Cylinder head

When it comes to cars, the cylinder head is cast from aluminium alloys. The configuration and features for machining vary according to the engine fuel. The cylinder head is fitted on the cylinder crankcase and is responsible for the fuel and fresh air supply. Due to its stringent requirements for quality and tolerance, it is the most demanding component for machining in engine manufacture. Through precise valve control and minimal friction losses in the camshaft bearings, fuel consumption and emissions are already reduced before the combustion process.
„Cylinder head with valve train, injector bores and camshaft bearing bores structure

Características‑chave

  1. Comando de válvulas
  2. Furo do injetor
  3. Furo no mancal do eixo de comando
  4. Furo do tampão de água

  • The tool carries out the pre-machining of the base bore in the internal combustion engine.

    1. Pré-usinagem – Furo cego

    As altas velocidades de avanço e grandes volumes de cavacos exigem ferramentas para mandrilamento estáveis com ponta de PCD e remoção eficiente de cavacos. A usinagem constitui a base para todas as etapas subsequentes do processo no comando de válvulas.
     

  • The tool carries out the finishing of the blind bore in the internal combustion engine

    2. Usinagem de acabamento – Furo cego

    As ferramentas para mandrilamento com múltiplas arestas de corte e ponta de PCD garantem a precisão dimensional e a qualidade de superfície. A precisão nesta etapa de usinagem essencial para a prensagem subsequente dos anéis de assento da válvula e das guias da válvula.

  • “The tool carries out the pre-machining of the valve seat in the internal combustion engine.”

    3. Pré-usinagem – Assento da válvula e guia da válvula

    Após a prensagem do anel de assento da válvula e da guia da válvula, é realizada a usinagem dos materiais duros. Para isso, são necessárias tolerâncias extremamente rigorosas e materiais
    de corte resistentes ao desgaste.

  • The tool carries out the finishing of the valve seat in the internal combustion engine.

    4. Usinagem de acabamento – Assento da válvula e guia da válvula

    Para superfícies vedantes precisas, são utilizadas ferramentas de furação fina ou mandrilamento de alta precisão, que garantem alta estabilidade do processo e longa quantidade útil da ferramenta.

1. Sistema di distribuzione

CONDIZIONI DI PROCESSO
  • High-precision requirements for form and position tolerance
  • Cylindricity 10 μm 
  • Diameter tolerance 15 μm
  • Coaxiality from valve seat to valve guide
  • Circularities < 8 μm
  • Angle tolerances on the valve seat ring in the μm range
  • Materials with high resistance to wear on valve seat ring
  • Maximum process reliability and accuracy of repetition
PCD fine‑boring tools for machining the valve train pilot bore in the cylinder head

FORO PILOTA

1. Prelavorazione
Utensile di barenatura in PCD
  • Design dell’utensile compatto e stabile per la massima precisione di posizionamento.

2. Lavorazione di finitura
Utensile di barenatura in PCD
  • Concetto di utensile multitagliente per tempi di lavorazione ridotti.

Werkzeuge zur Bearbeitung vom Zylinderkopf: Ventilsitz und Ventilführung

SEDE VALVOLA / GUIDA VALVOLA

3. Prelavorazione
Utensile pilota
  • Utensile corto e stabile, garantisce la massima precisione di posizionamento per il successivo utensile di finitura.

4. Finitura
Utensile di finitura

  • Lavorazione di finitura a elevata accuratezza con bareno di precisione regolabile dotato di sistema EA e alesatore per guida valvola a cambio rapido.

2. Foro dell’iniettore

CONDIZIONI DI PROCESSO
Three tools for machining the cylinder head via the injector bore using a three‑stage process

3-step process for maximum process reliability

1. Pre-machining
PCD multi-stage solid drill
 
  • Multi-blade solid drill and boring tool with brazed PCD inserts and special chip flutes for optimal chip removal.


2. Semi-finishing
Solid carbide step drill

  • Special cutting-edge geometry and spiralisation for the best chip breaking and chip removal.


3. Finishing
PCD step reamer

  • Multi-blade step reamer with brazed PCD inserts, special cutting-edge geometry and expanded chip flutes for optimal chip removal.

Two tools for machining the cylinder head via the injector bore using a two‑stage process

Two-step process for maximum productivity

1. Pre-machining
PCD boring tool with solid carbide drill

  • Maximum usable tool life of PCD inserts due to Drilling from solid stage that can be changed separately.

2. Finishing
PCD step reamer

  • Multi-blade step reamer with brazed PCD inserts and expanded, polished chip flutes for optimal chip removal.

3. Camshaft bearing bore

PROCESS CONDITIONS
  • Cylindricity (15 μm over 100 mm)
  • Circularity < 5 μm
  • Diameter tolerances of 15 – 20 μm
  • Surface qualities of < Rz 5 μm
  • Repeated cutting due to the interrupted cut
  • Tools with very high length–diameter ratio
Large tool, also known as a line boring bar

Maximum productivity with one-shot solution

1. Pre- and finishing machining
Line boring bar
 
  • One-shot machining with very good straightness of the bore due to additional bearings with roller or plain bearings.

Two fine boring tools for machining the internal combustion engine

Ultimate process reliability with 2-step process

1. Pre-machining
Fine boring tool

  • Guided fine boring tool with easy-to-adjust HX indexable inserts.

2. Finishing
Fine boring tool

  • Guided fine boring tool with indexable inserts – with simple blade configuration and additional pre-cutting stage for maximum quality requirements.

4. FORO DEL TAPPO DELL’ACQUA

CONDIZIONI DI PROCESSO
  • Surface quality Ra < 16 μm
  • Circularity 0.05 mm
  • Diameter tolerance H7
  • Positional accuracy
Tool for machining the core plug bore on an internal combustion engine

4. FORO DEL TAPPO DELL’ACQUA

1. Semi-finishing
PCD step boring tool

  • Short, compact tool design for maximum tool stability.