Product category:
CNC turning centres, mill/turning, multi-tasking centres, horizontal and VTLs.
News Release from: NCMT | Subject: Okuma and Howa 2SP-V55 twin-spindle VTL
Edited by the Manufacturingtalk Editorial
Team on 27 February 2004
Twin-spindle VTLs machine knuckles
accurately
Weight and eccentricity of automotive knuckles determined they had to be machined in a vertical turning lathe cell to reliably achieve the close machining accuracies required.
When Coventry-based King Automotive Systems won a seven-year contract to produce the front left- and right-hand knuckles for the latest Range Rover, it needed to invest in vertical turning, as the 11kg components were too heavy for the company's horizontal-spindle lathes So at the beginning of 2002, an Okuma and Howa 2SP-V55 twin-spindle vertical turning lathe (VTL) supplied by NCMT was installed opposite a pre-existing, horizontal machining centre to form a knuckle production cell
This article was originally published on Manufacturingtalk on 22 May 2001 at 8.00am (UK)
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Said Kevin Jones, Engineering Manager at King Automotive, "The weight of these components combined with their eccentricity makes them difficult to turn to within the required +/-15 microns.
"A principal requirement for the VTL was therefore robustness, which was part of the reason we chose the 19 tonne Okuma and Howa.
The twin-spindle lathe turns left and right knuckles simultaneously over three shifts, seven days a week, producing 150 pairs a day well within tolerance." Painted steel knuckle forgings are delivered by a local supplier.
Handed components are set up by the operator in bespoke fixtures in the two vertical spindles and the components undergo mirror-image operations, as follows.
First, a centraliser mounted in the 12-station tool turret moves in to ensure that the part is fixtured correctly, followed by rough turning of the datum and back bores.
Next, a combination tool finishes the top of the datum bore with one indexable insert and a second insert turns an internal groove.
Finally, the back bore and the bottom of the datum bore are finish turned.
Operations on the twin-pallet, horizontal machining centre, on which four knuckles are fixtured per pallet, involve milling all faces, removal of the calliper and strut using gang milling cutters, drilling four holes and boring to size.
Specification of the Okuma and Howa 2SP-V55 twin-spindle VTL include maximum turning diameter and length of 550mm and 635mm respectively, 800mm distance between spindles, turning speeds up to 2,000 rpm delivered by 18.5/22kW drives, 20m/min rapids and a Fanuc CNC system for four-axis simultaneous control. Request a free brochure from NCMT ...
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