U.S. patent application number 12/940075 was filed with the patent office on 2012-05-10 for die casting system machine configurations.
Invention is credited to Steven J. Bullied, Gaurav M. Patel, Carl R. Verner.
Application Number | 20120111522 12/940075 |
Document ID | / |
Family ID | 44905686 |
Filed Date | 2012-05-10 |
United States Patent
Application |
20120111522 |
Kind Code |
A1 |
Bullied; Steven J. ; et
al. |
May 10, 2012 |
DIE CASTING SYSTEM MACHINE CONFIGURATIONS
Abstract
A die casting system includes a die, a shot tube and a shot tube
plunger. The die casting system is positioned relative to a
surface. The die includes a plurality of die components that define
a die cavity. The shot tube is in fluid communication with the die
cavity. The shot tube plunger is moveable within the shot tube to
communicate molten metal into the die cavity. Each of the die, the
shot tube and the shot tube plunger are inclined at an angle
relative to the surface during injection of the molten metal into
the die cavity.
Inventors: |
Bullied; Steven J.; (Pomfret
Center, CT) ; Verner; Carl R.; (Windsor, CT) ;
Patel; Gaurav M.; (Glastonbury, CT) |
Family ID: |
44905686 |
Appl. No.: |
12/940075 |
Filed: |
November 5, 2010 |
Current U.S.
Class: |
164/113 ;
164/312 |
Current CPC
Class: |
B22D 17/04 20130101;
B22D 17/14 20130101; B22D 17/30 20130101; B22D 17/2038 20130101;
B22D 17/2023 20130101; B22D 17/10 20130101 |
Class at
Publication: |
164/113 ;
164/312 |
International
Class: |
B22D 27/11 20060101
B22D027/11; B22D 17/04 20060101 B22D017/04 |
Claims
1. (canceled)
2. (canceled)
3. (canceled)
4. (canceled)
5. (canceled)
6. A die casting system, comprising: a die comprised of a plurality
of die components that define a die cavity; a shot tube in fluid
communication with said die cavity, wherein said shot tube includes
an integrated melting unit configured to heat a charge of material
from a position inside of said shot tube; a shot tube plunger
moveable within said shot tube to communicate said charge of
material into said die cavity; and wherein each of said die, said
shot tube, said integrated melting unit and said shot tube plunger
are positioned within a vacuum chamber.
7. The system as recited in claim 6, wherein said shot tube
includes a first sleeve and a second sleeve, and said integrated
melting unit includes an induction coil.
8. The system as recited in claim 7, wherein said first sleeve is a
graphite sleeve and said second sleeve is a ceramic sleeve.
9. The system as recited in claim 6, wherein said integrated
melting unit includes an induction skull melting system.
10. The system as recited in claim 6, wherein said shot tube
plunger includes a cooled copper shot tube plunger.
11. The system as recited in claim 6, wherein the die casting
system is a vertical die casting system.
12. A method of die casting a component, comprising the steps of:
(a) loading a charge of material within a shot tube of a die
casting system; (b) heating the charge of material at a position
inside said shot tube; and (c) injecting the charge of material
into a die cavity of the die casting system to cast the
component.
13. The method as recited in claim 12, wherein the charge of
material is a molten metal and said step (a) includes the step of:
pouring the molten metal into the shot tube.
14. The method as recited in claim 13, wherein said step (b)
includes the step of: heating the molten metal to a desired
temperature inside of the shot tube.
15. The method as recited in claim 12, wherein the charge of
material is an ingot of material and said step (a) includes the
step of: positioning the solid ingot of material inside of the shot
tube.
16. The method as recited in claim 15, wherein said step (b)
includes the step of: melting the solid ingot of material into a
molten metal inside of the shot tube.
17. The method as recited in claim 12, wherein said step (b)
includes the step of: heating the charge of material with an
integrated melting unit associated with the shot tube of the die
casting system.
18. A die casting system, comprising: a die that defines a die
cavity; a shot tube in fluid communication with said die cavity,
wherein said shot tube includes an integrated melting unit
configured to heat a charge of material from a position inside of
said shot tube without preheating said charge of material from a
position outside of said shot tube; and a shot tube plunger
moveable within said shot tube to communicate said charge of
material into said die cavity.
19. The system as recited in claim 18, wherein each of said die,
said shot tube, said integrated melting unit and said shot tube
plunger are positioned within a vacuum chamber having a vacuum
source.
