Resin molded article having opening and method for producing the same

A resin-molded wheel cap for an automobile having a plurality of openings,

• said resin molded article comprising:
• a central portion into which resin was injected;
• an outer peripheral portion formed at a position outside of said openings;
• and
• bridge portions disposed between said central portion and said outer peripheral portion, each bridge portion serving to separate adjacent openings;
• wherein:
• adjacent bridge portions have the same shape from the view of a designed surface and have different cross-sectional areas;
• the injected synthetic resin is mixed with an inorganic filler;
• and
• at a conjunction portion formed on the outer peripheral portion between adjacent bridge portions, a portion of synthetic resin from the bridge portion of a large cross-section extends into a portion of synthetic resin from the bridge portion of a small cross section.

A resin-molded article having a plurality of openings and produced by injection-molding synthetic resin in a mold,

• said resin-molded article comprising:
• a central portion into which resin was injected;
• an outer peripheral portion formed at a position outside of said openings;
• said outer peripheral portion including a proximal edge surface, a distal edge surface, and a center portion extending between the proximal and distal edge surfaces, the proximal edge surface disposed in closer proximity to an opening than the distal edge surface;
• and,
• bridge portions disposed between said central portion and said outer peripheral portion, each bridge portion serving to separate adjacent openings;
• wherein:
• adjacent bridge portions have the same shape from the view of a designed surface and have different cross-sectional areas, and,
• in the outer peripheral portion, a portion of synthetic resin from a bridge portion of a large cross-section extends into a portion of synthetic resin from a bridge portion of a small cross-section such that synthetic resin in the center portion extends further than synthetic resin in closer proximity to the proximal and distal edge surfaces.

A resin-molded article having a plurality of openings and produced by injection-molding synthetic resin in a mold, the resin-molded article comprising:

• a central portion, into which synthetic resin, which is mixed with an inorganic filler, has been injected to form the article;
• an outer peripheral portion, which is formed at a position outside of the openings, wherein:
• the outer peripheral portion includes a first part, which is relatively near to the center portion, and second part, which is relatively far from the center portion;
• and
• the thickness of the first part is greater than that of the second part;
• and
• the thicknesses of the first part and of the second part gradually decrease as the distance from the center portion increases;
• and
• bridge portions, which are located between the central portion and the outer peripheral portion, each bridge portion being located between a pair of adjacent openings, wherein:
• each bridge portion includes third parts, each of which is adjacent to one of the openings, respectively, and a fourth part, which is separated from the openings by the third parts, respectively, of the same bridge portion;
• the thickness of each third part of each bridge portion is greater than that of the fourth part of the same bridge portion;
• the thicknesses of each third part and of the fourth part gradually decrease as the distance from the nearest of the openings increases;
• and
• the inorganic filler is oriented substantially parallel to the surface of the resin-molded article at a conjunction location, at which different branches of resin flow met and formed a wedge-shaped space during the molding.

A resin-molded article having a plurality of openings and produced by injection-molding synthetic resin in a mold, the resin-molded article comprising:

• a central portion, into which synthetic resin, which is mixed with an inorganic filler, has been injected to form the article;
• an outer peripheral portion, which is formed at a position outside of the openings;
• and
• bridge portions, which are located between the central portion and the outer peripheral portion, each bridge portion being located between a pair of adjacent openings, wherein:
• each bridge portion includes third parts, each of which is adjacent to one of the openings, respectively, and a fourth part, which is separated from the openings by the third parts, respectively, of the same bridge portion;
• the thickness of each third part of each bridge portion is greater than that of the fourth part of the same bridge portion;
• the thicknesses of each third part and of the fourth part gradually decrease as the distance from the nearest of the openings increases;
• and
• the inorganic filler is oriented substantially parallel to the surface of the resin-molded article at a conjunction location, at which different branches of resin flow met and formed a wedge-shaped space during the molding.

A resin-molded article having a plurality of openings and produced by injection-molding synthetic resin in a mold, the resin-molded article comprising:

• a central portion, into which synthetic resin, which is mixed with an inorganic filler, has been injected to form the article;
• an outer peripheral portion, which is formed at a position outside of the openings, wherein:
• the outer peripheral portion includes a first part, which is relatively near to the center portion, and second part, which is relatively far from the center portion;
• and
• the thickness of the first part is greater than that of the second part;
• and
• the thicknesses of the first part and of the second part gradually decrease as the distance from the center portion increases;
• and
• bridge portions, which are located between the central portion and the outer peripheral portion, each bridge portion being located between a pair of adjacent openings, wherein the inorganic filler is oriented substantially parallel to the surface of the resin-molded article at a conjunction location, at which different branches of resin flow met and formed a wedge-shaped space during the molding.