WO2008141754A1 - Dispositif et procédé d'alimentation d'un chargeur de sable à noyaux dans une machine à tirer les noyaux au moyen d'un gaz de tir humidifié - Google Patents

Dispositif et procédé d'alimentation d'un chargeur de sable à noyaux dans une machine à tirer les noyaux au moyen d'un gaz de tir humidifié Download PDF

Info

Publication number
WO2008141754A1
WO2008141754A1 PCT/EP2008/003832 EP2008003832W WO2008141754A1 WO 2008141754 A1 WO2008141754 A1 WO 2008141754A1 EP 2008003832 W EP2008003832 W EP 2008003832W WO 2008141754 A1 WO2008141754 A1 WO 2008141754A1
Authority
WO
WIPO (PCT)
Prior art keywords
gas
humidified
core
shot
temperature
Prior art date
Application number
PCT/EP2008/003832
Other languages
German (de)
English (en)
Inventor
Andreas Eichelberger
Werner Pichler
Original Assignee
Hottinger Maschinenbau Gmbh
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 Hottinger Maschinenbau Gmbh filed Critical Hottinger Maschinenbau Gmbh
Publication of WO2008141754A1 publication Critical patent/WO2008141754A1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C15/00—Moulding machines characterised by the compacting mechanism; Accessories therefor
    • B22C15/23—Compacting by gas pressure or vacuum
    • B22C15/24—Compacting by gas pressure or vacuum involving blowing devices in which the mould material is supplied in the form of loose particles

