The grinding wheel machine is one of the most commonly used machines and equipment in the machinery factory. Whether its installation is reasonable and meets safety requirements; whether its use method is correct and meets safety operating procedures. These issues are directly related to the personal safety of every employee, so we must pay enough attention to them in actual use.
1 Precautions during installation
Positioning problem Where the grinding wheel machine is installed is the first issue we need to consider during the installation process. Only when a reasonable and appropriate position is selected can we carry out other work. The grinding wheel machine is prohibited from being installed facing the nearby equipment and operators or where people often pass by. Generally, a dedicated grinding wheel machine room should be set up in a larger workshop. If a dedicated grinding wheel machine room cannot be set up due to the limitations of the factory terrain, a protective baffle with a height of not less than 1.8m should be installed on the front of the grinding wheel machine, and the baffle must be firm and effective.
Balance problem The imbalance of the grinding wheel is mainly caused by the inaccurate manufacture and installation of the grinding wheel, which causes the center of gravity of the grinding wheel to not coincide with the rotating axis. The harm caused by imbalance is mainly manifested in two aspects. On the one hand, when the grinding wheel rotates at high speed, it causes vibration, which is easy to cause polygonal vibration marks on the surface of the workpiece; on the other hand, imbalance accelerates the vibration of the spindle and the wear of the bearings. In severe cases, it will cause the grinding wheel to break and even cause accidents. Therefore, it is required that the grinding wheel with a diameter greater than or equal to 200mm should be statically balanced after being installed on the chuck. The grinding wheel should be statically balanced again after being shaped and trimmed or when imbalance is found during work.
Matching problem The matching problem mainly refers to the installation and matching of the chuck and the grinding wheel. According to the standard requirements, the diameter of the grinding wheel chuck shall not be less than 1/3 of the diameter of the installed grinding wheel, and the corresponding regulations stipulate that the grinding wheel should be replaced with a new grinding wheel when it is worn to a diameter 10mm larger than the chuck diameter. In this way, there is a matching problem between the chuck and the grinding wheel. Otherwise, such a situation will occur, "a big horse pulling a small cart" causes waste of equipment and materials; "a small horse pulling a big cart" does not meet safety requirements and is prone to personal accidents. Therefore, the reasonable matching of the chuck and the grinding wheel can save equipment and cut materials on the one hand; on the other hand, it meets the requirements of safe operation. In addition, a soft pad with a diameter greater than the chuck diameter by 2mm and a thickness of 1mm~2mm should be installed between the grinding wheel and the chuck.
Protection issues The protective cover is the most important protective device of the grinding wheel machine. Its function is: when the grinding wheel is damaged for some reason during work, it can effectively cover the grinding wheel fragments to ensure the safety of personnel. The shape of the grinding wheel protective cover is round and square, and the maximum opening angle is not allowed to exceed 90°; the material of the protective cover is steel with a tensile strength of not less than 415N/mm2. When replacing a new grinding wheel, the installation of the protective cover must be firm and reliable, and the protective cover must not be disassembled or discarded at will.
The shield is one of the main protective accessories of the grinding machine. This device must be installed when the opening of the shield is greater than or equal to 30 (above the horizontal plane of the spindle. Its main function is to block the flying noise during the grinding process to avoid injuring the operator. It is installed at the front end of the shield opening, the width should be greater than the width of the grinding wheel shield, and it should be firmly fixed on the shield. In addition, the gap between the circumferential surface of the grinding wheel and the shield should be less than 6mm.
Bracket problem The bracket is one of the commonly used accessories of the grinding wheel machine. According to regulations, the grinding wheel machine with a grinding wheel diameter of more than 150mm must be equipped with an adjustable bracket. The distance between the grinding wheel and the bracket should be less than 1/2 of the minimum outer dimension of the workpiece being grounded, but the maximum should not exceed 3mm.
Grounding problem The grinding wheel machine uses a power line, so the housing of the equipment must have a good grounding protection device. This is also one of the important factors that easily cause accidents.
