EP0271513A1 - Verfahren und vorrichtung zum verdichten von körnigen formstoffen - Google Patents

Verfahren und vorrichtung zum verdichten von körnigen formstoffen

Info

Publication number
EP0271513A1
EP0271513A1 EP87903237A EP87903237A EP0271513A1 EP 0271513 A1 EP0271513 A1 EP 0271513A1 EP 87903237 A EP87903237 A EP 87903237A EP 87903237 A EP87903237 A EP 87903237A EP 0271513 A1 EP0271513 A1 EP 0271513A1
Authority
EP
European Patent Office
Prior art keywords
pressure surge
molding
molding material
model
pressure
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.)
Withdrawn
Application number
EP87903237A
Other languages
German (de)
English (en)
French (fr)
Inventor
Hans Leutwiler
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.)
Georg Fischer AG
Original Assignee
Georg Fischer AG
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
Priority claimed from CH240486A external-priority patent/CH671715A5/de
Priority claimed from CH299286A external-priority patent/CH671349A5/de
Application filed by Georg Fischer AG filed Critical Georg Fischer AG
Publication of EP0271513A1 publication Critical patent/EP0271513A1/de
Withdrawn legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22CFOUNDRY MOULDING
    • B22C15/00Moulding machines characterised by the compacting mechanism; Accessories therefor

