EP0152573B1 - Dispositif pour compacter du matériau de moulage de fonderie à l'aide d'un gaz de compression - Google Patents

Dispositif pour compacter du matériau de moulage de fonderie à l'aide d'un gaz de compression Download PDF

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Publication number
EP0152573B1
EP0152573B1 EP84114951A EP84114951A EP0152573B1 EP 0152573 B1 EP0152573 B1 EP 0152573B1 EP 84114951 A EP84114951 A EP 84114951A EP 84114951 A EP84114951 A EP 84114951A EP 0152573 B1 EP0152573 B1 EP 0152573B1
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EP
European Patent Office
Prior art keywords
pressure
accordance
piston
fact
working space
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.)
Expired
Application number
EP84114951A
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German (de)
English (en)
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EP0152573A1 (fr
Inventor
Norbert Ing. Grad. Damm
Günter Ing. grad. Müller
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.)
BMD Badische Maschinenfabrik Durlach GmbH
Original Assignee
BMD Badische Maschinenfabrik Durlach GmbH
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Application filed by BMD Badische Maschinenfabrik Durlach GmbH filed Critical BMD Badische Maschinenfabrik Durlach GmbH
Publication of EP0152573A1 publication Critical patent/EP0152573A1/fr
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Publication of EP0152573B1 publication Critical patent/EP0152573B1/fr
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C15/00—Moulding machines characterised by the compacting mechanism; Accessories therefor

