Engaged in mechanical processing industry, CNC processing equipment is essential, commonly called machining center, also known as computer gong. Whether a machining center can meet the accuracy requirements of processing products, the first is that the accuracy of the machining center itself is higher than that of the product, and the accuracy of the machining center affects the processing quality. If you judge whether the precision of a machining center meets the requirements of processing products, the accuracy of the machining center can meet the requirements The product requirements are evaluated in the following four aspects:
1. Placement of workpiece in vertical machining center:
The workpiece should be placed in the middle position of x stroke, along the Y and Z axis, at the appropriate position suitable for the positioning of workpiece and fixture and tool length. If the workpiece is abnormal and the rotation area is unconventional, it can be solved through communication with the equipment manufacturer.
2. Workpiece fixation:
After the workpiece is fixed with special fixture, the maximum stability of the tool and fixture should be achieved. Ensure that the fixture and workpiece mounting surface should be straight.
After checking the parallelism between the mounting surface of the workpiece and the clamping surface of the fixture, it is necessary to fix the workpiece with the countersunk screw to avoid interference between the tool and the fixture. A more suitable method can be selected according to the structure of the workpiece.
3. Material, tool and cutting parameters of workpiece:
The material, cutting tool and cutting parameters of the workpiece shall be selected according to the agreement between the manufacturer and the user, and shall be recorded. The recommended cutting parameters are as follows:
1) Cutting speed: About 50M / min for cast iron and 300m / min for aluminum
2) Feed rate: about (0.05 ~ 0.10) mm / tooth.
3) Cutting depth: the radial cutting depth of all milling processes should be 0.2mm
4. Workpiece size:
After the workpiece is processed, the size changes and the inner hole increases. During the inspection and acceptance process, it is recommended to select the final contour machined part size for inspection, so that if this reflects the accuracy change of the equipment, the test workpiece can be processed repeatedly and tested many times. Before each test, a thin-layer cutting should be carried out to clean the previous surface and facilitate identification.
In the process of using the machining center, why is the precision getting worse and worse? The reason is that after the machine tool is running, the transmission chain in front of each axis of the machining center has changed, such as the wear of the production lead screw, the gap, the change of the pitch error, etc. the compensation amount can be adjusted again to solve these abnormal problems. The length of machine stop and the preheating of machine tool will also affect the accuracy of machining center. In order to ensure the accuracy of machine tool, the machine should keep continuous normal operation when processing some products with high precision.
Post time: Oct-12-2020