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Machining process of mechanical parts refers to the methods and steps of mechanical parts processing, in the machining of mechanical parts must be based on the machining process of mechanical parts, to comply with the processing technology requirements of the parts. So do you know what the machining process of mechanical parts content and steps are? Today I will share with you! 1. Determine the type of blank The type of blank should be determined according to the material, shape and size of the part, and also consider the workpiece batch and production conditions. As shown in the figure, the diameter of the drive shaft is small, and the difference in the diameter of the outer circle of each section is not large, so the round steel can be selected for undercutting. The gear shaft shown in the figure, the diameter difference is large, in order to save materials and processing time, if the batch is large, but also has forging conditions, should choose to use forging blanks; otherwise, also choose round steel under the material. Bearing cover, the material is cast iron, the blank should be selected castings. Gear, the material is 40 steel, and the outer circle diameter is not large, small outer circle short, can choose round steel material. Gear, due to its outer circle and hole diameter are larger, a single piece can choose the corresponding thickness of steel plate gas section under the material, large quantities can be selected forgings, forging into a circular blank, so as to save materials, but also to reduce processing time, forging the mechanical properties of the blank is also better.   2. Determine the processing order of the parts Processing order should be determined according to the type of blank, structure, size, processing accuracy, surface roughness and heat treatment and other technical requirements. 3. Determine the processing process Determine the machine tools used in each process, workpiece clamping methods, processing methods, processing dimensions and inspection methods, including the next process left plus allowance. General small and medium-sized parts outside, inside the cylinder and plane are referred to a single margin, in a single piece of small batch production, the size of the blank is large to take the fire value, and vice versa, take the small value. Total margin: hand-shaped castings for 3-6mm; free forging or gas cutting parts for 3-7mm; round steel material for 1.5 ~ 2.5mm. process margin: semi-finishing car for 0.8 ~ 1.5mm; high-speed finishing car for 0.4-0.5mm.   4. Determine the amount of cutting and work time quota The cutting dosage of single-piece small batch production is generally selected by the producer himself, and the quota of man-hours is set by the management.   5. Fill in the process card With a brief description and process sketch to show the above content.

When engaged in the mechanical parts processing industry, safety is undoubtedly the most important issue that needs to be paid attention to. So do you know what are the precautions in the process of machining mechanical parts (before and after) in addition to safety issues? Today by the editor to share it with you! Precautions. 1. Strictly abide by the operating procedures and wear the required labor protection articles.   2. Be familiar with the drawings and related process requirements and fully understand the geometry and dimensional requirements of the parts to be processed.   3. Receive materials according to the material specifications required by the drawing process, and check whether the materials meet the requirements of the process.   4. Select the appropriate machining tool.   5. Prepare the required gauges for the machined parts.   6. Check if the equipment is normal and the safety protection is complete, fill the lubricating oil holes, and check the equipment in air operation. 7. Clamp and calibrate the workpiece, and clamp it reliably.   8. Normal processing according to the process requirements.   9. Do the process self-inspection.   10. After processing by mutual inspection, call the inspector special inspection.   11. After the operation is completed, immediately clean up the oil and chips on the equipment and the work site, the parts are neatly arranged.   12. Turn off the power and do the maintenance of the equipment.

In the field of mechanical parts processing industry, the purchase of suitable raw materials is the basis of processing, or buy poor quality parts to process, how can not process good mechanical parts. Do you know how to purchase mechanical processing parts? Today I will share with you the mechanical parts processing parts procurement skills! The procurement of parts for enterprises is also a science, the procurement of goods directly affects the quality and efficiency of enterprise products.   1. The unit supplying the parts must have ISO9000 certification to provide the required items 2. The supplied items must have the quality assurance sheet provided by the fingertip department of the unit. 3. The original material quality assurance sheet of the supplied items 4. The demander must examine and certify the management system of the supplier and include it in the list of qualified supplier units of the enterprise before using the items provided by the supplier.  

