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With the arrival of the world's fourth industrial revolution, and the continuous development of science and technology and social production, mechanical manufacturing technology has undergone profound changes, the structure of mechanical products is more and more reasonable, and its performance, accuracy and efficiency are increasingly improved, so the production equipment of processing mechanical products has put forward high performance, high precision and high automation requirements. In order to solve the problem that ordinary machine tools can not be produced, to achieve single and small batch production, especially the automatic processing of some complex parts, CNC machining came into being.
Although, at present, China has become a processing country, precision parts processing plants all over the country. According to the data of the General Administration of Customs of China, in January and February 2023, the cumulative export volume of China's machine tools reached 2364123 units (2,364,100 units), from high-end CNC customized precision parts to ordinary standard products can achieve standardized mass production, the application of CNC technology can realize the automatic processing of parts and improve production efficiency. Especially in the automotive manufacturing, aerospace, electronic equipment manufacturing and other fields, the application of CNC technology has great potential. The application of CNC technology can realize the automatic processing of parts and improve production efficiency. Especially in the automotive manufacturing, electronic equipment manufacturing and other fields, the application of CNC technology has great potential.
CNC machining is widely used in the field of automotive parts, involving the engine, transmission, chassis, braking system, steering system and other aspects. However, no matter in any field of precision machining, achieving high precision and high speed is an important competitive means to obtain user orders.
The following are some specific applications of CNC machining in the field of automotive parts:
Engine parts machining: CNC machining can be used to manufacture various parts of the engine such as cylinder block, crankshaft, connecting rod, valve seat, etc., which require high precision and high strength.
1.Transmission parts processing: CNC machining can be used to manufacture various parts of the transmission system such as transmission gears, clutches, transmission shafts, etc., which require high precision and high strength.
2.Brake parts processing: CNC machining can be used to manufacture various parts of the brake system such as brake discs, brake pads, brakes, etc., which require high precision and high quality.
3.Steering parts processing: CNC machining can be used to manufacture various parts of the steering system such as steering gear, steering rod, steering machine, etc., these parts need high precision and high strength.
With the continuous development of CNC machining technology and the expansion of application fields, whether it is automobile body design or automobile internal electronic parts processing, the application range of CNC custom machining technology in the field of automation will be more and more extensive. In the future, CNC machining technology will continue to play an important role in the automotive manufacturing field.
Precision machinery parts processing plays a crucial role in various industries, including aerospace, automotive, medical, and manufacturing.Precision machinery parts have specific requirements to ensure optimal performance.One crucial aspect is the material used for processing. If the hardness of the material being processed surpasses that of the lathe tool, it can potentially cause irreparable damage.Therefore, it is essential to select materials that are compatible with precision machining.
1. Material Strength and Durability
One of the key requirements of precision machinery parts processing is material strength and durability.Machinery parts often undergo significant stress and pressure during operation, and the selected materials must be able to withstand these forces without deforming or breaking.For example, aerospace components require materials with high strength-to-weight ratios, such as titanium alloys, to ensure structural integrity and reliability.
2. Dimensional Stability
Precision machinery parts must maintain their dimensional stability even under extreme operating conditions.The materials used in their processing should possess low thermal expansion coefficients, allowing the parts to retain their shape and size without warping or distorting due to temperature fluctuations.Steels with low thermal expansion coefficients, such as tool steel or stainless steel, are commonly preferred for precision machinery parts subjected to varying thermal conditions.
3.Wear and Corrosion Resistance
Precision machinery parts often interact with other components or environments that can cause wear and corrosion.The materials chosen for their processing should exhibit excellent wear resistance to withstand constant friction and minimize surface damage.Additionally, corrosion resistance is crucial to ensure the longevity of the parts, especially in industries where exposure to moisture, chemicals, or harsh environments is common.Materials such as hardened steel, stainless steel, or certain grades of aluminum alloys are frequently utilized to enhance wear and corrosion resistance.
4.Machinability
Efficient and precise machining is a critical factor in the manufacturing of precision machinery parts.The material selected for processing should possess good machinability, allowing it to be easily cut, drilled, or shaped into the desired form with minimal tool wear.Materials like aluminum alloys with excellent machinability properties are often preferred for their versatility and ease of shaping into complex geometries.
