EP0210649B1 - Light-weight metal piston - Google Patents

Light-weight metal piston Download PDF

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Publication number
EP0210649B1
EP0210649B1 EP86110453A EP86110453A EP0210649B1 EP 0210649 B1 EP0210649 B1 EP 0210649B1 EP 86110453 A EP86110453 A EP 86110453A EP 86110453 A EP86110453 A EP 86110453A EP 0210649 B1 EP0210649 B1 EP 0210649B1
Authority
EP
European Patent Office
Prior art keywords
piston
insert
sleeve
exposed
shaped insert
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP86110453A
Other languages
German (de)
French (fr)
Other versions
EP0210649A3 (en
EP0210649A2 (en
Inventor
Gerhard Dipl.-Ing. Böhm
Helmut Zweck
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Novelis Deutschland GmbH
Original Assignee
Alcan Deutschland GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Alcan Deutschland GmbH filed Critical Alcan Deutschland GmbH
Priority to AT86110453T priority Critical patent/ATE48895T1/en
Publication of EP0210649A2 publication Critical patent/EP0210649A2/en
Publication of EP0210649A3 publication Critical patent/EP0210649A3/en
Application granted granted Critical
Publication of EP0210649B1 publication Critical patent/EP0210649B1/en
Expired legal-status Critical Current

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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
    • F02F3/04—Pistons  having means for accommodating or controlling heat expansion having expansion-controlling inserts
    • F02F3/08—Pistons  having means for accommodating or controlling heat expansion having expansion-controlling inserts the inserts being ring-shaped
    • 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
    • F02F3/04—Pistons  having means for accommodating or controlling heat expansion having expansion-controlling inserts
    • F02F3/045—Pistons  having means for accommodating or controlling heat expansion having expansion-controlling inserts the inserts being located in the crown
    • 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
    • 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
    • F05C2251/00—Material properties
    • F05C2251/04—Thermal properties
    • F05C2251/042—Expansivity

