摘要:
A cylinder liner cast into a reciprocating piston engine made of a supereutectic aluminum/silicon alloy which is free of mixed-in particles of hard material and which is composed in such a way that fine silicon primary crystals and intermetallic particles automatically form from the melt as hard particles. A blank is allowed to grow from finely sprayed melt droplets by spray compaction, with a fine distribution of hard particles being produced by setting the spray for small melt droplets. The blank can then be formed by cold extrusion to create a shape approximating the cylinder lining. After premachining, the surface is fine machined, honed in at least one stage and then the hard particles lying at the surface are mechanically or chemically exposed, forming plateau areas of hard particles which project above the remaining surface of the base microstructure of the alloy. The mechanical exposure of the primary crystals or particles is carried out by a honing process using felt strips which are cylindrically shaped on the outside and a slurry of SiC particles in honing oil. The chemical exposure of the primary crystals or particles is carried out by using aqueous alkali. The fine-grained, hard particles formed from the melt and also the mechanical exposure of the hard particles on the surface of the cylinder results not only in high wear resistance and high contact area of the surface, but also in gentle treatment of the piston and its rings.
摘要:
The invention relates to a cylinder liner, cast into a reciprocating piston engine, of a highly hypereutectic aluminum/silicon alloy which is free of hard material particles independent of the melt and has such a composition that fine primary silicon crystals and intermetallic phases automatically form from the melt as hard particles. By spray-compacting, a blank of finely sprayed melt droplets is caused to grow, a fine distribution of the hard particles being produced by controlled introduction of small melt droplets. The blank can be transformed by an extrusion step into a form approximating the cylinder liner. After subsequent premachining with chip removal, the running surface is precision-machined and subsequently honed in at least one stage, after which the hard particles located in the running surface are exposed, plateau faces of the particles being formed, which faces protrude from the remaining surface of the matrix structure of the alloy. The exposing of the primary crystals and/or particles is effected chemically, using aqueous alkali. Owing to the fine-grained hard particles formed in the melt and to their large proportion in the matrix structure and owing to the exposing of the hard particles in the matrix structure, not only high wear resistance and a high load bearing proportion of the running surface result, but also the possibility of using inexpensive piston ring fittings and piston coatings with, at the same time, low oil consumption and correspondingly low hydrocarbon emissions.
摘要:
The invention relates to a cylinder liner sealed into a reciprocating piston engine comprising a supereutectic aluminum/silicon alloy which is free of mixed-in particles of hard material and which is composed in such a way that fine silicon primary crystals and intermetallic particles automatically form from the melt as hard particles. A blank is allowed to grow from finely sprayed melt droplets by spray compaction, with a fine distribution of hard particles being produced by setting the spray for small melt droplets. The blank can then be formed by cold extrusion to create a shape approximating the cylinder lining. After premachining, the surface is fine machined, honed in at least one stage and then the hard particles lying at the surface are mechanically exposed, is forming plateau areas of hard particles which project above the remaining surface of the base microstructure of the alloy. The mechanical exposure of the primary crystals or particles is carried out by a honing process using felt strips which are cylindrically shaped on the outside and a slurry of SiC particles in honing oil. The fine-grained, hard particles formed from the melt and also the mechanical exposure of the hard particles on the surface of the cylinder results not only in high wear resistance and high contact area of the surface, but also in gentle treatment of the piston and its rings.
摘要:
The invention relates to a radial piston pump (1) for high-pressure fuel generation in fuel injection systems of internal combustion engines, in particular in a common rail injection system, having a drive shaft (4) which is mounted in a pump casing (2) and has an eccentric shaft section (6) on which a running roller (8) is mounted, and having preferably a plurality of pistons (16), which are arranged in a respective cylinder (14) radially with respect to the drive shaft (4) and each have a piston footplate (18), which makes contact with the circumferential surface (10, 12) of the running roller (8), at their ends facing the running roller (8). The invention provides that at least that surface (28) of the piston footplate (18) which is in contact with the circumferential surface (10, 12) of the running roller (8) consists of a wear-resistant material, namely of hard metal, a ceramic material, a cast carbide material, or cermet.
摘要:
A method of producing a cylinder head of an internal combustion engine, comprising a cylinder head housing made of an aluminum material and having a base plate fitted into the combustion-chamber-side base wall of the cylinder head housing and made of a highly heat-resistant material. The combustion chamber plate is connected to the base wall of the cylinder head housing by friction welding.
摘要:
The invention relates to a radial piston pump (1) for high-pressure fuel generation in fuel injection systems of internal combustion engines, in particular in a common rail injection system, having a drive shaft (4) which is mounted in a pump casing (2) and has an eccentric shaft section (6) on which a running roller (8) is mounted, and having preferably a plurality of pistons (16), which are arranged in a respective cylinder (14) radially with respect to the drive shaft (4) and each have a piston footplate (18), which makes contact with the circumferential surface (10, 12) of the running roller (8), at their ends facing the running roller (8). The invention provides that at least that surface (28) of the piston footplate (18) which is in contact with the circumferential surface (10, 12) of the running roller (8) consists of a wear-resistant material, namely hard metal, a ceramic material, a cast carbide material or cermet, and/or that at least part of the running roller (8), in particular at least part of the circumferential surface (10, 12) of the running roller (8), consists of a wear-resistant material, namely of hard metal, a precision-cast material, a cast carbide material, a sintered tool steel or an alloyed nitriding steel and/or that the piston (16) consists of a ceramic material.