5.Thermal Conductivity
Thermal management is significant in precision machinery parts processing, as excessive heat can adversely affect performance and increase the risk of failure.Materials with high thermal conductivity, such as copper alloys or certain grades of aluminum, help dissipate heat efficiently, preventing localized temperature rise and ensuring optimal operating conditions.
6.Cost-Effectiveness
While meeting the specific requirements is crucial, cost-effectiveness is also an important consideration in precision machinery parts processing.The selected materials should strike a balance between performance and cost, ensuring that the final product remains economically viable without compromising quality.Conducting a cost-benefit analysis and considering factors like material availability, processing complexity, and overall project budget can aid in making informed decisions regarding material selection.
Precision parts processed with stainless steel have the advantages of corrosion resistance, long service life and good mechanical and dimensional stability, and austenitic stainless steel precision parts have been widely used in medical, instrumentation and other precision machinery fields.
The reasons why stainless steel material affects the machining accuracy of parts
The exceptional strength of stainless steel, coupled with its impressive plasticity and noticeable work hardening phenomenon, result in a significant disparity in cutting force when compared to carbon steel. In fact, the cutting force required for stainless steel surpasses that of carbon steel by more than 25%.
At the same time, the thermal conductivity of stainless steel is only one-third of that of carbon steel, and the cutting process temperature is high, which makes the milling process deteriorate.
The growing machining hardening trend observed in stainless steel materials demands our serious attention. During milling, the intermittent cutting process leads to excessive impact and vibration, resulting in substantial wear and collapse of the milling cutter. Furthermore, the use of small-diameter end milling cutters poses a higher risk of breakage. Significantly, the decrease in tool durability during the milling process adversely affects the surface roughness and dimensional accuracy of precision parts machined from stainless steel materials, rendering them unable to meet the required standards.
Stainless steel precision parts processing precision solutions
In the past, traditional machine tools had limited success in machining stainless steel parts, particularly when it came to small precision components. This posed a major challenge for manufacturers. However, the emergence of CNC machining technology has revolutionized the machining process. With the aid of advanced ceramic and alloy coating tools, CNC machining has successfully taken on the complex task of processing numerous stainless steel precision parts. This breakthrough has not only improved the machining accuracy of stainless steel components but has also significantly enhanced the efficiency of the process. As a result, manufacturers can now rely on CNC machining to achieve precise and efficient production of stainless steel precision parts.
As an industry-leading manufacturer in precision machinery parts processing, HONSCN understands the significance of material requirements in delivering exceptional products. We prioritize using high-quality materials that meet all specific requirements, guaranteeing superior performance, durability, and reliability. Our team of experienced professionals meticulously evaluates each project's unique needs, selecting the most suitable materials to ensure customer satisfaction and industry-leading solutions.
In conclusion, precision machinery parts processing demands careful consideration of the materials used. From strength and durability to wear resistance and machinability, each requirement plays a vital role in achieving high-quality products. By understanding and meeting these specific material requirements, manufacturers can produce precision machinery parts that excel in performance, reliability, and longevity. Trust HONSCN for all your precision machinery parts processing needs, as we strive to deliver excellence through meticulous material selection and exceptional manufacturing expertise.
With the increasingly updated processing technology, CNC machining has also undergone a lot of changes. Many experts pointed out that in the future, CNC will be the mainstream processing mode. In the CNC machining process, the tool is the most important, today, we will understand the CNC tool in detail.
A tool is a tool used for cutting in mechanical manufacturing. Generalized cutting tools include both cutting tools and abrasive tools. The vast majority of knives are used for machines, but there are also hand tools. Since the tools used in mechanical manufacturing are basically used to cut metal materials, the term "tool" is generally understood as a metal cutting tool. The cutting tools used for cutting wood are called woodworking tools.
Tool classification
Cutting tools can be divided into five categories according to the form of the workpiece machined surface.
Cutting tools for processing various outer surfaces, including cutting tools for processing various outer surfaces, including turning tools, planing knives, milling cutters, outer surface broach and file, etc.
Hole processing tools, including drill, reaming drill, boring cutter, milling cutter and internal surface broach, etc.
