EP0120222A2 - Heat-insulated bottom of a cylinder head of a piston engine - Google Patents
Heat-insulated bottom of a cylinder head of a piston engine Download PDFInfo
- Publication number
- EP0120222A2 EP0120222A2 EP84100984A EP84100984A EP0120222A2 EP 0120222 A2 EP0120222 A2 EP 0120222A2 EP 84100984 A EP84100984 A EP 84100984A EP 84100984 A EP84100984 A EP 84100984A EP 0120222 A2 EP0120222 A2 EP 0120222A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- cylinder head
- zirconium oxide
- heat
- aluminum titanate
- insulating component
- 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
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
- F02F1/00—Cylinders; Cylinder heads
- F02F1/24—Cylinder heads
- F02F1/26—Cylinder heads having cooling means
- F02F1/28—Cylinder heads having cooling means for air cooling
- F02F1/30—Finned cylinder heads
- F02F1/32—Finned cylinder heads the cylinder heads being of overhead valve type
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B77/00—Component parts, details or accessories, not otherwise provided for
- F02B77/02—Surface coverings of combustion-gas-swept parts
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
- F02F7/00—Casings, e.g. crankcases or frames
- F02F7/0085—Materials for constructing engines or their parts
- F02F7/0087—Ceramic materials
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B1/00—Engines characterised by fuel-air mixture compression
- F02B1/02—Engines characterised by fuel-air mixture compression with positive ignition
- F02B1/04—Engines characterised by fuel-air mixture compression with positive ignition with fuel-air mixture admission into cylinder
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
- F02F1/00—Cylinders; Cylinder heads
- F02F1/24—Cylinder heads
- F02F2001/249—Cylinder heads with flame plate, e.g. insert in the cylinder head used as a thermal insulation between cylinder head and combustion chamber
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
- F02F7/00—Casings, e.g. crankcases or frames
- F02F7/006—Camshaft or pushrod housings
- F02F2007/0063—Head bolts; Arrangements of cylinder head bolts
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
- F05C2201/00—Metals
- F05C2201/04—Heavy metals
- F05C2201/0403—Refractory metals, e.g. V, W
- F05C2201/0415—Zirconium
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
- F05C2201/00—Metals
- F05C2201/04—Heavy metals
- F05C2201/043—Rare earth metals, e.g. Sc, Y
Definitions
- the present invention relates to the cylinder head of a piston engine with a heat-insulating component made of aluminum titanate, which is produced by sintering and has openings for valves, spark plugs or injection nozzles.
- DE-OS 28 21 506 has already proposed covering the inner surface of a cylinder head with a composite insulating plate.
- the composite insulating plate described consists of an actual insulating layer and a metallic support plate firmly connected to it.
- the insulating layer faces the combustion chamber and consists either of quartz glass, silicon nitride or silicon carbide and is either melted or sintered onto the metallic support plate or the insulating layer has a multilayer structure with a particularly porous intermediate layer, which is preferably formed from beads of the insulating material.
- a disadvantage of such a cylinder head is that the usual arrangement of a plurality of separate openings for valves, spark plugs and injection nozzles is difficult and, as a result, a single opening must be provided in the composite insulating plate.
- Another disadvantage lies in the complicated structure, in particular in the fact that the actual insulating layer is metallic due to its low strength Support plate needed.
- a cylinder head has been known in which a heat-resistant body made of silicon nitride is inserted into a heat-insulating component made of aluminum titanate and this composite part is shrunk into a metallic support body which may be formed by the cylinder head.
- the heat-resistant body forming the bottom of the cylinder head faces the combustion chamber and protects the heat-insulating component from mechanical stress.
- the heat-insulating component has the shape of a circular disk with a collar attached on the edge to accommodate the heat-resistant body.
- the multilayer structure of the individual components made of different materials is also disadvantageous here, which is explained by the low strength of the aluminum titanate.
- Another disadvantage is that the composite part consisting of a heat-insulating component and a heat-resistant body takes up additional space in the cylinder head and thereby impairs the complicated designs of the cooling water ducts.
- Another disadvantage arises from the fact that the cylinder head cannot be sealed against the cylinder liner due to the low strength of the aluminum titanate in the area of the aluminum titanate component, so that the seal is made on the heat-conducting body with good thermal conductivity with the disadvantage of forming a thermal bridge.
- Aluminum titanate is not possible because, for design reasons, the valve holes have to be led to the edge of the component. Since aluminum titanate has a low modulus of elasticity, it is necessary to heat the cylinder head relatively high to shrink the composite part, which has to be considered a further disadvantage.
- the object of the present invention is to overcome the existing disadvantages and to provide a satisfactory insulating effect in the cylinder head to provide a heat-insulating component that can be used in the cylinder head without thermal bridges to the cylinder head or engine block, and also via one has a simple structure and a low overall height, so that the formation of cooling water channels is not impeded, at least in this critical area adjacent to the combustion chamber. 'Further to the heat insulating member having a sufficient resistance to mechanical forces, in particular compression forces.
- Another object of the invention is to ensure that the component is firmly seated in the cylinder head and at the same time to develop a simple mounting option for the heat-insulating component.