Definitions

  • the invention relates to a device for compressing foundry molding material by means of compressed gas, consisting of a pressure vessel forming a pre-pressure chamber for the compressed gas, a molding space arranged underneath from a molding box with a filling frame and a model plate with a model that closes the molding box below, onto which the molding material is compressed is loosely heaped up, and a large-area valve arranged between the pressure vessel and the molding space, the closure member of which releases the valve opening in a few milliseconds with the aid of the pressure in the pressure vessel, moves into the molding space and can be brought into the closed position by means of a pressure medium cylinder.
  • outlet pressures are sought which are in the range of the pressure of operational compressed air networks in order not to have to spend too much constructive effort on the one hand for the production of compressed gas and on the other hand for the control of the pressure.
  • the device must have a closure member which on the one hand closes the largest possible cross section for overflowing the compressed gas and on the other hand has the lowest possible mass in order to release the cross section as quickly as possible.
  • This also requires opening drives which bring the closure member into the open position in a few milliseconds and thus release the cross section. The aforementioned requirements cannot be achieved with conventional valve designs.
  • the object of the invention is to further develop the device described above in such a way that an even greater opening speed for the closure member is achieved with less design effort.
  • the pressure medium cylinder not only takes on the closing function, but also the opening and damping function for the closure member.
  • the clamping device and damping device necessary in the previously described device are dispensed with.
  • this discharge speed must be> 10 m / s, that is to say in a range which is 10 times higher than the return oil speeds customary in hydraulics.
  • This significantly higher flow rate for the displacement volume can be achieved by appropriate design measures.
  • the piston speed itself can only have values in the range of approx. 5 m / sec. to reach.
  • the working space of the pressure medium cylinder has a small displacement volume of e.g. B. 150 to 500 cm 3 .
  • the drain is decoupled from the other high-pressure circuit and connected to a drain tank via a line of relatively large cross-section.
  • the flow resistance for the expiring displacement is kept as low as possible
  • the decoupling from the otherwise high pressure circuit ensures that the amount of pressure medium to be displaced is small.
  • the drain tank gives the possibility to get a quick pressure reduction on the drain side.
  • the pressure accumulator the pressure of which acts on the other side of the piston, is in the closed position of the closure member, that is to say in the raised end position of the piston under a gas pressure between 50 and 200 bar, which is directly or indirectly, for. B. a hydraulic cushion acts on the piston. From approx. 50 bar, the effect of a gas pressure cushion, which in principle is already present even at lower pressures, advantageously increases in the sense of an additional acceleration.
  • the ratio of pressure accumulator volume to displacement volume of the pressure medium cylinder is at least 5: 1.
  • the device according to the invention is further characterized by a throttle which becomes effective towards the end of the lowering movement of the piston and which ensures that the piston and thus the closure member are braked over a short distance.
  • the piston rod connecting the piston to the closure member has a section which is flared in relation to the cylinder bushing of the piston rod within the pressure medium cylinder and that the piston rod extends through the inlet and outlet opening of the working space, which in connection with the conically enlarged section the piston rod forms the throttle.
  • the damping behavior can be further optimized with additional axially notches incorporated into the conical heel.
  • the throttle braking the piston is therefore integrated in the pressure medium cylinder.
  • the fastest possible drain is favored in that the inlet and outlet opening of the working space forming part of the throttle opens into at least two inlet and outlet channels.
  • the piston has a projection which projects into the space of the pressure accumulator and which has a stop which interacts with an end position limiter for the lowering movement of the piston.
  • the high pressure source is connected to the two channels of the pressure medium cylinder via a control slide, a check valve and a branching pipe thereafter, and that the discharge tank is connected to the branch lines via a controllable check valve.
  • the branch lines have the largest possible cross-section in order to allow the pressure medium to drain off quickly.
  • control slide connects the pressure medium cylinder to the high pressure source in a first position and opens the control line of the controllable check valve so that it closes and connects the control line to the high pressure source in a second position. so that the check valve opens against the pressure in the branch line and connects the pressure medium cylinder to the drain tank.
