China Shenzhen Perfect Precision Product Co., Ltd. company news

Precision mechanical parts is about precision, in the actual production process we must ensure that the degree of precision to meet the relevant standards, and as far as possible to improve. At present, how to improve the precision of precision mechanical parts has become a key issue for the relevant enterprises. In the process of deburring, polishing in the problem will directly affect the accuracy of the parts, but also the current production automation is difficult to solve the problem. Today I want to explain is how to check the precision mechanical parts processing?   First, the basic requirements of the inspector. 1, to have more professional knowledge and practical work experience, but also need to meet the requirements of the first product on the inspection work. 2, the measuring instruments used need to be calibrated by the metrology department and in the specified calibration cycle. 3, in the acceptance of products before the need to familiarize themselves with the relevant drawings and technical documents, to understand the key dimensions of the parts and the key points of the assembly relationship. 4、To strictly follow the requirements of the drawings and technical documents to determine the parts. 5、For the workshop in-process products in accordance with the provisions of the logo.   Second, the inspection system. 1, the first inspection system: for each operator processing the first part, need to carry out a full range of inspection and do a good job on the stay. 2, inspection system: to ensure that the key parts will be able to get the whole controlled state. 3、Transfer inspection system: for the parts that will be transferred to the next process, inspection should be carried out to avoid unqualified products into the next process. 4, the completion of the inspection system: for the completion of the production of products to be warehoused for completion of inspection, including size and shape, whether there is a missed processing process and so on. Three, inspection methods. 1、Basic size and shape inspection a. Measurement of outer diameter For the outer diameter measurement, need to measure in the circumferential two parts, and record. When the length of the same diameter of the part is greater than 50 mm, should be straightness inspection, the use of knife edge ruler work surface contact with the outer diameter bus, observe the width of the building, and then against the standard light gap to make a judgment. b. Measurement of the inner diameter When measuring the size of the inner diameter of the part, just measure in three parts of the circumference, while making records. When the same diameter length is greater than 40mm, should be made cylindricity check, in the same diameter length direction range, respectively, to obtain a larger interval two positions for measurement. Calculate the cylindricity error. c. Length measurement External thread measurement: The middle diameter of external thread is measured by thread ring gauge or three pins, and the small diameter is detected by thread ring gauge (through gauge). Internal thread measurement: The outer diameter of internal thread is inspected with a thread plug gauge (through gauge), and the middle diameter is inspected with a thread plug gauge. The large, medium and small diameters of the threads should be inspected according to the accuracy level required by the drawing. The effective length tolerance of the thread: according to the requirements of HY/QT001 Fastener Inspection Specification.   2. Inspection of surface plane a. Surface roughness inspection: use the sample block comparison method for comparative judgment. b. Flatness inspection: the use of playing table method of detection, the flat plate placed on three adjustable support, the part measuring surface placed on the support points facing upward, adjust the support points, so that the three points are equal, the peak and valley value measured by playing table is the flatness of the plane error.

Machining error of mechanical parts is the degree of deviation between the actual geometric parameters (geometry, geometry and mutual position) of the part after machining and the ideal geometric parameters, the smaller the machining error, the higher the degree of conformity, the higher the machining accuracy. Machining accuracy and machining error are two ways of saying the same thing.   Mechanical parts processing errors that are likely to occur. 1, positioning error: positioning error mainly includes the benchmark does not overlap error and positioning vice manufacturing inaccuracy error. 2, measurement error: parts in processing or measurement after processing, due to the measurement method, gauge accuracy and workpiece and subjective and objective factors directly affect the measurement accuracy. 3, tool error: any tool in the cutting process is inevitable to produce wear and tear, and thus cause the size and shape of the workpiece to change. 4, fixture error: the role of the fixture is to make the workpiece equivalent to the tool and machine tool has the correct position, so the geometric error of the fixture on the machining error (especially the position error) has a great impact 5, the machine tool error: including spindle rotation error, guide error and drive chain error. Spindle rotation error refers to the actual axis of rotation of the spindle moment relative to its average axis of rotation of the amount of change, it will directly affect the accuracy of the workpiece being machined.