- the invention seeks to create a possibility that enables the heat-insulating component to be clamped in without the heat-insulating component requiring a heat-resistant body to protect it from pressure forces that occur.
- the invention provides a cylinder head of a piston engine with a heat-insulating component made of sintered aluminum titanate, which has openings for valves, spark plugs or injection nozzles, which is characterized in that as a heat-insulating component one clamped in a flat and in the cylinder head or shrunk circular ring made of zirconium oxide shrunk circular plate made of aluminum titanate forms the largest part of the cylinder head base.
- the present invention makes it possible, due to the high strength of the zirconium oxide, to clamp the heat-insulating component made of circular aluminum titanate plate and zirconium oxide annulus in the cylinder head, wherein a cylinder head gasket made of steel, which is known per se, can be used for sealing between the component and the engine block.
- the heat-insulating component can be fixed in the cylinder head by Passitz or by a temporary adhesive connection.
- fastening by means of a shrink fit is preferred, an assembly method consisting in cooling and fitting the component.
- the entire cylinder head can also be heated, whereupon the component is inserted and the cylinder head is allowed to cool.
- the advantage of the present invention is that the arrangement of a circular plate made of aluminum titanate in a circular ring made of zirconium oxide enables such a component to be clamped in the cylinder head without the risk of destruction due to the low strength of the aluminum titanate plate.
- a further advantage is that the heat-insulating component according to the invention, due to the low thermal conductivity of zirconium oxide, which is comparable with aluminum titanate, allows the entire surface of the cylinder head opposite the combustion chamber to be formed from insulating material.
- the present invention avoids the formation of thermal bridges, since it is possible due to the high strength of the zirconium oxide to carry out the sealing against the combustion chamber on the circular ring made of zirconium oxide.
- the advantage of the present invention is that a multi-layer and complicated structure of the insulating layer is eliminated and it is also possible to provide separate openings for valve seats, spark plugs and injection nozzles in the heat-insulating component.
- the valve seats can be made of steel, but because of their high wear resistance, the formation of valve seats made of zirconium oxide is preferred.
- the annulus consists of partially stabilized zirconium oxide.
- Partially stabilized zirconium oxide (PSZ) in the context of the present invention means a zirconium oxide partly stabilized with the oxides of calcium, magnesium and yttrium, in which the cubic phase does not exceed 80% by weight of the zirconium oxide fraction.
- the grain size of the zirconium oxide in the finished sintered annulus is on average 5o ⁇ m.
- the partially stabilized zirconium oxide has a proportion of the tetragonal modification between 2o and 60% by weight and a monoclinic proportion of not> 6% by weight, the proportion of the cubic modification being in any case not more than 80% by weight and the proportions of the individual modifications add up to 100% by weight.
- the flexural strength 6 B of the partially stabilized zirconium oxide is preferably at least 400 MPa and the porosity is ⁇ 3%.
- an embodiment has proven to be particularly suitable in which the circular plate and annulus forming the heat-insulating component are flat and have the same thickness.
- the circular plate 2 and Circular ring 12 existing component forms the largest part of the cylinder head base 9, so that only collar 6, in which the circular ring 12 is clamped, forms a non-insulating part of the cylinder head base 9, but which is outside the combustion chamber lo.
- a valve seat 3 embedded in the circular plate 2 consists of partially stabilized zirconium oxide (PSZ).
- a bore 4 serves to receive an injection nozzle, not shown.
- cooling water channels 7 are formed, an exhaust valve 5 is also shown, as well as 8 designated cylinder head screws.
- the cylinder head 1 is sealed off from the combustion chamber 10 with a cylinder head gasket 15 between the annular ring 12 and the cylinder walls 13.
- FIG 2 the circular plate 2 shown in Figure 1 made of aluminum titanate, which is shrunk into a circular ring 12 made of partially stabilized zirconium oxide, is shown in the bottom view.
- the circular plate 2 made of aluminum titanate bores 11 and 14 are used for inserting the valve seats 3 for intake and exhaust valves.
- Valve seats 3 made of partially stabilized zirconium oxide are embedded in the bores 11, 14.
- the bore 4 serves to insert an injection nozzle.
- Arrows A, A ' indicate the area of the circular plate which is normally particularly at risk from thermally induced voltages, but in which, according to the present invention, the thermally induced voltage is outside the critical area.
- valve seats with a height which is greater than that Thickness of the circular plate so that the valve seats can be shrunk into corresponding recesses in the cylinder head.
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Cylinder Crankcases Of Internal Combustion Engines (AREA)
Abstract
Bei einem Zylinderkopf (1) eines Kolbenmotors besteht ein wärmeisolierendes Bauteil mit Öffnungen zur Aufnahme von Ventilsitzen, Zündkerzen, Einspritzdüsen aus einer kreisförmigen Aluminiumtitanatplatte (2), die in einen flachen und im Zylinderkopf (1) eingespannten oder eingeschrumpften Kreisring (12) aus Zirkonoxid eingeschrumpft ist. Die kreisförmige Platte (2) aus Aluminiumtitanat bildet den größten Teil des Zylinderkopfbodens (9).In the case of a cylinder head (1) of a piston engine, a heat-insulating component with openings for receiving valve seats, spark plugs and injection nozzles consists of a circular aluminum titanate plate (2) which is shrunk into a flat circular ring (12) made of zirconium oxide which is clamped or shrunk in the cylinder head (1) is. The circular plate (2) made of aluminum titanate forms the largest part of the cylinder head base (9).
