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

核心优势

  1. 气门传动机构
  2. 喷油器内孔
  3. 凸轮轴轴承孔
  4. 水堵孔

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

    1. 粗加工 – 基础孔

    高进给率和大切削量需要配备 加工稳定、高效排屑功能的PCD 阶梯扩孔钻。在配气机构制造
    中，该加工步骤是所有后续工 序的基础。

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

    2. Finishing – blind bore

    Multi-blade, PCD-tipped boring tools ensure dimensional accuracy and surface quality. In this machining step, precision is crucial so that the valve seat rings and valve guides can be pressed in later.

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

    3. Pre-machining – valve seat and valve guide

    Once the valve seat ring and valve guide are pressed in, machining of the hard workpiece materials takes place. Extremely tight tolerances and wear-resistant cutting materials are required.

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

    4. Finishing – valve seat and valve guide

    Fine boring or reaming tools are used for precise sealing surfaces. These ensure high process reliability and long tool lives.

1. Valve train

PROCESS CONDITIONS
  • 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

Blind Bore

1. Pre-machining
PCD boring tool

  • Short and stable tool design for maximum positional accuracy.

2. Finishing
PCD boring tool
 
  • Multi-blade tool concept for short processing times.

Werkzeuge zur Bearbeitung vom Zylinderkopf: Ventilsitz und Ventilführung

Valve Seat / Valve Guide

3. Pre-machining
Pilot tool

  • Short, stable tool ensures maximum positional accuracy for the subsequent finishing tool.

4. Finishing
Finishing tool

  • High-precision fine machining with adjustable fine boring tool with EA system and quick-change valve guide reamer.

2. 喷油器内孔

工艺条件
  • 极大的阶梯跳跃 >10 mm
  • 由于结构部件的轮廓特性导致排屑极其困难
  • 不稳定的铸造状况
  • 表面光洁度要求高达至Rz 4-级
  • 直径公差在 H7范围内
  • 多种轮廓结构设计，具有多个公差要求严苛的 半径和倒角（± 0.1 mm）
Three tools for machining the cylinder head via the injector bore using a three‑stage process

三步工艺流程，确保 最高工艺流程 安全性

1.粗加工
PCD-阶梯实心钻

  • 阶梯实心钻和阶梯扩孔钻，采用钎焊PCD - 切削刃和特殊设计的容屑槽，实现了最佳排屑 效果。

2.半精加工
整体硬质合金阶梯钻头

  • 采用特殊的切削刃几何形状和螺旋槽设计，可 实现最佳断屑和排屑性能。

3.精加工
PCD-阶梯铰刀

  • 多刃阶梯铰刀，采用钎焊PCD-切削刃， 具有特殊的切削刃几何形状以及加大的 容屑槽设计，可实现最佳排屑效果。

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

两步工艺流程，实现最高生产率

1.粗加工
带可更换整体硬质合金钻头的 PCD -阶梯扩孔钻 
  • 通过可单独更换的阶梯实心钻台阶，最大程度延长了PCD-刀具寿命。

2.精加工
PCD-阶梯铰刀

  • 多刃阶梯铰刀，采用钎焊PCD-切削刃和加大的 容屑槽设计，可实现最佳排屑效果。

3. 凸轮轴轴承孔

工艺条件
  • 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. Core plug bore

PROCESS CONDITIONS
  • Qualidade da superfície Ra < 16 µm 
  • Circularidade 0,05 mm 
  • Tolerância de diâmetro H7 
  • Precisão posicional
Tool for machining the core plug bore on an internal combustion engine

Furo do tampão de água

1. Usinagem de semiacabamento
Ferramenta de mandrilamento escalonada PCD

  • Design da ferramenta curto e compacto  para máxima estabilidade.