Grinder safety operating procedures
In the workshop, there are a lot of injuries every year due to grinding wheels bursting or workpieces flying out. For grinder operators, if even one safety rule is missed and not implemented, the price paid is likely to be amputation of fingers or even more serious consequences.
Don’t waste those three minutes changing the grinding wheel.
When it is necessary to replace the grinding wheel, the process must be completed in accordance with the safety operating procedures and one by one to check whether the particle size and linear speed can match.
At the stage before installation, the grinding wheel should be gently tapped. If the sound is crisp, it means that there are no cracks inside the grinding wheel; but if the sound is a dull sound, in this case, it must be scrapped and replaced with a new one. You must not have the wrong idea of just making do with another shift of operation.
In 2024, something like this happened in a certain hardware processing workshop. An operator saved trouble and did not follow the normal process to perform the tapping inspection. Then a newly replaced grinding wheel began to run there at a speed of 3,200 rpm. As a result, it cracked in less than forty minutes. After the fragments flew out, they directly hit the left shoulder of a colleague in the same group. The colleague ended up needing eleven stitches in total. So I had to stop work for two months.
Your standing position and feed determine whether you can stand up to get off work.
The first step before the grinding operation is to tighten the longitudinal stopper to ensure that the reciprocating motion is sensitive. People cannot stand directly in front of the grinding wheel. People must move to the side. This is to prevent the flying debris from being scattered obliquely in the event that the grinding wheel breaks. In this way, the person standing in the front will definitely not be the first person to be hit.
During the feeding operation, the grinding wheel cannot hit the workpiece directly at once. It is necessary to leave a gap of two to three millimeters, and then feed at a slow speed. The sudden force is actually equivalent to providing an impact load to the grinding wheel. Once the limit strength is exceeded, cracks will occur. In this case, there is no second chance.
Don't stretch your hands until the grinding wheel has retreated.
When the grinding wheel has not separated from the workpiece, the spindle cannot stop rotating midway. If you want to load and unload workpieces, or use calipers to measure dimensions, you must first stop the machine and wait until the grinding wheel is returned to a safe position before you can start the operation. If these requirements are violated, the surface of the high-speed rotating grinding wheel will directly wear your fingers.
In 2023, an accident occurred in an auto parts factory . When the operator reached out to touch the surface of the workpiece while the grinding wheel was still cutting, half of his right index finger was worn away. When he was sent to the hospital for treatment, the bleeding had not stopped, and it took more than four months to return to work.
Don’t mix dressing and cooling of the grinding wheel
When using a metal drill to dress the grinding wheel, a fixed bracket must be installed. Holding it by hand is against the regulations. When performing wet grinding machine tool operations, the coolant must be flushed to the required location. When performing dry grinding machine tool operations, the industrial vacuum cleaner must be turned on simultaneously and the dust concentration must be controlled below eight milligrams per cubic meter.
After dressing the grinding wheel and operating the machine before formal use, it must be confirmed that there will be no blockage in the cooling channel. Because once the coolant flow is cut off, the temperature of the grinding area can rise to thousands of degrees in the shortest time, that is, thirty seconds. This will cause the grinding wheel to expand due to heat and directly crack.
Converting dry grinding to wet grinding is a restricted area
In the state of dry grinding, those workpieces are absolutely not allowed to suddenly switch to wet grinding operations, because the drastic change in temperature and the sudden impact of the liquid will cause the tiny cracks on the grinding wheel to expand instantly, and the risk of fragmentation will increase exponentially. The relevant safety regulations have long been clearly written.
Looking from the opposite direction, in the actual operation of wet grinding, once the coolant medium is interrupted, measures must be taken to stop grinding immediately. You must not have any thoughts of being a little more patient and planning to complete the current work. Any extra few seconds of grinding time is directly equivalent to increasing the length of hard friction under no cooling lubrication conditions.
Different grinders have their own pitfalls
When the surface grinder is working, multiple workpieces can be placed at one time, but each workpiece must be close and firmly padded. The gaskets mentioned here are usually made of copper or cork. The purpose of this is to prevent the dangerous situation of tilting and flying out during the grinding process. Before using two ejector pins for processing, the cylindrical grinder must first check whether the cone surface is worn. If a chuck is used for clamping and fixing, Then the workpiece must also be tied tightly.
For the inner hole processed by the internal cylindrical grinder, a plug gauge or a dial indicator needs to be used for measurement. During operation, you should first return the grinding wheel to a safe position, wait for the spindle to completely stop rotating, and then extend your hand for subsequent operations. If you perform measurement work while the spindle is not stopped in order to catch up with the schedule, this behavior is equivalent to gambling on the safety of the speed with your own fingers.
In your workshop, are there any people engaged in grinding operations who stand in front of the grinding wheel? Please tell everyone in the comment area about the most ridiculous operation method you have witnessed and which you think can save time. If you agree that this content has practical value, please click the like button and forward it to your colleagues around you.
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