根据我国铁路目前的情况,迫切需要一种具有较大扭矩且能自动控制扭矩的电动扳手应用于机车的制造和修理生产线上,以减轻工人的劳动强度,提高技术精度,满足机车的运用要求。为此,我们研制了SDB-300型双速定扭矩电动扳手。整机方框图见图1,电气原理如图2所示。 According to the current situation of China’s railway, an electric wrench with high torque and automatic torque control is urgently needed to be applied to the manufacturing and repairing production lines of locomotives in order to reduce the labor intensity of workers, improve technical accuracy and meet the requirements of locomotive operation. To this end, we have developed SDB-300-type two-speed constant torque electric wrench. The whole block diagram shown in Figure 1, the electrical principle shown in Figure 2.