Special machine machining center
in order to meet the challenges brought by the rapid development of users in the automotive industry and provide production line equipment with both efficiency and flexibility, cross huler ex-cell-o lamb continues to develop new system structure. The concept of "special machine machining center" launched by cross huler ex-cell-o lamb is a new process to process workpieces in the form of a combination of processing center and special machine
as a machine tool manufacturing company, our task is to constantly seek to adopt new technologies to approach, keep up with or exceed the challenges brought by the rapid changes in the market and investment structure of automotive industry users. In the processing system of auto parts, OEM suppliers and parts suppliers need not only the efficiency of the traditional processing system, but also the flexibility to adapt to the changing market, and the production preparation time should be shortened as far as possible. These factors drive us to develop a new system structure, using mature and proven processing units to try to avoid the risks brought by the new system. Due to the gradual reduction of the price of external purchased parts, less and less investment in equipment, and shorter and shorter delivery time of equipment, it is often difficult for machine tool enterprises to make a choice to balance many factors from the automotive manufacturing industry
processing Diesel 122 silicone structure sealed engine cylinder block for construction adopts fully automatic honing manipulator for loading and unloading
consideration of capital
my material brand: pet-fr2300. They found that in automotive powertrain parts enterprises, although they use low labor cost manufacturing, this does not mean that a large number of manual operations are used for the transmission of parts rather than automation, or do not invest in the purchase of fast Efficient machine tool equipment
parallel machining process, program-controlled machining centers are grouped to form agile machining units
in China and Mexico, we have found that powertrain manufacturing enterprises are purchasing equipment with automatic loading and unloading manipulator, but in most cases, the transmission of parts between machine tools is still manual. Of course, the advantages of machine tools are mainly reflected in accuracy and reliability, which cannot be discounted
in a heavy truck factory in China, a complete agile processing system is adopted for the engine block made of cast iron. The processing system adopts 12 sets of worktables with hydraulic fixtures, 4 axes and 800mm table top × The 800mm Mega machining center is equipped with an exchange tray, which is manually loaded. The machining beat is 4S, and the linear speed of the machine tool is 80m/min. The rough machining of the cylinder body adopts high acceleration and efficient cutting, the part transmission between the machine tools of the machining center adopts power raceway transmission, and the fine milling and boring adopt a 12 station automatic line. This is a scalable system with an annual output of 15000 engine blocks
xt525 through machining center, in the form of machining units, is intended to fill the gap between the special machine and the machining center
in an engine production line in Mexico, 27 star 500 horizontal machining centers are used as the rough machining of the cylinder head, including the inspection of parts, the processing of positioning surfaces, the removal of blank casting risers, and the processing of process holes. The system also includes a vacuum tester to check the shrinkage of the casting blank. The machine tool is equipped with a loading and unloading manipulator. Adopting the design of our (cress h 焞 ler ex-cell-o lamb) standard, manufacturers can produce low-cost, reliable, easy to maintain machine tools that meet the processing quality and durability of products
in another gasoline engine manufacturer in China, 56 XS series horizontal machining centers are used for the processing of engine cylinder blocks and 48 machining centers are used for cylinder heads. These machine tools adopt automatic clamping mechanism, and the transmission of parts between machine tools is completed by power raceway. The processing system can produce two different types of products, each with an annual output of 150000 pieces and a total output of 300000 pieces
the cylinder head production line composed of 48 machining centers has a production beat of 108s and an output of 300000 pieces/year (two models)
the trend of process development
the process trend is a trick to achieve correct flexibility in the production of automotive industry. Parallel processing technology, that is, the scheme of multi station program-controlled machine tool composed of one or more processing units, is the best. Of course, other processing technologies, such as sequential processing technology and combined scheme, have also been widely used in engine block and other powertrain parts
1. Sequential processing technology
sequential processing technology (i.e. traditional automatic line) is still very popular in the automotive industry. This scheme must be adopted when the design of the product is not easy to change, or only a single change design is carried out, and when heavy cutting is adopted or the machining accuracy is required to be very high. The processing content of the special machine automatic line is completed in sequence according to the process allocation to different individual stations, and is connected by a rigid conveyor belt. Compared with machining centers, each process has less processing content (usually only one)
this processing system can be changed, but compared with the parallel processing system, its flexibility is still insufficient, and it is only suitable for producing products of the same "family" series. If the product changes significantly, the special machine automatic line is not a good choice. Sequential processing technology (such as special machine automatic line) has its advantages in product quality assurance. Because each process is "specialized", it can be well documented when quality problems occur in processing
2. Parallel processing technology
the advantage of parallel processing technology lies in its agility and scalability. When one equipment fails, the whole production line will not stop. However, the juxtaposition process does not have a strict quality inspection process. This flexible advantage of merging from multiple channels sometimes becomes the accumulation of "errors" brought by multiple channels, causing difficulties in tracing