Thread processing tools, including tap, die, automatic opening thread cutting head, thread turning tool and thread milling cutter.
Gear processing tools, including hob, gear shaper cutter, shaving cutter, bevel gear processing tool, etc.
Cutting tools, including inserted circular saw blade, band saw, bow saw, cutting tool and saw blade milling cutter, etc.
In addition, there are combination tools.
Tool structure
The structure of various tools is composed of a clamping part and a working part. The clamping part and working part of the overall structure of the tool are done on the tool body; The working part of the tool (the tooth or blade) is mounted on the tool body.
The clamping part of the tool has two kinds of holes and handles. The tool with hole relies on the inner hole set on the spindle or mandrel of the machine tool, and transmits the torsional torque with the help of the axial key or the end key, such as the cylindrical milling cutter and the sleeve face milling cutter.
The tool with the handle is usually rectangular handle, cylindrical handle and conical handle three kinds. Turning tools, planing tools, etc. are generally rectangular handles; The conical handle withstands the axial thrust with the taper and transmits the torque with the help of friction. Cylindrical shank is generally suitable for smaller twist drill, end mill and other tools, cutting with the help of the friction generated when clamping torque transfer. The shank of many tools with handles is made of low alloy steel, and the working part is made of high speed steel welded to each other.
The basic properties that the tool material should have
1. High hardness
The hardness of the tool material must be higher than the hardness of the workpiece material to be machined, which is the basic feature that the tool material should have.
2. Sufficient strength and toughness
The material of the cutting part of the tool must withstand great cutting force and impact force when cutting. The bending strength and impact toughness reflect the ability of tool material to resist brittle fracture and edge breakage.
3. High wear resistance and heat resistance
The wear resistance of tool materials refers to the ability to resist wear. The higher the hardness of the tool material, the better the wear resistance; The higher the high temperature hardness, the better the heat resistance, the tool material at high temperature resistance to plastic deformation, anti-wear ability is also stronger.
4. Good thermal conductivity
Large thermal conductivity means good thermal conductivity, and the heat capacity generated during cutting is easily transmitted out, thereby reducing the temperature of the cutting part and reducing tool wear.
5. Good technology and economy
In order to facilitate manufacturing, the tool material is required to have good machinability, including forging, welding, cutting, heat treatment, grindability and so on. Economy is one of the important indexes to evaluate and promote the application of new tool materials.
6. Resistance to bonding
Prevent the workpiece and the tool material molecules under the action of high temperature and high pressure adsorption bond.
7. Chemical stability
It means that the tool material is not easy to react chemically with the surrounding medium at high temperature.
Tool coating
Aluminum alloy indexable inserts are now coated with hard or composite layers of titanium carbide, titanium nitride, alumina by chemical vapor deposition. The physical vapor deposition method that is being developed can be used not only for aluminum alloy tools, but also for high-speed steel tools such as drills, hobs, taps and milling cutters. As a barrier that prevents chemical diffusion and heat conduction, the hard coating slows down the wear rate of the tool during cutting, and the life of the coated blade is about 1 to 3 times higher than that of the uncoated blade.
Tool selection is carried out in the human-machine interaction state of NC programming. The tool and handle should be correctly selected according to the machining capacity of the machine tool, the performance of the workpiece material, the processing procedure, the cutting amount and other relevant factors.
The general principle of tool selection: easy installation and adjustment, good rigidity, high durability and accuracy. On the premise of meeting the processing requirements, try to choose a shorter tool handle to improve the rigidity of the tool processing. When selecting the tool, the size of the tool should be adapted to the surface size of the workpiece to be machined.
1. End milling cutter is often used to process the peripheral outline of plane parts.
2. When milling the plane, carbide blade milling cutter should be selected.
3. When processing convex and grooves, choose high-speed steel end milling cutter.
4. When processing the blank surface or roughing the hole, you can choose the corn milling cutter with cemented carbide blade.
5. For the processing of some vertical surface and variable bevel contour, ball end milling cutter, ring milling cutter, conical milling cutter and disk milling cutter are often used.
6. In the processing of free-form surface, because the cutting speed of the end of the ball head tool is zero, so in order to ensure the processing accuracy, the cutting line spacing is generally very dense, so the ball head is often used in the finishing of the surface.
