cutting solutions & methodology [Aug 2012]

August 23, 2012 10:41 am

Constant developments in CNC machining technologies have virtually transformed the automotive manufacturing concept in the global market. Enhance productivity, world class quality and superior finish can be achieved through improve machining, alternative process, state-of-the-art automation, tooling equipment and increase use of robots, robotics systems and controls. Various innovative solutions are being offered for machining of engineering components, the same are highlighted here.
Double Head Spindle CNC Turning CentresDouble head spindle CNC turning centres are the most productive cost effective machines for turning operations on chucking jobs like gear blanks, pump parts, fan parts, hubs, break drums, bearing rings, valves, and bushes etc. These machines have two heads facing each other with one main slide (Z-axis and cross slide X-axis). These machines are provided with linear tooling system with up to six tools for each head.
Advantages of Double Head Spindle CNC Turning Centres• No idle time: Resulting in higher productivity• While machining: Saving of machine time & saving loading and unloading time• Two set-ups: Set up 1 & 2 is finished on the same machine, ready to dispatch• Manpower: Saving manpower cost & saving space on shop floor• Linear tooling system: Helps faster positioning of tools compared with turret • One operator can easily operate around 4-6 machines• Precise CNC controlled movement of gripper/loader ensure correct butting & clamping and eliminates rejection• Obtain predictable output because elements like operator exhaustion, clamping error, etc. are eliminated.
TwinturnTwinturn machines are the most productive double spindle machine and the much better option than two independent single spindle machines.
Advantages• Machine with 8 station turret on first side and linear tooling system on second side for optimum production• Most productive double spindle CNC lathe are designed to be operated by single operator• Objectives of developing Twinturn Series CNC two-in-one turning centre’s are:• Maximising output per shop floor space (work envelop of machine is 60-65 per cent of 2 nos. single spindle machines) • Maximising output per skilled operator.
Super Precision CNC Turning CentresThese machines have been specifically designed for the precision hard turning to replace grinding process of hardened components.
Features & Advantages• Hardened jobs can be ‘Finish Hard turned’ to eliminate grinding. Size tolerances within 6 microns and surface finish better than 0.2 Micron Ra achieved. Hard turning is much faster and economical compared to grinding especially where contours or steps are to be made• Most suitable for machining of unhardened jobs where close tolerances are required. For example in case of a bearing size in an aluminium die cast component (tolerance 14 microns), a standard accurate CNC lathe will produce in a tolerance band of around 8-12 microns whereas Micronturn will produce components in tolerance band of 5-7 microns, thereby ensuring excellent Cp & CPK and causing almost zero rejection • The linear scale technology on these machines ensures that there is no ‘size drift’ due to temperature variations or when machine is restarted after an idle period• Most suitable for turning operations requiring highest accuracy and size stability • Excellent repeatability of + 0.7 micron because of linear scale technology • Super precision bearings in spindle assembly• Excellent surface finish ‘passive dampening’ system• Excellent design: Mono-block casting with torque tube design.
Four Spindle CNC Turning CentresFour spindle CNC turning centres are the most productive and cost effective machines in the world for turning operations on chucking jobs like gear blanks, pump parts, fans, hubs, spacers, bearing rings, valves, and bushes etc.
These machines are two heads on each side facing each other. The heads on each side are mounted vertically one above the other, with upper left & right hand heads and lower left & right heads. The left hand upper and lower hands work simultaneously. Similarly the right hand upper and lower head work simultaneously. The left and right hand heads work sequentially in a closed loop.
These machines are provided with “quick change” linear tooling system with up to six tools for each head, i.e. 24 tools per machines.
Features & Advantages• Two Jobs machined simultaneously on one station• While machining is going on one station (two heads), the operator unloads two competed jobs and clamps fresh jobs at the seconds station• Zero idle time (loading/ unloading), resulting in higher productivity• Two set ups available on one machine: 1st setup of two jobs can be completed on one station while the second setup of the two can be completed on the second station• Linear tooling system used on the four spindle machines reduces machining time because of faster positioning of tools compared to a tool turret• Four spindle machines can also be provided with 8-axis for turn milling applications• The machines can be fitted with Gantry Autoloder for automatic job loading, transfer between left & right heads and unloading.
The examples mentioned above highlight the latest design innovations to enhance productivity of CNC machines for producing engineering components.
For more details, contact:Marshall Machines (P) Ltd.C-86, Phase-V, Focal Point, Ludhiana-141010. IndiaPh: +91 161 5012406/2407 E-mail: neha.admin@marshallcnc.comWeb: www.marshallcnc.com