A circular consolidation abrasive with a central hole made of abrasives and binders, etc. Grinding wheel is one of the grinding tools with the largest consumption and the most widely used surface. It rotates at high speed when used and can be used for rough grinding, semi-fine grinding and fine grinding, grooving and cutting of the outer circle, inner circle, plane and various shapes of metal or non-metal workpiece. There are many kinds of grinding wheels. According to the abrasive used, it can be divided into ordinary abrasive (corundum and silicon carbide, etc.) grinding wheel and super hard abrasive (diamond and cubic boron nitride, etc.) grinding wheel; According to the shape, it can be divided into flat grinding wheel, bevelled grinding wheel, cylindrical grinding wheel, cup grinding wheel, disc grinding wheel, etc. According to the binder can be divided into ceramic grinding wheel, resin grinding wheel, rubber grinding wheel, metal grinding wheel, etc. The characteristic parameters of grinding wheel mainly include abrasive, viscosity, hardness, binder, shape, size, etc. Since the grinding wheel usually works at high speed, rotary test (to ensure that the grinding wheel will not break at the highest working speed) and static balance test (to prevent machine vibration during working) should be carried out before use. After working for a period of time, the grinding wheel should be trimmed to restore grinding performance and correct geometry.
The use of grinding wheel is dangerous. For your safety, here is a list of precautions:
Grinder is one of the most commonly used machines in machinery factory. Whether its installation is reasonable and whether it meets the safety requirements; Whether it is used correctly and conforms to safe operation procedures. These problems are directly related to the personal safety of every worker, so in the actual use must cause us enough attention.
1 Precautions during the installation
Locating the problem where the grinder is installed is the first problem to be considered in the installation process. Only when the reasonable and appropriate location is selected, can we carry out other work. The grinding wheel is not allowed to be installed in a place directly facing nearby equipment and operators or where people often pass by. Generally, a dedicated grinding wheel room should be set up in a large workshop. If it is true that a special grinding wheel room cannot be set up due to the limitations of the plant terrain, a protective baffle plate with a height of no less than 1.8m shall be installed on the front of the grinder, and the baffle plate shall be firm and effective.
The unbalance of grinding wheel is mainly caused by the inaccurate manufacturing and installation of grinding wheel, which makes the center of gravity of grinding wheel not coincide with the rotating shaft. The harm caused by unbalance 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 workpiece surface; On the other hand, the unbalance accelerates the vibration of the spindle and the wear of the bearing, which will cause the fracture 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 static balanced first after the installation of the chuck, and the grinding wheel should be repeated after plastic dressing or when the imbalance is found in the work.
Matching problem The matching problem mainly refers to the matching problem between the chuck and the grinding wheel. According to the standard requirements, the diameter of the grinding wheel chuck should not be less than 1/3 of the diameter of the sand building to be installed, and if the grinding wheel is worn to a diameter 10mm larger than the diameter of the chuck, a new grinding wheel should be replaced. In this way, there is a chuck and grinding wheel matching problem, otherwise there will be such a situation, "big horse car" caused by the waste of equipment and materials; "Small horse and cart" does not meet the safety requirements, easy to cause personal accidents. Therefore, reasonable matching between chuck and 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, between the grinding wheel and the chuck should also be installed with a diameter greater than the chuck diameter of 2mm, thickness of 1mm~2mm cushion.
Protective cover is the most important protective device of grinding wheel. Its function is: when the grinding wheel is damaged for some reason in the work, it can effectively cover the grinding wheel fragments to ensure the safety of personnel. The shape of the grinding wheel shield can be round or square, and the maximum opening Angle is not allowed to exceed 90°. The material of the shield is steel with tensile strength not less than 415N/mm2. When replacing the new grinding wheel, the installation of the protective cover shall be firm and reliable, and the protective cover shall not be disassembled or discarded at will.
