Working principle

The working principle of electric motor rotor electromagnetic rotary or reciprocating electromagnetic small capacity motor to do work cutting magnetic field operation, operation device driven by the transmission mechanism drives the gear increase bit power, so the drill bit scraping the surface of the object, through the object better.

Brief history

The birth of the world electric tool was started from the electric products -- in 1895, the German Fein company developed a DC electric drill, drill the weight of 14 kilograms, the shell is made of cast iron, the drill hole of 4 mm in the plate only. Then there was a three-phase power frequency (50Hz) electric drill, but the motor speed failed to break through the 3000r/min.

In 1914, an electric drill driven by a single phase series motor was introduced, and the motor speed was over 10000r/min.

In 1927, the power supply frequency is 150 ~ 200Hz frequency electric drill, it not only has the advantages of high speed single-phase series motor, and has the advantages of simple structure, reliable three-phase motor, but because the need if current supply is limited.

In 60s, there was a battery powered drill without a power cord using a nickel cadmium battery. By the middle and late 70s, the batteries were widely used in Europe, America and Japan because of the reduction of battery price and the shortening of charging time.

The electric drill is made of cast iron and the outer shell is made of aluminum alloy. In 60s, thermoplastic engineering plastics were applied to electric drills, and double insulation of electric drills was realized.

In 60s, an electric speed drill was also introduced. This drill thyristor components of electronic circuits used to regulate the speed of different switch to snap is pressed into the depth, thereby the drill can be processed according to the different objects (such as in the use of different materials, hole diameter), the choice of different speed.