EP0285205A1 - Liquid-cooled piston - Google Patents

Liquid-cooled piston Download PDF

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Publication number
EP0285205A1
EP0285205A1 EP88200507A EP88200507A EP0285205A1 EP 0285205 A1 EP0285205 A1 EP 0285205A1 EP 88200507 A EP88200507 A EP 88200507A EP 88200507 A EP88200507 A EP 88200507A EP 0285205 A1 EP0285205 A1 EP 0285205A1
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EP
European Patent Office
Prior art keywords
piston
ring
empty groove
support
cooling chamber
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Granted
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EP88200507A
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German (de)
French (fr)
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EP0285205B1 (en
Inventor
Aktiengesellscha Kolbenschmidt
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Kolbenschmidt AG
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Kolbenschmidt AG
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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
    • F02F3/00—Pistons 
    • F02F3/0015—Multi-part pistons
    • F02F3/0023—Multi-part pistons the parts being bolted or screwed together
    • 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
    • F02F3/00—Pistons 
    • F02F3/16—Pistons  having cooling means
    • F02F3/20—Pistons  having cooling means the means being a fluid flowing through or along piston
    • F02F3/22—Pistons  having cooling means the means being a fluid flowing through or along piston the fluid being liquid
    • F02F3/225—Pistons  having cooling means the means being a fluid flowing through or along piston the fluid being liquid the liquid being directed into blind holes
    • 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
    • F02B3/00—Engines characterised by air compression and subsequent fuel addition
    • F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition
    • 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
    • F02F2200/00—Manufacturing
    • F02F2200/04—Forging of engine parts
    • 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
    • F05C2201/02—Light metals
    • F05C2201/021—Aluminium
    • 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
    • F05C2201/0433—Iron group; Ferrous alloys, e.g. steel
    • F05C2201/0448—Steel

Definitions

  • the invention relates to a piston with liquid cooling for internal combustion engines according to the preamble of claim 1.
  • two-part pistons consisting of a lower and upper part, which can be manufactured in different material combinations.
  • Cast or forged steel is a suitable material for the upper part, as is nodular cast iron with its strength values similar to those of steel.
  • the lower part can consist of a cast or forged aluminum piston alloy or also of gray cast iron. Both parts are preferably clamped together using expansion screws.
  • these pistons require cooling, preferably by means of a cooling oil.
  • signs of wear can be observed disadvantageously between the upper and lower parts of the pistons on the bearing surfaces of the support collars, which occur particularly in the outer region of the bearing surfaces and around the expansion screws.
  • This wear is caused by radial and axial movements of the bearing surfaces of the two piston components lying opposite one another in the connecting plane. These movements, which are caused by the carding effect caused by the deformation of the upper piston part as a result of temperature and gas pressure, not only produce wear, but also involve the risk of deformation of the lower piston part with subsequent crack formation and material abrasion.
  • different solutions are already provided, for example by DE-PS 27 58 378 and EP-PS 7661.
  • the transition area between the inner surface of the piston crown and that at an angle of 35 to 55 ° is preferred according to a special feature of the piston designed according to the invention 45 °, the inner surface of the support collar (9) of the upper part (5), which inclines outwards and slopes towards the parting plane, is rounded with a radius of 30 to 60 mm.
  • FIG. 1 shows a detail of the piston designed according to the invention along the planes including the piston axis and the pin axis direction on the one hand and the piston axis and the direction perpendicular to the pin axis direction on the other hand in an axionometric representation.
  • FIG. 2 shows a half of a section through the upper part of the piston along the plane comprising the piston axis and the pin axis direction.
  • the piston is made of a gray cast iron, the piston pin (1) receiving the lower part (2) and a steel, the central cooling chamber (3) delimiting and the ring section (4) supporting upper part (5) with a flat combustion chamber bowl (6) , which are clamped together via expansion screws, not shown.
  • the lower part (2) is set back on both sides of the horizontal plane enclosing the pin axis direction and on the piston foot side up to the lower end like a sinew against the outer circumference of the lower part (2) and the hubs (7) of the pin eyes are displaced towards the piston axis.
  • the lower part (2) and the upper part (5) are supported against one another by means of annular support surfaces (10, 11) which are mounted on support collars (8, 9) in their plane of separation perpendicular to the piston axis.
  • the expansion screws are led through the support collars (8,9) and the contact surfaces (10,11).
  • the ring section (4) has two ring grooves (15, 16) for compression rings and one ring groove (17) for an oil ring.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)

