The precision of grinding wheels on double disc grinding machines directly determines workpiece machining quality. Over time, grinding wheels may experience wear, dullness, or surface irregularities, necessitating scientific dressing to restore their cutting performance. Grinding wheel dressing is a critical process for ensuring machining accuracy, requiring strict adherence to standardized procedures while balancing safety and precision.
Thorough preparation is essential before dressing. First, shut down the machine and disconnect the power supply. After the grinding wheel has completely stopped, clean the wheel surface and the machine tool worktable of metal chips and grinding wheel dust to prevent contaminants from affecting dressing results. Simultaneously inspect the grinding wheel's condition to assess wear levels and identify defects such as chipped edges. Select the appropriate dressing tool based on the situation—common options include diamond dressing sticks and diamond dressing wheels. Diamond dressing wheels are ideal for efficient dressing in mass production, while diamond dressing sticks are better suited for small-batch processing or fine adjustments.
Dressing operations must be executed according to standardized steps. Start the machine tool under no-load conditions. Once the equipment reaches stable rotational speed, slowly advance the dressing tool, ensuring perpendicular contact with the grinding wheel surface to prevent uneven dressing caused by tilting. Dressing depth must be reasonably controlled; a single pass should not exceed 0.01-0.03mm. Employ multiple back-and-forth passes to progressively remove the passivation layer and uneven areas from the grinding wheel surface. Continuously monitor the grinding wheel's condition during the process. Assess contact quality by listening for abnormal sounds and observing spark patterns. Immediately stop the machine for inspection and adjustment if unusual vibrations or uneven sparking occur.
Post-dressing precision verification is essential. Utilize tools such as dial indicators and flatness gauges to measure the parallelism and flatness of both grinding wheel faces, ensuring deviations remain within process specifications (typically parallelism error ≤0.005mm). Concurrently perform test machining to verify the dressing effectiveness by inspecting workpiece dimensional accuracy and surface roughness. If requirements are not met, perform secondary dressing until machining standards are satisfied.
Furthermore, safety protocols must be strictly observed during dressing. Operators should wear protective eyewear, gloves, and other safety gear to prevent injury from flying grinding wheel debris. Dressing tools require regular inspection and maintenance to ensure diamond tips remain sharp, thereby enhancing dressing efficiency and quality. Proper grinding wheel dressing not only extends the wheel's service life but also ensures stable workpiece machining, making it an indispensable core process in the operation of double disc grinding machines.