Description
Die vorliegende Erfindung betrifft den Zylinderkopf eines Kolbenmotors mit einem durch Sintern hergestellten wärmeisolierenden Bauteil aus Aluminiumtitanat, das Öffnungen für Ventile, Zündkerzen oder Einspritzdüsen aufweist.The present invention relates to the cylinder head of a piston engine with a heat-insulating component made of aluminum titanate, which is produced by sintering and has openings for valves, spark plugs or injection nozzles.
Zur Vermeidung von Wändungsverlusten wurde in der DE-OS 28 21 506 bereits vorgeschlagen, die Innenfläche eines Zylinderkopfes durch eine Verbundisolierplatte abzudecken. Die beschriebene Verbundisolierplatte besteht aus einer eigentlichen Isolierschicht und aus einer mit ihr fest verbundenen metallischen Stützplatte. Die Isolierschicht ist dem Brennraum zugewandt und besteht entweder aus Quarzglas, Siliziumnitrid bzw. Siliziumcarbid und ist entweder auf die metallische Stützplatte aufgeschmolzen oder aufgesintert oder die Isolierschicht besitzt einen mehrlagigen Aufbau mit einer besonders porösen Zwischenschicht, die vorzugsweise aus Kügelchen des Isolierstoffes gebildet wird. Nachteilig bei einem solchen Zylinderkopf ist, daß die übliche Anordnung von mehreren separaten öffnungen für Ventile, Zündkerzen und Einspritzdüsen schwierig ist und infolgedessen eine einzige öffnung in der Verbundisolierplatte vorgesehen werden muß. Ein weiterer Nachteil liegt in dem komplizierten Aufbau, insbesondere darin, daß die eigentliche Isolierschicht infolge ihrer geringen Festigkeit eine metallische Stützplatte benötigt.In order to avoid wall losses, DE-OS 28 21 506 has already proposed covering the inner surface of a cylinder head with a composite insulating plate. The composite insulating plate described consists of an actual insulating layer and a metallic support plate firmly connected to it. The insulating layer faces the combustion chamber and consists either of quartz glass, silicon nitride or silicon carbide and is either melted or sintered onto the metallic support plate or the insulating layer has a multilayer structure with a particularly porous intermediate layer, which is preferably formed from beads of the insulating material. A disadvantage of such a cylinder head is that the usual arrangement of a plurality of separate openings for valves, spark plugs and injection nozzles is difficult and, as a result, a single opening must be provided in the composite insulating plate. Another disadvantage lies in the complicated structure, in particular in the fact that the actual insulating layer is metallic due to its low strength Support plate needed.
Durch die DE-OS 30 39 718 wurde ein Zylinderkopf bekannt, in dem ein aus Siliziumnitrid bestehender warmfester Körper in ein aus Aluminiumtitanat bestehendes wärmeisolierendes Bauteil eingesetzt und dieses Verbundteil in einen metallischen Stützkörper, der ggf. vom Zylinderkopf gebildet wird, eingeschrumpft ist. Der den Boden des Zylinderkopfes bildende warmfeste Körper ist dem Brennraum zugewandt und schützt das wärmeisolierende Bauteil vor mechanischer Beanspruchung. Das wärmeisolierende Bauteil hat die Form einer Kreisscheibe mit einem randseitig angebrachten Kragen zur Aufnahme des warmfesten Körpers. Nachteilig ist auch hier der mehrlagige Aufbau der aus unterschiedlichen Werkstoffen bestehenden einzelnen Bauteile, der sich aus der geringen Festigkeit des Aluminiumtitanates erklärt. Ein weiterer Nachteil besteht darin, daß das aus wärmeisolierendem Bauteil und warmfestem Körper bestehende Verbundteil im Zylinderkopf zusätzlichen Platz beansprucht und dadurch die komplizierten Ausbildungen der Kühlwasserkanäle beeinträchtigt. Ein weiterer Nachteil ergibt sich daraus, daß eine Abdichtung des Zylinderkopfes gegen die Zylinderlaufbüchse infolge der geringen Festigkeit des Aluminiumtitanats nicht im Bereich des Aluminiumtitanat-Bauteils vorgenommen werden kann, so daß die Abdichtung auf dem gut wärmeleitenden warmfesten Körper mit dem Nachteil einer Wärmebrückenbildung erfolgt. Eine Abdichtung außerhalb des Verbund-Bauteils aus Aluminiumtitanat ist nicht möglich, weil aus Konstruktionsgründen die Ventilbohrungen bis an den Rand des Bauteils zu führen sind. Da Aluminiumtitanat einen niedrigen E-Modul hat, ist es notwendig, den Zylinderkopf zum Einschrumpfen des Verbundteils relativ hoch zu erhitzen, was als weiterer Nachteil zu gelten hat.From DE-OS 30 39 718 a cylinder head has been known in which a heat-resistant body made of silicon nitride is inserted into a heat-insulating component made of aluminum titanate and this composite part is shrunk into a metallic support body which may be formed by the cylinder head. The heat-resistant body forming the bottom of the cylinder head faces the combustion chamber and protects the heat-insulating component from mechanical stress. The heat-insulating component has the shape of a circular disk with a collar attached on the edge to accommodate the heat-resistant body. The multilayer structure of the individual components made of different materials is also disadvantageous here, which is explained by the low strength of the aluminum titanate. Another disadvantage is that the composite part consisting of a heat-insulating component and a heat-resistant body takes up additional space in the cylinder head and thereby impairs the complicated designs of the cooling water ducts. Another disadvantage arises from the fact that the cylinder head cannot be sealed against the cylinder liner due to the low strength of the aluminum titanate in the area of the aluminum titanate component, so that the seal is made on the heat-conducting body with good thermal conductivity with the disadvantage of forming a thermal bridge. A seal outside of the composite component Aluminum titanate is not possible because, for design reasons, the valve holes have to be led to the edge of the component. Since aluminum titanate has a low modulus of elasticity, it is necessary to heat the cylinder head relatively high to shrink the composite part, which has to be considered a further disadvantage.
