EP0373689B1 - Oil-cooled piston for internal-combustion engines - Google Patents
Oil-cooled piston for internal-combustion engines Download PDFInfo
- Publication number
- EP0373689B1 EP0373689B1 EP89202981A EP89202981A EP0373689B1 EP 0373689 B1 EP0373689 B1 EP 0373689B1 EP 89202981 A EP89202981 A EP 89202981A EP 89202981 A EP89202981 A EP 89202981A EP 0373689 B1 EP0373689 B1 EP 0373689B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- piston
- ring
- groove
- oil
- bores
- 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 - Lifetime
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Classifications
-
- 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
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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
- F02F3/16—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
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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
- F05C2201/02—Light metals
- F05C2201/021—Aluminium
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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
- F05C2201/0433—Iron group; Ferrous alloys, e.g. steel
- F05C2201/0448—Steel
Definitions
- the invention relates to a piston with oil cooling for internal combustion engines, in particular for medium-speed diesel engines, consisting of a lower part receiving the piston pin and a central upper part with inlet openings for the lubricating oil provided cooling space and the upper part supporting the ring field, which are perpendicular in their plane of separation Support the circular bearing surfaces on the piston axis, which are arranged on concentric support collars, against each other, are clamped together by screws guided through the support collars and the support surfaces, have a circumferential empty groove in the area of their parting plane, provided by a circumferential empty groove on the inner or outer circumference of the upper surface , on the radial inside or outside of the support collar of the bearing surface of the lower part of the ring fit adjacent to each other are centered, the ring field two compression rings un d has an oil ring receiving ring grooves, from which an empty groove extending behind the ring field branches off and blind hole bores running parallel to the piston axis from the cooling chamber into the central part of the piston
- Such an oil-cooled piston for internal combustion engines described in DE-OS 37 09 969 has a lower weight due to a height of the top land of 6 to 15% of the piston diameter and a comparatively low compression height of 65 to 90% of the piston diameter and thus a small overall height.
- Adequate cooling of the piston crown and ring section is achieved in blind holes and, on the other hand, the necessary elasticity with good fatigue strength is achieved through the arrangement and design of the empty groove in the area of the plane of separation of the piston upper and lower piston parts and the associated circular-cylindrical section extending behind the ring section.
- the preferred embodiment of the invention is that the inclination of the holes connecting the circumferential groove to the blind holes is 65 to 90 °.
- the bores have a diameter of ⁇ 10 mm, preferably 2 to 6 mm.
- the width of the circumferential groove is expediently 5 to 20 mm and the depth 10 to 25 mm.
- this hole opens tangentially into the blind hole in order to ensure an optimal course of the cooling oil flow.
- the arrangement of the circumferential groove and the holes with a comparatively small diameter connecting the blind holes with the groove, from which the cooling oil emerges at high speed, and their position in relation to the parting plane, makes it possible that even in the exposed areas of the pipe, which rises radially with respect to the parting plane blind holes that run outwards, the heat that arrives there is transported away as quickly as possible and coking of the cooling oil is avoided or deposits are avoided.
- the drawing shows a segment of the oil-cooled piston designed according to the invention along the piston axis and the pin axis direction on the one hand and the piston axis and the plane including the direction perpendicular to the pin axis direction on the other hand in an axionometric representation.
- the piston is constructed from 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) .
- the lower part (2) and the upper part (5) are clamped together by 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 in a chord-like manner with respect to 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 in their separation plane perpendicular to the piston axis and are attached to support collars (8, 9).
- the expansion screws are led through the support collars (8,9) and the contact surfaces (10,11).
- a circumferential empty groove (13) with a circular cylindrical section (14) which branches off at right angles and runs parallel to the piston axis and extends behind the ring section.
- the ring section (4) has two ring grooves (15, 16) for receiving compression rings and one ring groove (17) for receiving an oil ring.
- the radially outward slope extends at an angle of 45 ° to the separation level blind holes (20) running behind the top land (21) and under the area of the rim of the piston crown.
- Coaxial blind holes (22) are arranged in the central part of the piston head in a hexagonal configuration, not shown.
- the lower part (2) can also consist of an aluminum piston alloy.
