Patents Assigned to Mahle GmbH
  • Publication number: 20040177505
    Abstract: A method for the production of a forged piston for an internal combustion engine, having a combustion depression provided on the piston head. The piston is formed from a first cylindrical unmachined part having at least one flat face made of oxidation-resistant steel and a second cylindrical unmachined part having at least one flat face made of hot-forgeable steel, with the same diameters. The two unmachined parts are formed to produce a piston blank, by means of forging, causing the combustion depression to be formed from oxidation-resistant steel. The piston blank is subsequently finished via machining to produce a piston ready for installation in the internal combustion engine.
    Type: Application
    Filed: December 12, 2003
    Publication date: September 16, 2004
    Applicant: Mahle GmbH
    Inventors: Karlheinz Bing, Gerhard Bucher
  • Publication number: 20040177503
    Abstract: A method for the production of a forged piston for an internal combustion engine, having a combustion depression provided on the piston head. The piston is formed from a first cylindrical unmachined part having at least one flat face made of oxidation-resistant steel and a second cylindrical unmachined part having at least one flat face made of hot-forgeable steel, with the same diameters (d), in each instance. The two unmachined parts are formed to produce a piston blank by means of forging, causing the combustion depression to be formed from oxidation-resistant steel. Subsequently the piston blank is finished via machining to produce a piston ready for installation in the internal combustion engine.
    Type: Application
    Filed: December 12, 2003
    Publication date: September 16, 2004
    Applicant: Mahle GmbH
    Inventors: Karlheinz Bing, Gerhard Bucher
  • Publication number: 20040177504
    Abstract: A method for the production of a forged piston for an internal combustion engine, having a combustion depression provided on the piston head. The piston is formed from a first tube-shaped unmachined part made of oxidation-resistant steel, having at least one join surface, and a second cylindrical unmachined part made of hot-forgeable steel, having at least one join surface. The join surface of the first unmachined part is shrunk onto the join surface of the second unmachined part. The two unmachined parts are formed to produce a piston blank, by means of forging, causing at least the combustion depression to be formed from oxidation-resistant steel. Subsequently the piston blank is finished via machining to produce a piston ready for installation in the internal combustion engine. Simplified and cost-effective production of a piston having a reduced tendency to oxidize at the edge of the depression, and improved protection against wear caused by erosion is achieved.
    Type: Application
    Filed: December 12, 2003
    Publication date: September 16, 2004
    Applicant: Mahle GmbH
    Inventors: Karlheinz Bing, Gerhard Bucher
  • Patent number: 6789460
    Abstract: A multipart cooled piston for a combustion engine has a piston upper part of steel comprising a combustion bowl and a ring wall with ring belt, and a piston lower part comprising a piston skirt, pin bosses for receiving the piston pin connecting the piston to the connecting rod, and pin boss supports connected to the piston skirt. An inexpensive manufacture and high form stability are achieved in that a cooling channel formed in the piston upper part has holes towards the piston crown spread over its circumference, with the piston material present between such holes forming supporting ribs that each form sections of an all-round ring rib radially to the longitudinal piston axis (K), The piston lower part has an annular and all-round carrier rib with a connection surface connected to the pin boss supports.
    Type: Grant
    Filed: October 11, 2002
    Date of Patent: September 14, 2004
    Assignee: Mahle GmbH
    Inventor: Hans-Jürgen Köhnert
  • Patent number: 6772846
    Abstract: A method for drilling shaker bores into a cooling channel of a single-part piston, in which gudgeon-pin bosses each having a gudgeon-pin bore and piston shaft elements are molded onto the piston head via a tie-up substantially extending fully around in the form of a ring. Passage bores are drilled into the tie-up coaxially with the shaker bores to be drilled into the cooling channel, and the shaker bore is drilled into the underside of the piston head with a drilling bit inserted in the respective passage bore.
    Type: Grant
    Filed: March 7, 2003
    Date of Patent: August 10, 2004
    Assignee: Mahle GmbH
    Inventor: Rainer Scharp
  • Patent number: 6763758
    Abstract: A multi-part cooled piston for an internal combustion engine comprises a one-piece piston upper part having a combustion bowl and an annular wall with a piston-ring part, and a one-piece piston lower part having a box-like piston skirt, and bosses to receive the piston pins joining the piston to the connecting rod and boss supports, which are joined to the piston skirt. A cooling channel is formed through the piston upper part and also the piston lower part and is limited thereby in its cross section. A reduction of the compression height and an increase of the heat load can be achieved with this piston despite increasing engine power. The piston can also be assembled without microstructural change. The piston upper part and the piston lower part are provided with support elements having seating faces, which form a first and a second seat.