Definitions

  • the present invention relates to a method for compacting granular molding materials, in particular foundry molding materials, by means of pressurization, the molding material being introduced into a molding device with a model plate with a model arranged thereon, a filling and molding frame.
  • a compression process is known from US Pat. No. 3,170,202, which takes place by means of a gas pressure.
  • a gas mixture is ignited to produce an exothermic reaction.
  • the resulting gas pressure then compresses the molding material so that a sand mold is created.
  • DE-PS 1097622 a compression process has become known in which the compression of the molding material is accomplished by expanding a high-pressure gas.
  • Gas pressure molding machines that are used to carry out these compression processes work exclusively on the principle of acceleration compression.
  • a pressure surge is triggered, which acts on the molding material mass at high speed and accelerates it.
  • the compression takes place by braking on the model device.
  • every grain of sand would have to be hit by the pressure wave and the acceleration energy absorbed should be transferred to the next grain layer up to the model set-up. This would result in a uniformly compressed form with high hardness, with the help of which dimensionally accurate castings with high quality properties could be produced.
  • Foundry molding material is poured in loosely in a mold box arrangement.
  • the surface of the molding material is essentially flat and extends into the filling frame.
  • a pressure surge is triggered for the purpose of compressing the filled molding material.
  • a first pressure surge G 1 hits the free molding material surface at time t 1 and begins to push the molding material layer in the direction of the model device layer by layer.
  • a second or a further pressure surge G 2 is brought into effect on a molding material area A at time t 2 .
  • This molding area A is part of the filled molding compound and is arranged at a distance from the free surface of the molding compound in the model direction.
  • the pressure surge G 2 is generally brought into effect before the pressure surge G 1 acts on the molding material surface in the molding material area A. However, it is also possible for this pressure surge G 2 of the pressure surge G 1 already acting to be conducted into the molding material region A.
  • the pressure surges G 1 and G 2 can be derived from one and the same pressure source. However, pressure sources arranged independently of one another can also be used.
  • the pressure surge G1 hits the free surface of the molding material, the upper layer of the molding material mass is compressed, ie compressed. This compression takes place suddenly, with the compressed areas below Move the effect of the pressure towards the model device.
  • the pressure surge G 2 strikes the molding material mass in the molding material area A, ie at a certain distance from the free molding material surface.
  • the flow behavior of the molding material area A is influenced by the pressure surge.
  • the sand grains in this molding material area A are pushed away from the molding box wall, so that the friction between the sand grains and the molding box wall is almost eliminated.
  • the pressure surge G 1 can already reach the surface of the molding material.
  • the molding material mass is set into a compression movement.
  • the effect of this compression movement also sets the molding material area A in motion and moves it in the direction of the model arrangement. This shift lasts until the pressure surge G 1 catches up with the area of influence of the pressure surge G 2 .
  • the duration of the pressure surge G 2 means the time that G 1 and G 2 need to equalize the pressure, ie until the pressure wave G 1 has reached the molding material area A or the area of action of G 2 .
  • the figure shows a section through a molding device.
  • a model 2 is arranged on a model plate 1 and is surrounded by a molding frame 3.
  • a filling frame 4 is seated on the molding frame 3.
  • a pressure chamber, not shown, is indicated with the wall 5.
  • a series of openings 9 is arranged between the mold box wall 3 and the model 2. Before the compacting process, molding sand 6 is filled into the molding combination.
  • a pressure surge D 1 is applied to the molding material surface 8 at time t 1 .
  • a pressure surge D2 is applied in the molding material region A on the molding sand on. Since the molding material is not compressed in area A at time t 2 , this area is fluidized and moves to the same extent in the direction of the model plate as the pressure wave front, triggered by the pressure surge D 1 , moves in the direction of the model plate.
  • the additional air quantity introduced in the molding material area A is discharged via the openings 9 when the model plate 1 is reached. The discharged air can escape from the molding system via a channel 10, which can be connected to the ambient atmosphere.
  • the additional amount of air is led out of the molding material or the molding space during the duration of the pressure surge D 1 , because air quantities enclosed in a molding material are compressed when the molding material is compressed and thus prevent the molding material from being brought to these points, which, as already mentioned, leads to a bad result Shape quality leads.
  • the openings 9 are intended to counteract this and serve to accommodate the amount of air displaced by the molding material. If the pressure prevailing in line 10 is lower than the ambient pressure, a suction effect is created which further supports the removal of the additional air quantity from the molding material mass in the area between molding box wall 3 and model 2.
  • the openings 9 are advantageously arranged along the mold box wall in the model plate. Depending on the distance from the mold box wall 3 and the model 2 or depending on the degree of complexity of the model, the openings can be arranged more densely or their diameters can be varied. In any case, it is important that the openings are arranged in the area of the vertical projection 11 of the effective area of the pressure surge D 2 on the model plate. Tests have shown that this arrangement already has a positive effect when the sum of the cross-sectional areas of the openings 9 is at least 1% of the area between the molding box 3 and the model wall 2a.
  • the proposed method ensures that in the critical molding material areas, namely between the model and the molding box, by reducing the friction between the molding material mass and the molding box wall, the compressibility of the molding material mass in these areas is optimized by the improved flow behavior.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Casting Devices For Molds (AREA)
  • Mold Materials And Core Materials (AREA)
EP87903237A 1986-06-13 1987-06-05 Verfahren und vorrichtung zum verdichten von körnigen formstoffen Withdrawn EP0271513A1 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CH240486A CH671715A5 (en) 1986-06-13 1986-06-13 Compacting casting moulds
CH2404/86 1986-06-13
CH2992/86 1986-07-25
CH299286A CH671349A5 (en) 1986-07-25 1986-07-25 Compacting casting moulds

Publications (1)

Publication Number Publication Date
EP0271513A1 true EP0271513A1 (de) 1988-06-22

Family

ID=25690367

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87903237A Withdrawn EP0271513A1 (de) 1986-06-13 1987-06-05 Verfahren und vorrichtung zum verdichten von körnigen formstoffen

Country Status (11)