Precision parts processing and manufacturing is to process high precision mechanical parts as the object. Using systematic and integrated theory and technology, the organic combination and optimization of material supply, processing, testing and handling are realized according to the structure and requirements of the processed workpiece, how to diagnose the failure of the lathe in mechanical parts processing? Mechanical parts processing lathe maintenance personnel to master the principle of first external and then internal, that is, when mechanical failure occurs, maintenance personnel should use the method of looking, smelling, listening, asking, etc., from the outside to the inside to check one by one. First, first static then move. Maintenance personnel to achieve first static after the action, not blindly hands, should first ask the mechanical parts processing operators the process of failure and the state, check the manual, information before the hands to find the cause of the failure, and then troubleshooting. Second, first simple and then complex. Hardware processing plant machine tools with a variety of faults intertwined cover, a moment to start, should first solve the easy problem, after solving the larger problem. Often in the process of solving simple faults, the difficulty of the problem may become easier, clear your mind, the more difficult become easier. Third, first mechanical and then electrical. As mechanical parts lathe processing is a high degree of automation, advanced mechanical processing equipment with complex technology. Mechanical faults are easier to find, while system fault diagnosis is more difficult. Fourth, first communal and then special. The communal problem will affect the whole situation, while the special problem only affects the local. Five, first general and then special. When troubleshooting a fault, consider the most common possible causes first, and then analyze the special causes that rarely occur.

The main methods of machining mechanical parts are.   Turning, 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: there are 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: mainly by boring tool or insert boring bore; Punching: mainly by punching machine, can punch round or shaped holes; Sawing: mainly through the sawing machine cutting processing, commonly used in the process of undercutting.

Do a good job of machine maintenance in order to make the machine processing accuracy to maintain the best state, to extend the use of machine life, that precision mechanical parts processing equipment should be how to maintain it? After the machine is started, it is prohibited to maintain the machine. Maintenance process, the circuit breaker should be disconnected.   Machining precision maintenance. 1, after the machine is turned on, it must be warmed up for about 10 minutes before processing. Machines not used for a long time should extend the preheating time. 2、Check whether the oil circuit is smooth 3, before shutting down the machine will be the table, saddle placed in the central position of the machine (move the three axis travel to the middle of each axis travel). 4、Keep the machine dry and clean. Caution: After the machine is started, maintenance of the machine is prohibited. During maintenance, the circuit breaker should be disconnected. First, daily maintenance (do professional CNC machining master must do) 1, check the height of the lubricant level to ensure that the machine tool lubrication. It is recommended to use T68 # guide oil. 2, check whether the coolant tank coolant is sufficient, not enough to add in time. 3, check the height of the pneumatic triplex oil level, about 2/3 of the entire oil tube height can be. Every day the pneumatic triplex oil filter tank water gas by the drainage switch to discharge. 4、Check the air pressure, relax the adjusting knob, adjust the pressure according to the principle of right rotation to increase pressure and left rotation to decrease pressure, generally set to 5-7KG/CM2. 5KG/CM2 is usually set by the pressure switch, and the alarm will appear when it is lower than 5KG/CM2. When the pressure rises, the alarm message disappears. 5、Check whether the air blowing in the spindle inner taper hole is normal, wipe the spindle inner taper hole with clean cotton cloth and spray light oil. 6、Clean the tool magazine tool arm and tool, especially the tool claw. 7、Clean the exposed limit switch and the touch block. 8、Clean the cutting and oil stains on the table, inside the machine tool and the three axes telescopic guard. 9、Check all signal lights and warning lights of different alarms are normal. 10, check whether the oil pressure unit tube leakage. 11, the machine tool daily work after the completion of cleaning and cleaning work. 12, maintain the machine around the environment neat and tidy.   Second, weekly maintenance 1、Clean the air filter of the heat exchanger, cooling pump, lube oil pump filter. 2、Check whether the tool pull bolt is loose and the tool handle is clean. 3、Check whether the three-axis mechanical origin is offset. 4、Check whether the tool changer arm action or tool changer tool rotation is smooth. 5、If there is oil cooler, check the oil cooler oil, if it is lower than the scale line, please refill the oil cooler oil in time. Recommend to use 10# spindle oil. 6、Check the setting temperature of oil cooler, it is recommended to set it between 26-28 degrees.   