Expansion clamp

The utility model provides an expansion clamp. Tapered rod, the conical rod is provided with a conical surface; the device further comprises a moving block and a pressing block. A transverse moving groove is formed in the pressing block; a hole vertically penetrating to the moving groove is formed in the bottom of the pressing block, the inner diameter of the hole is larger than the maximum outerdiameter of the conical rod, the moving block is contained in the moving groove, the moving block is provided with a conical matching face, the conical matching face is close to the middle of the pressing block, and the conical matching face is matched with the conical face. The size of the clamp can be automatically adjusted, the clamp is suitable for parts with different inner hole sizes, the size of the clamp does not need to be manually adjusted, and the adaptability of the clamp to the parts with different sizes is enhanced. 本实用新型提供一种膨胀夹具，包括锥形杆，所述锥形杆设置有锥形面，还包括移动块和压紧块，所述压紧块内设置有横向的移动槽，所述压紧块底部设置有竖直贯穿至移动槽的孔，所述孔的内径大于所