Position sensor for automatic welding machine for flat steel
Discover how to achieve synchronous lifting of metal plates with position sensor and transmitters on automatic welding machines
Accurate measurement and control of oil pressure in the hydraulic circuit and the position of the arms are essential in automatic welding machines.
These performances can only be achieved with:
- the position transducers and magnetostrictive pressure transmitters WRG-A, which guarantee high linearity and repeatability in detecting the position of the machine arms that must be operated in a precise and synchronous way
- the KS transmitter guarantees an accurate and stable pressure measurement of the hydraulic circuit.
Overview
- Product: WRG-A magnetostrictives transducer – 1250 mm stroke – inside cylinder mounting
- Customer request: maximum 4,5 millimetres error tolerance in the control of 15 independent lifting arms of large metal slabs welding machine.
- Achievement: WRG-A has enabled the synchronised lifting with error tolerance of about 1,5 millimeter.
The process
The purpose of the machine is the welding of metal slabs.
A feeding system on rollers brings two large metal slabs under the two opposing TIG welding units.
The process consists of lifting the two metal slabs and then welding a tangential plate along its entire length.
The challenge
In the specific case, because the large size of the two slabs, 15 independent lifting and positioning arms are required, operated by hydraulic cylinders controlled via proportional valves.
The challenge is the synchronous lifting of the metal slabs, to avoid the distortions of the slabs or penalizing the weight of some arms compared to others that are not at the same height.
Accurate measurement and control of oil pressure in hydraulic circuit and position of the arms are very critical to this application and it can be achieved only with position transducers and pressure transmitters which offers very high accuracy and repeatability.
Product benefits
- WRG-A magnetostrictives transducers with high linearity and repeatability are the ideal products to coordinate machine parts that need to be moved precisely and synchronously.
- It provides the position feedback of moving part in almost real time – thanks to response time of 1 millisecond.
- High accuracy and fast response time KS transmitter provides a perfect pressure measurement of the hydraulic circuit.
Solution
- Position control of the lifting arm
- Position Transducers WRG-A (Mounted inside the cylinders) : 15 nos.
- Working Pressure : 220 bar (Max allowed range 350 bar)
- Rod diameter : 10 mm
- Transducer stroke : 1250 mm, rod body AISI 316
- Signal linearity : 0.04 % of FS
- Output signal : 0-10 V
- Pressure Transducer KS for oil pressure measurement of hydraulic circuit
