U.S. patent application number 14/314091 was filed with the patent office on 2015-01-01 for holder block system and methods for metal casting.
The applicant listed for this patent is Case Western Reserve University. Invention is credited to David SCHWAM.
Application Number | 20150000855 14/314091 |
Document ID | / |
Family ID | 52114454 |
Filed Date | 2015-01-01 |
United States Patent
Application |
20150000855 |
Kind Code |
A1 |
SCHWAM; David |
January 1, 2015 |
HOLDER BLOCK SYSTEM AND METHODS FOR METAL CASTING
Abstract
A holder block system suitable for producing metal castings. The
holder block system includes a holder block primary mold that has
one or more cavities that accept a sub-mold that incorporates the
features of the part to be cast, wherein the sub-mold can be
produced utilizing 3-D printing. Methods of preparing holder block
patterns and cast objects are with the holder block system
disclosed.
Inventors: |
SCHWAM; David; (Beachwood,
OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Case Western Reserve University |
Cleveland |
OH |
US |
|
|
Family ID: |
52114454 |
Appl. No.: |
14/314091 |
Filed: |
June 25, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61841462 |
Jul 1, 2013 |
|
|
|
Current U.S.
Class: |
164/15 ; 164/364;
164/6 |
Current CPC
Class: |
B22C 9/02 20130101 |
Class at
Publication: |
164/15 ; 164/364;
164/6 |
International
Class: |
B22C 9/02 20060101
B22C009/02 |
Claims
1. A holder block system, comprising: a primary mold comprising a
cavity; and a 3-D printed sub-mold located in the cavity, the
sub-mold having an outer surface adapted to mate with at least a
portion of the cavity, and wherein an interior surface of the
sub-mold includes at least one negative image of a component to be
cast.
2. The holder block system according to claim 1, wherein the
sub-mold is formed as a single piece.
3. The holder block system according to claim 1, wherein the
primary mold comprises a gating system, wherein the sub-mold
includes an ingate adapted to align with the gating system on the
primary mold and thereby accept a molten metal into an interior
cavity of the sub-mold.
4. The holder block system according to claim 3, wherein the
sub-mold is free of a separate core and a cope and drag.
5. The holder block system according to claim 1, wherein the
primary mold does not contain any features of a part to be cast
utilizing the holder block system.
6. The holder block system according to claim 1, wherein the
sub-mold is formed from a different material than the primary
mold.
7. The holder block system according to claim 1, wherein the
primary mold comprises a flask and a molding composition located
within the flask, with a cavity being present in the molding
composition.
8. The holder block system according to claim 3, wherein the
primary mold gating system comprises one or more of a sprue, well,
and runner.
9. A method for producing a holder block system, comprising the
steps of: providing a primary mold having at least one cavity and
one or more of a sprue, well, runner and ingate; providing a 3-D
printed sub-mold including an interior surface having a shape of an
object to be molded; inserting the sub-mold into the at least one
cavity of the primary mold to form the holder block system.
10. The method according to claim 9, further including the step of
forming the primary mold by adding a molding composition to a flask
and incorporating a pattern into the molding composition in the
form of the at least one cavity.
11. The method according to claim 10, further including the step of
forming a gating system in the molding composition that includes
one or more of a sprue, well, runner, and end gate.
12. The method according to claim 11, further including the step of
forming an ingate on the sub-mold and aligning the ingate with the
gating system of the primary mold.
13. The method according to claim 12, wherein the primary mold is
formed so that it does not contain any features of a part to be
cast with the holder block pattern.
14. A method for producing a metal casting, comprising the steps
of: obtaining a primary mold having at least one cavity; obtaining
a sub-mold including an interior surface having a shape of an
object to be cast, wherein the sub-mold is 3-D printed and has an
external shape adapted to be placed in at least a portion of the
cavity of the primary mold; inserting the sub-mold into the at
least one cavity of the primary mold; and adding a molten metal to
a portion of the primary mold such that the molten metal flows from
the primary mold into a cavity of the sub-mold including the
interior surface.
15. The holder block system according to claim 14, wherein the
sub-mold is free of a separate core and a cope and drag.
16. The holder block system according to claim 15, wherein the
primary mold comprises a gating system, wherein the sub-mold
includes an ingate aligned with the gating system on the primary
mold and thereby accept the molten metal into an interior cavity of
the sub-mold.