Definitions

  • the invention relates to a piston made of light metal for internal combustion engines with a self-contained, sleeve-shaped insert made of a metal of lower thermal expansion than the piston base material which is arranged in the solid material of the piston crown and controls the thermal expansion of the piston, the insert extending over the entire piston circumferential angle of 360 ° and has at least one edge or a side that reaches the outer piston surfaces facing the combustion chamber and / or top land and is exposed on these piston surfaces by the piston material, the piston material on the inside of the insert facing the piston axis, forming a gap from the Insert has shrunk. This shrinking occurs during cooling after the insert has been poured into the piston base material due to its greater coefficient of thermal expansion.
  • the piston base material located on the outside of the insert has shrunk onto the insert, as a result of which the latter has been subjected to a tensile prestress. Since the temperatures that occurred during the pouring of the control insert into the piston skirt cannot be reached again during engine operation, this shrinkage only partially decreases during engine operation, as a result of which the gap formed on the inside of the piston when the freshly cast piston cools due to shrinkage Rule deposit not fully reversed.
  • a piston of the aforementioned type with a control insert arranged in the piston crown, which has at least one edge or a side which or which reaches the outer piston surfaces facing the combustion chamber and / or top land, is already known (DE-C 630 440).
  • This exposure of the control insert on the sides or edges of this known piston on the piston crown gives rise to problems with regard to the fatigue strength of the relatively thin, shell-shaped outer part of the piston crown located on the outside of the control insert, with the engine operating to cause this part to come off and possibly even the regular deposit can come.
  • oil can penetrate into the gap created on one side of the control insert and also remains during engine operation due to the shrinking, which cokes there at the high combustion temperatures and is deposited as oil carbon, whereby the gap is gradually added and the Control effect is more and more restricted or ultimately prevented.
  • a piston is known with a sleeve-shaped insert arranged in the solid material of the piston crown, which, like that in the aforementioned known piston, extends over the entire piston circumferential angle of 360 ° and has an exposed edge or an exposed side, which, however, does not serve as a control insert but instead to cause heat reflection and / or heat dissipation from heat-sensitive points in order to lower the temperature at these points (GB-A 530 570).
  • pistons with control inserts arranged in the region of the piston skirt are known, which likewise extend over the entire piston circumference and are exposed on at least one edge or one side of piston material of the piston skirt (DE-B 1 073 257).
  • pistons with inserts arranged in the piston head namely the risk of the piston parts located on the outside of the insert jumping off and possibly even the insert, and of the gap formed by shrinking free from coking oil.
  • the object of the invention is to ensure a locally limited control, that is to say only occurring in certain segments of the piston head, in a piston of the type mentioned above and, at the same time, to ensure that the control insert is firmly anchored in the piston material in order to prevent it from being flung away to prevent the insert or parts of the piston head.
  • the clogging of the shrink gap with coking oil coal should be prevented.
  • This object is achieved according to the invention in that the edge or the side of the insert is only exposed in certain segment areas of the piston, but in the other segment areas lies below the outer piston surface, i.e.
  • the insert according to the invention can e.g. be exposed with its one lower edge or its lower side to the piston side wall or to a piston ring groove. It may also be expedient for the insert to have a kink or rounding in cross-section and to lie with it or with its entire outside on the piston side wall, that is to say it is exposed on the latter. It is also possible to provide the annular groove with at least a partial reinforcement with one of the cut-off ends of the control insert.
  • the piston is provided with its base material with reference number 1, the upper annular groove with reference number 2, the bolt eye with reference number 3 and the pin bore with reference number 4 in all exemplary embodiments.
  • the piston end face 5 is recessed to form a central combustion chamber 6.
  • the piston side wall has the reference number 8.
  • the free shrink gap which is located directly on the inside of the control insert facing the piston vertical axis 13, is not shown in the drawings.
  • the insert 7 extends slightly inside (under) the piston side wall 8 in a ring over the entire piston circumference, its ring shape being straightened on two opposite segment areas 9, so that in these segment areas of the piston head
  • the insert is located at a somewhat greater distance from the piston side wall 8 than in its circular segment regions 10.
  • this insert has an L-shaped sleeve cross section, one cross-sectional leg 11 being located on the piston end face 5 and the one that did not arise on the inside of the insert drawn shrink gap covers. The sleeve-shaped insert is thus exposed with this leg 11 on the piston end face. With the edge of its other leg 12, this insert is exposed in the said segment area on the piston ring groove 2.
  • the cross section of the insert is reduced from its other L-shape to a relatively small part of the L-leg 12, in such a way that this segment area 9 is embedded and anchored on all sides in the piston base material 1 .
  • the straightened and small cross-sectional segment regions 9 of the insert 7 are located above the bolt eyes 3, while the L-shaped cross-sectional regions 10 of the insert are 90 ° with respect to the piston vertical axis 13 Piston cross-section are offset so that they are laterally above the pin eyes 3.
  • the insert 14 has the same shape as the insert 7 in the embodiment according to FIGS. 1 and 2. It is also arranged in the piston in the same way as in this embodiment, with the exception that the Segment areas 15 with a larger L-shaped cross section are located above the pin eyes 3, while the straightened segment areas 16 with the reduced cross section are offset laterally above the pin eyes 3 with respect to the piston vertical axis by 90 ° in the piston cross section.
  • the exemplary embodiment according to FIGS. 6 and 7 has an insert 17 which, in its circular segment regions 8 located above the bolt eyes 3, has a U-shaped cross section, the upper leg covering the free shrink gap on the piston end face 5 and the lower leg the upper ring groove 2 is exposed. In its straightened segment areas 19, the insert 17 is limited in cross section to the lower part of the U-web.
  • FIGS. 8 and 9 differs from that according to FIGS. 6 and 7 only in that the insert 20 with its straightened segment areas 21 is above the bolt eyes 3 and with its segment areas 22 located therebetween laterally above the bolt eyes.
  • the insert 23 extends in a ring at a short distance within the piston side wall 8 around the circumference of the piston and has two circular segment areas 24 and two straightened segment areas 25 therebetween.
  • the insert 23 has larger ones in the circular segment areas Cross-section than in its straightened segment regions 25, wherein in its upper cross-sectional region it is bent in the direction of the piston side wall 8 and is exposed on this piston side wall. With its lower edge, it is exposed in the piston ring groove 2 in these segment areas.
  • this insert 23 In its straightened segment regions 25, this insert 23 has a reduced cross-section, which corresponds to the cross-sectional part of the insert located below the aforementioned bend in the circular segment region 24.
  • the insert is supported in all of its segment areas below the piston face 5 in the piston base material 1 and is therefore covered by this. A free shrink gap open to the combustion chamber is therefore not provided in this embodiment either. In its straightened segment regions 25, the insert lies completely surrounded by the piston base material within the piston side wall and is also not exposed on a piston ring groove.
  • the straightened segment regions 25 of the insert 23 embedded on all sides in the piston base material 1 are located above the bolt eyes 3, while the exposed segment regions 24 are offset by 90 ° with respect to the piston vertical axis 13 in the piston cross section.
  • the insert 26 has the same shape as the insert 23 in the embodiment according to FIGS. 10 and 11. However, it is arranged in the piston crown in such a way that its exposed circular segment regions 27 are located above the bolt eyes 3 .
  • the exemplary embodiment according to FIGS. 14 and 15 differs from that according to FIGS. 10 and 11 only in that the insert 28 in its annular segment regions 29 still has a cross-sectional part 30 located below the upper piston ring groove 2 and reinforcing this groove, which, like that Upper cross-sectional part 31 is connected to the straightened segment areas 32.
  • the ring-shaped segment regions 29 of the insert 28 with their full cross-section are located laterally above the bolt eyes 3, while the straightened small cross-section segment regions 32 lie above the bolt eyes 3.
  • an inverted position of the different segment areas 28, 32 is also possible.
  • the control insert 33 is not exposed on the piston end face 5 but on the piston side wall 8, so that the free shrink gap is covered by the piston base material 1 with respect to the combustion chamber.
  • the insert is U-shaped in cross-section in two opposite segment areas 34 located above the bolt eyes 3, the edges of the U-legs being exposed on the piston side wall 8.
  • the lower U-leg is also exposed on the upper piston ring groove 2.
  • the insert 33 is reduced in its cross section approximately to the lower cross-sectional half of the other two segment areas 34, so that the insert in these segment areas only with its lower edge in the piston ring groove 2 and is exposed on the piston side wall 8.
  • FIGS. 18 and 19 differs only from that of FIGS. 16 and 17 in that the insert 36 with its U-shaped cross-section has segment region 37 laterally above the bolt eyes 3 and with its approximately on the lower half of this U- Cross-section reduced cross-section segment areas 38 is located above the bolt eyes 3.
  • the exemplary embodiment according to FIGS. 20 to 22 differs from that according to FIGS. 16 and 17 only in that the insert 39 there has an S-shape in the two segment areas located above the bolt eyes 3, the upper S-leg 40 on the Piston end face 5 is exposed and the lower S-leg on the piston side wall 8 and in the upper annular groove 2.
  • the insert 39 is in cross-section on the lower half of the in the the aforementioned segment areas given S-shaped cross-section reduced, so that there the insert is only exposed on the Cologne side wall 8 and in the upper annular groove 2.
  • the free shrink gap is thus covered in the two segment areas with an S cross section by the upper S leg 40 and in the two other segment areas 41 by the piston base material 1.
  • the exemplary embodiment according to FIGS. 23 and 24 has an insert 42 of the same design as the exemplary embodiment according to FIGS. 20 and 21, but this insert, with its segment areas 43 having a full S cross section, is arranged laterally above the bolt eyes 3, while its reduced cross-section segment regions 44 are located directly above the bolt eyes 3.
  • the insert 45 has a U-shaped cross-section in the two segment regions 46 lying laterally above the bolt eyes 3 and is exposed with its entire outside on the piston side wall 8, with its upper U-leg on the Piston face and its lower U-leg are exposed on the upper annular groove 2.
  • segment regions 47 located above the bolt eyes 3 lie at a certain distance within the piston side wall 8.
  • the insert has a rectangular cross section of smaller dimensions than in its other segment regions 46, all of them tig surrounded by the piston base material 1 and thus firmly anchored in this.
  • the main desired effect of this type of insert is based on the shrinking of the piston base material located on the inside of the insert.
  • the second effect of such a regulating sleeve namely placing the piston base material layer on the outside of the regulating insert by shrinking onto the insert at lower temperatures under tensile stress and thus rendering some of its expansion ineffective during subsequent engine operation becomes ineffective in the latter embodiment improved to the effect that the outer layer of the piston base body is completely eliminated in segments and only the lower coefficient of expansion of the material of the control insert is effective there with regard to the play between the piston crown and the cylinder wall in the engine.
  • control insert 48 has two circularly curved segment regions 49, in which the insert has a rectangular cross section and its entire outside is exposed on the piston outer surface 8. Furthermore, it has two segment areas 50, also of rectangular cross-section, located above the bolt eyes 3, which extend in a straight line within the piston side wall 8 and are surrounded on all sides by the piston base body and are thus firmly anchored in the latter.
  • the upper annular groove 2 is provided with an additional reinforcement 51 with a U-shaped cross section, as is customary in the prior art, in particular for pistons for diesel engines.

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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)
  • Glass Compositions (AREA)
  • Telephone Function (AREA)
  • Electrochromic Elements, Electrophoresis, Or Variable Reflection Or Absorption Elements (AREA)

Abstract

Light-metal piston for combustion engines, having a sleeve-like insert embedded therein and controlling its heat expansion and being formed of a metal of smaller heat expansion coefficient than the piston base material. The insert is arranged in the solid material of the piston crown and extends around the entire piston periphery. Behind the insert, the piston base material is self-contracted to form a gap delimited by the insert on one side. On at least one edge or one side, the insert is not covered by piston base material, i.e. it extends up to the piston surface, this occurring however only in certain segments and not along the entire piston periphery. In the other segments, the insert lies beneath the piston surface and is thus covered by piston base material. To the extent that the insert is exposed on the piston end face, it is provided with an edge zone covering the depth of the self-contraction gap.

