Mahle International Gmbh

Mahle Gmbh

Dieter Gabriel

Michael T Lapp

Wolfgang Rein

Luiz Perrone

Joachim Wagenblast

Ioan Stefan

Ralph Klein

Fabio Menotti

Volker Weisse

Steve Walker

Michael Ulrich

Leandro Menezes

Grace Zhao

Mike L Wilder

Rein Wolfgang

Piston for an internal combustion engine

A piston for an internal combustion engine is formed from an upper part connected to a lower part. The upper part has a combustion bowl, a top land, and a ring belt extending circumferentially around the piston upper part. The lower part contains pin bosses and a piston skirt. A circumferential cooling channel is formed by joining the upper and lower parts. There is an oil inlet formed in one piece with the piston lower part. The inlet has a lower extremity and an upper extremity that terminates at the floor of the cooling channel. A bore extends through the oil inlet from the lower extremity up though the floor of the cooling channel. The circumference of the bore increases from the upper extremity to the lower extremity, so the oil inlet forms a funnel shape.

Exemplary piston assemblies and methods of making the same are disclosed. An exemplary piston assembly may include a piston crown and a piston skirt that is received in a central opening of the crown. The piston crown may include a ring belt portion defining, at least in part, a cooling gallery. The crown and skirt may each further include corresponding mating surfaces that extend about a periphery of the crown and skirt. The skirt mating surface and crown mating surface may generally be secured to each other that the crown and the skirt cooperate to form a continuous upper combustion bowl surface. The skirt and crown may cooperate to define a radially outer gap about a periphery of the piston crown.

Piston assembly

Exemplary piston assemblies and methods of making the same are disclosed. An exemplary piston may include a piston body defining a piston axis, the piston body having a skirt and forming a lower surface of a cooling gallery. The body may include radially inner and outer body mating surfaces. The piston may further include a cooling gallery ring cooperating with the piston body to form the cooling gallery. The piston body and cooling gallery ring may be joined together along radially inner and radially outer interface regions to form a generally one-piece piston assembly. In some exemplary approaches, mating surfaces of the body and ring may be positioned adjacent a support surface configured to inhibit or prevent weld spatter formed in a process joining the ring and body from the cooling gallery.

Piston assembly with weld support

An exemplary piston may include a piston body having radially inner and outer body mating surfaces. The piston may further include a cooling gallery ring cooperating with the piston body to form a continuous upper combustion bowl surface and a cooling gallery. The cooling gallery ring may have radially inner and outer ring mating surfaces abutted along their corresponding radially inner and outer body mating surfaces, such that the cooling gallery is substantially enclosed. The piston body and cooling gallery ring may be joined together along the radially inner and radially outer interface regions to form a generally one-piece piston assembly. The radially outer interface region may be elongated in a direction parallel to the piston axis, e.g., facilitating a laser welding joining process.

Laser welded piston assembly

An exemplary method of making a piston assembly may include providing a piston crown defining at least in part an upper combustion bowl surface. The piston crown includes at least one crown mating surface. The method further comprising moving the crown mating surface in proximity to a skirt mating surface defined by a piston skirt, wherein the crown and skirt cooperate to define a cooling gallery extending about a periphery of the crown. The method may further include bonding the crown and skirt together by initiating an electric current along a conductive path between the crown and skirt mating surfaces, the conductive path comprising at least one conductive material extending from the crown mating surface to the skirt mating surface.

Method for bonding piston components

A piston assembly and a method of making the same. Exemplary piston assemblies may include a piston crown having a ring belt portion defining a cooling gallery, and a strut extending away from the ring belt portion to define a wrist pin bore. The piston may further include a piston skirt assembly secured to the strut. The piston skirt assembly may include two separate portions that each have a closure plate formed integrally with the portion, with the closure plate generally enclosing the cooling gallery. Exemplary methods of assembling a piston may include providing a piston crown having a ring belt portion defining a cooling gallery and a strut extending away from the ring belt portion to define a wrist pin bore. The methods may further include forming a piston skirt assembly having two portions having a closure plate integrally formed therewith, and securing the skirt to the crown.

A cooling channel cover for a one-piece piston of an internal combustion engine, the piston having a closed cooling channel that runs around inside the piston crown, at the level of the piston ring band, and a ring-shaped recess provided between the piston ring band and the piston shaft, wherein the piston shaft is connected with the piston hubs suspended on the piston crown. In such a piston, an easy to assemble cooling channel cover is achieved in that a one-piece, plastic spring steal ring, U-shaped in cross-section, having radially angled outer and inner shanks around the circumference, has at least one film hinge running around the circumference of the ring. The film hinge allows at least one radial deflection of at least one of the shanks, in such a manner that in order to close off the cooling channel, the shanks engage in a stepped conical recess on the inner edge of the cooling channel.

Cooling channel cover for a one-piece piston of an internal combustion engine

A cooling channel cover for a one-piece piston of an internal combustion engine, the piston having a closed cooling channel that runs around inside the piston crown, at the level of the piston ring band, and a ring-shaped recess provided between the piston ring band and the piston shaft. The piston shaft is connected with the piston hubs suspended on the piston crown. In such a piston, an easy to assemble cooling channel cover is achieved by a one-piece plastic/spring steel ring that is U-shaped in cross-section, having a ring bottom and an outer shank around the circumference, molded onto the ring bottom and angled off radially to the outside, and an inner shank around the circumference, angled off radially to the inside. The plastic ring has a first radial division having a mouth width and a second radial division, opposite the first division, which does not separate the radially angled outer shank that runs around the circumference, to form a film hinge for radial deflection of a ring shank formed by the film hinge.

A cooling channel cover for a one-piece piston of an internal combustion engine, the piston having a closed cooling channel that runs around inside the piston crown, at the level of the piston ring band, and a ring-shaped recess provided between the piston ring band and the piston shaft, wherein the piston shaft is connected with the piston hubs suspended on the piston crown. In such a piston, an easy to assemble cooling channel cover is achieved by means of a one-piece plastic/spring steel ring that is U-shaped in cross-section.

A cooling channel cover for a one-piece piston of an internal combustion engine, the piston having a closed cooling channel that runs around inside the piston crown and a ring-shaped recess between the piston ring band and the piston shaft. There is an easy to assemble cooling channel cover comprising a one-piece plastic/spring steel ring that is U-shaped in cross-section, having a ring bottom and an outer shank around the circumference, molded onto the ring bottom and angled off radially to the outside, and an inner shank around the circumference, angled off radially to the inside. There is a fist radial division having a mouth width (M) and a second radial division forming a first film hinge for radial deflection of one of the ring shanks and a second film hinge that permits at least one radial deflection of at least one of the radially angled shanks. In order to close off the cooling channel, the shanks engage in a stepped conical recess of on an inner circumferential edge of the cooling channel.

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Highland, MI, United States of America

Dieter Gabriel