EP0449848B1 - Light plunger piston for internal combustion engines - Google Patents
Light plunger piston for internal combustion engines Download PDFInfo
- Publication number
- EP0449848B1 EP0449848B1 EP89912953A EP89912953A EP0449848B1 EP 0449848 B1 EP0449848 B1 EP 0449848B1 EP 89912953 A EP89912953 A EP 89912953A EP 89912953 A EP89912953 A EP 89912953A EP 0449848 B1 EP0449848 B1 EP 0449848B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- piston
- region
- shaft
- pressure side
- counterpressure
- 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
- F02F3/02—Pistons having means for accommodating or controlling heat expansion
-
- 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
- F02F3/02—Pistons having means for accommodating or controlling heat expansion
- F02F3/025—Pistons having means for accommodating or controlling heat expansion having circumferentially slotted piston skirts, e.g. T-slots
-
- 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
- F02F3/02—Pistons having means for accommodating or controlling heat expansion
- F02F3/022—Pistons having means for accommodating or controlling heat expansion the pistons having an oval circumference or non-cylindrical shaped skirts, e.g. oval
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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
Definitions
- the invention relates to a lightweight plunger for internal combustion engines according to the preamble of claim 1.
- the object of the invention is to improve the noise behavior of such a piston with the lowest possible weight and small dimensions in engine operation. At the same time, the piston should generate as little friction loss as possible during engine operation.
- the solution for the piston according to WO 88/08078 is to allow the piston to run obliquely with respect to its piston head in operating states in which the piston has not yet reached its temperature given in the nominal power mode.
- the piston skirt is provided with a corresponding contour, which changes as the operating heat rises of the piston changed so that the piston head is aligned parallel to the engine cylinder axis in the nominal power operation of the piston.
- the oblique position of the piston head at low temperature, which is given in the partial load range of the engine, is aimed at so that the piston head on the side on which it tends to strike the cylinder wall as a result of its tilting movement is kept as far away from the cylinder wall as possible can.
- the danger of striking the cylinder wall exists above all on the counter pressure side, which is why the piston head is inclined so that on the counter pressure side there is a greater distance between the top land and the cylinder wall than on the pressure side.
- the slot below the lowermost piston ring groove is provided in that known piston on the counter-pressure side in order to interrupt the flow of heat from the hot piston head into the underlying shaft area on that side. Such an interruption of the heat flow is necessary so that the shaft at the upper end expands radially outward as little as possible.
- the control strip attached to the upper piston end on the counterpressure side with a lower coefficient of thermal expansion than the shaft material also serves in that known piston.
- the combined measure of the slot and the thermal expansion-inhibiting control strip makes it possible for that piston to change the shaft contour on the counterpressure side in the direction of the connecting rod oscillation plane (plane, which is spanned in the piston axis and is perpendicular to the piston pin axis), which swivels the piston head into a position parallel to the cylinder axis with increasing piston temperature.
- plane which is spanned in the piston axis and is perpendicular to the piston pin axis
- the invention provides a generic piston with the characterizing features of claim 1.
- the piston skirt on the counter-pressure side is designed to be somewhat more flexible overall radially than on the pressure side.
- the running play on the counterpressure side compared to the cylinder running surface can be chosen to be less than on the pressure side.
- the longer shaft on the pressure side compared to the counter pressure side has the following effects in engine operation:
- the bolt axis is offset to the pressure side, causing a tilting moment which brings the piston into contact with the cylinder on its top land on the counter-pressure side.
- the longer shaft prevents the top land from striking in this way and thus increases piston noise.
- a piston is known from EP-A-0211189, the shaft of which can be designed as a whole asymmetrically as desired.
- the objective according to the invention is not addressed and certainly not solved in a comparable manner.
- the piston there does not have a horizontal slot between the piston head and the shaft on the counterpressure side. Such a slot is, however, absolutely necessary to achieve the result according to the invention.
- the piston according to that document lacks the additional measures (c) and (d) of the present patent claim 1 for the success according to the invention.