Country Link
US (1) US4921035A (cs)
EP (1) EP0271513A1 (cs)
JP (1) JPS63503446A (cs)
CN (1) CN1018897B (cs)
AU (1) AU7438487A (cs)
CA (1) CA1282219C (cs)
CS (1) CS276988B6 (cs)
DK (1) DK72688A (cs)
ES (1) ES2004292A6 (cs)
PL (1) PL154314B1 (cs)
WO (1) WO1987007544A1 (cs)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH672270A5 (cs) * 1986-12-17 1989-11-15 Fischer Ag Georg
DE3701438A1 (de) * 1987-01-20 1988-07-28 Josef Mertes Engineering Fuer Verfahren und vorrichtung zum verdichten von kornfoermigen formstoffen z.b. giessereiformsand
CH682547A5 (de) * 1990-04-20 1993-10-15 Fischer Ag Georg Verfahren und Vorrichtung zum Verdichten von körnigen Formstoffen.
DE4229810C2 (de) * 1991-09-27 1995-02-23 Georg Fischer Giesereianlagen Modellplattenträger für druckluftbeaufschlagte Verdichtungsverfahren
CH686412A5 (de) * 1992-03-10 1996-03-29 Fischer Georg Giessereianlagen Verfahren zum Verdichten von Formsand fuer Giessformen.
JP3083042B2 (ja) * 1994-05-12 2000-09-04 新東工業株式会社 鋳型造型方法
CN102773421B (zh) * 2012-08-20 2015-11-11 机械科学研究总院先进制造技术研究中心 一种数字化无模砂型挤压成形机

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1097622B (de) * 1953-12-31 1961-01-19 Dietrich Pulvermacher Verfahren und Vorrichtung zum gleichmaessigen Verdichten des Formsandes in Pressformmaschinen
US3807483A (en) * 1971-01-08 1974-04-30 E Buhler Methods and apparatus for producing sand molds
JPS55141358A (en) * 1979-04-20 1980-11-05 Sintokogio Ltd Mold molding method
JPS55147461A (en) * 1979-05-08 1980-11-17 Sintokogio Ltd Mold molding method and pattern plate
SU952414A1 (ru) * 1980-04-23 1982-08-23 Всесоюзный научно-исследовательский и проектно-технологический институт угольного машиностроения Способ изготовлени литейных форм "процесс ВМ-3
GB2079654B (en) * 1980-07-09 1984-04-26 Sintokogio Ltd Moulding method and apparatus
DE3202395A1 (de) * 1981-01-28 1982-08-26 BMD Badische Maschinenfabrik Durlach GmbH, 7500 Karlsruhe Verfahren und vorrichtung zum pneumatischen verdichten von formsand
JPS58500474A (ja) * 1981-04-02 1983-03-31 ベ−エムデ−・バ−ディッシェ・マシ−ネンファブリ−ク・ドゥルラッハ・ゲ−エムベ−ハ− 型砂の空気圧圧縮法及び装置
JPS58125339A (ja) * 1982-01-20 1983-07-26 Mitsubishi Heavy Ind Ltd 鋳型造型方法
JPS58125399A (ja) * 1982-01-20 1983-07-26 Sanyo Electric Co Ltd ゴミ圧縮機
DE3511283A1 (de) * 1985-03-28 1986-10-09 Dietmar Prof. Dr.-Ing. 5100 Aachen Boenisch Verfahren und vorrichtung zum verdichten von giessereiformstoffen

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO8707544A1 *

Also Published As

Publication number Publication date
CA1282219C (en) 1991-04-02
DK72688D0 (da) 1988-02-12
CN87104710A (zh) 1988-05-18
CN1018897B (zh) 1992-11-04
AU7438487A (en) 1988-01-11
US4921035A (en) 1990-05-01
DK72688A (da) 1988-02-12
PL266276A1 (en) 1988-08-18
PL154314B1 (en) 1991-07-31
CS428287A3 (en) 1992-01-15
WO1987007544A1 (en) 1987-12-17
CS276988B6 (en) 1992-11-18
ES2004292A6 (es) 1988-12-16
JPS63503446A (ja) 1988-12-15

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Legal Events

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PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

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Effective date: 19880122

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Effective date: 19890613

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Inventor name: LEUTWILER, HANS