Metal founding – Process – Shaping liquid metal against a forming surface
Reexamination Certificate
2004-02-02
2004-09-14
Lin, Kuang Y. (Department: 1725)
Metal founding
Process
Shaping liquid metal against a forming surface
C164S312000, C164S900000
Reexamination Certificate
active
06789603
ABSTRACT:
FIELD OF THE INVENTION
The invention generally relates to a method and apparatus for manufacturing metallic parts, and more particularly to a method and apparatus for manufacturing metallic parts by a process involving injection of a melted metal into a mold.
BACKGROUND OF THE INVENTION
One method used to produce molded metallic parts from melted metal is by die casting. One die casting system and method are described in U.S. Pat. No. 5,983,976, hereby incorporated by reference. Die casting methods inject liquid metal into a mold.
Semi-solid methods for producing molded metallic parts differ from the die casting methods by injection molding a metal in its semi-solid state rather than in its liquid state. Semi-solid injection molding systems and methods are disclosed in U.S. Pat. Nos. 5,836,372 and 6,135,196, both of which are incorporated by reference herein.
The die casting system described in U.S. Pat. No. 5,983,976 is illustrated in FIG.
1
. The system
10
includes an injection molding apparatus
10
and a mold
14
. Apparatus
10
is preferably mounted on wheels and/or rails (not shown) such that it may be retracted from the mold
14
after each injection step and advanced toward the mold
14
before each injection step by a motor or hydraulics (not shown).
The apparatus
10
contains a melt feeder
23
provided with at least one heating element
25
disposed around its outer periphery. The feeder
23
is mounted on an inclined temperature-controlled metering barrel
30
such that the liquid metal flows from the feeder
23
to barrel
30
by way of gravity through a feeder conduit or port
27
. A ram or metering rod
32
is arranged coaxially with the barrel
30
and extends along the center axis of the barrel
30
. The ram
32
is controlled by motor
33
for axial movement in both retracting and advancing directions along the barrel
30
to meter the amount of metal leaving barrel
30
and for rotation around its own axis if stirring of the melted metal is desired inside barrel
30
. The motor
33
is mounted on the upper end of barrel
30
.
The metering barrel
30
is mounted over an injection or accumulation barrel
50
. The metering barrel
30
is mounted above the injection barrel
50
such that it is inclined with respect to the horizontal direction. An inlet port or conduit
37
is located between the barrels through which the metal flows between the metering barrel
30
and injection barrel
50
.
The injection barrel
50
contains a plunger or piston
45
and an injection nozzle
57
. The plunger
45
contains a seal, such as O-ring(s)
41
, to form an air tight seal with the inner surface of the injection chamber
50
. The plunger
45
is advanced in the injection chamber
50
by a motor or hydraulics (not shown) to inject the liquid or semi-solid metal from the injection chamber
50
through the nozzle
57
into a mold cavity
13
in mold
14
. The apparatus
10
produces high quality injection molded parts at a low cost. The remaining elements shown in
FIG. 1
are described in U.S. Pat. No. 5,983,976.
However, the present inventor has noted several problems with the apparatus
10
which increase the apparatus maintenance costs and down time. First, the liquid metal in the metering barrel
30
seeps into the motor
33
, which requires increased maintenance of the motor. Second, the bolts which connect barrel
30
to barrel
50
need frequent replacement due to the stress placed on the bolts by the weight of the metering barrel.
SUMMARY OF THE INVENTION
According to one preferred aspect of the present invention, there is provided an injection molding apparatus, comprising an injection chamber located in a first plane and mounted over a base of the apparatus, a metering chamber located at least partially above the first plane, and in fluid communication with the injection chamber, a metering element located in the metering chamber, a first driving mechanism which moves the metering element, wherein the first driving mechanism is connected to the metering chamber, and a melt feeder in fluid communication with the metering chamber. A fill line of the melt feeder is located below a first opening between the metering chamber and the first driving mechanism, and/or the melt feeder is mounted to the base of the apparatus.
According to another preferred aspect of the present invention, there is provided a metal injection molding apparatus, comprising a first means for housing metal to be injected into a mold, the first means located a first plane and mounted over a base of the apparatus, a second means for housing the metal to be metered, the second means located at least partially above the first plane, a third means for metering metal into the first means, a fourth means for moving the third means, and a fifth means for melting the metal provided into the second means, such that melted metal in the fifth means is located below a first opening between the second means and the fourth means and/or the fifth means is mounted to the base of the apparatus.
