Selection Examples of Non-contact Gripper Selection example 1 For small workpiece Selection example 2 For large workpiece !Workpiece size: �ｮ100 x Plate thickness 3 mm !Workpiece mass: 300 g !Distance from the workpiece: 1 mm !Supply pressure: 0.2 MPa !Workpiece size: 2200 x 2500 x 0.7 mm !Workpiece mass: 9.7 kg !Distance from the workpiece: 0.8 mm !Supply pressure: 0.3 MPa (1) Check the workpiece and operating conditions. 1) Workpiece size: �ｮ100 x Plate thickness 3 mm Workpiece mass: 300 g 2) Guide: On the top of the workpiece by means of an external stopper Distance from the workpiece: 1 mm 3) Supply pressure: 0.2 MPa (2) Check the lifting force. 1) From the graph (lifting force.distance from the workpiece), check the lifting force at a supply pressure of 0.2 MPa and a 1 mm distance between the workpiece and the non-contact gripper for each size. XT661-2A: 0.8 N XT661-4A: 3.8 N XT661-6A: 5.9 N XT661-8A: 7.5 N XT661-10A: 14.4 N 2) Calculate the temporary lifting force using a safety factor of 2. XT661-2A: F = f x (1/t) = 0.8 x (1/2) = 0.4 N XT661-4A: F = f x (1/t) = 3.8 x (1/2) = 0.9 N XT661-6A: F = f x (1/t) = 5.9 x (1/2) = 2.95 N XT661-8A: F = f x (1/t) = 7.5 x (1/2) = 3.75 N XT661-10A: F = f x (1/t) = 14.4 x (1/2) = 7.2 N 3) Confirm the relationship “temporary lifting force . workpiece mass”. Convert the workpiece mass (g) into a force (N). 300 g → 300 x 9.8/1000 = 2.94 N For a workpiece mass of 300 g (2.94 N) XT661-8A: Temporary lifting force 3.75 N . Workpiece mass 300 g (2.94 N) XT661-10A: Temporary lifting force 7.2 N . Workpiece mass 300 g (2.94 N) In this case, the relationship “temporary lifting force . workpiece mass” is obtained. For this workpiece, select the XT661-8A. The number of grippers to be used is one. (3) Determine the layout of the non-contact grippers. 1) Install the grippers at the center of gravity (center) of the workpiece, and confirm that there is no problem with the balance of the workpiece during lifting. (1) Check the workpiece and operating conditions. 1) Workpiece size: 2200 x 2500 x 0.7 mm Workpiece mass: 9700 g 2) Guide: On the end of the workpiece Distance from the workpiece: 0.8 mm 3) Supply pressure: 0.3 MPa (2) Check the lifting force. 1) From the graph (lifting force.distance from the workpiece), check the lifting force at a supply pressure of 0.3 MPa and a 0.8 mm distance between the workpiece and the non-contact gripper for each size. XT661-10A: 22.4 N 2) Calculate the temporary lifting force using a safety factor of 2. XT661-10A: F = f x (1/t) = 22.4 x (1/2) = 11.2 N 3) Confirm the relationship “temporary lifting force . workpiece mass”. Convert the workpiece mass (g) into a force (N). 9700 g → 9700 x 9.8/1000 = 95.06 N XT661-10A: Temporary lifting force 11.2 N < Workpiece mass 9700 g (95.06 N) In this case, the relationship “temporarily lifting force . workpiece mass” is not obtained, so multiple grippers must be used. Obtain the number of grippers to be used from the following equation. N = (9.8 x W/1000)/(1/F) = (9.8 x 9700/1000)/(1/11.2) = 9 … Rounding up to the nearest higher integer For this workpiece, select the XT661-10A. The number of grippers to be used is nine. (3) Determine the layout of the non-contact grippers. 1) Adequately take into account the center of gravity and deflection of the workpiece, and then install nine non-contact grippers for a well-balanced hold. (* If a deflection occurs, the lifting force will decrease.) 0.2 MPa 0.3 MPa Workpiece 6 Non-contact Gripper Series XT661