1. Definition of electric wrench
An electric wrench is an assembly tool used to install threaded fasteners and uses a motor as a power source. It is a type of electric tool. There are electric wrenches, electric boards, and electric triggers in China.
2. Classification of electric wrenches
Electric wrenches usually have the following classification methods:
1) According to the classification of motor power: there are two types of plug-in electric wrench and rechargeable electric wrench.
a. Plug-in electric wrench
Plug-in electric wrenches are also called wired electric wrenches, which are provided by public power grids, self-provided generator sets or battery packs, and are divided into low-voltage DC electric wrenches, single-phase electric wrenches, three-phase electric wrenches, and intermediate frequency. Electric wrenches in China generally refer to the two types of electric wrenches that use the most common public grid standard voltage as single-phase 220V electric wrenches and three-phase 380V electric wrenches. Low-voltage DC electric wrenches are generally used in the automotive maintenance industry and are driven by automotive batteries. Electric field wrenches for military field operations and maintenance are also powered by 24V DC.
Intermediate frequency electric wrenches were generally used in pipeline production lines before the 1990s, using 200Hz or higher frequency AC power supply to reduce the weight of the motor by increasing the speed of the motor, which is easy to hold. In recent years, with the development of motor frequency conversion technology and servo technology, intermediate frequency motors have been basically replaced by variable frequency motors and servo motors;
b. Rechargeable electric wrench
Rechargeable electric wrenches are also called wireless electric wrenches, which use battery packs for power supply. According to the type of batteries, they are divided into nickel-cadmium batteries, nickel-metal hydride batteries, and lithium batteries. Currently, nickel-cadmium and nickel-metal hydride batteries are basically eliminated on the market. Batteries are the mainstream, and fuel cells, magnesium-based batteries, and graphene batteries have not been widely used on electric wrenches. According to the assembly form of the battery pack and the tool, it is divided into an integrated charging wrench and a split charging wrench. The integrated battery pack and the tool are called an integrated charging wrench, and the battery pack and the tool are connected through a power cord called a split charging wrench. Generally, the small size or short standby time is required to use the split structure, and the large size or the standby time is strictly required to use the split structure. The split structure is mainly used to consider the weight of the large-capacity battery pack, which does not meet the weight requirements of the handheld tool. With the development of battery technology, integrated design has gradually become the mainstream.
2) According to the angle between the rotor shaft of the motor and the center line of the screw thread fastener, it is divided into: straight direction, angular direction
a. The rotor shaft of the motor and the center line of the screwed screw fasteners on the same axis or parallel line are called straight or straight handle electric wrenches;
b. The angle between the rotor shaft of the motor and the center line of the screw thread fastener is called an angle electric wrench or an angled electric wrench. city
The most common angle on the field is 90°, and 15° and 30°.
3) It can be divided into three types: straight handle, curved angle and gun type according to the hand-held mode.
4) Classification by wrench function and use
This is the current mainstream classification of electric wrenches, which are divided into: impact electric wrenches, fixed torque electric wrenches, fixed-angle electric wrenches, and twist-shear electric wrenches.