Transfer of automatic transmission technology from Germany to Korea

Transcription

1 Seoul 2000 FISITA World Automotive Congress June 12-15, 2000, Seoul, Korea F2000A149 Transfer of automatic transmission technology from Germany to Korea Author 1: Andreas Faulstich, Author 2: T. W. Lee ZF Getriebe GmbH Daewoo Telecom Ltd. P.O P.O. 25 D Saarbrücken,Germany Poryong, Chungnam, Korea ZF has developed and adapted two automatic transmissions to the technical requirements of Daewoo. At the same time, ZF also gave technical assistance on manufacturing and development to DTL. The main emphasis of the know-how-transfer was placed on the thorough training of Korean engineers and workers. Key manufacturing technologies at DTL were optimised in consultation with the production specialists of DTL and ZF. The ZF method for quality planning at Korean and European suppliers was explained and applied. The conversion and analysis of equivalent Korean materials was another important milestone. With regard to development, DTL employees were given detailed training in design, testing and calibration in order to carry out series application work competently on their own. Because of the excellent co-operation between DTL and ZF the project was led to a successful end result. Through competence, professionalism and hard work on both sides, any difficulties which arose during the process of technology transfer were overcome. Keywords: automatic transmission, ZF, DTL INTRODUCTION In September 1994 a development and license agreement between ZF Getriebe GmbH in Germany and Daewoo Precision Industries, later Daewoo Telecom Ltd. (DTL), in Korea was agreed. The licensed products were the automatic transmission 4 HP 14, which had to be adapted to the technical requirements of the car maker Daewoo Motor Company (DWMC), and the automatic transmission 4 HP 16, which was developed by ZF in close cooperation with DTL and DWMC. In January 1997 the production of the automatic transmission 4 HP 14 started at the facilities of DTL in Poryong, Korea. The production of the newly developed automatic transmission 4 HP 16 started two years later, in February This paper is focussing on the main steps of the technology transfer between both companies and both countries. PRODUCTS DESCRIPTION 4 HP 14 4 HP 14 is an automatic transmission for front wheel driven cars with east - west installation and engines up to 183 Nm engine torque and 100 kw power. It has four forward gears, one reverse gear and a fully hydraulic automatic gear shift control system. The constant gear ratio is between 3.07 and The hydrodynamic torque converter is fully operative in first, second and reverse gears. In third gear, the transmission works according to the power splitting principle, i.e. only approx. 40 % of the input power is fed hydraulically into the transmission (via the torque converter), and approx. 60% is transmitted by purely mechanical means. In fourth gear, all input power is mechanically transmitted to the transmission via the torsion damper integrated in the torque converter. The transmission control system operates fully hydraulically. The main components are: - Hydrodynamic torque converter with integral torsion damper - Four speed planetary section - Two helical gear sets and lateral shift - Integrated differential The transmission s configuration can be adapted to match the engine used and specific vehicle conditions. 1

2 Figure 1: DESCRIPTION 4 HP 16 Sectioned T/M 4HP14 The electronic-hydraulic transmission control offers: - Fully-controlled shifts - Two system pressure ranges depending on torque - Electronic recording of vehicle and transmission data - Automatic adaptation of transmission control to external conditions - The electronic control unit contains modules which automatically specify the transmission shift parameters depending on driving style and driving situation. These modules replace the program selector function. - Built-in error diagnosis system in transmission control unit The 4 HP 16 automatic transmission was developed for front wheel driven cars with east - west installation and engines up to 240 Nm engine torque and 132 kw power. It has four forward gears, one reverse gear and an electronichydraulic control system. The transmission can be adapted to engine and specific vehicle conditions. The special features and main components are: - Short unit with high power transmission capacity - Weight-saving thanks to centrally-integrated spur gear pair, with an excellent power to weight ratio - Hydro-dynamic torque converter with a slipcontrolled lock-up clutch, combining a short length with a good drive characteristic. Due to the slipcontrol lock-up clutch which can be engaged in the second, third and forth gear, a good level of efficiency could be achieved and it was possible to design the lock-up clutch without a torsional damper. The converter also ensures less fuel consumption and improved driving comfort - 4 speed planetary transmission, which consists of two simple planetary gear sets and provides four forward speeds using three brakes and two clutches. Even though no freewheels are used, a very high level of shift quality is achieved by using appropriate software and close loop controlled shift sequences. - Two spur gear pairs with drive shaft - Integrated differential - Lifetime oil fill, which is environment-friendly, with recycling advantages and less servicing Further positive affects on fuel consumption were achieved by the bearing cages for the planetary gear set, renunciation of freewheels, only two clutches, optimised shift elements and using two different levels of system pressure depending on engine torque. Figure 2: Sectioned T/M 4HP16 MILESTONES OF TECHNOLOGY TRANSFER After the contract in September 1994, DTL organized a project team automatic transmission and started work end of the same year. The target of 4HP14 production was end of It was a very strong time schedule, because the first project has be finalized within two years. In order to reduce the time schedule, all activities were done in parallel, such as - design and specification fix Sep to Apr. 1995, 2