Description

Die Erfindung betrifft einen Kolben aus Leichtmetall für Brennkraftmaschinen mit einer im Vollmaterial der Kolbenkrone angeordneten, die Wärmedehnung des Kolben steuernden, in sich geschlossenen, hülsenförmigen Einlage aus einem Metall von geringerer Wärmeausdehnung als das Kolbengrundmaterial, welche Einlage sich über den gesamten Kolbenumfangswinkel von 360° erstreckt und mindestens einen Rand oder eine Seite hat, der oder die an die dem Feuerraum und/oder Feuersteg zugewandten äußeren Kolbenoberflächen heranreicht und an diesen Kolbenoberflächen vom Kolbenmaterial freigelegt ist, wobei an der der Kolbenachse zugewandten Innenseite der Einlage das Kolbenmaterial unter Bildung eines Spaltes von der Einlage freigeschrumpft ist. Dieses Freischrumpfen erfolgt beim Abkühlen nach dem Eingießen der Einlage in das Kolbengrundmaterial aufgrund dessen größeren Wärmedehnungskoeffizienten. Dabei hat sich das auf der Außenseite der Einlage befindliche Kolbengrundmaterial auf die Einlage aufgeschrumpft, wodurch diese eine Zugvorspannung erhalten hat. Da die während des Eingießens der Regeleinlage in den Kolbenschaft in diesem aufgetretenen Temperaturen während des Motorbetriebes nicht wieder erreicht werden, geht diese Schrumpfung während des Motorbetriebes nur zum Teil zurück, wodurch sich der bei Abkühlung des frisch gegossenen Kolbens durch Schrumpfung entstandene Spalt an der Innenseite der Regeleinlage nicht völlig zurückbildet.The invention relates to a piston made of light metal for internal combustion engines with a self-contained, sleeve-shaped insert made of a metal of lower thermal expansion than the piston base material which is arranged in the solid material of the piston crown and controls the thermal expansion of the piston, the insert extending over the entire piston circumferential angle of 360 ° and has at least one edge or a side that reaches the outer piston surfaces facing the combustion chamber and / or top land and is exposed on these piston surfaces by the piston material, the piston material on the inside of the insert facing the piston axis, forming a gap from the Insert has shrunk. This shrinking occurs during cooling after the insert has been poured into the piston base material due to its greater coefficient of thermal expansion. The piston base material located on the outside of the insert has shrunk onto the insert, as a result of which the latter has been subjected to a tensile prestress. Since the temperatures that occurred during the pouring of the control insert into the piston skirt cannot be reached again during engine operation, this shrinkage only partially decreases during engine operation, as a result of which the gap formed on the inside of the piston when the freshly cast piston cools due to shrinkage Rule deposit not fully reversed.

Ein Kolben der vorgenannten Gattung mit einer in der Kolbenkrone angeordneten Regeleinlage, die mindestens einen Rand oder eine Seite hat, der oder die an die dem Feuerraum und/oder Feuersteg zugewandten äußeren Kolbenoberflächen heranreicht, ist bereits bekannt (DE-C 630 440). Durch dieses Freiliegen der Regeleinlage an deren Seiten oder Rändern ergeben sich jedoch bei diesem bekannten Kolben an der Kolbenkrone Probleme bezüglich der Dauerwechselfestigkeit des an der Außenseite der Regeleinlage befindlichen relativ dünnen schalenförmigen äußeren Teils der Kolbenkrone, wobei es beim Motorbetrieb zum Abspringen dieses Teils und eventuell sogar der Regeleinlage kommen kann. Au- ßerdem kann in den an der einen Seite der Regeleinlage gegebenen und auch beim Motorbetrieb verbleibenden, durch die Freischrumpfung entstandenen Spalt kann ÖI eindringen, das dort bei den hohen Verbrennungstemperaturen verkokt und sich als Ölkohle ablagert, wodurch der Spalt nach und nach zugesetzt und die Regelwirkung dabei mehr und mehr eingeschränkt bzw. letztlich verhindert wird.A piston of the aforementioned type with a control insert arranged in the piston crown, which has at least one edge or a side which or which reaches the outer piston surfaces facing the combustion chamber and / or top land, is already known (DE-C 630 440). This exposure of the control insert on the sides or edges of this known piston on the piston crown, however, gives rise to problems with regard to the fatigue strength of the relatively thin, shell-shaped outer part of the piston crown located on the outside of the control insert, with the engine operating to cause this part to come off and possibly even the regular deposit can come. In addition, oil can penetrate into the gap created on one side of the control insert and also remains during engine operation due to the shrinking, which cokes there at the high combustion temperatures and is deposited as oil carbon, whereby the gap is gradually added and the Control effect is more and more restricted or ultimately prevented.

Ferner ist ein Kolben mit einer im Vollmaterial der Kolbenkrone angeordneten hülsenförmigen Einlage bekannt, welche sich, wie diejenige beim vorgenannten bekannten Kolben, über den gesamten Kolbenumfangswinkel von 360° erstreckt und einen freiliegenden Rand oder eine freiliegende Seite hat, die jedoch nicht als Regeleinlage dient sondern dazu, eine Hitzereflektion und bzw. oder eine Hitzeableitung von hitzegefährdeten Stellen zu bewirken, um an diesen Stellen die Temperatur zu senken (GB-A 530 570).Furthermore, a piston is known with a sleeve-shaped insert arranged in the solid material of the piston crown, which, like that in the aforementioned known piston, extends over the entire piston circumferential angle of 360 ° and has an exposed edge or an exposed side, which, however, does not serve as a control insert but instead to cause heat reflection and / or heat dissipation from heat-sensitive points in order to lower the temperature at these points (GB-A 530 570).

Außerdem sind Kolben mit im Bereich des Kolbenschaftes angeordneten Regeleinlagen bekannt, die sich ebenfalls über den gesamten Kolbenumfang erstrecken und an mindestens einem Rand oder einer Seite von Kolbenmaterial des Kolbenschaftes freigelegt sind (DE-B 1 073 257). Auch dort sind die gleichen Probleme wie bei den Kolben mit im Kolbenkopf angeordneten Einlagen gegeben, nämlich die Gefahr des Abspringens der an der Außenseite der Einlage befindlichen Kolbenteile und eventuell sogar der Einlage sowie des sich Zusetzens des durch Freischrumpfung gebildeten Spaltes durch verkokendes Öl.In addition, pistons with control inserts arranged in the region of the piston skirt are known, which likewise extend over the entire piston circumference and are exposed on at least one edge or one side of piston material of the piston skirt (DE-B 1 073 257). There, too, there are the same problems as with pistons with inserts arranged in the piston head, namely the risk of the piston parts located on the outside of the insert jumping off and possibly even the insert, and of the gap formed by shrinking free from coking oil.

Gegenüber diesem vorbekannten Stand der Technik liegt der Erfindung die Aufgabe zugrunde, bei einem Kolben der eingangs genannten Gattung eine örtlich begrenzte, also nur in bestimmten Segmenten des Kolbenkopfes eintretende Regelung zu gewährleisten und gleichzeitig eine feste Verankerung der Regeleinlage im Kolbenmaterial zu gewährleisten, um ein Wegschleudern der Einlage oder von Teilen des Kolbenkopfes zu verhindern. Außerdem soll das Zusetzen des Freischrumpfspaltes mit verkokender Ölkohle verhindert werden. Diese Aufgabe wird erfindungsgemäße dadurch gelöst, daß der Rand oder die Seite der Einlage nur in bestimmten Segmentenbereichen des Kolbens freigelegt ist, in den anderen Segmentenbereichen jedoch unter der äußeren Kolbenoberfläche liegt, d.h. vom Kolbengrundmaterial vollständig überdeckt und in diesem formschlüssig verankert ist und daß ein zum Feuerraum oder Feuersteg hin offener Freischrumpfspalt dadurch nicht gegeben ist, daß entweder die Tiefe dieses Freischrumpfspaltes vom Kolbengrundmaterial überdeckt ist, oder die Einlage in an der Kolbenstirnfläche freigelegten Bereichen mit einer zur Kolbenachse gerichteten, die Tiefe des Freischrumpfspaltes abdeckenden Abkantung versehen ist.Compared to this known prior art, the object of the invention is to ensure a locally limited control, that is to say only occurring in certain segments of the piston head, in a piston of the type mentioned above and, at the same time, to ensure that the control insert is firmly anchored in the piston material in order to prevent it from being flung away to prevent the insert or parts of the piston head. In addition, the clogging of the shrink gap with coking oil coal should be prevented. This object is achieved according to the invention in that the edge or the side of the insert is only exposed in certain segment areas of the piston, but in the other segment areas lies below the outer piston surface, i.e. completely covered by the piston base material and anchored in it in a form-fitting manner and that a free shrink gap open to the combustion chamber or top land does not exist because either the depth of this free shrink gap is covered by the piston base material or the insert in areas exposed on the piston face with an area facing the piston axis , the depth of the free shrink gap covering bevel.

