Turbocharger

Exhaust gas turbochargers are used to boost the performance and efficiency of modern combustion engines. The compressed air supply increases efficiency while reducing emissions – a key aspect of current climate strategies. The most stringent requirements for coaxiality and circularity apply at speeds of up to 300,000 rpm. Particularly on the exhaust side (hot side), high-alloyed, abrasive workpiece materials pose extreme requirements for machining tool wear resistance. At high quantities, even small improvements in tool life for each tool lead to significant cost advantages in series production.

Turbocharger housing with connections and flange

Key features

  1. Internal contour machining
  2. Exhaust manifold connection machining
  3. Control pin bore
  4. Turbocharger housing connecting Surface
  5. Shoulder milling of surfaces

1. Turbocharger housing

PROCESS CONDITIONS
  • Highly heat-resistant and ultra-abrasive materials
  • Complex geometries and contours with chamfers, radii and transitions
  • Tight form, position and surface tolerances
  • Interrupted cuts
A Tooltronic tool clamped in a chuck for internal contour machining of a turbocharger

Hot Side

1. Internal contour machining
TOOLTRONIC® tool

  • Flexible machining with an additional machining axis (U axis) with maximum flexibility for contour changes or wear corrections.

A boring tool for machining a turbocharger

2. Exhaust manifold connection machining
Boring tool
 
  • Tool design with adjustable indexable inserts for short processing times.

High-performance reamer for machining the control pin bore on a turbocharger

3. Control pin bore
High-performance reamer
 
  • Tool design with specially arranged inserts for optimal chip removal, including at the highest feeds

NeoMill-16-Face for machining the mounting face on a turbocharger housing

4. Turbocharger housing connecting surface
NeoMill-16-Face
 
  • Maximum number of teeth and indexable inserts with 16 cutting edges for maximum tool lives and low costs per component.

Corner milling cutter with six cutting edges

Shoulder milling of surfaces
NeoMill-4-Corner
 
  • Short, sturdy tool design for maximum stability and specially developed indexable inserts for workpiece materials that are difficult to machine.

2. Impeller / vane wheel

Turbocharger impeller with shaft bore, balancing surfaces and machined blades

Key features

HOT SIDE:


1. Shaft bore 
2. Balancing surface

COLD SIDE:


1.Shaft bore
2. Balancing surface 
3. Vane machining

PROCESS CONDITIONS
  • Workpiece materials that are difficult to machine on the hot side
  • Material fluctuations and alloy differences
  • Complex machining in hard-to-reach places
  • High-precision requirements for radial run-out
  • Surface requirements of Ra < 0.4 μm
On the left a drill and on the right a profile milling cutter for machining the turbocharger impeller

Hot Side

1. Shaft bore
MEGA-Speed-Drill-Titan

  • Special cutting geometry and coating that reduces the formation of built-up edges and optimises chip removal.

2. Balancing Surface
Profile milling cutter
 
  • Multi-blade, coated solid carbide milling cutter, developed for workpiece materials that are difficult to machine.

On the left a solid carbide drill, in the center a PCD corner milling cutter, and on the right three coated form milling cutters for machining the turbocharger impeller

Cold Side

1. Shaft bore
Tritan-Drill-Alu

  • Three-blade solid carbide drill for the highest feeds.
     

2. Balancing Surface
PCD shoulder milling cutter

  • Multi-blade PCD-tipped milling cutter for the longest tool lives.
     

3. Vane machining
Coated form cutters

  • Form cutters adapted to the component contour for roughing, semi-finishing and finishing.