Affect the engine block part of the process design factors are manifold. Specifically, can be understood from the following aspects.     (1) product object, product drawings and technical documents related to the complexity of the engine block under the precision requirements of the process to take corresponding measures. Production targets for the four-cylinder automobile engine cylinder block;
(2) the production program, the production of the nature and type of production of the engine block the production program of 400 million;
(3) The annual effective system of work equipment, working for 320 days, with an average equipment loading rate of 80%, two shifts, 16 hours / day. 3. Engine block machining process design the main content    Engine block complex structure, high precision, large size, is thin-walled parts, there are a number of high precision plane and holes. Engine block machining process characteristics: mainly flat and the hole processing, processing of flat generally use planing, milling methods such as processing, processing of hole used mainly boring, processing and multi-purpose drilling holes. As the cylinder complex structure, so how to ensure that the mutual position of the surface processing precision is an important issue. 3.1 The selection of blank    Engine block on the materials used are generally gray cast iron HT150, HT200, HT250, there is also cast aluminum or steel plate, this engine block using high-strength alloy cast iron. Cylinder in the processing prior to aging treatment in order to eliminate stress and improve the rough casting mechanical properties.
Improve the rough accuracy, reduction of machining allowance, is to improve the automated production line system productivity and processing quality of the important measures. As the foreign box-type parts of rough quality and high precision, and its production-line system has been implemented directly on the blank line, not only eliminating the need for blank check device also saves the rough quality problems due to waste of machining time, increase overall efficiency. Therefore, the refinement of rough is to improve the productivity of the most promising way out. For the engine block production line, can be rough in parts on-line pre-milling six face, removing most of the margin, to facilitate direct on-line parts. 3.2 machining process selection and processing of the benchmark    Choose the right processing technology base is directly related to the processing quality can ensure the parts. Generally speaking, process benchmarking can be pided into coarse and fine reference base.
(1) The baseline for the on-line thick rough, which is particularly important the choice of benchmark crude, if crude benchmark choice unreasonable, will the uneven distribution of machining allowance, processing and surface offsets, resulting in waste. In the cylinder production line, we have adopted for the coarse side of the base;
(2) refined the base of this box for the engine block parts, the general use of “side two sales” for a full range of uniform benchmarks. For the longer automated production line system, due to pin holes in the course of the wear and tear caused by inaccurate positioning, therefore, will be pided into 2-3 segment pin holes used. In the cylinder pin hole of the process, we have adopted to the side, bottom and the spindle hole positioning, in the processing center on the process.
3.3 Machining Processing Stages and processes of the arrangements     Often a part of many apparent need for processing, of course, the surface machining accuracy are different. Processing of high precision surface, often after repeated processing; As for the processing of the surface of low precision, only need to go through one or two on the list. Thus, when the development process in order to seize the “processing high precision surface,”this conflict, the reasonable arrangement processes and rational pision stage of processing. Arrange the order of the principle of process is: after the first coarse refined, the first surface after the hole, the first benchmark other. In the engine block machining, the same should follow this principle. 发动机缸体工艺英文文献和中文翻译(2):http://www.youerw.com/fanyi/lunwen_9964.html