Cylinder block machining process designEngine parts engine block is a more complex structure of spare parts box, its high precision, com plex process, and the processing quality will affect the overall performance engine, so it has beco me the engine manufacturer's focus parts one. 1.Technical Characteristics of the engine cylinder blockCylinder cast for a whole structure, and its upper part 4 cylinder mounting hole; cylinder standar d cylinder is divided into upper and lower divisions into two parts; cylinder to the rear of the fron t-side arrangement of the previous three coaxial mounting hole of the camshaft and the idler axl e hole.Cylinder process features are: the structure of complex shape; processing plane, more than hole s; uneven wall thickness and stiffness is low; processing of high precision typical of box-type proc essing part. The main processing of the surface of cylinder block top surface, the main bearing sid e, cylinder bore, the main and camshaft bearing bore holes and so on, they will directly affect the machining accuracy of the engine assembly precision and performance, mainly rely on precision equipment, industrial fixtures reliability and processing technology to ensure the reasonableness.2.Engine block process design principles and the basis forDesign Technology program should be to ensure product quality at the same time, give full consi deration to the production cycle, cost and environmental protection; based on the enterprises ab ility to actively adopt advanced process technology and equipment, and constantly enhance their level of technology. Engine block machining process design should follow the following basic prin ciples:(1) The selection of processing equipment ,the principle of selection adopted the principle of sel ection adopted the principle of combining rigid-flexible, processing each horizontal machining ce nter is located mainly small operations with vertical machining center, the key process a crank hol e, cylinder hole, balancer shaft hole High-speed processing of high-precision horizontal machinin g center, an upper and lower non-critical processes before and after the four-dimensional high-ef ficiency rough milling and have a certain adjustment range of special machine processing; (2) foc us on a key process in principle process the body cylinder bore, crankshaft hole, Balance Shaft hol e surface finishing and the combination of precision milling cylinder head, using a process focused on a setup program to complete all processing elements in order to ensure product accuracy The key quality processes to meet the cylinder capacity and the relevant technical requirements; According to the technological characteristics of automobile engine cylinder block and the prod uction mandate, the engine block machining automatic production line is composed of horizontal machining center CWK500 and CWK500D machining centers, special milling/boring machine, ver tical machining centers matec-30L and other appliances.(1) top and bottom, and tile covered only the combination of aperture rough milling machine de dicated to this machine to double-sided horizontal milling machine, using moving table driven par ts, machine tools imported Siemens S7-200PLC systemcontrol, machine control cabinet set up an independent, cutting automate the process is complet ed and two kinds of automatic and adjust the state;(2) high-speed horizontal machining center machining center can be realized CWK500 the maxi mum flow of wet processing, but because of equipment, automatic BTA treatment system through the built-in tray under the wide-type chip conveyor and the completion of the machining center can be dry processing; machine tool spindle speed 6000r/min,rapid feeding speed 38m/min;(3) The combination of front and rear face rough milling machine tool using hydraulic transmissi on; control system imported Siemens S7-200PLC system control, machine tools have a certain fle xibility;(4) The special machine TXK1500 this machine vertical machining center by the modification of shape, with vertical machining center features and performance, this machine has high strength, high wear-resistant, high stability, high accuracy, high-profile etc.;(5) high-speed vertical machining center matec-30L of the machining center spindle high speed 9000r/min.Control system uses Siemens SINUMERIK840D control system;(6) high-speed horizontal machining center spindle CWK500Dhighest speed 15000r/min.3.Engine block machining process design the main contentEngine block complex structure, high precision, arge size, is thin-walled parts, there are a numb er of high precision plane and holes. Engine block machining process characteristics; mainly flat a nd the hole processing, processing of flat generally use planing, milling methods such as processi ng, processing of hole used mainly boring, processing and multi-purpose drilling holes. As the cyli nder complex structure. so how to ensure that the mutual position of the surface processing prec ision is an important issue.3.1 The selection of blankEngine 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 m echanical properties.Improve the rough accuracy, reduction of machining allowance, is to improve the automated pro duction 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 imple mented 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. Therefor e, 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 benchmarkChoose the right processing technology base is directly related to the processing quality can ens ure the parts. Generally speaking, process benchmarking can bedivided into coarse and fine reference base.(1) The baseline for the on-line thick rough, which is particularly important the choice of bench mark crude, if crude benchmark choice unreasonable, will the uneven distribution of machining a llowance, processing and surface offsets, resulting in waste. In the cylinder production line, we ha ve 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 "fora full range of uniform benchmarks, For the longer automated production positioning, therefore, will be divided 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 pro cess. 3.3 Machining Processing Stages and processes of the arrangementsOften a part of many apparent need for processing, of course, the surface machining accuracy ar e different. Processing of high precision surface, often after repeated processing; As for the proce ssing of the surface of low precision, only need to go through one or two on the list. Thus, when t he development process in order to seize the "processing high precision surface, "this conflict, th e reasonable arrangement processes and rational division 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.