Third、Monthly maintenance 1、Check the lubrication of X, Y and Z axes track, the track surface must be well lubricated. 2、Check and clean the limit switch and touch block. 3、Check whether the oil cup oil of the beater cylinder is enough, and add it in time. 4、Check whether the indication plate and warning nameplate on the machine are clear and exist. Four, half-year maintenance 1、Disassemble the three axes chip guard, clean the three axes oil pipe joint, ball lead screw, three axes limit switch, and test whether it is normal. Check whether the effect of hard rail scraping brush piece of each axis is good. 2、Check whether the servo motor and head of each axis are running normally and there is no abnormal sound. 3、Replace the oil pressure unit oil and tool reducer mechanism oil. 4、Test the clearance of each axis, if necessary, adjust the compensation amount. 5、Clean the dust in the electric box (make sure the machine tool is in the off state). 6、Completely check whether the contacts, joints, sockets and switches are normal. 7, check and adjust the mechanical level.   V. Annual maintenance 1, check all the keys are sensitive and normal. 2、Clean the cutting water tank and replace the cutting fluid. 3、Check the vertical accuracy of each axis and decide whether it needs to be adjusted.   Six, routine maintenance and repair Note: The maintenance and repair of the equipment should be carried out by professional engineers. 1、 Grounding protection system should have intact continuity to ensure personal safety. 2、 Periodic inspection of circuit breakers, contactors, single-phase or three-phase interrupters and other components. Such as whether the wiring is loose, whether the noise is too loud, find out the cause and eliminate hidden problems. 3、 Ensure the normal operation of the radiator fan in the electric cabinet, otherwise it may lead to damage of the elementary parts. 4、Fuse blows, air switch trips frequently, find out the cause and eliminate it in time. 5、Servo drive battery replacement Absolute system data rely on the servo drive battery to maintain, when the battery voltage is too low (warning 9F), the drive battery needs to be replaced, please order the same type of battery unit as soon as possible, and keep the drive power on. Please turn on the power of the drive unit 30 minutes before replacing the battery, and finish replacing the battery within 1 hour.   Seven, the battery replacement steps 1、Confirm that the input power has been cut off and the power of the drive unit being replaced is OFF. 2, pull out the battery plug connected to the battery socket of the drive unit. 3, press the side of the battery with your fingertips, push the battery horizontally and then remove. 4、The plug of the new battery is connected to the battery socket of the drive unit. 5、Install the battery into the drive unit.

With the development of science and technology, machining equipment is gradually moving towards numerical control. CNC finishing has become the processing technology of more and more enterprises. Although CNC machining centers have certain skill requirements for operators, CNC machining centers are welcomed by the majority of machining enterprises because of their advantages of high precision, high quality and high efficiency. In this paper, we will specifically introduce the problems encountered in the use of CNC finishing centers and solutions. Troubleshooting of CNC finishing: 1. Sudden loss of parameters In the process of using the horizontal machining center, 930AL and CRT display bar garbled codes appear. After the machine is restarted, the parameters are lost. The machine tool can operate normally when the input parameters are in the startup state. The sudden loss of parameters is generally related to the memory board, battery or external interference. The appearance of 930AL also indicates that there may be external interference, causing the CPU to work abnormally, so a system alarm occurs. However, it does not rule out motherboard or other PCB failures. 2. 926 alarm 926 alarm occurs when using the CNC machining center, and there is no display on the LCD of the control system except for the alarm information. The 926 alarm (FSSB alarm) is caused by the failure of FSSB (servo serial bus) connecting CNC and servo amplifier. If the FSSB, optical cable and servo amplifier connected to the axis control card have problems, this alarm will occur, and the LED on the servo amplifier can confirm the fault location. If the power supply of the servo amplifier fails, FSSB alarm will occur. This is mainly due to the FSSB alarm caused by the voltage drop of the control power supply of the amplifier fault device or the+5V grounding of the encoder cable. 3. Alarm The lathe often gives 920, 911 and 930 alarms, among which 930 alarms are the most frequent. ·With the appearance of 911, parity errors occurred in some program memory RAM. The RAM needs to be fully cleared, or the SRAM module or motherboard needs to be replaced, and then the parameters and data can be reset to improve. ·920 is a servo alarm (first to fourth axes), a monitoring alarm or a RAM parity error in the servo module. It can be improved by replacing the servo control module on the motherboard. ·930 is an abnormal alarm interruption. It is mainly caused by the bad motherboard or CPU card. The faulty parts can be confirmed by exchanging parts. In addition, attention should be paid to machine tool grounding, external interference, etc.

