Tightening machine for engine cylinder

The invention discloses a tightening machine for an engine cylinder. The tightening machine comprises a machine seat and a rack mounted on the machine seat. The tightening machine further comprises atightening device mounted on the rack and a material fixing device located below the tightening device. The material fixing device is used for fixing the engine cylinder. The tightening device comprises a mounting table and further comprises a first tightening shaft, a second tightening shaft and a variable-pitch driving mechanism which are mounted on the mounting table. The tightening end of thefirst tightening shaft and the tightening end of the second tightening shaft both face the material fixing device. The variable-pitch driving mechanism is used for driving the first tightening shaft and the second tightening shaft to move towards each other or move in a mode of deviating from each other in the first direction. According to the tightening machine, bolts of main bearing covers of various types of engine cyli