Abstract

1. Piston with liquid cooling for internal combustion engines, in particular for medium-fast runing diesel engines, consisting of a lower section (2) receiving the gudgeon pin (1) and an upper section (5) delimiting a central cooling chamber (3) and bearing the ring zone (4), which are supported on each other on circular bearing surfaces (10, 11) in their division plane perpendicular to the piston axis and located on concentric supporting collars (8, 9), are braced together by screws guided through the supporting collars and the bearing surfaces, have in the region of their division plane a circumanbient empty groove (13) made starting from the outer periphery and are centred relative to each other by a ring fit (12) made on the outer periphery of the bearing surface of the upper section and resting on the radial outside of the supporting collar of the bearing surface of the lower section, characterised in that the ring zone (5) has ring grooves (15, 16, 17) receiving two compression rings and an oil ring, the height of the top land (21) is 6 to 10% and the compression height is 65 to 90% of the piston diameter, an empty groove (14) extending behing the ring zone branches off from the empty groove (13), and from the cooling chamber (3) blind holes (22) which run into the middle section of the piston head parallel to the piston axis and from the periphery of the cooling chamber blind holes (20) which run radially outwards and are inclined ascending relative to the division plane extend into the regions between the top land and the edge of the piston head.

Description

Die Erfindung betrifft einen Kolben mit Flüssigkeitskühlung für Brennkraftmaschinen nach dem Oberbegriff des Patentanspruchs 1.The invention relates to a piston with liquid cooling for internal combustion engines according to the preamble of claim 1.

Für hohe und höchste Belastung ist ein Einsatz solch zweiteiliger aus Unter- und Oberteil bestehender Kolben unumgänglich, die in verschiedenen Werkstoffkombinationen herstellbar sind. Als Werkstoff für das Oberteil bietet sich gegossener oder geschmiedeter Stahl an, ebenso Sphäroguß mit seinen dem Stahl ähnlichen Festigkeitswerten. Das Unterteil kann aus einer gegossenen oder geschmiedeten Aluminium-Kolbenlegierung oder auch aus Grauguß bestehen. Beide Teile sind vorzugsweise über Dehnschrauben miteinander verspannt. Diese Kolben verlangen in aller Regel eine Kühlung, vorzugsweise mittels eines Kühlöls. Bei solchen zweiteiligen Kolben sind in nachteiliger Weise zwischen dem Kolbenober- und -unterteil an den Auflageflächen der Abstützbunde Verschleißerscheinungen zu beobachten, die insbesondere im Außenbereich der Auflageflächen und um die Dehnschrauben herum auftreten. Dieser Verschleiß wird durch radiale und axiale Bewegungen der in der Verbindungsebene gegeneinander liegenden Auflageflächen der beiden Kolbenbauteile verursacht. Diese Bewegungen, die durch den durch die Deformation des Kolbenoberteils infolge Temperatur und Gasdruck bewirkten Krempeleffekt hervorgerufen werden, erzeugen nicht nur einen Verschleiß, sondern beinhalten auch die Gefahr einer Deformation des Kolbenunterteils mit nachfolgender Rißbildung und Materialabscheuerung in sich. Zur Vermeidung dieser Nachteile sind bereits unterschiedliche Lösungen, z.B. durch die DE-PS 27 58 378 und die EP-PS 7661, vorgesehen.For high and highest loads, it is essential to use such two-part pistons, consisting of a lower and upper part, which can be manufactured in different material combinations. Cast or forged steel is a suitable material for the upper part, as is nodular cast iron with its strength values similar to those of steel. The lower part can consist of a cast or forged aluminum piston alloy or also of gray cast iron. Both parts are preferably clamped together using expansion screws. As a rule, these pistons require cooling, preferably by means of a cooling oil. In such two-part pistons, signs of wear can be observed disadvantageously between the upper and lower parts of the pistons on the bearing surfaces of the support collars, which occur particularly in the outer region of the bearing surfaces and around the expansion screws. This wear is caused by radial and axial movements of the bearing surfaces of the two piston components lying opposite one another in the connecting plane. These movements, which are caused by the carding effect caused by the deformation of the upper piston part as a result of temperature and gas pressure, not only produce wear, but also involve the risk of deformation of the lower piston part with subsequent crack formation and material abrasion. To avoid these disadvantages, different solutions are already provided, for example by DE-PS 27 58 378 and EP-PS 7661.