2 Precautions during use
Side grinding problem In the daily use of grinding machines, we often find that some operators use the side of the grinding wheel for grinding at will, regardless of the type of grinding machine or the type of grinding wheel. This is an illegal operation behavior that seriously violates the safety operating procedures. According to the regulations, the grinding wheel with a circular surface as the working surface should not be ground from the side. This type of grinding wheel has a large radial strength and a small axial strength. If the operator uses too much force, it will cause the grinding wheel to break or even injure people. This behavior should be prohibited in actual use.
Frontal operation problem In daily use, many operators are always accustomed to operating the grinding wheel directly, because they can use force in this direction. In fact, this behavior is a behavior that should be particularly prohibited in the operation of the grinding machine. According to the operating procedures, when using a grinding machine to grind workpieces, the operator should stand on the side of the grinding wheel and must not operate from the front of the grinding wheel to prevent the grinding wheel from flying out or breaking and flying out to injure people when the grinding wheel fails.
Force operation problem When using a grinding machine, some operators, especially young operators, use too much force to achieve a faster grinding speed, which is an extremely unsafe operation behavior. Any grinding wheel has a certain strength. Doing so is likely to cause the grinding wheel to break or even fly out and injure people, which is also a prohibited behavior.
Joint operation problem In actual daily operations, there are also such situations. In order to catch up with production tasks and work time, two people share a grinding machine and operate it at the same time. This is a serious violation of regulations and should be strictly prohibited. When a grinding machine is not enough, you can use the method of adding a grinding machine to solve it. It is absolutely not allowed to share a grinding machine at the same time.
3 Precautions during replacement
Wear problem Any grinding wheel has its certain use and wear requirements. When the wear reaches a certain level, it must be replaced with a new grinding wheel. It cannot be used beyond the wear requirements in order to save materials. This is an extremely unsafe violation of regulations. Generally speaking, when the grinding wheel is worn to a diameter that is 10mm larger than the chuck diameter, a new grinding wheel should be replaced.
Validity period problem New grinding wheels taken out of the warehouse are not necessarily qualified grinding wheels, and even new grinding wheels purchased from manufacturers are not necessarily qualified grinding wheels. Any grinding wheel has a certain validity period. If it is used within the validity period, it is a qualified grinding wheel; if it is used beyond the validity period, it is not necessarily a qualified grinding wheel. The regulations stipulate that "grinding wheels should be used within the validity period. Resin and rubber bonded grinding wheels must be subjected to a rotation test after one year of storage, and qualified ones can be used."
Texture problem During use, if cracks are found in part of the grinding wheel, it should be stopped immediately and replaced with a new grinding wheel to avoid accidents caused by the grinding wheel breaking and injuring people.
4 Other matters to be noted
Environmental issues Generally, a special grinding wheel room should be set up for the grinding wheel machine, and it is strictly forbidden to stack flammable and explosive items in the grinding wheel room or near the grinding wheel machine to avoid fire or explosion accidents. Other parts and items should not be placed randomly near the grinding wheel machine.
Management issues The grinding machine should be managed by a dedicated person. If non-unit personnel want to grind objects on the grinding machine, they must obtain permission from the full-time person in charge and strictly abide by the safety operating procedures. It is strictly forbidden for outsiders to use the grinding machine without the consent of the responsible person. In addition, the replacement of the grinding wheel should also be the responsibility of a dedicated person, and others are prohibited from replacing or installing the grinding wheel privately.
Shutdown issues The operator should shut down the machine immediately after stopping work. It is forbidden to idle the grinding machine when no one is using it or managing it. In addition, the medium and short wave machine should be kept clean after use.
The above are a few things that should be paid attention to during the use of the grinding machine. I hope it can be helpful to the majority of users of the grinding machine. The safe use of the grinding machine is an important part of factory equipment safety and should attract the attention of the majority of installers and users.