MHYV 1*4*0.5 0.6 0.7 MHYV1*3*0.8矿用通信电缆 MHYV 1*4*0.5 0.6 0.7 MHYV1*3*0.8矿用通信电缆 MKVV|天津市电缆总厂第一分厂