    Type: Grant
    Filed: September 18, 2002
    Date of Patent: July 20, 2004
    Assignee: Mahle GmbH
    Inventors: Peter Kemnitz, Dieter Messmer
  • Patent number: 6729291
    Abstract: A multipart cooled piston for an internal combustion engine comprises an upper part and a lower part of the piston. The two parts are screwed together via a threaded bolt that is arranged on the upper part of the piston, and a threaded bore that is drilled into the lower part of the piston. The threaded bore is arranged in an area of the lower part of the piston that is thin-walled to such a degree that it is deformed like a plate spring as the two parts of the piston are screwed together, so that no other safety means such as a lock nut are required for securing the assembled piston.
    Type: Grant
    Filed: March 6, 2003
    Date of Patent: May 4, 2004
    Assignee: Mahle GmbH
    Inventors: Rainer Scharp, Dieter Messmer
  • Patent number: 6726217
    Abstract: The aim of the invention is to prevent deposition of material on the piston ring flank (6) of a piston ring (3) for the piston (1) of an internal combustion engine. To this end, said piston ring is provided with channels (7) which are distributed on the circumference of said piston ring flank and which preferably are positioned radially thereon. Said channels are produced on the piston ring in a simple manner by using a laser.
    Type: Grant
    Filed: June 14, 2001
    Date of Patent: April 27, 2004
    Assignee: Mahle GmbH
    Inventor: Wolfgang Issler
  • Patent number: 6722263
    Abstract: The aim of the invention is to provide an easy fastening of a tubular supply or a vertical pipe in a bottom covering of a cooling chamber for pistons of internal combustion engines, e.g. in a circular covering of a cooling channel of an articulated-skirt piston. To this end, the vertical tube or the tubular supply is clipped into the bottom covering or is fastened thereto by a detent connection.
    Type: Grant
    Filed: June 14, 2002
    Date of Patent: April 20, 2004
    Assignee: Mahle GmbH
    Inventors: Klaus Keller, Peter Kemnitz, Roland Lochmann
  • Patent number: 6698391
    Abstract: A multipart cooled piston for a combustion engine comprises a piston upper part of steel comprising a combustion bowl and a ring wall with ring belt, and a piston lower part comprising a box-shaped piston skirt, pin bosses for receiving the piston pin connecting the piston to the connecting rod, and pin boss supports connected to the piston skirt, an inexpensive manufacture with high form stability and improved cooling system is to be achieved in that a cooling channel formed in the piston upper part has holes spread over its circumference towards the piston crown, with the piston material present between such holes forming supporting ribs that each form sections of an all-round ring rib radially to the longitudinal piston axis (K), in that the piston lower part has an annular and all-round carrier rib connected to the pin boss supports, and in that the piston upper part and the piston lower part are non-detachably connected by means of the ring rib and the carrier rib.
    Type: Grant
    Filed: October 11, 2002
    Date of Patent: March 2, 2004
    Assignee: Mahle GmbH
    Inventor: Peter Kemnitz
  • Patent number: 6698392
    Abstract: A single-part cooling channel piston for a combustion engine with a piston head of forged steel comprises a combustion bowl in the piston crown, a ring wall with ring belt and an all-round closed cooling channel level with the ring belt. The piston skirt is connected to the pin bosses attached to the piston head. Inexpensive manufacture together with improved cooling and good form stability of the piston is achieved by providing the cooling channel with holes spread over its circumference towards the piston crown and spaced such that the piston material present between such holes forms supporting ribs for the piston crown.
    Type: Grant
    Filed: October 11, 2002
    Date of Patent: March 2, 2004
    Assignee: Mahle GmbH
    Inventors: Hans-Jürgen Köhnert, Peter Kemnitz
  • Patent number: 6691666
    Abstract: In a multipart cooled piston (20) for a combustion engine with a piston upper part (1) of steel comprising a combustion bowl (3) and a ring wall (4) with ring belt (11), and with a piston lower part (2) comprising a piston skirt (9), pin bosses (12) for receiving the piston pin connecting the piston (20) to the connecting rod, and pin boss supports (6) connected to the piston skirt (9), and in a method for manufacture of such a piston (20), inexpensive manufacture and good form stability are to be achieved in that a cooling channel (7) formed inside the piston upper part (1) has forged supporting ribs (8) in its area extending to the combustion bowl (3), which each form sections of an all-round ring rib (5) with a connection surface radially to the longitudinal piston axis (K), in that the piston lower part (2) has an annular and all-round carrier rib (10) with a connection surface connected to the pin boss supports (6), and in that the piston upper part (1) and the piston lower part (2) are non-detachably co
    Type: Grant
    Filed: January 22, 2003
    Date of Patent: February 17, 2004
    Assignees: Mahle GmbH, Volvo Powertrain Corp., Hirschvogel Umformtechnik GmbH
    Inventors: Gerhard Berr, Armin Ihle, Henk Ravenshorst, Magnus Horn, Lars Lundin
  • Patent number: 6659062
    Abstract: The invention relates to a piston for internal combustion engines whose piston head presents an annular cooling channel which on its end open towards the piston shaft is closed off by an appropriately shaped wall element which is radially divided in at least one place. The aim of the invention is to improve heat dissipation in such a piston. To this end the periphery of the wall element is provided with several radially arranged, evenly distributed transverse walls which extend axially into the cooling channel.
