WO2002076657A2 - Casting apparatus for the production of metal castings by 'lost-foam' technology - Google Patents

Casting apparatus for the production of metal castings by 'lost-foam' technology Download PDF

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Publication number
WO2002076657A2
WO2002076657A2 PCT/EP2002/003324 EP0203324W WO02076657A2 WO 2002076657 A2 WO2002076657 A2 WO 2002076657A2 EP 0203324 W EP0203324 W EP 0203324W WO 02076657 A2 WO02076657 A2 WO 02076657A2
Authority
WO
WIPO (PCT)
Prior art keywords
container
molten metal
pattern
casting
metal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/EP2002/003324
Other languages
French (fr)
Other versions
WO2002076657A3 (en
Inventor
Andrea Mancusi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Teksid SpA
Teksid Aluminum SRL
Original Assignee
Teksid SpA
Teksid Aluminum SRL
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Teksid SpA, Teksid Aluminum SRL filed Critical Teksid SpA
Priority to EP02726208A priority Critical patent/EP1377399B1/en
Priority to CA002441391A priority patent/CA2441391A1/en
Priority to JP2002575160A priority patent/JP2004535300A/en
Priority to AT02726208T priority patent/ATE271945T1/en
Priority to MXPA03008719A priority patent/MXPA03008719A/en
Priority to US10/472,933 priority patent/US6789582B2/en
Priority to DE60200838T priority patent/DE60200838T2/en
Publication of WO2002076657A2 publication Critical patent/WO2002076657A2/en
Publication of WO2002076657A3 publication Critical patent/WO2002076657A3/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D18/00—Pressure casting; Vacuum casting
    • B22D18/06—Vacuum casting, i.e. making use of vacuum to fill the mould
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/02—Sand moulds or like moulds for shaped castings
    • B22C9/04—Use of lost patterns
    • B22C9/046—Use of patterns which are eliminated by the liquid metal in the mould

Definitions

  • the present invention relates to apparatus for casting molten metal for the production of metal castings by so- called "lost-foam" technology.
  • the invention relates to apparatus of the type comprising:
  • a second container having an upper mouth and containing a bath of granular material, immersed in which is a pattern made of expanded material which can evaporate when contacted by the molten metal, and
  • - filling means for supplying the molten metal from the first container to the pattern in the second container.
  • the primary object of the invention is to provide apparatus which enables the liquid metal to be transferred from the molten-metal container to the pattern without time limitations and without limitations of the amount of metal required to fill the pattern or form.
  • a subject of the invention is apparatus of the type mentioned above which is characterized in that it comprises :
  • the means comprising a removable cover which can seal the mouth of the second container in a leaktight manner and which has a first opening with which vacuum-generating means are associated and a second opening with which the filling means are associated in a leaktight manner so that, when the cover is fitted on the second container in a leaktight manner and the vacuum-generating means are activated, the liquid metal is transferred from the first container to the pattern.
  • a second subject of the invention is a method of casting under reduced pressure, which uses the above-mentioned apparatus .
  • Figure 1 is a schematic view of apparatus according to the invention.
  • Figure 2 is a schematic view of the apparatus in an operative stage following that of Figure 1.
  • a casting container indicated 1 and generally made of metal, has an open upper mouth which, according to the "lost-foam” technique, which is known per se, comprises a bath of foundry sand 2 in which a pattern 3 of the casting to be cast, typically made of expanded polystyrene, is immersed.
  • branches 4 and 5 which are also made of expanded polystyrene and which, during casting, act as ducts for supplying the molten metal to the patterns defining the castings to be produced.
  • the cluster comprises a main branch 4 with a head 6 which projects from the sand bath and in contact with which the molten metal is supplied.
  • the pattern or cluster of patterns and the respective metal- supply ' branch or branches are preferably coated with a coating for rendering the surface of the expanded material permeable to gases.
  • a cover indicated 7, provided with a sealing ring 8, can engage the upper mouth of the container 1 in a leaktight manner in order to isolate the container from the outside atmosphere . ' ,,
  • the cover 7 has a first opening 9 associated with a suction duct 10 communicating with a vacuum pump 11 and with a reduced-pressure valve 12.
  • the cover 7 also comprises a second opening 13 with which filling means 14 are associated in a leaktight manner in order to supply the molten metal from a holding furnace 15 to the casting container 1.
  • the filling means comprise a siphon-like duct 16 that opens in a bell 17 which is preferably covered with ceramic material and is associated with the cover 7 in a leaktight manner.
  • the cover 7 is placed on the mouth of the container 1 so as to seal the mouth of the container in a leaktight manner and the duct 14 is immersed in the bath of molten metal in the holding furnace 15.
  • the bell 17 will sink into the containing sand 2, enclosing the head 6 of the polystyrene cluster.
  • Filling starts with the generation of the partial vacuum by means of the pump 11; during the initial stages of the process, the generation of the partial vacuum - by evacuation of the air contained in the spaces between the granules of foundry sand, - brings about compaction of the sand which improves the quality of the casting. Further vacuum generation then creates the reduced pressure necessary for the metal to flow from the holding furnace 15 into the pattern container 1.
  • the pumping system 11 Upon completion of the filling, the pumping system 11 is deactivated and the reduced-pressure valve 12 is opened in order to re-establish ambient pressure conditions in the container. At this point, the cover 7 is removed from the container, possibly by handling means ' provided specifically for that purpose, to permit withdrawal of the casting or cluster formed.
  • the casting apparatus according to the invention and the respective casting method which uses it enable considerable advantages to be achieved, amongst which, in particular, are:

