Clamping device for portable boring machine and portable air-drive-drilling machine with clamping device

A clamping device for a portable boring machine, the clamping device being mounted on a front part of a body of the portable boring machine and being for clamping the portable boring machine and a workpiece together, comprising:

• a fixed piston fixed on an outer periphery of the front part of the body;
• a movable cylinder covering the fixed piston, the movable cylinder being movable in an axial direction of a spindle of the portable boring machine;
• a first pressure chamber and a second pressure chamber which are formed in an inside of the movable cylinder and face each other across the fixed piston in a front-rear direction;
• a fluid supply device capable of supplying pressurized fluid into each of the first pressure chamber and the second pressure chamber to move the movable cylinder in the axial direction;
• a connecting mechanism an end portion of which is connected to the movable cylinder;
• and
• a clamping unit connected to the other end portion of the connecting mechanism, the clamping unit being capable of being fixed to a certain position of the workpiece,
• wherein the connecting mechanism connects the movable cylinder and the clamping unit so as to move together with the movable cylinder in the axial direction, and
• wherein the clamping device moves the clamping unit in a direction for clamping and moves the clamping unit in the reverse direction for unclamping through the movable cylinder and the connecting mechanism, using the fluid supply device.