1.ID modeling;
A.ID sketch ............
B.ID outline drawing ............
C.MD outline drawing ............
2. Modeling;
A. Information inspection ............
B. Draw a basic shape ............
C. Preliminary disassembly of painted parts ............
1.ID modeling;
The design process of a complete product begins with ID modeling. After receiving the customer's original data (which can be a sketch or a text description), ID starts the shape design. ID Draw the outline plan that meets the customer's requirements, submit it to the customer for confirmation, and gradually modify it until the customer agrees; There are also some companies that draw several drafts by ID, and the customer chooses one, and ID draws an outline on the basis of this draft; The type of outline drawing can be 2D engineering drawing with necessary projection view; It can also be a JPG color map; Either way, the overall size should be indicated generally, and the surface technology should be as complete as possible according to the actual situation; After the outline map is determined, the next job is structural design engineer (MD);
By the way, if the customer's creativity is relatively complete, some companies will directly use MD to make outline drawings without ID;
If the product has clear requirements for the internal structure, some companies will participate in the adjustment of the shape while drawing the shape map with ID;
MD starts to start. First, check the data. The data of ID to MD can be JPG color map, and MD will import the color map into PROE and trace the lines. The information given by ID to MD can also be IGES line drawing, and MD will import IGES line drawing to PROE for higher accuracy; In addition, if it is a mobile phone design, the customer needs to provide a complete electronic scheme, or even a physical object;
2。 Build a moving stage,
Taking my working method as an example, MD draws a basic shape according to the information provided by ID (I am used to using BASE as the file name); The base is like the cornerstone of a building, and all surface components should be built on the surface of the base.
So the 3D base and ID of MD are different. ID focuses on modeling, regardless of draft angle. MD should not only do the drawing angle in BASE, but also know the assembly relationship of each part. It is suggested that colleagues in the structure department communicate in a small scale, exchange views and avoid detours.
The specific method is to import the file provided by ID first, respect the design intent of ID, and cannot be changed at will;
Line drawing, PROE is a parametric design tool, and the purpose of line drawing is to facilitate measurement and modification;
When drawing a surface, the surface should be as consistent as possible with the solid, which is also the basis of subsequent disassembly. If possible, try to integrate it into a closed surface, or repair it by surface modeling.
After the foundation is completed, please confirm with ID. This step should not omit the second step of the construction phase. Take the surface based on BASE, and disassemble each part. The disassembly method is based on the outline drawing of ID.
Face/bottom shell, the battery door only needs a preliminary shape, and the thin shell can be removed inside;
I make MP3, MP4/bottom shell thickness 1.50mm, mobile phone/bottom shell thickness 2.00mm, wall clock/bottom shell thickness 2.50mm, waterproof product surface/bottom shell thickness 3.00mm；;
In addition, I have also made medical devices with a thickness of 4.00mm on the surface/bottom shell, and the guests insisted on it again and again out of concern for strength, which is actually 3.00 mm.
Very safe. If the wall thickness is too thick, it is easy to shrink, and it is also easy to produce internal stress and cause deformation. I'm worried about my lack of strength.
It can be solved by pulling the reinforcing ribs inward, and the effect is far better than simply increasing the wall thickness;
The third step in the construction stage is to make an assembly drawing, introduce the disassembled parts according to the assembly order, and select the reference center.
Overlapping arrangement; Put in electronic solutions, such as LCD, LED, battery, COB. . . When each component is introduced into the assembly drawing, some components are made into an assembly as required, and then the assembly is introduced into the assembly drawing.
For example, to make a flip phone, there are only two components in the general assembly drawing, the upper cover is a component and the lower cover is a component. The upper cover assembly is divided into shell assembly, shell assembly and LCD assembly. The lower cover assembly is divided into C-shell assembly, D-shell assembly, motherboard assembly and battery assembly. You can also divide it down.
3. Initial modeling stage: divided into three aspects;
Answer: ODM is designed by the modeling engineer; Can be selected by customers or independently developed.
B: Customers provide design materials, such as IGS documents (mostly) or pictures (OEM).
C: change from the original appearance; Can be selected by customers or independently developed.
