With the arrival of the world's fourth industrial revolution, and the continuous development of science and technology and social production, mechanical manufacturing technology has undergone profound changes, the structure of mechanical products is more and more reasonable, and its performance, accuracy and efficiency are increasingly improved, so the production equipment of processing mechanical products has put forward high performance, high precision and high automation requirements. In order to solve the problem that ordinary machine tools can not be produced, to achieve single and small batch production, especially the automatic processing of some complex parts, CNC machining came into being.

Although, at present, China has become a processing country, precision parts processing plants all over the country. According to the data of the General Administration of Customs of China, in January and February 2023, the cumulative export volume of China's machine tools reached 2364123 units (2,364,100 units), from high-end CNC customized precision parts to ordinary standard products can achieve standardized mass production, the application of CNC technology can realize the automatic processing of parts and improve production efficiency. Especially in the automotive manufacturing, aerospace, electronic equipment manufacturing and other fields, the application of CNC technology has great potential. The application of CNC technology can realize the automatic processing of parts and improve production efficiency. Especially in the automotive manufacturing, electronic equipment manufacturing and other fields, the application of CNC technology has great potential.

CNC machining is widely used in the field of automotive parts, involving the engine, transmission, chassis, braking system, steering system and other aspects. However, no matter in any field of precision machining, achieving high precision and high speed is an important competitive means to obtain user orders.



The following are some specific applications of CNC machining in the field of automotive parts:

Engine parts machining: CNC machining can be used to manufacture various parts of the engine such as cylinder block, crankshaft, connecting rod, valve seat, etc., which require high precision and high strength.



1.Transmission parts processing: CNC machining can be used to manufacture various parts of the transmission system such as transmission gears, clutches, transmission shafts, etc., which require high precision and high strength.

2.Brake parts processing: CNC machining can be used to manufacture various parts of the brake system such as brake discs, brake pads, brakes, etc., which require high precision and high quality.

3.Steering parts processing: CNC machining can be used to manufacture various parts of the steering system such as steering gear, steering rod, steering machine, etc., these parts need high precision and high strength.



With the continuous development of CNC machining technology and the expansion of application fields, whether it is automobile body design or automobile internal electronic parts processing, the application range of CNC custom machining technology in the field of automation will be more and more extensive. In the future, CNC machining technology will continue to play an important role in the automotive manufacturing field.

Precision machinery parts processing plays a crucial role in various industries, including aerospace, automotive, medical, and manufacturing.Precision machinery parts have specific requirements to ensure optimal performance.One crucial aspect is the material used for processing. If the hardness of the material being processed surpasses that of the lathe tool, it can potentially cause irreparable damage.Therefore, it is essential to select materials that are compatible with precision machining.





So
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what are the specific requirements for precision machinery parts processing?




1. Material Strength and Durability

One of the key requirements of precision machinery parts processing is material strength and durability.Machinery parts often undergo significant stress and pressure during operation, and the selected materials must be able to withstand these forces without deforming or breaking.For example, aerospace components require materials with high strength-to-weight ratios, such as titanium alloys, to ensure structural integrity and reliability.

2. Dimensional Stability

Precision machinery parts must maintain their dimensional stability even under extreme operating conditions.The materials used in their processing should possess low thermal expansion coefficients, allowing the parts to retain their shape and size without warping or distorting due to temperature fluctuations.Steels with low thermal expansion coefficients, such as tool steel or stainless steel, are commonly preferred for precision machinery parts subjected to varying thermal conditions.

3.Wear and Corrosion Resistance

Precision machinery parts often interact with other components or environments that can cause wear and corrosion.The materials chosen for their processing should exhibit excellent wear resistance to withstand constant friction and minimize surface damage.Additionally, corrosion resistance is crucial to ensure the longevity of the parts, especially in industries where exposure to moisture, chemicals, or harsh environments is common.Materials such as hardened steel, stainless steel, or certain grades of aluminum alloys are frequently utilized to enhance wear and corrosion resistance.

4.Machinability

Efficient and precise machining is a critical factor in the manufacturing of precision machinery parts.The material selected for processing should possess good machinability, allowing it to be easily cut, drilled, or shaped into the desired form with minimal tool wear.Materials like aluminum alloys with excellent machinability properties are often preferred for their versatility and ease of shaping into complex geometries.

5.Thermal Conductivity

Thermal management is significant in precision machinery parts processing, as excessive heat can adversely affect performance and increase the risk of failure.Materials with high thermal conductivity, such as copper alloys or certain grades of aluminum, help dissipate heat efficiently, preventing localized temperature rise and ensuring optimal operating conditions.

