U.S. patent application number 12/940084 was filed with the patent office on 2012-05-10 for shot tube plunger for a die casting system.
Invention is credited to Steven J. Bullied, Kevin W. Schlichting, Carl R. Verner, Benjamin Joseph Zimmerman.
Application Number | 20120111524 12/940084 |
Document ID | / |
Family ID | 44905683 |
Filed Date | 2012-05-10 |
United States Patent
Application |
20120111524 |
Kind Code |
A1 |
Schlichting; Kevin W. ; et
al. |
May 10, 2012 |
SHOT TUBE PLUNGER FOR A DIE CASTING SYSTEM
Abstract
A shot tube plunger for a die casting system includes a first
face, an opposing second face and an outer surface disposed between
said first face and said opposing second face. A channel
circumferentially extends about the outer surface. The channel is
operable to receive a portion of a charge of material introduced
into the die casting system.
Inventors: |
Schlichting; Kevin W.;
(South Glastonbury, CT) ; Bullied; Steven J.;
(Pomfret Center, CT) ; Verner; Carl R.; (Windsor,
CT) ; Zimmerman; Benjamin Joseph; (Enfield,
CT) |
Family ID: |
44905683 |
Appl. No.: |
12/940084 |
Filed: |
November 5, 2010 |
Current U.S.
Class: |
164/113 ;
164/312 |
Current CPC
Class: |
B22D 17/203
20130101 |
Class at
Publication: |
164/113 ;
164/312 |
International
Class: |
B22D 17/04 20060101
B22D017/04; B22D 27/11 20060101 B22D027/11 |
Claims
1. A die casting system, comprising: a shot tube plunger having a
first face, an opposing second face, and an outer surface disposed
between said first face and said opposing second face, wherein a
channel circumferentially extends about said outer surface, said
channel operable to receive a portion of a charge of material
introduced into the die casting system; and an engagement member
that extends from said first face to establish a contact area for
the charge of material to bond to.
2. The system as recited in claim 1, wherein said channel includes
a circumferential groove that extends radially inward from said
outer surface.
3. (canceled)
4. The system as recited in claim 1, wherein said engagement member
is a recess.
5. The system as recited in claim 1, wherein said engagement member
is a protrusion.
6. The system as recited in claim 1, comprising a shaft, wherein
said second face includes an attachment member that removably
attaches said shot tube plunger to said shaft.
7. The system as recited in claim 6, wherein said attachment member
includes one of a recess and a protrusion and said shaft includes
the other of said recess and said protrusion.
8. The system as recited in claim 1, wherein said shot tube plunger
includes a disposable piston head and said channel extends
circumferentially about said disposable piston head.
9. A die casting system, comprising: a die including a plurality of
die components that define a die cavity; a shot tube in fluid
communication with said die cavity; a shot tube plunger moveable
within said shot tube to communicate a charge of material into said
die cavity; and a disposable piston head removably attached to said
shot tube plunger, wherein said disposable piston head includes a
first face and an opposing second face, and said first face
includes an engagement member that contacts a portion of said
charge of material and said opposing second face includes an
attachment member that removably attaches said disposable piston
head to said shot tube plunger.
10. The system as recited in claim 9, wherein said disposable
piston head includes an outer surface having a channel that
circumferentially extends about said outer surface.
11. The system as recited in claim 9, wherein said engagement
member includes one of a recess and a protrusion.
12. The system as recited in claim 9, wherein said attachment
member includes one of a recess and a protrusion and said shot tube
plunger includes the other of said recess and said protrusion to
removably attach said disposable piston head to said shot tube
plunger.
13. A method of die casting a component with a die casting system,
comprising the steps of: (a) removably attaching a disposable
piston head to a shot tube plunger of the die casting system; (b)
injecting a charge of material through a shot tube and into a die
cavity of the die casting system with the shot tube plunger and
attached disposable piston head; and (c) capturing a portion of the
charge of material in a channel that circumferentially extends
about an outer surface of the disposable piston head such that the
portion of the charge of material captured within the channel
avoids contact with the shot tube during the step of injecting the
charge of material.