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacture Of Alloys Or Alloy Compounds (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
  • Polyurethanes Or Polyureas (AREA)
  • Molds, Cores, And Manufacturing Methods Thereof (AREA)

Abstract

Apparatus for casting molten metal for the production of metal castings by 'lost-foam' technology, comprises: a first container (15) of molten metal; a second container (1) having an upper mouth and containing a bath of granular material (2), immersed in which is a pattern (3, 3a) made of expanded material which can evaporate when contacted by the molten metal, and filling means (14) for supplying the molten metal from the first container (15) to the pattern (3, 3a) in the second container (1), and means for applying a partial vacuum to the second container (1), the means comprising a removable cover (7) which can seal the mouth of the second container (1) in a leaktight manner and which has a first opening (9) with which vacuum-generating means (10, 11) are associated and a second opening (13) with which the filling means (14) are associated in a leaktight manner so that, when the cover (7) is fitted on the second container (1) in a leaktight manner and the vacuum-generating means (10, 11) are activated, the liquid metal is transferred form the first container (15) to the pattern (3, 3a).

Description

Casting apparatus for the production of metal castings by "lost-foam" technology
The present invention relates to apparatus for casting molten metal for the production of metal castings by so- called "lost-foam" technology.
In particular, the invention relates to apparatus of the type comprising:
- a first container of molten metal,
- a second container having an upper mouth and containing a bath of granular material, immersed in which is a pattern made of expanded material which can evaporate when contacted by the molten metal, and
- filling means for supplying the molten metal from the first container to the pattern in the second container.
The primary object of the invention is to provide apparatus which enables the liquid metal to be transferred from the molten-metal container to the pattern without time limitations and without limitations of the amount of metal required to fill the pattern or form.
For this purpose, a subject of the invention is apparatus of the type mentioned above which is characterized in that it comprises :
means for applying a partial vacuum to the second container, the means comprising a removable cover which can seal the mouth of the second container in a leaktight manner and which has a first opening with which vacuum-generating means are associated and a second opening with which the filling means are associated in a leaktight manner so that, when the cover is fitted on the second container in a leaktight manner and the vacuum-generating means are activated, the liquid metal is transferred from the first container to the pattern.
A second subject of the invention is a method of casting under reduced pressure, which uses the above-mentioned apparatus .
Further advantages and characteristics of the apparatus and of the method according to the invention will become clear from the following detailed description, given with reference to the appended drawings, in which:
Figure 1 is a schematic view of apparatus according to the invention, and
Figure 2 is a schematic view of the apparatus in an operative stage following that of Figure 1.
In the drawings, a casting container, indicated 1 and generally made of metal, has an open upper mouth which, according to the "lost-foam" technique, which is known per se, comprises a bath of foundry sand 2 in which a pattern 3 of the casting to be cast, typically made of expanded polystyrene, is immersed.
Generally, two or more patterns 3, 3a are connected to one another in a cluster by means of branches 4 and 5 which are also made of expanded polystyrene and which, during casting, act as ducts for supplying the molten metal to the patterns defining the castings to be produced. In the view of Figure 1, the cluster comprises a main branch 4 with a head 6 which projects from the sand bath and in contact with which the molten metal is supplied.
The pattern or cluster of patterns and the respective metal- supply ' branch or branches are preferably coated with a coating for rendering the surface of the expanded material permeable to gases.
A cover, indicated 7, provided with a sealing ring 8, can engage the upper mouth of the container 1 in a leaktight manner in order to isolate the container from the outside atmosphere . ' ,,
The cover 7 has a first opening 9 associated with a suction duct 10 communicating with a vacuum pump 11 and with a reduced-pressure valve 12.
The cover 7 also comprises a second opening 13 with which filling means 14 are associated in a leaktight manner in order to supply the molten metal from a holding furnace 15 to the casting container 1. The filling means comprise a siphon-like duct 16 that opens in a bell 17 which is preferably covered with ceramic material and is associated with the cover 7 in a leaktight manner.
