U.S. patent application number 10/555683 was filed with the patent office on 2007-01-04 for slide shutoff for metal flow in a casting process.
Invention is credited to Robert J. Bend.
Application Number | 20070000635 10/555683 |
Document ID | / |
Family ID | 37588120 |
Filed Date | 2007-01-04 |
United States Patent
Application |
20070000635 |
Kind Code |
A1 |
Bend; Robert J. |
January 4, 2007 |
Slide shutoff for metal flow in a casting process
Abstract
A composite shut-off means for casting moulds, including a
sliding closure made of sand and a compressive refractory material.
The sliding closure has a passageway passing through it so as to
allow the selective passage of molten metal there through, and a
filtering means for the molten metal that filters the metal as it
passes through the passageway. The means for retaining the sliding
closure, are attached to the mould, so that in use, the mould can
be closed and sealed by the sliding closure, and removed from the
launder.
Inventors: |
Bend; Robert J.; (Plymouth,
MI) |
Correspondence
Address: |
Cynthia S Murphy;Renner Otto Boisselle & Sklar
1621 Euclid Avenue
19th Floor
Cleveland
OH
44115
US
|
Family ID: |
37588120 |
Appl. No.: |
10/555683 |
Filed: |
May 7, 2004 |
PCT Filed: |
May 7, 2004 |
PCT NO: |
PCT/AU04/00588 |
371 Date: |
November 4, 2005 |
Current U.S.
Class: |
164/136 ;
164/337 |
Current CPC
Class: |
B22C 9/086 20130101;
B22D 41/22 20130101; B22D 35/04 20130101 |
Class at
Publication: |
164/136 ;
164/337 |
International
Class: |
B22D 35/04 20070101
B22D035/04; B22D 37/00 20060101 B22D037/00 |
Claims
1. A composite shut-off means for casting moulds, including a
sliding closure with at least one passageway passing through it,
wherein in use, when in a first open position the passageway is
positioned so as to allow the passage of molten metal there
through, into the mould, and in a second closed position, the
molten metal is unable to pass through the passageway and the
sliding closure seals the mould, preventing the entry of molten
metal into the mould.
2. A composite shut-off means for casting moulds, including a
sliding closure that includes sealing means, and molten metal
filtering means, wherein said shut-off means is the interface
between the metal source and the mould.
3. The composite shut-off means for casting moulds of claim 1,
further characterised in that the sliding closure is operable by
way of sliding it substantially transverse to metal flow.
4. The composite shut-off means for casting moulds of claim 1,
further characterised in that the sliding closure, and the means
for retaining said sliding closure, are attached to the mould, so
that in use, the mould can be closed and sealed by the sliding
closure, and removed from the launder.
5. The composite shut-off means for casting moulds of claim 1,
further characterised in that the sliding closure is a rectangular
plate element having an aperture or passageway passing there
through.
6. The composite shut-off means for casting moulds of claim 1,
further characterised in that the sliding closure is a composite
construction of sand, binding agent and compressive refractory
material.
7. The composite shut-off means for casting moulds of claim 1,
further characterised in that the sliding closure sealing means
includes a gasket made of compressive refractory material.
8. The composite shut-off means for casting moulds of claim 1,
further characterised in that the sliding closure utilises the
compressive properties of the composite refractory material, such
that in use, the pressure from the launder compresses the sliding
closure, thereby effecting a seal.
9. The composite shut-off means for casting moulds of claim 1,
further characterised in that the filtering means uses either a
stainless steel or fibreglass screen covering the aperture or
passageway in the sliding closure.
10. The composite shut-off means for casting moulds of claim 1,
further characterised in that the sliding closure is actuated by a
pneumatic or hydraulic cylinder.
11. A method of actuating a composite shut-off means for casting
moulds that includes a sliding closure, wherein there is a
production system utilising a carousel that retains the mould, in
which the motion of the carousel indexing is used rotate the
carousel and the mould relative to the sliding closure, which is
held in a fixed position via interference with the launder.
12. A method of actuating a composite shut-off means for casting
moulds that includes a sliding closure, wherein the launder is
attached to a positionable, and programmable three-axis gantry, and
the launder actuates the sliding closure via an interference with
the sliding closure.
13. A method of actuating a composite shut-off means for casting
moulds that includes a sliding closure, wherein a robot retains,
and moves the mould relative to the sliding closure, which is held
in a fixed position via interference with the launder.
14. (canceled)
15. (canceled)
16. The composite shut-off means for casting moulds of claim 2,
further characterised in that the sliding closure is operable by
way of sliding it substantially transverse to metal flow.
