Automated grinding cell doubles productivity for cutter manufacturer
Automated grinding cell doubles productivity for cutter manufacturer
Keywords: Robots, Grinding
Two Jones & Shipman cylindrical grinders, in harness with a Kawasaki robot loader, have almost doubled productivity for Sheffleld (UK) based tool manufacturer Universal Drilling and Cutting Equipment (UDCE), on its "Unibor"range of annular cutters.
UDCE manufacture a wide range of engineering products for the engineering,fabrication and construction industries including electro-magnetic drilling systems, broaching cutters, tungsten carbide cutters, industrial cutters and specialised engineering tools.
The transfer to automation started over a year ago, as sales of its market-leading broaching cutters outstripped production. UDCE's problem was how to reduce a "bottleneck" occurring in its cylindrical grinding process,in which three manual machines were each carrying out primary and secondary grinding operations on high-speed steel cylindrical blanks.
Operation "1" called for the machining of a sleeve and two flats at 90 degrees to one another. Operation "2" required the bar to be turned round and gripped from the opposite end and a sleeve machined with a 0.25mm(0.010in) taper.
Taking an initiative from the automotive industry, Manufacturing Director Brian Gascoyne decided that the way forward was through a fully automated grinding cell with automatic loading and "lights-out" CNC grinding operations. Fully supported by Managing Director Vic Archer, Mr Gascoyne went ahead and purchased a combination of a Jones & Shipman Format 15 cylindrical grinder and Kawasaki robot loader.
Initially, manipulating the robot's twin arms into position – to deliver and remove parts from the Format 15's chuck – turned out to be an extremely difficult task. However, after extensive trials, adjustments and re-programming,autoloading was achieved, and with it, considerable improvements in production. As Manufacturing Manager Mick Wood says:
We knew the way forward – however it took us a long time to get it the way we wanted it.
Mr Wood adds:
Once it was fully commissioned, and we saw the productivity benefits from the Format 15 robot loading set-up, we felt that the natural progression would be to carry out both operations simultaneously, through the integration of a second cylindrical grinder into the existing grinding cell.
After lengthy discussions with Jones & Shipman's sales and applications engineers, and a review of several competitors' machines, Mick Wood became convinced that the Jones & Shipman Ultramat CNC cylindncal grinder was the ideal second machine for the grinding cell.
The Ultramat CNC, along with the recently introduced microprocessor-based Ultramat Easy Grind, fit neatly into Jones & Shipman's carefully structured range of cylindrical grinders, combining many of the features of the larger,high production cylindrical grinder, the Supromat, but at a signfficantly lower price (see Plate 2).
Not only is the Ultramat extremely productive but it is also simple-to-use. Easy-to follow Windows® set-up pages allow the operator to digitise diamond and wheel positions and, by a minimum of mouse or softkey/keyboard inputs,produce a finished program.
Plate 2 UDCE's fully automated CNC cylindrical grinding cell featuring a Jones & Shipman Ultramat CNC cylindrical grinder
Graphical images prompt the operator, and spreadsheet style programming ensures quick and simple input. A GE Fanuc CNC Intelligent Terminal, with associated GE Fanuc digital AC servos provide the control. All control equipment is housed in an easily accessible cabinet incorporated into the machine.
Mick Wood says:
The learning curve we had experienced for the single-grinder configuration really helped us define what we required to integrate the Ultramat, in terms of software programs, I/Os and the robot's microprocessor control, with help from both Jones & Shipman and the robot installer.
The GE Fanuc 210i CNC that controls the Ultramat provides an integrated Programmable Machine Control (PMC) that executes the Jones and Shipman machine logic. The carefully designed modular construction of this logic allowed the Jones and Shipman project team, headed by Senior Software Engineer, Alan Fisher,to rapidly introduce a customised auto-loading interface module. Pre-existing modules including auto-guard, in-cycle features, messages, foot-operated automatic tailstock and push-button operated automatic chuck were also identified as requiring modification. The hardware specification for the robot arm, as well as its sequencing and interfacing with the Ultramat, were specified for UDCE by a specialist company. With these modifications in place, the Ultramat literally became a "slave" of the robot.
Now fully productive, the automated grinding cell processes one cutter every minute – the Format 15 carrying out operation 1 and the Ultramat carrying out operation 2 – with fully automatic loading and unloading from the robot loader. With the grinding cell an unqualified success for UDCE, this booming Sheffield company has other areas of production under careful scrutiny to see if they will also lend themselves to the advantages of automation.
For further information contact: Mark Franckel, Sales & Marketing Director, Jones & Shipman International, Narborough Road South, Leicester,LE3 2LF, UK. Tel:+44 (0) 116 289 6222; Fax: +44 (0) 116289 2945; e-mail: mfranckel@js.renold.com