- a piston described in EP-A-0209006, in which the ovalities of the shaft on the pressure side and counter-pressure side are designed differently, is not comparable to the piston according to the invention because there is no combination of features comparable to the invention.
- the piston according to FIG. 1 has a longer shaft on the pressure side DS than the counter pressure side GDS.
- the wall thickness of the stem on the pressure side DS is greater than on the counter pressure side GDS, on which a horizontal slot separates the stem from the piston head within the lowest ring groove.
- the slot and the thinner wall thickness of the shaft ensure a certain elastic flexibility on the counter pressure side GDS, which should not be present on the pressure side.
- control strips inserted in the interior of the piston skirt of the piston according to FIG. 1 enable the skirt to be guided more closely when the piston is cold.
- the play between the upper shaft and cylinder area there in the cold state can be set lower than in the relevant shaft area on the pressure side.
- the straight lines O in FIGS. 4 and 5 indicate the cylinder track for the piston.
- the play between the piston skirt and the cylinder surface is zero.
- the distance between the curves GR, GB, DR and DB on the one hand and the straight line O on the other hand means the play of the piston running surface against the cylinder running surface.
- the curvature of the curves DR, DB and GR, GB corresponds to the respective piston outer shape.
- the piston skirt on the counter pressure side has less crowning in the upper skirt area than in the comparable area on the pressure side. Tighter guidance on the counter-pressure side is possible due to the overall more flexible design of the piston skirt on this piston side.
- the higher flexibility is achieved on the one hand by a horizontal slot between the stem and the piston head and on the other hand by the greater ovality of the piston skirt in the circumferential direction.
- the flexibility of the can be increased Piston shaft on the counter pressure side also in that the shaft thickness there is less than in the corresponding area on the pressure side.
- the piston according to FIG. 3 In order to be able to center the piston according to FIG. 3 both in the head and shaft area, it is designed to be symmetrical axially at heights A and B on its outer surface at least in regions.
- the stretch-regulating insert strip indicated by the dot-dash line in FIG. 3 lies axially on the counter pressure side higher than the upper shaft edge than on the pressure side.
- the ribs in the area of the pressure side of the piston can be made more solid and thus more stable than the ribs in question on the counter pressure side. It is also possible that such ribs are only attached to the pressure side of the hubs, which are otherwise freely formed on the piston crown, while they can be entirely absent on the counter-pressure side.
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Pistons, Piston Rings, And Cylinders (AREA)
Abstract
Description
Die Erfindung betrifft einen leichten Tauchkolben für Verbrennungsmotoren nach dem Oberbegriff des Patentanspruchs 1.The invention relates to a lightweight plunger for internal combustion engines according to the preamble of claim 1.
Es ist die Aufgabe der Erfindung, einen solchen Kolben bei möglichst geringem Gewicht und kleinen Abmessungen in seinem Gerauschverhalten im Motorbetrieb zu verbessern. Gleichzeitig soll der Kolben im Motorbetrieb möglichst geringe Reibleistungsverluste erzeugen.The object of the invention is to improve the noise behavior of such a piston with the lowest possible weight and small dimensions in engine operation. At the same time, the piston should generate as little friction loss as possible during engine operation.
Ein der erfindungsgemäßen Gattung entsprechender Kolben, mit dem im Prinzip die gleiche Aufgabe gelöst werden soll, ist aus WO 88/08078 bekannt. Der dort angestrebte Lösungsweg soll nach der vorliegenden Erfindung jedoch nicht beschritten werden.A piston corresponding to the genus according to the invention, with which the same object is to be achieved in principle, is known from WO 88/08078. However, the approach sought there should not be followed according to the present invention.