7, flat head tool in the surface processing quality and cutting efficiency are better than the ball head knife, therefore, as long as the premise of ensuring but cutting, whether it is rough surface machining or finishing, should be preferred to choose flat head knife.
8. In the machining center, various tools are installed on the tool library, and the tool selection and tool change are carried out at any time according to the procedure. Therefore, the standard tool handle must be used in order to make the standard tool for drilling, boring, expanding, milling and other processes quickly and accurately installed on the machine spindle or tool library. The number of tools should be reduced as far as possible; After a tool is installed, it should complete all the processing parts that it can carry out; Rough finishing tools should be used separately, even if the same size specifications of the tool; Milling before drilling; Surface finishing is carried out first, and then 2D contour finishing is carried out. Where possible, the automatic tool change function of CNC machine tools should be used as much as possible to improve production efficiency.
Problems encountered in processing aluminum and solutions when processing pure aluminum, easy to stick knife analysis and solutions:
1. Aluminum material is soft in texture and easy to stick at high temperature;
2. Aluminum is not resistant to high temperature, easy to open;
3. Related to processing cutting fluid: good oil lubrication performance; Good water-soluble cooling performance; High dry cutting cost;
4. When processing pure aluminum, the end mill dedicated to aluminum processing should be selected: positive front Angle, sharp cutting edge, large chip discharge slot, 45 degrees or 55 degrees helix Angle;
5. The material of the workpiece and the CNC tool has a greater affinity.
6. Rough front tool processing soft materials.
Recommendation: Machine tool conditions are poor to good requirements are low to high, please use high-speed steel, coated polished carbide, PCD polycrystalline diamond and single crystal diamond.
7. Low speed can be avoided by cutting fluid, high speed oil mist lubrication, the effect can be improved, aluminum alloy suitable
Due to the high temperature, high pressure, high speed, and the parts working in the corrosive fluid medium, the application of difficult to process more and more materials, the automation level of cutting processing and the processing accuracy requirements are getting higher and higher. In order to adapt to this situation, the development direction of the tool will be the development and application of new tool materials; Further develop the vapor deposition coating technology of the tool, and deposit higher hardness coating on the matrix of high toughness and high strength, so as to better solve the contradiction between hardness and strength of the tool material; Further development of indexable tool structure; Improve the manufacturing accuracy of the tool, reduce the difference in product quality, and optimize the use of the tool.How to choose CNC aluminum alloy machining tool.
General steps of plastic parts designPlastic parts are designed on the basis of industrial modeling. First, see whether there are similar products for reference, and then carry out detailed functional decomposition of products and parts to determine the main process problems such as parts folding, wall thickness, demoulding slope, transition treatment between parts, connection treatment and strength treatment of parts.1. Similar reference
Before design, first look for similar products of the company and peers, what problems and deficiencies have occurred in the original products, and refer to the existing mature structure to avoid problematic structural forms.2. Determine the part discount, transition, connection and clearance treatment between partsUnderstand the modeling style from the modeling drawing and effect drawing, cooperate with the functional decomposition of the product, determine the number of parts (different surface states are either divided into different parts, or there must be over treatment between different surfaces), determine the over treatment between parts' surfaces, and determine the connection mode and fit clearance between parts.
