Engine Cylinder Hole Boring Process Analysis And Practice

Based on the processing of the hole of enging cylinders' fine boring of Sino-foreign joint ventures Perkins Company Limited, combining with the research of projects—the design of cylinder-precision boring machine—which is from High-precision MachineTools Ltd. in Jiangsu Province, the research and analysis of manufacture processing technology of cylinder and the hole has been made and on this basis, high precision of boring machine has been acquired.The accuracy of cylinder diameter is about 0.015 mm, and the thickness of wall is uneven and the length is long , about 230mm. A great degree of error of the shape could be accursed during the processing. Therefore, based on the tests, error data and location can be conclude, and through regression analysis, obtained its error curve, and then compensate the shape error by NC program.In addition, the cylinder surface roughness of the bore is large, about Ra2.8～3.2μm, which produces a contradiction with high-precision requirements of the bore. To address this problem, by orthogonal test, analyze the main factors and secondary factors of the impact on the quality of processing, determine the amount of cutting and cooling conditions of the gifted programs. It is ensuring a high dimensional accuracy, while the surface roughness is also greatly increased." Bore top groove " is the step on the top of the cylinder body, the requirements on the depth of tolerance is high, and the size detection is difficult. The designed benchmarks of the engine height - the top surface of benchmarks - the underside of which is not coincident, the tolerance between the two benchmarks are larger than tolerance of the bore top groove. The problem is solved by the selection of cutting process and the design of depth test detection.Finally , on the foundation of the design, the research fruits are used in the design and manufacture of precision boring machine tools. A new low-cost, high-precision cylinder boring machine is produced.