parallel process, that is, the concept of forming machining units with machining centers, has advantages. We have succeeded in using the mixing process in the processing of cylinder blocks. The special machine automatic line is used for rough and finish machining with "constant" characteristics, while a group of machining centers (parallel process) is used for machining those characteristic factors that can be changed in design or for 4-cylinder and 6-cylinder co production. A parallel process, due to the use of separate equipment and repeated functions, can optimize the overall operational efficiency to 80% - 85%, which makes the effective utilization rate of machine tools as high as 90%
generally speaking, the effective utilization rate of special aircraft is lower, but we try to narrow this gap and make it close to the level of flexible units. A special aircraft line with an annual output of 600000 pieces will be transformed into three production lines with a slightly lower production capacity but higher reliability and a single line production capacity of 200000 pieces. Compared with a special machine line, such a solution can improve the effective utilization rate and simplify tool management and inventory management
3. Special machine machining center
a few years ago, an important innovative process concept - special machine machining center appeared, which combines the characteristics of automatic line and machining center to transform the machine tool into an independent machining unit
cross huler ex cel therefore, the test piece is a drum shaped l-o lamb designed processing unit after tightening, which eliminates the opposition between the special machine and the processing center, and makes up the gap between the special machine and the processing center. It is a new process to process the workpiece in the form of the combination of the processing center and the special machine. Special machine machining center uses a rotating c-axis to clamp the workpiece, and the fixture is similar to that of special machine line or machining center. The workpiece on the fixture can move axially between the X, y and Z axes or rotate. The tool spindle is arranged in a U-shape around the fixture, and the workpiece moves towards the tool during cutting. Tools include milling, multi spindle headstock, and even turning. Special machine machining center has fewer shafts than special machine, which makes it simpler and more reliable. Because the tool change time is reduced, the production capacity is higher than that of the machining center. Its initial investment and operation cycle are lower. Other advantages include small footprint, reduced inventory, installation and utility costs, and parts delivery costs
selection and comparison of several technologies
1. Comparison between linear motor and ball screw drive
the use of linear motor enables us to use a single tool to process large diameter holes through the axial feed of the tool and the method of differential compensation. Its remarkable advantage is that it does not need to use special tools, thus reducing the cost of tools. The precision and speed of the linear motor are higher than those of the traditional ball screw drive. Its moving speed can reach 120m/min, and the acceleration of the shaft is also very fast. For example, the chip to chip time of the linear motor machine tool of ex-cell-o can reach 2.6s
spech 550 duo double spindle machining center
however, in simple machining such as drilling installation holes, tapping, drilling cylinder head oil holes, ball screw drive still has its advantages. They are cheap and can meet the quality requirements
2. Comparison of MQL between wet machining and micro lubrication
relative to wet machining, people are more and more interested in MQL (minimum quantity lubrication). Micro lubrication can save the cost of treating iron filings and coolant, reduce the pollution of coolant to the environment, and accurately control the supply of lubricant in the cutting process, so that it can be mixed with air to form aerosol. Milling requires only a small amount of lubrication, while tapping and thread cutting require more. The precise supply system controlled by CNC is integrated with the spindle cover of the machine tool, and an appropriate amount of aerosol is provided to the cutting edge through the conveyor pipe
3. Comparison between single spindle and double spindle
in recent years, the comparison between single spindle and double spindle in turning has caused a lot of controversy. Europeans are accustomed to using double spindles because they can process two parts at the same time. For the machining of large stroke and large-size workpieces, Specht double spindle machining center is now used. A machine tool is equipped with two spindles, two clamps and two sets of tool exchangers at the same time, which improves the efficiency of the machine tool and reduces the floor area. In addition, installation and supporting costs, utility costs and coolant consumption have also been reduced
but is it easy to realize when it is a double spindle machine? When the bed breaks down, its processing efficiency is also lost twice at the same time. Therefore, the maintenance personnel need to be well trained to repair the machine tool in the shortest possible time
in North America, the concept of double spindle is still slowly accepted, and the complexity of repair and maintenance is the main reason for its wide use. In fact, more people are needed to repair a single spindle, because there are more potential downtime problems if one more machine tool is to be repaired
4. Challenge CGI (compacted graphite iron)
in diesel engines, the application of CGI materials is on the rise, and machine tool manufacturers are gradually looking for solutions to the processing of this hard material. When dealing with this thin-walled section (to reduce blank allowance and weight), we need a large torque spindle and a large feed force. The double ball screw of each axis of mega machine tool has sufficient feed thrust and hardness
in fact, perfect processing solutions do not exist, and each process has its own special features. The key to the problem is to find a system provider with extensive experience, who can help you optimize the processing technology, and reasonably select material conveying and cutting tools to meet the special needs of production. (end)
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