Für den Kolbenhersteller besteht die Aufgabe, den aus Ober- und Unterteil bestehenden Kolben nach dem Oberbegriff des Anspruchs 1 so zu gestalten, daß dieser der modernen Brennkraftmaschinentechnik angepaßt ist, wobei insbesondere eine Senkung des Gewichts und eine Verkleinerung der Bauhöhe der Bauteile anzustreben ist. Eine Gewichtsreduzierung darf dabei allerdings nicht zu Lasten der Betriebssicherheit und Lebensdauer gehen.For the piston manufacturer, there is the task of designing the piston consisting of the upper and lower part according to the preamble of claim 1 so that it is adapted to modern internal combustion engine technology, in particular a reduction in weight and a reduction in the overall height of the components. However, weight reduction must not be detrimental to operational safety and service life.

Gelöst ist diese Aufgabe durch die im kennzeichnenden Teil des Anspruchs 1 aufgeführten Merkmale.This object is achieved by the features listed in the characterizing part of claim 1.

Vorzugsweise Ausgestaltungsformen und Anordnungen der im Oberteil des Kolbens nach Anspruch 1 angeordneten Sacklochbohrungen sind im Hinblick auf eine optimierte Kühlwirkung in den Unteransprüchen 2 bis 4 wiedergegeben.Preferred embodiments and arrangements of the blind bores arranged in the upper part of the piston according to claim 1 are given in subclaims 2 to 4 with regard to an optimized cooling effect.

Um die an exponierten Stellen des Kolbenoberteils unter Temperatureinfluß entstehenden Spannungen und damit die Deformation so klein wie möglich zu halten, ist nach einem besonderen Merkmal des erfindungsgemäß gestalteten Kolbens der Übergangsbereich zwischen der Innenfläche des Kolbenbodens und der unter einem Winkel von 35 bis 55°, vorzugsweise 45°, zur Trennungsebene nach außen ansteigend geneigte Innenfläche des Abstützbundes (9) des Oberteils (5) mit einem Radius von 30 bis 60 mm verrundet.In order to keep the stresses that arise at exposed points of the upper piston part under the influence of temperature and thus the deformation as small as possible, the transition area between the inner surface of the piston crown and that at an angle of 35 to 55 °, is preferred according to a special feature of the piston designed according to the invention 45 °, the inner surface of the support collar (9) of the upper part (5), which inclines outwards and slopes towards the parting plane, is rounded with a radius of 30 to 60 mm.

In den Zeichnungen ist in Fig. 1 ein Ausschnitt des erfindungsgemäß ausgebildeten Kolbens entlang der die Kolbenachse und die Bolzenachsrichtung einerseits sowie die Kolbenachse und die Richtung senkrecht zur Bolzenachsrichtung einschließenden Ebenen andererseits in axionometrischer Darstellung wiedergegeben.1 shows a detail of the piston designed according to the invention along the planes including the piston axis and the pin axis direction on the one hand and the piston axis and the direction perpendicular to the pin axis direction on the other hand in an axionometric representation.

