and backward movement. The inner end (inner peripheral edge) of the slide portion 18 constitutes the lower end of the side surface 16 of the upper mold cavity surface, and forms the undercut shape in which the lower end is bent inward when moving forward, and releases the undercut shape when moving backward. . When the slide portion 18 advances, the recess 20 in front of the slide portion 18 is not closed.

The slide section 18 is provided with a gas blowing channel 22 and a gas discharging channel 24.

The gas blowing passage 22 has one end open toward the concave portion 20 on the lower mold cavity surface, and the other end connected to a gas supply device (not shown) outside the mold by a gas supply pipe 23. The gas supply device comprises an air compressor. Further, a heating device 26 connected to a power source outside the mold is attached to the gas blowing passage 22. The heating device 26 is for heating the pressurized gas supplied to the gas blowing channel 22 to a predetermined temperature. In the present embodiment, the heating device 26 has a heater in a tubular body having an open end, and a rear end of the tubular body is connected to the gas supply pipe 2.
3 (High heater SAH-2AB440W manufactured by Hibeck) was used.

On the other hand, the gas discharge passage 24 is for discharging the heated and pressurized gas blown into the concave portion 20 at the lower end of the lower mold cavity surface to the outside of the mold after the circulation of the concave portion 20. And when the other end is connected to the pressure regulating valve 28 and reaches a pressure equal to or higher than the set pressure, the pressurized gas is exhausted out of the mold. The gas discharge channel 2
4 need not necessarily be provided at the above-mentioned position, and may be provided at the lower portion of the gas blowing channel 22 so as to communicate outside the mold.

The lower mold 12 has a lower mold cavity surface 31 that is convex toward the upper mold cavity surface 17. At the lower end of the lower mold cavity surface 31, a concave portion 20 which is depressed inward is formed at a position facing the slide portion 18 of the upper mold cavity surface side surface 16. The recess 20 is a space for winding the skin terminal into a winding shape, and has a thickness of a molded product,
The size is determined according to the shape and the like.

One end of the lower mold 12 is provided with the recess 20.
And a gas discharge hole 32 whose other end communicates with a vacuum suction device (not shown) outside the mold. The gas discharge hole 32
Is to discharge the air between the skin and the wall surface of the concave portion 20 when the skin is rolled up so as not to hinder the winding of the skin. Further, the vacuum suction device is provided with
This is for reducing the pressure between the 0 wall surfaces to assist in the winding of the skin, but is not always necessary.

Next, an embodiment of a method for producing a molded article with a skin, which is performed using the mold, will be described. First, as shown in FIG.
In a state where the mold 2 and the lower mold 14 are separated from each other and the mold is opened, a skin 34 is arranged on the cavity surface 17 of the upper mold, and the peripheral edge 36 of the skin 34 is an outer peripheral edge of the upper mold cavity surface 17, in this embodiment. It is located on the lower surface of the slide portion 18. At this time, the slide part 18 is in the forward state, and the tip of the slide part 18 is in contact with the lower part of the skin 34. The supply of the heated and pressurized gas to the slide portion 18 is stopped.

The skin 34 to be used is made of a heat-softening material, and is suitably formed in a predetermined shape by vacuum forming or slash forming in advance. As the heat-softening material, any material having a property of softening by heat may be used, for example, a material made of a thermoplastic synthetic resin sheet such as a vinyl chloride resin, and a soft foam adhered to the back surface of the thermoplastic synthetic resin sheet. And a laminate in which a thermoplastic synthetic resin film and a soft foam are laminated and adhered to a fabric.

On the other hand, a molten resin 38 is arranged on the cavity surface 31 of the lower mold 12. The molten resin 38 becomes a hard core material by cooling and curing, and a thermoplastic synthetic resin such as an acrylonitrile-butadiene-styrene copolymer resin (ABS resin) or a polypropylene resin is used.
The optimum amount of the molten resin 38 differs depending on the thickness of the core material.

Next, as shown in FIG.
And press the molten resin 38 against the back surface of the skin 34. As a result, the molten resin 38 is compressed by the back surface of the skin 34 and the lower cavity surface 31 and flows in the cavity, filling the space between the back surface of the skin 34 and the lower cavity surface 31. At this time, the periphery of the skin 34 passes through the concave portion 20 at the lower end of the lower mold cavity surface and the lower surface of the slide portion 18 and the lower mold 12.
Of the cavity surface.

