U.S. patent application number 12/741127 was filed with the patent office on 2010-09-16 for device and method for low-pressure casting of metal melts.
This patent application is currently assigned to GEORG FISCHER AUTOMOTIVE AG. Invention is credited to Wilhelm Hauke.
Application Number | 20100230066 12/741127 |
Document ID | / |
Family ID | 39032393 |
Filed Date | 2010-09-16 |
United States Patent
Application |
20100230066 |
Kind Code |
A1 |
Hauke; Wilhelm |
September 16, 2010 |
DEVICE AND METHOD FOR LOW-PRESSURE CASTING OF METAL MELTS
Abstract
A device and a method for the low-pressure casting of metal
melts, comprising a casting furnace (1), a feed channel (2) for the
metal melt, a channel (4) in the direction toward the casting mold
(5), and a feed (6) for the gaseous pressure application, an
intermediate container (7) being disposed between the casting mold
(5) and the channel (4), and an access (8) for adding an
inoculating agent (9) being provided in the intermediate container
(7).
Inventors: |
Hauke; Wilhelm;
(Tengen-Blumenfeld, DE) |
Correspondence
Address: |
BACHMAN & LAPOINTE, P.C.
900 CHAPEL STREET, SUITE 1201
NEW HAVEN
CT
06510
US
|
Assignee: |
GEORG FISCHER AUTOMOTIVE AG
Schaffhausen
CH
|
Family ID: |
39032393 |
Appl. No.: |
12/741127 |
Filed: |
November 4, 2008 |
PCT Filed: |
November 4, 2008 |
PCT NO: |
PCT/EP08/64895 |
371 Date: |
May 3, 2010 |
Current U.S.
Class: |
164/55.1 ;
164/284 |
Current CPC
Class: |
B22D 18/04 20130101;
B22D 1/007 20130101 |
Class at
Publication: |
164/55.1 ;
164/284 |
International
Class: |
B22D 18/04 20060101
B22D018/04; B22D 27/00 20060101 B22D027/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 6, 2007 |
EP |
07120039.8 |
Claims
1-6. (canceled)
7. An apparatus for the low pressure casting of metal melts,
comprising: a casting furnace having an inlet feed duct, an outlet
duct and a feed for gaseous pressure application; a casting mold
downstream of the outlet duct; an intermediate vessel located
between the outlet duct and the casting mold; and an access point
to the intermediate vessel for the addition of an inoculant to the
metal melt in the intermediate vessel.
8. The apparatus according to claim 7, further including an
overflow wall arranged in the intermediate vessel.
9. The apparatus according to claim 8, wherein the access point for
the inoculant is arranged upstream of the overflow wall.
10. The apparatus according to claim 7, wherein the intermediate
vessel has an opening and a riser is arranged inside the
intermediate vessel at the opening and the casting mold is
connected directly to the riser above the opening.
11. A process for the low pressure casting of metal melts,
comprising: providing a casting furnace having an inlet feed duct,
an outlet duct and a feed for gaseous pressure application;
providing a casting mold downstream of the outlet duct; providing
an intermediate vessel located between the outlet duct and the
casting mold; providing an access point to the intermediate vessel
for the addition of an inoculant to the metal melt in the
intermediate vessel; and introducing an inoculant into the metal
melt in the intermediate vessel through the access point.
12. The process as claimed in claim 11, including adding the
inoculant in the form of granules.
Description
BACKGROUND OF THE INVENTION
[0001] The invention relates to a device for the low-pressure
casting of metal melts, comprising a casting furnace, a feed duct
for the melt, a duct in the direction toward the casting mold and a
feed for gaseous pressure application.
[0002] During low-pressure casting, the melt is conveyed via a
riser into a casting cavity, counter to the force of gravity, by
subjecting the metallic melt to gaseous pressure application in a
furnace.
[0003] During gravity casting, melts which have additives or
inoculants added to them before the casting for reasons of
nucleation are treated before they enter the mold in the casting
stream, in the tundish and/or in the mold itself.
[0004] According to the prior art, lumps of inoculant can be
introduced, during the low-pressure casting, in the region of the
mold runner in order to dissolve as the mold is filled. The
disadvantage frequently associated with this is, in particular,
that the inoculant in the metal melt is not distributed in a
satisfactory manner in the casting mold. Different concentrations
of the inoculant in the melt can result in considerable deviations
in the desired properties of the cast pieces. This known technique
requires careful adjustment of the composition and of the solution
behavior of the inoculant.
[0005] In order to minimize these disadvantages, it is an object of
the invention to use a device and a process for low-pressure
casting in such a way that the melt is already present with a
uniformly distributed quantity of inoculant in an intermediate
vessel, before the actual filling of the mold.
SUMMARY OF THE INVENTION
[0006] According to the invention, the object is achieved by virtue
of the fact that an intermediate vessel is arranged between the
casting mold and the duct, an access point being provided in the
intermediate vessel for the addition of an inoculant.
[0007] The option of a separate access point for the addition of an
inoculant to an intermediate vessel between the casting furnace and
the casting mold makes it possible to feed a precisely set quantity
of inoculant at the desired point in time in a simple manner.
[0008] According to a preferred embodiment, an overflow wall is
arranged inside the intermediate vessel. It has advantageously been
shown that optimum distribution of the inoculant in the melt, in
particular by the flow, is achieved when the inoculant is
introduced upstream of the intermediate wall.
[0009] Further possible embodiments are described hereinbelow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] An exemplary embodiment is shown in the drawing.
[0011] FIG. 1 shows a sectional view of a furnace.
DETAILED DESCRIPTION
[0012] The casting furnace 1 comprises a feed duct 2 for the
filling operation with metal melt 3. The feed duct 2 can be closed
by means of a cover 14. A feed 6 is provided on the casting furnace
1 in order to apply gas pressure to the melt. Furthermore, a duct 4
adjoined directly by the intermediate vessel 7 is fitted on the
casting furnace 1. The casting mold 5 is arranged above the
intermediate vessel 7 and is connected to the intermediate vessel 7
by way of the riser 13 via the opening 11. A tubular attachment 15
for the addition of the inoculant 9 is fitted at the access point 8
to the intermediate vessel 7. An overflow wall 10 for the melt 3 is
provided inside the intermediate vessel 7 and is arranged slightly
downstream of the end of the duct 4.
[0013] The casting operation proceeds as follows:
[0014] First of all, the casting furnace 1 is filled with metal
melt 3 via the feed duct 2. After the casting furnace 1 has been
filled, the feed duct 2 is closed in a gas-tight manner by means of
a cover 14. The pressures p1, p2 and p3 correspond to atmospheric
pressure. For the transport of iron into the intermediate vessel,
the chamber 16 is subjected to the application of pressure with a
gaseous medium. The pressure p1 is greater than the pressures p2
and p3. The melt begins to flow into the intermediate vessel 7 via
the duct 4 and the overflow wall 10. At the same time, the
inoculant 9 is added via the tubular attachment 15. In FIG. 1, the
addition opening is arranged between the overflow wall 10 and the
casting mold 5. It is likewise conceivable to add the inoculant 9
in the region 17, i.e. upstream of the overflow wall 10. The
inoculant 9 is mixed homogeneously with the metal melt 3 owing to
the flow of the metal melt 3. In order to fill the casting mold 5,
it is necessary to build up the pressure p2, which corresponds to
the height .DELTA.H.
[0015] After the mold has been filled, p2 is lowered to such an
extent that the melt located outside the casting mold can flow back
into the intermediate vessel 7.
* * * * *