Using automation to leverage the full potential of machine tools

Automa­tion is one of the most impor­tant ways in which man­u­fac­tur­ing com­pa­nies can raise their pro­duc­tiv­i­ty lev­els and thus remain com­pet­i­tive. And many solu­tions are now eas­i­er to imple­ment today than they were just a few years ago. Fur­ther­more, invest­ments in this seg­ment are now pay­ing for them­selves ever faster. This, in turn, is mak­ing the sys­tems increas­ing­ly attrac­tive for small and medi­um-sized enter­pris­es. METAV 2022, Inter­na­tion­al Exhi­bi­tion for Met­al­work­ing Tech­nolo­gies in Düs­sel­dorf, Ger­many, is reflect­ing the impor­tance of this top­ic by address­ing this dynam­ic devel­op­ment. Experts from exhibit­ing com­pa­nies will be on hand from June 21 to 24 to pro­vide advice and present their dif­fer­ent systems.

Automa­tion can dou­ble sales

Hal­ter CNC Automa­tion B.V. is based in Hoeve­lak­en (Nether­lands) and has pro­duc­tion facil­i­ties in Issum on the Low­er Rhine. It devel­ops and man­u­fac­tures sophis­ti­cat­ed robot­ic load­ing sys­tems that can read­i­ly be con­nect­ed to exist­ing or new CNC machines from dif­fer­ent man­u­fac­tur­ers. The mobile solu­tions, which can also accom­mo­date heavy work­pieces, can be quick­ly repo­si­tioned if nec­es­sary and changed over to a new series in less than five min­utes. The great prac­ti­cal poten­tial which the supplier’s dif­fer­ent automa­tion solu­tions offer is illus­trat­ed by Heinz Knöpfle GmbH, a con­tract man­u­fac­tur­er for turn­ing, turn­ing-milling and milling based in Schwab­mün­den near Augs­burg. The com­pa­ny invest­ed in a Hal­ter CNC automa­tion sys­tem for a CNC turning/milling cen­ter in 2018. The advan­tages of this first robot­ic cell were so impres­sive that the com­pa­ny decid­ed to invest in four fur­ther automa­tion solu­tions from Hal­ter CNC Automa­tion in the past two years, includ­ing one with a load capac­i­ty of up to 70 kg for han­dling heavy work­pieces and long shafts of up to 800 mm in length. These five load­ing sys­tems allowed Heinz Knöpfle to triple its spin­dle hours and repo­si­tion itself as a con­tract man­u­fac­tur­er. The com­pa­ny was thus able not only to take on more orders from exist­ing cus­tomers, but also to attract a num­ber of new cus­tomers, thus dou­bling its sales.

Gantry loader opti­mizes cycle times

Cit­i­zen Machin­ery Europe GmbH has reg­is­tered grow­ing inter­est among the short turn­ing sec­tor in auto­mat­ed lath­es for inserts and fin­ish­ing parts. “The great enthu­si­asm from Japan for one of our series, which includ­ed an inte­grat­ed load­ing sys­tem, gave rise to the idea of equip­ping two of our machine types in the 42 mm and 51 mm diam­e­ter range with a load­ing and unload­ing sys­tem,” reports cer­ti­fied tech­ni­cian and design engi­neer Matthias Schütz. “How­ev­er, large num­bers of cus­tomers dis­like many of the exist­ing solu­tions on the mar­ket which have a robot­ic cell in front of the auto­mat­ic lathe. They offer very lim­it­ed machine acces­si­bil­i­ty and a lot of pri­ma­ry time is lost open­ing the machine door.”

The solu­tion which the design depart­ment of Cit­i­zen Machin­ery Europe devel­oped in coop­er­a­tion with an axle man­u­fac­tur­er was a 2‑axis gantry for load­ing and unload­ing the machines. This allows work­pieces to be picked up with the cor­rect ori­en­ta­tion out­side the machine and fed to spin­dle 1 or 2 as required. A pres­sure spring in the grip­per ensures that the work­piece is pressed firm­ly against the spin­dle stop. The fin­ished work­piece can be removed from the oppo­site spin­dle in the same cycle. This means that the pri­ma­ry process is only briefly inter­rupt­ed once for load­ing and unload­ing. The over­head shut­ter access means that the large oper­a­tor door can remain closed, thus ensur­ing even short­er cycle times. The accu­mu­la­tion sec­tion for unma­chined parts and the dis­charge sec­tion for fin­ished parts are usu­al­ly dimen­sioned specif­i­cal­ly for the rel­e­vant parts. In addi­tion, a stan­dard­ized ver­sion is avail­able for upright work­pieces of sizes up to L = 120 mm x D = 42 mm. The grip­per jaws are man­u­fac­tured using rapid pro­to­typ­ing and can there­fore be made for any work­piece geom­e­try at short notice.

