Aluminium-alloy engine body of light-weight and high-rigidity single-cylinder diesel engine

Abstract

The invention discloses an aluminium-alloy engine body of a light-weight and high-rigidity single-cylinder diesel engine, comprising a gear chamber cover surface, a bearing seat surface, a cylinder combining surface, an installing bottom surface and cylinder cover fixing screw holes, wherein radiating ribs which are vertically distributed at interval are arranged under the gear chamber cover surface and the bearing seat surface; the thread depths of the cylinder cover fixing screw holes are increased; and the hole sizes for assembling and matching all steel parts are respectively less than the designed sizes. By adopting the structural design scheme, the aluminium-alloy engine body has the advantages that the weight is light, the radiating speed is fast, the strength and the rigidity are high, the matching accuracy of all matched holes can be stably guaranteed, the mechanical performance of the diesel engine is stable and reliable, and the service life of the diesel engine can be ensured from the mechanical structure.

Description

technical field [0001] The invention relates to parts of a single-cylinder water-cooled diesel engine, in particular to a body of a single-cylinder water-cooled diesel engine. Background technique [0002] The body of a single-cylinder diesel engine is the core part. It is the basic assembly of the entire diesel engine. It is equipped with holes for installing the crankshaft, cylinder head, cylinder liner, camshaft, and fuel injection pump, as well as installing bearing seats and gear chambers. The joint surface of the cover, the observation hole cover and the oil shell, the dimensional accuracy, shape and position accuracy of the hole system, and the amount of deformation during the working process directly affect the performance index of the diesel engine. Therefore, for the diesel engine, the body must have enough Stiffness, as little deformation as possible, and as small a mass ratio per unit power as possible. With the expansion of the scope of use of diesel engines an...

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Problems solved by technology

According to the characteristics of cast iron and aluminum alloy, it can be known that the cast aluminum material is ZL106T6 after heat treatment, the allowable stress is 220MPa, which is equivalent to HT200~250, and its mechanical strength is equivalent to that of cast iron, but the elastic modulus of aluminum alloy is 70GPa , while cast iron is 110GPa, it can be seen that the aluminum alloy material is "softer" than cast iron, so after changing the body from cast iron to cast aluminum alloy, its mechanical deformation will increase, which will lead to excessive deformation of the cylinder liner, decrease in mechanical efficiency, and leakage The gas volume increases, the power decreases, the oil leakage increases, the oil consumption increases, and the emission performance deteriorates; the elongation of the cylinder head bolts increases, and the warpage of the top plane of the body increases, which affects the high-pressure sealing performance. Cylinder pad flushing may occur; the deformation of the bearing hole increases, the rolling bearing becomes loose, and the outer ring of the bearing occurs, resulting in early damage to the rolling bearing; the bearing hole and the sealing end faces are warped and deformed, which may cause oil and water leakage

[0003] Through analysis, it is not feasible to use aluminum alloy to replace cast iron in the existing diesel engine body, and structural improvement design must be carried out, because the thermal expansion and contraction coefficients of the aluminum alloy body and the steel parts assembled on it are different, when the diesel engine is working , the temperature of the diesel engine will increase rapidly, thereby destroying the original matching precision, resulting in the above-mentioned defects of the diesel engine, the stability and reliability of the technical performance indicators of the diesel engine are reduced, and the service life is difficult to guarantee

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