US-20260124796-A1 - FOAM MOLDED PRODUCT, VEHICLE MEMBER AND VEHICLE BACKDOOR

US20260124796A1US 20260124796 A1US20260124796 A1US 20260124796A1US-20260124796-A1

Abstract

A foam molded product is obtained by combining a plurality of foam molded parts that each have a foaming site in which a first skin layer, a foam layer, and a second skin layer are laminated in this order.

Inventors

Shigeya NAKAMURA
Shigeo Suzuki

Assignees

RESONAC CORPORATION

Dates

Publication Date: 20260507
Application Date: 20230929
Priority Date: 20220929

Claims (6)

1 . A foam molded product obtained by combining a plurality of foam molded parts that each have a foaming site in which a first skin layer, a foam layer, and a second skin layer are laminated in this order.
2 . A vehicle member comprising the foam molded product according to claim 1 .
3 . A vehicle backdoor, comprising: an outer panel; and an inner panel provided at a vehicle inner side of the outer panel, wherein at least one of the outer panel or the inner panel includes the foam molded product according to claim 1 .
4 . The vehicle backdoor according to claim 3 , wherein: the outer panel is the foam molded product obtained by combining a first foam molded part and a second foam molded part, and the first foam molded part and the second foam molded part are disposed in a vertical direction.
5 . The vehicle backdoor according to claim 3 , wherein: the inner panel has a window opening, the outer panel is the foam molded product obtained by combining a first foam molded part positioned at an upper portion of the window opening and a second foam molded part positioned at a lower portion of the window opening, and the vehicle backdoor further comprises a door glass covering the window opening.
6 . The vehicle backdoor according to claim 5 , wherein, when a cross section in a thickness direction of the foaming site of the first foam molded part and a cross section in a thickness direction of the foaming site of the second foam molded part are observed, an angle φ formed by a direction orthogonal to the thickness direction of the foaming site of the first form molded part and a direction orthogonal to the thickness direction of the foaming site of the second form molded part shows a relationship of 60° to 90°.

Description

TECHNICAL FIELD The present disclosure relates to a foam molded product, a vehicle member and a vehicle backdoor. BACKGROUND ART Since resin structures are lighter than metal, they are widely used for vehicle structural components, vehicle mounted articles, housings of electronic devices, and the like. Among resin structures, in particular, a resin molded article is lightweight, and when the resin molded article is used for a component of a vehicle such as an automobile, improvement in vehicle fuel efficiency is expected. Thinning of the resin molded article is effective for further reducing the weight of the resin molded article. On the other hand, excessive thinning may cause a decrease in rigidity of the resin molded article. In addition, shapes such as ribs or bosses for securing rigidity may impair the surface appearance of the resin molded article. As a method for reducing the weight of a resin molded article while maintaining rigidity, for example, a foaming molding method as described in Patent Literature 1. In Patent Literature 1, a resin molded article is obtained by injecting a molten resin into a cavity of a molding die formed by a movable die and a fixed die, and then performing a foaming treatment in a state where the movable die is moved to become slightly open (core back). Hereinafter, the resin molded article obtained by performing the foaming treatment may be referred to as a foam molded product. In a case in which the molten resin is injected into the cavity, a portion in contact with a molding die is cooled and solidified to form a film-like skin layer. In this state, when the movable mold is core-backed with respect to the fixed die to expand the volume in the cavity, the molten resin covered with the skin layer is foamed to form a foam layer, and a foam molded product is manufactured. According to the foam molding method, it is possible to thicken the foam molded product while keeping the weight constant by expanding the volume in the cavity, so that it is possible to reduce the weight and improve the rigidity of the foam molded product. Patent Literature 1: Japanese Patent Application Laid-Open (JP-A) No. 2005-238726 SUMMARY OF INVENTION Technical Problem In a case in which the thickness of the foam molded product before foaming (cavity before core back) is the same at all portions, the thickness of the foam molded product changes according to the angle (demolding angle) formed by the opening/closing direction (core back direction) of the molding die and the surface of the foam molded product. Therefore, if the cross-sectional shape of the foam molded product becomes complicated, a portion where the foam molded product cannot be sufficiently thickened may occur depending on the demolding angle, and the strength of the portion may be insufficient. As a response to market demand, cross-sectional shapes of foam molded products have increased in complexity in order to improve design. Specific examples of the foam molded product having a complicated cross-sectional shape include outer panels and inner panels constituting a vehicle backdoor, spoilers, arch moldings, and side panels. Since dies having various demolding angles are used for forming these foam molded products, a portion having insufficient strength tends to easily occur. The present disclosure has been made in view of the above conventional circumstances, and an object of the disclosure is to provide a foam molded product capable of achieving both weight reduction and rigidity improvement, and a vehicle member and a vehicle backdoor using the foam molded product. Solution to Problem Specific means for achieving the above-mentioned problems are as follows. <1> A foam molded product obtained by combining a plurality of foam molded parts that each have a foaming site in which a first skin layer, a foam layer, and a second skin layer are laminated in this order.<2> A vehicle member comprising the foam molded product according to <1>.<3> A vehicle backdoor, comprising: an outer panel; andan inner panel provided at a vehicle inner side of the outer panel, wherein at least one of the outer panel or the inner panel includes the foam molded product according to <1>. <4> The vehicle backdoor according to <3>, wherein: the outer panel is the foam molded product obtained by combining a first foam molded part and a second foam molded part, andthe first foam molded part and the second foam molded part are disposed in a vertical direction. <5> The vehicle backdoor according to <3>, wherein: the inner panel has a window opening,the outer panel is the foam molded product obtained by combining a first foam molded part positioned at an upper portion of the window opening and a second foam molded part positioned at a lower portion of the window opening, andthe vehicle backdoor further comprises a door glass covering the window opening. <6> The vehicle backdoor according to <5>, wherein, when a cross