September 2015 saw Citizen Machinery UK (01923 691500) unveil three machines at an Open House event at its Bushey, Herts, headquarters, ahead of their appearance at the EMO exhibition in Milan.
The UK event follows hard on the heels of a major Japanese in-house exhibition CFA85 (Citizen Factory Automation 85) at Citizen Machinery’s headquarters in Karuizawa that witnessed a number of innovative developments (see Citizen Machinery supplement in weblinks below).
At the UK Open House, which was attended by almost 200 industrialists and scored 12 orders worth £1.6 million, the new models took in two Citizen Cincom L series sliding-head machines and one Miyano BNJ series model, with star billing given to the redesigned Citizen Cincom L32 range, which can optionally take bar up to 38 mm.
The L series is the leading Citizen Cincom model range by volume and the L32 model is initially available in three versions – L32-Vlll, L32-X, and L32-Xll.
Common elements across all models include: 8,000 rpm, 7.5 kW main spindle; 8,000 rpm 3.7 kW sub-spindle; 32 m/min on all axes, except Y2 (24 m/min); front and back drilling units offer up to 6,000 rpm from 1 kW motors; gang drilling units offer up to 6,000 rpm from 1 kW motors; maximum front drilling diameter is 12 mm, as is the maximum tapping diameter; and maximum back drilling diameter is 10 mm, as is the maximum tapping diameter. Both bush and non-guide bush operation are possible for each model, with the changeover said to take less than 30 minutes. Ergonomically speaking, access to the machines has been improved via a wider opening operator door.
Taking the models in order, the L32-Vlll, demonstrated at the Open House and then at EMO, can employ up to 30 tools: six gang turning tools on the X1-Y1 unit; four to six gang rotary tools on the same unit; four to nine front drilling tools (X1-Y1 slide unit plus opposite tool post); and five to 11 back drilling tools (X1-Y1 slide unit plus back tool post) to serve the sub-spindle. Rotary tools are an option on both opposite (up to three) and back tool post (up to four). Maximum protrusion length from the main spindle is 150 mm and from the sub-spindle the figure is 80 mm.
The L32-X can employ up to 36 tools: six gang turning tools on X1-Y1; seven to 11 gang rotary tools on the same unit; four to 14 front drilling tools; and nine to 15 back drilling tools (includes rotary tools as standard). Rotary tools are an option on the opposite tool post (up to three). Maximum protrusion length from the main spindle is 140 mm and from the sub-spindle is 65 mm.
The top-of-the-range L32-XII can sport up to 40 tools and is the only model of the three to offer B-axis capability, which operates from the X1-Y1 slide unit, providing +90 to -45° of movement to the four double-ended driven tools (four each to work on the main spindle and sub-spindle).
Apart from this B-axis, the machine boasts: six gang turning tools on X1-Y1; seven to 11 gang rotary tools on the same unit; four to nine front drilling tools; and 13 to 19 back drilling tools (includes rotary tools as standard), supported by Y2 axis on the back tool post. Rotary tools on the opposite tool post are an option (up to three).
Underlying this new range is the adoption of a modular design approach that most visibly demonstrates itself in the functional modules that are available for mounting on the gang, opposite and back tool posts. For example, rotary tools on the gang tool post are supported by three modules – U30B that boasts four rotary positions; U31B that similarly supports four rotary tools, but which also offers manual angle adjustment in the range 0-90°; and the U32B B-axis module as previously described.
On the opposite tool post, there is a choice of packages, with the U150B module boasting four fixed tools (Type Vlll) or U121B with three driven tools (Type X and Xll). The back tool post has two options: U151B having four driven and one fixed tool position or, when incorporating the Y2 axis, U12B can also accommodate nine double-decked tools, four fixed or driven in the upper row and five fixed in the lower row.
With high unattended running now common with Citizen Cincom CNC sliding-head machines, an integrated component unloading conveyor can be optionally fitted in combination with a long part device.
In addition, and as part of the Citizen Cincom control software and following the company’s ECO strategy, power consumption can be viewed for individual workpieces.
SMALLER MODEL IS MODULAR, TOO
The 20 mm bar diameter L20 Citizen Cincom similarly sports this modular approach across three models of the same suffix. Maximum tools for the VIII, X and XII models are 37, 44 and 40. B-axis features on the XII unit, with Y2-axis this time moving the sub-spindle vertically; a feature of models X and XII. There are two, five and three modules for the gang, opposite and back tool posts, respectively. The L20-X was the Open House/EMO machine.
The Miyano BNJ-SY6 fixed-head, twin-spindle, twin-turret, turn-mill centres, representing the sixth generation of the BNJ range, are marked out by their higher rigidity spindles, higher torque rating for driven tools and a new design of eight-station second turret that now incorporates driven tool capability.
Available in two versions of 42 mm (BNJ-42SY6) and 51 mm (BNJ-51SY6) these bar/6-in power chuck machines provide flexibility through overlap machining, with simultaneous machining via both turrets at either spindle a possibility, so machining cycles can be balanced for maximum efficiency. With driven tools on the second turret, flexibility and capability have been extended.
Key features are: 15 kW, 5,000 rpm main spindle; 7.5 kW, 5,000 rpm sub-spindle; 25 Nm, 2.2 kW, 6,000 rpm driven tools on the main turret; 10 Nm, 0.75 kW, 3,000 rpm driven tools on the second turret.
Box item
Laser cutting on a CNC sliding-head lathe
Not present at the Open House but the subject of a video presentation was what is believed to be a world first – laser cutting of a medical stent on a Citizen Cincom L20E sliding-head CNC lathe.
The technology can produce burr-free holes as small as 0.2 mm diameter, features such as spiral cuts with 0.025 mm kerf width and consistent and accurate radii of less than 0.1 mm in corners of slots without any risk of tool wear or breakage are key capabilities of this technology. And these can be produced at a far faster rate than can, for instance, be achieved by a separate EDM process.
Due for European launch in 2016, the Citizen Cincom breakthrough will allow new design concepts, in particular in sectors such as medical, electronic and micro-machining, to be applied.
Shown in the flesh at the Citizen Machinery CFA85 in-house event, a nitrogen gas-assisted 1.5 kW laser head with an air purge to seal and clear the lens was mounted to the gang tool slide of a Citizen L20E machine, with a demonstration part (below) produced in a single cycle. (Different types of laser can be used, such as fibre laser and CO2, with the selection based on workpiece material and thickness.)
Stainless steel tube (304) was fed through a special bar feed unit that allowed standard soluble oil coolant to be pumped at 70 bar through the bore of the material. This ensured cool cutting conditions, washed away any melted material and localised the laser beam to the 1 mm wall thickness of the component as it was fed at a cutting rate of between 300 and 400 mm/min.
Produced from 10 mm diameter tube, the part was turned, faced and three flats milled equi-spaced half-way down its length. The laser then produced along and around the periphery, using C-axis rotation, a series of diamond-shaped features, a bayonet fitting at the front end, cut a complex logo plus a series of holes as fine as 0.12 mm diameter and a number of slots and apertures. The latter effectively created two parts that were interlocked and supported relative axial movement.
This article was first published in the October 2015 edition of Machinery magazine.