6.Cost-Effectiveness

While meeting the specific requirements is crucial, cost-effectiveness is also an important consideration in precision machinery parts processing.The selected materials should strike a balance between performance and cost, ensuring that the final product remains economically viable without compromising quality.Conducting a cost-benefit analysis and considering factors like material availability, processing complexity, and overall project budget can aid in making informed decisions regarding material selection.







The
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reasons why stainless steel material affects the machining accuracy of parts



Precision parts processed with stainless steel have the advantages of corrosion resistance, long service life and good mechanical and dimensional stability, and austenitic stainless steel precision parts have been widely used in medical, instrumentation and other precision machinery fields.



The reasons why stainless steel material affects the machining accuracy of parts

The exceptional strength of stainless steel, coupled with its impressive plasticity and noticeable work hardening phenomenon, result in a significant disparity in cutting force when compared to carbon steel. In fact, the cutting force required for stainless steel surpasses that of carbon steel by more than 25%.

At the same time, the thermal conductivity of stainless steel is only one-third of that of carbon steel, and the cutting process temperature is high, which makes the milling process deteriorate.

The growing machining hardening trend observed in stainless steel materials demands our serious attention. During milling, the intermittent cutting process leads to excessive impact and vibration, resulting in substantial wear and collapse of the milling cutter. Furthermore, the use of small-diameter end milling cutters poses a higher risk of breakage. Significantly, the decrease in tool durability during the milling process adversely affects the surface roughness and dimensional accuracy of precision parts machined from stainless steel materials, rendering them unable to meet the required standards.

Stainless steel precision parts processing precision solutions

In the past, traditional machine tools had limited success in machining stainless steel parts, particularly when it came to small precision components. This posed a major challenge for manufacturers. However, the emergence of CNC machining technology has revolutionized the machining process. With the aid of advanced ceramic and alloy coating tools, CNC machining has successfully taken on the complex task of processing numerous stainless steel precision parts. This breakthrough has not only improved the machining accuracy of stainless steel components but has also significantly enhanced the efficiency of the process. As a result, manufacturers can now rely on CNC machining to achieve precise and efficient production of stainless steel precision parts.





As an industry-leading manufacturer in precision machinery parts processing, HONSCN understands the significance of material requirements in delivering exceptional products. We prioritize using high-quality materials that meet all specific requirements, guaranteeing superior performance, durability, and reliability. Our team of experienced professionals meticulously evaluates each project's unique needs, selecting the most suitable materials to ensure customer satisfaction and industry-leading solutions.

In conclusion, precision machinery parts processing demands careful consideration of the materials used. From strength and durability to wear resistance and machinability, each requirement plays a vital role in achieving high-quality products. By understanding and meeting these specific material requirements, manufacturers can produce precision machinery parts that excel in performance, reliability, and longevity. Trust HONSCN for all your precision machinery parts processing needs, as we strive to deliver excellence through meticulous material selection and exceptional manufacturing expertise.

In the field of machining, after CNC machining process methods and division of processes, the main content of the process route is to rationally arrange these processing methods and processing sequence. In general, CNC machining of mechanical parts includes cutting, heat treatment and auxiliary processes such as surface treatment, cleaning and inspection. The sequence of these processes directly affects the quality, production efficiency and cost of the parts. Therefore, when designing CNC machining routes, the order of cutting, heat treatment and auxiliary processes should be reasonably arranged, and the connection problem between them should be solved.

In addition to the basic steps mentioned above, factors such as material selection, fixture design and equipment selection need to be considered when developing a CNC machining route. Material selection is directly related to the final performance of parts, different materials have different requirements for cutting parameters; The fixture design will affect the stability and accuracy of the parts in the process of processing; Equipment selection needs to determine the type of machine tool suitable for its production needs according to the characteristics of the product.







What do we have to do before arranging the CNC machining process route?


1, the processing method of precision machinery parts should be determined according to the characteristics of the surface. On the basis of familiar with the characteristics of various processing methods, mastering the processing economy and surface roughness, the method that can ensure the processing quality, production efficiency and economy is selected.

2, select the appropriate drawing positioning reference, according to the principle of crude and fine reference selection to reasonably determine the positioning reference of each process.