17. The holder block system according to claim 16, wherein the
primary mold does not contain any features of a part to be cast
utilizing the holder block system.
18. The holder block system according to claim 17, wherein the
sub-mold is formed as a single piece; and wherein the primary mold
gating system comprises one or more of a sprue, well, and runner.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a holder block system
suitable for producing metal castings. The holder block system
includes a holder block primary mold that has one or more cavities
that accept a sub-mold that incorporates the features of the part
to be cast, wherein the sub-mold can be produced utilizing 3-D
printing. Methods of preparing holder block patterns and cast
objects with the holder block system are disclosed.
BACKGROUND OF THE INVENTION
[0002] Sand casting is a popular method utilized to produce metal
components having various geometries. Sand molds that are destroyed
in order to remove the cast part are utilized.
[0003] With the advent of 3-D printing, 3-D printers have been
utilized to print molds suitable for use in sand casting. However,
producing cast materials with 3-D printed molds can be quite
expensive, at least in part because of the potentially large amount
of printing material and long time needed to produce a mold and in
some cases a large print size required. 3-D print materials are
also relatively expensive.
SUMMARY OF THE INVENTION
[0004] In view of the above, a problem of the invention is to
provide rapidly producible, yet cost effective metal cast
components.
[0005] The problem of the invention is solved by the holder block
system of the present invention which includes a holder block
primary mold, preferably formed by traditional, inexpensive sand
molding methods, that includes one or more cavities that accept a
sub-mold that includes the features of the component or part to be
cast, wherein the sub-mold is produced utilizing 3-D printing.
[0006] Yet another object of the present invention is to provide a
holder block primary mold that includes one or more cavities, with
a sprue, well, runner and ingate.
[0007] Still another object of the present invention is to provide
a unitary, single piece, 3-D printed sub-mold that is free of a
separate core.
[0008] A further object of the present invention is to provide a
holder block system including a primary mold including a cavity
which contains a sub-mold, wherein the compositions of the mold and
sub-mold are the same or different. In a preferred embodiment, the
materials of the primary mold and sub-mold are different, with the
holder block primary mold fabricated by a traditional no-bake or a
similar sand-molding process. Utilizing a traditional primary
construction, mold preparation time is relatively short and also is
relatively inexpensive. The sub-molds prepared by 3-D printing take
relatively longer time to prepare and also require special
materials.
[0009] Yet another object of the present invention is to provide a
method for providing a holder block system comprising the steps of
providing a primary mold having at least one cavity and one or more
of a sprue, well, runner and ingate; providing a 3-D printed
sub-mold including an interior surface having a shape of an object
to be molded; inserting the sub-mold into the cavity of the mold;
and adding a molten metal to a portion of the mold such that a
molten metal flows into the sub-mold from the mold.
[0010] Still another object of the present invention is to provide
a sub-mold that is formed as a single piece, utilizing 3-D
printing, wherein the sub-mold is free of a cope and drag.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention will be better understood and other features
and advantages will become apparent by reading the detailed
description of the invention, taken together with the drawings,
wherein:
[0012] FIG. 1 illustrates one embodiment of holder block system
which includes a sub-mold ready to be inserted into a holder block
primary mold; and
[0013] FIGS. 2a and 2b illustrate a top view and a bottom view,
respectively, of a cast part made with the holder block primary
mold and the 3-D printed sub-mold shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0014] A holder block system is disclosed comprising a holder block
pattern including a primary mold that has one or more cavities that
accept a sub-mold that incorporates the features of a part to be
cast. The primary mold does not contain any features of the part to
be cast, in a preferred embodiment. Advantageously, the sub-mold is
produced with a 3-D printer. Methods for producing metal castings
with the holder block system of the present invention are
disclosed.
[0015] Primary Mold Production
[0016] The holder block system of the present invention includes a
holder block pattern comprising a holder block primary mold. The
primary mold has one or more cavities that are designed to accept
one or more sub-molds. As illustrated in FIG. 1, the holder block
system 10 includes a primary mold 20 and a sub-mold 40. Primary
mold 20 includes a form such as a flask 22 into which a molding
composition 24 is placed. Any suitable composition known to those
of ordinary skill in the art can be utilized. Molding compositions
typically comprise sand, e.g. silica sand (SiO.sub.2), which is
preferably mixed with a binder or other material that aids in
maintaining the shape of the mold cavity 26 and/or any other
desired features. Sand is relatively inexpensive and resistant to
the temperatures at which metal parts are cast and molded. Various
additives that can be utilized with the sand, include but are not
limited to, various resins, clays, water, and oils.
