Broaching Machines by Karl Klink
Looked at with regard to kinematics, broaching machines are relatively simple machine tools. In their basic form, they must perform a relative movement in a straight line from tool to workpiece in the form of the broaching stroke.
Broaching machines are differentiated in their structure as follows:
- Surface and internal broaching machines (type of broaching method)
- Vertical and horizontal broaching machines (position of the main axis)
- Hydraulic and electro-mechanical broaching machines (type of main drive)
- Special broaching machines (e.g. pot broaching machines, chain broaching machines
- Low surface area requirement
- No sagging of the broaching tool caused by its own weight
- Better effect of the coolant
- Simple integration into production lines
- Low installation height
- Long stroke lengths
- Easier infeed of heavy workpieces
- No pit foundations or operating pedestal
The controllers of broaching machines are mainly PLC-based due to the relatively simple kinematics.
Broaching tasks such as helical broaching, which typically combine complex kinematics with the demand for high flexibility in adapting to new workpiece profiles, are today being performed using the latest digital CNC technology.
The following is a comparison of the drive-related advantages of hydraulic and electro-mechanical solutions.
- High dynamics
- Increased dynamics and reduced electrical connected load can be achieved with a pressure accumulator
- Lower investment costs
- A lower long-term cost risk in maintenance
- High rigidity
- High linearity (for CNC operation)
- Lower sound pressure level thanks to less of a tendency to vibrate
- Lower energy costs
- Low space requirement
- More environmentally friendly
With regard to the influence on the broaching process, there is no clear preference between one or the other drive type, although in the case of hydraulically driven machines people talk about a certain damping behaviour that many users prefer.