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Factors affecting CNC machining efficiency

To see what is the efficiency factor of CNC machining, we must first know that CNC machining center belongs to numerical control equipment, which is mainly operated by the computer programming command of technical engineers. In the process of production, how to improve the efficiency of CNC processing

  1. Selection of machine tools

Before arranging CNC parts processing, we must ensure the weight that the worktable can bear and consider the smooth processing of mechanical parts. Nowadays, the efficiency of production and processing has a direct impact on whether small and medium-sized processing enterprises can make profits. If the machine tool table can not meet the requirements of use, the processing efficiency will be reduced, and the accuracy of the machine tool itself will also be affected.

  1. Reasonable processing steps

For the machining industry, it can be said that reasonable production and processing technology is one of the important steps. CNC parts processing is very difficult, so we must choose a reasonable processing route, which can save time and improve the production and processing efficiency. On the contrary, if the selection of processing technology is unreasonable, the production efficiency will be reduced.

  1. Small batch processing

Many customers ask whether small batch processing is possible. When small batch and large batch parts are processed, the advantage of precision CNC processing is very obvious, which saves the time of programming and machine adjustment. Only need to clamp parts repeatedly, the production and processing efficiency can be improved many times!

The above is the factor of CNC processing rate.

ken. tang@chengcg.com

Introduction to machining tolerance of CNC parts

A precision parts processing drawings will have dimensions, special position machining accuracy requirements, that is, positive and negative tolerance. The marked tolerance is to ensure that the actual geometric parameters are consistent with the dimensions specified on the drawing in the process of precision parts processing, and the degree of inconsistency between them is called processing error. In order to ensure the accuracy tolerance and avoid the machining error, the following three points should be paid attention to

  1. Benchmark:

According to the shape of different parts, the same datum plane can be selected for processing to ensure that the clamping of parts in the processing process can reduce a certain error range, which is the importance of datum plane.

  1. Shape:

For different drawings provided by our customers, the workpiece with special shape can’t be clamped normally. At this time, we can consider designing clamping fixture for positioning processing and selecting datum plane. Its main function is to assist the processing to meet the accuracy requirements and improve the production and processing efficiency.

  1. Technology

In the precision machining industry, some people say that the drawing processing technology is an art, reasonable technology will save a lot of time, but also can improve the efficiency of production and processing. So a reasonable process is very important.

  1. Machine tool:

Previous articles have also mentioned that the accuracy of the machine tool itself will affect the error, because there are several kinds of errors of the machine tool itself, mainly including the head spindle rotation error, guide rail error and transmission chain error.

ken. tang@chengcg.com

Structure of CNC machining

The system structure principle of CNC machining, in the CNC machining process, can logically process the program with control code or other symbol instructions, and decode it, so as to make the machine move and process mechanical parts, collectively referred to as CNC machining.

The structure of CNC machine tool is as follows

  1. Main machine, which is the theme of CNC machine tools, including machine body, column, spindle, feed mechanism and other mechanical parts. He is used to complete a variety of cutting precision parts processing.
  2. Numerical control device is the core of CNC machine tool, including hardware and corresponding software, which is used to input digital part program, complete input information storage, data transformation, interpolation operation and realize various control functions.
  3. Driving device, which is the driving part of CNC machine tool actuator, including spindle driving unit, feed unit, spindle motor and feed motor. Under the control of the numerical control device, he realizes the spindle and feed drive through the electric or electro-hydraulic servo system. When several feed linkage, can complete the positioning, straight line, plane curve and space curve processing.
  4. Auxiliary device refers to some necessary supporting parts of CNC machine tool to ensure the operation of CNC machine tool, such as cooling, chip removal, lubrication, lighting, monitoring, etc. It includes hydraulic and pneumatic device, chip removal device, exchange table, numerical control turntable, numerical control dividing head, cutting tool, monitoring and detection device, etc.
  5. Programming and other auxiliary equipment, which can be used to program and store CNC parts outside the machine.

The above is the structure of CNC processing. In the machining industry, precision CNC processing greatly improves production efficiency. It has the following advantages: (1) it can guarantee the accuracy and surface roughness of the workpiece to be machined; ② It can shorten the processing route, reduce the empty travel time and improve the processing efficiency; ③ The workload of numerical calculation should be simplified as much as possible, and the machining program should be simplified; ④ For some repeated programs, subroutines should be used.

ken. tang@chengcg.com

Spindle is an important factor of CNC lathe

The important factors determining the spindle of CNC machine tool

Machine tool spindle refers to the machine tool to drive the workpiece or tool rotation axis. It is usually composed of spindle, bearing and transmission parts (gear or pulley). In addition to planer, broaching machine and other machine tools whose main motion is linear motion, most machine tools have spindle components. The motion accuracy and structural stiffness of spindle components are important factors to determine the machining quality and cutting efficiency. The main indexes to measure the performance of spindle components are rotation accuracy, stiffness and speed adaptability.

