Most CNC cylindrical grinders place the parts and the g […]
Most CNC cylindrical grinders place the parts and the grinding wheel on a horizontal line. The high point of the outer circle of the part and the high point of the outer circle of the grinding wheel is called the part/grinding wheel contact point. The diamond dressing tool should be as close as possible to the part/grinding wheel contact point to dress the grinding wheel. For the grinding wheel for internal grinders, it is more important to dress the diamond dressing tool close to the high point of the outer circle of the grinding wheel (that is, the part/grinding wheel contact point when grinding the hole).
1 Take a small amount of trimming
In order to reduce the trimming time, it seems that there is always a temptation to choose a larger trimming depth. This is an extremely wrong idea. You must choose a suitable dressing depth to dress the grinding wheel. Choosing a too large dressing depth will produce high cutting temperature, reduce the service life of the dresser, and also remove the useful grinding wheel layer. The result is damage to both the dresser and the grinding wheel, which is counterproductive. The amount of dressing is based on the criterion that it can not only restore the geometric shape of the grinding wheel, but also produce a good grinding edge after several repairs. Use a single-point dressing tool to contact the diameter direction of the grinding wheel with an inclination angle of the axis line of 10-15o. This will cause the single-point dressing tool to have a sharpening effect when it rotates regularly. Dressing tools with multiple contact points do not need to be tilted at this angle. Instead, use the entire end face of the dressing tool to contact the surface of the grinding wheel.
The lateral movement speed is the speed at which the dressing tool passes through the surface of the grinding wheel during dressing. It plays a key role in the surface roughness and metal removal rate required for machined parts. If the lateral movement speed is too slow, it will block the grinding wheel and damage the surface roughness and metal removal rate of the parts. Too slow lateral movement speed can also cause the grinding wheel to vibrate and burn the surface of the part. The uniform and fast lateral movement speed can dress a good grinding wheel surface, improve the grinding performance of the grinding wheel, increase the grinding efficiency, and reduce the surface roughness of the parts.
2 keep it cool
Appropriate use of coolant can speed up dressing and improve dressing efficiency. Based on experience, choosing a 3/8 inch diameter coolant can remove a lot of heat from the dresser and prolong the service life of the dresser. When the diamond dressing tool passes through the grinding wheel, install a coolant nozzle to cover the entire surface of the grinding wheel or continuously add coolant to the diamond dressing tool. When the dressing tool is in contact with the grinding wheel to start dressing, never agree to the dressing tool and withdraw from the coolant. Otherwise, the diamond dressing tool will crack or break under the change of cold and hot temperature.
The use of a filter to filter the coolant with high precision can avoid multiple cycles of dirt or chips in the coolant. Contaminated coolant can quickly wear the grinding wheel and increase the number of dressings of the grinding wheel. Only in dry grinding (only in this case, the cooling of the diamond dressing tool can be interrupted), the dry dressing of the grinding wheel is adopted. Before leaving work every day, after turning off the coolant, let the grinding wheel run idling for a few minutes. This prevents the grinding wheel from cracking.
3 Vibration is the enemy of dressing (application of form grinding in surface grinding)
In the grinding wheel dressing, it is very important to effectively reduce the vibration and avoid leaving dressing marks, collisions and damage to the dressing tools on the surface of the grinding wheel. This means that the balance of the grinding wheel must also be maintained, which is determined by the structural characteristics of the grinding wheel itself. The uneven density and the geometry of the entire grinding wheel will affect the inherent balance of a grinding wheel. Therefore, choosing a high-quality grinding wheel is also very important. If it is a high-quality grinding wheel, only proper installation can keep the grinding wheel in good balance. According to the factory instructions of the grinding wheel manufacturer, the grinding wheel is marked with an upward arrow, which indicates the light end position of the grinding wheel after rough balance. Then the user can follow the arrow indication and pay attention to dressing the grinding wheel to achieve dynamic balance. The even filling of coolant can sometimes help the grinding wheel to maintain balance.
In order to further avoid vibration, it is necessary to ensure that the dressing tool is firmly clamped on the clamp base and a small amount of overhang is maintained to ensure that the dressing tool has sufficient rigidity. If the diamond tool is not firmly clamped, it will cause vibration, noise, ripple on the surface of the part, strain the surface of the part and damage the dressing tool.