    Type: Grant
    Filed: December 5, 2001
    Date of Patent: December 9, 2003
    Assignee: Mahle GmbH
    Inventor: Wolfgang Issler
  • Patent number: 6647861
    Abstract: The invention relates to a cooled piston for internal combustion engines. The inventive piston is provided with an annular cooling channel on the periphery of the piston head. Said cooling channel, at its end that is open towards the piston shaft, is closed by a correspondingly shaped wall part that is radially split at least once. The aim of the invention is to improve the supply of cooling oil in the cooling channel. To this end, the wall part at the end allocated to the split is provided with a respective recess and with an upturned S-bend section that serves to deflect the cooling oil jet.
    Type: Grant
    Filed: December 10, 2001
    Date of Patent: November 18, 2003
    Assignee: Mahle GmbH
    Inventors: Detlef Jacobi, Rolf Wellandt
  • Patent number: 6622613
    Abstract: A multipiece piston comprises a steel upper part and a lower part which is screwed to the upper part and which contains the hubs. The design of the piston improves the strength of the lower part and its resistance to material defects, and reduces production cost. The lower part of the piston consists of a precipitation-hardened ferrite-pearlite steel, preferably according to EN 10267 and with added titanium. The hubs of the lower part are preferably not reinforced with bushings.
    Type: Grant
    Filed: September 6, 2001
    Date of Patent: September 23, 2003
    Assignee: Mahle GmbH
    Inventors: Jochen Kortas, Stefan Lipp, Wilfried Sander
  • Patent number: 6623240
    Abstract: A guide blade-adjusting device for a turbocharger has an adjusting ring that is guided in a simple manner on the guide blade carrier plate. The adjusting ring comprises noses projecting in the axial direction. At least one the noses radially guides the adjusting ring on the guide blade carrier plate.
    Type: Grant
    Filed: January 24, 2002
    Date of Patent: September 23, 2003
    Assignee: Mahle GmbH
    Inventors: Stefan Ertl, Roland Schacherer, Achim Voges
  • Publication number: 20030167918
    Abstract: A multi-part cooled piston for an internal combustion engine comprises a one-piece piston upper part having a combustion bowl and an annular wall with a piston-ring part, and a one-piece piston lower part having a box-like piston skirt, and bosses to receive the piston pins joining the piston to the connecting rod and boss supports, which are joined to the piston skirt. A cooling channel is formed through the piston upper part and also the piston lower part and is limited thereby in its cross section. A reduction of the compression height and an increase of the heat load can be achieved with this piston despite increasing engine power. The piston can also be assembled without microstructural change. The piston upper part and the piston lower part are provided with support elements having seating faces, which form a first and a second seat.
    Type: Application
    Filed: September 18, 2002
    Publication date: September 11, 2003
    Applicant: Mahle GmbH
    Inventors: Peter Kemnitz, Dieter Messmer
  • Patent number: 6592690
    Abstract: A method for hardening the grooves of steel pistons of steel piston heads whereby hardening of the bottom of the grooves is avoided. The laser beam is directed onto the sides of the groove in an approximately tangential direction in relation to the outer diameter of the piston.
    Type: Grant
    Filed: October 25, 2001
    Date of Patent: July 15, 2003
    Assignee: Mahle GmbH
    Inventors: Michael Weis, Karl Pfeil
  • Patent number: 6546922
    Abstract: The invention aims to improve the seizure resistance of a piston engine with a light-alloy cylinder having a chrome-plated friction surface. To this end the friction surface of the piston is provided with a coating on the basis of artificial resin in which hard particles are embedded.
    Type: Grant
    Filed: October 29, 2001
    Date of Patent: April 15, 2003
    Assignee: Mahle GmbH
    Inventor: Ulrich Bischofberger
  • Patent number: 6546993
    Abstract: The invention relates to a casting method for producing a box piston which comprises recesses between the hub support and the ring band. The invention aims to further reduce the weight of the piston. The casting cores which produce the recesses can therefore be pivoted during stripping.
    Type: Grant
    Filed: November 16, 2001
    Date of Patent: April 15, 2003
    Assignee: Mahle GmbH
    Inventor: Peter Tilch