In order to perform the casting step shown in Figure 2, the cover 7 is placed on the mouth of the container 1 so as to seal the mouth of the container in a leaktight manner and the duct 14 is immersed in the bath of molten metal in the holding furnace 15. The bell 17 will sink into the containing sand 2, enclosing the head 6 of the polystyrene cluster. Filling starts with the generation of the partial vacuum by means of the pump 11; during the initial stages of the process, the generation of the partial vacuum - by evacuation of the air contained in the spaces between the granules of foundry sand, - brings about compaction of the sand which improves the quality of the casting. Further vacuum generation then creates the reduced pressure necessary for the metal to flow from the holding furnace 15 into the pattern container 1.
Upon completion of the filling, the pumping system 11 is deactivated and the reduced-pressure valve 12 is opened in order to re-establish ambient pressure conditions in the container. At this point, the cover 7 is removed from the container, possibly by handling means' provided specifically for that purpose, to permit withdrawal of the casting or cluster formed.
The casting apparatus according to the invention and the respective casting method which uses it enable considerable advantages to be achieved, amongst which, in particular, are:
- a large degree of operative flexibility which permits the casting of shaped castings of any size, since it is possible to supply any desired quantity of molten metal held in the withdrawal furnace, without the need for specific metering,
- heat losses in the course of the transfer are low and cycle times are reduced,
- by virtue of the lower thermal losses, it is possible to reduce the supply temperature of the molten metal, thus achieving a reduction in the porosity of the casting, as well as energy saving, and - improved casting quality is also achieved by virtue of the rapid suction of the combustion gases and by virtue of the reduction in the oxidation of the metal alloy resulting from the preliminary removal of the air incorporated in the foundry sand.
Naturally, the principle of the invention remaining the same, the forms of embodiment and details of construction may be varied widely with respect to those described and illustrated by way of non-limiting example, without departing from the scope of the appended claims .

Claims

1. Apparatus for casting molten metal for the production of metal castings by "lost-foam" technology, comprising:
- a first container (15) of molten metal,
a second container (1) having an upper mouth and containing a bath of granular material (2) , immersed in which is a pattern (3, 3a) made of expanded material which can evaporate when contacted by the molten metal, and
- filling means (14) for supplying the molten metal from the first container (15) to the pattern (3, 3a) in the second container (1) ,
characterized in that it comprises:
means for applying a partial vacuum to the second container (1) , the means comprising a removable cover (7) which can seal the mouth o'f the second container (1) in a leaktight manner and which has a first opening (9) with which vacuum-generating means (10, 11) are associated and a second opening (13) with which the filling means (14) are sealingly associated so that, when the cover (7) is fitted on the second container (1) in a leaktight manner and the vacuum-generating means (10, 11) are activated, the liquid metal is transferred from the first container (15) to the pattern (3 , 3a) .
2. Casting apparatus according to Claim 1, characterized in that the filling means (14) comprise a siphon-like duct (16) which opens in a bell (17) sealingly associated with the cover (7) .
3. Casting apparatus according to Claim 2, characterized in that the bell (17) is arranged to surround a head end (6) of a branch (4) of expanded material connected to the pattern (3, 3a) of the casting to be cast.
4. A method of casting molten metal for the production of metal castings by "lost-foam" technology with the use of casting apparatus according to any one of Claims 1 to 3.
PCT/EP2002/003324 2001-03-27 2002-03-25 Casting apparatus for the production of metal castings by 'lost-foam' technology Ceased WO2002076657A2 (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
EP02726208A EP1377399B1 (en) 2001-03-27 2002-03-25 Casting apparatus for the production of metal castings by "lost-foam" technology
CA002441391A CA2441391A1 (en) 2001-03-27 2002-03-25 Casting apparatus for the production of metal castings by "lost-foam" technology
JP2002575160A JP2004535300A (en) 2001-03-27 2002-03-25 Casting equipment used for the production of cast metal by the vanishing model method.
AT02726208T ATE271945T1 (en) 2001-03-27 2002-03-25 CASTING DEVICE FOR PRODUCING METAL CASTINGS USING THE FULL MOLD CASTING METHOD
MXPA03008719A MXPA03008719A (en) 2001-03-27 2002-03-25 Casting apparatus for the production of metal castings by "lost-foam" technology.
US10/472,933 US6789582B2 (en) 2001-03-27 2002-03-25 Casting apparatus for the production of metal castings by “lost-foam” technology
DE60200838T DE60200838T2 (en) 2001-03-27 2002-03-25 CASTING DEVICE FOR MANUFACTURING METAL CAST PIECES IN THE FULL-MOLDING PROCESS

