Tips for improving the production efficiency of CN

2022-07-25
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Tips for improving the production efficiency of CNC machine tools

in the actual production process, we will find that the same CNC machine tool is operated by different personnel, and the production efficiency varies greatly within the same working time. The processing capacity of many CNC machine tools can not be fully reflected and can not play its best role. In the process of using, only by fully considering the various factors that affect the production efficiency of CNC machine tools and trying to improve the production efficiency of CNC machine tools, can the production capacity of CNC machine tools be brought into full play

1. In order to improve the production efficiency of CNC machine tools, it is necessary to carefully analyze the parts processed by CNC machine tools and clarify the technical requirements of materials, structural characteristics, geometric tolerance requirements, roughness, thermal treatment, etc. Then on this basis, a reasonable milling process and a simple processing route are selected

formulation of processing technology: generally, a part can have several different processes. The process of the part is different, and its production efficiency, processing cost and processing accuracy often have significant differences. Therefore, we should try to improve the production efficiency and reduce the production cost according to the specific conditions of production, and formulate a reasonable processing technology on the premise of ensuring the processing quality of the part

determination of processing route: correct and concise processing route is the basis for ensuring processing quality and improving efficiency. When selecting the processing route of parts, the principle of determining the processing route must be observed in order to achieve the purpose of improving production efficiency. The principles for determining the processing route are as follows: it should be able to meet the requirements of machining accuracy and surface roughness of parts, and the efficiency should be high; The shortest processing route should be made as far as possible, which can not only reduce the program segment, but also reduce the tool empty travel time; The numerical calculation shall be simple and the number of program segments shall be small to reduce the programming workload. In addition, when determining the processing route, it is also necessary to consider the machining allowance of the workpiece and the rigidity of the machine tool and cutting tool, and determine whether to complete the processing by one-time tool feeding or multiple tool feeding. At the same time, try to achieve one-time clamping, multi-directional processing and one-time processing. In this way, the installation times of the workpiece can be reduced, and the time of handling and clamping can be effectively shortened. In this way, the machining efficiency can be effectively improved and the position accuracy requirements of parts can be well ensured

2. Select appropriate tools to improve the cutting efficiency of CNC milling machine

the selection of tools should consider the processing capacity of CNC machine tools, process content, workpiece materials and other factors. The cutting tools selected for CNC machine tools not only require high hardness, high wear resistance, sufficient strength and toughness, high heat resistance and good processability, but also require stable size and convenient installation and adjustment. Therefore, new high-quality materials should be used to manufacture NC machining tools, and the tool parameters should be optimized to make the size of the tool adapt to the surface size and shape of the workpiece to be machined. So, how to choose the right cutting tool

(1) select the appropriate tool

in the cutting process of CNC machine tools, the role of metal cutting tools is extremely important. The materials used to manufacture cutting tools must have high hardness, wear resistance and heat resistance, sufficient strength and toughness, good thermal conductivity and processability, and good economy. In the process of selecting tools, on the premise of meeting the processing requirements of parts, try to select tools with larger diameter, which have better strength and toughness; In the same process, the number of tools selected shall be as few as possible to reduce the number of tool changes; Try to select general standard tools, and do not use or use less special non-standard tools

(2) reasonably determine the tool setting point

the tool setting point is the starting point of the tool relative to the workpiece when machining parts on the NC machine tool. It is also called "program starting point" or "starting point to point". The selection of tool setting points must comply with the following principles: it is easy to use digital processing and simplify programming; it is easy to align on the machine tool, and the processing is easy to check; the resulting processing error is small. The position of tool setting points can be selected on the workpiece or outside the workpiece (such as fixture or machine tool) However, it must have a certain dimensional relationship with the positioning datum of the part. The tool setting point shall be selected on the design basis or process basis of the part as far as possible. For example, for the workpiece positioned by the hole, the center of the hole can be selected as the tool setting point. The position of the tool is aligned with this hole, Make "in place point" and "tool setting point" Coincidence. In this way, it can better improve the efficiency of the wood-based panel testing machine, which is also applicable to the testing knife of other materials, and ensure the processing quality