3, When developing the machining process route of the parts, it is necessary to divide the rough, semi-fine and finishing stages of the parts on the basis of the analysis of the parts, and determine the degree of concentration and dispersion of the process, and reasonably arrange the processing sequence of the surfaces. For complex parts, several schemes can be considered first, and the most reasonable processing scheme can be selected after comparison and analysis.

4, determine the processing allowance and process size and tolerance of each process.

5, select machine tools and workers, clips, quantities, cutting tools. The selection of mechanical equipment should not only ensure the quality of processing, but also be economical and reasonable. Under the conditions of mass production, general machine tools and special jigs should generally be used.

6, Determine the technical requirements and inspection methods of each major process.Determining the cutting amount and time quota of each process is usually decided by the operator for a single small batch production plant. It is generally not specified in the machining process card. However, in the medium batch and mass production plants, in order to ensure the rationality of production and the balance of rhythm, it is required that the cutting amount must be specified, and must not be changed at will.





cnc machining process arrangement


First rough and then fine

The processing accuracy is gradually improved according to the order of rough turning - semi-fine turning - fine turning. The rough lathe can remove most of the machining allowance of the workpiece surface in a short time, thereby increasing the metal removal rate and meeting the requirement of the uniformity of the allowance. If the residual amount left after the rough turning does not meet the finishing requirements, it is necessary to arrange a semi-finishing car for finishing. The fine car needs to ensure that the outline of the part is cut according to the drawing size to ensure the processing accuracy.

Approach first and then far

Under normal circumstances, the parts close to the tool should be processed first, and then the parts far away from the tool to the tool should be processed to shorten the moving distance of the tool and reduce the empty travel time. In the process of turning, it is beneficial to maintain the stiffness of the blank or semi-finished product and improve its cutting conditions.

The principle of internal and external intersection

For parts that have both an inner surface (inner cavity) and an outer surface to be processed, when arranging the processing sequence, the inner and outer surfaces should be roughed first, and then the inner and outer surfaces should be finished. Must not be part of the surface of the part (outer surface or inner surface) after processing, then processing other surfaces (inner surface or outer surface).

Base first principle

Priority should be given to the surface used as the finishing reference. This is because the more accurate the surface of the positioning reference, the smaller the clamping error. For example, when machining shaft parts, the center hole is usually machined first, and then the outer surface and end face are machined with the center hole as the precision basis.

The principle of the first and the second

The main working surface and assembly base surface of the parts should be processed first, so as to find out the modern defects on the main surface in the blank early. The secondary surface can be interspersed, placed on the main machined surface to a certain extent, before the final finishing.

The principle of the face before the hole

The plane outline size of the box and bracket parts is large, and the plane is generally processed first, and then the hole and other sizes are processed. This arrangement of processing sequence, on the one hand with the processed plane positioning, stable and reliable; On the other hand, it is easy to process the hole on the machined plane, and can improve the processing accuracy of the hole, especially when drilling, the axis of the hole is not easy to deviate.



Conclusion


When developing the machining process of parts, it is necessary to select the appropriate processing method, machine tool equipment, clamp measuring tools, blank and technical requirements for workers according to the production type of parts.

With the increasingly updated processing technology, CNC machining has also undergone a lot of changes. Many experts pointed out that in the future, CNC will be the mainstream processing mode. In the CNC machining process, the tool is the most important, today, we will understand the CNC tool in detail.




CNC machining tool concept



A tool is a tool used for cutting in mechanical manufacturing. Generalized cutting tools include both cutting tools and abrasive tools. The vast majority of knives are used for machines, but there are also hand tools. Since the tools used in mechanical manufacturing are basically used to cut metal materials, the term "tool" is generally understood as a metal cutting tool. The cutting tools used for cutting wood are called woodworking tools.


CNC machining tool



Tool classification

Cutting tools can be divided into five categories according to the form of the workpiece machined surface.

Cutting tools for processing various outer surfaces, including cutting tools for processing various outer surfaces, including turning tools, planing knives, milling cutters, outer surface broach and file, etc.

Hole processing tools, including drill, reaming drill, boring cutter, milling cutter and internal surface broach, etc.

Thread processing tools, including tap, die, automatic opening thread cutting head, thread turning tool and thread milling cutter.

Gear processing tools, including hob, gear shaper cutter, shaving cutter, bevel gear processing tool, etc.

Cutting tools, including inserted circular saw blade, band saw, bow saw, cutting tool and saw blade milling cutter, etc.

In addition, there are combination tools.


