LJ4B4-20-J/FM,LJ4B4-20-J/CM,3SG3275-IKJ86,LJG3D-20,HY-2020,电感式接近开关 LJ4B4-20-J/FM,LJ4B4-20-J/CM,3SG3275-IKJ86,LJG3D-20 无锡市昌林自动化科技有限公司