Die Lösung bei dem Kolben nach der WO 88/08078 besteht darin, den Kolben in Betriebszuständen, in denen der Kolben noch nicht seine im Nennleistungsbetrieb gegebene Temperatur erhalten hat, bezüglich seines Kolbenkopfes schrag laufen zu lassen. Zu diesem Zweck ist der Kolbenschaft mit einer entsprechenden Kontur versehen, die sich bei steigender Betriebswärme des Kolbens dahingehend verändert, daß der Kolbenkopf im Nennleistungsbetrieb des Kolbens parallel zu der Motorzylinderachse ausgerichtet ist. Die schräge Lage des Kolbenkopfes bei niedriger Temperatur, die im Teillastbereich des Motors gegeben ist, wird angestrebt, damit der Kolbenkopf auf derjenigen Seite, auf der er zu einem Anschlagen an die Zylinderwand in Folge seiner Kippbewegung neigt, möglichst weit von der Zylinderwand entfernt gehalten werden kann. Die Gefahr eines Anschlagens an die Zylinderwand besteht vor allem auf der Gegendruckseite, weshalb der Kolbenkopf so geneigt ist, daß auf der Gegendruckseite ein größerer Abstand des Feuersteges zur Zylinderwand gegeben ist als auf der Druckseite.The solution for the piston according to WO 88/08078 is to allow the piston to run obliquely with respect to its piston head in operating states in which the piston has not yet reached its temperature given in the nominal power mode. For this purpose, the piston skirt is provided with a corresponding contour, which changes as the operating heat rises of the piston changed so that the piston head is aligned parallel to the engine cylinder axis in the nominal power operation of the piston. The oblique position of the piston head at low temperature, which is given in the partial load range of the engine, is aimed at so that the piston head on the side on which it tends to strike the cylinder wall as a result of its tilting movement is kept as far away from the cylinder wall as possible can. The danger of striking the cylinder wall exists above all on the counter pressure side, which is why the piston head is inclined so that on the counter pressure side there is a greater distance between the top land and the cylinder wall than on the pressure side.
Der Schlitz unterhalb der untersten Kolbenringnut ist bei jenem vorbekannten Kolben auf der Gegendruckseite vorgesehen, um den Wärmefluss von dem heißen Kolbenkopf in den darunterliegenden Schaftbereich auf jener Seite zu unterbrechen. Eine solche Unterbrechung des Wärmeflusses ist notwendig, damit der Schaft sich am oberen Ende möglichst wenig unter Wärme nach radial außen ausdehnt. Zur Verhinderung einer solchen übermäßigen radialen Ausdehnung dient bei jenem vorbekannten Kolben zusätzlich noch der an dem oberen Kolbenschaftende auf der Gegendruckseite angebrachte Regelstreifen mit einem gegenüber dem Schaftmaterial niedrigeren Wärmeausdehnungskoeffizienten. Durch die kombinierte Maßnahme des Schlitzes und des wärmedehnungshemmenden Regelstreifens ist es bei jenem Kolben möglich, auf der Gegendruckseite eine Schaftkonturveränderung in Richtung der Pleuelschwingebene (Ebene, die in der Kolbenachse aufgespannt ist und senkrecht zur Kolbenbolzenachse steht) zu schaffen, die bei zunehmender Kolbentemperatur den Kolbenkopf in eine zu der Zylinderachse parallele Lage schwenkt.The slot below the lowermost piston ring groove is provided in that known piston on the counter-pressure side in order to interrupt the flow of heat from the hot piston head into the underlying shaft area on that side. Such an interruption of the heat flow is necessary so that the shaft at the upper end expands radially outward as little as possible. In order to prevent such an excessive radial expansion, the control strip attached to the upper piston end on the counterpressure side with a lower coefficient of thermal expansion than the shaft material also serves in that known piston. The combined measure of the slot and the thermal expansion-inhibiting control strip makes it possible for that piston to change the shaft contour on the counterpressure side in the direction of the connecting rod oscillation plane (plane, which is spanned in the piston axis and is perpendicular to the piston pin axis), which swivels the piston head into a position parallel to the cylinder axis with increasing piston temperature.
Das mit dieser Ausführungsform erzielbare Ergebnis soll durch eine Kolbenausführung nach der Erfindung noch weiter verbessert werden.The result that can be achieved with this embodiment is to be further improved by a piston design according to the invention.
Zu diesem Zweck sieht die Erfindung einen gattungsgemäßen Kolben mit den kennzeichnenden Merkmalen des Anspruches 1 vor.For this purpose, the invention provides a generic piston with the characterizing features of claim 1.