Hole cutting tool



Tool structure

The structure of various tools is composed of a clamping part and a working part. The clamping part and working part of the overall structure of the tool are done on the tool body; The working part of the tool (the tooth or blade) is mounted on the tool body.

The clamping part of the tool has two kinds of holes and handles. The tool with hole relies on the inner hole set on the spindle or mandrel of the machine tool, and transmits the torsional torque with the help of the axial key or the end key, such as the cylindrical milling cutter and the sleeve face milling cutter.

The tool with the handle is usually rectangular handle, cylindrical handle and conical handle three kinds. Turning tools, planing tools, etc. are generally rectangular handles; The conical handle withstands the axial thrust with the taper and transmits the torque with the help of friction. Cylindrical shank is generally suitable for smaller twist drill, end mill and other tools, cutting with the help of the friction generated when clamping torque transfer. The shank of many tools with handles is made of low alloy steel, and the working part is made of high speed steel welded to each other.



The basic properties that the tool material should have

1. High hardness

The hardness of the tool material must be higher than the hardness of the workpiece material to be machined, which is the basic feature that the tool material should have.

2. Sufficient strength and toughness

The material of the cutting part of the tool must withstand great cutting force and impact force when cutting. The bending strength and impact toughness reflect the ability of tool material to resist brittle fracture and edge breakage.

3. High wear resistance and heat resistance

The wear resistance of tool materials refers to the ability to resist wear. The higher the hardness of the tool material, the better the wear resistance; The higher the high temperature hardness, the better the heat resistance, the tool material at high temperature resistance to plastic deformation, anti-wear ability is also stronger.

4. Good thermal conductivity

Large thermal conductivity means good thermal conductivity, and the heat capacity generated during cutting is easily transmitted out, thereby reducing the temperature of the cutting part and reducing tool wear.

5. Good technology and economy

In order to facilitate manufacturing, the tool material is required to have good machinability, including forging, welding, cutting, heat treatment, grindability and so on. Economy is one of the important indexes to evaluate and promote the application of new tool materials.

6. Resistance to bonding

Prevent the workpiece and the tool material molecules under the action of high temperature and high pressure adsorption bond.

7. Chemical stability

It means that the tool material is not easy to react chemically with the surrounding medium at high temperature.

Tool coating

Aluminum alloy indexable inserts are now coated with hard or composite layers of titanium carbide, titanium nitride, alumina by chemical vapor deposition. The physical vapor deposition method that is being developed can be used not only for aluminum alloy tools, but also for high-speed steel tools such as drills, hobs, taps and milling cutters. As a barrier that prevents chemical diffusion and heat conduction, the hard coating slows down the wear rate of the tool during cutting, and the life of the coated blade is about 1 to 3 times higher than that of the uncoated blade.




How to choose a tool



Tool selection is carried out in the human-machine interaction state of NC programming. The tool and handle should be correctly selected according to the machining capacity of the machine tool, the performance of the workpiece material, the processing procedure, the cutting amount and other relevant factors.

The general principle of tool selection: easy installation and adjustment, good rigidity, high durability and accuracy. On the premise of meeting the processing requirements, try to choose a shorter tool handle to improve the rigidity of the tool processing. When selecting the tool, the size of the tool should be adapted to the surface size of the workpiece to be machined.

1. End milling cutter is often used to process the peripheral outline of plane parts.

2. When milling the plane, carbide blade milling cutter should be selected.

3. When processing convex and grooves, choose high-speed steel end milling cutter.

4. When processing the blank surface or roughing the hole, you can choose the corn milling cutter with cemented carbide blade.

5. For the processing of some vertical surface and variable bevel contour, ball end milling cutter, ring milling cutter, conical milling cutter and disk milling cutter are often used.

6. In the processing of free-form surface, because the cutting speed of the end of the ball head tool is zero, so in order to ensure the processing accuracy, the cutting line spacing is generally very dense, so the ball head is often used in the finishing of the surface.

7, flat head tool in the surface processing quality and cutting efficiency are better than the ball head knife, therefore, as long as the premise of ensuring but cutting, whether it is rough surface machining or finishing, should be preferred to choose flat head knife.

8. In the machining center, various tools are installed on the tool library, and the tool selection and tool change are carried out at any time according to the procedure. Therefore, the standard tool handle must be used in order to make the standard tool for drilling, boring, expanding, milling and other processes quickly and accurately installed on the machine spindle or tool library. The number of tools should be reduced as far as possible; After a tool is installed, it should complete all the processing parts that it can carry out; Rough finishing tools should be used separately, even if the same size specifications of the tool; Milling before drilling; Surface finishing is carried out first, and then 2D contour finishing is carried out. Where possible, the automatic tool change function of CNC machine tools should be used as much as possible to improve production efficiency.


