Positioning and clamping device for circular-hole workpieces

The invention discloses a positioning and clamping device for circular-hole workpieces. The positioning and clamping device comprises a guide base, a supporting base, an inner cavity, a plurality of pressure blocks and a push rod, wherein the supporting base is provided with a cylindrical extending part and inserted into circular holes of workpieces; a periphery extending towards the outer side is arranged on the bottom of the extending part; the periphery is detachably connected with the guide base; the inner cavity is formed inside the supporting base and communicated with a first central through hole; the inner cavity is provided with a plurality of openings in the peripheral surface of the extending part; the pressure blocks are correspondingly arranged in the openings, and an accommodating space with a certain conical degree is formed by the inner walls of the pressure blocks; the push rod is provided with a tapered body, the outer periphery conical degree of the tapered body is matched with the inner wall conical degree of the pressure blocks; a first rod is arranged at one end of the tapered body. The positioning and clamping device has the beneficial effects that quick and reliable clamping and loosening can be realized for the circular-hole workpieces, and accurate positioning can be performed on the circular-hole workpieces.