Landscapes
- 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)
Description
Die Erfindung betrifft einen Kolben mit Ölkühlung für Brennkraftmaschinen, insbesondere für mittelschnellaufende Dieselmotoren, bestehend aus einem den Kolbenbolzen aufnehmenden Unterteil und einem einen zentralen mit am Umfang befindlichen Zulauföffnungen für das Schmieröl versehenen Kühlraum begrenzenden und das Ringfeld tragenden Oberteil, die sich über in ihrer Trennungsebene senkrecht zur Kolbenachse liegende auf konzentrischen Abstützbunden angeordnete kreisförmige Auflageflächen 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 aufweisen, durch eine am Innen- oder Außenumfang der Auflagefläche des Oberteils angebrachte, an der radialen Innen- bzw. Außenseite des Abstützbundes der Auflagefläche des Unterteils anliegende Ringpassung gegeneinander zentriert sind, das Ringfeld zwei Kompressionsringe und einen Ölring aufnehmende Ringnuten aufweist, von der Leernut eine sich hinter das Ringfeld erstreckende Leernut abzweigt und sich vom Kühlraum aus parallel zur Kolbenachse verlaufende Sacklochbohrungen in den mittleren Teil des Kolbenbodens sowie vom Umfang des Kühlraums aus gegenüber der Trennungsebene ansteigend geneigte radial nach außen verlaufende Sacklochbohrungen bis in den Bereich hinter den Feuersteg und den Rand des Kolbenbodens erstrecken.The invention relates to a piston with oil cooling for internal combustion engines, in particular for medium-speed diesel engines, consisting of a lower part receiving the piston pin and a central upper part with inlet openings for the lubricating oil provided cooling space and the upper part supporting the ring field, which are perpendicular in their plane of separation Support the circular bearing surfaces on the piston axis, which are arranged on concentric support collars, against each other, are clamped together by screws guided through the support collars and the support surfaces, have a circumferential empty groove in the area of their parting plane, provided by a circumferential empty groove on the inner or outer circumference of the upper surface , on the radial inside or outside of the support collar of the bearing surface of the lower part of the ring fit adjacent to each other are centered, the ring field two compression rings un d has an oil ring receiving ring grooves, from which an empty groove extending behind the ring field branches off and blind hole bores running parallel to the piston axis from the cooling chamber into the central part of the piston crown and from the circumference of the cooling chamber from the cooling chamber inclining radially outwardly extending blind hole bores extend to the area behind the top land and the edge of the piston crown.
Ein solcher in der DE-OS 37 09 969 beschriebener ölgekühlter Kolben für Brennkraftmaschinen besitzt infolge einer Höhe des Feuerstegs von 6 bis 15 % des Kolbendurchmessers sowie einer vergleichsweise niedrigen Kompressionshöhe von 65 bis 90 % des Kolbendurchmessers und damit kleinen Bauhöhe ein niedrigeres Gewicht. Durch die Anordnung der eine große Kühloberfläche schaffenden Sacklochbohrungen wird eine hinreichende 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 von Kolbenober- und Kolbenunterteil und des damit verbundenen kreiszylinderförmigen, sich hinter die Ringpartie erstreckenden Abschnitts erreicht.Such an oil-cooled piston for internal combustion engines described in DE-OS 37 09 969 has a lower weight due to a height of the top land of 6 to 15% of the piston diameter and a comparatively low compression height of 65 to 90% of the piston diameter and thus a small overall height. By arranging the large cooling surface Adequate cooling of the piston crown and ring section is achieved in blind holes and, on the other hand, the necessary elasticity with good fatigue strength is achieved through the arrangement and design of the empty groove in the area of the plane of separation of the piston upper and lower piston parts and the associated circular-cylindrical section extending behind the ring section.
Es hat sich jedoch im Motorbetrieb herausgestellt, daß sich auf den Wänden, insbesondere der gegenüber der Trennungsebene ansteigend geneigten radial nach außen verlaufenden Sacklochbohrungen Ablagerungen ausbilden, die den Wärmeübergang vom Randbereich des Kolbenbodens sowie vom Bereich des Feuerstegs und der ersten Ringnut auf das Kühlöl erheblich beeinträchtigen. Ursache hierfür sind relativ hohe Oberflächentemperaturen infolge mangelnder Kühlwirkung durch ungenügende Füllung der äußeren Kühlölbohrungen sowie mangelnder Shaker- und Waschwirkung des Kühlöls. Diese beiden Wirkungen lassen sich durch Filmaufnahmen am Shaker-Prüfstand nachweisen.However, it has been found in engine operation that deposits form on the walls, in particular the radially outwardly extending blind bores, which incline with respect to the plane of separation, which significantly impair the heat transfer from the edge area of the piston crown and from the area of the top land and the first annular groove to the cooling oil . The reason for this are relatively high surface temperatures due to a lack of cooling effect due to insufficient filling of the outer cooling oil holes as well as a lack of shaker and washing effects of the cooling oil. These two effects can be demonstrated by filming on the shaker test bench.