17. The composite shut-off means for casting moulds of claim 2,
further characterised in that the sliding closure, and the means
for retaining said sliding closure, are attached to the mould, so
that in use, the mould can be closed and sealed by the sliding
closure, and removed from the launder.
18. The composite shut-off means for casting moulds of claim 2,
further characterised in that the sliding closure is a rectangular
plate element having an aperture or passageway passing there
through.
19. The composite shut-off means for casting moulds of claim 2,
further characterised in that the sliding closure is a composite
construction of sand, binding agent and compressive refractory
material.
20. The composite shut-off means for casting moulds of claim 2,
further characterised in that the sliding closure sealing means
includes a gasket made of compressive refractory material.
21. The composite shut-off means for casting moulds of claim 2,
further characterised in that the sliding closure utilises the
compressive properties of the composite refractory material, such
that in use, the pressure from the launder compresses the sliding
closure, thereby effecting a seal.
22. The composite shut-off means for casting moulds of claim 2,
further characterised in that the filtering means uses either a
stainless steel or fibreglass screen covering the aperture or
passageway in the sliding closure.
23. The composite shut-off means for casting moulds of claim 2,
further characterised in that the sliding closure is actuated by a
pneumatic or hydraulic cylinder.
Description
TECHNICAL FIELD
[0001] The present invention relates to the sand casting of metals
and more particularly to the use of a composite shut-off that
isolates the mould from the launder, and seals the liquid in the
casting during the sand moulds rotation through 180.degree..
BACKGROUND ART
[0002] For purposes of explanation, reference will be made to the
use of the present invention with respect to the casting of motor
cases (engine blocks). It should be understood by those of ordinary
skill in the art that the invention is not limited to use in
casting engine blocks and can be used in the casting of other
products. Cylinder Blocks have traditionally been manufactured as a
casting in Cast Iron. Recently Aluminium alloys have become the
material of choice for cylinder locks.
[0003] While the weight and thermal conduction rates of aluminium
have big advantages over cast iron, the actual casting of liquid
aluminium is problematic. Conventional gravity pouring of aluminium
alloys results in turbulent flow and the manifestation of oxides
dispersed through the casting. These oxides often become the
failure points for the casting in service. To overcome this problem
with oxide formation, counter gravity filling of the liquid
aluminium from the bottom of the mould has become the preferred
method of casting.
[0004] The major problem with counter gravity filling of moulds is
the slow production rates, the mould filling system either low
pressure or electromagnetic pump need to retain pressure until the
casting has solidified. Which for a cylinder block can be up to
eight minutes. While the counter gravity filling is desirable, the
solidification time and subsequent low productivity are not. To
overcome this low productivity problem, methods of disconnecting
the mould from the filling system and rotating the mould while the
casting is still liquid have been developed. Once the mould and
casting are rotated through 1800 the risers which supply liquid
metal during the solidification phase of the cast process are on
top of the casting and gravity feed the required liquid metal into
the contracting casting.
[0005] A major problem has been the effective isolation and sealing
of the mould, once filled with liquid aluminium, from the launder,
so that the mould can be rotated, thereby leaving the launder free
to accept a new mould ready for filling.
[0006] It is an object of the present invention therefore, to
provide a means for effecting sealing of the mould, such that it
can be disconnected from the metal source and the pump launder,
thereby permitting all post filling actions, including rollover, to
be undertaken while the next mould is moving to the cast position.
This offers the advantage of greatly reducing casting cycle
times.
[0007] A further object of the invention is to provide a means for
effecting isolation and sealing of the mould so as to prevent drain
back of metal from the mould gating into the launder. Known casting
methods rotate the mould whilst it is connected to the metal source
pump and launder. When the rotation is complete the pressure on the
mould is reduced to bias level, which is the top of the launder.
This action allows liquid metal in the gating to flow back into the
pump launder contaminating the metal to be used in subsequent
casting operations.
[0008] Yet a further object of the invention is to provide a means
for effecting isolation and sealing of the mould, wherein when the
slide is in the open position, it is filtering the molten metal
passing there through, thereby removing undesirable inclusions.
DISCLOSURE OF THE INVENTION
[0009] Thus there is provided according to one form of the present
invention, a composite shut-off means for casting moulds, including
a sliding closure with at least one passageway passing through it,
wherein in use, when in a first open position the passageway is
positioned so as to allow the passage of molten metal there
through, into the mould, and in a second dosed position, the molten
metal is unable to pass through the passageway and the sliding
closure seals the mould, preventing the entry of molten metal into
the mould.
[0010] In a further form, the invention may be said to lie in a
composite shut-off means for casting moulds, including a sliding
closure that includes sealing means, and molten metal filtering
means, wherein said shut-off means is the interface between the
metal source and the mould.
[0011] Preferably, the sliding closure is operable by way of
sliding it substantially transverse to metal flow.