Aufgabe der vorliegenden Erfindung ist es, die bestehenden Nachteile zu überwinden und zur Erzielung einer befriedigenden Isolierwirkung im Zylinderkopf ein wärmeisolierendes Bauteil zur Verfügung zu stellen, das in den Zylinderkopf eingesetzt werden kann, ohne daß Wärmebrücken zum Zylinderkopf oder Motorblock entstehen,und das ferner über einen einfachen Aufbau und eine geringe Bauhöhe verfügt, so daß die Ausbildung von Kühlwasserkanälen zumindest in diesem kritischen, dem Brennraum benachbarten Bereich, nicht behindert wird.'Weiterhin soll das wärmeisolierende Bauteil eine ausreichende Festigkeit gegenüber mechanischen Kräften, insbesondere Druckkräften aufweisen.The object of the present invention is to overcome the existing disadvantages and to provide a satisfactory insulating effect in the cylinder head to provide a heat-insulating component that can be used in the cylinder head without thermal bridges to the cylinder head or engine block, and also via one has a simple structure and a low overall height, so that the formation of cooling water channels is not impeded, at least in this critical area adjacent to the combustion chamber. 'Further to the heat insulating member having a sufficient resistance to mechanical forces, in particular compression forces.
Eine weitere Aufgabe sieht die Erfindung darin, für einen festen Sitz des Bauteils im Zylinderkopf zu sorgen und gleichzeitig eine einfache Montagemöglichkeit für das wärmeisolierende Bauteil zu entwickeln. Insbesondere will die Erfindung eine Möglichkeit schaffen, die das Einspannen des wärmeisolierenden Bauteils ermöglicht, ohne daß das wärmeisolierende Bauteil zum Schutz vor auftretenden Druckkräften einen warmfesten Körper benötigt.Another object of the invention is to ensure that the component is firmly seated in the cylinder head and at the same time to develop a simple mounting option for the heat-insulating component. In particular, the invention seeks to create a possibility that enables the heat-insulating component to be clamped in without the heat-insulating component requiring a heat-resistant body to protect it from pressure forces that occur.
Zur Lösung dieser Aufgabe sieht die Erfindung einen Zylinderkopf eines Kolbenmotors mit einem durch Sintern hergestellten wärmeisolierenden Bauteil aus Aluminiumtitanat, das Öffnungen für Ventile, Zündkerzen oder Einspritzdüsen aufweist, vor, der dadurch gekennzeichnet ist, daß als wärmeisolierendes Bauteil eine in einen flachen und im Zylinderkopf eingespannten oder eingeschrumpften Kreisring aus Zirkonoxid eingeschrumpfte kreisförmige Platte aus Aluminiumtitanat den größten Teil des Zylinderkopfbodens bildet.To achieve this object, the invention provides a cylinder head of a piston engine with a heat-insulating component made of sintered aluminum titanate, which has openings for valves, spark plugs or injection nozzles, which is characterized in that as a heat-insulating component one clamped in a flat and in the cylinder head or shrunk circular ring made of zirconium oxide shrunk circular plate made of aluminum titanate forms the largest part of the cylinder head base.