Definitions

  • the present invention relates to a shot-gas supply apparatus, and more particularly to a shot-gas supply apparatus which makes it possible to provide a pressurized gas of predetermined adjustable humidity to a core shooting facility.
  • a so-called “core sand” is filled into a mold having a cavity having the shape of the sand core to be formed.
  • the core sand is usually introduced via a plurality of distributed openings arranged, so-called “shot openings” in the mold.
  • shots openings so-called “shot openings” in the mold.
  • a nozzle When filling in each of the firing openings, a nozzle (“firing nozzle") is introduced, through which the core sand is introduced into the cavity, which is usually carried by compressed air or pressurized gas at high speed, so that the core sand is also injected.
  • the core sand itself is normally stored within a closed volume on the side of the shot nozzle facing away from the mold, the so-called “shot hood.”
  • the core sand volume is suddenly and briefly recorded (within about 500 ms to 800 ms)
  • pressurizing the core sand is introduced into the mold, wherein the core sand is completely penetrated by the gas, so that the majority of the introduced gas through the core sand and through the weft nozzles flows into the mold, from which the shot gas can escape via vents.
  • this activating gas as well as the use of organic binders leads to a non-negligible burden on the workplace or the environment, so that the development of core sands with inorganic binders, such as water glass, have been promoted.
  • the inorganic binders cure under the influence of supplied heat so that an activating, polluting gas can be dispensed with.
  • the filled with the core sand mold is heated, or the core sand is introduced into an already preheated mold. Therefore, a heat effect on the core sand before the actual introduction into the molded part must be avoided in order to prevent premature curing of the core sand.
  • Such premature curing for example in the firing nozzles, leads inevitable that the core shooter is clogged and thus the core manufacturing process is interrupted.
  • Curing can be prevented by moistening the sand, whereby the amount of moisture supplied must be precisely metered to allow the production of high quality sand cores. If too little moisture is supplied per unit of time or per volume of sand, premature hardening and thus clogging of the apparatus still occurs at the points which are particularly exposed to temperature. However, if too much moisture is added, condensation of the moisture may occur, leading to the formation of drops of the liquid supplied, which are introduced by the shot nozzles into the mold and lead to voids in the sand core. This inevitably leads to a deterioration in the quality of the sand cores and thus an increase in rejects in the foundry.
  • the German utility model 202006010504 Ul proposes to carry out a compressed air humidification within a compressed air tank, in which the firing air of the core shooting machine is stored, that there is liquid water within the compressed air tank.
  • the compressed air is introduced either above the water level in the compressed air tank or below the water level, so that the newly introduced compressed air is first passed through the water to be moistened during the introduction.
  • the moisture or water taken up by the compressed air is to be returned to the core sand mixture (sand, binder and possibly also activators or promoters) during the firing process.
  • the entrainment of water is also favored, among other things, when trying to moisten the air in the highly dynamic range of the system.
  • a shot process within which the core sand is transported into the mold, lasts only between 500 ms to 800 ms.
  • the compressed air tank is thus partially emptied and its content is transported via the firing nozzles into the molded part.
  • high gas velocities also occur within the evacuated pressure vessel, which in addition result in considerably more water being transported by the compressed air than would be the case with a thermodynamic equilibrium at the dew point, since the water can be carried along by the rapidly flowing gas.
  • the present invention has for its object to provide a shot gas supply device, which makes it possible to provide shot gas with a predetermined humidity to use this within a core shooter.
  • Some exemplary embodiments of the invention are based on the finding that a core sand hopper can be supplied with a moistened gas of predetermined humidity if a shot gas supply device is used which has a compressed gas reservoir and a gas humidification system. has device.
  • the compressed gas reservoir has a gas outlet for supplying the core sand magazine and a gas inlet for filling the compressed gas reservoir.
  • the gas humidifying device for humidifying the gas is arranged in a gas feed to the gas inlet of the compressed gas reservoir. That is, the gas is moistened before it is stored in the compressed gas reservoir.
  • the moistening therefore takes place at a point in the gas guide in which no discontinuous states prevail.
  • the location of humidification is therefore not in the high-dynamic range of the system, there are no abrupt changes in the flow rate of the gas or gas pressure instead.
  • the gas is completely saturated with the moisture, ie, the gas is moistened until at the temperature of the gas, the thermodynamic equilibrium between the liquid and the gaseous phase of the liquid used for moistening, established.
  • an already pressurized gas is humidified. This means that a gas which is under pressure above the ambient pressure is moistened.
  • a gas humidifier comprises temperature control means for varying the temperature of the gas to precisely adjust the dew point and thus the amount of moisture that can be taken up and transported by the gas according to the laws of thermodynamics.
  • gas is to be understood as meaning any gas mixture which can be used to supply core shooting machines. It does not have to be a monoatomic gas, but also any gas mixtures, such as air, in question and should be understood by the term gas.
  • moisture is to be understood, which should not be understood as limited to water.
  • moisture should be understood to mean the gaseous phase of any liquid which is suitable for mixing with core sands.
