Multiple clamps MU 7 have been developed for clamping of semi-products on vertical and horizontal machining centers, and their application may be even more varied. They enable to clamp on 3 mm in hard jaws, and in comparison with standard vices, it is possible to clamp more workpieces and to make a better use of the machine space. The scope of application is widened by soft jaws, in which any shape or recess, countersink, etc. can be milled. There is no necessity of creating a one-shot fixture for each untypical product, which is usually very expensive. Using the MU 7 clamps, it is possible to achieve remarkable savings of costs of starting a new production.
The clamps consist of a bar, end (marginal) modules, clamping modules, and exchangeable jaws. Thus the clamping is carried out in a sequential series, each clamping nest, at the same time, constitutes a fixed jaw for another part on the bar. At the screw loosening, the clamping module moves back to the initial position by means of integrated springs. A locking step is 3 mm and the clamping stroke is 6 mm, which enables to clamp even inaccurate (varied) dimensions, castings, or forgings.
The hard jaws are used to clamp on 3 mm. This saves costs of material, as no large technological allowances are needed anymore. But the main advantage is that the workpiece can be machined on all sides at one clamp, it holds a small edge. How is it possible that the clamp holds the semi-product safely on 3 mm only? The reason is simple. By clamping by means of a wedge it is possible to develop a high clamping force.
The high clamping force is of course good for nothing if the workpiece holds in the clamp only due to friction, as it is with standard vices. Due to the teeth, which the MU 7 hard jaws are provided with, however, the jaw teeth bite into the semi-product, and through this mutual touch of the materials they hold the semi-product reliably. That is why it is possible to use even exacting roughing aplicatons, without risk of tearing the workpiece off the clamp. In modern CNC machining when we always try to carry out as many operations as possible at one clamping - for the part accuracy and of course because of savings of side time – the clamping into hard teeth is of enormous importance. Conventional methods of clamping cannot guarantee comparable rigidity of clamping in all directions, even though they are multiplied by hydraulic, pneumatic, or mechanical booster. Multiple clamping is not used only for clamping of tiny workpieces.
This is visible from the enclosed pictures, where the workpiece dimensioned 320x220x130 made of heat-treated steel is clamped into two bars of the multiple clamping on 3 mm only. As this is machining on a five axial machine, the clamping requirements are remarkably high. Not only must the clamp hold the workpiece with regard to the forces acting in the machining processes, but they must also carry the workpiece weight in various swivelled positions.
The clamping bars and jaws are of the same width of 77 mm. The clamping bar length is 480 mm as standard, because they are mostly clamped in the direction of Y axis of the machines, which mostly have the table of width 480 - 500 mm. Nevertheless, we can also produce other clamping bar lengths on order (up to 600 mm). On the clamping bar of the standard length (480 mm) up to 4 products can be clamped (dependent on the dimensions clamped). It has proved as convenient to clamp the bars by means of base plates (pallets), which can be tailor-made for the machine type. In this way it is really possible to make use of the whole size of the machining center table, as more bars can be located in accurate pitches throughout the machine work space
The base plate thus facilitates the technological preparation and, in addition, it can be well used when clamping larger parts with several clamps. A typical example is the clamping of a long thin bar, which would vibrate if there was a larger gap between the clamps. The base plate can be tailor-made for your machine. The KASTR MU 7 multiple clamp is just a well-usable device for clamping. The idea how and when to use it, and thus to make setting and production time more productive, must come from a thoughtful person every time. It is universal and enables a quick re-setting of the clamped dimension. It is not possible to clamp everything and under any circumstances, but you can use it everywhere its advantages can be utilized.Copyright © 2014 Kastr