The processing process rules of vertical CNC machining centers are respectively reflected in three aspects: preparation before startup, startup processing, content and scope of workers' self inspection. In addition, the article summarizes the causes of errors, special attention, and corrective measures in a list for reference······  Preparation before startup: 1. Each time the machine tool is started or reset by pressing the emergency stop, first return to the reference zero position of the machine tool (that is, return to zero), so that the machine tool has a reference position for its subsequent operations. 2. Clamping workpiece: 3. Before clamping the workpiece, all surfaces shall be cleaned without oil stain, scrap iron and dust, and burrs on the workpiece surface shall be removed with a file (or oilstone). 4. The equal speed rail used for clamping must be ground smooth and flat by the grinder. The sizing iron and nut must be firm and can reliably clamp the workpiece. For some small workpieces that are difficult to be clamped, they can be directly clamped on the vise. 5. The machine tool workbench shall be clean and free of iron filings, dust and oil stains. 6. The sizing block is generally placed at the four corners of the workpiece. For workpieces with excessive span, an equal height sizing block must be placed in the middle. 7. Use a ruler to check whether the length, width and height of the workpiece are qualified according to the size of the drawing. 8. When clamping the workpiece, according to the clamping and placement method in the programming operation instructions, it is necessary to consider avoiding the processing parts and the situation that the cutter head may encounter the fixture during processing. 9. After the workpiece is placed on the sizing block, the datum plane of the workpiece shall be pulled according to the drawing requirements. The error in the length direction of the workpiece is less than 0.02mm, and the horizontal error in the X and Y directions of the top surface is less than 0.05mm. For workpieces that have been ground on six sides, check whether their verticality is qualified. 10. After the workpiece is pulled, the nut must be tightened to prevent the workpiece from shifting during processing due to insecure clamping. 11. Pull the meter again to ensure that the error does not exceed the tolerance after clamping. 12. Number of workpiece collisions: for the clamped workpiece, the number of collision heads can be used to determine the reference zero position for processing. The number of collision heads can be photoelectric or mechanical. The method of collision selection can be divided into two types: middle collision number and single collision number, The mechanical speed is 450-600rpm. 13. Carefully record the mechanical coordinate value of the zero position on the X axis of the workpiece in one of G54~G59, and let the machine tool determine the zero position on the X axis of the workpiece. Check the correctness of the data again. 14. Prepare all tools according to the programming instructions. 15. According to the tool data in the programming operation instruction, replace the tool to be processed and let the tool touch the height measuring device on the reference plane. When the red light of the measuring device is on, set the relative coordinate value of this point to zero. 16. Move the tool to a safe place, manually move the tool down 50mm, and set the relative coordinate value of this point to zero again, which is the zero position of Z-axis. 17. Record the mechanical coordinate Z value of this point in one of G54~G59. This completes the zero setting of X, Y, Z axes of the workpiece. Check the correctness of the data again. 18. Check the correctness of the zero point, move the X and Y axes to the edge of the workpiece, and visually check the correctness of the zero point according to the size of the workpiece. Start up processing: 1. At the beginning of each program, carefully check whether the tool used is the tool specified in the programming instruction. At the beginning of processing, the feed speed shall be adjusted to the minimum, and the single section operation shall be performed. The quick positioning, tool dropping and tool feeding shall be carried out with concentration. If there is a problem with the hand on the stop key, stop immediately. Pay attention to the direction of the tool movement to ensure safe tool feeding, and then slowly increase the feed speed to the appropriate level. At the same time, add coolant or cold air to the tool and workpiece. 2. The rough machining shall not be too far away from the control panel, and the machine shall be shut down for inspection in case of any abnormality. 3. Pull the meter again after roughening to ensure that the workpiece is not loose. If there is a side, it must be corrected and touched again. 4. Continuously optimize the processing parameters during the processing to achieve the best processing effect. 