Industrial applications of CNC industrial applications

CNC applications of Undoubtedly the biggest utility location for CNC manipulate, at the gift, is in the discipline of machining. Indeed, it changed into the response to a machining problem that at first gave beginning to the first CNC device. A 3-movement NC milling device becomes efficaciously proven at the Massachusetts Institute of Technology in 1952.

It was advanced because of problems encountered with the complex machining of curved plane components, to close accuracies, on a repeatable basis.

So amazing is they have an impact on of CNC in this region that revolutionary new system gear is being advanced to harness its ability. Machines such as Turning Centres or Machining Centres, which could accomplish a wide variety of machin¬ing operations at an unmarried placing, are commonplace.

Furthermore, the development of this device equipment is realizing exciting new concepts inside how manufacturing itself is being organized.

Machining Cells, Flexible Manufacturing Systems, Integrated Manufacturing are all present-day increasements that have been spawned by the full effect on of CNC.
A traditional CNC machining center is proven in NC, and a CNC turning center is shown in Half of. CNC manage is also being implemented to the more specialized techniques of steel removal, such as grinding and electro-discharge machining (EDM).

A typical CNC machining center is shown in NC and a CNC turning center is shown in.

The CNC control is also being applied to the more specialized techniques of metal removal, such as grinding and electro-discharge machining (EDM).

1 2/1 Fabrication and welding

Close behind machining activities are applications in fabrication and welding. Since CNC is a machine control, and not a machining control, it matters little what the machine is.

For example, by substituting an oxy-acetylene, plasma, or laser cutting head for the machine tool spindle, the result can be an extremely versatile and productive means of cutting plate material. Replacing the cutting head with a welding torch enables CNC fabrication to be achieved. It must be conceded, however, that robotic welding techniques probably represent an even more versatile option in simple welding applications.

Folding and shearing machinery represent other application areas for CNC control in the fabrication field. CNC bending equipment in pipe and tube applications are making a significant impact in areas such as car exhaust pipe manufacture. A variety of intricate bending patterns can be reproduced quickly and accurately making optimum use of material.

1.2/2 Press work

In parallel with, and in support of, developments in CNC fabrication and welding applications, piercing, notching and nibbling applications have now developed under CNC control.

Blanking and piercing are operations carried out on sheet material whereby a suitably shaped punch is pressed through the material under heavy, and often impact, loads. In piercing, the piece of material punched out is scrap, and it is the component that is left.

Nibbling and notching consist of a reciprocating punch that repeatedly “nib­bles” away at the material being fed underneath it. These processes are utilised where holes, or edge contours of a complex shape, are required within sheet material and the production of a suitably shaped punch would be technically or economically impractical.

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Punching apertures and hole patterns is an ideal application for CNC con­trol. It basically only requires precise positioning in two (X and Y) axes. The ability to punch shapes ranging from the most simple to the very complex, utilising just simple standard punches, is very attractive from a production engineering standpoint. Press speeds in ’excess of 100 hits per minute are common. Where a range of punch options is required, automatic punch chang­ing can be provided. Tool turrets comprising 36 punch stations are common. Integral slug conveyors, running continuously, provide an efficient means of removing the punched slugs without interfering with the press operation.

In many cases the computer can also be utilised to produce optimum “nest­ing” patterns for components being blanked from sheet material. Nesting is the term given to the layout of shaped components, within the sheet material area, to give the maximum number of components per sheet.

CNC presswork eliminates the time-consuming operations of sheet layout and drawing interpretation. The operator is thus freed to carry out other functions. Material handling is minimised since, once loaded onto the machine, all component movement (and in many cases removal and stacking) is carried out automatically.

2/3 Inspection and measurement

Machine tools can be made to produce complex components under CNC control. The next logical step is the utilisation of a machine that can check and inspect the same components under CNC control. The basis of dimen­sional measurement or inspection has already been provided in the part program used to manufacture the components.

Three-dimensional coordinate measuring machines (CMMs) are the result. Such machines are not restricted to measuring individual components. Assemblies and sub-assemblies may be measured by probing and thus inspected by comparing the actual dimensions with the required dimensions. The ability to “remember” positions and dimensions, together with the ability to “re-state” datums, make these machines extremely versatile.

Control soft­ware within the machines makes comprehensive information available to the operator via visual display units and printed hardcopy. Desired dimensions, actual dimensions, actual errors and their locations can be provided. Computa­tional facilities can also take into account, and compensate for, any specified tolerances relating to component features. In specific circumstances, results from inspecting a first-off component may be fed back automatically to the machining process, allowing automatic adjustments of cutter path movements.

Most CMMs operate in a stand-alone mode since various problems exist in trying to incorporate them into a flexible machining system. Such problems include:

  • a) The machines are susceptible to vibration.
  • b) Strict environmental control has to be observed to minimise the effects of heat and humidity on dimensional and volumetric changes.Components have to be allowed to reach thermal stability after the heat­ing effects of the machining process.
  • c) Components have to be thoroughly cleaned before passing to the inspec­tion stage. The effects of dirt or swarf can distort the results obtained from the inspection process.

Coordinate measuring machines can also be used for other tasks within the manufacturing system. For example, they can be used for scribing and marking-out operations. Rough castings or forgings can be probed to ensure that the unmachined as-cast or as-forged dimensions provide enough material for subsequent machining. They can also probe for the presence or absence of features such as cored holes. Sheet metal and pattern development layouts can also be accomplished more quickly and accurately on these machines than by other methods.