The working principle of

Working principle of the electric drill is electromagnetic rotary motor or electromagnetic reciprocating small capacity of motor rotor magnetic field cutting power operation, through the drive mechanism drive operation device, driving gear increase the power of the drill bit, so that the drill bit scraping surface, better into the object.

A brief history of

The birth of the global power tool is from electric drill products - in 1895, the German letter company developed the world's first direct current drill, the drill machine 14 kg weight, shell made from cast iron, can only in 4 mm steel plate with a hole. Then the three-phase power frequency (50 hz) drill, but the motor speed can't exceed 3000 r/min.

In 1914, a single-phase series motor drive electric drill, electric motor speeds above 10000 r/min.

Appeared in 1927, the power supply frequency is 150 ~ 200 hz frequency electric drill, it not only has the advantage of high single-phase series motor rotation speed, but also has the advantages of simple structure, reliable three-phase power frequency motor, but because of the need medium frequency power supply, current use is restricted.

In the '60 s, appeared with nickel cadmium battery power battery electric drill without the power cord. To the mid and late 70 s, due to price battery, charging time is shortened, the electric drill is widely used in Europe and the United States, Japan.

After the electric drill was originally cast iron shell, use aluminum alloy shell. In the '60 s, thermoplastic engineering plastics used in electric drill, and double insulation and implements the electric drill.

Electronic speed drills emerged in the 60 s. This drill using thyristor element composition and so on electronic circuit, switch to press the button is pressed into the depth of the different to adjust speed, so that the electric drill in the use of object can be processed according to the different (such as the material is different, the hole diameter size, etc.), choose a different speed.