With the improvement of operation accuracy, the requirement of torque wrench is higher and higher in all walks of life, so what should be paid attention to in the selection of torque wrench?

　　电动力矩扳手是一种可以随电源进行扭矩设定的高精度扳手。它是一种拧紧和拆卸螺栓的工具

　　The electric torque wrench is a kind of high precision wrench which can set the torque with the power supply. It is a tool for tightening and removing bolts

　　扭转剪切型是专门用于扭转剪切型螺栓的扭转。电动扳手按螺栓标准选用。高精度扭矩主要用于有扭矩要求的场合，根据扭矩大小选用电动扳手;冲击式电动扳手便宜、效率高，但扭矩精度差，是螺栓标准的电动扳手。

　　Torsion shear type is specially used for torsion of torsion shear type bolts. The electric wrench shall be selected according to the bolt standard. High precision torque is mainly used for occasions with torque requirements, and electric wrench is selected according to the torque size; impact electric wrench is cheap and efficient, but the torque accuracy is poor, which is the preferred electric wrench for bolt standard.

　　，看它的准确性

　　First, look at its accuracy

　　达到预定扭矩后，高精度扳手停止准确转动。特别是法兰螺栓的上紧精度高，建议使用高精度扳手，有效防止泄漏。德国电动扳手的一般精度为正负3%，是目前世界上精度的扳手。

　　After reaching the preset torque, the high-precision wrench stops rotating accurately. In particular, the tightening accuracy of flange bolts is high. It is recommended to use a high-precision wrench to effectively prevent leakage. The general accuracy of the German electric wrench is plus or minus 3%, which is the highest in the world.

　　第二，看看扭矩

　　Second, look at the torque

　　一般情况下，国产力矩扳手的扭矩可达10000牛顿，而德国电动扳手的扭矩可达40000牛顿。根据螺栓尺寸和工艺要求，选择合适的扭矩尺寸。

　　In general, the maximum torque of domestic torque wrench can reach 10000 newtons, while that of German electric wrench can reach 40000 Newtons. According to the bolt size and process requirements, select the appropriate torque size.

　　三，看速度

　　3、 Look at speed

　　旋转速度直接决定了操作效率，扳手的快速旋转速度，可以为操作者节省宝贵的操作时间。

　　The rotation speed directly determines the operation efficiency. The rapid rotation speed of the wrench can save the operator precious operation time.

　　四，看马达

　　4、 Look at the motor

　　现在有两种类型的电机:有刷电机和无刷电机。

　　Now there are two types of motor: brush motor and non brush motor.

　　什么是碳刷?

　　What is a carbon brush?

　　换向器的顶部内部有一个电刷电机外形，电机转动时，电能通过换向器传到线圈上，因为其主要成分是碳，称为碳刷，所以很容易磨损。应定期保护置换，并清理积存的碳。

　　There is a brush motor shape inside the top of the commutator. When the motor rotates, the electric energy is transmitted to the coil through the commutator. Because its main component is carbon, which is called carbon brush, it is easy to wear. The replacement should be regularly protected and the accumulated carbon removed.

　　无刷电机工作原理?

　　How does BLDCM work?

　　无刷电机采用电子换相，线圈不动，磁极转动。无刷电机,是一套电子设备的使用,通过霍尔元件,对永磁磁极的位置,根据这一观念,电子电路的使用,切换时线圈中的电流方向,确保磁力的正确方向,驱动马达。电刷电机的缺陷。

　　The electric commutation is adopted for the BLDCM, the coil does not move, and the magnetic pole rotates. BLDCM is the use of a set of electronic equipment. Through Hall element, the position of permanent magnet pole is determined. According to this concept, the use of electronic circuit, the direction of current in the coil when switching, to ensure the correct direction of magnetic force and drive the motor. Eliminate the defect of brush motor.

　　无刷电机虽然有点贵，但因为故障率很低，寿命长，性价比相对较高。

　　Although the BLDCM is a bit expensive, it has low failure rate, long service life and relatively high cost performance.