Discussion on the preparation of CNC Lathe processing program
In CNC turning, the program runs through the entire part of the process. Because each person's processing methods are different, the preparation process is also different, but the ultimate goal is to improve the production efficiency of CNC Lathes, so the choice of the most reasonable processing route is particularly important. This article will determine the path from the knife, select the appropriate G command and other details of the starting point in the analysis of NC programming procedures.
First, analyze the part pattern
Analysis of parts design is the primary work in the preparation process, a direct impact on the preparation of parts and processing results. It mainly includes the following contents:
Analyze the geometric conditions of the contours of the contours: The main purpose is to deal with the size of the drawings and the size of the closed chain.
Analyze the dimensional tolerances on the part pattern to determine the machining process that controls the dimensional accuracy of the part, such as the choice of the tool and the determination of the amount of cutting.
Analysis of shape and position tolerance requirements: For CNC Lathe, the shape and position error of the part is mainly affected by the mechanical movement of the machine tool. In the turning, if the direction along the Z axis movement and its axis axis is not flat, you can not guarantee the cylindrical shape of the shape tolerance requirements; and if the direction along the X axis of movement and its spindle axis is not vertical, you can not guarantee vertical This position tolerance requirement. Therefore, before programming to consider the technical treatment of the relevant programs.
Analysis of parts of the surface roughness requirements, CNC Lathe materials and heat treatment requirements, rough requirements, the number of pieces of the requirements of the process and the path of the route and so determine the parameters are not to be ignored.
Second, a reasonable path to determine the knife, and make it the shortest
It is the focus of the machining program to determine the path of the tooling process. Since the finishing process is basically carried out along the contours of the parts, the main content is to determine the route of the roughing and empty stroke. The path refers to the path through which the tool begins to move from the point of the knife until it returns to the point and ends the machining process. Including cutting the path and the introduction of cutting tools, cutting and other non-cutting empty stroke. So that the shortest path can save the entire processing time of the implementation of the time, but also reduce the number of unnecessary tool consumption and machine tool body sliding parts wear. Figure 1 shows the three car cone method, with a rectangular cycle command processing, to analyze the knife route reasonable to determine.
Figure 1a for the parallel car cone method, this method is after each infeed, turning tool movement parallel to the cone bus, with each feed knife, Z phase size increased by a certain percentage, and the general processing cone Body method is the same, so that beginners easy to understand. The Z-size calculation is based on the formula C = D-d / L. If C is 1:10, CNC Lathe the meaning is 1 mm on diameter X and 10 mm on length Z. According to the ratio can be very simple programming, and can guarantee the same amount of each turn to make cutting the same. Figure 1b is to change the cone angle car cone method, with each X-way feed, to maintain the Z dimension to the size of the drawings, each knife has changed the size of the cone angle, only the last knife is the size of the drawings required cone angle. This type of car can not have to carry out each Z-size calculation, but in the processing of the Z-size as the same, so that the processing line is longer, while the cutting allowance is not uniform, affecting the workpiece surface size and roughness, CNC Lathe generally suitable In the conical short, the remaining volume of the cone. Figure 1c for the step processing cone method, this processing method is the path of each knife parallel to the workpiece axis, the processing of many small steps, the last knife knife along the cone slope of the knife, this processing method To do 1: 1 ratio map, or easy to waste the workpiece, because it is stepped, so the balance is not uniform, affecting the quality of cone processing.
Obviously, the three cutting routes, CNC Lathe if the knife point is the same, then the parallel method of the most difficult route, the production of this method for processing.
Third, a reasonable call G command to make the least block
According to each individual geometric elements (ie, straight lines, slashes and arc, etc.) were prepared by the corresponding processing procedures, which constitute the processing procedures of the program block. In the preparation of the processing program, CNC Lathe always want to minimize the number of blocks to achieve the processing of parts to make the program simple, reduce the chance of error and improve the efficiency of programming work.