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 
  • F02F3/0084—Pistons  the pistons being constructed from specific materials
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
  • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
  • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
  • C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
• • 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 
• • 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 
  • F02F3/0084—Pistons  the pistons being constructed from specific materials
  • F02F3/0092—Pistons  the pistons being constructed from specific materials the material being steel-plate
• • 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
  • 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
  • F05C2201/02—Light metals
  • F05C2201/021—Aluminium
• • 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 steel pistons for internal combustion engines and internal combustion engines with steel pistons and internal combustion engines with steel pistons and a
• Cylinder crankcase made of light metal.
• DE 10 2006 030 699 A1 likewise discloses a steel piston for internal combustion engines which consists of a density-reduced steel alloy of the composition in% by weight Mn: 12-35 Al: 6-16 Si: 0.3-3 C: 0.8 -1, 1 Ti: to 0.03 remainder Fe as well
• Thermal expansion coefficients have as steels, there are significant differences in the operation of internal combustion engines in the thermal
• Piston noise which is one of the main causes for the noise of the crank mechanism in the internal combustion engine, is primarily excited by the piston side forces (piston impact). Due to the rapidly changing piston side force, the piston is pressed from one side of the cylinder bore to the other side. When the engine is cold and with light metal pistons, this effect is particularly noticeable as piston rattling. Therefore, acoustically effective measures for
• the object is achieved by a steel piston with a
• Cylinder crankcases made of light metal alloys with the characteristics of Patent claim 1 and with an internal combustion engine with a steel piston having the features of claim 7.
• CTE Coefficient of expansion
• Particularly suitable stainless steels include in particular steel alloy with a thermal expansion coefficient in the range of 16 to 19 * 10 "6 / K.
• the lower piston part comprises the piston skirt or the piston skirt.
• Diesel piston is the so-called smooth-shaft piston with its closed, interrupted only in the area of the bolt holes shank preferred.
• Versatile are the designs of the piston stems in pistons for gasoline engines. For reasons of weight, because of the higher speeds their shaft shape is limited only to relatively narrow shaft surfaces.
• Typical designs are box pistons, window pistons and asymmetrical pistons with different widths of running surfaces. With the selected stainless steel with high CTE can also be a very good
• Carry out alignment on cylinder crankcase which are constructed of gray cast iron, or which have gray cast iron bushings or gray cast cylinder liners.
• An embodiment of the invention thus comprises the combination of a steel piston with a CTE in the range of 13 to 16 * 10 "6 / K and a cylinder crankcase made of gray cast iron or a CCG with gray cast iron bushings.
• the stainless steels with high CTE (thermal expansion coefficient) according to the invention are particularly preferably selected from stainless steels having a Cr content of 15-26% and a Ni content of 8-15%. Unless otherwise indicated, it is always the content in% by weight or% by mass to understand.
• the Cr content is 17 to 20% and the Ni content is 9 to 13%.
• Ni contents near the upper limit are particularly suitable.
• Stainless steel alloys also required high tensile strength and elongation at break.
• the piston skirt or the piston skirt should absorb the lateral forces without deforming or tearing, on the other hand, it should elastically adapt to the deformations of the cylinder. Preference is therefore given to choosing stainless steels which
• Particularly suitable stainless steels with high CTE include steels with the following essential alloy components (in% by mass):
• the stainless steels are with the following essential
• the steel piston is constructed in one piece from a single steel alloy with a high CTE.
• a casting method such as a low-pressure casting method is used.
• the cooling channel is poured by suitable core method.
• the upper piston part which also includes the piston ring grooves, forged.
• the piston upper part with cooling channel can be produced more cost-effectively by forging technology than by casting technology. Therefore, assembled forged crowns of a high CTE steel alloy and a high CTE steel alloy cast body are particularly preferred.
• both parts can be forged or cast both parts.
• the usual methods in particular welding, induction welding, friction welding, or laser welding can be used.
• Piston upper part are made less demanding.
• the lower piston part is typically larger, or longer than the upper part.
• it usually carries no seals or piston rings or the like.
