With the rapid upgrading of industrial structure and the continuous improvement of technological research and development capabilities, the Chinese construction machinery industry has made great strides in high-end, large-scale and intelligent products, which not only completely breaks the long-term reliance on imports of large-scale and super-large construction machinery products. And the leading enterprises in the construction machinery industry represented by Sany Heavy Industry, Zoomlion, and XCMG Group are showing a strong upward momentum and increasing influence in the international construction machinery industry. The world-class 500-ton, 1,200-ton class all-terrain crane, 2,000-ton crawler crane, the world's longest boom concrete pump truck, and the world's largest horizontal boom slewing D5200-240 tower crane and other products The emergence of various industries has made China's construction machinery industry a representative of China's equipment manufacturing industry with the highest level and strongest core capabilities.
However, as Jun Jun, the chairman of the China Construction Machinery Industry Association, frankly stated that although China's construction machinery companies have made great progress over the years, there are still many advanced foreign companies in terms of technological level, technological innovation capability and product level. Not a small gap. China's construction machinery industry must focus on restructuring and development as the main line, vigorously promote the "adjustment transformation, innovation and upgrading" strategy, through the development of high-end, large-scale, intelligent construction machinery and key supporting system areas, to promote healthy and sustained rapid industry development of.
It should be soberly noticed that China’s construction machinery technology upgrades are mainly based on the external introduction of digestion and absorption. There are few original innovations and integrated innovation needs to be strengthened. In contrast with the rapid development of mainframe products, the development of basic components and basic processes has been lagging behind. The quality of basic components such as engines, transmissions, drive axles, high-pressure and large-flow pumps, valves, seals, and high-strength fasteners that are compatible with the host system is poor, and the specifications and specifications are incomplete. Special raw materials and other products have long been dependent on imports. China’s construction machinery must demonstrate competitiveness at a higher level. This “imperfection†must go forward.
The weak foundation has caused the technological “hollow†key components and the development of basic technologies to lag behind. It has become the “bottleneck†factor that has constrained the Chinese construction machinery industry to further enhance its competitiveness. To a certain extent, it has even become a difficult to crack. "Death knot."
Take an excavator for example. At present, the model of domestic excavator production is roughly as follows: Product integration supported by domestic and foreign purchaseable resources. In other words, the product is assembled from the "U.S. engine, the hydraulic system of Germany, the electronic control system of Japan, plus the domestic frame structure." Or is the "introduction - mapping - mapping - assembly - improvement - molding" cloning model. In the core work department and key components of the product, there is a large gap in the level of domestic products. This makes the "shanzhai" phenomenon of domestic brand excavators widespread. Because the key parts are subject to human beings, it is naturally a helpless choice for the production process. However, as a product manufacturer and assembler who just do not master the core technology, its development or sustainability is clearly insecure.
Some people in the industry pointed out that the current situation is not just to explore the issue of how to improve the level of key components, but to actively explore the issue of how long it will take to catch up with the world's advanced level.
It is reported that companies such as Sany Heavy Industry, Zoomlion, and Liugong have invested a lot of effort in developing high-pressure hydraulic devices. Some commentators believe that from the current R&D capabilities and progress of various companies, it will take three to five years or even longer to realize the local industrialization of high-level hydraulic devices. At the same time, however, some foreign-funded enterprises are accelerating the pace of investment and construction in China. Once the dominant position of such “monopolistic products†continues to be strengthened, the consequences for domestic companies are not hard to imagine.
In the opinion of experts, there are still many deficiencies in the independent innovation of construction machinery manufacturing:
The first is that there is a problem with the source of technology. In the technology supply chain of construction machinery manufacturing, the technology of an enterprise generally has three sources: it is provided by the public technology research platform of the society; the technology is formed through the introduction of technology and digestion and absorption of the enterprise; and the original technology of the enterprise is independent. With the reform of the science and technology system, research institutions originally belonging to the public nature of the industrial sector were transformed into enterprises. The determination of the operational status made it impossible for them to undertake common technical research. This makes the part of the original function of providing common technology for the majority of companies and providing technology to the industry. At the same time, from the country's entire innovation system, the industry's innovation system is lacking, resulting in the absence of structural common technical research. To solve this problem, it depends on the involvement and support of public resources.
Second, as the main body of independent innovation, but also the most active company, the role played in the innovation process is obviously insufficient. At present, the intensity of investment in R&D funds for domestic companies is low. Although there has been a marked increase over the past, the gap is far from those of foreign competitors. For example, the lack of high-performance benches and test methods is considered to be an important factor that restricts the development of the industry. Insiders pointed out that at present, domestic companies generally lack sophisticated technology, and the key is that the investment in experimental and testing platforms is not enough. The lack of experimentation has led to insufficient accumulation of data. Without database support, innovation has no way of talking about. Perhaps aware of this, some of the 10 million-level experimental stations have recently been built.