Durch das Freiliegen der Regeleinlage nur in bestimmten Segmentbereichen wird eine örtlich begrenzte und nur in diesen Segmentbereichen der Kolbenkrone wirksame gezielte Regelung erreicht. Hierdurch erhält die Kolbenkrone eine außerordentlich hohe Elastizität, wodurch ihr Anschlagen und der Zylinderwand in ein elastisch-federndes Anlaufen umgewandelt wird und die Gefahr eines Kolbenfressens weitgehend vermindert wird.By exposing the control insert only in certain segment areas, a locally limited control that is effective only in these segment areas of the piston crown is achieved. This gives the piston crown an extraordinarily high elasticity, which means that its abutment and the cylinder wall are converted into an elastic, spring-like start and the risk of piston seizure is largely reduced.

Die erfindungsgemäße Einlage kann z.B. mit ihrem einen unteren Rand oder ihrer unteren Seite an die Kolbenseitenwand oder an eine Kolbenringnut heran freigelegt sein. Es kann auch zweckmäßig sein, daß die Einlage im Querschnitt eine Abknickung oder Rundung besitzt und mit dieser oder mit ihrer gesamten Außenseite an der Kolbenseitenwand liegt, also an dieser freigelegt ist. Auch ist es möglich, der Ringnut mit einem der freigeschnittenen Enden der Regeleinlage zumindest eine teilweise Armierung zu geben.The insert according to the invention can e.g. be exposed with its one lower edge or its lower side to the piston side wall or to a piston ring groove. It may also be expedient for the insert to have a kink or rounding in cross-section and to lie with it or with its entire outside on the piston side wall, that is to say it is exposed on the latter. It is also possible to provide the annular groove with at least a partial reinforcement with one of the cut-off ends of the control insert.

Weitere vorteilhafte Ausgestaltungen des erfindungsgemäßen Kolbens ergeben sich aus den Patentansprüchen und aus der Zeichnung.

  • Fig. 1 zeigt eine erste Ausführungsform des erfindungsgemäßen Kolbens im Axialschnitt durch den Kolben, wobei die linke Zeichnungshälfte einen Schnitt darstellt, der sich senkrecht zu demjenigen der rechten Zeichnungshälfte erstreckt.
  • Fig. 2 zeigt einen Querschnitt durch die Ausführungsform gemäß Fig. 1 nach Linie 11-11 in Fig. 1.
  • Fig. 3 zeigt eine vergrößerte Schrägansicht der Regeleinlage bei dieser Ausführungsform gemäß Fig. 1 und 2.
  • Fig. 4 zeigt eine zweite Ausführungsform in gleicher Darstellungsweise wie Fig. 1.
  • Fig. 5 ist ein Querschnitt nach Linie V-V in Fig. 4.
  • Fig. 6 zeigt eine dritte Ausführungsform in gleicher Darstellungsweise wie Fig. 1.
  • Fig. 7 ist ein Querschnitt nach Linie VII-VII in Fig. 6.
  • Fig. 8 zeigt eine vierte Ausführungsform in gleicher Darstellungsweise wie Fig. 1.
  • Fig. 9 ist ein Querschnitt nach Linie IX-IX in Fig. 8.
  • Fig. 10 zeigt eine fünfte Ausführungsform in gleicher Darstellungsweise wie Fig. 1.
  • Fig. 11 ist ein Querschnitt nach Linie XI-XI in Fig. 10.
  • Fig. 12 zeigt eine sechste Ausführungsform in gleicher Darstellungsweise wie Fig. 1.
  • Fig. 13 ist ein Querschnitt nach Linie XIII-XIII in Fig. 12.
  • Fig. 14 zeigt eine siebte Ausführungsform in gleicher Darstellungsweise wie Fig. 1.
  • Fig. 15 ist ein Querschnitt nach Linie XV-XV in Fig. 14.
  • Fig. 16 zeigt eine achte Ausführungsform in gleicher Darstellungsweise wie Fig. 1.
  • Fig. 17 ist ein Querschnitt nach Linie XVII-XVII in Fig. 16.
  • Fig. 18 zeigt eine neunte Ausführungsform in gleicher Darstellungsweise wie Fig. 1.
  • Fig. 19 zeigt einen Querschnitt nach Linie XIX-XIX in Fig. 18,
  • Fig. 20 zeigt eine zehnte Ausführungsform in gleicher Darstellungsweise wie Fig. 1,
  • Fig. 21 ist eine Draufsicht auf die Kolbenstirnfläche dieser Ausführungsform,
  • Fig. 22 ist eine vergrößerte Schrägansicht der Einlage gemäß Fig. 20 und 21,
  • Fig. 23 zeigt eine elfte Ausführungsform in gleicher Darstellungsweise wie Fig. 1,
  • Fig. 24 ist eine Draufsicht auf die Kolbenstirnfläche dieser Ausführungsform,.
  • Fig. 25 zeigt eine zwölfte Ausführungsform in gleicher Darstellung wie Fig. 1,
  • Fig. 26 ist ein Querschnitt nach Linie XXVI-XXVI in Fig. 25,
  • Fig. 27 ist eine dreizehnte Ausführungsform in gleicher Darstellung wie Fig. 1,
  • Fig. 28 zeigt einen Querschnitt nach Linie XXVIII-XXVIII in Fig. 27.
Further advantageous embodiments of the piston according to the invention result from the patent claims and from the drawing.
  • Fig. 1 shows a first embodiment of the piston according to the invention in axial section through the piston, the left half of the drawing represents a section that extends perpendicular to that of the right half of the drawing.
  • FIG. 2 shows a cross section through the embodiment according to FIG. 1 along line 11-11 in FIG. 1.
  • 3 shows an enlarged oblique view of the control insert in this embodiment according to FIGS. 1 and 2.
  • FIG. 4 shows a second embodiment in the same representation as FIG. 1.
  • FIG. 5 is a cross section along line VV in FIG. 4.
  • FIG. 6 shows a third embodiment in the same representation as FIG. 1.
  • FIG. 7 is a cross section along line VII-VII in FIG. 6.
  • FIG. 8 shows a fourth embodiment in the same representation as FIG. 1.
  • Fig. 9 is a cross section along line IX-IX in Fig. 8.
  • FIG. 10 shows a fifth embodiment in the same representation as FIG. 1.
  • FIG. 11 is a cross section along line XI-XI in FIG. 10.
  • FIG. 12 shows a sixth embodiment in the same representation as FIG. 1.
  • FIG. 13 is a cross section along line XIII-XIII in FIG. 12.
  • FIG. 14 shows a seventh embodiment in the same representation as FIG. 1.
  • 15 is a cross section along line XV-XV in FIG. 14.
  • FIG. 16 shows an eighth embodiment in the same representation as FIG. 1.
  • Fig. 17 is a cross section along line XVII-XVII in Fig. 16.
  • FIG. 18 shows a ninth embodiment in the same representation as FIG. 1.
  • 19 shows a cross section along line XIX-XIX in FIG. 18,
  • 20 shows a tenth embodiment in the same representation as FIG. 1,
  • 21 is a plan view of the piston face of this embodiment;
  • 22 is an enlarged oblique view of the insert of FIGS. 20 and 21,
  • 23 shows an eleventh embodiment in the same representation as FIG. 1,
  • 24 is a plan view of the piston face of this embodiment.
  • 25 shows a twelfth embodiment in the same representation as FIG. 1,
  • Fig. 26 is a cross section along line XXVI-XXVI in Fig. 25,
  • 27 is a thirteenth embodiment in the same representation as FIG. 1,
  • FIG. 28 shows a cross section along line XXVIII-XXVIII in FIG. 27.

