Development of an automotive engine bracket in ADI.

Transcription

1 First European ADI Promotion Conference 19 th / 20 th April,, 1999 Hanover Development of an automotive engine bracket in ADI. 1 Denis Rousière - R.. & D. Department - A.T. systèmes - Boulogne Billancourt - France

2 Origin of the project... Acoustic engineering concerns with an aluminium Indirect Squeeze Casting bracket solution. c A.T. systèmes general Research and Development project for ADI material. 2 A.T. systèmes - R. & D. Department - Boulogne -Billancourt - France

3 Objective of the project... To solve the acoustic problem with the help of an iron material solution. To find a solution which allows to keep the same range of weight. Better or normal market price. 3

4 Casting functional specifications... Courtesy Renault Diesel motored Laguna car. Courtesy Renault Casting position in the engine Engine Block Bracket Car frame Link rod 4 A.T. systèmes - R. & D. Department - Boulogne Billancourt France

5 Bracket functions (2)... Transmission shaft bearing Courtesy Renault Engineering functional drawing. 5

6 ADI solution proposal... Due to its remarkable mechanical characteristics, the only nodular iron proposed was Austempered Ductile Iron. It has been decided to validate the ADI solution. The casting conception has been first calculated according to the respective materials elastic limits. Here below, the CAD view of proposed design in ADI : 6

7 Automobile engine bracket in ADI Materials characteristics comparison... ALUMINIUM ADI AS7G03 T6 ASTM DENSITY g/cm TENSILE STRENGHT MPa ELASTIC LIMIT MPa ELONGATION % YOUNG MODULUS MPa FATIGUE TEST MPa HARDNESS HB

8 Development results... On the manufacturing process... Metallurgy. Foundry rapid prototyping. ADI heat treatment. Machining. On the technical specifications... Acoustic response. Weight. 8

9 Metallurgy... Chemical analysis : C Si Mn Cu Ni Mo % Micrographic examination : Ausferritic structure with 25 % of stable residual austenite. Courtesy Inasmet 9

10 Foundry rapid prototyping... L.O.M. processs : L.O.M. paper model : 10 A.T. systèmes -R. & D. Department - Boulogne Billancourt - France

11 ADI heat treatment... Heat treatment principle : Temperature Time Austenitizing : 900 C 1 H 20 mn Ausferritizing 385 C 1 H 30 mn Heat treatment cycle : Temperature C 900 C PERLITIC AREA 385 C AUSFFERITC AREA 1 H 2 H 3 H Time 11

12 Machining experience... THREADING DRILLING MILLING Courtesy LAMAT Brinell Hardness from 316 to 321. MACHINING PROCESS : Werner TC500 machining station : 15 kw. High water pressure. Cutting Speed (T/mn) DRILLING 1700 MILLING 400 THREADING

13 Acoustic calculations... Calculation meshing 13

14 Acoustic response... (Target : between 750 and 1000 Hz) Design optimisation VERSION 1 VERSION 2 Ribs First acoustic mode 776 Hz 988 Hz Distortion energy for final design : 14

15 Weight result... Spacing and volume comparison : Aluminium ADI 370 cm3 160 cm3 Weight result : ADI Kg Aluminium Kg 15

16 Conclusion : ADI solution performance... A.D.I Aluminium AS7G03 ALUMINIUM A.D.I. AS7G03 Y93 ASTM Indirect Squeeze Casting Resin Sand CASTING VOLUME 370 cm3 160 cm3 WEIGHT (Machined) Kg Kg ACOUSTIC RESULT Reference Better 16