Es ist daher die Aufgabe der vorliegenden Erfindung, den eingangs beschriebenen ölgekühlten Kolben so auszubilden, daß eine verbesserte Waschwirkung des Kühlöls auf die Wände der gegenüber der Trennungsebene ansteigend geneigten radial nach außen verlaufenden Sacklochbohrungen und deren bessere Füllung erzielt wird, wobei allerdings die Temperatur im Bereich der ersten Ringnut wegen der bestehenden Korrosionsgefahr 180°C nicht unterschreiten sollte.It is therefore the object of the present invention to design the oil-cooled piston described at the outset in such a way that an improved washing effect of the cooling oil on the walls of the blind bore holes which are inclined with increasing inclination with respect to the plane of separation and their better filling is achieved, although the temperature in the range the first ring groove should not drop below 180 ° C due to the existing risk of corrosion.
Gelöst ist diese Aufgabe dadurch, daß in dem Abstützbund des Unterteils eine mit der Öffnung in der Trennungsebene liegende umlaufende, in den Kühlölkreislauf integrierte Rille angebracht ist und jede gegenüber der Trennungsebene ansteigend geneigte radial nach außen verlaufende Sacklochbohrung über wenigstens eine gegenüber der Trennungsebene ansteigend größer als die Sacklochbohrung geneigte radial nach außen verlaufende Bohrung mit der Rille verbunden ist.This object is achieved in that in the supporting collar of the lower part there is a circumferential groove with the opening in the parting plane, integrated in the cooling oil circuit, and each radially outwardly extending blind hole which is inclined with respect to the parting plane via at least one with respect to the Separation level is greater than the blind hole inclined radially outwardly extending hole is connected to the groove.
Die vorzugsweise Ausgestaltung der Erfindung besteht darin, daß die Neigung der die umlaufende Rille mit den Sacklochbohrungen verbindenden Bohrungen 65 bis 90° beträgt.The preferred embodiment of the invention is that the inclination of the holes connecting the circumferential groove to the blind holes is 65 to 90 °.
Die Bohrungen besitzen zur Erzeugung einer hohen Strömungsgeschwindigkeit einen Durchmesser von < 10 mm, vorzugsweise 2 bis 6 mm.To produce a high flow rate, the bores have a diameter of <10 mm, preferably 2 to 6 mm.
Zweckmäßigerweise beträgt die Breite der umlaufenden Rille 5 bis 20 mm und die Tiefe 10 bis 25 mm.The width of the circumferential groove is expediently 5 to 20 mm and the depth 10 to 25 mm.
Im Rahmen der weiteren Ausbildung der Erfindung mündet diese Bohrung tangential in der Sacklochbohrung, um einen optimalen Verlauf der Kühlölströmung zu gewährleisten.As part of the further development of the invention, this hole opens tangentially into the blind hole in order to ensure an optimal course of the cooling oil flow.
Die Anordnung der umlaufenden Rille und der die Sacklochbohrungen mit der Rille verbindenden Bohrungen mit vergleichsweise kleinem Durchmesser, aus denen das Kühlöl mit hoher Geschwindigkeit austritt, sowie deren Lage bezogen auf die Trennungsebene ermöglicht, daß auch in den exponierten Bereichen der gegenüber der Trennungsebene ansteigend geneigten radial nach außen verlaufenden Sacklochbohrungen die dort einfallende Wärme so schnell wie möglich abtransportiert wird und die Verkokung des Kühlöls unterbleibt bzw. Ablagerungen vermieden werden.The arrangement of the circumferential groove and the holes with a comparatively small diameter connecting the blind holes with the groove, from which the cooling oil emerges at high speed, and their position in relation to the parting plane, makes it possible that even in the exposed areas of the pipe, which rises radially with respect to the parting plane blind holes that run outwards, the heat that arrives there is transported away as quickly as possible and coking of the cooling oil is avoided or deposits are avoided.
Die Zeichnung zeigt ein Segment des erfindungsgemäß gestalteten ölgekühlten Kolbens entlang der Kolbenachse und der Bolzenachsrichtung einerseits sowie der Kolbenachse und der Richtung senkrecht zur Bolzenachsrichtung einschließenden Ebenen andererseits in axionometrischer Darstellung.The drawing shows a segment of the oil-cooled piston designed according to the invention along the piston axis and the pin axis direction on the one hand and the piston axis and the plane including the direction perpendicular to the pin axis direction on the other hand in an axionometric representation.