5. Since this process is a key process, after the workpiece is processed, measure whether its main dimension values are consistent with the drawing requirements. If there are problems, immediately notify the shift leader or programmer to check and solve them. After the self inspection is qualified, it can be removed, and must be sent to the inspector for special inspection. 6. Clean the machine tool workbench in time after the workpiece is removed. 7. Direct numerical control (DNC) operation: 8. Before DNC numerical control processing, the workpiece shall be clamped, the zero position shall be set, and the parameters shall be set. 9. Open the processing program to be transferred in the computer to check, then let the computer enter the DNC state, and input the file name of the correct processing program. 10. Press TAPE key and program start key on the processing machine tool, and the machine controller will flash LSK. 11. Press the Enter key on the computer to conduct DNC data transmission processing. 3、 Self inspection content and scope of workers: 1. Before processing, the processor must see the contents of the process card clearly, know the part, shape, drawing dimensions of the workpiece to be processed, and know the processing content of the next process. 2. Before clamping the workpiece, measure whether the blank size meets the drawing requirements. When clamping the workpiece, carefully check whether its placement is consistent with the programming operation instructions. 3. After the rough machining is completed, self inspection shall be carried out in time to adjust the data with errors in time. The self inspection mainly covers the position and size of the machining parts. For example: (1) Whether the workpiece is loose; (2) . Whether the workpiece is correctly centered; (3) Whether the dimension from the processing part to the datum edge (datum point) meets the drawing requirements; （4）. The position and size of processing parts. After checking the position and size, measure the rough machined shape ruler (except the arc). 4. Finish machining can only be carried out after rough machining and self inspection. After finishing, the workers shall conduct self inspection on the shape and size of the processing part: detect the basic length and width of the processing part of the vertical surface; Measure the base point size marked on the drawing for the processing part of the inclined plane. 5. After the workers finish the self inspection of the workpiece, they can remove the workpiece and send it to the inspector for special inspection after confirming that it conforms to the drawing and process requirements.

With the aggravation of energy crisis and environmental problems, energy conservation and safety have become the most important starting point of automobile manufacturing industry. In order to achieve the above objectives, reducing vehicle weight is a very effective method, which leads to the rapid development and application of advanced high-strength steel. The use of hot forming technology can greatly improve the stiffness and strength of the overall body structure, and greatly improve the vehicle crash safety and NVH performance; A large number of applications of this technology can effectively reduce the weight of BIW, reduce energy consumption, reduce environmental pollution, and improve the economic performance of the vehicle. At present, according to the requirements of body structure strength, hot forming technology is mainly applied to the production of high-strength components such as front and rear bumpers, A pillars, B pillars, C pillars, roof reinforcement beams, underbody channel frames, dashboard brackets, door inner panels, door crash beams, etc. (see Figure 1). The proportion of hot formed parts in BIW of the whole vehicle can reach more than 45%. At present, hot forming technology has been widely used in automobile manufacturing companies at home and abroad. Major domestic automobile manufacturers have widely used hot formed parts for the production and design of vehicle models. The number of hot formed parts used in a single vehicle has generally reached 6 to 10, and the highest number of vehicle models has reached 24. However, these hot stamping technology and die technology have been monopolized by foreign companies for a long time. The hot forming dies used by most manufacturers are imported and expensive. This time, we cooperated with Wuhan Iron and Steel Research Institute to develop the B pillar hot forming mold and parts for a certain passenger car of Dongfeng Company using Wuhan Iron and Steel WHT1500HF hot forming steel. This paper introduces the development of hot forming die and parts with B pillar as an example. Development of B pillar thermoforming parts The hot forming evaluation material of B column parts is WHT1500 steel with a thickness of 1.80mm. The material mechanical properties are shown in Table 1, the hot forming process test parameters are shown in Table 2, and the mechanical property curve is shown in Figure 1. Analysis of thermoforming process 1. Boundary conditions The single acting die structure is adopted, that is, the female die is on the top, the male die is on the bottom, and the stamping direction is as shown in Figure 3 Boundary condition: the initial temperature of the sheet is 800 ° C, and the sheet transfer time is not more than 3.5s; The waiting time of the sheet on the die before clamping is 3.5s; The clearance between die and blank holder is 1.5 x material thickness; The blank holder pressure is 1T; The forming and clamping speed is 150 mm/s; The holding pressure during quenching is 400t; The initial temperature of the mold is 100 ℃ on the surface and 20 ℃ inside. 