• the piston is generally guided in the region of the piston skirt or shaft. But there are also known pistons, both in the area of the piston skirt as well as in the area of
• Piston shell are performed.
• the steel alloy with high CTE is used in the area of the piston guide.
• only the piston lower part, comprising the piston skirt or skirt is formed from a steel alloy with a high CTE. Since the comparatively lower thermal conductivity of the stainless steels can be a disadvantage, as it can lead to overheating of the combustion bowl or the whole piston, and multi-part piston can be manufactured with adapted to upper and lower part different material properties. Only one of the two parts consists of a steel alloy with a high CTE.
• the Stahlkoben is constructed two or more parts.
• the piston upper part on a wear-resistant alloyed tempering steel. Since the selected steel alloys for the lower part have only comparatively low thermal conductivities, steels with higher thermal conductivity are also of importance for the upper piston part.
• Particularly suitable steels of the piston upper part include in particular steels from the group MoCr4, 42CrMo4, CrMo4, 31CrMoV6 or 25MoCr4. The choice of material in the two- or multi-part design is nevertheless not limited to steels for the upper piston part.
• Piston top and piston bottom can be joined together by welding or soldering. Friction welding, induction welding or laser welding are particularly preferred.
• FIG. 1 shows a piston (1) in cross section, with upper part (12) and lower part (13),
• an internal combustion engine which has steel pistons and in which the cylinder crankcase (ZKG)
• Light metal is formed. It also includes cylinder crankcases whose
• Runways are formed by other materials, such as cast-cylinder liners or wear protection layers.
• the steel piston is formed at least in the lower part of a high-WAK stainless steel in the range of 14 to 20 * 10 "6 / K.
• As light metal alloy in particular AI alloys are used.
• the socket body is preferably made of a high-strength aluminum alloy or of an aluminum alloy reinforced by reinforcing agent.
• Particularly suitable AI alloys include eutectic to hypoeutectic Al-Si alloys, in particular from the series AISi5 to AlSil 1.
• Particularly preferred are Al alloys with a higher Si content, such as. AISM 1, AISi10 or AISi9, since the WAK usually decreases slightly with increasing Si content.
• the track of the cylinder crankcase can be formed in a known manner by a running Al-Si alloy, metal composite material, wear protection coating or gray cast iron. These can be prefabricated partly as a separate cylinder liner or liner package and in the socket body of light metal alloy
• the cylinder crankcase may be constructed of an Al alloy or optionally also Mg alloy, while the
• Al-Si alloy or gray cast alloy is formed.
• metal composite materials are materials made of metal matrix, in particular of Al alloy, and disperse phase of hard or wear-resistant materials, in particular from silicon particles, ceramic particles or ceramic fibers to understand.
• Suitable metal composite materials are known, for example, under the names Silitec® or Lokasil®. Particularly preferred is the career of the ZKG by a
• Spray compacting layer formed on the cylinder liner or directly on the base material of the socket body It is particularly advantageous if this constructively eliminates the production of a separate cylinder liner.
• the adaptation of the CTE of the steel piston to the light metal alloy of the socket body, or the cylinder crankcase is particularly important because the piston faces as a sliding partner only a thin wear protection coating or spray coating and not a quasi-massive cylinder liner.
• thermal spray coatings according to the LDS process electric arc wire spraying based on iron alloys. These are preferably applied directly to the inner wall of the cylinder bore made of an Al-Si alloy.
• the ZKG in monolithic construction, for example, from a
• hypereutectic AISi alloy such as AISi17Cu4Mg.
• the entire crankcase is preferably produced in the low-pressure Kokilleng goreas.
• crankcase made of a hypoeutectic alloy, in particular an Al-Si alloy with Si ⁇ 11%. Die casting is particularly advantageous.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Combustion & Propulsion (AREA)
• General Engineering & Computer Science (AREA)
• Pistons, Piston Rings, And Cylinders (AREA)
• Cylinder Crankcases Of Internal Combustion Engines (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (5)

Families Citing this family (15)

Citations (3)

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• 2009
  • 2009-10-02 DE DE200910048124 patent/DE102009048124A1/de not_active Ceased
• 2010
  • 2010-09-03 EP EP10750070A patent/EP2483547A1/de not_active Withdrawn
  • 2010-09-03 US US13/390,717 patent/US9051896B2/en not_active Expired - Fee Related
  • 2010-09-03 JP JP2012531256A patent/JP5859440B2/ja not_active Expired - Fee Related
  • 2010-09-03 WO PCT/EP2010/005417 patent/WO2011038823A1/de active Application Filing

Patent Citations (3)

Non-Patent Citations (3)

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