Lithium electric wrench

A fixed torque electric wrench is an electric wrench that can automatically control torque. It is suitable for bridge structures, large steel towers, steel structure factories, metallurgical equipment frames, large crane frames, mine steel frames and other engineering projects that require high-strength bolt connections, as well as large diesel engines, power generation equipment, chemical equipment. Bolts that require constant clamping force connections can also be tightened with torque wrenches.

Especially in modern bridge construction, fixed torque electric wrenches are an effective tool to replace "riveted welded beams" with "bolted welded beams". This is of great significance for simplifying the installation process on construction sites, reducing bridge construction costs, alleviating labor intensity, and accelerating bridge construction.

Electric wrench is a handheld electric tool used for loading and unloading threaded connectors. It is widely used in the assembly work of manufacturing industries such as automobiles, tractors, motors and electrical appliances, power machinery, valves, water pumps, textile machinery, etc. In chemical, cement prefabricated parts, plastic molding and other operations, it is used for the assembly and disassembly of vacuum tanks, reaction vessels, cement templates, and demolding of threaded plastic parts in the production process; It can also be used in railway, bridge, construction and other engineering projects for the installation, maintenance and replacement of cement sleepers, truss nodes, angle steel scaffolding and other structures.

When the end face of the nut comes into contact with the end face of the workpiece, the resistance torque sharply increases. The rotating spiral groove causes the ball to move backwards with the active impact block, overcoming the frictional force and the pressure of the working spring, causing the teeth of the active impact block and the driven impact block to disengage from each other. At this point, the passive impact block does not move, while the active impact block continues to move backwards. After turning the teeth of the driven impact block, the active impact block instantaneously moves forward due to the action of the working spring, and generates an angular acceleration along the spiral groove. The active impact block collides with the driven impact block, causing the two teeth to collide. Then the spiral groove causes the ball and the active impact block to move backwards and disengage. This creates repeated collisions, obtaining the required impact torque to tighten the nut.

If the power switch is connected to the reverse position, the nut can be unscrewed. The double insulated single-phase series excited electric wrench is equipped with two switches on the operating handle. One is a work switch that controls the start and stop; The other is specifically designed to change the forward and reverse rotation of the armature, and the two switches cannot be reversed.

Electric wrenches have two structural types: safety clutch type and impact type.

The safety clutch type is a structural type that uses a safety clutch mechanism that disengages when a certain torque is reached to complete the installation and removal of threaded components; The impact type is a structural form that uses an impact mechanism to complete the installation and removal of threaded parts with its impact torque. The former, due to its simple structure, small output torque, and certain reactive torque, is generally only suitable for manufacturing electric wrenches of M8mm and below; The latter has a more complex structure and high manufacturing process requirements, but its output torque is large and the reaction torque is very small, which is generally suitable for manufacturing larger specifications of electric wrenches.

The impact electric wrench consists of an electric motor, planetary gear reducer, ball screw groove impact mechanism, forward and reverse power switches, power connection devices, and a motorized socket.

The impact electric wrench can be divided into single-phase series excited electric wrench and three-phase electric wrench according to the type of electric motor selected.

The motor device of the single-phase series excited electric wrench is located inside a plastic casing. The plastic casing is used as both a structural component to support the motor and an additional insulation for the motor stator. Due to the significant axial tension between the end face of the plastic housing of the electric motor and the plastic front cover of the planetary gear reducer and ball screw groove impact mechanism during the assembly or disassembly of threaded parts in the impact electric wrench, as well as the high assembly accuracy required for the planetary gear reducer, metal inserts are installed at the stopper, bearing chamber, and threaded connection of the plastic housing to enhance the rigidity of the housing, improve the processing accuracy of the plastic housing, and enhance the ability of the connection to withstand axial forces.