[Student question] Handheld electric tool operation safety technical briefing?

　　[Answer]

　　1. When using cutting tools, they should be kept sharp, intact, installed correctly, firm and reliable.

　　2. Machines that use grinding wheels generally have a rotational speed of over 10000r/min, therefore, there are strict requirements for the quality and installation of grinding wheels. Before use, the soft pads between the grinding wheel and the connecting plate should be checked and installed firmly. The nuts should not be too tight. Any grinding wheel that is damp, deformed, cracked, broken, chipped, or has come into contact with oil or alkali should not be used, and the damp grinding wheel should not be dried and used on its own.

　　3. Handheld electric tools have high rotational speed and high vibration, and come into direct contact with the human body during operation. Therefore, when working in damp areas or in places with good conductivity such as metal structures, pressure vessels, and pipelines, double insulation or reinforced insulation electric tools must be used.

　　4. Electric motors and appliances with non-metallic casings made of engineering plastics should be stored and used to prevent pressure and moisture, and should not come into contact with solvents such as gasoline.

　　5. The inspection before homework should meet the following requirements: To ensure the normal use of handheld electric tools, they must be inspected according to the following requirements before homework: (1) The shell and handle must not have cracks or damage; (2) The cable and plug are intact and undamaged, the switch operates normally, and the protective neutral connection is correct, firm, and reliable; (3) All protective covers are complete and firm, and the electrical protection devices are reliable.

　　6. After starting the machine, it should run without load. It should be checked and confirmed that the linkage of the equipment is flexible and unobstructed. When doing homework, the force should be applied steadily and not too forcefully.

　　7. Overloading is strictly prohibited. To prevent machine malfunctions and extend the service life, attention should be paid to the sound system and temperature rise during operation. If any abnormalities are found, the machine should be stopped immediately for inspection. When the operation is too long and the temperature rise of the equipment exceeds 60 ℃, the machine should be stopped and allowed to cool naturally before proceeding with the operation.

　　During homework, do not touch cutting tools, molds, and grinding wheels with your hands. If any dullness or damage is found, stop the machine immediately for repair or replacement, and then continue with the work.

　　9. Handheld electric tools rely on the operator's hand for control. If the hand is released during operation, the tool will lose control, which can damage the workpiece, damage the tool, and even cause personal injury. So when the machine rotates, do not let go.

　　When using an impact drill or hammer, the following requirements should be met:

　　(1) When doing homework, one should master the handle of the electric drill or hammer. When drilling holes, first press the drill bit against the working surface, and then start it with moderate force to avoid shaking; If the speed drops sharply, the force should be reduced to prevent motor overload, and it is strictly prohibited to apply pressure with a lever;

　　(2) When drilling, attention should be paid to avoiding the steel bars in the concrete;

　　(3) Electric drills and hammers have a 40% intermittent working system and cannot be used continuously for a long time;

　　(4) When the aperture of the homework is above 25mm, there should be a stable homework platform and guardrails should be installed around it.

　　The above content is compiled based on the problems encountered by students in their actual work, for reference. If there are any problems, please communicate and correct them in a timely manner.