Titanium is a polycrystalline metal. It is a crystal form below 882 ℃. Its atomic structure is a close packed hexagonal lattice. From 882 ℃ to the melting point, it is a B crystal form, which is a body centered cubic lattice. Industrial pure titanium presents a phase in the metallographic structure. if the annealing is complete, it is an equiaxed single crystal lattice with the same size. Due to impurities, a small amount of B phase also exists in commercially pure titanium. It is basically distributed along the grain boundary. According to the new standard GB/T3620.1-2007, industrial pure titanium has nine brands, three TA1 types and two TA2-TA4 types. The difference between them is the purity. From the table, we can see that each brand of TA1-TA4 has a brand with the suffix ELI, which is the abbreviation of English low clearance element, which means high purity. Because Fe, C, N, H, O exist as interstitial elements in a-Ti, their content has a great impact on the corrosion resistance and mechanical properties of industrial pure titanium. The solid solution of C, N, O in titanium can cause great distortion of titanium lattice, and make titanium strongly strengthened and brittle. These impurities are brought in by raw materials during production, mainly the quality of titanium sponge. If you want to produce high-purity industrial pure titanium ingots, you must use high-purity sponge titanium. In the standard, the highest content of the six elements of the brand with ELI is lower than that of the brand without ELI. The revision of these standards is based on the international or western standards (our national standards are trying to move closer to the western countries, because many of our basic industries are still lagging behind them, and many old standards follow the former Soviet Union), especially in terms of impurity content and room temperature mechanical properties, the indicators of each brand are basically consistent with those of the international and western countries. This new standard mainly refers to ISO (international standard) surgical implants and American ASTM material standards (B265, B338, B348, B381, B861, B862 and B863). It also corresponds to ISO and American ASTM standards, for example, TA1 corresponds to Gr1, TA2 corresponds to Gr2, TA3 corresponds to Gr3, and TA4 corresponds to Gr4. This is conducive to clear reference of national standards in material selection and application of various industries, and also conducive to international exchanges in technology and commerce. Alloy grade, nominal chemical composition, impurities no more than Fe C N H O Other elements Single Sum TA1ELI industrial pure titanium 0.1 0.03 0.012 0.008 0.1 0.05 0.2 TA1 industrial pure titanium 0.2 0.08 0.03 0.015 0.18 0.1 0.4 TA1-1 industrial pure titanium 0.15 0.05 0.03 0.003 0.12 ---- 0.1 TA2ELI industrial pure titanium 0.2 0.05 0.03 0.008 0.1 0.05 0.2 TA2 industrial pure titanium 0.3 0.08 0.03 0.015 0.25 0.1 0.4 TA3ELI industrial pure titanium 0.25 0.05 0.04 0.008 0.18 0.05 0.2 TA3 industrial pure titanium 0.3 0.08 0.05 0.015 0.35 0.1 0.4 TA4ELI industrial pure titanium 0.3 0.05 0.05 0.008 0.25 0.05 0.2 TA4 industrial pure titanium 0.5 0.08 0.05 0.015 0.4 0.1 0.4 (Table I: Designation and chemical composition of titanium and titanium alloys) Two problems should be noted in the pure titanium table of this new standard. One is that in comparison with GB/T3620.1-1994 and GB/T3620.1-2007, the original TA0 changes to TA1, the original TA1 changes to TA2, the original TA2 changes to TA3, the original TA3 changes to TA4, and the original TA4 changes to TA28. The other is that with the increase of brand number, the content of these five impurity elements also increases, which means that the strength increases and the plasticity decreases gradually. One thing to note here is that Fe, the element, exists as an impurity, not as an alloy element. From the GB/T3620.1-2007 standard, we can see that the content of TA1~TA4 impurity elements increases gradually, but mainly Fe and O increase obviously, while C, N and H increase slightly. Industrial pure titanium is different from chemical pure titanium. Chemical pure titanium is used by scientific research institutions to conduct scientific research on some characteristics of pure metals, while industrial pure titanium is a material directly used in various industries, and contains more of the above five impurities than chemical pure titanium. Industrial pure titanium is characterized by its low strength, good plasticity, easy processing and forming, and can be stamped, Welding and machining properties are also good, and it has good corrosion resistance in various oxidation and corrosion environments. Therefore, more than 70% of the plates are industrial pure titanium, which is mainly used for the processing and molding of chemical reaction kettles and pressure vessels. Among these pure titanium grades, TA1 is the most widely used, followed by TA2. When it comes to industrial pure titanium, we must make it clear that the strength of industrial pure titanium cannot be improved by heat treatment. If the mechanical properties of a batch of pure titanium are low, don't imagine how to treat it to make it qualified. It's a waste of effort.