In Fig. 2 ist eine Hälfte eines Schnitts durch das Oberteil des Kolbens entlang der die Kolbenachse und die Bolzenachsrichtung umfassenden Ebene dargestellt.2 shows a half of a section through the upper part of the piston along the plane comprising the piston axis and the pin axis direction.

Der Kolben ist aus einem aus Grauguß bestehenden, den Kolbenbolzen (1) aufnehmenden Unterteil (2) und einem aus Stahl bestehenden, den zentralen Kühlraum (3) begrenzenden und die Ringpartie (4) tragenden Oberteil (5) mit flacher Brennraummulde (6) aufgebaut, die über nicht dargestellte Dehnschrauben miteinander verspannt sind. Das Unterteil (2) ist beidseitig der die Bolzenachsrichtung einschließenden horizontalen Ebene und kolbenfußseitig bis zum unteren Ende sehnenartig gegenüber dem Außenumfang des Unterteils (2) zurückgesetzt und die Naben (7) der Bolzenaugen zur Kolbenachse hin verschoben. Das Unterteil (2) und das Oberteil (5) stützen sich über in ihrer Trennungsebene senkrecht zur Kolbenachse stehenden auf Abstützbunden (8,9) angebrachten kreisringförmigen Auflageflächen (10,11) gegeneinander ab. Die Dehnschrauben sind durch die Abstützbunde (8,9) und die Auflageflächen (10,11) geführt. Am Außenumfang der Auflagefläche (11) des Oberteils (5) ist eine Ringpassung (12) angebracht, die an der Außenseite des Abstützbundes (8) der Auflagefläche (10) des Unterteils (2) zentrierend anliegt. Gegenüber der Trennungsebene von Oberteil (5) und Unterteil (2) befindet sich eine umlaufende Leernut (13) mit einem rechtwinklig davon abzweigenden parallel zur Kolbenachse verlaufenden sich hinter die Ringpartie (4) erstreckenden Abschnitt (14). Die Ringpartie (4) weist zwei Ringnuten (15,16) für Kompressionsringe und eine Ringnut (17) für einen Ölring auf. Vom Umfang des Kühlraums (3), der kolbenfußseitig durch einen gewölbeartig gestalteten und mit den Naben (7) verbundenen Boden (18) mit einer Ablauföffnung (19) für das Kühlöl abgeschlossen ist, erstrecken sich unter einem Winkel von 45° zur Trennungsebene ansteigend geneigte radial nach außen verlaufende Sacklochbohrungen (20) bis hinter den Feuersteg (21) und unter den Bereich des Randes des Kolbenbodens. Vom Kühlraum (3) ausgehend sind ferner koaxial verlaufende Sacklochbohrungen (22) im mittleren Teil des Kolbens in nicht dargestellter Sechseck-Konfiguration angebracht. Der Übergangsbereich (23) zwischen der Innenfläche des Kolbenbodens und der unter einem Winkel von 45° zur Trennungsebene ansteigend nach außen geneigten Innenfläche des Abstützbundes (9) des Oberteils (5) ist mit einem Radius von 40 mm verrundet.The piston is made of a gray cast iron, the piston pin (1) receiving the lower part (2) and a steel, the central cooling chamber (3) delimiting and the ring section (4) supporting upper part (5) with a flat combustion chamber bowl (6) , which are clamped together via expansion screws, not shown. The lower part (2) is set back on both sides of the horizontal plane enclosing the pin axis direction and on the piston foot side up to the lower end like a sinew against the outer circumference of the lower part (2) and the hubs (7) of the pin eyes are displaced towards the piston axis. The lower part (2) and the upper part (5) are supported against one another by means of annular support surfaces (10, 11) which are mounted on support collars (8, 9) in their plane of separation perpendicular to the piston axis. The expansion screws are led through the support collars (8,9) and the contact surfaces (10,11). On the outer circumference of the support surface (11) of the upper part (5) there is an annular fit (12) which is centered on the outside of the support collar (8) of the support surface (10) of the lower part (2). Opposite the plane of separation of the upper part (5) and lower part (2) there is a circumferential empty groove (13) with a section (14) which extends at right angles and runs parallel to the piston axis and extends behind the ring section (4). The ring section (4) has two ring grooves (15, 16) for compression rings and one ring groove (17) for an oil ring. From the circumference of the cooling chamber (3), which is on the piston foot side by a vault-like design and connected to the hubs (7) Bottom (18) is closed with a drain opening (19) for the cooling oil, extend at an angle of 45 ° to the plane of separation increasing inclined radially outwardly extending blind holes (20) behind the top land (21) and under the area of the edge of the Piston crown. Starting from the cooling chamber (3), coaxial blind bores (22) are also made in the central part of the piston in a hexagon configuration (not shown). The transition region (23) between the inner surface of the piston crown and the inner surface of the support collar (9) of the upper part (5), which inclines outward and rises at an angle of 45 ° to the separation plane, is rounded with a radius of 40 mm.

