1. What principles should the processing sequence be arranged according to?
The arrangement of the processing sequence should be considered according to the structure of the part and the condition of the blank, as well as the needs of positioning and clamping. The important point is that the rigidity of the workpiece is not destroyed. The sequence should generally follow the following principles:
① The processing of the previous process cannot affect the positioning and clamping of the next process, and the general machine tool processing processes should also be considered comprehensively.
②The inner cavity processing procedure is carried out first, and then the contour processing procedure is carried out.
③ It is best to connect the processes with the same positioning, clamping method, or the same tool.
④ For the multiple processes carried out in the same installation, the process with less rigid damage to the workpiece should be arranged first.
2. How to divide processing procedures?
① Tool centralized ordering method: Divide the processes according to the tools used, and use the same tool to process all the parts that can be completed on the part. Use the second knife and the third knife to complete other parts they can complete.
②Sequential method of processing parts: For parts with a lot of processing content, the processing parts can be divided into several parts according to their structural characteristics, such as internal shape, shape, curved surface or plane.
③Sequential method of roughing and finishing: For parts that are prone to processing deformation, due to the deformation that may occur after coughing, correction is required. Therefore, in general, all roughing and finishing processes must be separated.
3. Which aspects should be paid attention to when determining the clamping method of the workpiece?
The following points should be paid attention to when determining the positioning reference and clamping plan:
① Strive to unify the design, technology, and programming calculation benchmarks.
② Minimize the number of clamping and try to achieve all the surfaces to be processed after one positioning.
③Avoid using the manual adjustment scheme of the occupied machine.
④ The fixture should be opened smoothly, and its positioning and clamping mechanism should not affect the cutting during processing (such as collision). In such cases, use a vise or add a base plate to draw a screw.
4. How to determine the tool setting point is more reasonable?
The tool setting point can be set on the part to be machined, but note that the tool setting point must be the reference position or the part that has been finished. When setting the tool in the first process, pay attention to the place that has a relatively fixed size relationship with the positioning reference. Set up a relative tool setting position so that the original tool setting point can be retrieved according to the relative position relationship between them. This relative tool setting position is usually set on the machine table or fixture.
The selection principles are as follows:
① Easy to find.
② Easy to program.
③The tool setting error is small.
④ It is convenient to check during processing.
5. How to choose processing tools reasonably?
When plane milling, you should choose non-reground carbide end mills or end mills. End mills and end mills with carbide inserts are mainly used for processing bosses, grooves, and box mouth surfaces. Ball knives and round knives (also known as round nose knives) are often used to process curved surfaces and variable-bevel contours. The ball knife is mostly used for semi-finishing and finishing. Round knives with carbide tools are mostly used for roughing.
6. What is the function of the processing procedure sheet?
The processing procedure sheet is one of the contents of the CNC machining process design, and it is also a procedure that needs to be observed and executed by the operator. It is a specific description of the processing procedure. The purpose is to let the operator clarify the content of the procedure, the clamping and positioning method, and the location of each processing procedure. The selected tool should be paid attention to.
7. What is the relationship between the workpiece coordinate system and the programming coordinate system?
The origin position of the workpiece coordinate system is set by the operator. It is determined by tool setting after the workpiece is clamped. It reflects the distance position relationship between the workpiece and the machine zero points. Once the workpiece coordinate system is fixed, it is generally not changed. The workpiece coordinate system and the programming coordinate system must be unified, that is, the workpiece coordinate system and the programming coordinate system are consistent during processing.
8. What factors should be considered when determining the knife path?
①Ensure the machining accuracy requirements of the parts.
②Convenient numerical calculation and reduce programming workload.
③ Seek the shortest processing route, reduce the empty tool time to improve processing efficiency.
④ Minimize the number of blocks.
⑤Ensure the roughness requirements of the workpiece contour surface after processing and the final contour should be processed continuously in the last pass.
⑥The path of the tool's advance and retreat (cut-in and cut-out) should also be carefully considered in order to minimize the knife mark left by stopping the tool at the contour.
9. What are the major factors in the cutting amount of the tool?
There are three main elements of cutting parameters: depth of cut, spindle speed, and feed rate. The general principle of the selection of cutting parameters is less cutting and fast feed (that is, the cutting depth is small, and the feed speed is fast).
10. What is DNC communication?
The way of program delivery can be divided into CNC and DNC. CNC means that the program is delivered to the memory of the machine tool through media (such as floppy disk, tape reader, communication line, etc.) for storage, and the program is called from the memory during processing. Processing. Because the capacity of the memory is limited by the size, when the program is large, the DNC method can be used for processing. Since the machine tool directly reads the program from the control computer during DNC processing (that is, it is done while sending), it is not affected by the memory capacity Limited by size.