Titanium is a polycrystalline metal. It is a crystal form below 882 ℃. Its atomic structure is a close packed hexagonal lattice. From 882 ℃ to the melting point, it is a B crystal form, which is a body centered cubic lattice. Industrial pure titanium presents a phase in the metallographic structure. if the annealing is complete, it is an equiaxed single crystal lattice with the same size. Due to impurities, a small amount of B phase also exists in commercially pure titanium. It is basically distributed along the grain boundary. According to the new standard GB/T3620.1-2007, industrial pure titanium has nine brands, three TA1 types and two TA2-TA4 types. The difference between them is the purity. From the table, we can see that each brand of TA1-TA4 has a brand with the suffix ELI, which is the abbreviation of English low clearance element, which means high purity. Because Fe, C, N, H, O exist as interstitial elements in a-Ti, their content has a great impact on the corrosion resistance and mechanical properties of industrial pure titanium. The solid solution of C, N, O in titanium can cause great distortion of titanium lattice, and make titanium strongly strengthened and brittle. These impurities are brought in by raw materials during production, mainly the quality of titanium sponge. If you want to produce high-purity industrial pure titanium ingots, you must use high-purity sponge titanium. In the standard, the highest content of the six elements of the brand with ELI is lower than that of the brand without ELI. The revision of these standards is based on the international or western standards (our national standards are trying to move closer to the western countries, because many of our basic industries are still lagging behind them, and many old standards follow the former Soviet Union), especially in terms of impurity content and room temperature mechanical properties, the indicators of each brand are basically consistent with those of the international and western countries. This new standard mainly refers to ISO (international standard) surgical implants and American ASTM material standards (B265, B338, B348, B381, B861, B862 and B863). It also corresponds to ISO and American ASTM standards, for example, TA1 corresponds to Gr1, TA2 corresponds to Gr2, TA3 corresponds to Gr3, and TA4 corresponds to Gr4. This is conducive to clear reference of national standards in material selection and application of various industries, and also conducive to international exchanges in technology and commerce. Alloy grade, nominal chemical composition, impurities no more than Fe C N H O Other elements Single Sum TA1ELI industrial pure titanium 0.1 0.03 0.012 0.008 0.1 0.05 0.2 TA1 industrial pure titanium 0.2 0.08 0.03 0.015 0.18 0.1 0.4 TA1-1 industrial pure titanium 0.15 0.05 0.03 0.003 0.12 ---- 0.1 TA2ELI industrial pure titanium 0.2 0.05 0.03 0.008 0.1 0.05 0.2 TA2 industrial pure titanium 0.3 0.08 0.03 0.015 0.25 0.1 0.4 TA3ELI industrial pure titanium 0.25 0.05 0.04 0.008 0.18 0.05 0.2 TA3 industrial pure titanium 0.3 0.08 0.05 0.015 0.35 0.1 0.4 TA4ELI industrial pure titanium 0.3 0.05 0.05 0.008 0.25 0.05 0.2 TA4 industrial pure titanium 0.5 0.08 0.05 0.015 0.4 0.1 0.4 (Table I: Designation and chemical composition of titanium and titanium alloys) Two problems should be noted in the pure titanium table of this new standard. One is that in comparison with GB/T3620.1-1994 and GB/T3620.1-2007, the original TA0 changes to TA1, the original TA1 changes to TA2, the original TA2 changes to TA3, the original TA3 changes to TA4, and the original TA4 changes to TA28. The other is that with the increase of brand number, the content of these five impurity elements also increases, which means that the strength increases and the plasticity decreases gradually. One thing to note here is that Fe, the element, exists as an impurity, not as an alloy element. From the GB/T3620.1-2007 standard, we can see that the content of TA1~TA4 impurity elements increases gradually, but mainly Fe and O increase obviously, while C, N and H increase slightly. Industrial pure titanium is different from chemical pure titanium. Chemical pure titanium is used by scientific research institutions to conduct scientific research on some characteristics of pure metals, while industrial pure titanium is a material directly used in various industries, and contains more of the above five impurities than chemical pure titanium. Industrial pure titanium is characterized by its low strength, good plasticity, easy processing and forming, and can be stamped, Welding and machining properties are also good, and it has good corrosion resistance in various oxidation and corrosion environments. Therefore, more than 70% of the plates are industrial pure titanium, which is mainly used for the processing and molding of chemical reaction kettles and pressure vessels. Among these pure titanium grades, TA1 is the most widely used, followed by TA2. When it comes to industrial pure titanium, we must make it clear that the strength of industrial pure titanium cannot be improved by heat treatment. If the mechanical properties of a batch of pure titanium are low, don't imagine how to treat it to make it qualified. It's a waste of effort.

