Sheathing top edge folding rivetter

The utility model discloses a sheath upper opening rivet turning machine which overcomes the shortages that hammers and copper bars are used for knocking the edges of sheath upper openings for turning rivets on cylinder covers with uneven riveting and low yield, can not prevent liquid and gas leakage and knock cylinder covers forming damage caused by bad control. The utility model comprises a cylinder on the upper part of the utility model and a reverse cone which is connected with the lower part of the utility model and can be partially arranged in sheath upper openings. Because the rivet turning on sheath upper openings is caused by the downward pressing, the supporting and the expanding of the reverse cone, the utility model has uniform riveting and high yield and can prevent liquid and gas leakage; because the rivet turning machine is placed little higher than cylinder covers, the utility model doesn't knock and damage cylinder covers when the utility model knocks. The utility model has the advantages of simple structure, low cost and high rivet turning efficiency, and one reverse cone of the utility model can be suitable for the requirements of a plurality of sheath upper openings with different sizes.