3. Determination of part strength and connection strengthDetermine the wall thickness of the part body according to the product size. The strength of the part itself is determined by the wall thickness of the plastic part, the structural form (the plastic part in the shape of a flat plate has the worst strength), the stiffener and the stiffener. While determining the single strength of parts, the connection strength between parts must be determined. The methods to change the connection strength include: adding screw column, adding stop, adding buckle position and adding reinforcing bone against top and bottom.4. Determination of demoulding slope
The demoulding slope shall be comprehensively determined according to the material (PP, PE silica gel and rubber can be demoulded forcibly), surface state (the slope of decorative grain shall be greater than that of smooth surface, and the slope of etched surface shall be 0.5 degrees greater than that required by the template as far as possible, so as to ensure that the etched surface will not be damaged and improve the yield of products), transparency or not determines the demoulding slope of parts (the transparent slope shall be greater).Material types recommended by different product series of the companySurface treatment of plastic parts
Wall thickness selection of plastic partsFor plastic parts, the uniformity of wall thickness is required, and the workpiece with uneven wall thickness will have shrinkage traces. It is required that the ratio of stiffener to main wall thickness should be less than 0.4, and the maximum ratio should not exceed 0.6.Demoulding slope of plastic parts
In the construction of stereoscopic drawing, where the appearance and assembly are affected, the slope needs to be drawn, and the slope is generally not drawn for stiffeners.The demoulding slope of plastic parts is determined by the material, surface decoration status and whether the parts are transparent or not. The demoulding slope of hard plastic is greater than that of soft plastic. The higher the part, the deeper the hole, and the smaller the slope.Recommended demoulding slope for different materials
Numerical values of different accuracy in different size rangesDimensional accuracy of plastic partsGenerally, the accuracy of plastic parts is not high. In practical use, we mainly check the assembly dimensions, and mainly mark the overall dimensions, assembly dimensions and other dimensions that need to be controlled on the plan.
In practice, we mainly consider the consistency of dimensions. The edges of the upper and lower covers need to be aligned.Economic accuracy of different materialsNumerical values of different accuracy in different size ranges
Surface roughness of plastics1) The roughness of the etched surface cannot be marked. Where the plastic surface finish is particularly high, circle this range and mark the surface state as mirror.2) The surface of plastic parts is generally smooth and bright, and the surface roughness is generally ra2.5 0.2um.
3) The surface roughness of plastic mainly depends on the surface roughness of mold cavity. The surface roughness of mold is required to be one to two levels higher than that of plastic parts. The mold surface can reach ra0.05 by ultrasonic and electrolytic polishing.FilletThe fillet value of injection molding is determined by the adjacent wall thickness, generally 0.5 1.5 times of the wall thickness, but not less than 0.5mm.
The position of the parting surface shall be carefully selected. There is a fillet on the parting surface, and the fillet part shall be on the other side of the die. It is difficult to make, and there are fine trace lines at the fillet. However, fillet is required when anti cutting hand is required.Stiffener problemThe injection molding process is similar to the casting process. The non-uniformity of wall thickness will produce shrinkage defects. Generally, the wall thickness of reinforcement is 0.4 times of the main body thickness, and the maximum is no more than 0.6 times. The spacing between bars is greater than 4T, and the height of bars is less than 3T. In the method of improving the strength of parts, it is generally reinforced without increasing the wall thickness.
The reinforcement of the screw column shall be at least 1.0mm lower than the end face of the column, and the reinforcement shall be at least 1.0mm lower than the part surface or the parting surface.When multiple bars intersect, pay attention to the non-uniformity of wall thickness caused by the intersection.Design of stiffeners for plastic parts
Bearing surfacePlastic is easy to deform. In terms of positioning, it should be classified as the positioning of wool embryo. In terms of positioning area, it should be small. For example, the support of plane should be changed into small convex points and convex rings.Oblique roof and row position
The inclined top and row position move in the parting direction and perpendicular to the parting direction. The inclined top and row position shall be perpendicular to the parting direction, and there shall be sufficient movement space, as shown in the following figure:Treatment of plastic limit process problems1) Special treatment of wall thickness
For particularly large workpieces, such as the shell of toy cars, the wall thickness can be relatively thin by using the method of multi-point glue feeding. The local glue position of the column is thick, which is treated as shown in the following figure.Special treatment of wall thickness2) Treatment of small slope and vertical surface
The die surface has high dimensional accuracy, high surface finish, small demoulding resistance and small demoulding slope. In order to achieve this purpose, the parts with small inclination of the workpiece are inserted separately, and the inserts are processed by wire cutting and grinding, as shown in the figure below.To ensure that the side wall is vertical, the running position or inclined top is required. There is an interface line at the running position. In order to avoid obvious interface, the wiring is generally placed at the junction of fillet and large surface.Treatment of small slope and vertical surface
To ensure that the side wall is vertical, the running position or inclined top is required. There is an interface line at the running position. In order to avoid obvious interface, the wiring is generally placed at the junction of fillet and large surface.Problems often to be solved for plastic parts1) Transition processing problem
The accuracy of plastic parts is generally not high. There must be transition treatment between adjacent parts and different surfaces of the same part.Small grooves are generally used for transition between different surfaces of the same part, and small grooves and high-low staggered surfaces can be used between different parts, as shown in the figure.Surface over treatment
2) Clearance value of plastic partsParts are directly assembled without movement, generally 0.1mm;The seam is generally 0.15mm;
The minimum clearance between parts without contact is 0.3mm, generally 0.5mm.3) The common forms and clearance of plastic parts are shown in the figureCommon forms and clearance taking method of stop of plastic parts
1. Fault phenomenonWhen changing the knife, the manipulator is stuck and cannot change the knife. The position of the manipulator for changing the knife is offset, and the knife is changed.2 fault analysis and treatment
2.1 tool change principleThe machining center is a rotary tool magazine, and the tool change mechanism is cam type. The tool change process is as follows:(1) Write m06t01 to start the tool change and tool selection cycle.