  • This can be, for example, water or an activator / moderator that can be added to core sands in order, depending on its concentration, to accelerate or possibly also to prevent hardening of the core sand.
  • the temperature control device of the gas humidifier has a heating element in the form of a microwave radiator. This has the great advantage that the entire volume within the gas humidification device can be uniformly heated by means of the microwaves, so that it is ensured that no temperature gradients can occur within the gas humidification device. As a result, a uniform humidification of the gas can be ensured.
  • both the temperature of the compressed gas reservoir as well as the temperature of the gas supply between the gas humidifier and the compressed gas reservoir regulated at a temperature or heated to a temperature which is above the temperature which is set within the gas humidifier (dew point temperature).
  • FIG. 1 shows a schematic representation of a shot gas supply device
  • FIG. 2 shows a schematic representation of a core shooter
  • FIG. 3 shows a further schematic representation of a core shooter
  • Fig. 4 is a schematic representation of a method for supplying a core sand magazine with humidified gas.
  • the shotgas supply device 10 for supplying a core sand hopper of a core shooter with a pressurized humidified gas of predetermined humidity.
  • the shotgas supply device 10 comprises a compressed gas reservoir 12 for the humidified gas and a gas humidification device 14, which is arranged in a gas duct to a gas inlet 16 of the compressed gas reservoir 12.
  • the compressed gas reservoir 12 has a remote gas outlet 18 for supplying the core sand magazine.
  • the humidification of the gas prior to the storage of the humidified gas in the compressed gas reservoir 12 is carried out in order to make it possible to precisely adjust the humidification, ie the amount of liquid transported by the gas.
  • the compressed air or gas humidification system is installed in the supply line to the compressed gas tank (or compressed air reservoir, boiler, buffer, reservoir) required for the core production process.
  • the compressed air, or the gas or gas mixture is regulated and tempered (ie heated or cooled) in the supply line to the compressed air tank 12 by means of suitable apparatuses and moistened with a liquid such as, for example, softened / demineralized / demineralised water, that the air or the gas is always saturated.
  • the humidification of the gas in the gas humidifying device 14 is thus carried out in some embodiments so that the volume of the gas humidifier 14 and the gas located within this volume are at a temperature corresponding to the desired humidification of the gas, if this is up to its (temperature-dependent) saturation is laden with moisture.
  • a heater may be mounted within the gas humidifier 14 to increase the amount of water taken up or the liquid received. Should it require the process, cooling can alternatively be used be provided to transport a smaller amount of moisture than would be the case because of the ambient temperatures or the temperature of the supplied gas without cooling.
  • the moisture transported by the gas can be adjusted precisely by means of a simple temperature control, without falsifying the amount of moisture transported by the highly dynamic processes taking place within the compressed gas reservoir 12.
  • the gas supply to the gas inlet 16 and the compressed gas reservoir 12 optionally with a temperature control device 20 may be coupled to keep the temperature of the gas supply and the compressed gas reservoir 12 above the dew point temperature of the humidified gas.
  • the purpose of such a heat tracing is to keep the respective required saturation temperature of the compressed air / gas / gas mixture and thus the moisture content of the compressed air / gas / gas mixture largely constant and to prevent the humidity from condensing.
  • FIG. 2 shows an embodiment of a core shooter including a shot gas supply device 10 as shown in FIG.
  • the core shooter further includes a core sand hopper 24 within which the core sand is located and which is connected to the gas outlet 18 of the compressed gas reservoir 12.
  • the core sand hopper 24 includes the core sand, which can be introduced via the located on the bottom of the core sand hopper 24 shot nozzles 26 a to 26 c in a mold, not shown. If the ambient conditions make it necessary to provide additional heat tracing and thermal insulation which supports the desired process result, a gas connection 28 between the compressed gas reservoir 12 and the core sand hopper 24 can also be connected to a temperature control in order to keep the temperature of the gas connection 28 above the dew point temperature ,
  • the pipelines between the humidifying unit and the compressed air tank and between the compressed air tank and the shooting device and the compressed air tank itself are insulated and provided with a heater to ensure that the moisture content of the gas which is exactly in the gas humidifying device 14 is not falsified by condensation of moisture on the way to the core sand magazine 24.
  • FIG. 3 shows a detailed representation of a core shooting machine, based on the schematic representation of FIG. 2. Therefore, functionally identical elements are provided with the same reference character, so that the descriptions of similar or functionally identical elements can also be mutually applied to one another. This applies in the above for all functionally similar or identical components in different figures.
  • a core shooting machine which uses air as a shot gas and demineralized water as a liquid for humidification.
  • the gas humidifier 14 includes a water softener 40 to to generate the demineralised water used for humidification on site.
  • the wetting air to be moistened is supplied to the gas moistening device 14 via a valve 42 from an external compressed air supply.
  • the moistened shot air is conducted via a gas feed 44 to the gas inlet 16 of the compressed gas reservoir 12.
  • the sand magazine 24 shown in FIG. 3 has two separately controllable partial magazines, so that by means of the sand magazine 24 at the same time two different molding tools can be filled with molding sand.
