As the core functional components of automobiles, engine processing equipment is one of the most important equipment for automobile production. With the acceleration of new models of vehicle companies, engine production lines have increasingly higher requirements for flexibility. Generally, one engine production line needs to be able to produce at least three models. At the same time, the lightweight trend of automobile development makes the material requirements for engine cylinder blocks and cylinder heads change from cast iron to aluminum alloy, which puts forward new and higher requirements for engine processing machine tools.
The main components of the engine are cylinder block, cylinder head, crankshaft, camshaft, connecting rod and so on. Most of the machine tools needed to process these parts are high-efficiency, high-performance, high-reliability CNC machine tools or special CNC machine tools.
1. Engine block processing
The characteristic of engine block processing equipment is that the production process is highly automated, and flexible manufacturing lines are widely used. In terms of cutting tools, diamond milling cutters are often used for surface milling of aluminum cylinders; hard alloy indexable close-tooth milling cutters are generally used for cast iron; complex structured composite tools are widely used in hole processing. In order to improve efficiency, the automatic line often adopts the out-of-line tool adjustment and forced tool change. The key equipment requires high precision, and the processes of fine boring, fine grinding, and fine honing are widely used in active measurement and automatic tool compensation technology. The honing of engine cylinder bores mostly adopts platform net honing technology to obtain the required surface characteristics. Generally, it is carried out on a single-axis or multi-axis vertical honing machine with automatic measuring device, using aluminum oxide, silicon carbide and synthetic diamond honing strips. , Two groups of different honing bars are distributed symmetrically or asymmetrically on the honing head. The honing bars are controlled by a dual depth feed system, and rough honing and fine honing can be completed in one clamping. Cylinder holes or cylinder liners can also be processed by laser micro-holes, which can obtain more ideal surface characteristics equivalent to net honing, which can significantly reduce oil consumption and extend engine overhaul mileage.
2.Engine cylinder head processing
The plane machining, deep hole machining, and hole machining in the machining of engine cylinder heads are similar to the machining of the cylinder block. The difficulty in machining is the machining of the valve seat cone and the duct hole. In order to ensure the coaxiality tolerance of the bottom hole of the valve seat and the bottom hole of the guide tube, the roughing, semi-finishing and finishing mostly use composite tools.
3.Breaking technology of connecting rod separation surface
Breaking is the breaking and separation of the connecting rod cover from the connecting rod body. The ideal separation surface between the connecting rod and the connecting rod cover is brittle fracture without any plastic deformation. The material used is sintered powder metal or high carbon steel, and the fracture groove is processed by laser. The advantage of expanding the connecting rod is that it simplifies the design requirements of the connecting rod and the connecting rod cover, improves the deformation of the large-head hole of the connecting rod assembly, and reduces the manufacturing cost.