plungern.活塞；跳水的人；马桶搋子plunger type lock柱塞型锁plunger joint rod插棒连接杆plunger fuel pump柱塞油泵plunger overtrave柱塞超冲程plunger viscometer活塞黏度计plunger split ring冲头夹环plunger spring cup柱塞弹簧皮碗plunger overtravel柱塞超冲程plunger attenuator活塞式衰减器plunger type brake插棒式电磁铁制动器