Power Tools

The characters of power tool are light structure, small size, light weight, low vibration, low noise, flexible operation, durable, easy control and operation. Compared with hand tools, power tool can increase the labor productivity several times to several tens of times, also it has low cost and is easy to control which is more efficient than pneumatic tools.

Attention should be paid when purchasing power tools: First, the power tool is a hand-held or removable mechanized tool that is powered by a motor or an electromagnet and drives the working head through a transmission mechanism. Power tools are easy to carry, easy to operate, and versatile, which can greatly reduce labor intensity, improve work efficiency, and realize manual operation mechanization. Therefore, they are widely used in construction, housing decoration, automobiles, machinery, electricity, bridges, gardening and other fields, and enter the family in large numbers. 

So what fields can power tools be used in? There are nine application areas as follow:

1. In the machinery industry: drilling, tapping, sawing, rust removal, polishing, polishing, tube expansion and fastening, etc.
2. Farmland reconstruction, water conservancy construction, tunnel construction, mining: rock and concrete compaction.
3. Railway construction; ballast tamped.
4. In agriculture and animal husbandry: spraying and shearing.
5. Tea picking and forestry: logging, timber, and branching.
6. Wood processing: sawing, planning, tenoning, sanding.
7. Medical treatment: saw bone, drill bone, and remove plaster.
8. In arts and crafts: carving, carpet cutting.
9. Special purpose: cutting steel plates, punching holes, angle drills to drill work pieces in narrow places, magnetic drills can be adsorbed on the processed steel parts, and self-climbing pipe sawing machine can automatically cut large diameter steel pipes. Torque and electric energy control bolts reach constant tension and can riveting work pieces on one side.

What exactly do while selecting a power tool? Here are some tips:

Understand the classification of power tools
Before choosing a power tool, you should first be familiar with its classification. Power tools play different roles in different fields. According to the different fields of operation, power tools can be divided into: assembly power tools, grinding power tools, railway power tools, and metal cutting power tools. Larger power tools include electric hammers, electric screwdrivers, electric drills, electric wrenches, and cutting machines. Moreover, many power tools are becoming more and more functional nowadays, a dual-use or even three-use is normal, and the convenience is greatly increased. You can find various types of power tool on TOOL.com, which has good quality  and wholesale and affordable price for you. 

Observe the quality of power tools
There are some skills to judge whether a power tool is good or bad. Firstly is the appearance quality. Observe whether the appearance is flawed and feel good. Power tools with good appearance and uniform appearance have no obvious defects. Secondly is to check whether the structure of the product is complete. Check the instructions carefully to see if there are defaults. (A lot of small bumps, if you don’t check it carefully, you can’t find it). Thirdly, check whether the material is durable and not easy to be abrasion. Fourthly, it is also very important to check whether its 3C certificate is consistent with the tool’s nameplate parameters, and it is best to check whether the tool’s 3C certificate is currently valid. 

Choosing on a good platform is important
Of course, it’s not that a good brand is decided by good advertising and publicity. The most important thing is to look at the strength of the product. Then how to check the strength of corporate and brand power tools? It is suggested that online platforms are very important. The online platform integrates product display, user evaluation, and instructions for use TOOL.com online store is higly recommended, it has various types of tool for sale. 

How does power tool work?
Motors can be divided into DC and AC motors due to different input currents:

1. DC motor— a motor that uses direct current to run. Due to the different ways of connecting the magnetic field circuit and the armature circuit, it can be divided into universal motor, split-series motor, and double-field motor.
2. AC motor- an induction motor, its strong induced current (eddy current) is generated in the rotating magnetic field, the copper rod on the rotor continuously cuts the lines of magnetic force. According to Lenz's law, this induced current has the effect of opposing the relative movement of the magnetic field and the rotor, so the rotor rotates with the magnetic field. However, the rotating speed of the rotor is not as high as that of the magnetic field transformation, otherwise the magnetic lines of force will not be cut by the copper rod. A motor that uses alternating current to rotate is called an alternating current motor. The mainly types are listed as following:

