MULTIPLE TYPE SEALING DEVICE

PURPOSE:To enable simultaneous and uniform pressurization by only an electric signal, by a method wherein a turning motion of an electric motor driven by the electric signal through a controller is converted into reciprocal movement by a transmission device, a piston within a cylinder of a liquid pressure generating device is positioned, fixed liquid pressure is generated and fed to each plunger of a plunger mechanism for a plurality of sealing presses through a branched oil path. CONSTITUTION:An electric signal is sent to an electric motor 32 through a controller 30 so that a liquid pressure value becomes an established value based on the liquid pressure value detected by a pressure sensor 54 and the electric motor 32 is turned by a fixed number of revolutions at a fixed speed. With this turning, a screw bar 48 is moved in the direction X while turning by this turning, a piston 50 of a liquid pressure generating device 36 which is in an integrated state is positioned within a cylinder 52 and the liquid pressure corresponding to this position is generated within the branched oil path 38. Decompression is applied uniformly to the under surfaces 22A-22C and pressure-controlled wholly by the same pressing force, the liquid pressure with the branched oil path 38 is detected by a pressure sensor 54 and feedback- controlled by the controller 30.