(1) roughing stage engine block machining process, the arrangements for roughing process, to fu lly carry out rough rough, trim most of the margin in order to ensure production efficiency;(2) semi-finishing phase of the engine block machining, in order to ensure the accuracy of the mi ddle of some important surface processing, and arrange some semi-finishing operations, will be r equired accuracy and surface roughness of the surface of the middle of some processing to comp lete, while demanding the surface of semi-finished, to prepare for future finishing;(3) The finishing stage of requiring high accuracy and surface roughness of the surface processin g;(4) secondary processing, such as small surface screw holes, you can finish of the major surface after the one hand, when the workpiece deformation process little impact at the same time also r educed the rejection rate;In addition,if the main surface of a waste,these small the surface will n ot have to be processed,thus avoiding a waste of man-hours.However,if the processing is very eas y for a small surface bumps the main surface,it should be placed on a small surface finish prior to the main surface finishing;(5) should make proper arrangements for secondary processes such as product inspection proce ss,in part roughing stage,the key process before and after processing,spare parts all the processin g has been completed,should be appropriate arrangements.Stage of processing division,has the following advantages:First,it can take measures to eliminate the rough workpiece after the stress,to ensure accuracy; second,finishing on the back,and will no t damage during transport the surface of theworkpiece has been processed;again,first roughing the surface defects can be detected early and promptly deal with rough,do not waste working hours.But most small parts,do not sub very thin.3.4 cylinder surface of the main processing and secondary processes Cylinder surface and suppo rt the main processing operations are:(1) plane processing at present, the milling of engine blocks is the primary means of planar proc essing,domestic milling feed rate is generally 300-400mm/min,and foreign 2000-4000mm/min mi lling feed rate compared to far cry,to be on increasing,therefore,improve the milling feed rate,red uce overhead time is to improve the productivity of the major means of finishing a number of pla ne engine block when the milling feed rate to reach 2399mm/min,greatly improved efficiency; Top surface of the cylinder milling is a key process in the process,the flatness requirements for 0. 02/145mm,the surface roughness of Ra1.6um.Processing in the cylinder,the use of side and spind le bearing bore positioning,top,bottom and middle vagay only aperture while processing used in t he processing line outside of the knife device can better meet the engine block machining accura cy;(2) General holes machining holes in general are still using the traditional processing of drilling, expansion,boring,reaming,tapping and other craft approach. Issues in the design process of speci fic programs,use of coated cutting tools,cutting tools and other advanced tools within the cooling,and using a large flow of cooling systems,greatly improving the cutting speed,improved producti vity;(3) deep hole processing of the traditional processing method is used to grade twist drill feed,lo w efficiency of their production,processing and quality is poor.The deep hole in the engine block processing,the use of gun drilling process;(4) The three-axis machining holes for the cylinder-axis machining holes holes of high precision, long working hours of the restrictive process.Thus,work arrangements,processing methods,tools and so on should be special attention.All cover pre-processing,that is,semi-circular hole and the c ylinder block main bearing cap of the shortage of processing,its main purpose is to remove blank margin,release stress,to prepare for the post-order processing;in crankshaft machining processin g center hole,using double-sided Boring,boring the first holes in the crankshaft hole at one end to 1/2 length,and then turn 180 degrees workbench,form the other end and then bore another 1/2 length.(5) The cylinder bore machining cylinder hole cylinder machining processing is a key process in the one,under normal circumstances,the machining process as a rough boring,semi-fine boring,pr ecision boring and honing.Cylinder bore wall for the early detection of casting defects,eliminate s tress,should be thick cylinder boring holes in advance;due to the structural characteristics of the different cylinder bore,must be in honing process to improve the cylinder bore surface quality.In t he high-volume production,the cylinder bore honing generally use the multi-axis grinding machin e or honing Automatic Line.Here we use honing automatic lines,from the coarse-heng.Fine-heng and testing equipment,composed of three;(6) Cleaning cleaning isdivided into wet cleaning and dry cleaning.Machining cylinder automatic production line using a large flow of wet cleaning;(7) Detect points outside the line detection and line detection of two kinds. Quality inspection in the engine block,according to the actual situation with lines outside the detection,the main use o f coordinate measuring machine integrated measurements of the cylinder,each 200 samples 1-5 pieces,each class random one. 4.SummaryThrough the engine block of the structure and process characteristics of the analysis,discusses t he engine block machining process design principles and basis of the choice of cutting parameter s,and U-turn at high speed milling and boring,for example,design,analysis of the engine cylinder b ody of high-speed milling and turnover boring process,and in the processing need to pay attentio n to.缸体机械加工工艺设计发动机缸体是发动机零件中结构较为复杂的箱体零件，其精度要求高，加工工艺复杂，并且加工加工质量的好坏直接影响发动机整个机构的性能，因此，它成为各个发动机生产厂家所关注的重点零件之一。