[0012] Preferably, the sliding closure, and the means for retaining
said sliding closure, are attached to the mould, so that in use,
the mould can be closed and sealed by the sliding closure, and
removed from the launder.
[0013] Preferably, the sliding closure is a rectangular plate
element having an aperture or passageway passing there through.
[0014] Preferably, the sliding closure is a composite construction
of sand, binding agent and compressive refractory material.
[0015] Preferably, the sliding closure sealing means includes a
gasket made of compressive refractory material.
[0016] Preferably, the sliding closure utilises the compressive
properties of the composite refractory material, such that in use,
the pressure from the launder compresses the sliding closure,
thereby effecting a seal.
[0017] Preferably, the filtering means uses either a stainless
steel or fibreglass screen covering the aperture or passageway in
the sliding closure.
[0018] Preferably, the sliding closure is actuated by a pneumatic
or hydraulic cylinder.
[0019] In a further form, the invention may be said to lie in a
method of actuating a composite shut-off means for casting moulds
that includes a sliding closure, wherein there is a production
system utilising a carousel that retains the mould, in which the
motion of the carousel indexing is used rotate the carousel and the
mould relative to the sliding closure, which is held in a fixed
position via interference with the launder.
[0020] In a further form, the invention may be said to lie in a
method of actuating a composite shut-off means for casting moulds
that includes a sliding closure, wherein the launder is attached to
a positionable, and programmable three-axis gantry, and the launder
actuates the sliding closure via an interference with the sliding
closure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] For a better understanding of this invention it will now be
described with respect to preferred embodiments which shall be
described with the assistance of drawings wherein;
[0022] FIG. 1 is a detail top elevation of the shut-off slide,
[0023] FIG. 2 is an end elevation of the shut-off slide shown in
FIG. 1,
[0024] FIG. 3 is a cross-sectional view through a casting mould
illustrating the operation of the shut-off slide, wherein the slide
is in the open position,
[0025] FIG. 4 is a cross-sectional view through the casting mould
illustrating the operation of the shut-off slide, wherein the slide
is in the closed position, and
[0026] FIG. 5 is a cross-sectional view through the casting mould
illustrating the mould post separation from the launder, and
subsequent inversion.
BEST MODE FOR CARRYING OUT THE INVENTION
[0027] There is a sliding closure, or shut-off gate 1 having a
passageway or aperture 2 passing there through. The slide is a
composite construction of sand 3, binding agent and compressive
refractory material 4, and the aperture 2 has a filter screen 5
covering it. This filter screen 5 may be either a stainless steel
or fibreglass screen, and its purpose is to remove any undesirable
inclusions from the molten metal before they can get into the mould
6, and therefore the cast product. A significant advantage of these
composite slides is they can be reclaimed in the same manner as the
remainder of the mould 6, post casting.
[0028] There is a casting launder 7 which can provide molten metal
8 to the mould via the passageway 2 in the sliding closure 1 when
the gate is in the open position 9.
[0029] When the sliding closure 1 is in a first open position 9,
the passageway 2 is positioned so as to allow the passage of molten
metal 8 there through, into the mould 6. When the sliding closure 1
is in a second closed position 10, the molten metal is unable to
pass through the passageway and the sliding closure seals the
mould, preventing the entry of molten metal into the mould, thereby
isolating the mould 6 from the launder 7. The full mould 6 can then
be separated from the launder and rotated while a fresh mould 15 is
filling.
[0030] When in a closed position 10 on the launder, the sliding
closure utilises the pressure from the launder to compress the
composite refractory material 4 in the sliding closure, thereby
effecting the seal discussed in the paragraph above.
[0031] The sliding closure 1 can be actuated by either a pneumatic
or hydraulic cylinder. Alternatively, it can be opened and closed
utilising a carousel that retains the mould 6, in which the motion
of the carousel indexing is used rotate the carousel and the mould
relative to the sliding closure, which is held in a fixed position
via interference with the launder 7.
[0032] Another method of actuating the sliding closure, involves
attaching the launder 7 to a positionable, and programmable
three-axis gantry (not shown); the launder 7 then actuates the
sliding closure via an interference with the sliding closure 1.
[0033] A further method still of activating the sand slide might
make use of a robot that manipulates the sand mould prior, during
and after the casting cycle. This robot then would replace the
carousal discussed above, in that it is the robot that moves the
mould relative to the sliding closure, which is held in place due
to the interference with the launder.
[0034] Articles such as those described herein would prove to be of
considerable benefit in sand casting applications where cycle time
for the casting operation is an important consideration.
[0035] Throughout this specification then the purpose of the
description has been to illustrate the invention and not to limit
this.
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