The Basic Structure of the Electric Drill (Part 2)

 Electric drill tools are composed of shell, drive mechanism, work head, handle, power switch, and power connection components. China tools supplier to share with you:

The electric motor and driving mechanism are directly connected with the working head, and the electric tool is directly connected with the soft shaft.

1. Motor

There are mainly single-phase series motor, three-phase, single-phase power frequency, and three-phase intermediate frequency (150 ~ 400HZ) asynchronous cage motor and permanent magnet dc motor. The single-phase series wound motor is the most used motor in the electric tools because of its high torque, small volume, large starting torque, and the capability of both ac and dc.

The three-phase power frequency cage asynchronous motor has the advantages of simple structure, convenient manufacture and maintenance, constant speed, reliable operation, and durability. It is mostly used for high-power power tools and movable power tools. The three-phase intermediate frequency cage asynchronous motor has both the advantages of three-phase power frequency cage asynchronous motor and the advantages of high speed and a small volume of single-phase series excited motor, but it needs to be equipped with intermediate frequency power supply, so its development and application are limited to some extent.

2. Shell

The outer shell plays the role of support and protection. It has the characteristics of high strength, lightweight, heat resistance, harmonious color, and beautiful shape.

Generally made of engineering plastics or aluminum alloy. The engineering plastic material is reinforced nylon or polycarbonate. The application of engineering plastics not only reduces the weight of power tools but also improves the safety of power tools.

3. Transmission mechanism

The transmission mechanism is mainly used to transfer energy, decelerate and change the direction of movement.

In order to meet the needs of various processing operations, the working model of the working head of electric tools includes rotation, reciprocation, impact, and vibration, as well as a combination of impact and rotation.

The transmission gear is the most widely used transmission form in electric tools, including spur gears, helical gears, spur and spiral bevel gears, internal gears, harmonic gears, etc. The characteristics of the transmission are: high speed and large speed ratio, and the modulus are mostly between 0.6 and 1.5 mm. The strength of the gear must not only meet the requirements of long-term full-load operation and overload but also ensure that it can withstand braking torque and impact force several times greater than full load.

4. Working head

The working head of the electric tool is a tool, cutting tool, grinding tool, and other working tools that perform various processing on the workpiece and its clamping part. Cutting tools and cutting tools are various drills, taps, drills, saw blades, etc .; abrasive tools are grinding wheels, abrasive cloths, grinding heads of various shapes and sizes; polishing tools are various polishing wheels; nut sleeves, screwdrivers (Screwdriver), tube expander, etc.

5. Handle

According to the different requirements and structure of the handle, there are double horizontal handles, rear handle, pistol handle, straight rear handle, etc. Some small and micro tools, such as electric punching shears, electric shears, and mini screwdrivers, do not have special handles and can be operated directly by holding the casing. Some tools also have auxiliary handles on the front to reduce the labor intensity of the operator.

There are two types of connection between the auxiliary handle and the power tool housing: thread connection type and clamp clamping type.

The screw connection type is to directly connect the handle to the power tool shell through the connection thread on the handle. The clamp clamping type coupling is made into a clamp shape at the coupling end of the handle, and the coupling of the neck of the electric tool is clamped by the clamp.

6. Power switch and interference suppression components

The structure of the switch for electric tools mostly adopts a two-pole bridge-type double-break contact and has an instantaneous action mechanism to make the contact quickly turn on and off. The hand-push switch can automatically reset and cut off the power supply, and some are also equipped with a self-locking mechanism. The speed control switch generally uses a combination of thyristor and electronic circuit to achieve the functions of speed regulation, speed control, and opening and closing of the circuit. When working, the positive and reverse electric tools need to use specially designed positive and reverse switches.

Electric Drill Tools

Most of the switches of China power tools are installed in the handle, which requires small size, compact structure, safety, and reliability, and cannot be replaced by ordinary switches. The device for suppressing radio disturbance is installed in the handle or housing. Combined capacitors and inductive chokes are used to suppress single-phase series excitation or AC and DC power tools from harassing TVs and radios.

7. Power connection assembly

The power connection assembly is composed of a power plug, a flexible cable or cord, and a power cord sheath, etc. It is used to connect the power tool to the power grid. Most flexible cables or cords use light rubber sheathed flexible cables or plastic sheathed cables.

Flexible cables or cords should be firmly clamped and sheathed at the entrance of the power tool. The sheath is made of insulating materials such as rubber and thermoplastic.

Power tools must use a reinforced insulated power plug, and it is a non-reconnectable power plug that is molded with a power cable and a flexible cable or cord.