  • two gas feeds 46a and 46b are provided in FIG. 3 between the compressed gas reservoir 12 and the sand hopper 24, these firing valves 48a and 48b associated with the gas connections each having a chamber of the sand hopper 24 are connected.
  • Gas supply 44 and the gas connections 46a and 46b and the compressed gas reservoir 12 are connected in the embodiment shown in Fig. 3 with a schematically illustrated temperature control device 20 to maintain the temperature of these components at a temperature above the dew point of the humidified gas.
  • vent valves 50a and 50b are further provided, which are connected to their respective associated chambers of the sand hopper 24.
  • a shot vent cleaning valve 52 is connected to the sand hopper 24 and an external pressurized gas source. Via the line between the Schussentlformatung- cleaning valve 52 and the sand hopper 24 also a pressure switch 54 is also connected to the sand hopper, which monitors the pressure in the sand hopper 24 during the vent after the shot. By means of the pressure switch 54 so the venting process is monitored, so for example from a pressure level in the sand hopper 24 of about 0.1 bar overpressure, the vent can be considered complete, whereupon then the sand hopper 24 with firing hood is driven up and to the side. At the same time, a possible gasification device can be moved over the tool in order to be braced with it and, for example, to conduct hot air into the tool for hardening the cores (possibly also in addition to tool heating).
  • the shot vent cleaning valve 52 is triggered synchronously with the shot, i. Through a port Ll additional compressed air is blown into the sand hopper 24 during the firing process and by time delay also something in the venting time. As a result, the lines and the pressure switch 54 sand magazine remain free of contamination.
  • Fig. 3 shows in dashed line pneumatic control lines 56, which serve to control the individual valves or to provide a required for their operation operating pressure.
  • the operating pressure is adjusted by means of a pressure regulator 58.
  • the control may be purely pneumatic, but other control mechanisms may be used, such as electrical signals or messages transmitted on a data bus.
  • the gas humidifying device 14 has a closed volume 60 through which the gas to be humidified or the air to be humidified is passed. Within this volume 60, an evaporation body 62 is arranged, which is wetted with the water of the water softening system 40 and preferably has a large surface, so that the evaporation of the water is promoted. Furthermore, the gas humidifying device 14 has a schematically illustrated temperature control device 64 for varying the temperature of the air or the humidified air.
  • the temperature Gel Hughes 64 can be implemented in various ways, such as by a resistance wire heater or a microwave.
  • the supply of softened water is controlled by the volume 60 containing a sensor that is sensitive to the liquid collecting at a bottom of the volume 60. If no liquid is detected, additional water is added.
  • This has the further advantage that the presence of a liquid phase is also an indication that the gas in the volume 60 at the set temperature is saturated with moisture.
  • the presence of the liquid within the volume 60 may thus be used in another embodiment to regulate the flow rate of the gas to ensure that the gas within the residence time in the volume 60 is saturated.
  • Fig. 3 The entire system shown in Fig. 3, which adjoins the gas humidifier 14, i. that is, the gas supply 44, the compressed gas reservoir 12, and the gas connections 46a and 46b are provided with a heater connected to a temperature control to prevent condensation of liquid from the gas. Both the heating and the temperature control are shown in Fig. 3 only schematically.
  • the humidified air is transported via the gas supply 44 into the compressed gas reservoir 12, wherein the pressure in the gas feed 44 is controlled by a pressure regulator 66 and kept constant.
  • a further pressure regulator 68 controls the pressure of the gas within the compressed gas reservoir 12. This allows the pressure to be adjusted to the required conditions, such as the core sand used or the desired speed of filling the molding tools. len.
  • an excessively high pressure can be prevented by opening a venting valve when a permissible maximum pressure is exceeded. Pressures in which a transfer of the sand reliably succeeds, for example, between 3 bar and 8 bar.
  • the shot valves 48a and 48b are opened, so that the humidified gas from the compressed gas reservoir 12 flows into the sand hopper 24 and shoots the core sand into the molds by the sudden overpressure.
  • FIG. 4 shows a schematic representation of an example of a method for supplying a core sand magazine of a core shooter with a moistened gas of predetermined moisture.
  • a humidifying step 70 the gas is humidified to the predetermined humidity to form humidified gas.
  • the humidified gas is stored in a storage step to make it available to a core sand hopper.
  • the fact that the gas is first moistened before it is stored with precisely set humidity in a reservoir in which highly dynamic conditions prevail makes it possible to reproduce zierbar and precisely metered to adjust that amount of moisture that requires the subsequent process, or can prevent premature curing of a fed with the humidified gas core sand mixture.
  • the humidification of the gas was mainly represented by using an evaporative body, it is not absolutely necessary to use an evaporative body in the context of the invention. Rather, the gas can be humidified in any other way that allows reproducible humidification or saturation of the gas used. It is conceivable, for example, fine mist of liquid to be used for moistening, through which the gas can be passed. Furthermore, the gas can be passed over a liquid level, for example, if sufficient time is available for the thermodynamic equilibrium to form above the surface of the liquid level, so that the gas is saturated at a set temperature.
  • any heating or cooling device can be used, which allows the gas to be heated to an adjustable temperature or to cool over the Temperature set the recorded moisture content.
  • both cooling and heating may be provided within the gas humidifier to provide a system that can flexibly respond to any possible environmental condition.

