大连机车车辆工厂机械一车间的工人师付发扬敢想、敢干精神试制了缸头螺栓液压拉伸器,用以使缸头螺栓拉伸到一个预定的长度,然后把紧螺母,释放拉力,从而使缸头螺栓获得一个规定的预应力,以保证缸头和机体之间,具有可靠的紧固状态。如果此预应力过小,则柴油机在运转时,缸头和机体之间不能保证足够的紧密,如果此预 Dalian locomotive and rolling stock factory workers in a workshop to pay to advance, dare to try a trial of the hydraulic cylinder head bolt, for the cylinder head bolt to a predetermined length, and then the tight nut, release the tension, So that the cylinder head bolt to obtain a pre-stress, to ensure that the cylinder head and the body, with a reliable fastening state. If the prestress is too small, then when the diesel engine is running, the cylinder head and the body can not be guaranteed enough tight, if this pre