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EIGHTH INTERNATIONAL ALUMINUM EXTRUSION TECHNOLOGY

SEMINAR AND EXPOSITION

Front-loading Technology With

Tandem Cylinder Design For High

Precision Extrusions Tecalex

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INDEX

1. Introduction

2. Front loading principle

3. Advantages of front loading

4. Specific features of front loading

5. Tandem cylinder design

6. Advantages of the Tandem cylinder design

7. Conclusions

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Introduction

• Front loading = charging of billet between stem and die and then moving container over billet.

• Advantages but as well: problems that had to be resolved.

• Tandem cylinder design = 2 pistons (main + auxiliary) on the same axis.

• Precise extrusions + surface quality.

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General press design

• 1100 – 2800 MT

• Front loading + tandem cylinder

• Variable hydraulic flow

• Rotational die changer

• Lubricated butt shear

• Forged front plate

• (…)

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Front loading principle Step 1: Hot shear cuts billet

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Front loading principle Step 2: Billet lubrication

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Front loading principle Step 3: Move billet to waiting position

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Front loading principle Step 4: Container and stem move backwards

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Front loading principle Step 5: Butt shear removes butt

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Front loading principle Step 6: Move billet to extrusion axis

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Front loading principle Step 7: Clamp billet between die and stem

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Front loading principle Step 8: Close container and extrude

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Advantages of front loading Comparison back loading vs. front loading

• Compact design with

50% less cylinder

stroke

• Reduced dead cycle

times

• No need of high speed

movements

• Less oil volume

Back loading

Front loading

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Advantages of front loading Symmetrical upsetting of billet

Front loading

Back loading

• Front loaded billet in the

center line = no

perpendicular stresses.

• Less clearance between

container and billet.

• Symmetrical billet

deformation, no press

bending or die uplift.

• Higher precision of the

extruded profile.

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Special features of front loading Loading 2 pieces is tricky !

2-piece billet waiting Clamping 2 piece billet

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Special features of front loading Optimized warm shear to remain original section .

• 2-piece billet from billet rest management is easy to load

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Special features of front loading Feeder with movable shell to support different billet length.

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Tandem cylinder design 2 pistons (main + auxiliary) working on the same axis.

Main Piston

(Forged Steel F125)

Auxiliary Piston

(Forged Steel F125)

Billet clamp

Pre-fill valves

Shaft

(Forged Steel F125)

Nut

Bushing

Bodies

(Forget steel St52.3)

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Tandem cylinder design Video clip: Working principle.

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Advantages of Tandem Cylinder Forged steel plate flexion: Finite element analysis.

0,253 0,222 0,19 0,158 0,126

• Two cylinders on the main axis

= reduced cylinder diameter and

reduced front plate dimensions

and distance of tie rods,

compared to conventional

cylinder design.

• Due to the less distance

between the tie rods, a tandem

system press has 24% less

flexion than standard presses.

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Advantages of Tandem Cylinder Alignment of the stem.

• The additional bearing points from the auxiliary cylinder improve

the alignment of the stem = more precise stem movement = more

precise extrusion.

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Conclusions

The combination of front-loading technology with tandem

cylinder design helps to improve the precision and

surface quality of extrusions because:

• Front loading = The billet is loaded exactly and

symmetrically onto the extrusion axis.

• Due to the tandem design, the bending of the front plate

is reduced and the die movement as well.

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Thank you for your attention!

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