For the modular design of CNC machine tools, simplify the structure of machine tools, improve the performance of machine tools

a. Simplify the structure and promote the modularization of machine tool structure

Motorized spindle can form standardized and serial products according to the use, structure, performance parameters and other characteristics, which can be selected by the host machine, so as to promote the modular structure of the machine tool.

b. Reduce the cost of machine tools and shorten the development cycle of machine tools

On the one hand, standardized and serialized motorized spindle products are easy to form specialized and large-scale production, which can also shorten the development cycle of machine tools and adapt to the current rapid and changeable market trend.

c. Improve machine performance and reliability

The reliability of CNC machine tools with motorized spindle structure is improved because of its simplified structure and reduced transmission and connection links; With mature technology, perfect function, excellent performance and reliable quality, the performance and reliability of the machine tool are further improved.

d. Realize the special requirements of some high-grade CNC machine tools

Some high-end CNC machine tools, such as parallel motion machine tools, pentahedral machining centers, small hole and super small hole machining machines, must use motorized spindle to meet the perfect functional requirements.

ken. tang@chengcg.com

ypes of machining methods

In the field of mechanical processing industry, most of the manufacturers are engaged in the processing of ordinary milling machines and lathes, and there are also precision machining manufacturers. Because it is a more detailed industry, its production corresponds to the processing of other machine tools, the processing process is relatively complex, and the requirements for product quality error are very strict, Ordinary machine tools can’t do it. The following is a brief description of the precision machining method:

Classification of machining process: corresponding to different mechanical parts processing, there are different processing machine tools, the most common are lathe (general lathe), milling machine (general milling), grinder, wire cutting, desktop lathe and so on. The processing of complex mechanical equipment parts needs high precision machine tools.

The method of precision machining mainly depends on the process steps: the processing technology of precision parts is reasonable, improving the quality of parts processing, at the same time, it can also create efficiency for enterprises. Generally provide precision machining machine tools and equipment are: CNC processing (computer gong), CNC lathe, compound turning and milling processing, precision parts with special accuracy requirements, can be processed with four axis, five axis CNC, and finally according to the customer’s drawing processing requirements!

The above is how many kinds of precision machining methods, thank you for your attention!

ken. tang@chengcg.com

Plane accuracy of ordinary milling machine

Completely rely on technicians independently operate x, y, Z axis coordinates, simple mechanical equipment parts, hardware parts hole, plane, step, keyway processing, such processing machine is called ordinary milling machine. In the field of mechanical processing industry, the status of ordinary milling machine was very important in the early days. At that time, the CNC processing equipment was not extended, and the processing of mechanical parts, hardware parts, fixture and fixture all depended on ordinary milling machine, lathe and grinder. At any time, the mechanical equipment manufacturing industry continued to progress, and the ordinary processing machine tool could not meet the needs of the mechanical processing industry.

At present, the ordinary milling machine is mainly for single piece, small batch parts processing, although the processing accuracy requirements are not high, but has advantages. Especially for the plane machining of mechanical equipment parts, it can be rough machining, finish machining, and can also help to clamp the workpiece. The precision of the plane machining of the workpiece depends on the size of the workpiece platform. Generally, the plane machining precision of mechanical parts can be controlled within 0.1 mm, and finally it can be processed according to the customer’s drawing.

The above is the ordinary milling machine processing plane precision can achieve how much, thank you for sharing!

ken. tang@chengcg.com

Hardness requirements of CNC machining materials

In the field of mechanical processing industry, the hardness requirements of non-standard accessories, fixture, automation equipment parts and so on are determined according to the selected materials. Generally, aluminum alloy, POM saigang, Q235, brass and other materials do not need quenching treatment, so they are suitable for machining fixture accessories and mechanical equipment parts and so on. There are no material hardness requirements for parts processing.

In metal materials, there are many materials, such as Cr12, 45, 50, SKD11, SKD61, which can meet certain hardness requirements according to the surface heat treatment process, such as equipment shaft fittings or mold blade, The main role is to extend the life of spare parts and achieve the corresponding effect! In the machining line, we always choose different heat treatment process to achieve the required hardness according to the processing process requirements on the production drawings. The hardness requirement of equipment parts after processing directly affects the selection of materials.