14. The method as recited 13, comprising the steps of: (d)
solidifying the charge of material to form the component; and (e)
removing the component from the die cavity with the disposable
piston head still attached to the component.
15. The method as recited 14, comprising the step of: (f) removing
the disposable piston head from the component; and (g) disposing of
the disposable piston head.
16. The method as recited in claim 13, wherein the disposable
piston head includes a first face that faces the charge of
material, the first face including a recess, and wherein said step
(c) includes: capturing a portion of the charge of material within
the recess.
17. The system as recited in claim 9, wherein at least a portion of
said die and said shot tube are disposed within a vacuum
chamber.
18. The system as recited in claim 9, wherein a portion of said
charge of material is received within a circumferential channel of
said disposable piston head, wherein said portion of said charge of
material within said circumferential channel avoids contact with
said shot tube.
19. The system as recited in claim 1, wherein said engagement
feature includes at least one recess that extends from said first
face in direction toward said opposing second face.
20. The system as recited in claim 19, wherein said at least one
recess includes one of a truncated triangular configuration and a
T-shaped configuration.
21. A die casting system, comprising: a shot tube plunger having a
first face, an opposing second face, and an outer surface disposed
between said first face and said opposing second face; an
engagement member that extends from said first face to establish a
contact area for a charge of material to bond to; an attachment
member disposed on said opposing second face, wherein said
attachment member is isolated from contact with said charge of
material; and a channel that circumferentially extends about said
outer surface, wherein said channel receives a portion of said
charge of material such that said portion is entirely spaced from
said outer surface of said shot tube plunger.
Description
BACKGROUND
[0001] This disclosure relates generally to a die casting system,
and more particularly to a shot tube plunger for a die casting
system.
[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. Die casting has not
traditionally been a cost effective method for manufacturing parts
made from high temperature alloys.
SUMMARY
[0004] A shot tube plunger for a die casting system includes a
first face, an opposing second face and an outer surface disposed
between said first face and said opposing second face. A channel
circumferentially extends about the outer surface. The channel is
operable to receive a portion of a charge of material introduced
into the die casting system.
[0005] In another exemplary embodiment, the die casting system
includes a die, a shot tube, a shot tube plunger and a disposable
piston head. 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 a charge of material into the die cavity. The
disposable piston head is removably attached to the shot tube
plunger. The disposable piston head includes a first face and an
opposing second face. The first face includes an engagement member
that contacts a portion of the charge of material and the opposing
second face includes an attachment member that removably attaches
the disposable piston head to the shot tube plunger.
[0006] In yet another exemplary embodiment, a method of die casting
a component with a die casting system includes removably attaching
a disposable head to a shot tube plunger of the die casting system,
injecting a charge of material into a die cavity of the die casting
system with the shot tube plunger and attached disposable piston
head, and capturing a portion of the charge of material in a
channel that circumferentially extends about an outer surface of
the disposable piston head during the step of injecting the charge
of material.
[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] FIGS. 2A-2C illustrates an example shot tube plunger for use
with a die casting system.
[0010] FIG. 3 illustrates another example shot tube plunger for use
with a die casting system.
[0011] FIG. 4A-4F illustrates a first feature of the shot tube
plunger of FIG. 3.
[0012] FIG. 5A-5C illustrates another feature of the shot tube
plunger of FIG. 3.
[0013] FIG. 6A-6E illustrates another feature of the shot tube
plunger of FIG. 3.
[0014] FIG. 7 illustrates a disposable piston head of a shot tube
plunger.
DETAILED DESCRIPTION
[0015] FIG. 1 illustrates a die casting system 10 including a
reusable die 12 having a plurality of die elements 14, 16 that
function to cast a component 15. The component could include
aeronautical components, such as gas turbine engine blades or
vanes, or non-aeronautical components. 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 include 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 that
extend into 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. A shaft 31
extends between the mechanism 30 and the shot tube plunger 28. The
mechanism 30 could include a hydraulic assembly or other suitable
mechanism, including, but not limited to, hydraulic, pneumatic,
electromechanical or any combination of mechanisms.
