Abstract: Disclosed is a hydraulic pressure booster cylinder. In a low pressure stroke, in a state wherein a slide piston is positioned close to a third piston, as compressed air is supplied into a second pneumatic chamber, a second piston is moved toward a bore, and thereby the third piston and the slide piston are integrally moved to allow a piston rod to extend out of a cylinder case. In a high pressure stroke, when movement of the second piston is blocked by a load, the slide piston is moved toward a check valve and pushes the check valve in one direction, compressed air flows into a first pneumatic chamber and air existing in the second pneumatic chamber is discharged to the outside, and, by movement of a first piston, a trunk piston portion is moved toward the third piston through the bore while maintaining airtightness.

Abstract: Disclosed is a hydraulic pressure booster cylinder. In a low pressure stroke, in a state wherein a slide piston is positioned close to a third piston, as compressed air is supplied into a second pneumatic chamber, a second piston is moved toward a bore, and thereby the third piston and the slide piston are integrally moved to allow a piston rod to extend out of a cylinder case. In a high pressure stroke, when movement of the second piston is blocked by a load, the slide piston is moved toward a check valve and pushes the check valve in one direction, compressed air flows into a first pneumatic chamber and air existing in the second pneumatic chamber is discharged to the outside, and, by movement of a first piston, a trunk piston portion is moved toward the third piston through the bore while maintaining airtightness.