Opti­mized net­work­ing for reli­able processes

Nowa­days, cen­tral CAD/CAM soft­ware needs to be used for the reli­able and effec­tive exe­cu­tion of all process steps in com­plex man­u­fac­tur­ing tasks. “Our solu­tion allows com­pa­nies to car­ry out all the dif­fer­ent tasks in one sin­gle sys­tem. This begins with read­ing in the CAD data and ends with the actu­al pro­cess­ing by the machine,” explains Peter Brambs, Direc­tor of Prod­uct Man­age­ment & Inno­va­tion at Open Mind Tech­nolo­gies AG in Weßling. “Indus­try 4.0 strate­gies which involve net­work­ing and syn­chro­niza­tion can be tak­en care of by our soft­ware via bidi­rec­tion­al data exchange with the con­troller. Basi­cal­ly, the user sends data to the machine where the cor­re­spond­ing process­es are then exe­cut­ed. Con­verse­ly, data is also received from the machine. This exten­sive net­work­ing ulti­mate­ly facil­i­tates real-time syn­chro­niza­tion between the CAM and machine worlds.”

Zero points, tool data and machine para­me­ters can be read out from the con­trol and com­pared with the pro­grammed CAM data. If the data match­es, and the col­li­sion check is clear, the machine starts. The CAM sys­tem can use inte­grat­ed remote access to load, start and stop NC pro­grams on the con­trol. In addi­tion, the pro­gram sequence is syn­chro­nized with the sim­u­la­tion. The sim­u­la­tion there­fore allows the per­son­nel to access real pro­cess­ing sit­u­a­tions in real time. The CAM and machine worlds are thus opti­mal­ly interlinked.

Flex­i­ble robot support

More and more com­pa­nies are strug­gling to find skilled work­ers and are look­ing for solu­tions which can auto­mate sim­ple and monot­o­nous tasks. Machine tool load­ing and mate­r­i­al han­dling are still large­ly per­formed by oper­a­tors, as they require a high degree of flex­i­bil­i­ty. Most orders are for small quan­ti­ties and involve a wide range of vari­ants, ren­der­ing per­ma­nent­ly installed load­ing and/or unload­ing solu­tions unprof­itable in many cas­es. “The biggest chal­lenge with flex­i­ble load­ing is that the basic sit­u­a­tion is so dif­fer­ent for each machine tool. Set-up takes so long that it is often only worth­while for high vol­umes,” says Prof. Chris­t­ian Brech­er, a mem­ber of the board of direc­tors at the Lab­o­ra­to­ry for Machine Tools and Pro­duc­tion Engi­neer­ing (WZL) of RWTH Aachen Uni­ver­si­ty and the Fraun­hofer Insti­tute for Pro­duc­tion Tech­nol­o­gy, and vice pres­i­dent of the WGP (Ger­man Aca­d­e­m­ic Asso­ci­a­tion for Pro­duc­tion Tech­nol­o­gy). “This results part­ly from the fact that each machine has its own set of fea­tures and that many old­er machines in par­tic­u­lar do not lend them­selves read­i­ly for automa­tion. At the same time, there are no man­u­fac­tur­er-inde­pen­dent com­mu­ni­ca­tion stan­dards, based on OPC UA for instance, that enable machine tools and automa­tion sys­tems to be linked flexibly.”

In the “FlexARob” research project, a sys­tem was set up that sig­nif­i­cant­ly sim­pli­fies the set-up and pro­gram­ming process­es by intel­li­gent­ly inte­grat­ing infor­ma­tion from the engi­neer­ing depart­ment. This allows oper­a­tors to per­form the process inde­pen­dent­ly and with­out the need for expert sup­port. The project par­tic­i­pants also devel­oped a method aimed at opti­miz­ing the process and increas­ing its reli­a­bil­i­ty. Here the robot cre­ates a dynam­ic envi­ron­ment mod­el with the help of a cam­era. This ensures that the process runs collision-free. 

Size: around 7,900 char­ac­ters includ­ing blanks

Author: Dag Hei­deck­er, dax­TR – Tech­nik + Redak­tion, Wer­mel­skirchen (www.daxTR.de)

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Trail­blaz­ing software 

The automa­tion of machine tools requires a mod­ern CAD/CAM solu­tion. NC pro­grams must be sent to the machine in a secure man­ner if high effi­cien­cy lev­els are to be achieved. In addi­tion, fur­ther opti­miza­tions are usu­al­ly required. Only then can the full dynamism and poten­tial of mod­ern pro­duc­tion machines be exploit­ed, and non-pro­duc­tive times minimized.