• A rectifier motor is used as a split-series motor DC generator as an AC motor. This type of motor is formed because the AC is in the magnetic field and the armature circuit, running at the same time, so the direction of the moment of the couple will remain, and the machine rotates continuously. This kind of motor is also called "general motor" because it can use both AC and DC. Vacuum cleaners, sewing machines and other household appliances often use this type of motor.
• Induction motor-a device that puts the rotor in a rotating magnetic field and rotates the rotor due to eddy current. The rotating magnetic field is not created by mechanical methods. Instead, alternating current is passed through several pairs of electromagnets to cyclically change the magnetic pole properties, which can be regarded as a rotating magnetic field. Usually three-phase induction motors (with three pairs of magnetic poles) are used. The movement of a DC motor is exactly the opposite of that of a DC generator. In the generator, the induced current is formed by the induced electromotive force, so they are in the same direction. In the motor, the current is the direction of the induced electromotive force supplied by the external power source and the direction of the armature current I is opposite.
• Synchronous motor-a motor whose armature turns from one pole to the next stage, exactly in the same cycle as the direction of the current. This kind of motor cannot operate independently, and another motor or special auxiliary winding must be used to reach the appropriate frequency before it can be connected to the alternating current. If the load change causes the speed change, then the speed is not in line with the AC frequency, which is enough to make the pace disorder, tend to stop or cause damage. Due to many restrictions, it is not widely used.

Safe use of power tool

• The single-phase power cord of mobile electric machinery and hand-held power tools must use three-core soft rubber cable, and the three-phase power cord must use four-core rubber cable; when wiring, the cable sheath should be inserted into the junction box of the equipment and fixed.
• Check the following items before using power tools:   

1. The shell and handle are free from cracks and damage;
2. The protective grounding wire or the neutral wire is connected correctly and firmly;
3. Cable or cord is intact;
4. The plug is intact;
5. The switch action is normal, flexible and without defects;
6. The electrical protection device is intact;
7. The mechanical protection device is intact;
8. The rotating part is flexible.

• The insulation resistance of power tools should be measured with a 500V megohmmeter on a regular basis. If the insulation resistance between the live parts and the shell does not reach 2MΩ, it must be repaired.
• After the electrical part of the power tool is repaired, insulation resistance measurement and insulation withstand voltage test must be carried out. The test voltage is 380V and the test time is 1 minute.
• Separate switches or sockets should be provided for the electrical circuits connecting electric machinery and tools, and a leakage current action protector should be installed. The metal shell should be grounded; it is strictly forbidden to connect multiple devices with one switch.
• Separate switches or sockets should be provided for the electrical circuits connecting electric machinery and tools, and a leakage current action protector should be installed. The metal shell should be grounded; it is strictly forbidden to connect multiple devices with one switch.
• The rated leakage operating current of the current type leakage protector shall not be more than 30mA, and the action time shall not be longer than 0.1 second; the rated leakage operating voltage of the voltage type leakage protector shall not be more than 36V.
• The operating switch of the power tool should be placed within the reach of the operator. When there is a sudden power failure during break, get off work or during work, the power side switch should be cut off.
• Staff must wear insulating gloves or stand on insulating mats while using portable and mobile power tools; do not carry wires or rotating parts of tools when moving the tool.
• When using Class III insulated power tools on damp or acid-containing sites and in metal containers, reliable insulation measures must be taken and supervised by special personnel. The switch of the power tool should be located within the reach of the guardian.
• The disk plane of the magnetic chuck electric drill should be flat, clean, and rust-free. When performing side or overhead drilling, measures should be taken to prevent the drill body from falling after power failure.
• When using an electric wrench, secure the counter torque fulcrum and make sure that the nut is welly fastened before starting.

Advice of maintaining power tool

1. The oil pump needs to use machine oil No.20.
2. The oil storage capacity must be within the range above the oil window.
3. Every time when refueling and changing oil, it must be filtered with 80 mesh or more oil filter, and the oil tank must be cleaned when changing. The oil change period is six months.
4. Operating oil temperature 10 degrees Celsius to 50 degrees Celsius.
5. Before starting the electric pump, open the bleed nut and place the switch in the unloading position.
6. If the motor temperature is too high during use, then stop using it, and use it after cooling down.
7. The pump has been adjusted before leaving the factory, and it must not be adjusted at will. When re-adjustment is required, a pressure gauge must be used.
8. The high-pressure tubing is imported from the factory and passed the 105MPA test. However, because the hose is prone to aging, users need to check it frequently, usually for six months, and frequent use for three months. During the check, the pressure test is 87.5MPA. If it is damaged, raised, or leaked, it cannot be used.
9. Bearings should generally be cleaned once every six months, and grease must be added during assembly.