Analysis And Preventive Measures For Ring Grinding Burns (2)

Analysis And Preventive Measures For Ring Grinding Burns (1)
23/04/2024
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In the surface process, such as grinding a surface on a vertical single-head grinder, the following factors may cause burns if the operating specifications are correctly followed. a. The grinding wheel shaft moves, increasing the instantaneous grinding amount and causing burns; at this time, the grinding wheel shaft bearing must be tightened or the bearing must be replaced. b. The disk on the workbench jumps or rotates unevenly, which increases the amount of instantaneous grinding and causes burns; various components of the disk reducer, such as worm gears, worms, etc., must be inspected and worn parts replaced.

① Surface grinding
In the surface process, such as grinding a surface on a vertical single-head grinder, the following factors may cause burns if the operating specifications are correctly followed.
a. The grinding wheel shaft moves, increasing the instantaneous grinding amount and causing burns; at this time, the grinding wheel shaft bearing must be tightened or the bearing must be replaced.
b. The disk on the workbench jumps or rotates unevenly, which increases the amount of instantaneous grinding and causes burns; various components of the disk reducer, such as worm gears, worms, etc., must be inspected and worn parts replaced.
c. The magnetic force of the disk is small or broken, which will cause the workpiece to slip on the disk and cause burns; for maintenance, the charging and demagnetizing circuits should be adjusted.
d. The positioning of the reciprocating stroke is not effective. If the travel switch is not in good contact or the reciprocating reducer components are worn, the worm gear and worm mechanism cannot self-lock, which will cause the carriage to rush, hit, and jump, causing burns. Burns can occur when passing through a double-end surface grinder such as the M7675 series grinder:
●The feeding guide plate is worn, not straight, and the feeding is uneven;
●The guide plate is not parallel to the grinding wheel working surface;
●The inlet of the end face of the grinding wheel is too small, so that the outer edge of the grinding wheel bears most of the cutting amount, and the grinding wheel becomes dull.
②Cylindrical grinding
Centerless cylindrical grinders such as M1083 generally have the following special conditions:
●The feed plate crawls, the knife punches, and the feed amount suddenly increases, causing burns; it is necessary to adjust the wedge iron, clean and lubricate the carriage or scrape the guide plate, repair the screw and nut, and replace worn parts.
●The spark is not adjusted properly. If there is too much grinding at the entrance, the front end will be easily burned. If there is too much grinding at the exit, the workpiece will show spiral marks.
●Excessive cutting amount or poor contact of electrical components will cause the thermal relay to trip in the workpiece, causing the sensitivity to stop. At this time, the tool should be retracted quickly.
③Inner diameter grinding
During the inner diameter grinding process, the contact arc between the grinding wheel and the workpiece is long, which generates more heat; the coolant is not easy to be ejected into the grinding area, and the heat dissipation conditions are poor; wedge removal is difficult and the grinding wheel is easy to plug, all of which lead to high grinding temperatures. The reason is that the coolant must be fully effective and the grinding wheel must be dressed promptly and effectively. Like the MZ208 series internal cylindrical grinder, the compensation mechanism for grinding wheel dressing must be reliable, otherwise burns may occur due to insufficient dressing of the grinding wheel surface. Because the compensation mechanism of this type of machine tool is realized by roller friction transmission, it cannot ensure that the same compensation amount is obtained every time. At present, it is more common to change the compensation mechanism from a roller friction mechanism to a stepper motor mechanism.
④Gutter grinding
For swing-head grinding, the self-sharpening property of the grinding wheel should be strong, and a rubber-bonded grinding wheel is generally used, because at high temperatures in the grinding area, the rubber bond is prone to aging and becoming brittle, and the blunted abrasive grains are easy to fall off under the swing, so , the grinding wheel should always be kept sharp. For plunge grinding, the grinding wheel’s shape-maintaining performance must be strong. Generally, a harder grinding wheel is used, which has poor self-sharpening properties, so it must be trimmed frequently and effectively, and the coolant must be sufficient. For the outer groove process, it is the process most likely to cause burns, and sufficient cooling is particularly important. In addition, due to the different speeds of the grinding wheel surface, the grinding wheel wear is uneven, and the dressing effect is required to be good. The corrector rotation speed must be uniform and stable, and the compensation mechanism must be Reliable, and the diamond should be sharp, and the tip position should be 1 to 2 mm lower than the center of the grinding wheel, otherwise it will easily cause vibration during dressing and affect the dressing effect.