[0017] The molding composition is added to the flask 22 and placed
around a pattern, which is preferably in the form of a replica of
the external shape of the sub-mold. The pattern can also include a
gating system 28. In other embodiments the gating system is formed
separately. The gating system includes one or more of a sprue 29,
well 30, runner 32 and ingate 34, for example as shown in FIG. 1.
Various types of molds can be created, for example green sand
molds, no-bake molds, air set molds, dry sand molds, cold box
molds, vacuum molds or the like.
[0018] In view of the use of a sub-mold, the holder block mold is
free of any part-specific features. Thus, the holder block pattern
primary mold 20 includes one or more generic cavity blocks or
cavities. The generic cavity or cavities 26 created in the holder
block mold 20 accepts a smaller sub-mold or several small
sub-molds, each made to fit into the cavity. Thus, the holder block
mold provides all the features necessary for casting a
high-integrity part and at the same time, allows the sub-molds to
incorporate only the features of the part to be cast.
[0019] Sub-molds
[0020] As indicated herein, the sub-mold is produced by 3-D
printing. The outer dimensions of the sub-mold 40 are adapted to be
placed in at least a portion of the cavity 26 of mold 20, for
example as illustrated in FIG. 1. The sub-mold 40 includes an
ingate 42 adapted to align with gating system 28 of mold 20 and
thereby accept the molten metal into the interior cavity of
sub-mold 40.
[0021] Various techniques and procedures have been developed which
utilize 3-dimensional printers to form components such as molds,
models and prototypes using 3-D design data. 3-D printers are
available from various sources, including, but not limited to, 3D
Systems, Inc.; EOS GmbH; Prometal, a division of the Ex One
Company; Stratasys, Inc.; and Z Corporation.
[0022] According to the present invention, a 3-D printer is
utilized to print a sand sub-mold directly onto a print bed. As
known to those of ordinary skill in the art, 3-D printing provides
a process for making a 3-dimensional object of virtually any shape
from a digital model. 3-D printing utilizes an additive process
where successive layers of material are laid down in different
shapes. According to the present invention the sub-mold 40 includes
a printed exterior surface 44. The interior surface of the sub-mold
includes at least a negative image of a component to be cast. The
3-D printing process excels in creating complex molds and
eliminates entirely the need for cores. Thus, in one embodiment,
the holder block system of the present invention is free of a
core.
[0023] After the sub-mold 40 is formed, it is placed within the
mold cavity 26 such that the holder block pattern can be
subsequently cast.
[0024] Pouring
[0025] After the holder block system 10 has been assembled, a
desired alloy composition is poured into the mold. Various molten
materials, preferably metal as known to those of ordinary skill in
the art can be utilized. Generally, molten metal is ladled or
poured from a holding container into the sub-mold through the
gating system of the base primary mold 20. A suitable amount of
molten metal is poured in order to fill the entire cavity of the
sub-mold 40 and preferably the gating system 28.
[0026] Finishing
[0027] After the desired component has been cast in the holder
block pattern 10 of the present invention, conventional steps can
be taken to produce a finished component. For example, the mold is
opened after a suitable cooling time has elapsed. In order to
remove the cast component from the holder block pattern, the
sand-based molds are generally broken and the casting removed
therefrom. Excess material can be trimmed from the casting through
any suitable process such as cutting, sawing, trimming or the
like.
[0028] FIG. 2 illustrates a top view and a bottom view,
respectively of the cast component formed utilizing the holder
block mold 20 and sub-mold 40 illustrated in FIG. 1. It is noted
that the "FEF" logo plaque is the usable casting that was inside
the 3-D printed sub-mold. The casting also includes the sprue,
fanned ingate and riser, all necessary to obtain a desirable
plaque.
[0029] While in accordance with the patent statutes the best mode
and preferred embodiment have been set forth, the scope of the
invention is not limited thereto, but rather by the scope of the
attached claims.
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