In the process of multi-species and small batch production, the installation, disassembly and cleaning of the workpiece, automatic exchange of the boss, chip discharge, etc. are frequent throughout the manufacturing process. In order to improve the machining efficiency of CNC machining center, high speed and high performance in machining equipment is one aspect, shortening the installation time and reducing the consumption is another important aspect. Fixture in the manufacturing plant is part of the tooling, it is to ensure accurate positioning of parts, the necessary means of effective processing. For CNC machining center, the requirements of the fixture positioning accuracy is high, easy to install and remove, suitable for rough machining, finishing and various forms of multi-process composite machining.
CNC machining center machining positioning benchmark selection
Before determining the process plan, the reasonable selection of positioning datum has decisive significance to ensure the machining accuracy of
CNC machining center and improve the application efficiency of CNC machining center. In the selection of the positioning datum, the processing situation of each station should be considered comprehensively to achieve the following three purposes.
1. The selected datum should guarantee accurate positioning of workpiece, easy and rapid loading and unloading, reliable clamping, and simple fixture structure.
2. The selected benchmark and the processing part of each size calculation is simple, to ensure the accuracy of the processing, to determine the part fixture.
CNC machining center, the task of the fixture is not only to clamp the workpiece, but also to various directions of the positioning surface as a reference base, to determine the origin of the workpiece programming. CNC machining center of high flexibility requires its fixture than ordinary machine structure more compact, simple, clamping action more quickly and accurately, to minimize the auxiliary time. In the machining machine, in order to reasonably apply good clamping, first of all, we must have a deeper understanding and mastery of the CNC machining center processing characteristics, but also consider the accuracy of the processed parts, batch size, manufacturing cycle time and manufacturing costs.
According to the CNC machining center machine characteristics and processing needs, the types of clamps commonly used are special clamps, combination clamps, adjustable clamps and group clamps. The general selection sequence is to try to use the vise, press the boss screw and other general clamps in the production of a single piece, the batch production priority to consider the combination of clamps, followed by the consideration of adjustable clamps, and finally the choice of special clamps and group clamps. In the selection of a variety of factors to consider, choose the most economical, the most reasonable form of clamps.