Die vorliegende Erfindung ermöglicht es, infolge der hohen Festigkeit des Zirkonoxids das wärmeisolierende Bauteil aus kreisförmiger Aluminiumtitanatplatte und Zirkonoxid-Kreisring in den Zylinderkopf einzuspannen, wobei zur Abdichtung zwischen Bauteil und Motorblock eine an sich bekannte Zylinderkopfdichtung aus Stahl Verwendung finden kann. Zur Montage des Zylinderkopfes kann das wärmeisolierende Bauteil durch Passitz oder durch eine temporäre Klebeverbindung im Zylinderkopf fixiert sein. Bevorzugt wird aber eine Befestigung durch Schrumpfsitz, wobei ein Montageverfahren darin besteht, das Bauteil abzukühlen und einzupassen. In bevorzugtem Montageverfahren kann aber auch der gesamte Zylinderkopf erhitzt werden, worauf das Bauteil eingefügt wird und man den Zylinderkopf erkalten läßt.The present invention makes it possible, due to the high strength of the zirconium oxide, to clamp the heat-insulating component made of circular aluminum titanate plate and zirconium oxide annulus in the cylinder head, wherein a cylinder head gasket made of steel, which is known per se, can be used for sealing between the component and the engine block. To assemble the cylinder head, the heat-insulating component can be fixed in the cylinder head by Passitz or by a temporary adhesive connection. However, fastening by means of a shrink fit is preferred, an assembly method consisting in cooling and fitting the component. In a preferred assembly process, however, the entire cylinder head can also be heated, whereupon the component is inserted and the cylinder head is allowed to cool.
Der Vorteil der vorliegenden Erfindung besteht darin, daß die Anordnung einer kreisförmigen Platte aus Aluminiumtitanat in einem Kreisring aus Zirkonoxid die Einspannung eines solchen Bauteils im Zylinderkopf ermöglicht, ohne daß infolge der geringen Festigkeit der Aluminiumtitanatplatte die Gefahr der Zerstörung besteht. Ein weiterer Vorteil liegt darin, daß das erfindungsgemäße wärmeisolierende Bauteil es infolge der geringen und mit Aluminiumtitanat vergleichbaren Wärmeleitfähigkeit des Zirkonoxids erlaubt, die gesamte dem Brennraum gegenüberliegende Fläche des Zylinderkopfes aus isolierendem Werkstoff zu bilden. Gegenüber dem aus der DE-OS 30 39 718 bekannten Zylinderkopf vermeidet die vorliegende Erfindung die Ausbildung von Wärmebrücken, da es durch die hohe Festigkeit des Zirkonoxids möglich ist, die Abdichtung gegenüber dem Brennraum auf dem Kreisring aus Zirkonoxid durchzuführen. Gegenüber der DE-OS 28 21 506 besteht der Vorteil der vorliegenden Erfindung darin, daß ein mehrschichtiger und komplizierter Aufbau der Isolierschicht entfällt und es außerdem möglich ist, separate Öffnungen für Ventilsitze, Zündkerzen und Einspritzdüsen in dem wärmeisolierenden Bauteil vorzusehen. Die Ventilsitze können aus Stahl hergestellt sein, wegen seiner hohen Verschleißfestigkeit ist jedoch die Ausbildung von Ventilsitzen aus Zirkonoxid bevorzugt.The advantage of the present invention is that the arrangement of a circular plate made of aluminum titanate in a circular ring made of zirconium oxide enables such a component to be clamped in the cylinder head without the risk of destruction due to the low strength of the aluminum titanate plate. A further advantage is that the heat-insulating component according to the invention, due to the low thermal conductivity of zirconium oxide, which is comparable with aluminum titanate, allows the entire surface of the cylinder head opposite the combustion chamber to be formed from insulating material. Compared to the cylinder head known from DE-OS 30 39 718, the present invention avoids the formation of thermal bridges, since it is possible due to the high strength of the zirconium oxide to carry out the sealing against the combustion chamber on the circular ring made of zirconium oxide. Compared to DE-OS 28 21 506, the advantage of the present invention is that a multi-layer and complicated structure of the insulating layer is eliminated and it is also possible to provide separate openings for valve seats, spark plugs and injection nozzles in the heat-insulating component. The valve seats can be made of steel, but because of their high wear resistance, the formation of valve seats made of zirconium oxide is preferred.
In einer ganz besonders bevorzugten Ausführungsform der vorliegenden Erfindung besteht der Kreisring aus teilstabilisiertem Zirkonoxid. Unter teilstabilisiertem Zirkonoxid (PSZ) wird im Rahmen der vorliegenden Erfindung ein mit den Oxiden des Kalziums, Magnesiums und Yttriums teilstabilisiertes Zirkonoxid verstanden, bei dem die kubische Phase 8o Gew.% des Zirkonoxidanteils nicht überschreitet. Die Korngröße des Zirkonoxids liegt im fertig gesinterten Kreisring bei durchschnittlich 5o µm.In a very particularly preferred embodiment of the present invention, the annulus consists of partially stabilized zirconium oxide. Partially stabilized zirconium oxide (PSZ) in the context of the present invention means a zirconium oxide partly stabilized with the oxides of calcium, magnesium and yttrium, in which the cubic phase does not exceed 80% by weight of the zirconium oxide fraction. The grain size of the zirconium oxide in the finished sintered annulus is on average 5o µm.
