The large-scale hydraulic turbine runner leaf blade's numerical control processing craft technology is attributes the hydraulic turbine manufacture to achieve now one of world advanced level important symbols. The runner leaf blade is the hydraulic turbine key component, its manufacture precision to unit's water power performance and so on efficiency has the direct influence, 型面 the processing precision is high, causes the hydraulic turbine to strive the efficiency to enhance a percentage point, all will bring long term and the huge benefit. Leaf blade's numerical control processing involves the various high-tech, overseas also only has the French Ahl Stone, moves 威克 Vannes, Canadian GE, Germany fertile according to incites, the Japanese Hitachi company and so on the manufacture craft is regarding this mature. Because the leaf blade 型面 numerical control processing adds water the turbine manufacture quality superiority, has become to the unit ordering essential specification. In the achievement world the biggest hydro-junction project - - also is now the international interflow type hydraulic turbine single plane capacity biggest Three Gorges water-turbine generator set, my factory and the Ahl Stone company cooperates makes an issue of 左岸 project 14 Taichung 8 units. The Three Gorges hydraulic turbine key component - runner leaf blade's numerical control processing technology to raises our country power plant equipment manufacture level, steps into world advanced technology ranks watershed.

The hydraulic turbine has the interflow type, the axis flows the type, the birthplace flows the type and so on several kinds, the domestic hydraulic turbine leaf blade manufacture uses the sand casting for a long time, and uses the three-dimensional model examination after manual shovel grinding to the technique, after in recent years developed the leaf blade mould pressing to take shape the shovel to rub, the mould pressing takes shape the retreatment and the casting takes shape the numerical control processing technology. The manual shovel rubs way, not only work environment bad, labor intensity big, efficiency low, moreover the leaf blade 型面 quality was bad, reduced the hydraulic turbine efficiency. In order to realize the leaf blade numerical control processing, my factory in 1987 has introduced five axes numerical controls �?milling machine from the German fertile Tanzania company, and has introduced UKLID software from Swiss FIDIS Corporation, in 1996 purchased German tile Deli to hope the tan oak valuable company numerical control planer-type milling machine and the CAMAX software introduction, has provided the technical guarantee for the numerical control processing leaf blade. The successor special to the surface modeling, the knife position computation, the knife position interference inspection, the leaf blade survey, automatically adjusted the adjustment and the processing procedure establishment, the craft attire clamps, the processing way and the cutting tool system disposition and so on has all conducted the thorough research, has had five axes linkages numerical control processing leaf blade's production and the technical ability. Until now has completed the interflow type inborn bridge, the three-bristle cudrania forest, Xinfeng Jiang and the Three Gorges hydraulic turbine leaf blade and the axis flows hydraulic turbine leaf blade's the and so on type wooden Beijing processing.

2 essential technologies and craft implementation

1) leaf blade numerical control processing technical process

The leaf blade numerical control processing technical process see Figure 1.

Chart 1.

2) five axes linkages numerical control programming technology

The a. leaf blade 型面 survey because the casting semifinished materials distribution processing remainder is inconsistent, uses the three dimensional measuring engine to carry on the semifinished materials the three dimensional 型面 survey, the choice is highly effective, is advantageous for computer data acquisition processing and the datum transformation measuring technique, achieved the remainder even cloth the best attire clamps the position.
The b. surface modeling basis primary data composes the leaf blade three dimensional 型面, satisfies the next step of production numerical control processing the code procedure.
After the c. knife position trajectory computation basis reads in the leaf blade modelling the three dimensional 型面 data, the hypothesis processing 型面, the cutting parameter and the cutting tool data, carry on the knife position trajectory computation.
The d. knife position path simulation and the cutting tool interference inspection basis knife position path carries on the simulation processing on the computer to the graph, and the inspection cutting tool interference situation, guarantees when the real machining safe operation.
The e. postpositioned processing carries on postpositioned processing to the knife position path, the production specific engine bed NC code processing procedure.

3) processes the technological process

A. processing equipment

Purchases German numerical control planer-type milling machine main engine power 100kW, the work table size 4.5×13m, has disposed the present world power biggest numerical control multi-purpose 铣头, the numerical control system uses SIEMENS 840C, this engine bed has X, Y, Z, W, the U five coordinates numerical controls and A, the C two rotation axes numerical controls 铣头, forms five axes linkages numerical control processing leaf blade the equipment condition.

B. semifinished materials quality control

The leaf blade is the casting structure, the material is the martensitic stainless steel. Carries on the rough grinding the leaf blade, removes 夹砂, avoids harming the cutting tool. Again carries on UT, the MT crack detection, the inspection flaw condition. Because the leaf blade castability not good and the remainder is uneven, requests to the leaf blade, back to process the remainder, the peripheral remainder control, reduces numerical control processing the man-hour. With the transit survey leaf blade, back processes the remainder, in the leaf blade, back symbolized surveys and processes looks for the correct use 3 orientating groups on time and attaches its coordinate figure. Under and will survey the data to bequeath the foreword with the floppy disk form.