Zweckmäßige Ausgestaltungen der Erfindung sind Gegenstand der Unteransprüche.Appropriate embodiments of the invention are the subject of the dependent claims.
Durch die erfindungsgemäßen Maßnahmen ist der Kolbenschaft auf der Gegendruckseite insgesamt radial etwas nachgiebiger ausgestaltet als auf der Druckseite. Dadurch kann das Laufspiel auf der Gegendruckseite gegenüber der Zylinderlauffläche geringer gewählt werden als auf der Druckseite. Der auf der Druckseite gegenüber der Gegendruckseite längere Schaft wirkt sich im Motorbetrieb wie folgt aus:As a result of the measures according to the invention, the piston skirt on the counter-pressure side is designed to be somewhat more flexible overall radially than on the pressure side. As a result, the running play on the counterpressure side compared to the cylinder running surface can be chosen to be less than on the pressure side. The longer shaft on the pressure side compared to the counter pressure side has the following effects in engine operation:
Im oberen Totpunkt ergibt sich durch Desachsierung der Bolzenachse zur Druckseite ein Kippmoment, das den Kolben an seinem Feuersteg gegendruckseitig mit dem Zylinder in Berührung bringt. Der längere Schaft verhindert durch Reduzierung des Kippwinkels ein solches Anschlagen des Feuersteges und dadurch eine Kolbengeräuscherhöhung.At top dead center, the bolt axis is offset to the pressure side, causing a tilting moment which brings the piston into contact with the cylinder on its top land on the counter-pressure side. By reducing the tilt angle, the longer shaft prevents the top land from striking in this way and thus increases piston noise.
Im Stand der Technik ist aus EP-A-0211189 ein Kolben bekannt, dessen Schaft insgesamt beliebig unsymmetrisch gestaltbar ist. Bei dieser unsymmetrischen Schaftgestaltbarkeit ist jedoch ds erfindungsgemäße Ziel nicht angesprochen und schon gar nicht vergleichbar gelöst. Insbesondere weist der dortige Kolben auf der Gegendruckseite keinen horizontalen Schlitz zwischen Kolbenkopf und Schaft auf. Ein solcher Schlitz ist zur Erzielung des erfindungsgemäßen Ergebnisses jedoch unbedingt erforderlich. Des weiteren fehlen bei dem Kolben nach jener Schrift die für den erfindungsgemäßen Erfolg zusätzlich noch notwendigen Maßnahmen (c) und (d) des vorliegenden Patentanspruchs 1.In the prior art, a piston is known from EP-A-0211189, the shaft of which can be designed as a whole asymmetrically as desired. With this asymmetrical shaft design, however, the objective according to the invention is not addressed and certainly not solved in a comparable manner. In particular, the piston there does not have a horizontal slot between the piston head and the shaft on the counterpressure side. Such a slot is, however, absolutely necessary to achieve the result according to the invention. Furthermore, the piston according to that document lacks the additional measures (c) and (d) of the present patent claim 1 for the success according to the invention.
Auch ein in EP-A-0209006 beschriebener Kolben, bei dem die Ovalitäten des Schaftes auf Druck- und Gegendruckseite unterschiedlich ausgebildet sind, ist mit dem erfindungsgemäßen Kolben nicht vergleichbar, weil dort keine mit der Erfindung vergleichbaren Merkmalskombination vorliegt.A piston described in EP-A-0209006, in which the ovalities of the shaft on the pressure side and counter-pressure side are designed differently, is not comparable to the piston according to the invention because there is no combination of features comparable to the invention.