Machining error refers to the degree of deviation between the actual geometric parameters (geometric size, geometric shape and mutual position) and the ideal geometric parameters of a part after processing. The degree of conformity between the actual geometric parameters and the ideal geometric parameters after part machining is the machining accuracy. The smaller the machining error and the higher the degree of conformity, the higher the machining accuracy. Machining accuracy and machining error are two ways to address the same problem. Therefore, the size of processing error reflects the level of processing accuracy. 1、 Manufacturing error of machine tool The manufacturing errors of machine tools mainly include spindle rotation error, guide rail error and transmission chain error. Spindle rotation error refers to the variation of the actual rotation axis of the spindle relative to its average rotation axis at each instant, which will directly affect the precision of the workpiece to be processed. The main reasons for the spindle rotation error are the coaxiality error of the spindle, the error of the bearing itself, the coaxiality error between bearings, and the spindle winding. The guide rail is the benchmark for determining the relative position of each machine tool component on the machine tool, and also the benchmark for machine tool movement. The manufacturing error of the guide rail itself, uneven wear of the guide rail and installation quality are important factors causing the guide rail error. Transmission chain error refers to the relative motion error between transmission elements at both ends of the transmission chain. It is caused by the manufacturing and assembly errors of each component of the transmission chain, as well as the wear in the use process. 2、 Geometric error of tool Any tool in the cutting process will inevitably produce wear, which will cause changes in the size and shape of the workpiece. The influence of geometric errors of cutting tools on machining errors varies with the types of cutting tools: the manufacturing errors of cutting tools will directly affect the machining accuracy of workpieces when using fixed size cutting tools; For general tools (such as turning tools), their manufacturing errors have no direct impact on machining errors. 3、 Geometric error of fixture The function of the fixture is to make the workpiece have the correct position equivalent to the cutter and machine tool, so the geometric error of the fixture has a great influence on the machining error (especially the position error). 4、 Positioning error Positioning error mainly includes datum misalignment error and positioning pair manufacturing inaccuracy error. When machining the workpiece on the machine tool, a number of geometric elements on the workpiece must be selected as the positioning datum during processing. If the selected positioning datum does not coincide with the design datum (the datum used to determine the size and position of a surface on the part drawing), the datum misalignment error will occur. The workpiece locating surface and the fixture locating element together constitute the locating pair. The maximum position variation of the workpiece caused by the inaccuracy of the manufacturing of the locating pair and the fit clearance between the locating pairs is called the manufacturing inaccuracy error of the locating pair. The manufacturing inaccuracy error of the positioning pair will only occur when the adjustment method is used for processing, and will not occur when the trial cutting method is used for processing. 5、 Error caused by force deformation of process system Workpiece stiffness: In the process system, if the workpiece stiffness is relatively low compared with the machine tool, tool and fixture, under the action of cutting force, the deformation of the workpiece due to insufficient stiffness will have a greater impact on the machining error. Tool stiffness: the external turning tool has a large stiffness in the normal (y) direction of the machining surface, and its deformation can be ignored. For boring the inner hole with smaller diameter, the rigidity of the cutter bar is very poor, and the force deformation of the cutter bar has a great impact on the hole processing accuracy. Stiffness of machine tool components: machine tool components are composed of many parts. Up to now, there is no suitable simple calculation method for the stiffness of machine tool components. At present, the stiffness of machine tool components is mainly measured by experiment. The factors that affect the rigidity of machine tool components include the influence of contact deformation of joint surface, friction force, low rigidity parts and clearance. 6、 Error caused by thermal deformation of process system The thermal deformation of the process system has a great influence on the machining error, especially in precision machining and large workpiece machining. The machining error caused by thermal deformation sometimes accounts for 50% of the total error of the workpiece. 7、 Adjustment error In each process of machining, the process system must be adjusted in one way or another. Because the adjustment cannot be absolutely accurate, adjustment errors are generated. In the process system, the mutual position accuracy of workpiece and cutter on the machine tool is guaranteed by adjusting the machine tool, cutter, fixture or workpiece. When the original accuracy of the machine tool, cutter, fixture and workpiece blank meet the process requirements without considering dynamic factors, the adjustment error plays a decisive role in the machining error. 8、 Measurement error When parts are measured during or after processing, the measurement accuracy is directly affected by measurement methods, measuring tool accuracy, workpiece and subjective and objective factors. 9、 Internal stress Internal stress refers to the stress that exists inside the part without the action of external force. Once the internal stress is generated on the workpiece, the workpiece metal will be in an unstable state of high energy level. It will instinctively transform to a stable state of low energy level, accompanied by deformation, so that the workpiece will lose its original processing accuracy.

