亚洲阿v天堂2019国产_真实播放国产乱子伦视频_白丝美女被爆操视频在线观看_国产综合色在线视频观看_久久99精品一久久久久久_99久久久久无码国产精品性_亚洲无码线上试看_国产日韩欧美一区二区三区麻豆_亚洲色总一区二区_亚洲国产精品点击进入_91久久偷窥撒尿一区二区_97在线精品一区_国产精品久久久无码_狠狠久久综合色惰_97无码人妻免费视频碰碰碰

1. The purpose of the equipment is the workpiece condition.

2. Structural characteristics, load conditions, required speed, size stroke and action requirements of the working mechanism.

3. The selected hydraulic system working pressure.

4. Current status of materials, accessories and processing technology.

5. Relevant national standards and technical specifications.

6. The piston rod should be subjected to a large load in the multi-tension state as much as possible, and has good longitudinal stability under multi-pressure conditions.