摘要:
The invention relates to a method for fine machining a cylindrical inner surface which has materials of different hardnesses in the axial direction, and comprises the following steps: pre-turning of the surface, with at least one softer area of the surface being pre-turned to a greater diameter than a harder area, honing of at least the harder area down to the diameter level of the softer area.
摘要:
A coating for a cylinder bore of a reciprocating engine with an iron, aluminum, or magnesium base comprises a hypereutectic aluminum/silicon alloy. The alloy is applied to a cylinder wall by thermal spraying.
摘要:
A casting die for the production of a cylinder block/crankcase of an internal combustion engine includes at least one sleeve, which may be moved relative to its axis and is fitted in each case with a cylinder liner, the sleeve keeping open the cylinder bore of the cylinder block/crankcase and extending from a wall on the cylinder-head side of the die to a wall on the crankshaft side of the casting die. The cylinder liner ends at least 3 mm before the wall on the cylinder-head side of the casting die, and the cylinder liner is held at a distance from the wall on the cylinder-head side of the casting die by a spacer.
摘要:
The invention relates to a cylinder crankcase made of an aluminum diecasting alloy with at least one cylinder bore which has at least one cylinder liner made of a hypereutectic aluminum/silicon alloy, in which in each case a piston is arranged so as to be axially movable, the piston comprising at least one piston ring, one piston skirt and one piston crown, the piston having, with respect to its movement relative to the piston ring, a top and a bottom dead center. The invention is characterized in that the cylinder liner ends at most 10 mm below the bottom dead center, and edge regions of the cylinder bore below the cylinder liner consist of the aluminum diecasting alloy.
摘要:
A cylinder-liner blank which preferably consists of a hypereutectic aluminum/silicon alloy and is cast into a crankcase. A special surface treatment achieves better material bonding of the liner in the crankcase. The blank has a roughness of 30 to 60 &mgr;m on its outside, in the form of pyramid-like or lancet-like protruding material scabs or material accumulations. To obtain this roughness, the surface is blasted with particles which are broken so as to have sharp edges and consist of a brittle hard material, preferably high-grade corundum, with an average grain size of about 70 &mgr;m. A fine fraction is formed and is continuously separated off. The average grain size is maintained by adding new particles.
摘要:
A tribological coating made of a copper-free highly hypereutectic aluminum/silicon alloy and/or of a copper-free aluminum/silicon composite material composed such that fine silicon primary crystals and/or silicon particles, intermetallic phases, and oxides form as hard particles during the production of the layers in the atmospheric thermal spraying method and/or are anchored in the structure. The surface of the coating can be machined economically by short-chipping using conventional tools, so that additional alloy elements such as copper for forming additional intermetallic phases such as Al2Cu can be eliminated. This is significant because conventional AlSi cylinder liners in reciprocating engines pose problems in conjunction with certain fuels because of their copper content.
摘要:
A cylinder-liner blank which preferably consists of a hypereutectic aluminum/silicon alloy and is cast into a crankcase. A special surface treatment achieves better material bonding of the liner in the crankcase. The blank has a roughness of 30 to 60 .mu.m on its outside, in the form of pyramid-like or lancet-like protruding material scabs or material accumulations. To obtain this roughness, the surface is blasted with particles which are broken so as to have sharp edges and consist of a brittle hard material, preferably high-grade corundum, with an average grain size of about 70 .mu.m. A fine fraction is formed and is continuously separated off. The average grain size is maintained by adding new particles.
摘要:
The invention relates to a process for precision-machining a cylindrical inner surface, in particular a cylinder bearing surface, which has material of different hardnesses in the axial direction. The cylindrical inner surface is subjected to a precision-turning step, a preliminary honing step and a precision-honing step. The process is distinguished by the fact that the preliminary honing step produces a cone (11) in the cylindrical inner surface, in such a way that the cone (11) widens out from a harder region (4) toward a softer region (6). In the subsequent precision-honing step, the cone (11) is compensated for again in the harder region (4) to produce a cylindrical inner surface, whereas the cone (11) is retained in the softer region (6). This prevents the fine abrasive particles on the precision-honing stone from becoming clogged as a result of contact with the softer region.
摘要:
In a process for casting a metallic semi-finished product into a casting, the semi-finished product is roughened on a surface which faces the casting, then being placed in a defined position in a casting mold and surrounded with casting metal, after which a firm bond is formed between the semi-finished product and the solidified casting metal at the roughened surface. The surface of the semi-finished product is roughened by high-pressure water blasting.
摘要:
In a cylinder liner of an internal combustion engine for casting into a light-metal crankcase to be cast, in order, during the casting in of the cylinder liner, to achieve as good a binding as possible of the cylinder liner to the surrounding casting material, the cylinder liner has on the outer circumference, in the region of the upper dead center of the piston rings of a piston guided in the liner, an activation layer which consists of a material which, due to the heat effect of the liquid casting material, connects metallically more rapidly to the latter than the liner material, and in that the cylinder liner has a rough surface on the outer circumference following the region of the upper dead center.