Many 3D printed metal parts need to be machined to generate precise surfaces. However, 3D printed parts are often lightweight parts with complex geometric shapes, which brings challenges to subsequent machining. When machining 3D printing parts, it is necessary to consider whether the stiffness of 3D printing meets the requirements of machining, how to clamp these 3D printing parts with complex structures, and a series of problems. We discussed the challenges and solutions in the machining of 3D printed metal parts through a case shared by additive manufacturing experts. 3D printing is a flexible technology with few constraints on design. With the help of 3D printing technology, designers can realize some complex design schemes, such as lightweight structures and integrated structures with integrated functions. However, these advantages of additive manufacturing technology are sometimes weakened by taking into account the challenges arising from subsequent machining. If the challenges faced in subsequent machining are not fully taken into account in the initial design and manufacturing of additive manufacturing parts, losses may occur due to part processing failure. 3D printed parts usually need to be machined to achieve accurate round holes and smooth and flat surfaces, and then assembled with other parts. However, the complex lightweight structure of 3D printing parts sometimes cannot adapt to the processing process due to insufficient stiffness. In addition, the complex structure also increases the difficulty of safely clamping the workpiece. Challenges of finishing 1. Is the rigidity of 3D printed parts sufficient to meet the load borne during machining? Does the part deviate from the tool and generate vibration, which makes the tool vibrate and leads to poor machining effect? If the stiffness of 3D printing parts is not enough to meet the requirements of machining, what solutions can be used to solve these problems? 2. If the problem of stiffness is solved, the next challenge is how to align the machine tool. 3D printed parts may have some deformation during printing, and lack of clear datum, which means that when machining 3D printed parts, it is necessary to first find the "good" part of the parts. It is very important to obtain the optimal 5-axis alignment of the part. Renishaw explored the challenges and solutions faced in the finishing of 3D printed parts through a metal 3D printed microwave guide rod. From the preparation before machining to the final finishing of parts, there are a total of 9 steps. The left figure shows the guide rod manufactured with traditional design ideas and manufacturing methods, which is assembled from several parts; The right figure shows the 3D printed guide rod, which is an integrated part. Compared with the original part, its weight is reduced by half. This is a part designed for telecommunications satellites. The main performance requirements for this part are lightweight, improving microwave transmission efficiency, and reducing the space requirements of this part for satellite payloads. Solution Step 1: Establish the desired cutting force First, evaluate whether 3D printing parts have enough stiffness required by machining through experiments. Dynamo Data shows the repeated load, and it can be seen that the peak force is about twice the middle value. You can also try cutting at different depths to see how it affects the load on the part. Step 2: Simulate cutting force Through the simulation process, it is found that the flange edge processing around the free end of the part causes obvious deflection (greater than 150 μ m), and the finite element analysis also shows obvious distortion, which may lead to uneven cutting. Step 3: Initial cutting test If machining is carried out under the above conditions, the parts will deviate from the tool and rebound, resulting in surface vibration, tool vibration and other problems. The result of these problems is poor surface finish. The way to solve these problems is to improve the rigidity of the parts in the cutting process. There are two steps to improve the stiffness, one is to adjust the design of 3D printing parts, and the other is to change the clamping mode during machining. First, let's understand how to solve these problems by adjusting the design. Step 4: Meet the challenge of machining by changing the design of 3D printing parts The goal of changing the design of 3D printed parts is to make the parts more rigid. In this case, the designer added a support structure connecting the components at both ends of the parts to reduce the defects seen in the cutting test. Or add a connected truss structure between two end components, which is more complex. The disadvantage of improving the stiffness by adjusting the design scheme is that it increases the volume occupied by the parts, which may affect the space occupied by other components and reduce the overall efficiency of the design. Another noteworthy problem is that in the conventional workpiece clamping mode, the parts after adjustment and design are often still unable to meet the machining requirements, so it is necessary to reconsider the clamping mode of the parts. Step 5: Reconsider the clamping method of parts In this case, the specific solution of the re clamping method is to design a customized fixture for the 3D