1. Boundary conditions Molding analysis The blank of the part is unfolded by Pamstamp to get the sheet, and the forming module is analyzed in Pamstamp. In the forming simulation, the maximum thinned area is located on the side of the lower half area of the neutral column (MAX-23% as shown in the figure), and the thickened area is located on the front of the lower middle area of the central column as shown in the figure (+23.2% as shown in Figure 4). According to this situation, it was decided to pay attention to this area during mold processing and part debugging. 3. Simulation analysis of forming process In the forming module of Pamstamp, observe the forming condition of the sheet metal during the movement of the mold. Figure 5 shows the upper mold is 40mm, 20mm, 5mm away from the lower dead center and the last formed part. At 5mm from the upper mold to the lower dead center, it can be found that there is wrinkling under the middle column. In the debugging phase of the mold, strong pressing will be done here. 4. Temperature field analysis The temperature distribution of the part at the moment of forming when the upper die is at the lower dead point is obtained through the analysis module in the Pamstamp module. In order to obtain the martensite structure at last, the part temperature can be observed to be higher than 665 ℃ through simulation, which conforms to the standard and meets the quenching transformation conditions. 5. Distribution of martensite in quenched parts Carry out analysis, as shown in Fig. 6a, the parts are quenched after 10s in the die, and more than 90% of the parts have been transformed into martensite except for the influence of blank holder position; Because the blank holder will be cut off by laser cutting. Fig. 6b shows the pressure holding (10s) temperature. When the part is completed, the surface temperature is less than 200 ° C, and the temperature at the blank holder is higher, which is consistent with the distribution of martensite. 6. Summary of formability analysis (1) The analysis results show that the B pillar part is produced by WHT1500 hot forming, and the process is feasible. (2) The area at the bottom of the part is the risk area of material wrinkling. It is recommended to increase the pressing force and reduce the die clearance to control the material flow. (3) The fillet at the top of the part is at high risk of cracking. It is recommended to reduce the size of the sheet metal. mould design 1. Design process of hot stamping mold The design process of hot stamping mold is shown in Figure 7. 2. Mold structure design (1) The hot stamping die material shall be H13 hot working die steel. (2) Calculation and layout of cooling water channel ① Calculation formula of cooling channel Where, mw is the mass of water flowing through the mold in unit time (kg/h); N is the number of pipes; Qw is the cooling water flow of a single pipe (m3/h); ρ W is the density of cooling water at a certain temperature (kg/m3), 1000 kg/m3; D is the diameter of cooling water hole (m); V is the flow velocity of cooling water (m/s); Tu is the unit time, 3600s. Where, Re is Reynolds number; V is kinematic viscosity (m2/s), V=1.3077 at 10 ℃ × 10-6m2/s。 ② Cooling channel layout The diameter of cooling pipe is 10-14mm; The center distance between adjacent pipes is 17~20mm; The minimum distance from the pipe center to the profile shall be more than 15mm. The cooling systems of each insert are independent of each other, and the cooling channels between adjacent inserts are not connected with each other. epilogue Through the practice of using domestic hot forming steel to develop hot forming dies and parts for the main engine plant, we have learned and mastered the change rules of hot stamping die technology and heating and cooling organization, and gained some practical experience. During the research and development of the hot forming die for the B pillar of a passenger car, the die structure design of the part was completed through the CAE forming analysis of the part, the simulation of the change of the strength of the part in the temperature field and the check of the die strength. After debugging the hot stamping forming of the die, metallographic analysis and tensile test of the parts, the structure and strength of the parts are ensured to meet the expected requirements. The results show that the application of the designed and manufactured hot forming die for the B pillar of passenger car meets the technical requirements of the product.

