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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21K—MAKING FORGED OR PRESSED METAL PRODUCTS, e.g. HORSE-SHOES, RIVETS, BOLTS OR WHEELS
  • B21K1/00—Making machine elements
  • B21K1/18—Making machine elements pistons or plungers
• • 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
• • 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
  • F02F3/027—Pistons  having means for accommodating or controlling heat expansion the skirt wall having cavities
• • 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 
  • F02F2003/0007—Monolithic pistons; One piece constructions; Casting of pistons
• • 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
  • F02F2200/00—Manufacturing
  • F02F2200/04—Forging of engine parts
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49229—Prime mover or fluid pump making
  • Y10T29/49249—Piston making

Definitions

• the invention relates to a method for producing an aluminum piston for an internal combustion engine, which is designed as a round-bottomed piston, with a piston crown, with a ring portion and with a direction away in the piston crown direction adjoining the ring part piston shaft having two opposing pin bosses, wherein the piston shaft in Has region of the radially outer end faces of the pin bosses extending in the direction of the piston axis Schaftschreibitati.
• European Patent Application EP 0 167 791 A2 discloses a round-shaft piston of the type mentioned above with shaft returns extending in the region of the pin bosses over the entire axial length of the piston shaft so that these areas do not make contact with the cylinder inner wall after installation of the piston in the engine. These are formed by means of a lathe in the piston skirt, wherein the piston is clamped in its longitudinal direction eccentrically on the lathe in order to screw the stock withdrawals in the piston skirt can.
• the disadvantage here is that with the known from the prior art turning method only Schafet Wegashi can be produced, the depth to the edge of the Schaftrücksacrificing continuously decreases, so that they have an oval shape in cross-section.
• Object of the present invention is therefore to propose a method for producing a piston with stock withdrawals, which can be arbitrarily shaped.
• the piston is produced in the forging process using a forging die, the inner surface of which is designed to be complementary to the outer shape of the piston, in particular to the shape of the piston stem, the stock returns and the non-recessed areas of the piston skirt.
• the inner surface of the forging counter can be any one
• Fig. 3 A, B two versions of the transitions between the withdrawn and the unretained shank areas.
• Fig. 1 shows a piston 1 for an internal combustion engine, which is designed as a round shank piston, consists of aluminum and is produced by forging.
• the piston 1 has a piston crown 2, a crown land 3, a ring section 4 and a piston skirt 5 with pin bosses 6, 6 'and pin bores 7, 7'.
• the piston skirt 5 has lug withdrawals 9, 9 ', that is, the piston skirt 5 is retracted in these areas in the radial direction by 0.5 mm to 2 mm, and that these areas 9, 9 'of the piston axis 10 thus have a distance of 0.5 mm to 2 mm smaller than the unretained areas 11, 11' of the piston shaft 5.
• the transition regions 12, 12 'between the Schawtschreibsure 9, 9' and the non-recessed areas 11, 11 'of the piston shaft 5 as in the present embodiment of FIG. 1 are parallel to each other or (not shown in Fig. 1) in the direction of the piston head 2 or in the direction of the lower, piston bottom facing away from end 15 of the piston shaft 5 conically aufeinan- to run.
• the Schafetschreibsure 9, 9 ' may be shaped as the lateral surfaces of a circular cylinder. However, they may also have an oval shape viewed in cross-section perpendicular to the piston axis 10, the axis 13 of the pin bore 7 (FIG. 2) being the minor axis of the ovality.
• the height 14 of the Schafetschreibddling 9, 9' is here but freely selectable.
• Fig. 2 a section through the piston 1 along the line AA in Fig. T, it is shown that the circumferential extent of the Schaptschreibsure 9, 9 'and the unretained portions 11, 11' of the piston shaft 5 based on the angle ⁇ between a perpendicular to the axis 13 of the pin bore 7 and also perpendicular to the piston axis 10 standing straight line 16 and the piston axis 10 with the transition region 12 'connecting straight line 17 is definable.
• the angle ⁇ has a value of 32 ° in the present embodiment. But it can be between 5 ° and 85 °.
• Fig. 3 shows two embodiments A and B of the transition regions 12a and 12b between the Schapet Wegsure 9 and the non-recessed areas 11 of the piston shaft 5.
• the transition region 12a of FIG. 3A has compared to the areas 9 and 11 each over the entire height 14 of Shaft withdrawal 9 reaching edge 18 and 19 on.
• the transition region 12b according to FIG. 3B connects the two regions 9 and 11 continuously and edge-free.
• a piston blank in the forging process is known from the prior art (for example from DE 10 2005 041 000) and will not be explained in detail.
• the mandrel is used for the shaping of the piston interior and the forging die serves for the shaping of the piston outer surface.
• the forging die has a shape complementary to the shape of the piston outer surface according to FIG. 2, but the forging die has no projections corresponding to the grooves of the ring section 4 and the pin bores 7, 7 '.
• transition regions 12a, 12b or 12b between the Schapet Wegset 9, 9 'and the non-recessed areas 11, 11' of the piston shaft 5 are designed so that they are parallel to the piston axis 10 or either in the direction of the piston head 2 or in the direction of bottom end 15 of the piston shaft 5 conically tapered.
• the reduction of the cylinder inner surface in contact surfaces 11, 11 'of the piston shaft 5 by means of the Schaft Wegsure 9, 9' has the advantage of improving the sliding properties of the piston.
• a round shank with pick-up with respect to a box piston with recessed relative to the ring end faces of the pin bosses in the direction of the pin axis 13 longer pin holes 7, 7 'and thus a larger contact surface for the piston pin, so round shaft pistons are loaded with higher combustion pressures.
• the inventive method has the advantage that the Schaft Wegsure can be shaped arbitrarily. Seen in the direction of the piston axis, the transitional areas between the shaft returns and the unretracted areas of the piston shaft can have any desired shape and, for example, be wave-shaped.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• General Engineering & Computer Science (AREA)
• Pistons, Piston Rings, And Cylinders (AREA)
• Forging (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=43536082

Family Applications (1)

Country Status (5)

Families Citing this family (1)

Citations (5)

Family Cites Families (7)

• 2009
  • 2009-09-04 DE DE102009040120A patent/DE102009040120A1/de not_active Withdrawn
• 2010
  • 2010-09-03 US US13/393,873 patent/US20130000120A1/en not_active Abandoned
  • 2010-09-03 KR KR1020127008047A patent/KR20120068891A/ko not_active Application Discontinuation
  • 2010-09-03 WO PCT/DE2010/001045 patent/WO2011026480A1/de active Application Filing
  • 2010-09-03 CN CN2010800458132A patent/CN102575613A/zh active Pending

Patent Citations (5)

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