Chipbreakers – needs, principles and types of chipbreakers
Necessity and purpose of chip breaking
Chip cracking principles
In terms of convenience and safety, short-length closed coil chips and half-turn coma chips are ideal for high-speed machining of ductile metals and alloys.
Chip breaking principles and methods are generally classified as follows:
• Self-break
This is done without using a separate chipbreaker as an accessory or an additional geometric modification of the tool.
• Forced chip breaking by additional tool features or geometric devices.
Principle of forced chip breaking (embedded type)Chipbreakers are basically of two types:
• Built-in type
Built-in circuit breakers are in the form of a step or groove on the slope surface near the cutting edges of the tools. These chip breakers are provided
- After manufacturing – in the case of HSS tools such as drills, milling cutters, broaches, etc. and brazed carbide inserts
- During their manufacture by the powder metallurgical process – for example, disposable inserts made of carbides, ceramics and cermets.
The basic principle of forced chip breaking is shown schematically in Fig. When the strain-hardened and brittle chip reaches the heel, the cantilever chip is forcibly bent and then breaks.
- Fixed type chipbreaker
Fixed-type chipbreakers basically work on the principle of stepped-type chipbreakers, but have the possibility of varying the step width and/or heel angle.
Fixed types of chipbreakersThe figure schematically shows three of these chip breakers in common use:
• With fixed additional sash distance and angle – effective only for a limited parametric combination domain
• With variable width (W) only – not very versatile