1. Use requirements (first consideration) 1) Working conditions of parts (vibration, impact, high temperature, low temperature, high speed and high load should be treated with caution); 2) Limits on part size and quality; 3) Importance of the part. (Relative importance to overall reliability) 2. Process requirements 1) Blank manufacturing (casting, forging, plate cutting, rod cutting); 2) Machining; 3) Heat treatment; 4) Surface treatment. 3. Economic requirements 1) Material price (comparison between blank cost and processing cost of ordinary round steel and cold drawn profile, precision casting and precision forging); 2) Processing batch and processing cost; 3) Utilization rate of materials; (For example, the specifications of plates, bars and profiles should be used reasonably) 4) Substitution (try to use cheap materials to replace relatively expensive rare materials, such as replacing copper sleeves with nodular graphite in some wear-resistant parts, replacing some sleeves machined by turning with oil bearing, and replacing steel gears or copper worm gears with nylon under low speed load). In addition, consider the supply of local materials 1. Basic requirements for mechanical design a) Pay attention to the coordination and balance of the requirements for the machine functions! Prevent the occurrence of cask effect b) Requirements for machine economy The design economy can be put into production and launched in a short period of time to recover the consumption during the development period, or even design and manufacture at the same time The use of economy should have the best performance price ratio (the products start to earn money in small batches, and then they can be improved better) 2. Basic requirements for the design of mechanical parts a) It can work normally and reliably within the scheduled working period to ensure various functions of the machine b) To minimize the production and manufacturing costs of parts c) Use common standard parts in the market as much as possible d) For products that may be serialized, the commonality of parts shall be considered at the beginning of design as much as possible, and those that cannot be used shall be similar in structure as much as possible, so as to reduce the workload of process planning and fixture design in the manufacturing process.

The combination of laser and welding is a breakthrough in traditional industry. It not only improves the welding quality, but also shortens the welding cycle. Nowadays, laser welding processing technology has been applied in many industries, most commonly in high-tech electronics, automobile manufacturing and precision processing fields. However, in the field of automobile manufacturing, the application proportion of laser welding is still in the middle low level. The concept of laser welding is also attributed to Volkswagen. In the dazzling automotive market, Volkswagen has always been favored for its durability. This is exactly what traditional welding processing technology cannot achieve. Many people do not understand the meaning of laser welding. In fact, laser welding is just one of the directions of laser application. It is the use of high-energy laser pulses to instantly heat up and melt the welding points to achieve permanent bonding between metals. This is the latest welding method combined with the traditional process. In view of its advantages such as small weld width, fast welding speed, small influence area, smooth welding, small deformation, and beautiful appearance, laser welding is also used as a variety of welding processes such as spot welding, butt welding, seal welding, and overlay welding. The appearance of laser welding has promoted the large span leap of welding technology and made it possible to weld between metals and nonmetals. Because the production line of laser welding processing technology needs to be completely closed, which itself requires a large amount of capital investment, resulting in its cost far higher than that of traditional welding processing technology. Therefore, in the process of automobile production and manufacturing, laser welding processing technology will be mainly used in the roof and the surrounding parts on both sides. On the one hand, it can save manufacturing costs, and also ensure the beauty and tightness of the automobile. Although Volkswagen was the first brand to introduce laser welding, it is Mercedes Benz, BMW and Ferrari that have played this technology to the extreme. As for the reason, it can be seen from the appearance and sound insulation performance of the car. In recent years, with the laser welding processing technology becoming more and more popular in the market, the competition between laser welding processing plants has become fiercer. How to select laser welding processing plants with quality and quantity guaranteed? There are four standards for reference: strong strength, mature technology, good reputation and excellent after-sales service. Each laser welding processing factory has its own shortcomings. Those factories with high-quality after-sales service may have immature technology; Some factories have strong strength under the banner of the first laser welding processing factory in the industry, but the quality of completion is low. Therefore, if you want to find a good processing plant, you need to consider it comprehensively according to your own needs. Although laser welding processing technology can create a perfect car body and realize seamless welding, most automobile factories still prefer spot welding. The main reason is that for ordinary manufacturers, the cost investment of the former will cause huge economic pressure and will not benefit the health of welding workers. In addition, it needs to be reminded that laser welding processing technology is only useful for shaping the shape of the car, and can not provide substantive protection for the safety performance of the overall body. Consumers should not trust the manufacturer's propaganda about laser welding technology when choosing cars.