In this state, pressurized gas is supplied from the gas supply pipe 23 to the heating device 26 of the slide portion 18. The pressurized gas supplied to the heating device 26 is heated to a predetermined temperature by the heater of the heating device 26 to become a heated pressurized gas.
The heated and pressurized gas then passes through the gas blowing channel 22 of the slide portion 18 and is blown from the tip of the slide portion 18 into the concave portion 20 at the lower end of the lower mold cavity surface. Then, after circulating through the concave portion 20, the gas discharge flow path 24
Is discharged out of the mold.

At this time, the pressure regulating valve 28 provided at the end of the gas discharge channel 24 is in an open state. The pressure of the pressurized gas is preferably 1 to 3 kg / cm ^{2 from} the viewpoint of preventing the skin 34 from breaking. The heating of the pressurized gas by the heating device 26 is performed at a temperature at which the skin 34 is softened, and is preferably 150 to 250 ° C., although it depends on the material and thickness of the skin.

The heated and pressurized gas blown into the concave portion 20 is exposed to the skin 34 located in the concave portion 20 during circulation in the concave portion.
Is heated and softened. Then, as shown in FIG. 3, the skin 34 located in the concave portion 20 is rolled into the concave portion 20 while being pushed and extended into the concave portion 20. As a result, the end of the cavity-shaped molten resin 38 is wound around the skin 34.

At this time, the air existing between the skin 34 and the wall surface of the concave portion 20 is discharged out of the mold through the gas discharge hole 32 of the lower mold 12. Further, by the operation of the vacuum suction device connected to the gas discharge hole 32, the pressure between the wall surface of the concave portion 20 and the skin 34 is reduced, and the winding of the skin 34 is assisted.

Thereafter, the blowing of the heated and pressurized gas and the vacuum suction of the lower mold gas discharge hole 32 are stopped, and after the molten resin in the cavity is cooled and hardened, the slide portion 18 is moved outward from the mold as shown in FIG. Retreat. Thereby, the undercut shape on the side surface of the upper mold cavity surface is released. Further, the molten resin in the cavity is cured to become the core material 40.

Next, as shown in FIG. 5, the upper mold 10 and the lower mold 12 are separated, and the molded article 42 attached to the lower mold 12 is released. If the surplus portion of the epidermis 34 is cut off as necessary, and then the end of the epidermis 34 is fixed to the back surface of the core member 40 with an adhesive or the like, FIG.
As a result, a molded article 44 with a skin in which the terminal portion is wrapped around the skin is obtained.

[0026]

According to the present invention, as described above, the skin is heated and softened to form a entangled shape, so that the wrap is forcibly bent and wrinkled, or is forcibly stretched and broken during the entanglement. There is almost no.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an arrangement of a skin and a molten resin according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state at the time of mold clamping in the embodiment.

FIG. 3 is a cross-sectional view showing a state in which heated and pressurized gas is blown in the embodiment.

FIG. 4 is a cross-sectional view illustrating the slide unit in the embodiment when the slide unit is retracted.

FIG. 5 is a cross-sectional view illustrating the molded article in the same example when the mold is released.

FIG. 6 is a sectional view taken along line AA of FIG. 2;

FIG. 7 is a sectional view of a molded article with a skin obtained by carrying out the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 upper die 12 lower die 14 upper surface of upper die cavity surface 16 side surface of upper die cavity surface 18 slide portion 20 concave portion 26 heating device 31 lower die cavity surface 34 skin 36 skin peripheral edge 38 molten resin

Continuation of the front page (56) References JP-A-2-223415 (JP, A) JP-A-59-201814 (JP, A) JP-A-1-258920 (JP, A) JP-A-4-241928 (JP) , A) JP 48-29767 (JP, B1) (58) Fields surveyed (Int. Cl. ⁷ , DB name) B29C 43/18-43/20 B29C 43/32-43/52 B29C 33/12 -33/14 B29C 33/42-33/44

Claims (1)

(57) [Claims] 1. A skin is disposed on an upper mold cavity surface having an upper surface and a side surface bent downward from the upper peripheral edge, and the skin peripheral edge is positioned on the outer peripheral edge of the upper mold cavity surface, and the lower mold cavity surface is disposed. A method for manufacturing a molded article with a skin, in which the molten resin is disposed on the upper and lower molds, and the core is integrally formed with the skin by pressing the molten resin against the back surface of the skin by clamping the upper and lower molds, The upper mold cavity surface is formed of a material, and an inwardly recessed recess is provided at the lower end of the lower mold cavity surface facing the side surface of the upper mold cavity surface. After the upper and lower molds are clamped, a mold is formed at the lower end of the lower mold cavity surface. A method for producing a molded article with a skin, characterized in that a heated and pressurized gas is blown in from outside to heat and soften a skin located in the concave portion and to roll it into the concave portion.