1) High rigidity and high stability bed The bed adopts […]
1) High rigidity and high stability bed
The bed adopts the overall granite structure. Due to the characteristics of high damping, small vibration and good thermal stability, granite can guarantee high rigidity and high stability of the grinding machine.
The working table adopts the overall granite structure. Based on the traditional closed static pressure guide rail, a high-rigidity, high-precision large-plane closed static pressure guide rail is developed to realize the large stroke, stable and reliable reciprocating movement of the table. The table is driven by SIEMENS linear motors. At the same time, in order to prevent the motion of the linear motor from affecting the table surface, an independent static pressure guide rail is specially designed for the linear motor. The motion state of the tabletop is controlled by the closed loop of the HEIDENHAIN encoder system, thereby ensuring that the table has the motion characteristics of high precision and fast response.
3) Posts, slides and beams
It can control the deformation of the machine due to heat. The columns and beams are made of granite. The horizontal displacement slide of the grinding wheel is placed on a fixed beam, and the vertical moving carriage on which the wheel frame is installed is placed on the horizontal displacement slide. Lateral displacement and vertical movement are completed by SIEMENS servo motor directly driving high-precision ball screws, and HEIDENHAIN encoder position feedback. The lateral displacement slide and the guide rail of the vertical moving carriage also use the hydrostatic guide rail. In addition, the vertical movement carriage is equipped with a micro-feed mechanism, which can realize the micro-feed of the wheel carrier 0.1 μm. In order to reduce the deformation of the beam caused by the weight of the wheel carriage slide and its lateral displacement, an unloading device (unloading beam) is set directly above the beam. It is used to bear most of the weight of the wheel carriage slide, and the movement of the unloading device and the wheel's lateral displacement slide carriage is synchronized through the position feedback of the HEIDENHAIN grating, thereby minimizing the impact of the beam deformation on the grinding process.
4) Grinding wheel frame
A wide-speed, high-rigidity, high-precision grinding wheel static spindle system was developed to achieve high rigidity and high-precision rotary motion of the grinding wheel. Grinding wheel shaft is supported by hydrostatic bearing, SIEMENS built-in spindle motor, cooling fluid is used to force cooling the spindle motor, the grinding wheel spindle is equipped with grinding wheel balancing device, and the supporting management control program can continuously monitor the condition of the grinding wheel in the cycle and immediately detect the situation of the grinding wheel. The unbalance amount is compensated.
5) Measurement system
The machine tool is equipped with a laser interferometer as an in-situ measurement system for processing accuracy. Through the movement of the machine table and the measurement of the lateral movement of the carriage, the lens of the laser interferometer can scan all processing areas. When the machine tool is grinding, the measuring beam can move beyond the machining range.
The ultra-precision large-size optical glass surface grinder is researched and developed in response to the major needs of the country's important optical engineering industry. It is a key equipment of ultra-precision machining with international advanced level. The successful development of this project can achieve high-precision and high-efficiency grinding of 450 × 1200mm optical glass, and the flatness of the workpiece can reach 3μm, which greatly shortens the subsequent grinding and polishing time, and can meet the ultra-precision of laser weapons, aerospace and other fields. The large-scale demand for large-size flat glass is of great significance to the development of astronomy science, national key projects and military equipment in China, and will further promote technological breakthroughs in manufacturing equipment in the optical and laser fields in China, and enhance the core competitiveness and Creativity.