The c. leaf blade attire clamps

The leaf blade contour is irregular, especially the interflow type leaf blade is does not have any datum the free curved surface, the attire to clamp the way the research implements the question which the programming, the processing first must solve. The German VOITH Corporation countershaft flows the type leaf blade to use the axis outer diameter and the flange localization, the vertical attire clamps the way, the interflow type leaf blade uses may adjust 转向�?the hoisting jack localization, the vacuum cup clamps the way. The vacuum cup clamps must to adsorb the spot to grind the pretreatment, its system part occupies the area to be big. We study proposed uses, back 胎具 the localization, welds the block 搭焊 and the bolt 把合 clamps the way, has economically, is highly effective, the operation simple characteristic, it is reported Norwegian GE Corporation and so on also selects this method. The attire clamps the locate mode to the determination work piece reference point, the implementation adjusts, to solves the leaf blade, the back 型面 dislocation this technology difficulty effect is good.

The d. leaf blade adjusts, the survey

Installs with the numerical control engine bed 铣轴 survey in 胎具 on leaf blade 3 orientating groups on time coordinate figure, and in 胎具 on establishes the reference point to carry on adjusts. Uses the RENISHAW measurement system, the development applies to 3 Uygur curved surface leaf blade survey, to processed after the blade section to provide the advanced examination technology.

E. work piece programming

Before the application states the programming technology, the establishment processing leaf blade, back, enters, nearby the water leakage, on the crown, the lower ring welding scarf procedure.

F. leaf blade's processing

Leaf blade processing spot for, back 型面, turnover water's edge and about welding scarf. The use cutting tool for is thick, the fine surface milling cutter, the spiral end mill, a ball milling cutter and so on.

铣削 the way uses 顺铣, adds the refrigerant 铣削 the processing. Enters enters for the choice of direction along the leaf blade modelling parameter line gives, and so on 铣削 the performance is advantageous to the cutting tool diameter and the interference request.

铣削 the width determination and the face work quality and the processing efficiency mutually are the influence, because the milling cutter inclines the processing in the law arrow direction, after the processing the work piece table delivers in person the micro concave arc, each knife 铣削 width bigger, 铣削 residual wave ridge, trough absolute value bigger, gets down the foreword to polish the work load to be bigger. Therefore must reasonably determine each segment movement row of knife the width.

Chart 2 in five axes numerical controls planer-type milling machine processing leaf blade

4) highly effective numerical control cutting tool development application

Application numerical control processing leaf blade technology its processing cost expensive, processes Three Gorges hydraulic turbine leaf blade statistics, processes 1 piece to need 10 day, the entire share processing cycle 5 months, the numerical control planer-type milling machine price approximately 40 million Yuan, man-hour of expense each hour over a thousand Yuan, add the labor cost more than 4 million Yuan, enhances the processing efficiency, reduces processing cost its significance to be specially important, the research, the development, the application highly effective numerical control cutting tool and the processing method, is one of essential technical which needs to solve.

Development domestic product surface milling cutter, spiral end mill

The leaf blade curved surface spot processing needs the surface milling cutter, the turnover, the water's edge and the welding scarf must use the spiral end mill. Uses the overseas cutting tool price to be expensive, for is suitable for the stainless steel material leaf blade processing, we with Harbin technical University, the wadding labor tool factory cooperation development developed have used the paperback bit structure, on press the type to clamp the way, the host angle of deflection for 75° and the pair of front angle surface milling cutter; Developed with the Taiyuan trump card tool factory cooperation development has been possible to trade the first 4 edges cutting, the week edge disposition side bit, may index 4 times of spiral end mills; Has carried on the numerical control cutting tool system development development with the Harbin labor quantity numerical control cutting tool factory.

Experiments the optimal cutter blade

Solves the stainless steel to be difficult to process the question, the key is the bit performance, the domestically produced bit and overseas has the quite big disparity. The overseas bit abrasive resistance may reach the domestically produced bit above 5 ~ 10 times. After to domestic Zhuzhou, Zigong, on hard, Shaanxi is hard and so on the hard alloy manufacturer 9 kind of trademarks bit, to overseas Sweden mountain especially Uygur gram, German Walter, US 肯纳, Israel according to company's the and so on Si Ka, Hitachi, Mitsubishi 10 kind of trademarks bit carries on the massive experiments, optimal price compared to fine bit.

Moreover with Harbin technical University, the wadding labor tool factory cooperation, the development has developed the double-decked edge steps and ladders structure new 型面 milling cutter, solves as a result of the blade section processing remainder not one, thick mill spatial travelling schedule phenomenon. Also has carried on 铣削 the parameter and 铣削 the way optimal, the realization leaf blade is highly effective, the low consumption cutting tool 铣削.

3 conclusions

Hydraulic turbine leaf blade five axes linkages numerical control and so on the Three Gorges, inborn bridge processes successfully, symbolized my factory, our country large-scale hydraulic turbine manufacture has achieved the international advanced level. The leaf blade craft technology innovation, to improves the quality, the enhancement processing efficiency, reduces the tool expense, the economic efficiency is remarkable. Leaf blade's numerical control processing causes the runner to strive efficiency each enhancement! A percentage point, all has the huge economic efficiency to the unit long-term movement, makes the quality after the Three Gorges unit and enters WTO our country generating set manufacturing industry to enter the international market to have the vital significance