CNC machining services process planning refers to the whole process, which can’t be judged by the nature of a process and the processing of a face. For illustration, some positioning detail, in thesemi-finishing stage or indeed in the rough processing stage will need to be reused veritably directly. Occasionally in order to avoid dimensional chain conversion, in the finishing stage, also can arrange some secondary face semi-finishing.
After determining the processing system and processing stage of the part face, the processing of each face in the same processing stage can be combined into several ways.
The system of processing procedures division The corridor reused on CNC machine tools are generally divided into the following styles according to the principle of process attention Divided by the tool used
Taking the process completed by the same tool as a processing procedure, this division system is suitable for situations where there are numerous workpiece shells to be machined. Machining centers frequently use this system to complete. Divided by the number of workpiece installations
The technological process that can be completed by the corridor in one setting is regarded as a process. This system is suitable for corridors with many processing contents. Under the premise of icing the processing quality of the corridor, all processing contents can be completed in one sitting. Divided by roughing and finishing
The part of the process completed in rough machining is regarded as one process, and the part of process completed in finishing is regarded as another process.This division system is suitable for corridors that have strength and hardness conditions, bear heat treatment or bear high delicacy of the corridor, need to effectively remove internal stress, and have large distortion after machining, which needs to be divided into rough and finish machining stages.
Divided by recycling part
The part of the process that completes the same profile as a process. For the corridor with more complicated processing face, the sequence of CNC processing, heat treatment and supplementary working procedure should be nicely arranged, and the connection problem between working procedures should be answered. Principle of process
Corridor are made up of multiple shells that have their own perfection conditions and also have corresponding perfection conditions between the shells.
In order to achieve the design perfection of corridor, the arrangement of machining sequence should follow certain principles. Roughing first, finishing latterly.
The processing sequence of each face is carried out in the order of roughing,semi-finishing, finishing and finishing, with the purpose of gradationally perfecting the delicacy and face quality of the reused face of thepart. However, the process arrangement is generally carried out in the order of roughing,semi-finishing, If all shells of the part are reused by CNC machinetools.
During rough machining, utmost of the machining allowance can be snappily removed, and also each face can be finished in sequence, which can ameliorate product effectiveness and insure the machining delicacy and face roughness of the corridor.
This system is suitable for crafted shells that bear high positionaccuracy.This isn’t absolute, similar as for some advanced dimensional delicacy conditions of the machining face, taking into account the stiffness of corridor, distortion and dimensional delicacy conditions, can also consider these machining face independently according to rough machining,semi-finishing, finishing process order tocomplete.
For machining shells with high perfection conditions, it’s stylish to leave the corridor for a period of time between roughing and finishing processes, so that the face stress of the corridor after roughing can be fully released, and the degree of stress and distortion on the face of the corridor can be reduced, which is salutary to ameliorate the machining delicacy of the corridor.
1) Datum face first processing principle At the morning of processing, the face used as the finishing reference is always reused. Because the face of the positioning reference is accurate, the setting error is small. Thus, in the processing of any part, the positioning reference face is always roughed and semi-finished. Machining, finishing if necessary, for illustration, shaft corridor always rough andsemi-finish the positioning reference face before finishing. For illustration, for shaft corridor,
the center hole is always reused first, and also the hole system and other shells are reused on the center hole face and the positioning hole as a perfection referenced. However, the processing of the reference face should be arranged in agreement with the sequence of reference conversion and the principle of gradationally perfecting the processing delicacy, If there’s further than one perfection reference face.
2) Face process first, hole process latterly. For box, type, machine body and other corridor, the aeroplane figure size is larger, and the aeroplane positioning is more stable and dependable, so the aeroplane face should be reused first, and also the hole should be processed.In this way, not only the posterior processing has a stable and dependable aeroplane as the positioning reference face, but also the processing of holes on a flat face makes the processing easier, and it’s also conducive to perfecting the processing delicacy of theholes.
3) Generally, the processes can be divided according to the processing positions of the corridor, and the simple geometric shapes are reused first, and also the complex geometric shapes are reused; the lower perfection corridor are reused first, and the advanced perfection corridor are reused first; the airplane is reused first, and the hole is reused latterly.
4) Inner hole first, external circle latterly. For perfection sleeves, the coaxiality between the external circle and the hole is needed. Generally, the principle of the first hole and external circle is espoused, that is, the external circle is used as the positioning reference to machine the hole, and also the hole with advanced perfection is used as the positioning reference to reuse the external circle. Round, which can insure a high coaxiality demand between the external circle and the hole, and the institution structure used is also veritably simple.
5) Reduce the number of tool changes principle In CNC machining services, the machining sequence should be arranged as far as possible according to the order in which the tool enters the machining position.