1. Product process preparation process

1.1 Basic tasks of process preparation

The effective formulation of the process preparation work plan mainly includes the following aspects. First of all, the determination of the content of the process preparation, as well as the formulation of the workload and cycle. Secondly, determine the detailed division of labor between the production department and the process department. Thirdly, to ensure that the processing of the product conforms to the technical basis specified in the product design, so that the scrap rate and repair rate can be reduced. 1.2. Work procedures for process preparation

If the work procedure of process preparation is divided according to time sequence, work nature and work content, it can usually be divided into the following three stages. First of all, the first stage is a reasonable review of the product structure processability and process investigation. Secondly, the process design includes three small aspects, namely, the proposal of process equipment task book, process equipment design, and the overall compilation of process documents. The last link specifically includes product trial production and appraisal, process rectification, process product summary, ordering and verification. 2. Analysis of the machining process of truck axles

First of all, in the process of processing the axles of the trucks, the blank axles are first processed automatically, and the process of positioning into holes is completed here. Then the diameter and overall length of the fixed axle body are determined, and there is no need to make major adjustments when processing later. Secondly, when the rough axle is automatically controlled and processed, several important processes such as assembly, fine turning, journal, grinding, and rolling should be done, so as to promote the axle to meet the design needs as a whole. Finally, according to the accuracy of the processing, implement the work of sub-machine flow, and take the fine turning operation to the CNC machine. It must be noted that there is a margin for subsequent processing. 2.1. Determine the clamping plan. Before the axles are processed, the axles are positioned according to the basic needs of the truck axles, the processing technology and parameters are set, and the bracket clamps are used in the CNC machine tools. After installing the clamps on the axles, use the well-positioned port and take this port as the standard position, so that the back end and the front end of the CNC machine tool are both the same live center. However, because of the lack of a bracket clamp in the middle of the machine tool, if you want to complete the turning process, you must do it separately, first turning one end, and then turning the other end. In the process of turning, pay attention to the gap between the front of the axle and the front of the shift fork to prevent the center hole from becoming deeper, resulting in lower machining accuracy.

2.2, clear the feed line

During the machining of the axle, the feed line should also be clarified, and it is also the main part of controlling the movement trajectory of the axle in the machining. First of all, the core of the feed line programming is to ensure the entry and exit points of the machine tool from the beginning to the processing of the parts. Secondly, if the feed route is set reasonably, the occurrence of empty tools can be reduced to a large extent, and the use efficiency of the machine tool can be improved in an all-round way. Finally, to complete the rough turning, simply to locate the center hole position and end face of the axle, so the whole process of implementing the axle mechanical fine machining process, the starting place should be the two ends of the axle, and then the center position of the axle is processed. 2.3, determine the coordinate system of the system

The determination of the axle coordinate system is usually to determine the machining origin at the position of the axle before turning the axle. As for the establishment of the coordinate system of the axle, the programming should be simplified, and the size conversion should be simple, thereby effectively reducing the occurrence of errors. In specific applications, in order to improve the machining accuracy of the axle and facilitate the preparation of the degree of machining, the origin is usually set at the intersection of the front end of the axle and the axis. This can ensure the unity of the three aspects, such as the unity of the reference, the unity of the assembly and the Unity of design. 2.4, select props

After the axle machining process is completed, it is necessary to fully consider the issue of tool selection. From the point of contact of the tool, it is not so easy to process, because it is not an ideal point, but an arc shape, so when chamfering, arc cutting and bevel processing, processing is likely to occur Unsatisfactory, excessive processing. For this reason, when processing, the tool should be used to do appropriate processing compensation work to make up for some deficiencies. 2.5, select cutting amount

When processing, you should also do a good job of selecting the amount of turning. The purpose of this work is to set the parameters such as feed, depth and speed during cutting. The setting of precise parameters has a positive effect on the improvement of the overall work quality. First of all, according to the design standards and the requirements in the process manual, make a reasonable choice in the amount of cutting, and then go to match the processing of the axle. Secondly, in order to reach Ra1.7 in the standard, the turning depth must be fixed, controlled in the range of 0.5 to 0.7mm, and then the feed rate is set, the value is from 0.2 to 0.3mm/r. 3. The preparation of the process card of the bushing parts. The preparation of the process is a detailed process, which can well represent the pattern, technical requirements, precision requirements, and surface finish of the parts, and then use the optimization of cutting parameters, equipment The selection and final programming are completed. When programming, not only automatic programming can be used in the completion method, but manual programming can also be used. Each finishing method must reflect the accuracy of part size and part shape. The first is manual programming. According to different shapes and stations, choose a more suitable processing method, and then use different programming instructions to compile according to the plan. Secondly, when automatic programming, modeling is the first priority, using CAXA software to select different processing modes and operating methods, in order to complete the simulation and subsequent processing work. The last step is to transfer the program to the CNC machine tool. After the program is called, the entire operation process is completed.