Presstechnology – Machine construktion

The frame rigidity of a forming machine has considerable influence on the deformation of tools, the tool wear and the product quality of the products. Add to that the guide geometry and accuracy of the built-up guide. Elastic deflection of the machine frame and the engine also influence the workpiece accuracy and tool wear.
After Ickert is „the accuracy of the desired degree of approximation to an intended result“ The scale used for „accuracy“, the „best possible“ inaccuracy, that the deviation is between the desired setpoint and the actual value. This causes the selected „tolerance“ is therefore a reliable and agreed deviation of the actual value from the setpoint.

The accuracy behavior of pressing must be interpreted functionally necessary. The structural design of the cross sections, manufacturing steel-welded or cast body and the selection of the engine determine often the quality of the products. Parallelism of toolholders / holes between table and ram. Squareness of the slide movement to the fixed platen. Sufficient rigidity of the machine frame and little variation of the working capacity of the press are the basis to be able to be manufactured economically.
The precision of the slide movement can be determined without load, by notice to the angularity of the ram stroke in-coercive movement. The motion accuracy of the slide under load with zwansgeführten stroke can be determined by means of high-speed camera. The recordings are in debugging often helpful.

To detect the failure of the product and to state clearly whether it be at an inaccuracy of the machine on faulty installation of tools or other reasons, you have an interdisciplinary basis with all departments working on the process and transparent way.  Mechanical presses are used for non-cutting shaping by a straight tool movement. Shaping takes place between the usually solid press frame and the movable press ram. Problems arising from the forming deformation forces acting on the workpiece, the tool and the press, and require correspondingly high counter-forces of the press and the press frame and matching driving forces for the engine.

The drive system most commonly used for mechanical presses is the crank mechanism, used in eccentric, crank and crank presses towing and partly as a basis of Togglepresses. The working capacity of a press is determined by the drive and the flywheel effect size. For trouble-free operation of a mechanical press the working capacity should not be exceeded. With slight presses the press frame is severely stressed and the rigidity is missing. Too big designed machines are not economical in operation.

The accuracy of pressing depends on different factors and influences. The squareness of the ram stroke for fixed platen. Parallelism of the tool receiving surfaces of table and ram. Holes in the tool receiving surfaces must be parallel. Guide play of the plunger in OT 0 °, measure 180 ° at 90 ° and at UT and possibly. Readjust. Too much play in bearings guides has an increased tool wear result. must be noted in measurements during exercise and the deflection of stands and press head piece and the loading of the press by the forming process (tool center-off center, etc.). A „cant Direction follower“ can be caused by the elastic deformation of the guides or by a lateral tilting of the frame.

In the production of workpieces by forming various disturbances / errors occur which are attributable to a faulty machine, a faulty tool, or both. The errors occurring randomly can initially detect any tendency by various influences such as temperature fluctuations, elastic deformations caused by power fluctuations of the drive, differences in input material etc. are the error difficult narrow. When systematic errors a clearly definable trend is evident, for example, Increase in diameter by a compression of the cutting punch. A faulty machine has several negative effects on the workpiece and can e.g. , Offset in part and vertical offset cause concurrency errors.

umformtechnik-pressen