[0018] The shot tube 24 is positioned to receive a charge of
material, such as molten metal, from a melting unit 32, such as a
crucible, for example. The melting unit 32 may utilize any known
technique for melting an ingot of metallic material to prepare
molten metal for delivery to the shot tube 24, including but not
limited to, vacuum induction melting, electronic beam melting and
induction skull melting. In this example, the molten metal is
melted by the melting unit 32 at a location that is separate from
the shot tube 24 and the die 12. However, other melting
configurations are contemplated as within the scope of this
disclosure. The melting unit 32 of this example is positioned in
relative close proximity to the shot tube 24 to reduce the transfer
distance of the molten metal between the melting unit 32 and the
shot tube 24.
[0019] Materials capable of being used to die cast a component 15
include, but are not limited to, nickel-based super alloys,
cobalt-based super alloys, titanium alloys, aluminum alloys, zinc
alloys, copper-based alloys, iron alloys, molybdenum, tungsten,
niobium or other refractory metals. This disclosure is not limited
to the disclosed alloys, and other high melting temperature
materials may be utilized to die 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 molten metal is transferred from the melting unit 32 to
the shot tube 24 in a known manner. For example, the molten metal
may be poured into a pour hole 33 of the shot tube 24. A sufficient
amount of molten metal is poured into the shot tube 24 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 10 could be
configured to cast multiple components in a single shot.
[0021] Although not necessary, at least a part 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 die cast component, 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 upon the type of component 15 being
cast, among other conditions and factors. In the illustrated
example, each of the melting unit 32, 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 high melting temperature material are all performed under
vacuum. In another example, the chamber 34 is backfilled with an
inert gas, such as Argon, for example.
[0022] The example die casting system 10 depicted in FIG. 1 is
illustrative only and could include more or fewer sections, parts
and/or components. This disclosure extends to all forms of die
casting, including but not limited to, horizontal, inclined or
vertical die casting systems and other die casting
configurations.
[0023] FIGS. 2A-2C illustrate an example shot tube plunger 128 for
use with a die casting system, such as the die casting system 10.
In this disclosure, like reference numerals signify like features,
and reference numerals signified by adding 100 to the original
reference number are slightly modified features. Moreover, selected
features of one example embodiment may be combined with selected
features of other example embodiments within the scope of this
disclosure.
[0024] The shot tube plunger 128 is disposable. That is, the shot
tube plunger 128 is removable from the shaft 31 and may be disposed
of after injection of a charge of material, such as a charge of a
high melting temperature material, to cast a component 15. The
sacrificial shot tube plunger 128 can be removed either after a
single injection or after multiple injections and replaced with
another disposable shot tube plunger 128 for a subsequent
injection. In this example, the shot tube plunger 128 is a
single-piece device having no mechanical attachments. The shot tube
plunger 128 is made from a material capable of withstanding contact
with high melting temperature materials, such as the contact that
occurs during the injection of a charge of material M during the
die casting process, including but not limited to, steel, ceramic,
or other refractory materials.
[0025] The shot tube plunger 128 includes a first face 41, a second
face 43, and an outer cylindrical surface 45 disposed between the
first face 41 and the second face 43. The first face 41 faces the
charge of material M within the shot tube 24, while the second face
43 faces the shaft 31. The shot tube plunger 128 may include an
engagement member 47, an attachment member 49 and/or a channel 51.
Although FIG. 2A illustrates the shot tube plunger 128 having each
of the engagement member 47, the attachment member 49 and the
channel 51, it should be understood that the shot tube plunger 128
could include only one of these features or any combination of such
features. It should also be understood that the outer surface 45 of
the shot tube plunger 128 could be configured to include
non-cylindrical shapes.
