缸体机械加工工艺设计

Cylinder block machining process design

Engine 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. cal Characteristics of the engine cylinder

block

Cylinder 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.

block process design principles and the basis for

Design 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 focuse

d on a setup program to complete all processing elements in order to ensure product accuracy Th

e 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 system

control, 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 throug

h 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/l system uses Siemens SINUMERIK840D control system;

(6) high-speed horizontal machining center spindle CWK500Dhighest speed 15000r/min.

block machining process design the main content

Engine 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 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 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 benchmark

Choose the right processing technology base is directly related to the processing quality can ens

ure the parts. Generally speaking, process benchmarking can be

divided 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

a 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 arrangements

Often 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

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 r,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 the

workpiece has been processed;again,first roughing the surface defects can be detected early and

promptly deal with rough,do not waste working 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 sing 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