In den Zeichnungen ist in sämtlichen Ausführungsbeispielen der Kolben mit seinem Grundmaterial mit Bezugsziffer 1, die obere Ringnut mit Bezugsziffer 2, das Bolzenauge mit Bezugsziffer 3 und die Bolzenbohrung mit Bezugsziffer 4 versehen. In allen Ausführungsbeispielen ist die Kolbenstirnfläche 5 zur Bildung eines zentralen Brennraumes 6 vertieft. Die Kolbenseitenwand hat die Bezugsziffer 8. In den Zeichnungen ist jeweils der Freischrumpfspalt, der sich unmittelbar an der der Kolbenhochachse 13 zugewandten Innenseite der Regeleinlage befindet, nicht dargestellt.In the drawings, the piston is provided with its base material with reference number 1, the upper annular groove with reference number 2, the bolt eye with reference number 3 and the pin bore with reference number 4 in all exemplary embodiments. In all exemplary embodiments, the piston end face 5 is recessed to form a central combustion chamber 6. The piston side wall has the reference number 8. The free shrink gap, which is located directly on the inside of the control insert facing the piston vertical axis 13, is not shown in the drawings.

Bei der in Fig. 1-3 dargestellten Ausführungsform erstreckt sich die Einlage 7 geringfügig innerhalb (unter) der Kolbenseitenwand 8 ringförmig über den gesamten Kolbenumfang, wobei ihre Ringform an zwei einander gegenüberliegenden Segmentbereichen 9 begradigt ist, so daß sich in diesen Segmentbereichen des Kolbenkopfes die Einlage in etwas größeren Abstand von der Kolbenseitenwand 8 befindet als in ihren kreisrunden Segmentbereichen 10. In ihren kreisrunden Segmentbereichen besitzt diese Einlage im Hülsenquerschnitt L-Form, wobei der eine Querschnittsschenkel 11 sich an der Kolbenstirnfläche 5 befindet und den an der Innenseite der Einlage entstandenen nicht gezeichneten Freischrumpfspalt abdeckt. Die hülsenförmige Einlage ist also mit diesem Schenkel 11 an der Kolbenstirnfläche freigelegt. Mit dem Rand ihres anderen Schenkels 12 ist diese Einlage im genannten Segmentbereich an der Kolbenringnut 2 freigelegt.In the embodiment shown in Fig. 1-3, the insert 7 extends slightly inside (under) the piston side wall 8 in a ring over the entire piston circumference, its ring shape being straightened on two opposite segment areas 9, so that in these segment areas of the piston head The insert is located at a somewhat greater distance from the piston side wall 8 than in its circular segment regions 10. In its circular segment regions, this insert has an L-shaped sleeve cross section, one cross-sectional leg 11 being located on the piston end face 5 and the one that did not arise on the inside of the insert drawn shrink gap covers. The sleeve-shaped insert is thus exposed with this leg 11 on the piston end face. With the edge of its other leg 12, this insert is exposed in the said segment area on the piston ring groove 2.

In ihren beiden anderen einander gegenüberliegenden begradigten Segmentbereichen 9 ist die Einlage in ihrem Querschnitt von ihrer sonstigen L-Form auf einen relativ kleinen Teil des L-Schenkels 12 reduziert, und zwar derart, daß dieser Segmentbereich 9 allseits formschlüssig im Kolbengrundmaterial 1 eingebettet und verankert ist.In its two other opposite, straightened segment areas 9, the cross section of the insert is reduced from its other L-shape to a relatively small part of the L-leg 12, in such a way that this segment area 9 is embedded and anchored on all sides in the piston base material 1 .

Bei dem in Fig. 1 und 2 dargestellten Ausführungsbeispiel befinden sich die begradigten und kleinen Querschnitt besitzenden Segmentbereiche 9 der Einlage 7 über den Bolzenaugen 3, während die L-förmigen Querschnitt aufweisenden Bereiche 10 der Einlage in bezug auf die Kolbenhochachse 13 um 90° dazu im Kolbenquerschnitt versetzt sind, so daß sie seitlich über den Bolzenaugen 3 liegen.In the embodiment shown in FIGS. 1 and 2, the straightened and small cross-sectional segment regions 9 of the insert 7 are located above the bolt eyes 3, while the L-shaped cross-sectional regions 10 of the insert are 90 ° with respect to the piston vertical axis 13 Piston cross-section are offset so that they are laterally above the pin eyes 3.

Bei dem in Fig. 4 und 5 dargestellten Ausführungsbeispiel hat die Einlage 14 die gleiche Form wie die Einlage 7 beim Ausführungsbeispiel gemäß Fig. 1 und 2. Sie ist auch in gleicher Weise wie bei diesem Ausführungsbeispiel im Kolben angeordnet mit der Ausnahme, daß sich die Segmentbereiche 15 mit größerem L-förmigen Querschnitt über den Bolzenaugen 3 befinden, während die den reduzierten Querschnitt aufweisenden begradigten Segmentbereiche 16 in bezug auf die Kolbenhochachse um 90° dazu im Kolbenquerschnitt versetzt seitlich über den Bolzenaugen 3 liegen.In the embodiment shown in FIGS. 4 and 5, the insert 14 has the same shape as the insert 7 in the embodiment according to FIGS. 1 and 2. It is also arranged in the piston in the same way as in this embodiment, with the exception that the Segment areas 15 with a larger L-shaped cross section are located above the pin eyes 3, while the straightened segment areas 16 with the reduced cross section are offset laterally above the pin eyes 3 with respect to the piston vertical axis by 90 ° in the piston cross section.

Das Ausführungsbeispiel gemäß Fig. 6 und 7 besitzt eine Einlage 17, die in ihren kreisförmigen, sich über den Bolzenaugen 3 befindlichen Segmentbereichen 8 U-förmigen Querschnitt hat, der mit seinem oberen den Freischrumpfspalt abdeckenden Schenkel an der Kolbenstirnfläche 5 und mit seinem unteren Schenkel an der oberen Ringnut 2 freigelegt ist. In seinen begradigten Segmentbereichen 19 ist die Einlage 17 im Querschnitt auf den unteren Teil des U-Steges beschränkt.The exemplary embodiment according to FIGS. 6 and 7 has an insert 17 which, in its circular segment regions 8 located above the bolt eyes 3, has a U-shaped cross section, the upper leg covering the free shrink gap on the piston end face 5 and the lower leg the upper ring groove 2 is exposed. In its straightened segment areas 19, the insert 17 is limited in cross section to the lower part of the U-web.

Das Ausführungsbeispiel gemäß Fig. 8 und 9 unterscheidet sich von demjenigen gemäß Fig. 6 und 7 nur dadurch, daß die Einlage 20 sich mit ihren begradigten Segmentbereichen 21 über den Bolzenaugen 3 und mit ihren dazwischen befindlichen Segmentbereichen 22 seitlich oberhalb der Bolzenaugen befindet.The embodiment according to FIGS. 8 and 9 differs from that according to FIGS. 6 and 7 only in that the insert 20 with its straightened segment areas 21 is above the bolt eyes 3 and with its segment areas 22 located therebetween laterally above the bolt eyes.