[0026] The first face 41 can include the engagement member 47. The
engagement member 47 provides an additional contact area for the
charge of material M to bond to during injection. Once the
injection is complete and the charge of material M is solidified
within the die cavity 20, the disposable shot tube plunger 128
remains attached to the cast component 15 (See FIG. 2B) via cast
portion 17 that bonds to the engagement member 47, but is detached
from the shaft 31. The shot tube plunger 128 is then removed from
the component 15 by removing the cast portion 17 and can then be
disposed of.
[0027] In one example, the engagement member 47 includes a recess
55 (see FIG. 2A). The recess 55 extends from the first face 41,
which faces the charge of material M, toward the second face 43.
The recess 55 can include a variety of shapes and configurations,
including but not limited to, a T-shaped configuration, a
triangular configuration, a truncated configuration, etc. Other
shapes are also contemplated as within the scope of this
disclosure. The first face 41 can include a single recess 55 or
multiple recesses 55. In another example, the engagement member 47
includes a protrusion 57 that protrudes from the first face 41 in a
direction away from the second face 43 (See FIG. 2C). The shot tube
plunger 128 could include a single protrusion 57 (FIG. 2C) or
multiple protrusions 52 (FIG. 4E).
[0028] The shot tube plunger 128 can also include an attachment
member 49 for aligning and affixing the shot tube plunger 128
relative to the shaft 31. The attachment member 49 is disposed on
the second face 43 of the shot tube plunger 128. In one example,
the attachment member 49 includes a recess 59 (see FIG. 2A). The
recess 59 can include multiple shapes and sizes. The recess 59
receives a corresponding protrusion 61 of the shaft 31. In another
example, the attachment member 49 includes a protrusion 63 that
extends from the second face 43 and is received within a
corresponding recess 65 of the shaft 31 (See FIG. 2C).
[0029] The shot tube plunger may also include the channel 51. The
channel 51 circumferentially extends about the outer cylindrical
surface 45. In this example, the channel 51 includes a
circumferential groove 53 that extends radially inwardly from the
outer cylindrical surface 45. The channel 51 could also include
other configurations. For example, the shot tube plunger 128 could
include a single channel 51 or multiple channels 51. As the shot
tube plunger 128 injects the molten metal during the die casting
process, it is possible for a portion P of the molten metal to pass
between an inner wall 25 of the shot tube and the outer cylindrical
surface 45 of the shot tube plunger 128. When this occurs, the
portion P of the charge of material M is captured within the
channel 51 thereby leaving the shot tube 24 free of solidified
metal particles and avoiding gouging of the inner wall 25 that can
occur as the shot tube plunger 128 is retracted.
[0030] FIG. 3 illustrates another example shot tube plunger 228.
The shot tube plunger 228 includes a disposable piston head 40. The
disposable piston head 40 is removably attached to the shot tube
plunger 228 and can be disposed of subsequent to an injection of a
charge of material during a die casting process. The disposable
piston head 40 can be removed from the shaft 31 and disposed of
either after a single injection or after multiple injections. The
disposable piston head 40 is made from a material capable of
withstanding contact with high melting temperature materials. For
example, the disposable piston head 40 could be made from steel,
ceramic, or other refractory materials.
[0031] The disposable piston head 40 defines a first height H1, and
the shot tube plunger 228 defines a second height H2. In this
example, the first height H1 of the disposable piston head 40 and
the second height H2 of the shot tube plunger 228 are generally
equal. Therefore, the shot tube plunger 228 may be reciprocated
between a retracted and injected position without creating
interference with the inner wall 25 of the shot tube 24.
[0032] FIGS. 4A-4F illustrate example features of the disposable
piston head 40. In these examples, the disposable piston head 40
includes a first face 42, a second face 44 and an outer cylindrical
surface 46 disposed between the first face 42 and the second face
44. The first face 42 faces a charge of material M (e.g., molten
metal) within the shot tube 24, while the second face 44 faces the
shot tube plunger 228 (shown in phantom).
[0033] The first face 42 can include an engagement member 48. The
engagement member 48 provides a contact area for the charge of
material M to bond to during injection. Once the injection is
complete and the metal is solidified within the die cavity 20, the
disposable piston head 40 remains attached to the cast component 15
(See FIG. 4F) via a cast portion 17. The disposable piston head 40
can then be removed from the component 15 and disposed of.