Ein Ausführungsbeispiel der Erfindung ist in der Zeichnung dargestellt. Es zeigt:
- Fig. 1
- einen Kolben im Längsschnitt
- Fig. 2a, b
- den Kolben im Schnitt nach Linie IIa bzw. IIb
- Fig. 3
- die Ansicht eines weiteren Kolbens
- Fig. 4
- den Mantellinienverlauf des Kolbens nach Fig. 3 in Druck-Gegendruckrichtung sowie in Bolzenrichtung jeweils auf der Druckseite des Kolbens
- Fig. 5
- den Mantellinienverlauf des Kolbens nach Fig. 3 in Druck-Gegendruckrichtung sowie in Bolzenrichtung jeweils auf der Gegendruckseite des Kolbens
- Fig. 6
- einen Schnitt durch den Kolben nach Linie VI - VI in Fig. 3
- Fig. 7
- Schaftumfangsverlauf auf den Höhen X und Y, jeweils als übereinander gezeichnete Kurven X, Y in übertriebener Darstellung des Kolbens nach Fig. 3
- Fig. 1
- a piston in longitudinal section
- 2a, b
- the piston in section along line IIa or IIb
- Fig. 3
- the view of another piston
- Fig. 4
- 3 in the pressure-counter-pressure direction and in the pin direction in each case on the surface line course of the piston the pressure side of the piston
- Fig. 5
- 3 in the pressure-counter pressure direction and in the bolt direction on the counter pressure side of the piston
- Fig. 6
- a section through the piston along the line VI - VI in Fig. 3rd
- Fig. 7
- Circumference of the shaft circumference at heights X and Y, in each case as curves X, Y drawn one above the other in an exaggerated representation of the piston according to FIG. 3
Der Kolben nach Fig. 1 weist auf der Druckseite DS einen längeren Schaft als der Gegendruckseite GDS auf. Außerdem ist die Wanddicke des Schaftes auf der Druckseite DS größer als auf der Gegendruckseite GDS, auf der innerhalb der untersten Ringnut ein horizontaler Schlitz den Schaft vom Kolbenkopf trennt. Der Schlitz und die geringere Wanddicke des Schaftes sorgen auf der Gegendruckseite GDS für eine gewisse elastische Nachgiebigkeit, die auf der Druckseite dagegen nicht vorhanden sein soll.The piston according to FIG. 1 has a longer shaft on the pressure side DS than the counter pressure side GDS. In addition, the wall thickness of the stem on the pressure side DS is greater than on the counter pressure side GDS, on which a horizontal slot separates the stem from the piston head within the lowest ring groove. The slot and the thinner wall thickness of the shaft ensure a certain elastic flexibility on the counter pressure side GDS, which should not be present on the pressure side.
Die im Inneren des Kolbenschaftes des Kolbens nach Fig. 1 eingelegten Regelstreifen ermöglichen eine engere Führung des Schaftes im Kaltzustand des Kolbens. Durch die auf der Gegendruckseite GDS gegenüber der Druckseite näher an dem oberen Schaftende vorgesehene Anordnung des Regelstreifens kann das Spiel ziwschen dortigem oberen Schaft- und Zylinderbereich im Kaltzustand geringer eingestellt werden als in dem betreffenden Schaftbereich auf der Druckseite.The control strips inserted in the interior of the piston skirt of the piston according to FIG. 1 enable the skirt to be guided more closely when the piston is cold. By the one provided on the counter pressure side GDS compared to the pressure side closer to the upper shaft end Arrangement of the control strip, the play between the upper shaft and cylinder area there in the cold state can be set lower than in the relevant shaft area on the pressure side.
In den Fig. 4 und 5 geben bei einem Kolben nach Fig. 3 den Mantellinienverlauf in Druck-Gegendruckrichtung jeweils die Kurven DR und DB auf der Druckseite sowie GR und GB auf der Gegendruckseite an.In FIGS. 4 and 5 the curves DR and DB on the pressure side as well as GR and GB on the pressure side indicate the surface line course in the pressure-counter pressure direction for a piston according to FIG. 3.
Die Geraden O in den Fig. 4 und 5 deuten die Zylinderlaufbahn für den Kolben an. In den Bereichen, in denen die Kurven DR bzw. GR die jeweilige Gerade O berühren, ist das Spiel zwischen dem Kolbenschaft und der Zylinderlauffläche gleich Null. Generell bedeutet der Abstand zwischen den Kurven GR, GB, DR und DB einerseits und den Geraden O andererseits das Spiel der Kolbenlauffläche gegenüber der Zylinderlauffläche.The straight lines O in FIGS. 4 and 5 indicate the cylinder track for the piston. In the areas in which the curves DR and GR touch the respective straight line O, the play between the piston skirt and the cylinder surface is zero. In general, the distance between the curves GR, GB, DR and DB on the one hand and the straight line O on the other hand means the play of the piston running surface against the cylinder running surface.
