CHUCK DEVICE BY FLUID PRESSURE

摘要

PURPOSE:To enable a device to high accurately and stably hold a material to be clamped so that its axial line may be almost aligned to the axial line of a holding part, by giving the pressure of fluid to a pressed surface of the holding part so as to perform holding of the material to be clamped and its release from the holding. CONSTITUTION:A cylindrical sleeve 6 has in its part in the direction of an axial line an elastically deformable cylindrical holding part 11 in the diametrical direction, and the holding part 11 respectively constitutes its one surface to a holding surface and the other surface 4to a pressed surface. Here the cylindrical holding part 11 is formed in a double-layer shape by the first layer part 13 situated in a holding surface side of the holding part 11 and the second layer part 14 situates in a pressed surface side of the holding part 11. While the first layer part 13 forms a thin thickness elastically deformable in the diametrical direction, and the second layer part 14 forms a large thickness in the diametrical direction integrally with the first layer part 13 almost in the central part in the direction of the axial line of the holding part 11. Here a chuck device is constituted so as to tighten the peripheral surface of a material 10 to be clamped by the internal peripheral surface of the holding part 11 if the pressure of fluid in an annular space 21 increases.