What is Precision CNC Milling
In general, computer numerical control milling machine (CNC) machining is a deductive manufacturing technique that programs 3-axis linkage, complex to 5-axis linkage, drives milling cutters to remove layers from solid blocks called blanks to produce finished parts. CNC milling is one of the main types of CNC Machining, which uses cutting tools that rotate at a speed of several thousand to tens of thousands of revolutions per minute (RPM) to precisely remove materials to obtain parts with complex surfaces. In addition to milling, CNC machining is also equipped with drills, boring tools, thread cutters and other tools to complete different part features at once. CNC machining produces parts based on a computer-aided design (CAD) model that is sent to a CNC machine through computer-aided manufacturing (CAM) software.
CNC Machining centers developed from CNC milling machines. The biggest difference compare to CNC milling machines is that the machining center has the ability to automatically exchange machining tools, by installing tools for different purposes on the tool magazine, the machining tools on the spindle can be changed through the automatic tool changing device in a single clamping device to achieve a variety of machining functions.
|
CNC Milling Finish |
|
|
Process |
Roughness Ra(um) |
|
Cylindrical milling cutter milling (rough) |
12.5~3.2 |
|
Cylindrical milling cutter (fine) |
3.2~0.8 |
|
Cylindrical milling cutter (precision) |
0.8~0.4 |
|
Cylindrical milling cutter (rough) |
12.5~3.2 |
|
Cylindrical milling cutter milling (fine) |
3.2~0.8 |
|
Cylindrical milling cutter milling (precision) |
0.8~0.4 |
|
Cutter milling (fine) |
12.5~3.2 |
|
End milling cutter (rough) |
3.2~0.4 |
|
End milling cutter (precision) |
0.8~0.2 |
|
High speed milling (rough) |
1.6~0.8 |
|
High speed milling (fine) |
0.4~0.2 |
CNC milling accuracy
CNC milling centers and high-Precision Machining centers. Ordinary machining center, resolution of 1μm, maximum feed speed of 15 ~ 25m / min, positioning accuracy of about 0μm. High-precision machining center, resolution of 0.1μm, maximum feed speed of 15 ~ 100m / min, positioning accuracy of about 2μm. Between 2 and 10 μm, with a ± 5 μm more, can be called precision grade. FCE equipped with different grade and different size CNC milling center. Take in to account into both economic and quality in parallel.
CNC Finishing surface treatment
Post-processing is the final step in the CNC machining process. In a quick guide, we offer a lot of surface treatments to complete your final parts and get them to meet strict specific requirements. It should be noted that in CNC machining, post-processing is in optional, as the quality of the machined parts is already very high.
Anodized
The anodizing process allows the part to obtain excellent corrosion resistance, increasing the hardness and wear resistance of the surface. Anodizing is also the most common pre-painting treatment, which can help the painted surface to obtain good adhesion. We typically apply two types of anodizing in our production: Type II, corrosion resistant; Type III is thicker, adding a layer of wear resistance. Both anodizing processes can achieve a variety of color effects.
Polishing
Grinding polish, it offers the fastest turnaround parts and does not require post-processing. The surface finish of the grinding part is equivalent to 125 um in Ra, and the requirements can be increased to 63, 32 or 16 um Ra. Minor tool marks may still be visible on the last part.
Powder coatings
Powder Coating is thermoplastic powder spraying directly on the processed part. The sprayed parts are then baked in an oven to form a durable, abrasion- and corrosion-resistant plastic coating. In the powder coating process, its color, brightness, surface roughness can be customized.
Shot blasting
Shot peening is the high-speed spraying of beads of different hardnesses and sizes onto the surface of the part. To get different textures and brightness of the surface. Since the surface has been hit by similar forging beads, the hardness and wear resistance of the surface have also been enhanced.
Design of CNC machining
CNC machining is a universal machining process, especially parts that can be cut and machined can be achieved through CNC, from simple shape shapes to complex curved structures. However, as with every manufacturing technique, CNC machining has some design limitations. We break them down as follows to ensure that your products are optimally designed to better fit the CNC machining process.
General Tolerance
When designing parts, the size of each part is different according to the application environment, working conditions, etc., and the requirements for the machining accuracy of the workpiece are also different. Although CNC machining can achieve very high machining accuracy, we should also be aware that demanding machining accuracy and accuracy (strict product tolerances) usually mean Longer production times and higher costs. If a specific tolerance is not specified in the product design, we recommend choosing at the following levels.