  • Figure 2 shows an embodiment of the control of the pressure medium cylinder.
  • a pressure vessel 5 - in the illustrated embodiment for receiving compressed air - which is connected via a connection 6 from a pressure accumulator or - at low admission pressure - is fed from the company's compressed air network.
  • the pressure vessel has a plate 7 which is provided with a plurality of openings 8 in a rust-like manner in the area above the molding space.
  • a frame 9 is flanged to the underside of the base 7, to which in turn an exhaust air line with a valve 10 is connected.
  • the pressure vessel 5 with the frame 9 on the one hand and the model plate 1 with model 2, molding box 3 and filling frame 4 can be moved relative to one another in order to be able to fill the molding space with molding material. Before the compression, these two assemblies are brought together and pressed tightly together at their interface.
  • valve plate 11 sits on a guide rod 14 which merges into the piston rod 16 of the piston 15 of a pressure medium cylinder 17. This is described below with reference to FIG. 2:
  • the pressure medium cylinder 47 which corresponds to the pressure medium cylinder 17 in FIG. 1, is arranged in a high-pressure circuit, the high-pressure source being designated by 41.
  • the high-pressure source 41 This is, for example, a hydraulic pump that is fed from a tank 66.
  • the pressure medium passes via a control slide 42 and a check valve 43 into branch lines 44, which are each connected to a channel 48 in the pressure medium cylinder 47.
  • the channels 48 in turn open into a central opening 49 of the pressure medium cylinder, which establishes the connection to the working space 50 of the pressure medium cylinder.
  • the pressure medium cylinder 47 has a pressure accumulator 51 above the piston 45, which is connected to a gas pressure receiver 53 via a check valve 52.
  • the piston 45 forms the lower, movable end of the pressure accumulator 51.
  • a partition 54 is arranged within the pressure accumulator and forms a limit position for the piston 45 and thus for the closure member 11.
  • the partition wall 54 is provided with a plurality of openings in order to allow the pressure in the pressure accumulator 51 to act unhindered on the piston 45.
  • the piston in turn, is provided with a stop 56 via a shoulder 55 which rests on an elastic element 57 in the lower end position of the piston 45, that is to say in the open position of the closure member 11.
  • the piston rod 46 is provided in its area lying within the working space 50 with a conically widened section 58 which forms a kind of throttle when the piston 45 is lowered in connection with the opening 49. Furthermore, the working space 50 of the pressure medium cylinder 47 can be connected via a line 59 to a further fine throttle 60, which in turn is connected to one of the two branch lines 44.
  • the branch lines 44 are connected via a controllable check valve 61, the control line of which can be connected to the high-pressure source 41 via the control slide 42, to an outlet tank 63, the outlet 64 of which opens into the system tank 66 and which is also equipped with a vent 65.
  • the control slide 42 In order to bring the closure member 11 from the open position shown on the right in FIG. 1 to the closed position (left half of FIG. 1), the control slide 42 is brought into the position "B". In this position, the connection between the high-pressure source 41 and the working space 50 of the pressure medium cylinder 47 is established by opening the check valve 43. At the same time, the control line 62 of the controllable check valve 61 is connected to the system tank, ie without pressure, so that the check valve 61 closes. The pressure medium flows through the branch lines 44 and the channels 48 into the working space 50, lifts the piston 45 and thus the piston rod 46 and the guide rod 14 with the closure member 11 until it has finally reached the closed position (left half of FIG. 1).
  • the model plate 1 with the filled molding box 3 and filling frame 4 is clamped to the frame 9.
  • the valve 10 is in the closed position.
  • the medium in the pressure accumulator 51 is prestressed at the same time. Any leakage losses in the pressure accumulator 51 are supplemented by the print template 53.
  • the pressure in the pressure accumulator 51 increases, for example, to approximately 100 bar.
  • the closure member 11 is brought into the open position (right half of FIG. 1).
  • the control slide 42 in the position "A" switched.
  • the pressure of the high pressure source 41 is then present in the control line 62, so that the check valve 61 opens.
  • the pressure medium runs out of the working space 50 under the action of the pressure in the pressure accumulator 51 via the check valve 61 into the discharge tank 63.
  • the outlet cross-section between the piston rod 46 and the outlet opening 49 is reduced by the conical section 58 on the piston rod 46, so that the piston 45 and thus the closure member 11 are braked.
  • the pressure medium to be displaced runs out of the working space 50 at a speed of more than 10 m / s, preferably between 20 and 30 m / s.
  • the drain tank 63 can be vented between the compression cycles via the line 65, so that its contents can flow into the system tank 66.