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. Das Unterteil (2) und das Oberteil (5) sind durch nicht dargestellte Dehnschrauben miteinander verspannt. 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 Innenumfang der Auflagefläche (11) des Oberteils (5) ist eine Ringpassung (12) angebracht, die an der Innenseite 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 erstreckenden kreiszylinderförmigen Abschnitt (14). Die Ringpartie (4) weist zwei Ringnuten (15,16) für die Aufnahme von Kompressionsringen und eine Ringnut (17) für die Aufnahme eines Ölrings auf. Vom Umfang des Kühlraums (3), der kolbenfußseitig durch einen gewölbeartig gestalteten und mit den Naben 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 Kolbenbodens in nicht dargestellter Sechseckkonfiguration angeordnet. In dem Abstützbund (8) des Unterteils (2) ist eine mit der Öffnung in der Auflagefläche (10) liegende umlaufende Rille (23) angebracht, der über mehrere nicht dargestellte parallel zur Kolbenachse verlaufende Bohrungen Kühlöl zugeführt wird. Die gegenüber der Trennungsebene ansteigend geneigten radial nach außen verlaufenden Sacklochbohrungen (20) sind über gegenüber der Trennungsebene stärker als die Sacklochbohrungen (20) geneigte radial nach außen durch den Abstützbund (9) des Oberteils (5) verlaufende Bohrungen (24) mit der Rille (23) verbunden und treten tangential in die Sacklochbohrungen (20) ein. Das Unterteil (2) kann auch aus einer Aluminium-Kolbenlegierung bestehen.The piston is constructed from 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) . The lower part (2) and the upper part (5) are clamped together by 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 in a chord-like manner with respect to 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 in their separation plane perpendicular to the piston axis and are attached to support collars (8, 9). The expansion screws are led through the support collars (8,9) and the contact surfaces (10,11). On the inner circumference of the support surface (11) of the upper part (5) there is an annular fit (12) which is centered on the inside 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 circular cylindrical section (14) which branches off at right angles and runs parallel to the piston axis and extends behind the ring section. The ring section (4) has two ring grooves (15, 16) for receiving compression rings and one ring groove (17) for receiving an oil ring. From the circumference of the cooling chamber (3), which is closed on the piston foot side by a vault-like bottom (18) with a drain opening (19) for the cooling oil, the radially outward slope extends at an angle of 45 ° to the separation level blind holes (20) running behind the top land (21) and under the area of the rim of the piston crown. Starting from the refrigerator (3) are also Coaxial blind holes (22) are arranged in the central part of the piston head in a hexagonal configuration, not shown. In the support collar (8) of the lower part (2) there is a circumferential groove (23) with the opening in the support surface (10), to which cooling oil is supplied via several bores (not shown) running parallel to the piston axis. The blind bore holes (20), which are inclined radially outwards and increase in relation to the plane of separation, are bores (24) with the groove (24) which run radially outward more than the blind hole bores (20) through the support collar (9) of the upper part (5) and have the groove ( 23) and enter tangentially into the blind holes (20). The lower part (2) can also consist of an aluminum piston alloy.
Der mit der Erfindung erzielte Vorteil ist insbesondere darin zu sehen, daß die Ausbildung einer Koksschicht bzw. von Ablagerungen auf den gegenüber der Trennungsebene ansteigend geneigten radial nach außen verlaufenden Sacklochbohrungen unterbleibt, ohne daß die vorteilhaften Wirkungen des Kolbens beeinträchtigt werden.The advantage achieved with the invention is to be seen in particular in the fact that the formation of a coke layer or of deposits on the radially outwardly extending blind bores which are inclined with respect to the plane of separation does not occur without the advantageous effects of the piston being impaired.
