The Toyoda GE4i is available in A and P formats: the P version incorporates a pull-down internal grinding spindle that can produce both single and multiple stepped bores.
Between-centre distance options across the GE4iA and P versions are 500, 1,000, 1,500 and 2,000 mm, with a grinding diameter up to 300 mm. Swing over the table is 320 mm diameter, with a 400 mm option. Standard wheel-head speeds are 30 m/sec with a 3.7 kW motor.
The machine incorporates several new elements in the basic design that reduce the likelihood of dimensional change during the grinding process by some 30%. This is achieved through a new design of bed,which also incorporates an optimised rib layout. Thermal distortion caused by temperature changes in the flow of coolant is also reduced by the creation of strategic ‘flow passaging’ that has the added feature of air spacing between the machine’s isolation cover and the bed to further reduce any thermal effects.
The wheelhead too provides the benefit of a further 30% reduction, achieved provements in ‘heat releasing’ properties and the inclusion of linear scale-contact type sensors.These compensate for thermal displacement and help to control the relative distance and thus positional accuracy of the workpiece to wheelhead,while significantly reducing any processing warm-up time.