Auch bei dem Ausführungsbeispiel gemäß Fig. 10 und 11 erstreckt sich die Einlage 23 ringförmig in geringem Abstand innerhalb der Kolbenseitenwand 8 um den Kolbenumfang herum und besitzt zwei kreisrunde Segmentbereiche 24 und zwei dazwischen liegende begradigte Segmentbereiche 25. In den kreisrunden Segmentbereichen hat die Einlage 23 größeren Querschnitt als in ihren begradigten Segmentbereichen 25, wobei sie in ihrem oberen Querschnittsbereich in Richtung der Kolbenseitenwand 8 abgebogen und an dieser Kolbenseitenwand freigelegt ist. Mit ihrem unteren Rand ist sie in diesen Segmentbereichen in der Kolbenringnut 2 freigelegt. In ihren begradigten Segmentbereichen 25 hat diese Einlage 23 einen verkleinerten Querschnitt, der dem unterhalb der vorgenannten Abbiegung im kreisrunden Segmentbereich 24 befindlichen Querschnittsteil der Einlage entspricht.10 and 11, the insert 23 extends in a ring at a short distance within the piston side wall 8 around the circumference of the piston and has two circular segment areas 24 and two straightened segment areas 25 therebetween. The insert 23 has larger ones in the circular segment areas Cross-section than in its straightened segment regions 25, wherein in its upper cross-sectional region it is bent in the direction of the piston side wall 8 and is exposed on this piston side wall. With its lower edge, it is exposed in the piston ring groove 2 in these segment areas. In its straightened segment regions 25, this insert 23 has a reduced cross-section, which corresponds to the cross-sectional part of the insert located below the aforementioned bend in the circular segment region 24.

Die Einlage ist in allen ihren Segmentbereichen unterhalb der Kolbenstirnfläche 5 im Kolbengrundmaterial 1 gelagert und daher von diesem überdeckt. Ein zum Feuerraum hin offener Freischrumpfspalt ist daher auch bei dieser Ausführungsform nicht gegeben. In ihren begradigten Segmentbereichen 25 liegt die Einlage vom Kolbengrundmaterial vollständig umgeben innerhalb der Kolbenseitenwand und ist auch nicht an einer Kolbenringnut freigelegt.The insert is supported in all of its segment areas below the piston face 5 in the piston base material 1 and is therefore covered by this. A free shrink gap open to the combustion chamber is therefore not provided in this embodiment either. In its straightened segment regions 25, the insert lies completely surrounded by the piston base material within the piston side wall and is also not exposed on a piston ring groove.

Bei diesem Ausführungsbeispiel befinden sich die allseitig im Kolbengrundmaterial 1 eingebetteten begradigten Segmentbereiche 25 der Einlage 23 oberhalb der Bolzenaugen 3, während die freigelegten Segmentbereiche 24 in bezug auf die Kolbenhochachse 13 um 90° dazu im Kolbenquerschnitt versetzt sind.In this exemplary embodiment, the straightened segment regions 25 of the insert 23 embedded on all sides in the piston base material 1 are located above the bolt eyes 3, while the exposed segment regions 24 are offset by 90 ° with respect to the piston vertical axis 13 in the piston cross section.

Bei dem in Fig. 12 und 13 dargestellten Ausführungsbeispiel hat die Einlage 26 gleiche Form wie die Einlage 23 beim Ausführungsbeispiel gemäß Fig. 10 und 11. Sie ist jedöch so in der Kolbenkrone angeordnet, daß sich ihre freigelegten kreisförmigen Segmentbereiche 27 über den Bolzenaugen 3 befinden.In the embodiment shown in FIGS. 12 and 13, the insert 26 has the same shape as the insert 23 in the embodiment according to FIGS. 10 and 11. However, it is arranged in the piston crown in such a way that its exposed circular segment regions 27 are located above the bolt eyes 3 .

Das Ausführungsbeispiel gemäß Fig. 14 und 15 unterscheidet sich von demjenigen gemäß Fig. 10 und 11 nur dadurch, daß die Einlage 28 in ihren ringförmigen Segmentbereichen 29 noch einen unterhalb der oberen Kolbenringnut 2 befindlichen, diese Nut armierenden Querschnittsteil 30 besitzt, der ebenso wie der obere Querschnittsteil 31 mit den begradigten Segmentbereichen 32 verbunden ist.The exemplary embodiment according to FIGS. 14 and 15 differs from that according to FIGS. 10 and 11 only in that the insert 28 in its annular segment regions 29 still has a cross-sectional part 30 located below the upper piston ring groove 2 and reinforcing this groove, which, like that Upper cross-sectional part 31 is connected to the straightened segment areas 32.

Bei diesem Ausführungsbeispiel befinden sich die ringförmigen Segmentbereiche 29 der Einlage 28 mit ihrem vollen Querschnitt seitlich oberhalb der Bolzenaugen 3, während die begradigten kleinen Querschnitt besitzenden Segmentbereiche 32 über den Bolzenaugen 3 liegen. Es ist aber auch eine umgekehrte Lage der verschiedenartigen Segmentbereiche 28,32 möglich.In this exemplary embodiment, the ring-shaped segment regions 29 of the insert 28 with their full cross-section are located laterally above the bolt eyes 3, while the straightened small cross-section segment regions 32 lie above the bolt eyes 3. However, an inverted position of the different segment areas 28, 32 is also possible.

Auch beim Ausführungsbeispiel gemäß Fig. 16 und 17 ist die Regeleinlage 33 nicht an der Kolbenstirnfläche 5 sondern an der Kolbenseitenwand 8 freigelegt, wodurch eine Abdeckung des Freischrumpfspaltes gegenüber dem Feuerraum durch das Kolbengrundmaterial 1 gegeben ist. Die Einlage ist in zwei einander gegenüberliegenden, sich über den Bolzenaugen 3 befindlichen Segmentbereichen 34 im Querschnitt U-förmig ausgebildet, wobei die Ränder der U-Schenkel an der Kolbenseitenwand 8 freigelegt sind. Der untere U-Schenkel ist auch an der oberen Kolbenringnut 2 freigelegt.16 and 17, the control insert 33 is not exposed on the piston end face 5 but on the piston side wall 8, so that the free shrink gap is covered by the piston base material 1 with respect to the combustion chamber. The insert is U-shaped in cross-section in two opposite segment areas 34 located above the bolt eyes 3, the edges of the U-legs being exposed on the piston side wall 8. The lower U-leg is also exposed on the upper piston ring groove 2.

In den beiden anderen Segmentbereichen 35, die sich seitlich oberhalb der Bolzenaugen 3 befinden, ist die Einlage 33 in ihrem Querschnitt etwa auf die untere Querschnittshälfte der beiden anderen Segmentbereichen 34 reduziert, so daß die Einlage in diesen Segmentbereichen nur mit ihrem unteren Rand in der Kolbenringnut 2 und an der Kolbenseitenwand 8 freigelegt ist.In the other two segment areas 35, which are located laterally above the bolt eyes 3, the insert 33 is reduced in its cross section approximately to the lower cross-sectional half of the other two segment areas 34, so that the insert in these segment areas only with its lower edge in the piston ring groove 2 and is exposed on the piston side wall 8.

