Process design basis
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 precision parts 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.
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,precision parts 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
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. precision parts 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.