Electric drills can be divided into three categories: hand electric drills, percussion drills and hammer drills.
1. Electric drill: Minimum power, limited to the use of wood drilling and when an electric cone, some electric drills can be changed into special tools according to their use, with more uses and models.
2. Percussion drill: There are two kinds of percussion mechanism of percussion electric drill: canine tooth type and ball type. Ball impact drill consists of moving disc, fixed disc, steel ball, etc. The movable disc is connected with the spindle by threads and has 12 steel balls. The fixed disc is fixed on the casing by pins and has 4 steel balls. Under the action of thrust, 12 steel balls roll along 4 steel balls, which makes the cemented carbide bit produce rotary impact motion and can drill holes on brittle materials such as bricks, blocks and concrete. Remove the overhead nail, so that the fixed plate rotates together with the driving disc, without impact, and can be used as a common electric drill.
3. Hammer drilling (electric hammer): It can drill holes on a variety of hard materials and has the widest application range.
These three kinds of electric drills are arranged from low to high, and their functions are also increased. The selection needs to be combined with their respective application scope and requirements.
The difference between hand drill, percussion drill, hammer drill and pick.
The hand electric drill only relies on the motor to drive the transmission gear to increase the force of the bit rotation, so that the bit can be scraped through metal, wood and other materials.
There are adjustable knobs, adjustable drills and percussive drills at the bit chuck when the percussive drill works. But the impact drill uses the gear on the inner shaft to beat each other to achieve the impact effect, and the impact force is far less than the electric hammer. It can also drill reinforced concrete, but the effect is not good.