printing part, and directly manufacture the customized fixture with the 3D printing equipment, reducing the risk of part deformation and surface damage, making the 3D printing part closer to the processing features, reducing deflection and vibration. Step 6: Modeling customized fixture During the finite element analysis of 3D printed parts in the fixture, the designer found that the stiffness could be further improved by better clamping the "straight" structure in the part. Step 7: Machining preparation After completing the design adjustment of 3D printing parts and the design and manufacture of customized fixtures, we can enter the preparation stage of machining. The figure shows the topology optimized 3D printing part measured on the flexible gauge to generate 5-axis alignment for subsequent processing. In this process, errors occur when the linear and rotational motion of the mechanical shaft exceeds the tolerances required to manufacture accurate parts. In this case, the engineer used Renishaw contact probe and metering software NC Checker to identify and monitor these problems. Step 8: Part setup In conventional machining, datum planes are often created first, and then these features are used to align and position parts for subsequent machining operations. However, for the 3D printing part in this case, the conventional method was not followed, because the precision datum must be added to the final machining operation after generating all other surfaces. The challenge of 3D printing part setting is to set it according to the actual shape of the part, which involves understanding the material condition of the part in all areas where precision features are planned to be cut, taking into account the machining allowance, part deformation and other factors. In this case, the designer seeks to leave enough material at all these locations to allow consistent and efficient cutting. In this step, the probe and metering software can still be used to find the "best fit" setting of the finishing. Another way to set up a 3D printed part for finishing is to use shop programmable specifications to measure the part and perform alignment. This method is more suitable for larger batch applications. Step 9: Machining Through the preparation of the above 8 steps, the obtained components have critical dimensions within the tolerance range and show good surface finish. Compared with the early cutting tests, the tool vibration and wear are greatly reduced. Machining is usually a part of the metal 3D printing process chain, which is also a process with flight and risk. If the machining fails, a valuable 3D printing part will be scrapped. If the challenges faced in machining can be considered at the beginning of designing 3D printed parts, it will help reduce the risk of failure.

1、 Information from scrap Scrap is essentially the reverse image of the formed hole. That is, the same part in opposite position. By checking the scrap, you can judge whether the clearance between the upper and lower dies is correct. If the gap is too large, the waste will have a rough, undulating fracture surface and a narrow bright zone area. The larger the gap, the greater the angle between the fracture surface and the bright zone area. If the gap is too small, the waste will show a small angle fracture surface and a wide bright zone area. Excessive clearance forms holes with large crimping and edge tearing, which makes the profile slightly have a thin edge protruding. Too small a gap forms a band that is slightly curled and torn at a large angle, causing the profile to be more or less perpendicular to the material surface. An ideal waste material should have reasonable collapse angle and uniform bright zone. In this way, the minimum punching force can be maintained and a clean round hole with few burrs can be formed. From this point of view, extending the die life by increasing the gap is at the expense of the quality of finished holes. 2、 Selection of die clearance The clearance of the die is related to the type and thickness of the material being punched. Unreasonable clearances can cause the following problems: (1) If the clearance is too large, the burr of the stamping workpiece is relatively large, and the stamping quality is poor. If the clearance is too small, although the punching quality is good, the wear of the die is relatively serious, which greatly reduces the service life of the die and is easy to cause the break of the punch. (2) Too large or too small clearance is easy to produce adhesion on the punch material, thus causing the material to be carried during stamping. If the clearance is too small, it is easy to form a vacuum between the bottom of the punch and the sheet metal, which will cause the scrap to rebound. (3) Reasonable clearance can extend the life of the die, discharge effectively, reduce burr and flanging, keep the plate clean, keep the hole diameter consistent and will not scratch the plate, reduce the number of grinding, keep the plate straight, and punch the hole accurately. Please refer to the following table to select the die clearance (the data in the table is a percentage) 26e90001fd75ee9cec5d 3、 How to improve the service life of dies For users, improving the service life of the die can greatly reduce the stamping cost. The factors affecting the service life of the mold