Die mit der Erfindung erzielten Vorteile bestehen insbesondere darin, daß durch eine vergleichsweise deutliche Verringerung cer Kompressionshöhe und damit der Bauhöhe des gebauten Kolbens eine erhebliche Gewichtsreduzierung erzielt wird. Diese Gewichtsreduzierung zeigt jedoch keine nachteiligen Wirkungen, da durch die Anordnung der Sacklochbohrungen eine optimale Kühlung von Kolbenboden und Ringpartie erzielt und andererseits die notwendige Elastizität bei guter Dauerfestigkeit durch die Anordnung und Ausgestaltung der Leernut im Bereich der Trennungsebene und des damit verbundenen kreisringförmigen und sich hinter die Ringpartie erstreckenden Abschnitts erreicht wird. Durch das Anbringen der Sacklochbohrungen wird eine vergleichsweise große Kühloberfläche erzeugt.The advantages achieved by the invention consist in particular in that a considerable reduction in weight is achieved by a comparatively significant reduction in the compression height and thus the overall height of the piston built. However, this weight reduction shows no adverse effects, since the arrangement of the blind holes achieves optimal cooling of the piston crown and ring section and, on the other hand, the necessary elasticity with good fatigue strength through the arrangement and design of the empty groove in the area of the parting plane and the associated circular and behind the Ring section extending section is reached. By making the blind holes, a comparatively large cooling surface is generated.

Claims (5)

