活塞裙部型线
piston skirt profile
Molded line of piston skirt
piston skirt molded lines
活塞裙部型线研究
Study of Piston Skirt Profile
活塞裙部
piston skirt
skirt of piston
Piston skirt cross-section
大中型型钢轧机
heavy and medium section mill
筒状活塞型柴油机
trunk piston type diesel engine