– – visit engine of limited company of Beijing contemporary car job shops technology is in charge of factory machine Mr Li Wenbo
Current, the factory has engine of limited company of Beijing contemporary car two factories, mixed 2004 respectively 2007 put into production, year productivity achieves 500 thousand. The factory has lid of cylinder body, crock and crankshaft 3 product line, product line is used firm soft and of aid half flexible the way that change, the amount of the machining center in new plant increased 15%~20% , in addition, still a few special machine tools coordinate machining center production, the honing machine that includes cylinder body line, rinsing equipment, equipment trying leakage and equipment of cold press fitting. In addition, still own an advanced SPC system, can undertake real time monitoring to product line, spot controller can know the equipment state of product line at any time through monitor, in the light of equipment unusual situation takes step, precaution is undesirable tasted happening, improve product quality thereby, drop a product undesirable article rate. Factory FA produces the application that runs a system, can gain the manufacturing status with detailed product line constantly, achieved trends administration of production.
What engine produces is flexible change will alleviate this kind of pressure, but should realize these target home companies to still a paragraph of very long way wants.
Because engine belongs to the product that onefold big batch produces variety, so engine produces the industry such as the requirement to machining center and mould, aerospace to differ somewhat. Specific requirement includes at 3 o’clock: The first, the acceleration of machining center main shaft should be in 1g above; Main shaft is the largest rotate speed 12 000r/min, main shaft is fast above of feed 50 000mm/min, the 2nd, machining center should have taller precision: 0.002mm/ whole journey of ± of fixed position precision repeats ± of fixed position precision 0.001mm, 0.002mm of precision of INDEX TABLE circumgyrate, the CPK that be being told generally is a machine tool is in 1.33 above; The 3rd, machining center must have high reliability, the MTBF(average time to failure that the machine tool issues in top rotate speed) ≥ 15 000h, the MTBF in real work should achieve 50 000h. To achieve afore-mentioned goals, use tall rigid ram and double pillar structure to ensure treatment precision, use servo electric machinery to reduce sensor, damaged of the cutting tool inside knife library detects; Main shaft did not install a knife to detect, will assure to machine quality; To assure the eduction of scrap of machine tool interior, the machine tool also needs to make special design: Machine area and drive part to be kept apart completely, handwriting of big brae person adjustable shield, in the center of the back row formula that uses bounty groovy structure, cut bits to fall directly from eduction of main shaft lower part, eliminated the possibility that cuts bits to stop, bits of the platoon inside machine uses means of large flow slipstream, instant eduction high temperature cuts bits, avoid quantity of heat to deliver lathe bed; To answer the adverse effect that high speed will come to to take, each control axis is used shrink put adjustable cover, center of ball guide screw is cooling, main shaft oily mist lubricates or use main shaft to mix (Hybrid) cooling system, control main shaft heats up displacement, make sure high speed or low speed condition all can stabilize accurate treatment. To realize efficient cutting treatment, high-powered cutting cutting tool wants to be being attached most importance to especially engine treatment, compound cutting tool of razor blade of razor blade of HSK knife handle, CBN, pottery and porcelain, PCD the wide application that wait, make the cutting function of machining center rises greatly, at the same time taller cutting tool life, can reduce finished cost effectively. In addition, all machining center have A, B two clamping apparatus and two workbench, can come true so flexible turn production, and leave out change the time that clamping apparatus place needs, achieve the goal that produces product diversification.
Current, although flexible product line already by the adoption with engine extensive manufacturer, but very rare factory is to use of 100% flexible product line. Because be in engine production process,this is, lid of cylinder body, crock and crankshaft 3 big finish very hard by machining center entirely. For example, in the rough machining working procedure of semifinished product, a lot of manufacturer still use modular machine tool (special machine tool) , because surplus of the cutting when rough machining is larger, ask main shaft load is bigger, and ask the machine tool has very big tigidity, big torque of low rotate speed often restricts the play of machining center function, so manufacturer very apt chooses modular machine tool. When aperture fastens treatment, use machining center commonly, use the high speed fabricating characteristics of machining center, can complete drill quickly, pour horn, tap and Kong Jia of bore with a reamer to be versed in, realize multitask foreword to machine thereby, more important is machining center can the change according to the market, through changing clamping apparatus and program can realize the treatment of new product quickly. And the characteristic of modular machine tool is rigid efficiency of good, production is tall, but when the product that produces when place produces change, of original product line transform cost very tall. So, at present the manufactory is modular machine tool and machining center cooperate to use, namely rough machining, finish machining and superfinishing use rigid line treatment, aperture fastens treatment to use machining center, tigidity and flexible the scale of equipment is 50:50. As a result of in last few years of engine product change very fast, engine plant is to abiding by the characteristic with agile, fast transition to undertake product line is designed at first, use generally firm soft and the producer mood of aid will answer breed to change brought pressure. The engine plant that builds recently is in abiding by this characteristic while, what also increasing product line stage by stage is flexible change rate, be in for instance boring of line of opening of canister of the canister of thick boring crock of cylinder body, crock of boring of essence of life, crankshaft, finish machining of finish machining of cylinder body end face, crock lid underside also uses machining center to finish in the attempt, the scale of such machining center can achieve 80% above. As the application of bigger, tall tigidity and the machining center of a large number of new technologies, what engine machines is flexible the standard that change will rise further.
As identical as major production industry, the engine of our country makes level and country foreign minister is compared or have certain difference. It is automation rate above all, automation rate of home is in basically the level of 70%~80% . Serve as the well-known company of front row, the automation rate of the factory had reached engine of limited company of Beijing contemporary car 98% , outside the own examination that divides pair of work, arrive from the investment of semifinished product of eligible workpiece get offline to implement automation entirely. A difference reflects the performance in equipment itself, include the precision of equipment itself and its stability and dependability, the fault rate of advanced equipment of abroad wants far the equipment under home, especially the inchoate breakdown of equipment, this also is to bring about home to produce character to measure a under abroad main reason.
In future, engine is made will side with more flexible the way that change is ongoing. 10 years ago, most factory is designing the metropolis when product line to be given priority to with modular machine tool; Had begun the use machining center of small lot before developing a few years, right now machining center amount occupies the 40%~50% of equipment sum total about; Achieved 60%~70% 2007. Increase of tigidity and precision ceaselessly as machining center, main shaft rate rises ceaselessly with all sorts of parameter and the application of new technology, machining center can reach the each function target of modular machine tool likewise. Say so, starting a mechanism to create the development climate henceforth is more flexible change. Be in truckload in making, we can have come true to plan production according to the client’s order, namely straight alignment production. But, most engine manufacturer especially machine treatment is far still did not reach this kind of level, normally answered plan is the stocks with be built certain for every breed, but do not accord with JIT to produce a concept again so, realizing 0 inventory is the objective that JIT place pursues. In addition, the diversification of breed is one of trends that engine produces. What engine produces is flexible change will alleviate this kind of pressure, but should realize these target home companies to still a paragraph of very long way wants.