1. Kolben mit Flüssigkeitskühlung für Brennkraftmaschinen, insbesondere für mittelschnellaufende Dieselmotoren, bestehend aus einem den Kolbenbolzen (1) aufnehmenden Unterteil (2) und einem einen zentralen Kühlraum (3) begrenzenden und das Ringfeld (4) tragenden Oberteil (5), die sich über in ihrer Trennungsebene senkrecht zur Kolbenachse liegende auf konzentrischen Abstützbunden (8,9) angeordnete kreisförmige Auflageflächen (10,11) gegeneinander abstützen, über durch die Abstützbunde und die Auflageflächen geführte Schrauben miteinander verspannt sind, im Bereich ihrer Trennungsebene eine vom Außenumfang her angebrachte umlaufende Leernut (13) aufweisen und durch eine an dem Außenumfang der Auflagefläche des Oberteils angebrachte an der radialen Außenseite des Abstützbundes der Auflagefläche des Unterteils anliegende Ringpassung (12) gegeneinander zentriert sind, dadurch gekennzeichnet, daß das Ringfeld (5) zwei Kompressionsringe und eine einen Ölring aufnehmende Ringnuten (15,16,17) aufweist, die Höhe des Feuerstegs (21) 6 bis 10 % und die Kompressionshöhe 65 bis 90 % des Kolbendurchmessers betragen, von der Leernut (13) eine sich hinter das Ringfeld erstreckende Leernut (14) abzweigt und sich vom Kühlraum (3) aus parallel zur Kolbenachse verlaufende Sacklochbohrungen (22) in den mittleren Teil des Kolbenbodens sowie vom Umfang des Kühlraums aus gegenüber der Trennungsebene ansteigend geneigte radial nach außen verlaufende Sacklochbohrungen (20) bis in die Bereiche hinter den Feuersteg und den Rand des Kolbenbodens erstrecken.1. Piston with liquid cooling for internal combustion engines, in particular for medium-speed diesel engines, consisting of a lower part (2) receiving the piston pin (1) and a central cooling chamber (3) delimiting and supporting the ring field (4), the upper part (5), which overlaps In their parting plane perpendicular to the piston axis, support circular contact surfaces (10, 11) arranged on concentric support collars (8, 9) against each other, by means of screws guided through the support collars and the contact surfaces, clamped together in the area of their parting plane, a circumferential empty groove attached from the outer circumference (13) and are centered against one another by a ring fit (12) attached to the outer circumference of the support surface of the upper part and resting on the radial outside of the support collar of the support surface of the lower part, characterized in that the ring field (5) has two compression rings and one oil ring Ring grooves (15,16,17) has, the height of the top land (21) 6 to 10% and the compression height 65 to 90% of the piston diameter, an empty groove (14) extending behind the ring field branches off from the empty groove (13) and parallel from the cooling chamber (3) Blind bore holes (22) running to the piston axis extend into the central part of the piston crown and, from the circumference of the cooling space, radially outwardly inclined blind bore holes (20) rising towards the separation plane extend into the areas behind the top land and the edge of the piston crown. 2. Kolben nach Anspruch 1, dadurch gekennzeichnet, daß der Durchmesser der Sacklochbohrungen (20,22) 10 bis 50 mm, vorzugsweise 20 bis 45 mm, beträgt.2. Piston according to claim 1, characterized in that the diameter of the blind bores (20, 22) is 10 to 50 mm, preferably 20 to 45 mm. 3. Kolben nach den Ansprüchen 1 und 2, dadurch gekennzeichnet, daß die vom Umfang des Kühlraums (3) ausgehenden gegenüber der Trennungsebene ansteigend geneigten Sacklochbohrungen (20) einen Winkel von 35 bis 55°, vorzugsweise 45°, mit der Trennungsebene bilden.3. Piston according to claims 1 and 2, characterized in that the outgoing from the periphery of the cooling space (3) with respect to the plane of separation inclined blind holes (20) form an angle of 35 to 55 °, preferably 45 °, with the plane of separation. 4. Kolben nach den Ansprüchen 1 bis 3, dadurch gekennzeichnet, daß die parallel zur Kolbenachse verlaufenden Sacklochbohrungen (22) auf den Ecken von gleichseitigen Sechsecken angeordnet sind.4. Piston according to claims 1 to 3, characterized in that the blind holes extending parallel to the piston axis (22) are arranged on the corners of equilateral hexagons. 5. Kolben nach den Ansprüchen 1 bis 4, dadurch gekennzeichnet, daß der Übergangsbereich zwischen der Innenfläche des Kolbenbodens und der unter einem Winkel von 35 bis 55°, vorzugsweise 45°, zur Trennungsebene nach außen ansteigend geneigte Innenfläche des Abstützbundes (9) des Oberteils (5) mit einem Radius von 30 bis 60 mm verrundet ist.5. Piston according to claims 1 to 4, characterized in that the transition region between the inner surface of the piston crown and the inner surface of the support collar (9) of the upper part, which rises outwardly at an angle of 35 to 55 °, preferably 45 ° (5) is rounded with a radius of 30 to 60 mm.
EP88200507A 1987-03-26 1988-03-18 Liquid-cooled piston Expired - Lifetime EP0285205B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3709969 1987-03-26
DE19873709969 DE3709969A1 (en) 1987-03-26 1987-03-26 PISTON WITH LIQUID COOLING

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Publication Number Publication Date
EP0285205A1 true EP0285205A1 (en) 1988-10-05
EP0285205B1 EP0285205B1 (en) 1990-10-03

