Several problems that should be paid attention to in the use of grinding machine
grinding machine is one of the most commonly used machine equipment in machinery factories. Whether its installation is reasonable and meets the safety requirements; Whether its use method is correct and whether it conforms to safety operation regulations. These problems are directly related to the personal safety of every employee, so we must pay enough attention to them in actual use
1 precautions in the installation process
1.1 positioning problem where the grinder is installed is the first problem we should consider in the installation process. Only when a reasonable and appropriate position is selected, can we carry out other work. It is forbidden to install the grinding machine in the place directly facing the nearby equipment and operators or where people often pass by. Generally, a special grinding machine room should be set up in the larger workshop. If it is really impossible to set a special grinding machine room due to the terrain of the plant, a protective baffle with a height of not less than 1.8m shall be installed on the front of the grinding machine, and the baffle shall be firm and effective
1.2 balance problem the imbalance of the grinding wheel is mainly caused by the inaccurate manufacturing and installation of the grinding wheel, so that the center of gravity of the grinding wheel does not coincide with the rotation 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, the imbalance accelerates the vibration of the spindle and the wear of the bearing, which will cause the rupture of the grinding wheel and even cause accidents. Therefore, it is required that the sand office building with a straight diameter greater than or equal to 200mm should be statically balanced first after installing the chuck, and the static balance should be repeated after the grinding wheel is reshaped or unbalanced in the work
1.3 matching problem matching problem mainly refers to the installation and matching of chuck and 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 sand office building, and the corresponding provisions require that the grinding wheel should be replaced when the diameter of the grinding wheel is worn to 10mm larger than the chuck diameter. In this way, there is a problem of matching the chuck and the grinding wheel, otherwise, such a situation will occur, "big horse pulling small car" will cause a waste of equipment and materials; "Little horse pulling cart" does not meet the safety requirements, which is easy to cause personal accidents. Therefore, we should cooperate with OEM and its suppliers and processors to develop the most suitable material for each market. The reasonable matching of chuck and grinding wheel can save equipment and materials on the one hand; On the other hand, it meets the requirements of safe operation. In addition, a cushion with a diameter greater than 2mm and a thickness of 1mm~2mm should be added between the grinding wheel and the chuck
1.4 protection problem the protective cover is the main protective device of the grinder. Its function is to effectively cover the grinding wheel fragments and ensure the safety of personnel when the grinding wheel is damaged for some reason in the work. The shape of grinding wheel protective cover can be divided into round and square, 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 protective cover should be installed firmly and reliably, and the protective cover should not be disassembled or discarded at will.
the guard screen is one of the main protective accessories of the grinder, and the opening of the protective cover above the horizontal plane of the main shaft is greater than or equal to 30 ° (this device must be installed when grinding. Its main function is to block the flying in the grinding process, so as to avoid hurting the operator. It is installed at the front end of the opening of the protective cover, and its width should be greater than the width of the protective cover of the grinding wheel, and it should be firmly fixed on the protective cover. In addition, the gap between the circular surface of the grinding wheel and the baffle should be less than 6mm.
1.5 bracket problem bracket is one of the common accessories of the grinder, and the specified diameter of the grinding wheel is more than 150mm The grinder must be equipped with an adjustable bracket. The distance between the grinding wheel and the bracket shall be less than 1/2 of the minimum outline of the workpiece to be ground, but the maximum shall not exceed 3mm
1.6 grounding problem the grinder uses a power line, so the shell of the equipment must have a good grounding protection device. This is also one of the important factors prone to accidents
2 precautions in the use process
2.1 side grinding problem in the daily use of the grinder, we can often find that some operators use the side of the grinding wheel to grind at will, regardless of the type of the grinder and the type of the grinding wheel, which is a serious violation of the safety operation regulations. According to the regulations, the grinding wheel with the circumferential surface as the working surface should not be used for side grinding. The radial strength of this kind of grinding wheel is large, and the axial strength is very small. When the operator forces too much, the grinding wheel will be broken, and even hurt people. This behavior should be prohibited in the actual use process
2.2 problems of front operation in daily use, many operators are used to operating directly against the grinding wheel because they can work hard in this direction. In fact, this behavior should be particularly prohibited in the operation of the grinder. According to the operating procedures, when using the grinder to grind the workpiece, the operator should stand on the side of the grinding wheel and should not operate on the front of the grinding wheel, so as to avoid flying out of the grinding wheel or breaking and flying out of the grinding wheel when the grinding wheel breaks down
2.3 forced operation problem when using the grinder, some operators, especially young operators, exert too much force to make the grinding speed fast, which makes the piston return quickly, which is an extremely unsafe operation behavior. The flattening of any grinding wheel has a certain strength, which is likely to cause the grinding wheel to break, or even fly out to hurt people, which is also a prohibited behavior
2.4 joint operation problems in the actual daily operation, such situations also occur. Some people rush production tasks and work hours, and two people share a grinder to operate at the same time. This is a serious violation of regulations, which should be strictly prohibited. When one grinding machine is not enough, it can be solved by adding grinding machines. It is absolutely not allowed to share one grinding machine at the same time
3 precautions during replacement
3.1 wear problem any grinding wheel has certain wear requirements for use. If the wear condition reaches a certain degree, it must be replaced with a new grinding wheel. In order to save materials, it is not allowed to exceed the wear requirements, which is a very unsafe violation. Generally, when the grinding wheel is worn to a diameter 10mm larger than the chuck diameter, it should be replaced with a new grinding wheel
3.2 validity problem the new grinding wheel received from the warehouse is not necessarily qualified, and even the new grinding wheel purchased from the manufacturer is not necessarily qualified. Any grinding wheel has a certain period of validity. If it is used within the period of validity, 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 "the grinding wheel should be used within the validity period, and the resin and rubber bonded grinding wheel must pass the rotation test after being stored for one year, and the qualified ones can be used"
3.3 texture problem in the process of use, if cracks are found in the grinding wheel, it should be stopped immediately and replaced with a new grinding wheel, so as to avoid crushing and injuring people
4 other precautions
4.1 environmental problems generally, the grinder should be equipped with a special grinding machine room, and it is strictly prohibited to stack inflammable and explosive items in the grinding machine room or near the grinder, so as to avoid fire or explosion accidents, and it is not allowed to put other parts and items around the grinder
4.2 the grinder for management problems should be in the charge of a specially assigned person. When non personnel of the unit want to grind objects on the grinder, they need to obtain the permission of the full-time person in charge, and strictly abide by the safety operation procedures. It is strictly forbidden for outsiders to use the grinder without the consent of the person in charge. In addition, the replacement of the grinding wheel should also be the responsibility of a specially assigned person. It is forbidden for others to replace or install the grinding wheel without permission
4.3 shut down problem the operator should shut down the car immediately after stopping working. It is forbidden to idle the grinder without use or management. In addition, keep the medium and short wave turbine clean after use
the above are some matters that should be paid attention to in the use of grinding machines. I hope it can be helpful for the majority of grinding machines to choose excellent experimental machines from many enterprises. The safe use of grinding machine is an important part of the safety of poor equipment in plastics due to the bending strength and tightening strength of ABS in the factory, which should attract the attention of the majority of installers and users