20. The system as recited in claim 1, wherein said shot tube
plunger includes a cooled copper plunger having cooling channels
that receive a coolant from a coolant source.
Description
BACKGROUND
[0001] This disclosure relates generally to casting, and more
particularly to die casting system machine configurations.
[0002] Casting is a known technique used to yield substantially
net-shaped components. For example, investment casting is often
used in the gas turbine engine industry to manufacture net-shaped
components, such as blades and vanes having relatively complex
shapes. Investment casting involves pouring molten metal into a
ceramic shell having a cavity in the shape of the component to be
cast. Investment casting can be relatively labor intensive, time
consuming and expensive.
[0003] Another known casting technique is die casting. Die casting
involves injecting molten metal directly into a reusable die to
yield a net-shaped component. Die casting has typically been used
to produce components that do not require high thermal mechanical
performance. For example, die casting is commonly used to produce
components made from relatively low melting temperature materials
that are not exposed to extreme temperatures. Existing machine
configurations for die casting systems have not been effective to
cast components made from high temperature alloys.
SUMMARY
[0004] A die casting system includes a die, a shot tube and a shot
tube plunger. The die is comprised of a plurality of die components
that define a die cavity. The shot tube is in fluid communication
with the die cavity. The shot tube plunger is moveable within the
shot tube to communicate molten metal into the die cavity. The die
casting system is positioned relative to a surface. Each of the
die, the shot tube and the shot tube plunger are positioned at an
angle relative to the surface during injection of the molten metal
into the die cavity.
[0005] In another exemplary embodiment, a die casting system
includes a die, a shot tube and a shot tube plunger. The die is
comprised of a plurality of die components that define a die
cavity. The shot tube is in fluid communication with the die cavity
and includes an integrated melting unit configured to heat a charge
of material from a position inside the shot tube. The shot tube
plunger is moveable within the shot tube to communicate the charge
of material into the die cavity.
[0006] In yet another exemplary embodiment, a method of die casting
a component includes loading a charge of material into a shot tube
of a die casting system, heating the charge of material at a
position inside the shot tube, and injecting the charge of material
into a die cavity of the die casting system to form the
component.
[0007] The various features and advantages of this disclosure will
become apparent to those skilled in the art from the following
detailed description. The drawings that accompany the detailed
description can be briefly described as follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 illustrates an example die casting system.
[0009] FIG. 2 illustrates an example machine configuration of a die
casting system.
[0010] FIG. 2B illustrates a positioning system of the example die
casting system of FIG. 2.
[0011] FIG. 3 illustrates another example machine configuration of
a die casting system.
[0012] FIG. 3B illustrates an example shot tube plunger of the die
casting system of FIG. 3.
[0013] FIG. 4 illustrates yet another example machine configuration
of a die casting system.
[0014] FIG. 5 schematically illustrates an example implementation
of the die casting system machine configurations of FIG. 3 and FIG.
4.
DETAILED DESCRIPTION
[0015] FIG. 1 illustrates a die casting system 10 having a machine
configuration 11. In this example, the die casting system 10
includes a horizontal machine configuration. The die casting system
10 includes a reusable die 12 having a plurality of die elements
14, 16 that function to cast a component 15. Although two die
elements 14, 16 are depicted in FIG. 1, it should be understood
that the die 12 could include more or fewer die elements, as well
as other parts and configurations.
[0016] The die 12 is assembled by positioning the die elements 14,
16 together and holding the die elements 14, 16 at a desired
positioning via a mechanism 18. The mechanism 18 could include a
clamping mechanism of appropriate hydraulic, pneumatic,
electromechanical and/or other configurations. The mechanism 18
also separates the die elements 14, 16 subsequent to casting.
[0017] The die elements 14, 16 define internal surfaces that
cooperate to define a die cavity 20. A shot tube 24 is in fluid
communication with the die cavity 20 via one or more ports 26
located in the die element 14, the die element 16, or both. A shot
tube plunger 28 is received within the shot tube 24 and is moveable
between a retracted and injected position (in the direction of
Arrow A) within the shot tube 24 by a mechanism 30. The mechanism
30 could include a hydraulic assembly or other suitable mechanism,
including, but not limited to, pneumatic, electromechanical or any
combination thereof.
[0018] The shot tube 24 receives a molten metal from a melting unit
25, such as a crucible, for forming the component 15. In this
example, the molten metal is melted in the melting unit 25 at a
location that is separate from the shot tube 24. However, this
disclosure is not limited to melting units located separate from
the other die casting system components.