Die Krümmung der Kurven DR, DB und GR, GB entspricht der jeweiligen Kolbenaußenform. Wie ein Vergleich der Kurven GR und DR zeigt, besitzt der Kolbenschaft auf der Gegendruckseite eine geringere Balligkeit im oberen Schaftbereich als in dem vergleichbaren Bereich auf der Druckseite. Die engere Führung auf der Gegendruckseite ist durch die insgesamt nachgiebigere Ausbildung des Kolbenschaftes auf dieser Kolbenseite möglich. Die höhere Nachgiebigkeit wird zum einen durch einen horizontalen Schlitz zwischen dem Schaft und dem Kolbenkopf und zum anderen durch die größere Ovalität des Kolbenschaftes in Umfangsrichtung erreicht. Erhöht werden kann die Nachgiebigkeit des Kolbenschaftes auf der Gegendruckseite auch noch dadurch, daß die Schaftdicke dort geringer ist als in dem entsprechenden Bereich auf der Druckseite.The curvature of the curves DR, DB and GR, GB corresponds to the respective piston outer shape. As a comparison of the curves GR and DR shows, the piston skirt on the counter pressure side has less crowning in the upper skirt area than in the comparable area on the pressure side. Tighter guidance on the counter-pressure side is possible due to the overall more flexible design of the piston skirt on this piston side. The higher flexibility is achieved on the one hand by a horizontal slot between the stem and the piston head and on the other hand by the greater ovality of the piston skirt in the circumferential direction. The flexibility of the can be increased Piston shaft on the counter pressure side also in that the shaft thickness there is less than in the corresponding area on the pressure side.
Um den Kolben nach Fig. 3 sowohl im Kopf- und Schaftbereich zentrieren zu können, ist er axial auf den Höhen A und B auf seiner Außenoberfläche zumindest bereichsweise gegenüberliegend symmetrisch ausgebildet.In order to be able to center the piston according to FIG. 3 both in the head and shaft area, it is designed to be symmetrical axially at heights A and B on its outer surface at least in regions.
Der strickpunktiert in Fig. 3 angedeutete dehnungsregelnde Einlagestreifen liegt axial auf der Gegendruckseite höher zum oberen Schaftrand als auf der Druckseite.The stretch-regulating insert strip indicated by the dot-dash line in FIG. 3 lies axially on the counter pressure side higher than the upper shaft edge than on the pressure side.
Sind die von dem Kolbenboden ausgehenden in den Kolbeninnenraum ragenden Naben zur Aufnahme des Kolbenbolzens durch radial verlaufende Rippen gegen den Kolbenschaft abgestützt, so können die im Bereich der Druckseite des Kolbens liegenden Rippen massiver und damit stabiler ausgestaltet sein als die betreffenden Rippen auf der Gegendruckseite. Möglich ist es auch, daß derartige Rippen bei im übrigen frei an dem Kolbenboden angeformten Naben überhaupt nur auf der Druckseite angebracht sind, während sie auf der Gegendruckseite ganz fehlen können.If the hubs projecting from the piston crown into the interior of the piston for receiving the piston pin are supported against the piston skirt by radial ribs, the ribs in the area of the pressure side of the piston can be made more solid and thus more stable than the ribs in question on the counter pressure side. It is also possible that such ribs are only attached to the pressure side of the hubs, which are otherwise freely formed on the piston crown, while they can be entirely absent on the counter-pressure side.
