FANUC robot automates gear blank loading

Citation

(1999), "FANUC robot automates gear blank loading", Industrial Robot, Vol. 26 No. 5. https://doi.org/10.1108/ir.1999.04926eaf.005

FANUC robot automates gear blank loading

FANUC robot automates gear blank loading

Keywords Robots, Automotive, Machining

Any production engineer involved with turning appreciates that when it comes to second operation work loading and unloading all too often represents a disproportionately large part of the overall cycle time. All the benefits of the first operation bar feed auto cycles are dissipated on manually loading.

An elegant solution to this problem is the Shimada Indexing Spindle CNC lathe marketed in the UK by Northwich-based Forelink Ltd. This features twin spindles, but not twin spindles in the conventional sense of dividing up the overall first and second operation cycle time between the two spindles (see Plate 4).

Plate 4 The Shimada lathe features auto-loading with a FANUC LR100 robot

On the Shimada both spindles carry out the same second op but these are performed sequentially rather than simultaneously. While one is cutting the other is positioned for load/unloading, thus taking loading operation out of cycle time.

The two spindles are horizontally opposed on a large 580mm diameter curvic coupling that is mounted in the vertical plane. The inner spindle creates, to all intents and purposes, a conventional single spindle lathe served by an 8- or 12-station turret.

The outer spindle is outside the machine guard enclosure and can be accessed for loading. This can be manually or by robot.

Forelink have proved that equipping the Shimada with a FANUC LR100, a bench mounted robot, is a most cost-effective exercise. The LabMate sits comfortably on the machine headstock. Its ability to reach up to 350mm (160mm plus tooling) below the base played an important role in robot selection. The spindle centreline is 330mm below the top of the headstock.

Using a robot in conjunction with pre-loaded pallets of components means that the machine can continue to run unmanned in "lights-out" mode at the end of every shift.

When used to machine gear blanks, the pallets can hold 200 blanks that represent an additional six hours of "free" machined components at the end of each shift.

When the gear blanks were machined in a conventional chucking CNC lathe the cycle time was 2.13 minutes. That is made up of 1.85 minutes of machining times and 0.28 minutes of load/unload time. Also, because operators can be distracted when the machine stops at the end of each cycle, an overall efficiency of only 85 per cent can be achieved.

On the Shimada this is transformed to the original 1.85 minutes of machining time plus 2.8 seconds to index the spindles and an improved loading efficiency rating of 98 per cent.

This adds up to a 12 per cent increase in productivity compared with the operator manually loading the machine. When robot loading is used the operator is released for other work and the additional six hours "free machined parts" per day can be added into the equation.

For details contact Maurice Hanley: FANUC Robotics (UK) Limited, Seven Stars Industrial Estate, Wheler Road, Coventry CV3 4LB. Tel: +44 (0)1203 639669; Fax: +44 (0)1203 304333.