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EP88200507A Expired - Lifetime EP0285205B1 (en) 1987-03-26 1988-03-18 Liquid-cooled piston

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DE (2) DE3709969A1 (en)
FI (1) FI880884A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0373689A1 (en) * 1988-12-16 1990-06-20 KOLBENSCHMIDT Aktiengesellschaft Oil-cooled piston for internal-combustion engines
EP0464626B1 (en) * 1990-06-29 1995-10-18 KOLBENSCHMIDT Aktiengesellschaft Assembled oil cooled piston for diesel engines
EP0520536B1 (en) * 1991-06-25 1997-04-09 KOLBENSCHMIDT Aktiengesellschaft Assembled, oil cooled piston for Diesel engines
US6539836B2 (en) * 2000-06-07 2003-04-01 Honda Giken Kogyo Kabushiki Kaisha Piston for internal combustion engine

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4007992A1 (en) * 1989-03-20 1990-09-27 Avl Verbrennungskraft Messtech Internal combustion engine piston - has separate top and bottom sections with chamber wall in bottom one
DE4010062A1 (en) * 1990-03-29 1991-10-02 Mahle Gmbh Oil cooling of piston - is for IC engine and involves annular groove in piston crown
DE4014703A1 (en) * 1990-05-08 1991-11-14 Mahle Gmbh COOLED SUBMERSIBLE PISTON FOR INTERNAL COMBUSTION ENGINES WITH SEPARATE PISTON TOP AND PISTON
DE10046420B4 (en) * 2000-09-20 2009-05-28 Mahle Gmbh Method of producing a bowl edge rounding
DE10244510A1 (en) * 2002-09-25 2004-04-08 Mahle Gmbh One-piece cooling channel piston for an internal combustion engine

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FR2317487A1 (en) * 1975-07-10 1977-02-04 Maschf Augsburg Nuernberg Ag DEVICE FOR COOLING, BY A LIQUID, OF WALLS SUBJECT TO THERMAL LOADS
US4286505A (en) * 1979-04-23 1981-09-01 Caterpillar Tractor Co. Oil cooled piston
EP0041416A1 (en) * 1980-05-30 1981-12-09 Societe D'etudes De Machines Thermiques S.E.M.T. Piston for a piston machine, especially for an internal-combustion engine
US4517930A (en) * 1982-09-28 1985-05-21 Kawasaki Jukogyo Kabushiki Kaisha Piston of combustion engine

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2317487A1 (en) * 1975-07-10 1977-02-04 Maschf Augsburg Nuernberg Ag DEVICE FOR COOLING, BY A LIQUID, OF WALLS SUBJECT TO THERMAL LOADS
US4286505A (en) * 1979-04-23 1981-09-01 Caterpillar Tractor Co. Oil cooled piston
EP0041416A1 (en) * 1980-05-30 1981-12-09 Societe D'etudes De Machines Thermiques S.E.M.T. Piston for a piston machine, especially for an internal-combustion engine
US4517930A (en) * 1982-09-28 1985-05-21 Kawasaki Jukogyo Kabushiki Kaisha Piston of combustion engine

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0373689A1 (en) * 1988-12-16 1990-06-20 KOLBENSCHMIDT Aktiengesellschaft Oil-cooled piston for internal-combustion engines
EP0464626B1 (en) * 1990-06-29 1995-10-18 KOLBENSCHMIDT Aktiengesellschaft Assembled oil cooled piston for diesel engines
EP0520536B1 (en) * 1991-06-25 1997-04-09 KOLBENSCHMIDT Aktiengesellschaft Assembled, oil cooled piston for Diesel engines
US6539836B2 (en) * 2000-06-07 2003-04-01 Honda Giken Kogyo Kabushiki Kaisha Piston for internal combustion engine

Also Published As

Publication number Publication date
EP0285205B1 (en) 1990-10-03
FI880884A0 (en) 1988-02-25
DE3709969A1 (en) 1988-10-06
DE3860721D1 (en) 1990-11-08
FI880884A (en) 1988-09-27

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