Anyang Xingyang Machine Tool Co., Ltd. (Anyang Xingpu Machine Tool Co., Ltd.
Zhao Guangqing: 137-0372-2538
High valley: 135-233-30323
Wang Ming: 139-37236227
Address: Dongfeng Industrial Agglomeration Zone, Long'an District, Anyang City, Henan Province
Our company mainly produces CW6163C series, standard 80 series, CW61100C series machine tools and CK6163C series CK6180 series CK61100C series CNC machine tools. At the same time according to user requirements to produce various mechanical products, production and sales of various product spare parts and assembly components.
How can CNC machining improve workpiece machining accuracy and machining efficiency?
Under the condition that the rigidity permits, the rough cutting takes a larger cutting depth to reduce the number of passes and improve the productivity of the workpiece; the finishing processing generally takes a smaller cutting depth to obtain a higher surface quality. Affects the final machining accuracy and efficiency of the workpiece. In addition to the reasons of the CNC machine tool itself, it should also be based on reasonable machining route settings, tool selection and correct installation, reasonable selection of cutting amount, programming skills, and rapid control of dimensional accuracy. Comprehensive consideration.
First, programming skills
NC programming is the basic work of NC machining. The pros and cons of programming the workpiece machining program directly affect the final machining accuracy and efficiency of the machine tool. It can start from the clever use of inherent programs, reducing the cumulative error of the CNC system, and the flexible use of main programs and subprograms.
1. Flexible use of main programs and subprograms
In the processing of complex molds, a single mold with multiple pieces is generally used for processing. If there are several identical shapes on the mold, the relationship between the main program and the subprogram should be flexibly used, and the subprogram is repeatedly called in the main program until the processing is completed. Not only can ensure the consistency of processing size, but also improve its processing efficiency.
2. Reduce the cumulative error of the CNC system
Generally, the incremental method is used to program the workpiece. It is processed based on the previous point. In this way, the continuous execution of multiple sections of the program will inevitably generate a certain cumulative error. Therefore, try to use the programming method when programming, so that each program section uses the workpiece origin. As a benchmark, this can reduce the cumulative error of the CNC system and ensure the machining accuracy.
Machining accuracy is mainly used to produce products. Machining accuracy and machining errors are terms used to evaluate the geometric parameters of the machining surface. However, the actual parameters obtained by any machining method will not be accurate. From the perspective of the function of the part, as long as the machining error is within the tolerance range required by the part drawing, it is considered that the machining accuracy is guaranteed.
Machining accuracy refers to the actual geometric parameters (size, shape, and position) after the part is processed. You want to learn UG programming to receive learning materials. The group 496610960 can help you meet the ideal geometric parameters. The difference between them is called processing error. The size of the processing error reflects the level of processing accuracy. The larger the error, the lower the machining accuracy, and the smaller the error, the higher the machining accuracy. The following briefly introduces the methods to improve the accuracy of workpiece processing:
First, adjust the process system
(1) Trial cutting adjustment By trial cutting-measuring the size-adjusting the cutting amount of the tool-cutting by cutting-retry cutting, and so on until the required size is reached. This method has low production efficiency and is mainly used for single-piece small batch production.
(2) The adjustment method obtains the required size by adjusting the relative positions of the machine tool, fixture, workpiece and tool in advance. This method has high productivity and is mainly used for mass production.
Second, reduce machine error
(1) The rotation accuracy of the bearing should be improved:
① Use high-precision rolling bearings;
② Adopt high-precision multi-oil moving bearing;
③ Adopting high-precision static bearing
(2) Improve the accuracy of bearing-related parts:
① Improve the machining accuracy of box support holes and spindle journals;
②Improve the machining accuracy of the surface matching the bearing;
③ Measure and adjust the radial runout range of the corresponding parts to compensate or cancel the error.
(3) Proper pretensioning of rolling bearings:
① Can eliminate the gap;
② Increase bearing stiffness;
③ homogenize rolling body errors.
(4) The spindle rotation accuracy is not reflected on the workpiece
Third, reduce the transmission error of the transmission chain
(1) The number of transmission parts is small, the transmission chain is short, and the transmission accuracy is high;
(2) The use of down-speed transmission is an important principle to ensure transmission accuracy, and the closer to the end of the transmission pair, the smaller the transmission ratio should be;
(3) The accuracy of the end piece should be higher than other transmission pieces.
Fourth, reduce tool wear
(1) The tool must be re-sharpened before the tool size wear reaches the sharp wear stage
(2) Use special cutting oil for sufficient lubrication
(3) The material of the tool should meet the process requirements
Five, reduce the force deformation of the process system
(1) Improve the stiffness of the system, especially the weakness of the weak links in the process system;
(2) Reduce the load and its changes
Six, reduce the thermal deformation of the process system
(1) Reduce heat generation and isolate heat sources
(2) Equilibrium temperature field
(3) Use reasonable machine tool component structure and assembly benchmark
(4) Accelerate heat transfer equilibrium
(5) Control the ambient temperature
Seven, reduce residual stress
(1) Increase the heat treatment process to eliminate internal stress;
(2) Arrange the process reasonably.
The above is the method to reduce the error in processing the workpiece, and the reasonable arrangement of the process can effectively improve the precision of the workpiece.
2. Set up processing routes reasonably
Reasonable setting of processing routes and processing sequences is an important basis for optimizing the programming of workpiece processing programs. It can be considered from the aspect of machining trajectory and feeding method.
In the course of NC milling of workpieces, if you want to learn UG programming and get learning materials in group 496610960, you can help you choose the appropriate feeding method based on the technical requirements of the workpiece to ensure the cutting accuracy and processing efficiency of the workpiece. When milling the outer contour of a flat workpiece, the cutting-in and cutting-out routes of the tool should be arranged. Cut in and out along the extension of the contour curve as much as possible to avoid knife marks at the junction. At the same time, milling or down milling should be selected according to the situation of the workpiece during milling.
Selection and correct installation of cutters
No matter it is CNC machining or ordinary machining, the tool directly affects the workpiece, so its selection and installation are the main factors of workpiece machining accuracy and surface quality. In particular, the workpiece is processed on CNC machining, and the tools are stored in the tool magazine in advance. Once the processing is started, they cannot be replaced at will. Therefore, the general principle of tool selection is: easy installation and adjustment, good rigidity, high durability and precision.
Fourth, the reasonable choice of cutting amount
The determination of the cutting amount is an important content of the NC machining process. Its size is an important parameter of the main movement and feed movement of the machine tool, and it has an important influence on the workpiece machining accuracy, machining efficiency and tool wear. The choice of cutting amount includes cutting speed, back feed amount and feed amount. The basic selection principle is: under the condition that the rigidity allows, take a larger cutting depth for roughing to reduce the number of passes and improve the productivity of the workpiece; generally, take a smaller cutting depth for finishing to obtain a higher surface quality.