Gemäß weiteren bevorzugten Ausführungsformen weist das teilstabilisierte Zirkonoxid einen Anteil der tetragonalen Modifikation zwischen 2o und 6o Gew.% und einen monoklinen Anteil von nicht > 6 Gew.% auf, wobei in jedem Fall der Anteil der kubischen Modifikation nicht mehr als 80 Gew.% beträgt und die Anteile der einzelnen Modifikationen sich auf loo Gew.% ergänzen. Die Biegebruchfestigkeit 6 B des teilstabilisierten Zirkonoxids beträgt vorzugsweise mindestens 4oo MPa und die Porosität liegt bei <3%.According to further preferred embodiments, the partially stabilized zirconium oxide has a proportion of the tetragonal modification between 2o and 60% by weight and a monoclinic proportion of not> 6% by weight, the proportion of the cubic modification being in any case not more than 80% by weight and the proportions of the individual modifications add up to 100% by weight. The flexural strength 6 B of the partially stabilized zirconium oxide is preferably at least 400 MPa and the porosity is <3%.
In konstruktiver Hinsicht hat sich eine Ausführungsform als besonders geeignet erwiesen, bei dem die das wärmeisolierende Bauteil bildende kreisförmige Platte und Kreisring plan sind und gleiche Dicke aufweisen.In terms of design, an embodiment has proven to be particularly suitable in which the circular plate and annulus forming the heat-insulating component are flat and have the same thickness.
Die hervorragende Eignung des erfindungsgemäßen Zylinderkopfes mit einer kreisförmigen,von einem Kreisring aus Zirkonoxid eingefaßten Aluminiumtitanatplatte erklärt sich wie folgt:
- Die höchsten Temperaturen entstehen in dem den Bohrungen benachbarten Bereich, insbesondere in dem durch die Bohrungen für das Aus- und Einlaßventil gebildeten Zwickel. Der äußere Bereich der kreisförmigen Platte ist dagegen durch den Kontakt mit der Dichtung bzw. mit dem gekühlten Motorblock grundsätzlich weniger temperaturbeansprucht. Durch den Kunstgriff, die Kreisplatte aus einem gut isolierenden Material geringer linearer thermischer Ausdehnung, nämlich aus Aluminiumtitanat herzustellen, sind die auf den Kreisring thermisch induzierten Spannungen so gering, daß sie in keinem Fall zu einer Rißbildung in diesem aus Zirkonoxid bestehenden Bauteil führen, obwohl die thermische Ausdehnung von Zirkonoxid um mehr als das Dreifache höher liegt als die von Aluminiumtitanat. Infolge der geringen Wärmeleitfähigkeit des Zirkonoxids tritt aber trotzdem kein Verlust an Isolierwirkung ein.
- The highest temperatures arise in the area adjacent to the holes, in particular in the area through the holes for the exhaust and inlet valve formed gusset. The outer area of the circular plate, on the other hand, is generally less exposed to high temperatures due to contact with the seal or with the cooled engine block. The trick of making the circular plate from a well insulating material of low linear thermal expansion, namely from aluminum titanate, the stresses thermally induced on the circular ring are so low that they in no case lead to cracking in this zirconium oxide component, although the The thermal expansion of zirconium oxide is more than three times higher than that of aluminum titanate. However, due to the low thermal conductivity of the zirconium oxide, there is no loss of insulation.
Die nachfolgenden Figuren dienen der näheren Erläuterung der Erfindung, ohne daß die Erfindung auf die gezeigten Ausführungsformen beschränkt ist. Es zeigen:
- Fig. 1 einen Längsschnitt durch ein Ausführungsbeispiel eines erfindungsgemäßen Zylinderkopfes, entsprechend Linie I-I der Fig. 2;
- Fig. 2 die Untersicht unter die in Fig. 1 als wärmeisolierendes Bauteil gezeigte kreisförmige Platte aus Aluminiumtitanat, die in einen Kreisring aus teilstabilisiertem Zirkonoxid eingeschrumpft ist.
- 1 shows a longitudinal section through an embodiment of a cylinder head according to the invention, corresponding to line II of Fig. 2.
- Fig. 2 is the bottom view of the circular plate made of aluminum titanate shown in Fig. 1 as a heat insulating component, which is shrunk into an annulus made of partially stabilized zirconium oxide.