3 - long term tools release Feb. to Apr. 1995, - calibration Feb to Mar. 1996, - parts localization since Feb. 1995, - building construction Apr to Feb. 1996, - bench & vehicle durability test Jul to Sep machine & equipment installation Feb to Oct DTL started the 4HP14 mass production for the Daewoo Motors vehicles Nubira and Leganza since Jan In parallel, the activities of development and production for the 4HP16 automatic transmission with electronic control unit had been done by related parties. The design work started since end of 1994 and finally the mass production of 4HP16 for Nubira 2 was started February Now 4HP16 has been installed for Magnus and Rezzo since December Figure 4: Assembly line Key manufacturing technologies DTL kept key technologies for in-house production like - gear manufacturing - planetary gear set manufacturing - shafts and pump manufacturing - heat treatment - machining of the housings - deep drawing parts (4 HP 16) - assembly - testing Figure 5: Housing transfer line Figure 3: Sub assembly parts Figure 6: Transfer press M/C 3

4 Additionally DTL installed facilities for - die casting and mold making - differential - torque converter Training The main emphasis of the know-how-transfer was placed on the thorough training of Korean engineers and workers, which was mainly carried out at ZF Saarbrücken in the following fields: Production planning Figure 7: Die-casting M/C - working plans - invest planning - machines and processes Quality - supplier quality planning - incoming inspection - SPC - laboratory - measuring shop Figure 8: Die-casting parts Production - assembly - heat treatment - gear manufacturing - die cast machining - stamping - deep drawing - maintenance - service Development At their Pusan factory further key technologies for parts such as the transmission control unit (TCU), pressure regulator and solenoid valve were installed. These were transferred by means of signing contracts with renowned German suppliers like Siemens and Bosch. - testing - design - calibration - software - drawings - bill of materials 4

5 Suppliers The suppliers were involved at the earliest possible phase of both projects. This offered the suppliers the opportunity to contribute their experience and improvements proposals to the development process. This activity allowed ZF and DTL to maximize efforts toward economical and processcompatible production. By regularly assessing the progress of the project, it was possible to detect crucial characteristics of the project at the earliest stage possible and discrepancies could be solved before. Joint visits at many suppliers in Europe and Korea gave both companies a deep understanding and impression about the know how of these suppliers and a confirmed confidence in the quality of the selected suppliers. Materials An important milestone was also the conversion and analysis of equivalent Korean materials into German/European materials. The materials of every part were checked to see whether and which equivalent material could be used. Only in a few cases was it necessary to import European material. Production know-how ZF s traditional production experience & know-how and DTL s production technology from military business since 1973 was excellent harmony. Based on the strong basictechnology for the both companies, ZF recommended European suppliers for the critical machines and DTL also recommended Asian suppliers for most of machines. ZF gave the assistance on the selection. From the beginning stage, the joint meeting were held with selected machine manufacturers. One particular aspect of the co operation was the necessity to take into account the specific manufacturing requirements of DTL. These were directly handled by the respective development departments and optimized in consultation with the production specialists of DTL and ZF. Despite differences in culture and mentality in addition to communication difficulties, the excellent co-operation between DTL and ZF led to a successful end result. Through competence, professionalism and hard work on both sides, any difficulties which arose during the process of technology transfer were overcome. This was a first successful step for a future and close cooperation which will enable DTL as an independent manufacturer of automatic car transmissions. It was shown that a high technology product like an automatic transmission could be transferred successfully between Germany and Korea. NOMENCLATURE ZF: DTL: ZF Getriebe GmbH Daewoo Telecom Ltd. (Former Daewoo Precision Industries) ACKNOWLEDGMENT We would like to express our appreciation to Dr. Siegfried Goll (Vice-chairman of the ZF - group) and Mr. Oh Joon Kwon (President of DTL) for their outstanding support of the common project. Our special thanks are necessary for the engineers and workers of both companies. Without their hard work this project would not be so successful. REFERENCES [1] Bayer, A., 4 HP 20 automatic transmission for cars and small commercial vehicles. Drivesystem technique, Shanghai, June 1998 Language Most of the ZF specifications, drawings and other documents were translated into English. Some typical production documentation which was only available in German was explained and if necessary either translated into English or directly into the Korean language. The language barriers that existed between German and Korean colleagues (English knowledge was at best rudimentary) were overcome through the use of diagrams, sign language, technical dictionaries or simply learning by doing. At the end of each working day a summary meeting was held, during which the coordinators answered any open questions. CONCLUSION 5