are as follows: 1. Type and thickness of materials; 2. Whether reasonable lower die clearance is selected; 3. The structure of the mold; 4. Whether the materials are well lubricated during stamping; 5. Whether the mold has undergone special surface treatment; 6. Such as titanium plating, carbon titanium nitride; 7. Neutrality of upper and lower turrets; 8. Reasonable use of adjusting shims; 9. Whether the die with inclined cutting edge is properly used; 10. Whether the mold base of the machine tool has been worn; 4、 Problems needing attention in punching holes with special dimensions (1) Minimum hole diameter: punch φ 0.8—— φ 1.6 Special punch shall be used for punching within the range. (2) When punching thick plates, please use a larger die relative to the processing hole diameter. Note: At this time, if the normal size die is used, the punch thread will be damaged. Example 1. For the processing conditions in the following table, although the processing hole diameter corresponds to the mold at station A, please use the mold at station B. Example 2. For the processing conditions in the following table, although the processing hole diameter corresponds to the die at station B, please use the die at station C. (3) The ratio of the minimum width to the length of the punch cutting edge should generally not be less than 1:10. Example 3: When the cutting edge length of rectangular punch is 80mm, the cutting edge width ≥ 8mm is the most appropriate. (4) The relationship between the minimum size of the punch cutting edge and the plate thickness. It is recommended that the minimum size of the cutting edge of the punch should be 2 times of the plate thickness. Extended reading: 1. [Process control] All you want about stamping dies are here (II) 2. [Process control] All you want about stamping dies are here (III) 3. [Process control] All you want about stamping dies are here (IV)

Grinding of die 1. The Importance of Die Grinding Regular sharpening of the die is the guarantee of consistent punching quality. Regular grinding of the die can not only improve the service life of the die but also increase the service life of the machine. It is necessary to grasp the correct grinding time. 2. Specific features of the die requiring grinding For die grinding, there is no strict strike number to determine whether grinding is required. It mainly depends on the sharpness of the cutting edge. It is mainly determined by the following three factors: (1) Check the fillet of the cutting edge. If the fillet radius reaches R0.1mm (the maximum R value shall not exceed 0.25mm), it needs to be sharpened. (2) Check the punching quality. Is there any big burr? (3) Judge whether grinding is required by the noise of machine punching. If the noise of the same die is abnormal during stamping, it indicates that the punch is blunt and needs to be sharpened. Note: If the edge of the cutting edge becomes rounded or the back of the cutting edge is rough, grinding should also be considered. 3. Grinding method There are many methods for die grinding, which can be realized by using a special grinding machine or a surface grinder. The frequency of punch and lower die grinding is generally 4:1. Please adjust the die height after grinding. (1) Harm of incorrect grinding method: incorrect grinding will aggravate the rapid damage of the die edge, resulting in a greatly reduced number of blows per grinding. (2) Benefits of correct grinding method: regularly grind the die, and the quality and accuracy of punching can be kept stable. The cutting edge of the die is damaged slowly and has a longer service life. 4. Grinding rules The following factors shall be considered when grinding the die: (1) The sharpness of the cutting edge shall be considered when the fillet of the cutting edge is R0.1-0.25mm. (2) The surface of the grinding wheel shall be cleaned. (3) A loose, coarse grain, soft grinding wheel is recommended. E.g. WA46KV (4) Each grinding amount (cutting amount) shall not exceed 0.013mm. Excessive grinding amount will cause overheating of the mold surface, which is equivalent to annealing treatment, and the mold will become soft, greatly reducing the life of the mold. (5) Sufficient coolant must be added during grinding. (6) During grinding, the punch and lower die shall be fixed stably, and special tooling fixtures shall be used. (7) The grinding amount of the die is certain. If it reaches this value, the punch will be scrapped. If it is used continuously, it is easy to cause damage to the mold and the machine, and the gain is not worth the loss. (8) After grinding, the edges shall be treated with an oilstone to remove excessively sharp edges. (9) After grinding, the blade shall be cleaned, demagnetized and oiled. Note: The grinding amount of the die mainly depends on the thickness of the punched sheet. Attention shall be paid to the punch before use 1. Storage (1) Clean the inside and outside of the upper mold sleeve with a clean rag. (2) Be careful not to scratch or dent the surface when storing. (3) Apply oil to prevent rust. 2. Preparation before use (1) Clean the upper die sleeve thoroughly before use. (2) Check the surface for scratches and dents. If any, remove it with an oilstone. (3) Oil inside and outside. 