3. Reasonably install and clamp the workpiece, and improve the clamping speed

when machining the workpiece on the NC machine tool, the positioning and installation stress of the workpiece will not affect the accuracy, so as to unify the design reference, process reference and programming calculation reference; Reduce the clamping times as much as possible, and process all the surfaces to be machined after one-time positioning and clamping as much as possible; Avoid using manual adjustment processing scheme to give full play to the efficiency of CNC machine tools

when cutting with CNC machine tools, comprehensive consideration should be given to the positioning and clamping design of parts, as well as the selection and design of furniture. When designing furniture, it is necessary to ensure that the coordinate direction of the furniture is relatively fixed with that of the machine tool. Secondly, coordinate the dimension relationship between parts and machine tool coordinate system. At the same time, we should also consider:

(1) when the production batch of parts is small, we should try to use combined fixtures, adjustable fixtures and general fixtures to shorten the production preparation time and save production costs

(2) the use of special fixtures should be considered only in mass production, and the structure should be simple

(3) parts shall be loaded and unloaded quickly, conveniently and reliably to shorten the downtime of the machine tool

(4) all parts and components on the fixture shall not interfere with the machining of parts' surfaces by the machine tool

(5) when selecting tooling, it shall be conducive to tool exchange to avoid interference and collision

(6) multi position and multi piece fixtures can also be used in batch production to improve processing efficiency

4. Reasonably select cutting parameters to improve cutting efficiency of machining allowance

cutting parameters include spindle speed, cutting depth and feed speed. When selecting the cutting parameters of the NC milling machine, if it is rough machining, it is generally to improve the productivity, but also to consider the economy and processing cost. You can choose a larger cutting depth and feed speed; In case of semi finishing and finishing, efficiency, economy and processing cost should be considered on the premise of ensuring processing quality; Set the feed speed as high as possible when the tool moves in the short range. The specific value shall be determined according to the machine tool manual, cutting parameter manual and experience

5. Implement the tool pre adjustment and automatic wolf measurement to reduce the machine adjustment time

many different tools are often used in the machining process of CNC machine tools. If the tools cannot be adjusted in advance, the operator needs to install each tool on the spindle and slowly determine its exact length and diameter of the experimental machines produced by Jinan new era Gold Testing Instrument Co., Ltd. over the years. Then ouyangming said that it was manually input through the keys on the CNC control surface. If the tool setting instrument is used, it can accurately measure the diameter and length of the tool, reduce the occupation time of the machine tool, improve the first piece qualification rate, and greatly improve the production efficiency of the CNC milling machine

6. Flexible use of various auxiliary functions and macro programs of the NC machine tool

the NC machine tool has the function of tool radius and length compensation. The tool size error can be compensated by changing the tool compensation method. The layered milling and rough and finish machining can be realized with the same processing program or used to improve the processing accuracy, and the matching parts can be processed with the same processing program

the biggest feature of using macro programs is that regular shapes or sizes are represented by the shortest program, and when the machine tool executes such programs, it is faster and more responsive than the programs generated by cad/cam software. Macro programs can use variables and assign values to variables. Variables can be calculated, program operation can jump, and modular processing programs can be formed. During application, only part information and processing parameters need to be input into the call statements of corresponding modules, which greatly shortens the programming and input time

the NC machine tool also has fixed cycle function, subroutine function, mirror image processing function and rotating lamp function. Using these functions can avoid the input of long programs. If used properly, you can get twice the result with half the effort

7. Properly maintain the machine tool and extend the mean time between failures of the NC machine tool

the NC machine tool is a technology intensive product integrating mechanical, electrical, hydraulic, pneumatic, computer technology, control technology, detection and measurement technology, electric drive technology, PLC, etc. The normal maintenance of the NC machine tool by the user, timely troubleshooting and repair, can prolong the service life of various components, CNC systems and devices, and prevent the occurrence of accidents. It is the basic guarantee to give full play to the performance of the machine tool and work stably for a long time. Therefore, the automatic lubrication system shall be regularly inspected and cleaned, and grease and oil shall be added or replaced to keep the screw rod, guide rail and other moving parts in good lubrication condition and reduce the mechanical wear rate; Regularly check the accuracy of the machine tool and adjust it if necessary; When the oil-water filter and air filter are too dirty, there will be insufficient pressure, poor heat dissipation and other phenomena, which will cause failures. Therefore, they must be cleaned regularly to do a good job of cleaning and rust prevention; If the machine tool is not full or not used for a long time, it should be started regularly to let the machine tool run for a period of time

8. Strengthen information construction and personnel training to improve the use efficiency of CNC machine tools

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