Transcript COLT Design Manual for Cold Forging Dies Case study: variable adjustment of inner diameter (1) Case study: net-shape forging in close tolerances by.

COLT Design Manual for Cold Forging Dies
Case study: variable adjustment of inner diameter (1)
Case study: net-shape forging in close tolerances
by STRECON® VARI-FIT
Example for net-shape forged
spline on hollow steering shaft
Model of a STRECON® VARI-FIT
Established within the GROWTH project GRD1-1999-10748 "Improvement of Service Life and Reliability of Cold Forging Tools
with respect to Fatigue Damage due to Cyclic Plasticity (COLT)", funded by the European Community.
COLT Design Manual for Cold Forging Dies
Case study: variable adjustment of inner diameter (2)
Principle design of a STRECON® VARI-FIT
highest position
 minimum diameter
• Strip-wound container with
carbide winding core
die insert
• Combined radial and axial
prestressing
carbide
winding core
• Change of the inner diameter
of the die by controlled axial
displacement of the die
stripwinding
• Intermediate rings define the
axial position of the die
axial
prestressing
• Quick disassembly and
assembly for rearrangement
of the intermediate rings
intermediate
rings
lowest position
 maximum diameter
Established within the GROWTH project GRD1-1999-10748 "Improvement of Service Life and Reliability of Cold Forging Tools
with respect to Fatigue Damage due to Cyclic Plasticity (COLT)", funded by the European Community.
COLT Design Manual for Cold Forging Dies
Case study: variable adjustment of inner diameter (3)
Variable adjustment of the inner diameter of the die
Example:
die made of high-speed steel:
circa 3 µm diameter change
per 0.1 mm axial displacement
die made of carbide:
circa 2 µm diameter change
per 0.1 mm axial displacement
Inner diameter of
the die insert:
Ø28mm
Die insert
material:
WC or HSS
prestressed by
STRECON®
VARI-FIT
Established within the GROWTH project GRD1-1999-10748 "Improvement of Service Life and Reliability of Cold Forging Tools
with respect to Fatigue Damage due to Cyclic Plasticity (COLT)", funded by the European Community.
COLT Design Manual for Cold Forging Dies
Case study: variable adjustment of inner diameter (4)
Turning
Shortening the
process chain of
manufacturing and
set-up of dies by
STRECON® VARI-FIT
Heat Treatment
Grinding
EDM
Polishing
Coating
Prestress-Assembly
Tool set-up in the press
in case of
conventional
prestressing
systems
in case of
STRECON®
VARI-FIT
Forging and inspection of
samples
no
OK?
no
Serial production
and on-going inspection
no
OK?
no
Established within the GROWTH project GRD1-1999-10748 "Improvement of Service Life and Reliability of Cold Forging Tools
with respect to Fatigue Damage due to Cyclic Plasticity (COLT)", funded by the European Community.