Plastic and nonmetallic article shaping or treating: processes – Mechanical shaping or molding to form or reform shaped article – To produce composite – plural part or multilayered article
Reexamination Certificate
2000-07-11
2002-10-01
Silbaugh, Jan H. (Department: 1732)
Plastic and nonmetallic article shaping or treating: processes
Mechanical shaping or molding to form or reform shaped article
To produce composite, plural part or multilayered article
C264S292000, C264S324000
Reexamination Certificate
active
06458308
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a mold employed in a composite article molding apparatus for molding a composite article, such as a fiber-reinforced plastic article, by a resin transfer molding method (RTM method) which places a woven fabrics in a mold, injects a resin into the mold, and heats the resin for hardening.
2. Description of the Related Art
Various composite articles have become used in all industries including the aircraft industry and the automobile industry in recent years and demand for composite articles is progressively increasing. On the other hand, high manufacturing costs of composite articles are a serious problem obstructing the widespread use of composite articles. Active research and development activities have been made for the reduction of the manufacturing costs of composite articles, and a RTM method has come into wide use in recent years.
A composite article molding method disclosed in JP-B No. 5-14834 bends a prepreg sheet formed by impregnating a woven fabrics with a resin to produce a composite article.
FIG. 7
shows a mold employed in a known composite article molding apparatus which bends a flat woven fabrics to produce a composite article by the RTM method. As shown in
FIG. 7
, the mold consists of a lower half mold
80
and an upper half mold
100
. The lower half mold
80
is formed by placing a core
82
on a base
81
. A woven fabrics
90
not impregnated with a resin is placed on the core
82
, and the upper half mold
100
is joined to the lower half mold
80
to bend the woven fabrics
90
in the shape of a channel. Then, a resin is injected into the mold, and the resin is heated for hardening to obtain a composite article, namely, a fiber-reinforced plastic article.
In producing the composite article by bending the woven fabrics
90
impregnated with the resin by the RTM method using the known mold shown in
FIG. 7
, when the upper half mold
100
is joined to the lower half mold
80
, the upper half mold
100
bends the woven fabrics
90
so as to follow the shape of the core
82
, and compresses the woven fabrics
90
so that the original thickness T(
1
) of the woven fabrics
90
is reduced to a predetermined thickness T(
2
). As shown in
FIG. 8
, flange parts
91
of the woven fabrics
90
are compressed between the upper half mold
100
and the core
82
before the upper wall
101
of the upper half mold
100
comes into contact with a web part
92
of the woven fabrics
90
. Therefore the woven fabrics
90
is unable to slide along the side surfaces of the core
82
when the upper half mold
100
is further lowered to compress the web part
92
of the woven fabrics
90
so that its thickness T(
1
) is reduced to the thickness T(
2
). Consequently, the web part
92
is creased, the strength of the composite article is reduced or the web part
92
cannot be formed in the predetermined thickness T(
2
).
SUMMARY OF THE INVENTION
The present invention has been made to solve such a problem in the prior art and it is therefore an object of the present invention to provide a mold for a composite article molding apparatus, capable of molding a fiber-reinforced plastic article of a satisfactory quality not having any creases by the RTM method.
According to the invention, a mold for molding a composite article comprising a lower half mold having a base and a core mounted on the base a pressure plate placed on a laminated woven fabrics mounted on the core of the lower half mold, having elastic means on an upper surface of the pressure plate for pressing the laminated woven fabrics against the core; and an upper half mold capable of shaping the laminated woven fabrics into a predetermined shape in cooperation with the core of the lower half mold and the pressure plate by compressing the elastic means of the pressure plate to compress the laminated woven fabrics between the pressure plate and the core of the lower half mold.
According to the one feature of the invention, the elastic means comprises a plurality of elastic members arranged on the upper surface of the pressure plate.
According to the another feature of the invention, the elastic means includes a spring.
According to the another feature of the invention, the elastic means includes a hole formed in the upper surface of the pressure plate, a guide pin set upright at a center of a bottom surface of the hole, and a spring placed in the hole and surrounding the guide pin; and the upper half mold is provided with a recess in a portion corresponding to the guide pin to receive the guide pin therein.
According to the another feature of the invention, the upper half mold comprises an outer section and an inner section divided from the outer section through a dividing interface; and the inner section is divided above the pressure plate.
According to the another feature of the invention, the core has side surfaces perpendicular to an upper surface of the base, and the inner section of the upper half mold has an inner surface perpendicular to the upper surface of the base and corresponding to the side surfaces of the core, respectively.
REFERENCES:
patent: 2367822 (1945-01-01), Brown
patent: 2559860 (1951-07-01), Fay
patent: 2559861 (1951-07-01), Fay
patent: 2581222 (1952-01-01), Varner
patent: 2760231 (1956-08-01), Clair
patent: 4149841 (1979-04-01), Patterson
patent: 4222803 (1980-09-01), Kent et al.
patent: 4338070 (1982-07-01), Nava
patent: 4457072 (1984-07-01), Anderson
patent: 4576566 (1986-03-01), Hain
patent: 4735758 (1988-04-01), Larsson et al.
patent: 4755117 (1988-07-01), Onnenberg et al.
patent: 4961700 (1990-10-01), Dunbar
patent: 5164140 (1992-11-01), Siano
patent: 5203940 (1993-04-01), Krone
patent: 5238640 (1993-08-01), Masui et al.
patent: 5393479 (1995-02-01), Nadeau
patent: 5882462 (1999-03-01), Donecker et al.
Fuji Jukogyo Kabushiki Kaisha
Poe Michael I.
Silbaugh Jan H.
Smith , Gambrell & Russell, LLP
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