Abstract

Un dispositif d'alimentation en gaz de tir (10) servant à alimenter un chargeur de sable à noyaux d'une machine à tirer les noyaux, au moyen d'un gaz humidifié sous pression, présente un réservoir à gaz comprimé (12) pour le gaz humidifié, comportant une sortie de gaz (18) pour l'alimentation du chargeur de sable à noyaux, et une entrée de gaz (16) pour le remplissage du réservoir à gaz comprimé. En outre, le dispositif d'alimentation en gaz de tir (10) présente un dispositif d'humidification du gaz (14) qui est disposé dans une amenée de gaz vers l'entrée de gaz (16) et qui humidifie le gaz à une humidité prédéterminée, en vue de former le gaz humidifié.
PCT/EP2008/003832 2007-05-23 2008-05-13 Dispositif et procédé d'alimentation d'un chargeur de sable à noyaux dans une machine à tirer les noyaux au moyen d'un gaz de tir humidifié WO2008141754A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102007023883.7 2007-05-23
DE102007023883A DE102007023883A1 (de) 2007-05-23 2007-05-23 Vorrichtung und Verfahren zum Versorgen eines Kernsandmagazins bei der Kernschiessmaschine mit befeuchtetem Schussgas

Publications (1)

Publication Number Publication Date
WO2008141754A1 true WO2008141754A1 (fr) 2008-11-27

Family

ID=39717672

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2008/003832 WO2008141754A1 (fr) 2007-05-23 2008-05-13 Dispositif et procédé d'alimentation d'un chargeur de sable à noyaux dans une machine à tirer les noyaux au moyen d'un gaz de tir humidifié

Country Status (2)

Country Link
DE (1) DE102007023883A1 (fr)
WO (1) WO2008141754A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102601319A (zh) * 2012-03-26 2012-07-25 苏州明志科技有限公司 一种射筒

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
PL2916976T3 (pl) 2013-10-19 2017-08-31 Peak Deutschland Gmbh Sposób wytwarzania traconych rdzeni lub elementów formowanych do produkcji odlewów

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE202006010504U1 (de) * 2006-07-05 2006-08-31 Hydro Aluminium Mandl&Berger Gmbh Vorrichtung zum Druckbeaufschlagen von Kernsand in einer Kernschießmaschine und Kernschießmaschine

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4150953A (en) * 1978-05-22 1979-04-24 General Electric Company Coal gasification power plant and process
DD154430A3 (de) * 1980-02-14 1982-03-24 Helmut Crucius Formmaschine