Claims (14)

1. - Dispositif pour compacter du matériau de moulage de fonderie à l'aide d'un gaz de compression, composé d'un réservoir sous pression (5) constituant une chambre de précompression, d'un volume de moulage disposé en dessous de celle-ci et comprenant un châssis de moulage (3) avec hausse (4) et une plaque-modèle (1) avec modèle (2) qui assure la fermeture inférieure du châssis de moule et sur laquelle le matériau de moulage est versé en vrac avant le compactage, et d'une vanne de grande section placée entre le réservoir sous pression et le volume de moulage, dont l'organe d'obturation (11) libère l'ouverture (8) de la vanne en quelques millisecondes, avec le concours de la pression à l'intérieur du réservoir sous pression (5), en se déplaçant vers l'intérieur du volume de moulage et peut être amené, au moyen d'un cylindre compresseur, dans la position de fermeture, l'espace de travail (50) du cylindre compresseur (47) limité par un piston (45) étant raccordé à une source de haute pression (41), le piston (45) formant, avec sa face opposée à l'espace de travail (50), la fermeture mobile d'un accumulateur de pression (51) alimenté en gaz et l'espace de travail comportant un écoulement (44, 48, 61, 63) qui est conformé de telle façon que le fluide hydraulique s'échappe à une vitesse e 10 m/s, avec accélération simultanée du piston (45) aussi bien que de l'organe d'obturation (11) dans la position d'ouverture sous l'effet de la pression régnant dans l'accumulateur de pression (51).
2. - Dispositif selon la revendication 1, caractérisé en ce que l'espace de travail (50) du cylindre compresseur (47) présente un faible volume de déplacement, par exemple entre 150 et 500 cm3.
3. - Dispositif selon l'une des revendications 1 ou 2, caractérisé en ce que l'écoulement (44, 48, 49) de l'espace de travail (50) est découplé du reste du circuit hydraulique à haute pression (41) par l'intermédiaire d'éléments de commutation (61, 43) et relié à un collecteur (63) par l'intermédiaire d'une conduite (44) ayant une section relativement grande.
4. - Dispositif selon l'une quelconque des revendications 1 à 3, caractérisé en ce que la pression de la source de haute pression (51) se situe entre 100 et 300 bars.
5. - Dispositif selon l'une quelconque des revendications 1 à 4, caractérisé en ce que, dans la position de fermeture de l'organe d'obturation (11), l'accumulateur de pression (51) est soumis directement ou indirectement à une pression de gaz comprise entre 50 et 200 bars.
6. - Dispositif selon l'une quelconque des revendications 1 à 5, caractérisé en ce que le rapport entre le volume de l'accumulateur de pression et le volume de déplacement du cylindre compresseur (47) est d'au moins 5 : 1.
7. - Dispositif selon l'une quelconque des revendications 1 à 6, caractérisé en ce qu'il comporte un dispositif d'étranglement (49, 58, 59, 60) qui devient efficace vers la fin du mouvement de descente du piston (45).
8. Dispositif selon la revendication 7, caractérisé en ce que la tige de piston (46) qui relie le piston (45) à l'organe d'obturation (11) présente, à l'intérieur du cylindre compresseur (47), une section (58) évasée de manière conique par rapport à la traversée de cylindre de la tige de piston et que la tige de piston (46) traverse l'ouverture d'admission et d'écoulement (49) de l'espace de travail (50) qui, en combinaison avec la section à évasement conique (58) de la tige de piston (46), constitue le dispositif d'étranglement.
9. - Dispositif selon l'une quelconque des revendications 1 à 8, caractérisé en ce que l'ouverture d'admission et d'écoulement (49) de l'espace de travail (50) débouche dans au moins deux canaux d'admission et d'écoulement (48).
10. - Dispositif selon l'une quelconque des revendications 1 à 9, caractérisé en ce que le piston (45) présente un embout (55) qui dépasse dans le volume de l'accumulateur de pression (51) et qui est pourvu d'une butée (56) laquelle coopère avec un limiteur de fin de course (54, 57) pour le mouvement de descente du piston (45).
11. - Dispositif selon l'une quelconque des revendications 1 à 10, caractérisé en ce que la source de haute pression (41) est reliée, par l'intermédiaire d'une vanne-pilote (42), d'un clapet antiretour (43) et d'une conduite circulaire (44), aux deux canaux (48) du cylindre compresseur (47), et que le collecteur (63) est raccordé, par l'intermédiaire d'un clapet antiretour (61) pouvant être commandé dans le sens de l'ouverture, à la conduite circulaire (44).
12. - Dispositif selon la revendication 11, caractérisé en ce que la vanne-pilote (42) établit, dans une première position, la liaison entre le cylindre compresseur (47) et la source de haute pression (41) et décharge la conduite de pilotage (62) du clapet antiretour (61) pouvant être commandé dans le sens de l'ouverture de telle façon que celui-ci se ferme et relie, dans une deuxième position, la conduite de pilotage (62) à la source de haute pression (41) de sorte que le clapet antiretour (61) s'ouvre contre la pression dans la conduite circulaire (44) et relie le cylindre compresseur (47) au collecteur (63).
13. - Dispositif selon l'une quelconque des revendications 1 à 12, caractérisé en ce que l'espace de travail (50) communique, par l'intermédiaire d'un clapet antiretour (61) pouvant être commandé dans le sens de l'ouverture, avec un collecteur (63) qui est équipé d'un système de mise à l'atmosphère (65).
14. - Dispositif selon la revendication 13, caractérisé en ce que le contenu du collecteur (63) s'écoule dans un collecteur (66) du système.
EP84114951A 1983-12-09 1984-12-07 Dispositif pour compacter du matériau de moulage de fonderie à l'aide d'un gaz de compression Expired EP0152573B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3344520 1983-12-09
DE19833344520 DE3344520A1 (de) 1983-12-09 1983-12-09 Vorrichtung zum verdichten von giesserei-formstoff mittels druckgas

