Principle and Related Maintenance of Centerless Grinder Grinding
The function of a centerless grinder is to perform high-precision and relatively small rough surface grinding Hub holder for high-speed rotating hubs in feed motion.
The workpiece is sucked away or clamped on a rectangular electromagnetic workbench, and reciprocates longitudinally. The grinding wheel holder can intermittently feed horizontally along the dovetail guide rail of the slider, and the slider base can intermittently feed vertically along the column guide rail. Movement, grinding the workpiece around the grinding wheel, with high grinding accuracy. Vertical axis table grinding machine: Vertically arranged grinding wheel spindles grind the workpiece using the grinding wheel end face. The grinding wheel frame can intermittently feed material vertically along the column guide rail, and install the workpiece. Continuous grinding can be carried out on a rotary table, and a centerless grinder has high production efficiency. To facilitate the loading and unloading of workpieces, the round table can also be moved longitudinally along the bed frame guide rail.
Centerless grinding machines are mainly used for grinding the two parallel surfaces of the inner and outer rings of small and medium-sized bearings, as well as for grinding the two parallel surfaces of circular and nearly circular workpieces such as piston rings, valve seats, valve plates, and connecting rods. The machine adopts a through-feed method, with the feed speed adjusted by an AC frequency converter, and the feed speed is infinitely variable. The structure of the machine tool is horizontal., High repetitive positioning accuracy, long service life, and convenient maintenance.
1. The main shaft oil pressure is limited to 8-10KG/CM;
2. Use a lubricator to properly lubricate the machine tool before starting it every day;
3. Add an appropriate amount of lubricating oil to the sliding plate every day to keep it clean (clean, free of debris and impurities, and in a lubricated state);
Always check the tightness of the zipper;
5. Regularly check the tightness of the grinding wheel drive belt;
The spindle of the machine tool should be replaced every 2000 hours of use.
Centerless grinding machines are a type of grinding machines that do not require the use of the axis of the workpiece for grinding. "It is composed of three mechanisms: a grinding wheel, an adjustment wheel, and a workpiece holder. The grinding wheel actually performs the grinding task. The adjustment wheel controls the rotation of the workpiece and causes the workpiece to have a feed speed. As for the workpiece holder, which supports the workpiece during grinding, there can be several ways to cooperate with these three mechanisms, except for stopping grinding, which is the same in principle.". Centerless grinding machines can automatically trim and compensate. The guide wheel feed guide rail is a dual V-shaped needle roller guide wheel fed by a servo motor that can compensate for grinding wheel dressing. The machine tool is equipped with an automatic loading and unloading mechanism, which can perform automatic circular grinding. The development of centerless grinding machines has gone through the process of completely relying on system suppliers to initially having general development capabilities. However, the application of CNC systems is still in the stage of improving the performance of mechanical transmission chains, replacing mechanical handwheels, and simple processing cycles. Compared with advanced levels, centerless grinding machines still have many gaps, and there is a lot to improve in terms of machine tool accuracy, automation functions, processing efficiency, and reliability of centerless grinding machines Breakthrough issues need to be resolved. Summarize the various structures and use processes of various products currently produced, analyze their advantages and disadvantages, explore what automatic functions the product should achieve, and have a plan for its gradual development to facilitate learning and work; Attaching importance to the development of CNC software, centerless grinders have the conditions to introduce technology or learn from overseas, to keep up with the development trend. In terms of hardware, combined with market needs, centerless grinders will apply new technologies and new functions one by one in product manufacturing, in order to narrow the gap with advanced levels. In the centerless grinding machine industry, to promote industrial progress. The formulation of new standards and the revision of old standards lag far behind the development of the industry. Due to changes in government agencies, industry standards have not been addressed. Given the very backward standards, it seems impractical for mindless grinders to propose creating international brands. To create an international brand of centerless grinding machines, domestic standardization work must take the lead. To further establish contacts with international standardization organizations and establish cooperative relationships based on communication, thereby improving the international competitiveness of China's product standards, creating an international brand has the foundation.
The general operating method is to come back three laps during the feed and then enter three laps to remove errors caused by gaps. If it is still inaccurate, we need to perform other operations. Have a brief understanding of how to handle this matter. 1. Check to see if the screw brake handwheel is locked. If you are not sure about it, the two pins of the brake handwheel tap against the screw rod have fallen off. Grasp the screw brake handwheel tap and check for reinstallation. If the feed of the lower slider is not accurate, check whether the left or right side of the object rack has touched the falling workpiece. This problem sometimes occurs and needs to be checked. 2. For centerless grinding machine types, because the tool is fed from the lower right corner, check whether the set screw of the feed handwheel and the anti retraction screw on the feed screw are loose or the gap is too large. Rolling back and forth feels like the gap between the handwheels is too large, or if the handwheel is too tight when rotating. 3. Slightly adjusting the offset or looseness of the feed housing downward will cause the sliding conflict to cause excessive clearance between the helical gear and the adjustment screw. Or tightening the nut will make the rotation inflexible. Generally, loose nuts can also lead to inaccurate feed. 4. Both the handwheel fine adjustment and the screw rod differential disc drive screws have fixed screws, and it is also necessary to ensure that there are no looseness, fine adjustment screws, and the edge bearing of the screws to ensure that there is no wear or excessive clearance. For slightly worn parts, they can be properly tightened, and severely worn parts need to be replaced in a timely manner. Matching high-quality parts as much as possible can improve the feed accuracy of the grinding machine and reduce the maintenance rate of the machine.
A grinding machine that uses a centerless grinding method to grind the rotating surface of a workpiece is commonly referred to as a centerless cylindrical grinding machine. On a centerless cylindrical grinding machine, the workpiece is not centered and supported by the center, but is placed between the grinding wheel and the guide wheel and supported by the tray and guide wheel. The grinding wheel is generally installed at the end of the spindle, and the grinding wheel with a width greater than 250mm is installed in the middle of the spindle. The width of the grinding wheel can reach 900mm. The grinding wheel rotates at a high speed for grinding, and the guide wheel rotates at a slower speed in the same direction, thereby driving the workpiece to rotate for circular feed. During grinding, axial feed is achieved by adjusting the slight inclination of the guide wheel shaft, which is suitable for grinding elongated cylindrical workpiece, short shaft without central hole, and sleeve type workpiece. In the process of plunge grinding, radial feed is achieved through the movement of a guide wheel frame or grinding wheel frame. It is suitable for grinding workpieces with shoulders or bosses, as well as cones, spheres, or other workpieces with curved curves. Centerless grinding machines have high productivity and are easy to automate with the addition of various handling devices. Most of them are used for mass production and can be operated by unskilled workers. The grinding accuracy of centerless grinding machines is generally 2 microns for roundness and 4 microns for dimensional accuracy. High precision centerless grinding machines can reach 0.5 microns and 2 microns respectively. In addition, there are centerless internal grinding machines and centerless thread grinding machines. Centerless grinder can automatically trim and compensate. The guide wheel feed guide rail is a dual V-shaped needle roller guide wheel supplied by a servo motor and can be mutually compensated by grinding wheel trimming. The machine tool is equipped with an automatic loading and unloading mechanism for automatic circular grinding.