1、外文资料 The crank processes specification and development direction The crank processes specification The crank specification is very high, its machine-finishing technological process different and the crank complex degree has the very big difference along with the production guiding principle, but inc
2、ludes following several main stages generally: Localization datum processing； Thick, lathe finishing and rough grinding each host neck and other outer annuluses； Che Lianjing； Drills the oil hole； Correct grinding each host neck and other outer annuluses； Correct grinding Lian Jing； Big, capitellum
3、and key slot processing； Journal surface treatment； Transient equilibrium； Super finishing various journals. May see, the main neck or Lian Jing the turning working procedure all separates with the grinding working procedure, is often middle arrangement some different machined surfaces or the hetero
4、geneity working procedure. After the rough machining can have the distortion, therefore the normal force reduces gradually； Because simultaneously thick, the precision work working procedure carries on separately before, the latter working procedure has the possibility to eliminate the working proce
5、dure error, finally obtains the very high precision and the very low roughness. Thick, the precision work separates, and arranges the alignment working procedure behind the cutting force big working procedure, guarantees the processing precision. In order to reduce the distortion which the cutting f
6、orce causes, guaranteed when precision work precision request, correct grinding various journals, uses the single grinding wheel in turn grinding generally. The journal processing requests high, the main neck and the neck uses continually processes many times. Crank machining development direction A
7、long with our country numerical control engine bed unceasing increase, the crank rough machining will be widespread uses in the numerical control lathe, the numerical control the milling machine, the numerical control vehicle broaching machine and so on the advanced equipment to the main journal, th
8、e connecting rod journal carries on the numerical control turning, in the milling, the vehicle - broaching processing, by will effectively reduce the amount of deformity which the crank will process. The crank precision work will be widespread uses the CNC control the crankshaft grinding to carry on
9、 the correct grinding processing to its journal, this kind of grinder will provide grinding wheel automatic function requests and so on transient equilibrium installment, center rest automatic tracking unit, automatic survey, self-compensating system, grinding wheel automatic conditioning, permanent
10、 link speed, will guarantee the grinding quality the stability. In order to satisfy the processing request which the crank enhances day by day, set the very high request to the crankshaft grinding. The modern crankshaft grinding except must have the very high static state, the dynamic rigidity and o
11、utside the very high processing precision, but also requests to have the very high grinding efficiency and more flexibilities. In recent years, requested the crankshaft grinding to have the stable processing precision, for this, had stipulated to the crankshaft grinding process capability coefficien
12、t Cp1.67, this meant requested the crankshaft grinding the actual processing common difference to have the common difference which assigned compared to the crank small one half. Along with the modern actuation and the control technology, the survey control, CBN (cubic boron nitride) the grinding whe
13、el and the advanced engine bed part application, for the crankshaft grinding high accuracy, the highly effective abrasive machining has created the condition. One kind calls it the connecting rod neck follow-up grinding craft. Has manifested these new technical synthesis application concrete achieve
14、ment. This kind of follow-up grinding craft may obviously enhance the crank connecting rod neck the grinding efficiency, the processing precision and the processing flexibility. When carries on the follow-up grinding to the connecting rod neck, the crank take the main journal as the spool thread car
15、ries on revolving, and clamps the grinding all connecting rod neck in an attire. In the grinding process, the wheelhead realization reciprocation swing feed, tracks the biased rotation connecting rod neck to carry on the abrasive machining. Must realize the follow-up grinding, X axis besides must ha
16、ve the high dynamic performance, but also must have the enough tracking accuracy, guarantees the shape common difference which the connecting rod neck requests. The CBN grinding wheel application realizes the connecting rod neck follow-up grinding important condition. Because the CBN grinding wheel
17、resistance to wear is high, in the grinding process medium plain emery wheel diameter is nearly invariable, a conditioning may the grinding 600800 cranks. The CBN grinding wheel also may use the very high grinding speed, may use generally on the crankshaft grinding reaches as high as the 120140m/s g
18、rinding speed, the grinding efficiency is very high. Connecting rod processing and trend of development Connecting rod processing method The connecting rod decomposes (also called connecting rod breaks) the technical principle uses the material break theory, first artificial has the whole forging co
19、nnecting rod semi finished materials big end of hole the fissure, forms the initial break source, then expands with the specific method control fissure, achieved the connecting rod The decomposition processing process enable the decomposition the connecting rod cap, the pole adjoining plane to have
20、the complete meshing jig-saw patterned structure, guaranteed the adjoining plane precise docking, tallies, does not need to carry on the adjoining plane again the processing, simultaneously simplified the connecting rod bolt hole structural design and the whole processing craft, has the processing w
21、orking procedure few, the economical precision work equipment, the nodal wood energy conservation, the product quality high, the production cost low status merit. Main body and the connecting rod cap separate goal. Trend of development At present, the drop for and the die casting connecting rod host
22、, the important status, are facing the powder to forge the steel connecting rod and a powder agglutination steel connecting rod forming craft challenge. Speaking of the domestic present situation, although the powder metallurgy forging industry had certain development, but must provide the mass and
23、the high grade powder metallurgy forging is not mature. Moreover involves the equipment to renew, aspect expense questions and so on technical change, in next one, in long time, domestically produced connecting rod production also by drop forging craft primarily. The connecting rod is one of interna
24、l combustion engine main spare parts, its reducing socket two sizes and the shape position errors have many requests, for example: Diameter, roundness, cylindricity, center distance, parallelism, hole and end surface verticality and so on. How does these erroneous project produce the scene in the wo
25、rkshop to examine, always is in the internal combustion engine profession a quite difficult question. In the connecting rod production, domestic mainly has following several examination method at present: With the spindle survey, namely puts on the spindle in connecting rod two, with the aid of in V shape block, plate, dial guage survey.
