Everyone on the CNC machine tools in the "knife" method and operation already "familiar", however, the implication of the "basic principle", but very few people get to the bottom, I combined with their years of operation and maintenance of NC machine tools, the principle and application based on CNC machine tools "knife", and the readers make some discussion.
1. related concepts
Before we elaborate the principles, we first introduce several basic concepts and terminology, all of which are related to the "pair of knives". After knowing these concepts, we will help us further understand the principle of "tool setting".
(1) the reference point of machine tool: a fixed point in machine tool, which is used to set up the datum of machine tool coordinate system. It is determined by machine tool manufacturer. For the machine that uses non memory coder, it usually needs to perform "back reference test point" after starting.
(2) the machine coordinate system determined by the machine tool manufacturers, for the "block" of the "non absolute encoder" machine, usually after back to the "reference point" was established, is to establish their own machine parts. On the basis of the process, the other coordinate system through to the internal logic "the CNC system conversion" into "machine coordinate system", namely the machine coordinate system of CNC system is only able to "identify" the coordinate system.
(3) machine tool origin: zero is the machine coordinate system, then the machine coordinate system to establish zero "(i.e." machine tool origin ") it can be established, and the reference point of the machine (which coincides with the origin of machine tool and machine tool reference point is the same point), also can be inconsistent, is generally by CNC machine tool the system parameters are set up to determine.
(4) workpiece coordinate system is determined by programmers, programming coordinate system, mainly considering programming, machining and clamping. It is the benchmark for programming.
(5): tool reference point: "the knife" operation, usually in the cutting tool point (usually with tool tip) as a benchmark, through the operation and identification of "tool", the CNC system is established between the machine coordinate system and the workpiece coordinate system contact.
The concept and function of 2. "knife to the knife"
The programmer used the workpiece coordinate system, CNC machine tools and can identify the "machine coordinate system", how to make the CNC system can be established by the user "knowing" the workpiece coordinate system in the "where", which requires a "knife", namely "the establishment of the workpiece coordinate system of the origin of the the machine coordinate system in position", after "the knife" after moving track of the knife point should be designated mobile programmers path specified the workpiece coordinate system. Therefore, the "knife" operation is actually the establishment of the link between the coordinate system of the machine tool and the coordinate system of the workpiece, so that they can be converted to each other.