Claims (5)
- An oil-cooled piston for internal combustion engines, in particular for medium-speed diesel engines, consisting of a lower section (2) which receives the gudgeon pin (1) and an upper section (5) which delimits a central cooling chamber (3) provided with inlet openings for the cooling oil located on the periphery and bears the ring-carrying zone (4), which sections are supported on one another by means of circular bearing surfaces (10, 11) located in their division plane perpendicular to the piston axis and located on concentric supporting collars (8, 9), are braced together by means of screws which pass through the supporting collars (8, 9) and the bearing surfaces (10, 11), have a circumambient empty groove (13) made from the outer periphery inwards in the region of their division plane, are centred relative to one another by a ring fit (12) made on the inner or outer periphery of the bearing surface (11) of the upper section (5) and bearing on the radial inside or outside of the supporting collar (8) of the bearing surface (10) of the lower section (2), the ring-carrying zone (4) has annular grooves (15, 16, 17) which receive two compression rings and one oil-control ring, an empty groove (14) which extends behind the ring-carrying zone (4) branches off from the empty groove (13) and blind holes (22) running out from the cooling chamber (3) parallel to the piston axis extend into the middle section of the piston head (6) and also blind holes (20) running radially outwards also extend out from the periphery of the cooling chamber (3) inclined upwards relative to the division plane into the region behind the top land (21) and the edge of the piston head (6), characterised in that a circumambient groove (23) having its opening located in the plane of the bearing surface (10) is made in the supporting collar (8) of the lower section (2) and each blind hole (20) which runs radially outwards inclined upwards relative to the division plane is connected to the groove (23) by means of at least one bore (24) which runs radially outwards through the supporting collar (9) of the upper section (5) ascending relative to the division plane and which is inclined more steeply than the blind hole (20).
- A piston according to Claim 1, characterised in that the inclination of the bores (24) is 65 to 90°.
- A piston according to Claims 1 and 2, characterised in that the bores (24) have a diameter of < 10 mm, preferably 2 to 6 mm.
- A piston according to Claims 1 to 3, characterised in that the width of the groove (23) is 5 to 20 mm and the depth is 10 to 25 mm.
- A piston according to one or more of Claims 1 to 3, characterised in that the bores (24) open tangentially into the blind holes (20).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3842321 | 1988-12-16 | ||
| DE3842321A DE3842321A1 (en) | 1988-12-16 | 1988-12-16 | PISTON WITH OIL COOLING FOR INTERNAL COMBUSTION ENGINES |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0373689A1 EP0373689A1 (en) | 1990-06-20 |
| EP0373689B1 true EP0373689B1 (en) | 1993-01-20 |
Family
ID=6369274
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP89202981A Expired - Lifetime EP0373689B1 (en) | 1988-12-16 | 1989-11-23 | Oil-cooled piston for internal-combustion engines |
Country Status (2)
| Country | Link |
|---|---|
| EP (1) | EP0373689B1 (en) |
| DE (2) | DE3842321A1 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI106396B (en) * | 1998-11-19 | 2001-01-31 | Wecometal Oy | Internal combustion piston |
| DE10244510A1 (en) * | 2002-09-25 | 2004-04-08 | Mahle Gmbh | One-piece cooling channel piston for an internal combustion engine |
| DE102004027974A1 (en) * | 2004-06-08 | 2005-12-29 | Mahle Gmbh | A built piston and method of preventing damage in contact surfaces of the top and bottom of the piston |
| KR20180078251A (en) * | 2015-11-02 | 2018-07-09 | 카에스 콜벤슈미트 게엠베하 | Optimized hub support |
| US10704491B2 (en) * | 2018-10-11 | 2020-07-07 | Tenneco Inc. | Piston cooling gallery shaping to reduce piston temperature |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE873185C (en) * | 1948-03-22 | 1953-04-13 | Napier & Son Ltd | Pistons, especially for internal combustion engines |
| DE1119601B (en) * | 1957-01-15 | 1961-12-14 | Karl Schmidt Ges Mit Beschraen | Device for cooling light metal pistons for internal combustion engines |
| FR2483521A1 (en) * | 1980-05-30 | 1981-12-04 | Semt | PISTON OF ALTERNATIVE PISTON MACHINE, ESPECIALLY OF INTERNAL COMBUSTION ENGINE |
| DE3709969A1 (en) * | 1987-03-26 | 1988-10-06 | Kolbenschmidt Ag | PISTON WITH LIQUID COOLING |
-
1988
- 1988-12-16 DE DE3842321A patent/DE3842321A1/en not_active Withdrawn
-
1989
- 1989-11-23 DE DE8989202981T patent/DE58903352D1/en not_active Expired - Fee Related
- 1989-11-23 EP EP89202981A patent/EP0373689B1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| DE58903352D1 (en) | 1993-03-04 |
| DE3842321A1 (en) | 1990-06-21 |
| EP0373689A1 (en) | 1990-06-20 |
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