3. Precautions for installing the punch on the upper die sleeve (1) Clean the punch and oil its long handle. (2) Insert the punch into the bottom of the upper die sleeve on the large station die without force. Do not use nylon hammers. During installation, the punch cannot be fixed by tightening the bolts on the upper die sleeve. The bolts can only be tightened after the punch is correctly positioned. 4. Install the upper formwork assembly into the turret If you want to extend the service life of the mold, the clearance between the outer diameter of the upper mold sleeve and the turret hole should be as small as possible. So please execute the following procedure carefully. (1) Clean and oil the keyway and inner diameter of the turret hole. (2) Adjust the keyway of the upper die guide sleeve to fit the key of the turret hole. (3) Insert the upper die sleeve into the tower hole straightly and carefully without any inclination. The upper die guide sleeve should slide into the turret hole by its own weight. (4) If the upper mold sleeve is inclined to one side, gently knock it with soft material tools such as nylon hammer. Repeat the tapping until the upper die guide sleeve slides into the correct position with its own weight. Note: Do not force on the outer diameter of the upper die guide sleeve, only on the top of the punch. Do not knock the top of the upper die sleeve to avoid damaging the turret hole and shortening the service life of individual stations.  Maintenance of moulds If the punch is stuck by the material and cannot be taken out, please check according to the following items. 1. Re sharpening of punch and lower die. The die with sharp edge can process beautiful cutting section. If the edge is blunt, additional punching force is required. Moreover, the workpiece section is rough, resulting in great resistance, causing the punch to be bitten by the material. 2. Die clearance. If the clearance of the die is not suitable for the thickness of the plate, the punch needs a large demoulding force when it is separated from the material. If the punch is bitten by the material for this reason, please replace the lower die with a reasonable clearance. 3. Status of processing materials. When the material is dirty or there is dirt, the dirt will attach to the mold, making the punch bit by the material and unable to process. 4. Material with deformation. After punching the hole, the warped material will clamp the punch so that the punch is bitten. For materials with warpage, please smooth them before processing. 5. Excessive use of springs. It will fatigue the spring. Please always check the performance of the spring. 8、 Oiling The amount of oil and the number of oil injections depend on the conditions of the material being processed. For cold rolled steel plate, corrosion resistant steel plate and other rust free and scale free materials, oil shall be injected into the mold. The oil injection points are the guide sleeve, the oil injection port, the contact surface between the tool body and the guide sleeve, and the lower mold. Light engine oil for oil. For materials with rust and scale, rust powder will be sucked into the space between the punch and the guide sleeve during processing, resulting in dirt, which will prevent the punch from sliding freely in the guide sleeve. In this case, if oil is applied, the rust will be more easily stained. Therefore, instead of cleaning the oil when flushing this material, it should be disassembled once a month, and the dirt on the punch and the lower mold should be removed with gasoline (diesel) oil, and then cleaned before reassembly. In this way, good lubrication performance of the die can be guaranteed.

Machining of mechanical parts is the process of changing the external dimensions or performance of a part by a mechanical device. So do you know what are the specific processing methods of mechanical parts? Let me share with you today!   The main mechanical processing methods are: turning, clamping, milling, planing, inserting, grinding, drilling, boring, punching, sawing and other methods. Can also include wire cutting, casting, forging, electro-etching, powder processing, electroplating, various heat treatment, etc.   Turning: there are vertical and horizontal turning; new equipment has CNC turning, mainly processing rotary body;   Milling: vertical milling, horizontal milling; new equipment has CNC milling, also called machining center; mainly processing groove and profile straight surface, of course, can also be two-axis or three-axis linkage processing arc surface;   Planing: mainly processing profile straight surface, under normal circumstances, the surface roughness is not as high as the milling machine; Insert: can be interpreted as a stand-up planer, ideal for non-complete arc processing; Grinding: surface grinding, external grinding, internal hole grinding, tool grinding, etc.; processing of high precision surface, the surface roughness of the processed workpiece is particularly high;   Drilling: the processing of holes;   Boring: the processing of larger diameter, higher precision holes, the processing of larger workpiece shape. There are also many processing methods for holes, such as CNC machining, wire cutting, etc.   Punching: mainly by punching machine punching, can punch round or shaped holes;   Sawing: mainly through the sawing machine cutting processing, commonly used in the undercutting process.