The birth of world electric tools began with electric drill products - in 1895, Germany developed the world's first DC electric drill, which weighed 14 kilograms and had a casing made of cast iron that could only drill 4mm holes in steel plates. Subsequently, a three-phase power frequency (50Hz) electric drill appeared, but the motor speed did not exceed 3000r/min.

In 1914, a single-phase series motor driven electric drill emerged, with a motor speed of over 10000r/min.

In 1927, an intermediate frequency electric drill with a power supply frequency of 150-200Hz appeared. It not only had the advantages of high speed single-phase series motor, but also had the advantages of simple and reliable structure of three-phase power frequency motor. However, its use was limited due to the need for intermediate frequency current power supply.

In the 1960s, battery drills without power cords using nickel cadmium batteries as power sources emerged. By the mid to late 1970s, due to the decrease in battery prices and shortened charging time, this type of electric drill was widely used in Europe, America, and Japan.

The electric drill initially used cast iron as the casing, but later switched to aluminum alloy as the casing. In the 1960s, thermoplastic engineering plastics were applied to electric drills and achieved dual insulation of electric drills.

In the 1960s, electronic speed controlled electric drills also emerged. This type of electric drill utilizes components such as thyristors to form an electronic circuit, which adjusts the speed of the switch button according to the depth at which it is pressed. This allows the electric drill to choose different speeds based on the different processed objects (such as materials, drilling diameter, etc.) during use.

Principle

The working principle of an electric drill is that the motor rotor of an electromagnetic rotary or electromagnetic reciprocating small capacity electric motor performs magnetic field cutting and power operation. The transmission mechanism drives the operating device, driving the gear to increase the power of the drill bit, so that the drill bit scrapes the surface of the object and better penetrates the object.