In den in Fig. 1 gezeigten Zylinderkopf 1 ist als wärmeisolierendes Bauteil eine kreisförmige Platte 2 aus Aluminiumtitanat, die in einen Kreisring 12 aus teilstabilisiertem Zirkonoxid eingeschrumpft ist, eingespannt. Das aus kreisförmiger Platte 2 und Kreisring 12 bestehende Bauteil bildet den größten Teil des Zylinderkopfbodens 9, so daß lediglich Kragen 6, in den der Kreisring 12 eingespannt ist, einen nicht isolierenden Bestandteil des Zylinderkopfbodens 9 bildet, der aber außerhalb des Brennraumes lo liegt. Ein in die kreisförmige Platte 2 eingelassener Ventilsitz 3 besteht aus teilstabilisiertem Zirkonoxid (PSZ). Eine Bohrung 4 dient zur Aufnahme einer nicht gezeigten Einspritzdüse. Im Zylinderkopf 1 sind Kühlwasserkanäle 7 ausgebildet, ferner ist ein Auslaßventil 5 gezeigt, sowie mit 8 bezeichnete Zylinderkopfschrauben. Die Abdichtung von Zylinderkopf 1 gegen den Brennraum lo erfolgt mit einer Zylinderkopfdichtung 15 zwischen Kreisring 12 und Zylinderwänden 13.In the cylinder head 1 shown in FIG. 1, a
In Figur 2 ist die in Figur 1 gezeigte kreisförmige Platte 2 aus Aluminiumtitanat, die in einen Kreisring 12 aus teilstabilisiertem Zirkonoxid eingeschrumpft ist, in der Untersicht dargestellt. In der kreisförmigen Platte 2 aus Aluminiumtitanat dienen Bohrungen 11 und 14 zum Einsetzen der Ventilsitze 3 für Ein- und Auslaßventile. Ventilsitze 3 aus teilstabilisiertem Zirkonoxid sind in die Bohrungen 11, 14 eingelassen. Die Bohrung 4 dient, wie oben erwähnt, zum Einsetzen einer Einspritzdüse. Pfeile A, A' geben den Bereich der kreisförmigen Platte an, der normalerweise durch thermisch induzierte Spannungen besonders gefährdet ist, bei dem gemäß der vorliegenden Erfindung die thermisch induzierte Spannung aber außerhalb des kritischen Bereiches liegt.In Figure 2, the
Eine in den vorstehenden Figuren nicht gezeigte bevorzugte Möglichkeit besteht in der Ausbildung von Ventilsitzen mit einer Höhe, die größer ist als die Dicke der kreisförmigen Platte, so daß die Ventilsitze in entsprechenden Ausnehmungen des Zylinderkopfes eingeschrumpft werden können.A preferred possibility, not shown in the preceding figures, consists in the formation of valve seats with a height which is greater than that Thickness of the circular plate so that the valve seats can be shrunk into corresponding recesses in the cylinder head.
Claims (6)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE3307114 | 1983-03-01 | ||
DE3307114A DE3307114C2 (en) | 1983-03-01 | 1983-03-01 | Cylinder head of a piston engine |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0120222A2 true EP0120222A2 (en) | 1984-10-03 |
EP0120222A3 EP0120222A3 (en) | 1986-08-06 |
Family
ID=6192149
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP84100984A Ceased EP0120222A3 (en) | 1983-03-01 | 1984-02-01 | Heat-insulated bottom of a cylinder head of a piston engine |
Country Status (5)
Country | Link |
---|---|
US (1) | US4524732A (en) |
EP (1) | EP0120222A3 (en) |
JP (1) | JPS59162345A (en) |
DE (1) | DE3307114C2 (en) |
ES (1) | ES286126Y (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0277548A1 (en) * | 1987-01-28 | 1988-08-10 | John Deere Technologies International Inc. | Rotating piston engine |
EP0287236A2 (en) * | 1987-04-11 | 1988-10-19 | Isuzu Motors Limited | Heat-insulating engine structure and method of manufacturing the same |
Families Citing this family (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3335536A1 (en) * | 1983-09-30 | 1985-04-18 | Dr.Ing.H.C. F. Porsche Ag, 7000 Stuttgart | DEVICE FOR LIMITING RADIAL THERMAL EXPANSIONS OF CYLINDERS OF A PISTON PISTON COMBUSTION ENGINE |
DE3634588A1 (en) * | 1986-10-10 | 1988-04-21 | Feldmuehle Ag | SINTER MOLDED BODY |
JPS61237867A (en) * | 1985-04-15 | 1986-10-23 | Kawasaki Heavy Ind Ltd | Cylinder head for internal-combustion engine |
DE3523131C1 (en) * | 1985-06-28 | 1986-10-23 | Feldmühle AG, 4000 Düsseldorf | Cylinder head plate for a piston engine |
DE3726027A1 (en) * | 1987-08-05 | 1989-02-16 | Alcan Gmbh | HEAT-INPUTED COMPONENT |
US5139979A (en) * | 1989-01-30 | 1992-08-18 | Lanxide Technology Company, Lp | Method of producing self-supporting aluminum titanate composites and products relating thereto |
US5667898A (en) * | 1989-01-30 | 1997-09-16 | Lanxide Technology Company, Lp | Self-supporting aluminum titanate composites and products relating thereto |
US5340783A (en) * | 1989-01-30 | 1994-08-23 | Lanxide Technology Company, Lp | Method of producing self-supporting aluminum titanate composites and products relating thereto |
US4955337A (en) * | 1989-12-18 | 1990-09-11 | Cummins Engine Company, Inc. | High compression internal combustion engine |