[0019] Materials capable of being used to diecast a component 15
include, but are not limited to, nickel based super alloys,
titanium alloys, high temperature aluminum alloys, copper based
alloys, iron alloys, molybdenum, tungsten, niobium or other
refractory metals. This disclosure is not limited to the disclosed
alloys, and it should be understood that any high melting
temperature material may be utilized to cast the component 15. As
used herein, the term "high melting temperature material" is
intended to include materials having a melting temperature of
approximately 1500.degree. F./815.degree. C. and higher.
[0020] The shot tube 24 receives a sufficient amount of molten
material to fill the die cavity 20. The shot tube plunger 28 is
actuated to inject the molten metal under pressure from the shot
tube 24 into the die cavity 20 to cast the component 15. Although
the casting of a single component is depicted, the die casting
system could be configured to cast multiple components in a single
shot (see FIGS. 3 and 4, for example).
[0021] Although not necessary, at least a portion of the die
casting system 10 can be positioned within a vacuum chamber 34 that
includes a vacuum source 35. A vacuum is applied in the vacuum
chamber 34 via the vacuum source 35 to render a vacuum die casting
process. The vacuum chamber 34 provides a non-reactive environment
for the die casting system 10 that reduces reaction, contamination,
or other conditions that could detrimentally affect the quality of
the cast component 15, such as excess porosity of the die cast
component that can occur as a result of exposure to oxygen. In one
example, the vacuum chamber 34 is maintained at a pressure between
1.times.10.sup.-3 Torr and 1.times.10.sup.-4 Torr, although other
pressures are contemplated. The actual pressure of the vacuum
chamber 34 will vary based on the type of component 15 being cast,
among other conditions and factors. In the illustrated example, the
melting unit 25, the shot tube 24, and the die 12 are positioned
within the vacuum chamber 34 during the die casting process such
that the melting, injecting and solidifying of the metal are each
performed under vacuum. In another example, the vacuum chamber 34
is backfilled with an inert gas, such as Argon, for example.
[0022] The machine configuration 11 of the die casting system 10
depicted in FIG. 1 is illustrative only and could include more or
less sections, parts and/or components. This disclosure extends to
all forms of die casting, including but not limited to, horizontal
systems, vertical systems, vacuum systems, or non-vacuum systems.
Described below are additional machine configurations of die
casting systems capable of casting components made from high
melting temperature materials. The example machine configurations
described below and depicted in FIGS. 2-5 maintain thermal control
of the molten metal received by the die casting system components
and thereby minimize thermal losses (i.e., heat of the molten
metal) during injection. In addition, the example machine
configurations extend part life and reduce the defects caused by
transfer of the molten metal from a location separate from the die
casting system components.
[0023] FIG. 2 illustrates an example machine configuration 111 of a
die casting system 110. In this disclosure, like reference numerals
signify like features, and reference numerals identified in
multiples of 100 signify slightly modified features. Moreover,
selected features of one example embodiment may be combined with
selected features of other example embodiments and still fall
within the scope of this disclosure.
[0024] In this example, the die casting system 110 is positioned
relative to a surface 40, such as a machine shop floor, for
example. The surface 40 is substantially flat. The die casting
system 110 is substantially similar to the die casting system 10 of
FIG. 1, except that the die casting system 110 is positioned at an
angle .alpha. relative to the surface 40. That is, the machine
configuration 111 includes an inclined positioning of the die
casting system 110 relative to the surface 40.
[0025] In this example, the die 12, the shot tube 24 and the shot
tube plunger 28 are each angled relative to the surface 40 at an
angle .alpha.. The machine configuration 111 therefore changes the
orientation of the die casting system 110 relative to the surface
40 such that the surface area contact between molten metal and the
interior of the shot tube 24 is reduced. Reduction of the surface
area contact of the molten metal with the shot tube 24 minimizes
thermal losses of the molten metal that can occur during injection,
and reduces the thermal stresses acting upon the shot tube 24.
[0026] The depicted angle .alpha. is for illustrative purposes only
and is not meant to limit this disclosure. In one example, the die
casting system 110 is angled relative to the surface 40 at an angle
of about 5.degree. to about 85.degree.. In another example, the die
casting system 110 is angled relative to the surface 40 at an angle
of about 30.degree. to about 45.degree. . In this disclosure, the
term "about" is intended to include the defined ranges and any
slight modifications thereof, such as within a range of accepted
tolerances.