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT2001TO000287A ITTO20010287A1 (en) 2001-03-27 2001-03-27 CASTING EQUIPMENT FOR THE PRODUCTION OF METALLIC CASTINGS USING "LOST-FOAM" TECHNOLOGY.
ITTO2001A000287 2001-03-27

Publications (2)

Publication Number Publication Date
WO2002076657A2 true WO2002076657A2 (en) 2002-10-03
WO2002076657A3 WO2002076657A3 (en) 2002-12-19

Family

ID=11458734

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2002/003324 Ceased WO2002076657A2 (en) 2001-03-27 2002-03-25 Casting apparatus for the production of metal castings by 'lost-foam' technology

Country Status (9)

Country Link
US (1) US6789582B2 (en)
EP (1) EP1377399B1 (en)
JP (1) JP2004535300A (en)
AT (1) ATE271945T1 (en)
CA (1) CA2441391A1 (en)
DE (1) DE60200838T2 (en)
IT (1) ITTO20010287A1 (en)
MX (1) MXPA03008719A (en)
WO (1) WO2002076657A2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101767194B (en) * 2008-12-31 2011-11-09 沈阳理工大学 Quasi pressure adjusting casting machine and casting method thereof

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ITTO20010288A1 (en) * 2001-03-27 2002-09-27 Teksid Spa EQUIPMENT FOR THE TRANSFER OF LIQUID METALS FROM A WITHDRAWAL CONTAINER TO A COLLECTION CONTAINER.
JP4666259B2 (en) * 2006-03-16 2011-04-06 新東工業株式会社 Vanishing model casting method
EP2957365B1 (en) * 2014-06-20 2017-04-12 Imr S.R.L. Method for manufacturing a metallic object by casting

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US58653A (en) * 1866-10-09 Improved carpet-stretcher
SU1310099A1 (en) * 1985-11-13 1987-05-15 Научно-исследовательский институт технологии автомобильной промышленности Casting mould
FR2606688B1 (en) 1986-11-17 1989-09-08 Pechiney Aluminium LOSS FOAM MOLDING PROCESS FOR METAL PARTS
US4787434A (en) * 1986-12-29 1988-11-29 Brunswick Corporation Vacuum lift foam filled casting system
US5062470A (en) * 1988-04-14 1991-11-05 Rikker Leslie D Method and apparatus for treating gaseous material from evaporative pattern casting
FR2647380B1 (en) 1989-05-02 1994-03-11 Chardon Michel METHOD AND DEVICE FOR MOLDING METALS USING GASEOUS MODELS AND BINDERLESS MOLDING MATERIAL
DE19531551A1 (en) * 1995-08-28 1997-03-06 Bruehl Eisenwerk Process for producing castings from light metal and lost mold based on sand therefor
US6499529B1 (en) * 2001-08-17 2002-12-31 Hitchiner Manufacturing Co., Inc. Centrifugal countergravity casting

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101767194B (en) * 2008-12-31 2011-11-09 沈阳理工大学 Quasi pressure adjusting casting machine and casting method thereof

Also Published As

Publication number Publication date
EP1377399A2 (en) 2004-01-07
CA2441391A1 (en) 2002-10-03
US20040149347A1 (en) 2004-08-05
JP2004535300A (en) 2004-11-25
MXPA03008719A (en) 2004-10-15
DE60200838T2 (en) 2005-09-15
ATE271945T1 (en) 2004-08-15
US6789582B2 (en) 2004-09-14
DE60200838D1 (en) 2004-09-02
WO2002076657A3 (en) 2002-12-19
EP1377399B1 (en) 2004-07-28
ITTO20010287A0 (en) 2001-03-27
ITTO20010287A1 (en) 2002-09-27

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