Claims (3)
- Light-weight plunger piston for internal combustion engines, in particular passenger vehicle Otto engines, with the dimensions
L/D = 0.45 - 0.8
H/D = 0.25 - 0.5
A/D = 0.3 - 0.5
T/D = 0.45 - 0.8
withL = maximum length of the pistonD = maximum diameter of the pistonH = compression heightA = maximum shaft height below the lowermost annular groove in a peripheral region with approximately the same shaft height of at least 45 degrees on the pressure side of the piston with an approximately symmetrical division of this region on both sides of a plane extending through the longitudinal axis of the piston and stretching at right angles to the pin axisT = diametral mutual spacing of the radially external ends of the boss bore,and a shaft which is spherical in the axial direction of the piston and oval in the peripheral direction with the large axis of ovalness lying in the pressure/counter-pressure direction, which solely in its region located on the counterpressure side (GDS-region) is separated by a horizontal slot from the piston head, as well as in particular an axis of the boss bores for the piston pin, which is offset slightly towards the pressure side of the piston (offsetting of the pin axis), characterised by the features:a) in the polar plane (plane at right angles to the piston axis) in the region on the counterpressure side, the piston shaft has greater ovalness than in the region on the pressure side;b) in its upper region adjoining the lowermost annular groove, the shaft located in the region on the counter-pressure side has a less spherical construction than in the region on the pressure side;c) in the region of the pressure side the shaft is longer than in the region of the counterpressure side;d) the wall thickness on the pressure side is greater than that on the counterpressure side. - Plunger piston according to Claim 1, characterised in that in the region of the counterpressure side of the shaft an insert extending in the form of a strip in the peripheral direction of the shaft and regulating expansion is provided, which consists of a material whereof the coefficient of thermal expansion is less than that of the material of the shaft.
- Plunger piston according to Claim 2, characterised in that also provided on the pressure side is a strip-like insert regulating the expansion, which in comparison with the insert on the counterpressure side is at a greater distance from the upper shaft end.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3843866 | 1988-12-24 | ||
| DE3843761A DE3843761A1 (en) | 1988-12-24 | 1988-12-24 | Light trunk piston for internal combustion engines |
| DE3843761 | 1988-12-24 | ||
| DE3843866A DE3843866A1 (en) | 1988-12-24 | 1988-12-24 | Light trunk piston for internal combustion engines |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0449848A1 EP0449848A1 (en) | 1991-10-09 |
| EP0449848B1 true EP0449848B1 (en) | 1994-02-09 |
Family
ID=25875633
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP89912953A Expired - Lifetime EP0449848B1 (en) | 1988-12-24 | 1989-11-29 | Light plunger piston for internal combustion engines |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US5158008A (en) |
| EP (1) | EP0449848B1 (en) |
| JP (1) | JP2983621B2 (en) |
| KR (1) | KR970003153B1 (en) |
| BR (1) | BR8907852A (en) |
| DE (1) | DE58906955D1 (en) |
| WO (1) | WO1990007642A1 (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3931949A1 (en) * | 1989-09-25 | 1991-04-04 | Alcan Gmbh | PISTON FOR A COMBUSTION ENGINE |
| DE4110306A1 (en) * | 1990-09-20 | 1992-03-26 | Mahle Gmbh | SUBMERSIBLE ALLOY PISTON FOR OTTO ENGINES |