Die Ausführungsform gemäß Fig. 18 und 19 unterscheidet sich nur dadurch von derjenigen der Fig. 16 und 17, daß die Einlage 36 mit ihrem U-förmigen Querschnitt besitzenden Segmentbereich 37 seitlich oberhalb der Bolzenaugen 3 und mit ihrem etwa auf die untere Hälfte dieses U-Querschnitts reduzierten Querschnitt besitzenden Segmentbereichen 38 sich über den Bolzenaugen 3 befindet.The embodiment according to FIGS. 18 and 19 differs only from that of FIGS. 16 and 17 in that the insert 36 with its U-shaped cross-section has segment region 37 laterally above the bolt eyes 3 and with its approximately on the lower half of this U- Cross-section reduced cross-section segment areas 38 is located above the bolt eyes 3.

Das Ausführungsbeispiel gemäß Fig. 20 bis 22 unterscheidet sich von demjenigen gemäß Fig. 16 und 17 nur dadurch, daß dort die Einlage 39 in-den beiden über den Bolzenaugen 3 befindlichen Segmentbereichen S-Form hat, wobei der obere S-Schenkel 40 an der Kolbenstirnfläche 5 freigelegt ist und der untere S-Schenkel an der Kolbenseitenwand 8 und in der oberen Ringnut 2. In ihren beiden anderen Segmentbereichen 41, die sich seitlich oberhalb der Bolzenaugen 3 befinden, ist die Einlage 39 im Querschnitt auf die untere Hälfte des in den vorgenannten Segmentbereichen gegebenen S-förmigen Querschnitts reduziert, so daß dort die Einlage nur an der Kölbenseitenwand 8 und in der oberen Ringnut 2 freigelegt ist. Der Freischrumpfspalt ist somit in den beiden Segmentbereichen mit S-Querschnitt durch den oberen S-Schenkel 40 und in den beiden anderen Segmentbereichen 41 durch das Kolbengrundmaterial 1 überdeckt.The exemplary embodiment according to FIGS. 20 to 22 differs from that according to FIGS. 16 and 17 only in that the insert 39 there has an S-shape in the two segment areas located above the bolt eyes 3, the upper S-leg 40 on the Piston end face 5 is exposed and the lower S-leg on the piston side wall 8 and in the upper annular groove 2. In its two other segment areas 41, which are located laterally above the pin eyes 3, the insert 39 is in cross-section on the lower half of the in the the aforementioned segment areas given S-shaped cross-section reduced, so that there the insert is only exposed on the Cologne side wall 8 and in the upper annular groove 2. The free shrink gap is thus covered in the two segment areas with an S cross section by the upper S leg 40 and in the two other segment areas 41 by the piston base material 1.

Das Ausführungsbeispiel gemäß Fig. 23 und 24 besitzt eine gleichgestaltete Einlage 42 wie das Ausführungsbeispiel gemäß Fig. 20 und 21, jedoch ist diese Einlage mit ihren vollen S-Querschnitt besitzenden Segmentbereichen 43 seitlich über den Bolzenaugen 3 angeordnet, während ihre reduzierten Querschnitt besitzenden Segmentbereiche 44 sich direkt über den Bolzenaugen 3 befinden.The exemplary embodiment according to FIGS. 23 and 24 has an insert 42 of the same design as the exemplary embodiment according to FIGS. 20 and 21, but this insert, with its segment areas 43 having a full S cross section, is arranged laterally above the bolt eyes 3, while its reduced cross-section segment regions 44 are located directly above the bolt eyes 3.

Fig. 25 und 26 zeigen ein Ausführungsbeispiel, bei welchem die Einlage 45 in den beiden seitlich oberhalb der Bolzenaugen 3 liegenden Segmentbereichen 46 U-förmigen Querschnitt hat und mit ihrer gesamten Außenseite an der Kolbenseitenwand 8 freigelegt ist, wobei ihr oberer U-Schenkel an der Kolbenstirnfläche und ihr unterer U-Schenkel an der oberen Ringnut 2 freigelegt sind.25 and 26 show an embodiment in which the insert 45 has a U-shaped cross-section in the two segment regions 46 lying laterally above the bolt eyes 3 and is exposed with its entire outside on the piston side wall 8, with its upper U-leg on the Piston face and its lower U-leg are exposed on the upper annular groove 2.

Ihre über den Bolzenaugen 3 befindlichen Segmentbereiche 47 liegen in einem gewissen Abstand innerhalb der Kolbenseitenwand 8. In diesen Segmentbereichen hat die Einlage rechteckförmigen Querschnitt von geringeren Abmessungen als in ihren anderen Segmentbereichen 46, wobei sie allseitig vom Kolbengrundmaterial 1 umgeben und damit in diesem fest verankert ist.Its segment regions 47 located above the bolt eyes 3 lie at a certain distance within the piston side wall 8. In these segment regions, the insert has a rectangular cross section of smaller dimensions than in its other segment regions 46, all of them tig surrounded by the piston base material 1 and thus firmly anchored in this.

Die wesentliche angestrebte Wirkung dieser Art von Einlage beruht auf dem Freischrumpfen des an der Innenseite der Einlage befindlichen Kolbengrundmaterials. Die zweite Wirkung einer derartigen Regelhülse, nämlich die an der Außenseite der Regeleinlage befindliche Schicht des Kolbengrundmaterials durch Aufschrumpfen auf die Einlage bei niedrigeren Temperaturen unter Zugspannung zu setzen und damit einen Teil ihrer Ausdehnung bei anschließender Erwärmung im Motorbetrieb unwirksam zu machen, wird bei der letztgenannten Ausführungsform dahingehend verbessert, daß die außenliegende Schicht des Kolbengrundkörpers segmentartig völlig entfällt und im Hinblick auf das Spiel zwischen Kolbenkrone und Zylinderwand im Motor dort nur noch der geringere Ausdehnungskoeffizient des Materials der Regeleinlage wirksam wird.The main desired effect of this type of insert is based on the shrinking of the piston base material located on the inside of the insert. The second effect of such a regulating sleeve, namely placing the piston base material layer on the outside of the regulating insert by shrinking onto the insert at lower temperatures under tensile stress and thus rendering some of its expansion ineffective during subsequent engine operation becomes ineffective in the latter embodiment improved to the effect that the outer layer of the piston base body is completely eliminated in segments and only the lower coefficient of expansion of the material of the control insert is effective there with regard to the play between the piston crown and the cylinder wall in the engine.

Bei dem Ausführungsbeispiel gemäß Fig. 27 und 28 besitzt die Regeleinlage 48 zwei kreisförmig gebogene Segmentbereiche 49, in welchen die Einlage rechteckigen Querschnitt hat und mit ihrer gesamten Außenseite an der Kolbenaußenfläche 8 freigelegt ist. Ferner besitzt sie zwei über den Bolzenaugen 3 befindliche Segmentbereiche 50, ebenfalls von rechteckigem Querschnitt, die sich geradlinig innerhalb der Kolbenseitenwand 8 erstrecken und allseitig vom Kolbengrundkörper umgeben und damit in diesem fest verankert sind.In the exemplary embodiment according to FIGS. 27 and 28, the control insert 48 has two circularly curved segment regions 49, in which the insert has a rectangular cross section and its entire outside is exposed on the piston outer surface 8. Furthermore, it has two segment areas 50, also of rectangular cross-section, located above the bolt eyes 3, which extend in a straight line within the piston side wall 8 and are surrounded on all sides by the piston base body and are thus firmly anchored in the latter.

Die obere Ringnut 2 ist in dem gezeigten Ausführungsbeispiel mit einer zusätzlichen im Ringquerschnitt U-förmigen Armierung 51 versehen, wie sie nach dem Stand der Technik insbesonders bei Kolben für Dieselmotoren üblich ist.In the exemplary embodiment shown, the upper annular groove 2 is provided with an additional reinforcement 51 with a U-shaped cross section, as is customary in the prior art, in particular for pistons for diesel engines.