The screen is one of the main protective accessories of the grinder, and the opening of the shield above the spindle horizontal plane is greater than or equal to 30(this device must be installed. Its main function is used to shield the grinding process flying silent, so as not to hurt the operator. It shall be installed at the positive end of the opening of the protective cover, the width shall be greater than the width of the grinding wheel protective cover, and shall be firmly fixed on the protective cover. In addition, the clearance between the circumferential surface of the grinding wheel and the baffle plate should be less than 6mm.
Bracket problem Bracket is one of the commonly used accessories for grinder. Adjustable bracket must be set for grinder whose diameter of grinding wheel is more than 150mm according to regulations. The distance between the grinding wheel and the bracket shall be less than 1/2 of the minimum contour inch of the grinding part, but the maximum shall not exceed 3mm.
Ground problem The grinder uses power lines, so the enclosure of the equipment must have good ground protection. This is also easy to cause one of the important factors of accidents.
2 Precautions during use
In the daily use of grinder, we often find that some operators, regardless of the type of grinder, regardless of the type of grinding wheel, arbitrarily use the side of the grinding wheel for grinding, which is a serious violation of the safety operation rules illegal operation behavior. According to the rules, the grinding wheel with the circumferential surface as the working surface should not use the side side for grinding. The radial strength of this grinding wheel is large, but the axial strength is small. Too much force from the operator will cause the grinding wheel to break and even hurt people.
In daily use, many operators are always used to operating on the grinding wheel, the reason is that this direction can be used to force, in fact, this behavior is the grinder operation should be particularly prohibited behavior. According to the operating rules, 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 the grinding wheel flying out or grinding wheel breaking out when the fault occurs.
In the use of grinding turbine, some operators, especially young operators, in order to grinding speed, too much force, which is a very unsafe operation behavior. The flat body of any grinding wheel has a certain strength, so it is likely to cause the grinding wheel to break, or even fly out to hurt people, which is also a behavior that should be prohibited.
Common operation problem In the actual daily operation, there are such cases, some people in order to catch the production task, grab the working time, two people share a grinder operation at the same time, this is a serious illegal operation behavior, should be strictly prohibited. When a grinder is not enough, it can be solved by adding a grinder. It is absolutely not allowed to share a grinder at the same time.
3 Precautions during the replacement
Wear problem Any grinding wheel has its certain wear requirements, wear situation reached a certain degree must be replaced with a new grinding wheel. Not in order to save materials, on the use of super wear requirements, this 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.
The new grinding wheel taken from the warehouse may not be qualified, even the new grinding wheel bought from the manufacturer may not be qualified. Any grinding wheel has its certain validity period. If used within the validity period, it is qualified grinding wheel. Beyond the expiry date of use, it is not necessarily qualified grinding wheel. According to the regulations, "the grinding wheel should be used within the effective period, and the resin and rubber bonded grinding wheel must pass the rotary test after storage for one year, and the qualified person can use it".
In the process of use, if cracks are found locally in the grinding wheel, the grinding wheel should be stopped immediately and replaced with a new one, so as to avoid the grinding wheel crushing and wounding accident.
4. Other matters needing attention
Environmental problems Generally, a special grinding wheel room should be set up for the grinding wheel room and flammable and explosive materials should not be piled near the grinding wheel room or the grinding wheel to avoid fire or explosion accidents, and other parts and articles should not be placed in the vicinity of the grinding wheel.
There should be a special person in charge of the grinder. Anyone who does not want to grind on the grinder shall obtain the permission of the full-time person in charge and strictly abide by the safety operation rules. It is strictly prohibited to use the grinder without the consent of the person in charge. In addition, the replacement of the grinding wheel should also be responsible for the special person, and it is forbidden to replace or install the grinding wheel without permission.
When the operator stops working, the vehicle should be shut down immediately. It is prohibited to idle the grinder when no one is in use or under management. In addition, the medium and short wave turbine should be kept clean after use.