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE202006010504U1 (de) * 2006-07-05 2006-08-31 Hydro Aluminium Mandl&Berger Gmbh Vorrichtung zum Druckbeaufschlagen von Kernsand in einer Kernschießmaschine und Kernschießmaschine

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102601319A (zh) * 2012-03-26 2012-07-25 苏州明志科技有限公司 一种射筒

Also Published As

Publication number Publication date
DE102007023883A1 (de) 2008-11-27

Similar Documents

Publication Publication Date Title
DE102015013131B4 (de) Vorrichtung und Verfahren zur Herstellung von aus einem Partikelschaum bestehenden Formteilen
EP3126124A1 (fr) Procédé et dispositif pour l'impression 3d avec mise en oeuvre climatisée du procédé
EP3544782A1 (fr) Procédé et dispositif de fabrication d'une pièce moulée constituée d'une mousse particulaire
DE3243632A1 (de) Verfahren und vorrichtung zur sinterung insbesondere unterschiedlicher formlinge aus insbesondere verschiedenartigen schaeumbaren kunststoffen
WO2019025087A1 (fr) Dispositif et procédé de fabrication d'une pièce en mousse particulaire
WO2008141754A1 (fr) Dispositif et procédé d'alimentation d'un chargeur de sable à noyaux dans une machine à tirer les noyaux au moyen d'un gaz de tir humidifié
DE102016014065A1 (de) Verfahren und Vorrichtung zur Herstellung eines aus einem Partikelschaum bestehenden Formteils
DE2833305A1 (de) Verfahren und vorrichtung zum aushaerten von aus sand hergestellten kernen und/oder formen, die zum giessen von formkoerpern aus metall verwendung finden
EP1444063B1 (fr) Procede et machine a tirer les moules pour produire des pieces moulees, telles que des noyaux de coulee, pour des moules utilises pour couler des metaux en fusion
EP0310802B1 (fr) Procédé et dispositif pour la fabrication de noyaux et moules de fonderie en sable, utilisant un liant
CH235339A (de) Vorrichtung zum Herstellen von Kunstharzpressmischungen.
DE3502006A1 (de) Verfahren zum schaeumen und sintern von kunststoffen
DE202006010504U1 (de) Vorrichtung zum Druckbeaufschlagen von Kernsand in einer Kernschießmaschine und Kernschießmaschine
DE19701595A1 (de) Anlage für die Vorwärmung einer Preßgutmatte im Zuge der Herstellung von Holzwerkstoffplatten, insbesondere von Spanplatten
DE10144391C1 (de) Verfahren und Formschießmaschine zum Herstellen von Formteilen, wie Gießkernen, für Gießformen zum Vergießen von Metallschmelze
DE1604943A1 (de) Verfahren und Vorrichtung zum Trocknen von aus keramischen Massen geformten Gegenstaenden
DE2236771C3 (de) Verfahren und Vorrichtung zum Herstellen eines Formteils aus geschäumtem Polystyrol
EP2308576A1 (fr) Evaporateur
WO2020043714A1 (fr) Procédé d'alimentation en gaz pour la fabrication de noyaux de coulée dans un matériau de moulage introduit dans une boîte à noyau, au moyen d'un gaz catalytique
EP1225991B1 (fr) Procede pour le retraitement de sable de fonderie
DE2139236C3 (de) Verfahren zur Luftbefeuchtung
DE3010704C2 (de) Vorrichtung zur Trockenkühlung von Koks
DE102020003820A1 (de) Verfahren zum Rückgewinnen von Amin
DE1479763C (de) Verfahren zum Kühlen der Formteile von Form- oder Gießmaschinen zum Verarbeiten von thermoplastischem Kunststoff
DE60223354T2 (de) Vorrichtung zum erhitzen von maschinenelementen zur verarbeitung von synthetischen- oder natur- harzen oder kautschuken

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 08758491

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 08758491

Country of ref document: EP

Kind code of ref document: A1