| JPH06257507A (en) * | 1993-03-09 | 1994-09-13 | Nissan Motor Co Ltd | Piston of internal combustion engine |
| DE4326978A1 (en) * | 1993-08-11 | 1995-02-16 | Alcan Gmbh | Pistons for internal combustion engines, in particular for diesel engines |
| JP3541511B2 (en) * | 1995-07-07 | 2004-07-14 | いすゞ自動車株式会社 | piston |
| DE19643778C2 (en) * | 1996-10-23 | 2000-04-13 | Alcan Gmbh | Lightweight pistons |
| CA2624119C (en) * | 2005-11-03 | 2015-02-17 | Dresser, Inc. | Piston |
| US7302884B2 (en) * | 2005-11-03 | 2007-12-04 | Dresser, Inc. | Piston |
| US7293497B2 (en) * | 2005-11-03 | 2007-11-13 | Dresser, Inc. | Piston |
| US9970384B2 (en) * | 2009-11-06 | 2018-05-15 | Federal-Mogul Llc | Steel piston with cooling gallery and method of construction thereof |
| US8807109B2 (en) * | 2009-11-06 | 2014-08-19 | Federal-Mogul Corporation | Steel piston with cooling gallery and method of construction thereof |
| US9470311B2 (en) | 2012-06-14 | 2016-10-18 | Mahle International Gmbh | Lightweight engine power cell assembly |
| KR101936468B1 (en) * | 2016-10-11 | 2019-01-08 | 현대자동차주식회사 | Piston Assembly with Improving Lubrication Performance |
| CN214787687U (en) * | 2020-11-20 | 2021-11-19 | 浙江春风动力股份有限公司 | Engine gear shifting device and motorcycle engine adopting same |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1499073A (en) * | 1919-09-04 | 1924-06-24 | Aluminum Co Of America | Piston |
| GB1256242A (en) * | 1968-09-05 | 1971-12-08 | Ass Eng Ltd | Improvements in pistons |
| US3908521A (en) * | 1972-07-31 | 1975-09-30 | Hepworth & Grandage Ltd | Pistons for internal combustion engines or for compressors |
| JPS601942B2 (en) * | 1982-04-15 | 1985-01-18 | 三菱マテリアル株式会社 | Sintered materials for cutting tools and wear-resistant tools with excellent high-temperature properties |
| DE3430132A1 (en) * | 1984-08-16 | 1986-02-27 | Mahle Gmbh, 7000 Stuttgart | ALUMINUM IMMERSION PISTON FOR COMBUSTION ENGINES WITH CONTROL STRIPS |
| DE3430258A1 (en) * | 1984-08-17 | 1986-02-27 | Mahle Gmbh, 7000 Stuttgart | SUBMERSIBLE PISTON FOR COMBUSTION ENGINES |
| IT1182507B (en) * | 1985-07-12 | 1987-10-05 | Ae Borgo Spa | PISTONS WITH ASYMMETRIC PROFILE FOR INTERNAL COMBUSTION ENGINES |
| DE3527032A1 (en) * | 1985-07-27 | 1987-01-29 | Mahle Gmbh | SUBMERSIBLE PISTON, IN PARTICULAR FOR COMBUSTION ENGINES |
| DE3820473C2 (en) * | 1986-12-18 | 1998-03-26 | Mahle Gmbh | Light plunger for internal combustion engines |
| DE3762445D1 (en) * | 1986-12-23 | 1990-05-31 | Mahle Gmbh | ONE-PIECE, LIGHTER AND LOW FRICTION ALLOY PISTON FOR COMBUSTION ENGINES. |
| US5000078A (en) * | 1987-04-18 | 1991-03-19 | Mahle Gmbh | Light metal trunk piston for internal combustion engines |
| JPS6457461A (en) * | 1987-08-28 | 1989-03-03 | Canon Kk | Recorder |
-
1989
- 1989-11-29 DE DE89912953T patent/DE58906955D1/en not_active Expired - Lifetime
- 1989-11-29 BR BR898907852A patent/BR8907852A/en not_active IP Right Cessation
- 1989-11-29 JP JP2500129A patent/JP2983621B2/en not_active Expired - Fee Related
- 1989-11-29 WO PCT/DE1989/000745 patent/WO1990007642A1/en active IP Right Grant
- 1989-11-29 EP EP89912953A patent/EP0449848B1/en not_active Expired - Lifetime
- 1989-11-29 KR KR1019900701873A patent/KR970003153B1/en not_active IP Right Cessation
- 1989-11-29 US US07/688,583 patent/US5158008A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| US5158008A (en) | 1992-10-27 |
| WO1990007642A1 (en) | 1990-07-12 |
| KR910700404A (en) | 1991-03-15 |
| EP0449848A1 (en) | 1991-10-09 |
| BR8907852A (en) | 1991-10-08 |
| JPH04502501A (en) | 1992-05-07 |
| KR970003153B1 (en) | 1997-03-14 |
| JP2983621B2 (en) | 1999-11-29 |
| DE58906955D1 (en) | 1994-03-24 |
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