Problems encountered in processing aluminum and solutions



Problems encountered in processing aluminum and solutions when processing pure aluminum, easy to stick knife analysis and solutions:

1. Aluminum material is soft in texture and easy to stick at high temperature;

2. Aluminum is not resistant to high temperature, easy to open;

3. Related to processing cutting fluid: good oil lubrication performance; Good water-soluble cooling performance; High dry cutting cost;

4. When processing pure aluminum, the end mill dedicated to aluminum processing should be selected: positive front Angle, sharp cutting edge, large chip discharge slot, 45 degrees or 55 degrees helix Angle;

5. The material of the workpiece and the CNC tool has a greater affinity.

6. Rough front tool processing soft materials.

Recommendation: Machine tool conditions are poor to good requirements are low to high, please use high-speed steel, coated polished carbide, PCD polycrystalline diamond and single crystal diamond.

7. Low speed can be avoided by cutting fluid, high speed oil mist lubrication, the effect can be improved, aluminum alloy suitable


Tool future development direction



Due to the high temperature, high pressure, high speed, and the parts working in the corrosive fluid medium, the application of difficult to process more and more materials, the automation level of cutting processing and the processing accuracy requirements are getting higher and higher. In order to adapt to this situation, the development direction of the tool will be the development and application of new tool materials; Further develop the vapor deposition coating technology of the tool, and deposit higher hardness coating on the matrix of high toughness and high strength, so as to better solve the contradiction between hardness and strength of the tool material; Further development of indexable tool structure; Improve the manufacturing accuracy of the tool, reduce the difference in product quality, and optimize the use of the tool.How to choose CNC aluminum alloy machining tool.

1 Tool change of hat type magazineThe fixed address tool change mode is mostly adopted, and the tool number is fixed corresponding to the tool seat number. The tool change action is realized by the lateral movement of the tool magazine and the up and down movement of the spindle, which is referred to as the spindle tool change mode for short. Because it has no tool change manipulator, the tool selection action cannot be preselected before the tool change action. The tool change instruction and tool selection instruction are generally written in the same program segment, and the instruction format is as follows:M06 T


When the command is executed, the tool magazine first turns the tool holder corresponding to the tool number on the spindle to the tool change position, and switches the tool on the spindle back to the tool holder, and then the tool magazine turns the tool specified in the command to the tool change position and changes the spindle.For this tool magazine, even if TX x is executed before M06, the tool cannot be preselected, * the action of final tool selection is still executed when M06 is executed. If there is no TX X in front of M06, the system will give an alarm.2 Tool change of disc and chain magazine
Most of them use random address tool change mode. The corresponding relationship between tool number and tool seat number is random, but its corresponding relationship can be remembered by NC system. The tool change of this tool magazine depends on the manipulator. The action of the command and tool change is: the tool command TX controls the rotation of the tool magazine and turns the selected tool to the tool change working position, while the tool change command M06 controls the action of the tool change manipulator to realize the tool exchange between the spindle tool and the tool change position of the tool magazine. The tool selection command and tool change command can be in the same program segment or written separately. The actions corresponding to tool selection and tool change command can also be operated simultaneously or separately. The instruction format is as follows:
Tx x M06;When the command is executed, the tool magazine first turns the TX tool to the tool change position, and then the manipulator exchanges the tool of the tool magazine with the tool of the spindle to realize the purpose of changing the TX tool to the spindle.After reading the above two methods, it can be seen that method 2 overlaps the tool selection action with the machining action, so that when changing the tool, it is not necessary to select the tool and change the tool directly, which improves the work efficiency.
As mentioned earlier, the tool change command of the tool magazine is related to the machine tool manufacturer. For example, some tool magazines require that not only the Z axis must return to the tool change point, but also the Y axis must return to the tool change point. The program format is as follows:
When writing the instructions of tool selection and tool change in the same program section, the execution rules of tools from different manufacturers may also be different. If any, regardless of the writing order, the rules of tool selection and tool change shall be followed. Some rules stipulate that the tool selection command must be written before the tool change command is executed. Otherwise, the action is to change the tool first and then select the tool, as shown in the above program. In this case, if the tool selection command is not written before the M06 command is executed, the system will give an alarm.