Magnetostrictive position sensor for grinder machine and polishing machine
How to achieve 0.1mm repeatability and controll the position of abrasive heads in the workstations of a grinder machine or polisher machine
Magnetostrictive position and pressure sensor for press control in hot forging
With the WPG-A magnetostrictive position sensor and the 40T96 indicator, the machining processes of metal sheet and tube grinding and polishing machines can be managed with highly repeatable positioning control down to 0.1mm.
The position sensor is installed directly in the work area where dust and coolants are not a problem thanks to the IP67 environmental protection degree.
An alarm threshold alert you when the thickness of the wheels is less than a predetermined value.
Overview
- Application criticality: Need 0.1 mm repeatability for the position and thickness control of the abrasive heads in the workstations of a grinding/polishing machine. The sensor has to work in a harsh environment under demanding conditions
- Products: WPG-A Magnetostrictive transducer + 40T96 Indicator/Alarm Unit, 96×48 (1/8 DIN)
- Result: WPG-A enabled the repeatability of 1 mm – thanks to a linearity error ≤ ±0.04% FS and a IP67 protection
The process
This machine consists of several sequential workstations such as the one shown in Figure 1 capable of grinding and polishing metal tubes, bars and flat profiles of various section and length.
Each grinder can be equipped with different units (usually wheels, belt or disc milling cutters) made of different materials (e.g. tynex or steel brushes, cotton or sisal wheels with abrasive solids/pastes).
The type of grinding unit to be used and its material depends on the final result to be obtained (brushing or polishing).
The challenge
The workpiece (usually metal slabs) can have thickness ranging from 0.5 to 300 mm. It is necessary to monitor the positions of the abrasive belts of the different work stations which in addition to having different granularity are positioned at different heights with respect to the workpiece.
Where tynex (patented Dupont material) Synthetic material brushes or sisal (hard cellular strand of fibre) wheels with abrasive pastes are used, the thickness of the abrasive elements must be kept under strict control. Required precision is up to 0.1 mm.
When the thickness goes below a predetermined value, the machine stops, waiting for the abrasive tool to be replaced.
To have a reading as correct as possible, the position transducers are installed directly in the work area where dust and cooling liquids can damage their electronics.
Product benefits
WPG-A Position Transducer
- WPG-A Magnetostrictive transducers with a signal linearity error ≤ ±0,04% FS, gives a highly repeatable positioning control up to 0.1 mm
- The IP67 environmental protection degree gives optimal working conditions even in the direct presence of dust and liquids
40T96 Indicator
- Indicator with universal input, 4-digit configurable display
- Optionally offers up to 4 alarm output, retransmission and transmitter power supply
Solution
Position and thickness control of the abrasive heads
WPG-A Position Transducers – Up to 10 nos
- Slide cursor axial joint
- Transducer stroke: 300mm (350 for the positioning of the working table), low profile in aluminium
- Reading resolution: 0,5 𝜇m
- Signal linearity: 0,04 % FS
- Protection level: IP67
Supporting Indicator cum Alarm unit
40T96, 96×48 (1/8 DIN) Indicator – Up to 6 nos
- Analog input 0-10Vdc from WPG-A sensor
- Configurable sampling time from 150ms to 15ms
- 4 independent digital output alarm
- 0-20mA / 0-10Vdc retransmission
- Modbus serial communication
Gives out an alarm threshold when the thickness of the wheels is below a predetermined value.
