BookTitleMAGNET_GENERAL_CATALOG

Summary

MAGNET_GENERAL_CATALOG

Magnetic ChucksThe holding power varies largely depending on the type of magnetic chucks andmaterial, thickness and attractive area of workpieces and distribution of mass andsurface roughness of the attractive face of workpieces. The following graphs showtypical examples; you can refer to them for tendency. Please note, however, thatvalues differ slightly among chucks. Always locate workpieces in such a mannerthat the holding area is positioned over both the N and S poles.There is no absolute rule for selection of pitches suitable for workpieces. Ageneral guide, however, is that the best condition for holding is that the thicknessof workpieces is 2 to 4 times the pitch.To attract a workpiece firmly, it should be placed over the N pole and S pole, andaccordingly, the attractive face of workpieces must at least be 3 times the pitch.The separator part of the chuck work faces is made of brass, resin, etc. Selectgrinding fluid that does not corrode these materials. For details, please consultwith grinding fluid suppliers.Light dutycutting　Heavy dutygrinding　■An example of construction of rectangular electromagnetic chuck ■An example of construction of rectangular permanent magnetic chuckHolding Power of Magnetic ChucksSelection of grinding fluid※Use the Facsimile Communication Form (Selection Data)　at the end.Holding Power and Pitch between Poles■Standards Standards of electromagnetic chucksThe holding power on the chuck face plate must be 98.1 N (10 kgf) or over in average and 49 N (5 kgf) or over in the weakest area.Dielectric breakdown between the charged part and the body is not allowed. (1500 VAC, 1 min.)The insulation resistance must be 5 ΩM or over. (Measured with 500 V insulation resistance tester)The temperature rise on the chuck work face must be below 15℁E (Powered on for 3 hours)When a chuck is immersed in water, no water must enter the inside or its insulation performance must not drop.Up to 3000.010.02Over 300 up to 6000.0150.03Over 600 up to 9000.020.04Over 9000.0250.05Surface roughness: 6.3SMounting face: Not convex.�E�Em�E�Note: The standards for the holding power and temperature rise vary depending on models.KETZKETKETNKESLEP-QEPTRMWH・RMCWRMWH・RMCWRTHRMT・RMCRMARTHTest piece thickness 25 mm, SS400 ground surface Test piece 50 ÁE50 mm, SS400 ground surfaceAttractive area of test piece Thickness of test piece●Relation between attractive area ofworkpiece and holding powerRelation between thickness of　 workpiece and holding power■An example of holding power <>　�E�EN≁E.1kgf�E�●　�E�E/cm2�E�E�E�E�E�E00050004000300020001000�E�Em2�E�E0 10 20 30�E�Em�E�E550751001251500 200 400 600Holding powerHolding power per unit areaKETZKET・KECKETNBodyCoil Face plateIron coreSeparator Waterproof layerBase plateIron coreFace plateMagnetic pole SeparatorMagnetCaseTest piece 50 ÁE50 mm, SS400 ground surface Test piece 50 ÁE50 mm, SS400 ground surface■An example of holding power <>　�E�EN≁E.1kgf�E�Thickness of test piece Thickness of test piece●Relation between thickness of workpiece and holding power�E�E�E�E005004003002001001.0 2.0 3.0�E�Em�E�E�E�E�E�E00025002000150010005000 10 20 30�E�Em�E�Max. holding powerMax. holding powerTest piece 50 ÁE50 mm, SS400 ground surface■An example of holding power <>　�E�EN≁E.1kgf�E�Thickness of test piece●Relation between thickness of workpiece and holding power�E�E�E�E00025002000150010005000 10 20 30�E�Em�E�Max. holding power0 25 50 75 100�E�！E��SS400SUS430S45CS45C hardenedSKH2SKH2 hardenedFC400FC2000 25 50 75 100�E�！E��SS400　 ▽▽▽ GSS400　 ▽▽SS400　 ▽SS400　 �E�●Difference in holding power due to　materials (%)■Relation between material and holding power<>●Difference in holding power due to　attractive surface roughness (%)　Length or diameter of face plateFlatnessParallelismHolding powerWithstand voltageInsulation resistanceTemperature riseWater resistancefriendlyEnvironmentallyThese magnetic chucks employ special resin forbonding attractive face structural members,instead of solder that is normally used, but is anenvironmentally hazardous substance.The quality standards of electromagneticchucks have been establishedas described in the right-sidetable for dimensional accuracy( f l a t n e s s / p a r a l l e l i s m ) , h o l d i n gp o w e r , e l e c t r i c a l p e r f o r m a n c e( w i t h s t a n d v o l t a g e / i n s u l a t i o nresistance/temperature rise limit)and water resistance includingtesting methods.3