Claims (21)

1. Piston made from light metal for internal combustion engines having a self-contained sleeve-shaped insert (7, 14, 17, 20, 23, 26, 28, 33, 36, 39, 42, 45, 48) which is disposed in the solid material of the piston top and controls the thermal expansion of the piston, said insert being made of a metal having a lower thermal expansion than the piston's basic material and extening over the entire angle at circumference of the piston of 360° and having at least one edge or side which extends as fas as the outer piston surfaces (2, 5, 8) facing the combustion chamber and/or combustion web and is exposed by the piston material at these piston surfaces (2, 5, 8), the piston material being shrunk clear of the insert and forming a gap on the inner side of the insert facing the piston exis (13), characterised in that the edge or side of the insert is exposed only in specific segmental regions (10, 15, 18, 22, 24, 27, 29, 34, 37, 40, 43, 45, 49) of the piston, being located in the other segmental regions below the outer piston surface (2, 5, 8), i.e. completely covered by the piston's basic material (1) and positively anchored therein, and that a shrunk-fred gap open towards the compustion chamber or web is eliminated in that either the depth of this shrunk-free gap is covered by the piston basic material or the insert is provided in exposed regions on the piston face (5) with a fold directed towards the piston axis (13) and covering the depth of the shrunk-free gap.
2. Piston according to claim 1, characterised in that the insert is exposed towards the piston side wall (8) (Fig. 10, 12, 14, 16, 18, 20, 25, 27, 28).
3. Piston according to claim 2, characterised in that the entire outer side of the sleeve-shaped insert is exposed in specific segments to the piston side wall (Fig. 25).
4. Piston according to claim 2, characterised in that the sleeve-shaped insert has in the sleeve cross-section a branch and is exposed by this to the piston side wall (8) (Fig. 10, 12, 14, 16, 18, 20, 22, 23).
5. Piston according to claim 1, characterised in that one edge of the sleeve-shaped insert is exposed towards the piston face (5) while its other ede is exposed towards the piston side wall (8).
6. Piston according to claim 1, characterised in that the lower edge of the sleeve-shaped insert is exposed to a piston ring groove (2) (Fig. 1, 4, 6, 8, 10, 12, 14, 16, 18, 20, 23, 25).
7. Piston according to claim 1, characterised in that the edge of the sleeve-shaped insert exposed towards the surface of the ring groove (2) is exposed over the entire periphery of the ring groove (Figs. 16 to 24).
8. Piston according to claim 1, characterised in that the sleeve-shaped insert is symmetrically shaped relative to the piston axis (13) in two sections which are perpendicular to one another and include the piston axis.
9. Piston according to claim 1, characterised in that the exposed segmental regions of the sleeve-shaped insert are disposed asymmetrically relative to the piston axis (13).
10. Piston according to claim 1, characterised in that the sleeve-shaped insert is exposed in a segment-like way only at a single point of the piston periphery.
11. Piston according to claim 1, characterised in that the sleeve-shaped insert is exposed in two opposite-lying segmental regions, between each of which it is located below the piston surface (5, 8).
12. Piston according to claim 11, characterised in that the segmental region of the sleeve-shaped insert located below the piston surface (5, 8) are located substantially above the bolt eyes (3).
13. Piston according to claim 12, characterised in that the cut-free segmental regions of the sleeve-shaped insert are located substantially above the bolt eyes (3).
14. Piston according to claim 11, characterised in that the opposing exposed segmental regions and the segmental regions located below the piston surface (5, 8) each extend over approximately 1/4 of the sleeve periphery of the insert.
15. Piston according to claim 1, characterised in that the sleeve-shaped insert has smaller sleeve cross-sectional dimensions in its segmental regions located below the surface (5, 8) of the piston than in its exposed segmental regions.
16. Piston according to claim 1, characterised in that the exposed segmental regions of the sleeve-shaped insert, compared to the segmental regions completely enclosed by the piston basic material (1), diverge in an axial and/or radial direction from a circular course.
17. Piston according to claim 1, characterised in that the sleeve-shaped insert extends approximately circularly in its exposed segmental regions and approximately rectilinearly in its segmental regions located below the piston surface.
18. Piston according to claim 1, characterised in that the sleeve-shaped insert in its exposed segmental regions has a ring cross-section shaped like an L, a U, an S or the like and in its non-exposed segmental regions part of the L-, U- or S-shape is not formed.
19. Piston according to claim 1, characterised in that the sleeve-shaped insert is formed from sheet steel.
20. Piston according to claim 1, characterised in that the sleeve-shaped insert is manufactured from a cast iron alloy.
21. Piston according to claim 1, characterised in that the surface of the sleeve-shaped insert is ribbed, e.g. in the shpae of a heneycomb.
EP86110453A 1985-07-31 1986-07-29 Light-weight metal piston Expired EP0210649B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT86110453T ATE48895T1 (en) 1985-07-31 1986-07-29 ALLOY PISTON.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19853527447 DE3527447A1 (en) 1985-07-31 1985-07-31 LIGHT METAL PISTON
DE3527447 1985-07-31

Publications (3)

Publication Number Publication Date
EP0210649A2 EP0210649A2 (en) 1987-02-04
EP0210649A3 EP0210649A3 (en) 1987-04-29
EP0210649B1 true EP0210649B1 (en) 1989-12-20

Family

ID=6277295

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86110453A Expired EP0210649B1 (en) 1985-07-31 1986-07-29 Light-weight metal piston

Country Status (7)

Country Link
US (1) US4754731A (en)
EP (1) EP0210649B1 (en)
JP (1) JPS6241953A (en)
KR (1) KR870001392A (en)
AT (1) ATE48895T1 (en)
BR (1) BR8603617A (en)
DE (2) DE3527447A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4110306A1 (en) * 1990-09-20 1992-03-26 Mahle Gmbh SUBMERSIBLE ALLOY PISTON FOR OTTO ENGINES
JP2000008948A (en) * 1998-04-21 2000-01-11 Nissan Motor Co Ltd Piston of internal combustion engine
DE19848649C5 (en) * 1998-10-22 2008-11-27 Peter Greiner Carbon piston for an internal combustion engine

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE630440C (en) * 1936-05-28 Elektronmetall G M B H Light metal pistons for internal combustion engines
GB407478A (en) * 1931-12-11 1934-03-22 Karl Friedrich Wagner Improvements in or relating to pistons for internal combustion engines
GB530570A (en) * 1939-06-09 1940-12-16 Frank Hunter Clayton Improvements in and relating to pistons for internal combustion engines and the like
CH346068A (en) * 1956-12-03 1960-04-30 Fonderie Tech De Vitry Sur Sei Internal combustion engine piston
US3094903A (en) * 1961-08-17 1963-06-25 Zollner Corp Piston head with heat dam or barrier
US3190273A (en) * 1964-01-03 1965-06-22 Continental Aviat & Eng Corp Piston for internal combustion engine
DE2441933C3 (en) * 1974-09-02 1980-08-14 Karl Schmidt Gmbh, 7107 Neckarsulm Unslotted light metal piston for highly loaded internal combustion engines

Also Published As

Publication number Publication date
KR870001392A (en) 1987-03-13
DE3667703D1 (en) 1990-01-25
BR8603617A (en) 1987-03-10
US4754731A (en) 1988-07-05
JPS6241953A (en) 1987-02-23
EP0210649A3 (en) 1987-04-29
EP0210649A2 (en) 1987-02-04
DE3527447A1 (en) 1987-02-12
ATE48895T1 (en) 1990-01-15

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