[0027] The die casting system 110 could be permanently inclined
relative to the surface 40, such as by mounting the die casting
system 110 to an inclined surface 41. In another example, as
depicted in FIG. 2B, the die casting system 110 includes a
positioning system 42 that selectively inclines the die casting
system 110 relative to the surface 40. In this example, the
positioning system 42 includes cylinders 44 that are selectively
actuable to position the die casting system 110 at a desired angle
.alpha. relative to the surface 40. The positioning system 42 could
include any appropriate hydraulic, pneumatic, electromechanical
and/or other configurations for positioning the components of the
die casting system 110 at a desired inclined angle .alpha..
[0028] Although not depicted, the die casting system 110 could be
positioned within a vacuum chamber powered by a vacuum source to
render a vacuum die casting system, or a die casting system 110
could be positioned within a chamber that is backfilled with an
inert gas, such as Argon, for example.
[0029] FIG. 3 illustrates another example machine configuration 211
for a die casting system 210. In this example, the machine
configuration 211 of the die casting system 210 includes a
vertical, bottom feed configuration. Although a vertical, bottom
feed configuration is depicted, the advantages of this disclosure
are applicable to other configurations including, but not limited
to, horizontal, side feed and top feed configurations.
[0030] The die casting system 210 includes a die 212 having a
plurality of die elements 214, 216 that define a die cavity 220. A
shot tube 224 is in fluid communication with the die cavity 220. A
gate 221 connects the shot tube 224 to the die cavity 220. A shot
tube plunger 228 is received within the shot tube 224 and is
moveable between a retracted and injected position (in the
direction of arrow A) within the shot tube 224 by a mechanism
230.
[0031] The shot tube 224 includes an integrated melting unit 225
configured to heat a charge of material 237 from an interior
position IP of the shot tube 224. In this example, the integrated
melting unit 225 includes an induction coil 227 mounted about the
shot tube 224. The induction coil 227 of the integrated melting
unit 225 induces a current within the shot tube 224 to melt and/or
superheat the charge of material 237 within the interior position
IP of the shot tube 224. That is, the charge of material 237 can be
either melted from inside of the shot tube 224, or can be melted
separate from the shot tube 224 (such as in a crucible) and then
transferred to the shot tube 224 and heated to a desired
temperature inside of the shot tube 224. The induction coil 227 is
powered by a power source 229 in a known manner.
[0032] The example shot tube 224 can include a first sleeve 231 and
a second sleeve 233. In this example, the first sleeve 231 is a
graphite sleeve and the second sleeve 233 is a ceramic sleeve. The
induction coil 227 is positioned around the second sleeve 233 to
melt and/or heat a charge of material 237 (such as an ingot of a
high melting temperature material) within the second sleeve 233.
The charge of material 237 is transformed into molten metal and/or
superheated once induced by the induction coil 227. The shot tube
plunger 228 packs the molten metal into the first sleeve 231 of the
shot tube 224. The first sleeve 231 is capable of withstanding the
pressure of the packed molten metal.
[0033] The sleeves 231, 233 are not limited to graphite and ceramic
materials. For example, the first sleeve 231 could also be
comprised of metallic or ceramic materials, while the second sleeve
233 could include other materials. The actual materials utilized
for the first sleeve 231 and the second sleeve 233 will vary
depending upon design specific parameters, including but not
limited to, the melting temperature of the charge of material 237
and the packing pressures created during injection of the shot tube
plunger 228.
[0034] FIG. 3B depicts example features of the shot tube plunger
228. The shot tube plunger 228 could include a cooled copper
plunger 250. In this example, the cooled copper plunger 250
includes cooling channels 251 that receive a coolant 253, such as
water, from a coolant source 255. The coolant 253 is circulated
through the coolant channels 251 to remove heat from the shot tube
plunger 228 as a result of direct contact with the molten metal
during injection.
[0035] As depicted in FIG. 3, the die casting system 210 could be
positioned within a vacuum chamber 234 that includes a vacuum
source 235. A vacuum is applied in the vacuum chamber 234 via the
vacuum source 235 to render a vacuum die casting process. In the
illustrated example, each of the shot tube 224, the integrated
melting unit 225 and the die 212 are positioned within the vacuum
chamber 234 during the die casting process such that the melting,
injecting and solidifying of the metal are all performed under
vacuum. Although a vacuum chamber 234 is depicted in FIG. 3, the
die casting system 210 may also be utilized in non-vacuumed
environments.