[0034] In one example, the engagement member 48 includes a recess
50 (see FIGS. 4A-4C). The recess 50 extends from the first face 42,
which faces the charge of material M, in a direction toward the
second face 44. The recess 50 can include a variety of shapes and
configurations, including truncated triangular configurations
(FIGS. 4A and 4B) and T-shaped configurations (FIG. 4C). Other
shapes are contemplated as within the scope of this disclosure. The
first face 42 can include a single recess 50 (See FIG. 4A) or
multiple recesses 50 (See FIG. 4B).
[0035] FIGS. 4D-4F illustrate another example engagement member 48
of the disposable piston head 40. In this example, the engagement
member 48 includes a protrusion 52 that protrudes from the first
face 42 in a direction away from the second face 44. The disposable
piston head 40 can include a single protrusion 52 (See FIG. 4D), or
multiple protrusions 52 (See FIG. 4E). The protrusions 52 may have
an enlarged head to further secure bonding.
[0036] FIGS. 5A-5C illustrate another feature of the disposable
piston head 40. The disposable piston head 40 includes an
attachment member 54 for aligning and affixing the disposable
piston head 40 to the shot tube plunger 228. The attachment member
54 is disposed on the second face 44 of the disposable piston head
40, which faces in a direction toward the shot tube plunger 228.
That is, the attachment member 54 is positioned on an opposite side
of the disposable piston head 40 from the charge of material M.
[0037] In one example, the attachment member 54 includes a recess
56 (see FIGS. 5A and 5C). The recess 55 can include multiple shapes
and sizes, including but not limited to those depicted in FIG. 5A
and FIG. 5C. The recess 56 receives a corresponding protrusion 60
of the shot tube plunger 228 (shown in phantom) to removably attach
the disposable piston head 40 to the shot tube plunger 228.
[0038] In another example, the attachment member 54 includes a
protrusion 62 that extends from the second face 44 in a direction
toward the shot tube plunger 228. The protrusion 62 is received
within a corresponding recess 64 of the shot tube plunger 228 to
removably attach the disposable piston head 40 to the shot tube
plunger 228.
[0039] FIGS. 6A-6E illustrate yet another feature of the disposable
piston head 40. The disposable piston head 40 can include a channel
58 circumferentially disposed about the outer cylindrical surface
46 of the disposable piston head 40. The channel 58 extends
radially inward from the outer cylindrical surface 46 of the
disposable piston head 40 to define a circumferential groove
66.
[0040] The channel 58 can define any of a multitude of varying
shapes and configurations, such as depicted in FIGS. 6A-6E. In
addition, such as depicted in FIG. 6D, the outer cylindrical
surface 46 of the disposable piston head 40 can include a plurality
of channels 58 defined thereon. As the shot tube plunger 228
injects the charge of material M during the die casting process, it
is possible for a portion P of the charge of material M to pass
between an inner wall 25 of the shot tube 24 and the outer
cylindrical surface 45 of the shot tube plunger 228. When this
occurs, the portion P of the charge of material M is captured
within the channel 58 thereby leaving the shot tube 24 free of
solidified metal particles and avoiding gouging of the inner wall
25 that can occur as the shot tube plunger 228 is retracted (See
FIG. 6A).
[0041] As detailed above, FIGS. 3-6 illustrate multiple features of
the disposable piston head 40. The disposable piston head 40 could
include one or all of the features described herein. For example,
the disposable piston head 40 could include the engagement member
48, the attachment member 54 and the channel 58, or any combination
of these features. FIG. 7, for example, illustrates a disposable
piston head 40 having each of the engagement member 48, the
attachment member 54 and the channel 58.
[0042] It should be understood that many of the features depicted
in FIGS. 1-7 of this disclosure are not illustrated to the scale
they would be in practice. Indeed, many features are shown enlarged
to better illustrate their design and function and should not be
interpreted as limiting this disclosure in any way.
[0043] 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.
* * * * *