The above is the concept of material hardness requirements for mechanical parts processing, thank you for sharing.

ken. tang@chengcg.com

Methods of improving CNC machining accuracy

In the machining process of mechanical parts, the quality precision control firstly improves the geometric precision of the machine tool, the precision of measuring tools and tools, controls the error caused by the force and thermal deformation of the process system, reduces the deformation error caused by the cutting tool wear and internal stress, and reduces the measurement error as far as possible, all of which belong to the direct reduction of the original error. Improve the machining accuracy of mechanical parts, analyze the original errors of machining errors, and take corresponding measures to solve the main original errors according to different situations. For the processing of precision mechanical parts, the geometric accuracy, stiffness and thermal deformation of precision machine tools should be improved as much as possible; For the parts with forming surface, the main problem is how to reduce the shape error and installation error of forming tool.

The method of error compensation can be used to control the influence of some original errors in the processing of mechanical parts. Sometimes a new kind of original error will be created by human, so as to compensate or offset the original error inherent in the original process system, so as to reduce the machining error and improve the machining accuracy. Using one original error to partially or completely offset the original error or another original error. In order to improve the machining accuracy of a batch of mechanical parts, the method of dividing some original errors can be adopted. For the part surface with high machining accuracy, the method of homogenizing the original error step by step can be adopted in the process of continuous trial cutting.

After the basic understanding of the machining process, according to the error reflection law, the workpiece size of the blank or process is divided into n groups according to the size, and the size range of each group of workpiece is reduced to the original 1n. Then, according to the error range of each group, the accurate position of the cutter relative to the workpiece is adjusted respectively, so that the center of the size dispersion range of each group of workpieces is basically the same, so that the size dispersion range of batch workpieces is greatly reduced.

The process of reducing and equalizing the original error of machined surface by machining. The principle of homogenization is to find out the differences between the closely related workpieces or tool surfaces through mutual comparison and inspection, and then carry out mutual correction machining or benchmark machining.

In the machining process, the original error is transferred from the error sensitive direction to the error insensitive direction, and the original error is transferred to the error insensitive direction. The degree of various original errors reflected in the machining errors of parts is directly related to whether they are in the error sensitive direction. If we try to transfer it to the non sensitive direction of machining error, the machining accuracy can be greatly improved. Transfer the original error to other aspects that have no effect on the machining accuracy.

The above is to share how to improve the machining accuracy of mechanical parts, thank you for your attention!

ken. tang@chengcg.com

Introduction of CNC machining accuracy

In the process of machining precision mechanical parts, there are the following points to control the machining accuracy: geometric accuracy: geometric accuracy refers to the accuracy of the geometric shape of each surface or axis of the component, such as whether the line is straight, whether the surface is flat, whether the normal section on the cylinder is round, etc. The smaller the number of geometric tolerance is, the higher the shape accuracy is; Dimensional accuracy: dimensional accuracy refers to the accuracy of the size of parts after processing, expressed by “dimensional tolerance”. When the dimensions of parts are the same, the higher the accuracy is, the smaller the tolerance number is; Position accuracy: position accuracy refers to the accuracy of the mutual position between the surfaces of components, such as whether the two planes are parallel, vertical, and whether the two axes are coaxial, which is expressed by “position tolerance”. Hold these points, precision machining accuracy of mechanical parts is easier to control.

The above is the processing precision of precision mechanical parts, thank you for sharing!

ken. tang@chengcg.com

Basic steps of CNC processing quotation

The basic steps of quotation for mechanical parts processing are as follows: raw materials + processing time + mechanical wear and tear + surface treatment + packaging fee + tax = price. Quotation for mechanical processing is a relatively technical work, which requires not only rich machining technology, but also a certain understanding of machining process. Honghai machinery has many years of experience in machining mechanical parts. Now let’s look at the basic steps of quotation for machining mechanical parts

Calculate the processing cost of mechanical parts. First of all, consider the various processes and related aspects in the machining process, and take the machining process as the starting point to calculate the processing cost, and the price of raw materials should also be calculated clearly; Thirdly, clear processing ideas and process arrangement are set for the machining of mechanical parts, and each process is analyzed in depth. The processing cost is calculated according to the working hours required by each process and its price; How much is the surface treatment fee? Then according to the proportion, plus the packaging and transportation, management costs, tooling tools, machine tool wear, profit can be regarded as the machining quotation; Finally, with 17% VAT, the price is equal to the machining price.

For example, in the case of large quantities of parts, the processing price is more favorable, because the efficiency of processing large quantities of parts will be improved, thus reducing the cost. The above is the basic steps to share the quotation of mechanical parts processing, thank you for your attention!

ken. tang@chengcg.com