As one of the important parts of automobile, the engine block has complex structure and shape. Processed end face and hole more; And the wall thickness is uneven; High precision requirements, belongs to the typical box processing parts. For this kind of engine cylinder block end machining is mainly milling, cylinder bore is mainly boring. Engine cylinder block often USES gray cast iron as raw material, also have the cylinder block of cast aluminum, still give priority to with gray cast iron now nevertheless, damping sex is better, and the price is cheap, easy production.
For the processing of engine cylinder block, cylinder hole, cylinder head, with what material tool processing efficiency?
Manufacturing process of engine block
(1) casting: casting process can not only meet the performance requirements of engine cylinder, but also lower production cost. However, its casting process is not easy, the casting process is: preparing the furnace charge → smelting metal → pouring → solidification cooling → falling sand cleaning → inspection → qualified casting. Casting defects such as cracks, pores and sand holes are not allowed on the non-machined surface of the engine cylinder.
(2) milling processing: qualified workpiece into the machining workshop for milling processing, first with one side as the benchmark coarse milling, and then on the other end face milling, the end face processing to the size required by the drawing.
(3) boring processing: there are many holes in the engine cylinder. After determining a reference level, carry out rough boring and fine boring respectively, and process the holes to the size required in the drawing.
(4) heat treatment: if the mechanical properties of the engine cylinder are high, heat treatment is required. Preliminary heat treatment before rough processing, to eliminate residual internal stress, prevent the workpiece deformation, cracking; Adjust the hardness to improve the cutting performance. The final heat treatment gives the material all the mechanical properties it had at the time of use before finishing.
Engine cylinder block as one of the five components of the engine, is the foundation of all parts of the engine installation, the product quality, surface granularity, surface precision and other requirements are higher, to complete such a level of processing, the tool is required to have high speed, high precision, high efficiency and other characteristics.
Engine block machining tool scheme
(1) engine cylinder milling tool: the bn-s300 brand of hualing ultra-hard cubic boron nitride blade is adopted, which can significantly improve the productivity and stabilize the cutting performance, and can replace the international first-tier brands such as sangao cutting tools.
(2) engine cylinder boring tool: recommended bn-s300 brand or BNK30 brand, cost-effective, stable cutting performance, engine industry tool one of the representative.
(3) stop chamfering process: customized according to customer demand, the advantage is stable cutting performance, high cost performance.
(4) for the aluminum alloy engine block: the super-hard PCD cutter of hualing is selected for the high-speed milling plane, whose cutting speed can reach 3000m/min, and it has excellent machining characteristics. Hualing superhard PCD reamer is recommended for hole system to improve tool life and ensure high dimensional accuracy and surface roughness.
Note: the structural form of BNK30 CBN tool includes integral type and inlaid type. According to the machining allowance of grey cast iron (machining process), BNK30 of different structure is adopted to ensure longer tool life and higher surface finish (within Ra1.6).
(1) the integrated CBN blades of BNK30 and bn-s300 need to be equipped with the tool holder of hualing super hard special machine;
(2) the tool bar of BNK30 inlaid CBN blade and the tool bar of carbide indexable blade are universal, which can be used by direct clamping;
(3) before choosing CBN tool, it is very important to match the tool, in order to achieve high speed cutting, cost reduction and efficiency, good communication is very important.
Conclusion and prospect
(1) in the processing of engine cylinder hole, can use cheap domestic CBN tool instead of imported CBN tool for cylinder hole semi-fine boring, fine boring high-speed processing.
(2) for the fine boring and machining of engine cylinder hole of gray iron material, the overall CBN blade can not only be fine boring with input below 0.3mm, but also semi-fine boring or rough boring with input above 0.50mm. While the composite PCBN blade can only be boring within a single side of 0.30mm, otherwise the composite PCBN blade will appear the risk of collapse.
(3) in fine boring and machining, according to the verified life of the CBN blade to force tool change, to ensure the safety of the workpiece.
(4) because of the accuracy of engine cylinder hole machining requirements, the use of fine boring automatic compensation system machining center, the precision will be better, of course in the rough machining and semi-fine boring, also can use a special machine.
Page location ： 