Publications (2)

Publication Number Publication Date
EP0152573A1 EP0152573A1 (fr) 1985-08-28
EP0152573B1 true EP0152573B1 (fr) 1988-04-27

Family

ID=6216456

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84114951A Expired EP0152573B1 (fr) 1983-12-09 1984-12-07 Dispositif pour compacter du matériau de moulage de fonderie à l'aide d'un gaz de compression

Country Status (6)

Country Link
US (1) US4619307A (fr)
EP (1) EP0152573B1 (fr)
JP (1) JPS61500601A (fr)
DD (1) DD229324A5 (fr)
DE (2) DE3344520A1 (fr)
WO (1) WO1985002568A1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3836876C2 (de) * 1988-10-29 1994-06-09 Badische Maschf Gmbh Verfahren und Vorrichtung zum Verdichten von Gießerei-Formstoff
CH686412A5 (de) * 1992-03-10 1996-03-29 Fischer Georg Giessereianlagen Verfahren zum Verdichten von Formsand fuer Giessformen.

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0131723A1 (fr) * 1983-06-18 1985-01-23 BMD Badische Maschinenfabrik Durlach GmbH Dispositif pour le serrage de matière de moulage de fonderie à l'aide de gaz comprimé

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1961234C3 (de) * 1969-12-05 1975-02-06 Kramatorskij Nautschno-Issledowatel' Skij I Projektno-Technologitscheskij Institut Maschinostrojenija, Kramatorsk (Sowjetunion) Verfahren und Vorrichtung zum Verdichten von GieBereiformmassen
SU665977A1 (ru) * 1976-04-08 1979-06-08 Краматорский Научно-Исследовательский И Проектно-Технологический Институт Машиностроения Устройство дл изготовлени литейных форм
SU793696A1 (ru) * 1979-03-19 1981-01-07 Краматорский Научно-Исследовательскийи Проектно-Технологический Институтмашиностроения Импульсна головка
CH642288A5 (de) * 1980-02-18 1984-04-13 Fischer Ag Georg Verfahren und einrichtung zum verdichten von formstoff, insbesondere fuer giessformen.
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
DE3149172A1 (de) * 1981-12-11 1983-06-30 Georg Fischer AG, 8201 Schaffhausen "verfahren zur herstellung von formkoerpern mittels gasdruck"
EP0084627B1 (fr) * 1981-12-28 1986-05-07 BMD Badische Maschinenfabrik Durlach GmbH Dispositif pour comprimer du matériel de moulage pour fonderies
CH657790A5 (de) * 1982-10-27 1986-09-30 Fischer Ag Georg Vorrichtung zum verdichten von koernigen formstoffen.

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0131723A1 (fr) * 1983-06-18 1985-01-23 BMD Badische Maschinenfabrik Durlach GmbH Dispositif pour le serrage de matière de moulage de fonderie à l'aide de gaz comprimé

Also Published As

Publication number Publication date
DD229324A5 (de) 1985-11-06
EP0152573A1 (fr) 1985-08-28
DE3344520C2 (fr) 1989-01-12
DE3470673D1 (en) 1988-06-01
US4619307A (en) 1986-10-28
WO1985002568A1 (fr) 1985-06-20
DE3344520A1 (de) 1985-06-20
JPS61500601A (ja) 1986-04-03

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