Clamping device for mounted points
- November 3, 2019
Schunk is expanding its high-precision clamping technology as a standard element of mounted point clamping with Tribos mounted point holders.
Schunk says the Tribos mounted point holders can attain repeat accuracies < 0.01 mm (0.0004 in.). The rotationally symmetric design enables maximum speeds of up to 90,000 rpm. This means that demanding shape and position tolerances can be reliably achieved during internal cylindrical grinding and jig grinding, Schunk says. At the same time, the grinding wheels are evenly worn off and the service lives of the mounted points increase, while mounted point costs decrease accordingly.
Schunk says that Tribos polygonal clamping technology has several advantages compared to conventional toolholders for mounted points. The precision toolholders work without moving parts and are therefore mechanically insensitive. Moreover, it is not necessary to heat or cool down the mountings during the clamping process. The precision holders enable several thousand clamping procedures without material fatigue.
For tool change, by using a clamping device, the mounted point holders can be pressurized with a predefined pressure, meaning the polygonal mounting bore deforms within the permanently elastic region to form a cylinder. In this clamping condition the mounted point can be easily inserted into the holder. As the process moves below the Rp 0.2 per cent yield point, structural changes in the steel can be excluded. Then the external pressure is reduced and due to the elasticity of the material, the inner diameter returns to its original, polygonal shape, and the mounted point is thus clamped in a force-fit way by the residual stress within the steel. The clamping process can be carried out in a process-reliable way at the first go with a few simple steps. Even small clamping diameters can be easily exchanged at any time, Schunk says.
The Tribos mounted point holders are suitable for all common grinding machines and grinding spindles. As a first step, Schunk offers the precision holders for the interface HJND 50 with clamping diameters 3 mm and 4 mm (0.118 and 0.157 in.) in the slim version Tribos mini, as well as clamping diameters with 6 mm, 7 mm and 8 mm (0.236, 0.275 and 0.315 in.) in the robust version of the Tribos-RM. Additional interfaces (HJND 28 and HJND 21) are already planned.