The CNC cylindrical grinder is a pre-programmed program according to the processing requirements, and the control system sends out numerical information instructions for processing. It is mainly used for grinding cylindrical and conical outer surfaces.
CNC cylindrical grinders generally have the characteristics of generalization, high degree of modularization, high precision, high rigidity, high efficiency and high adaptability.
According to the different types of CNC operating cylindrical grinders, it is suitable for batch processing of related parts in industries such as automobiles, motorcycles, air compressors, bearings, military, aviation, and aerospace.
The CNC cylindrical grinder is composed of bed, worktable, grinding wheel frame, head frame, tail frame and other parts.
1. Bed and workbench
The bed adopts large round holes and shark fin-shaped ribs. After long-term use, the machine tool has good dynamic and static rigidity.
The working table is divided into upper and lower table, which can grind the conical surface. The guide rails of the bed and worktable adopt plastic-fitted guide rails, which have a small friction coefficient. The worktable is directly driven by the servo motor to move the ball screw, and the movement is stable and reliable.
2. Grinding wheel stand
The linear speed of the grinding wheel is 35m/s or 50m/s or 80m/s, and the grinding efficiency is high. The grinding head is a three-piece dynamic pressure bearing or a dynamic and static pressure bearing, and the rotation accuracy is high. The movement of the wheel carriage (X direction) is directly driven by the servo motor and the ball screw, with a small resolution of 0.0001mm.
The rotation of the headstock dial is driven by the motor’s frequency conversion speed regulation. The dial rotates. The dial’s speed is 40-500r/min infinitely variable sections to adapt to the grinding of different diameters, different materials, and different requirements.
4. CNC box and electric cabinet
There is an independent numerical control operation box with LCD display, machine operation buttons, 1um band compensation switch, hand pulse generator, etc.
5. End face measuring instrument and radial measuring instrument
When the numerical control cylindrical grinder has a radial measuring instrument, the measured value is automatically input into the numerical control system, and the numerical control system sends a signal to make the X-direction servo motor rotate and drive the ball screw to reach the given position, so that the size of the ground workpiece can reach the required stably Position, the size dispersion of the batch grinding workpiece is less than 0.003mm.
The mechanical and electrical integration structure layout adopts work area protection or overall protection, which is convenient for maintenance and meets the requirements of ergonomics.
The grinding wheel spindle system has high rotation accuracy and strong rigidity. The linear speed of the grinding wheel can reach 60m/s; the linear speed of the CBN grinding wheel can reach 80m/s.
Two-axis linkage feed, the worktable and grinding wheel frame are driven by AC servo-ball screw pair.
Various types of diamond dressing devices can be selected to realize precise CNC dressing and automatic die casting compensation.
It is equipped with active measuring device to realize full closed-loop control of grinding processing.
The numerical control system has control functions such as program conversion of the grinding process, workpiece quality management, machine tool status monitoring, fault self-diagnosis and abnormal alarm, and the menu-style interface is easy to input.
Use and adjustment
1. The use and adjustment of the bed
The bed is a casting with a box-shaped structure. The front part of the bed is used as an oil sump, and an independent hydraulic station can also be configured. Equipped with independent electrical cabinets.
2. Use and adjustment of the workbench
The working table is mainly composed of an upper table and a lower table. Loosen the hexagon socket screws of the two pressure plates on the upper table, turn the adjustment handle, and the upper table can rotate within the specified range to adjust the taper of the workpiece. After the upper table is turned to the required angle, the hexagon socket screws of the two pressure plates must be tightened before grinding. The label on the right pressure plate has two scale markings, one for taper and the other for scale. When the upper table rotates more than 6 degrees, the grinding wheel holder must be rotated at a certain angle to avoid collision between the tailstock and the grinding wheel holder.
3. The use and adjustment of the headstock
The head frame is composed of a head frame box and a head frame bottom plate. The head frame box can rotate around an axis on the head frame bottom plate, and the rotation angle can be read from the scale plate.
The headstock dial can realize stepless speed regulation in sections through the pulley and the frequency converter.
The pre-tightening force of the triangle tape at one end of the headstock motor is adjusted by the moving headstock motor. The pre-tightening force of the V-ribbed belt on the headstock dial is adjusted by rotating the eccentric sleeve. When turning the eccentric sleeve, first loosen the set screw, and then tighten the set screw after the eccentric sleeve is turned to the proper position.
The gap between the headstock spindle and the bearing is adjusted by rotating the scale sleeve. The scale sleeve rotates clockwise to increase the gap; otherwise, the gap decreases. When the dead method is used for grinding, the gap can be reduced to zero and the spindle can be locked. When the main shaft needs to rotate, there must be a certain gap between the main shaft and the bearing, generally 0.005mm on the radius is appropriate.
4. Use and adjustment of tailstock
Turn the wrench to make the tailstock sleeve move back.
The foot pedal can make the tailstock sleeve advance and retreat automatically. When the foot is on the bottom, the sleeve moves backward; when the foot is relaxed, the sleeve moves forward.
Turn the adjustment knob to adjust the force of pushing the workpiece. When grinding a slender shaft, the force against the workpiece should not be too large to avoid bending the workpiece.
For grinding external workpieces with low roughness requirements, the diamond pen can be installed on the tailstock for dressing of the grinding wheel.
5. Use and adjustment of the wheel stand
5.1 Overview of the wheel stand
The grinding wheel frame is equipped with a grinding wheel spindle for external grinding, and its bearing is a three-piece dynamic pressure bearing or a dynamic and static pressure bearing. The forward, backward and speed of the grinding wheel frame are controlled by the system and directly driven by the servo motor and the ball screw.
It can be equipped with a rotating or non-rotating wheel stand, and the angle of rotation can be read from the scale plate.
5.2, the installation of the grinding wheel
The grinding wheel is generally installed by a flange. The flange of the flange is composed of the flange base, flange cover, gasket, and hexagon socket screws.
- (1) There should be no obvious defects on the installation base surface of the grinding wheel.
- (2) The axis of the grinding wheel should not be significantly skewed or eccentric relative to the axis of the flange.
- (3) Thick paper should generally be used as a liner when installing the grinding wheel to ensure that the pressure of the grinding wheel during installation and compaction can be evenly distributed on the end surface of the entire grinding wheel.
Precautions for grinding wheel
- (1) When adjusting the balance frame, the adjusting screw should be adjusted slightly, and the rotating action should not be too large.
- (2) After the grinding wheel and the balance spindle are placed on the balance frame, the grinding wheel should be prevented from sliding down from the balance frame and damaging the grinding wheel.
- (3) When rotating the grinding wheel, it should be slightly slow, and the force should not be excessive.
- (4) The balance weight also needs to be moved slightly.
- (5) Always pay attention to that the balance mandrel is perpendicular to the balance cylindrical guide rail.