(2) The spindle will stop at the oriented spindle stop point, the coolant stops, and the z-axis moves to the tool change position (second reference point).(3) Select the tool. After NC compiles it to PLC according to the t command, start selecting the tool. The tool magazine motor rotates and rotates the target tool number to the tool change point of the tool magazine. Note that the t command is the tool sleeve position of the tool magazine at this time.(4) The tool change motor drives the cam mechanism to rotate 90 from the parking position to grasp the tool in the effective tool sleeve and the tool in the spindle. At the same time, detect the change of the proximity switch state of the cam mechanism, the PMC output sends out the tool loosening command, the tool magazine tool sleeve tool loosening and the spindle tool loosening solenoid valve are powered on, the cam continues to rotate, drive the manipulator down, push down the tool handle and prepare for exchange. As shown in Figure 1.
(5) The manipulator rotates 180 to exchange the tool, the cam continues to move upward, install the tool into the spindle, and install the tool on the original spindle into the tool sleeve at the tool change position of the tool magazine. At the same time, the detection switch sends a tool tightening command to PMC, the solenoid valve loses power, the shaft tool handle is clamped, the butterfly spring retracts, and the spindle tool is clamped.(6) Change to the manipulator, continue to rotate 90 , and stop completing a set of tool change actions.2.2 fault analysis
Change the tool to the fourth step of 2.1. The tool change manipulator is stuck, and the spindle has been loosened for blowing, but the tool cannot be pulled out. Cut off the power and manually turn the tool change motor. After completing a tool change action, manually load and unload the tool, the action is normal, and the problems of spindle tightening tool are preliminarily eliminated. When the tool change process is performed again, the manipulator gets stuck and the manipulator claw at the tool magazine falls off. After the tool change is found, the manipulator installs the tool on the spindle and the position is offset, as shown in Figure 2.
After the tool is removed, it is found that the action is normal. The reason for this situation may be the offset between the manipulator and the spindle, or the deviation of the accuracy of the manipulator axis relative to the spindle axis, and the inaccurate positioning of the spindle will also lead to the offset of the tool change position. Implement the tool change action step by step, check the accurate positioning of the spindle, and eliminate the fault caused by inaccurate positioning. According to the table, the mechanicalThe axial position and rotation center distance of hand, knife sleeve and spindle are consistent, so the fault of mechanical jamming of mechanical mobile phone is also eliminated.
Recently, this machine tool mainly processes stainless steel and other material workpieces, with large cutting volume and heavy load. It runs under re cutting for a long time. It is found that the manipulator is not loose and the telescopic action of the manipulator claw is flexible. However, it is found that the adjustment block on the manipulator is worn. It is disassembled and observed that the adjustment block is mainly used to clamp the tool handle. After re repair and processing, try again, The offset disappears at the spindle position. The main cause of this fault is the large impact of the manipulator and frequent tool change, resulting in the loosening and wear of the clamping claw, as shown in Figure 3.
Contact: Ada Li
Tel: +86 17722440307
WhatsApp: +86 17722440307
E-mail: Ada@honscn.com
Add: 4F, No. 41 Huangdang Road, Luowuwei Industrial, Dalang Street, Longhua, Shenzhen, 518109, China