[0036] FIG. 4 illustrates yet another example machine configuration
311 associated with a die casting machine 310. The die casting
system 310 is substantially similar to the die casting system 210
of FIG. 3. However, the example die casting system 310 includes a
slightly modified integrated melting unit 325. In this example, the
integrated melting unit 325 includes an induction skull melting
system 327. That is, in this example machine configuration 311, the
induction skull melting system 327 replaces the induction coil 227
depicted in FIG. 3.
[0037] The die casting system 310 also includes a die 312 having a
plurality of die elements 314, 316 that define a die cavity 320. A
shot tube 324 is in fluid communication with the die cavity 320. A
gate 321 connects the shot tube 324 to the die cavity 320. A shot
tube plunger 328 is received within the shot tube 324 and is
moveable between a retracted and injected position (in the
direction of arrow A) within the shot tube 324 by a mechanism 230.
Although not depicted, the die casting system 310 could be
positioned within a vacuum chamber powered by a vacuum source to
render a vacuum die casting system.
[0038] The induction skull melting system 327 of the integrated
melting unit 325 includes wall segments 91 which are surrounded by
an induction coil 93. In this example, the wall segments 91 are
copper wall segments. The wall segments 91 and the induction coil
93 include cooling chambers 95 that receive a coolant, such as
water, from a coolant source 97 to cool the wall segments 91 during
contact with molten metal. A magnetic field is induced by the
induction coil 93 and passes through the wall segments 91 to heat
and melt the charge of material 337 to form molten metal.
[0039] The shot tube plunger 328 is moveable to pack the molten
metal within a sleeve 331 of the shot tube 324 to prepare the
molten metal to be injected into the die cavity 320. In this
example, the shot tube plunger 328 is a copper shot tube plunger
and could include cooling channels (similar to those depicted by
FIG. 3B) to cool the shot tube plunger 328 during contact with the
molten metal.
[0040] FIG. 5 schematically illustrates an example implementation
100 of the machine configurations 211, 311 of FIG. 3 and FIG. 4.
The example implementation 100 schematically depicts a method of
die casting a component 15. The component 15 could include an
aeronautical component, such as an airfoil or vane, for example.
However, the casting of non-aeronautical components is also
contemplated as within the scope of this disclosure.
[0041] The example implementation 100 includes loading a charge of
material 237, 337 within a shot tube 224, 324 of a die casting
system 210, 310, which is depicted at step block 102. In one
example, the charge of material 237, 337 is molten metal that is
melted in a melting unit 25 (See FIG. 1) separate from the die
casting systems 210, 310 and poured into the shot tube 224, 324. In
another example, the charge of material 237, 337 is a solid ingot
of material that is positioned inside the shot tube 224, 324 prior
to melting. The charge of material 237, 337 is a high melting
temperature material.
[0042] Next, at step block 104, the charge of material 237, 337 is
heated from a position inside of the shot tube 224, 324. The charge
of material 237, 337 is heated with an integrated melting unit 225,
325. A skull 75 forms on an interface defined between the shot tube
plunger 228, 328 and the molten metal to seal the shot tube 224,
324. Once the charge of material 237, 337 is either melted or
achieves a desired temperature, the molten metal is advanced
through the integrated melting unit 225, 325 at step block 106.
During advancement, the shot tube plunger 228, 328 pushes on the
skull 75 formed at step block 104. Formation and advancement of the
skull 75 protects the shot tube 224, 324 from exposure to the
molten metal and protects the molten metal from contamination.
[0043] At step block 108, the shot tube plunger 228, 328 crushes
the skull 75 and the molten metal is rapidly injected into the die
cavity 220, 320 of the die 212, 312. The molten metal solidifies
within the die cavity 220, 320 to form the component 15 at step
block 110. Finally, at step block 112, the die 212, 312 is opened
and the component 15 is removed relative to the die 212, 312. The
component 15 can be subjected to finishing operations once removed
from the die 212, 312.
[0044] The foregoing description shall be interpreted as
illustrative and not in any limiting sense. A worker of ordinary
skill in the art would understand that certain modifications could
come within the scope of this disclosure. For these reasons, the
following claims should be studied to determine the true scope and
content of this disclosure.
* * * * *