According to another preferred aspect of the present invention, there is provided a metal injection molding method, comprising providing solid metal into a melt feeder, melting the solid metal into a liquid state, such that fill line of the liquid metal is below a first opening between an inclined metering chamber and a first driving mechanism, providing the liquid metal into the inclined metering chamber containing the first driving mechanism attached to an upper portion of the metering chamber, metering the metal from the metering chamber into an injection chamber located below a lower portion of the metering chamber, and injecting the metal from the injection chamber into a mold.
REFERENCES:
patent: 2386966 (1945-10-01), MacMillin
patent: 2505540 (1950-04-01), Goldhard
patent: 2529146 (1950-11-01), Feitl
patent: 2785448 (1957-03-01), Hodler
patent: 3048892 (1962-08-01), Davis, Jr. et al.
patent: 3106002 (1963-10-01), Bauer
patent: 3123845 (1964-03-01), Madwed
patent: 3172174 (1965-03-01), Johnson
patent: 3189945 (1965-06-01), Strauss
patent: 3201836 (1965-08-01), Nyselius
patent: 3254377 (1966-06-01), Morton
patent: 3268960 (1966-08-01), Morton
patent: 3270378 (1966-09-01), Madwed
patent: 3270383 (1966-09-01), Hall et al.
patent: 3286960 (1966-11-01), Douglas et al.
patent: 3319702 (1967-05-01), Hartwig et al.
patent: 3344848 (1967-10-01), Hall et al.
patent: 3447593 (1969-06-01), Nyselius et al.
patent: 3474854 (1969-10-01), Mace
patent: 3491827 (1970-01-01), Mace
patent: 3529814 (1970-09-01), Werner
patent: 3550207 (1970-12-01), Struss
patent: 3693702 (1972-09-01), Piekenbrink et al.
patent: 3773873 (1973-11-01), Spaak et al.
patent: 3810505 (1974-05-01), Cross
patent: 3814170 (1974-06-01), Kahn
patent: 3874207 (1975-04-01), Lemelson
patent: 3893792 (1975-07-01), Laczko
patent: 3902544 (1975-09-01), Flemings et al.
patent: 3936298 (1976-02-01), Mehrabian et al.
patent: 3976118 (1976-08-01), Kahn
patent: 4049040 (1977-09-01), Lynch
patent: 4088178 (1978-05-01), Ueno et al.
patent: 4168789 (1979-09-01), Deshais et al.
patent: 4212625 (1980-07-01), Shutt
patent: 4287935 (1981-09-01), Ueno et al.
patent: 4330026 (1982-05-01), Fink
patent: 4347889 (1982-09-01), Komatsu et al.
patent: 4387834 (1983-06-01), Bishop
patent: 4434839 (1984-03-01), Vogel
patent: 4436140 (1984-03-01), Ebisawa et al.
patent: 4473103 (1984-09-01), Kenney et al.
patent: 4476912 (1984-10-01), Harvill
patent: 4510987 (1985-04-01), Collot
patent: 4534403 (1985-08-01), Harvill
patent: 4537242 (1985-08-01), Pryor et al.
patent: 4559991 (1985-12-01), Motomura et al.
patent: 4586560 (1986-05-01), Ikeya et al.
patent: 4635706 (1987-01-01), Behrens
patent: 4687042 (1987-08-01), Young
patent: 4694881 (1987-09-01), Busk
patent: 4694882 (1987-09-01), Busk
patent: 4730658 (1988-03-01), Nakano
patent: 4771818 (1988-09-01), Kenney
patent: 4828460 (1989-05-01), Saito et al.
patent: 4834166 (1989-05-01), Nakano
patent: 4884621 (1989-12-01), Ban et al.
patent: 4898714 (1990-02-01), Urban et al.
patent: 4952364 (1990-08-01), Matsuda et al.
patent: 4997027 (1991-0
Foley & Lardner LLP
Takata Corporation
LandOfFree
Injection molding method and apparatus with base mounted feeder does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Injection molding method and apparatus with base mounted feeder, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Injection molding method and apparatus with base mounted feeder will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3270586