US5295462A (en) * | 1992-10-16 | 1994-03-22 | Cummins Engine Co., Inc. | Coin insert for the firing deck in an internal combustion engine |
US5598820A (en) * | 1995-05-09 | 1997-02-04 | Edelbrock Corporation | Cylinder head for four stroke internal combustion engine |
EP0752527B1 (en) * | 1995-07-06 | 2000-02-02 | Isuzu Ceramics Research Institute Co., Ltd. | Engine having sound absorption structures on the outer sides of combustion chambers |
US5630389A (en) * | 1995-09-29 | 1997-05-20 | Self; Kevin G. | Cylinder head bolt plug |
AUPP581098A0 (en) * | 1998-09-11 | 1998-10-01 | Ecotrans Pty. Limited | Engine conversions |
AT5142U1 (en) * | 2000-12-18 | 2002-03-25 | Avl List Gmbh | Internal combustion engine |
DE102005037735B4 (en) * | 2005-08-05 | 2010-07-01 | Nemak Linz Gmbh | Cylinder head casting blank, cast cylinder head for diesel internal combustion engines and method of making a cylinder head casting blank |
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DE2821506A1 (en) * | 1978-05-17 | 1979-11-22 | Rudolf Dr Wieser | Piston and cylinder for IC engine - have heat resisting protective linings to make higher temps. possible |
GB2061383A (en) * | 1979-10-22 | 1981-05-13 | Saab Scania Ab | Piston engine or parts thereof having combustion chamber heat insulation |
EP0036786A1 (en) * | 1980-03-26 | 1981-09-30 | Ngk Insulators, Ltd. | Zirconia ceramics and a method of producing the same |
US4328772A (en) * | 1980-01-14 | 1982-05-11 | Cummins Engine Company, Inc. | Combustion chamber for an internal combustion engine |
EP0066022A1 (en) * | 1981-05-21 | 1982-12-08 | Ngk Insulators, Ltd. | Engine parts |
EP0067327A1 (en) * | 1981-05-27 | 1982-12-22 | Kabushiki Kaisha Toshiba | Ceramic engine part with improved abrasion resistance |
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FR570238A (en) * | 1922-08-30 | 1924-04-25 | Construction of pistons for combustion machines | |
DE615602C (en) * | 1932-09-30 | 1935-07-08 | Anton Broehl | Air-compressing, low-pressure internal combustion engine |
US3911891A (en) * | 1973-08-13 | 1975-10-14 | Robert D Dowell | Coating for metal surfaces and method for application |
US4398527A (en) * | 1980-08-22 | 1983-08-16 | Chevron Research Company | Internal combustion engine having manifold and combustion surfaces coated with a foam |
-
1983
- 1983-03-01 DE DE3307114A patent/DE3307114C2/en not_active Expired
-
1984
- 1984-02-01 EP EP84100984A patent/EP0120222A3/en not_active Ceased
- 1984-02-27 JP JP59034508A patent/JPS59162345A/en active Pending
- 1984-02-29 ES ES1984286126U patent/ES286126Y/en not_active Expired
- 1984-03-01 US US06/585,173 patent/US4524732A/en not_active Expired - Fee Related
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
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DE2821506A1 (en) * | 1978-05-17 | 1979-11-22 | Rudolf Dr Wieser | Piston and cylinder for IC engine - have heat resisting protective linings to make higher temps. possible |
GB2061383A (en) * | 1979-10-22 | 1981-05-13 | Saab Scania Ab | Piston engine or parts thereof having combustion chamber heat insulation |
US4328772A (en) * | 1980-01-14 | 1982-05-11 | Cummins Engine Company, Inc. | Combustion chamber for an internal combustion engine |
EP0036786A1 (en) * | 1980-03-26 | 1981-09-30 | Ngk Insulators, Ltd. | Zirconia ceramics and a method of producing the same |
EP0066022A1 (en) * | 1981-05-21 | 1982-12-08 | Ngk Insulators, Ltd. | Engine parts |
EP0067327A1 (en) * | 1981-05-27 | 1982-12-22 | Kabushiki Kaisha Toshiba | Ceramic engine part with improved abrasion resistance |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
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EP0277548A1 (en) * | 1987-01-28 | 1988-08-10 | John Deere Technologies International Inc. | Rotating piston engine |
EP0287236A2 (en) * | 1987-04-11 | 1988-10-19 | Isuzu Motors Limited | Heat-insulating engine structure and method of manufacturing the same |
EP0287236A3 (en) * | 1987-04-11 | 1989-12-20 | Isuzu Motors Limited | Heat-insulating engine structure and method of manufacturing the same |
Also Published As
Publication number | Publication date |
---|---|
ES286126Y (en) | 1986-06-16 |
US4524732A (en) | 1985-06-25 |
JPS59162345A (en) | 1984-09-13 |
ES286126U (en) | 1985-12-01 |
DE3307114C2 (en) | 1985-09-05 |
DE3307114A1 (en) | 1984-09-06 |
EP0120222A3 (en) | 1986-08-06 |
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Inventor name: OLAPINSKI, HANS, DR. DIPL.-CHEM. Inventor name: FINGERLE, DIETER, DR. DIPL.-ING. Inventor name: DWORAK, ULF, DR. DIPL.-MINERALOGE Inventor name: PALM, BENGT N. J., DIPL.-ING. Inventor name: HAKULINEN, MARTTI J. A., DIPL.-ING. Inventor name: KROHN, ULRICH, DR. DIPL.-ING. |