|
Permissible deviations in mm for ranges in nominal lengths |
Tolerance Class Designation(Description) |
|||
|
fine |
medium |
coarse |
very coarse |
|
|
0.5 up to 3 |
±0.05 |
±0.1 |
±0.2 |
-- |
|
over 3 up to 6 |
±0.05 |
±0.1 |
±0.3 |
±0.5 |
|
over 6 up to 30 |
±0.1 |
±0.2 |
±0.5 |
±1.0 |
|
over30up to 120 |
±0.15 |
±0.3 |
±0.8 |
±1.5 |
|
over120upto400 |
±0.2 |
±0.5 |
±1.2 |
±2.5 |
|
over 400up to 1000 |
±0.3 |
±0.8 |
±2.0 |
±4.0 |
|
over 1000up to 2000 |
±0.5 |
±1.2 |
±3.0 |
±6.0 |
|
over 2000 up to 4000 |
-- |
±2.0 |
±4.0 |
±8.0 |
The highest precision of our equipment is 0.001, and the recommended most precise machining requirements do not exceed +/-0.005mm
Interior angle
All internal vertical edges of our products need to have rounded corners instead of right angles. This is because the tools used in CNC milling are cylindrical, which means they cannot produce inner right-angled edges. The fillet required by this process is called the inner corner fillet. When designing parts, the larger the inner corner fillet, the more efficient the production process. Because of the larger fillets, larger diameter milling cutters can be used to increase milling speed, and fewer swaps can be made to improve accuracy.
Undercut
Undercut cannot be machined with standard milling cutters, so the use of retract slots for parts should be avoided when designing CNC machined parts. In particular, for non-standard inner contour shapes, customized machining tools are required, which will greatly increase processing time and costs. Secondly, if undercut can not be avoided, due to the limited length of cnc tools, the undercut can not be too deep. If they are too deep or the location is difficult to reach, they will not be able to be produced because the CNC tool cannot reach the machining location.
Chamber wall thickness
CNC machining requires your part design to meet minimum wall thickness requirements. In general, it is recommended to choose the thickest possible and avoid very thin or characteristic walls. This is because CNC tools processing thin-walled parts will cause vibration deformation, which may cause interruptions or damage, and the size is out of specification. The standard minimum wall thickness for CNC machined metals is 0.030" (0.76 mm) and for plastics is 0.060" (1.5 mm).
Thread
When designing parts, it is useful to choose the largest possible thread size because smaller taps have a higher risk of breaking during production. If possible, avoid using deep hole threads as they lead to higher production costs, especially when custom tools are required.
Metal
In principle, materials with high hardness are easier to process because better processing accuracy can be obtained, but they are limited by the hardness of processing tools, so the hardness of the generally recommended parts is 8 ~ 60HRC, and for metal materials, the hardness is greater than stainless steel Followed by cast iron, followed by copper, and finally aluminum, while the processing of ceramics, plastics, etc. belongs to the processing of non-metallic materials. Fast production time.
Polymer
Although CNC can process thermoplastics, the material properties of polymers still have many difficulties for CNC processing. First, due to poor thermal conductivity, many thermoplastics melt or bend when in contact with CNC milling machines or drill bits. Secondly, the processing of plastics, because the hardness is low, the size accuracy caused by the knife during product clamping and processing is not high. For those parts that do not have special requirements for the strength and hardness of the metal, thermoplastics can provide a cheaper alternative.
Cost optimization of machined products
Simplify product design
Simplifying product design while taking into account functionality usually saves production time and reduces production costs. Because the manufacture of complex structures and surfaces often requires complex longer passes, more layering to obtain the same fine contour quality. This means higher production costs.
Reduce cutter changes
Using the same milling machine machining features, larger and same internal fillets, can reduce the number of tools used to reduce machining time. For example, if a workpiece needs a 10mm end face milling cutter to process some features, it also needs a spherical milling cutter to process a curved surface, and a 2mm milling cutter to process a fine groove, which will require repeated tool changes and reduce the machining efficiency
Proper material selection
The choice of raw material for machining can have a significant impact on production time and costs for CNC machining. If possible, choose a material with good processability, such as brass or aluminum. For those applications that do not require metal hardness and strength, CNC machining of engineering plastics like PMMA and ABS also helps to reduce costs because the material blank is cheaper, and the processing efficiency is higher.
Tolerance and wall thickness
Higher tolerances and thinner wall thicknesses also increase THE CORRESPONDING CNC machining costs, as it takes time to achieve higher precision cutting. If your product or component can accept a larger size range, choose a lower tolerance to reduce production time and costs. The same is true for wall thickness: a larger wall thickness margin should be chosen.
Choice of surface treatment
Surface treatment is often the final stage of the CNC machining process, which can also affect the cost of your entire project. Choosing less surface treatment for your part or product can lead to better time and cost efficiency. FCE can recommend to you how to optimize the surface treatment to balance the conflict between cost and quality according to your final needs.
FCE Machining services
FCE facilities are equipped with the most advanced and highest precision 3, 4 and 5-axis CNC machines, which allows us to complete your order in record time
1. 15+ year work experience engineers
2. Fastest 5 days delivery
3. Prototypes can be machined as quickly as 1 day.
4. More than 200 metals and plastics material available in stock
5. Tolerances as low as +-0.005mm
6. ISO 9001: 2015 certified factory
7. 40+ CNC machines
8. 50,000+ machined parts per month
We cooperated with many world top 500 companies and awarded good responds alway
Injection Molding,Plastic Injection,Plastic Molding,Custom Injection Molding
Suzhou FCE precision electronics Co., LTD , https://www.fukeyifcesz.com