4. The fourth step of the construction phase, location check, requires the placement of common components.
For example, the position of LCD can be thought as follows: the thickness of lens is 1.50mm, the thickness of double-sided adhesive is 0.20mm, and the local thinning thickness of the face shell is 0.60mm, so the distance from LCD to the outermost is 2.30mm；; There is no interference between components, and there is a distance requirement. For example, when designing an electric wave clock, in order to ensure the receiving effect, the distance between the receiving antenna and the battery is required to be more than 20 mm. For the convenience of design, it is best to set the elements in the assembly drawing in different colors to distinguish them. After all the big parts are installed in place, I still suggest that, for the sake of safety, please confirm the appearance effect again;
5 talk about the independent design method, which is the above scheme a:
A, modeling engineers make sludge models or use 3D software to simulate modeling and make foaming physical models, and after various evaluations (determine what materials to use according to UL or EN standards, check and determine the air inlet and outlet structure, air outlet structure, air outlet window form, switch and winding button mechanism, air duct mechanism, etc. After the modeling scheme is determined, this stage will take about one to two months.
B, design the structure: make the internal structure of the thin shell (the sludge model needs to be copied and the surface needs to be made) obtained above; Design of vacuum chamber, design of vacuum chamber door lock; Design of intake filter and motor room; During this period, we should often discuss with modeling engineers, suppliers and mold engineers, such as the conflict between appearance and structure, whether the choice of materials and structure conflicts with the mold and so on. And we can do some related analysis with software.
C, after the above design is qualified, make scaffolding. After the scaffold board is completed, relevant tests shall be conducted according to safety requirements, including performance, assembly, structure, noise, drop and other tests, and design changes shall be made after comparison with design input.
D, mold! After 40~50 days (during this period, we should always communicate with the mold factory to ensure the accuracy of structural dimensions and grasp the progress in time. ) The mold is finished. Make samples and send them to customers for testing. After information feedback, it can be mass-produced after the second and third design changes.
6 the actual situation of our company:
A. customers give their own ideas, JPG image format or scanned hand-drawn drawings.
B, tracing lines in AutiCAD to generate views, cross sections and dimensions of products at various angles.
C. Draw the basic shape in three-dimensional software such as PRO/E, and then gradually improve the details and split the parts.
D, handing the three-dimensional block to a mold factory for processing.
The modeling is completed, just as the frame of the building has been set up. Now we can rely on the framework to improve each layer from bottom to top. Taking an electronic product as an example, the structural design process of a complete product is introduced.
The design of this electronic product, my approach is:
Lens structure -LCD structure-luminous structure-column structure-waterproof structure-key structure.
PCB structure-battery structure-auxiliary structure-dimensional inspection-hand board follow-up-mold follow-up.
Lens structure:
General lens requirements 1.5mm, if the conditions are insufficient, it can be 1.0mm, and the mobile phone lens can be thinner; (Note: If screen printing is needed, make the screen printing surface as flat as possible; The mobile phone lens is influenced by the shape, and both sides are curved surfaces, which can be transferred in the mold. ) lenses should be fixed, usually with double-sided tape, and a space of 0. 15-0.20mm should be reserved, and some lenses can be fastened; If there is a waterproof requirement, the lens can also be welded by ultrasonic wave, but the ultrasonic line should be reserved in the structure;
LCD structure:
For electronic products, LCD (liquid crystal display) is like her eyes, and its structure directly affects the display effect; LCD is usually made into a square, and can be cut into corners and made into polygons if necessary; The thickness of LCD is usually 2.70mm, and the ultra-thin LCD is also1.70 mm; ; A single LCD needs to be connected to the motherboard (hereinafter referred to as COB) to display. Common connection methods are conductive adhesive strips and hot-pressing and heat-sealing connectors. Among them, the conductive adhesive strip should have a preloading amount, which is generally 10%- 15%. If the preload is too small, the LCD will be missing, and if the preload is too large, the LCD will be green. Hot-pressing and heat-sealing joints do not need preloading, but the cost is high. The connection needs hot-pressing die cutting machine, and the joint foot needs precision hot-pressing die cutting machine. The LCD and the lens can't be directly attached, and it is easy to produce waterline when attached. There are also cases where the LCD is directly fixed on the lens. I opened a square groove in the VA display area of the lens, leaving a gap of 0.30mm; ; Usually, the lens is external, the LCD is internal, and there is a face shell in the middle, and the local glue of the face shell is at least 0.50mm；; The lens of LCD should also be kept clean, usually in a closed structure. In digital products, liquid crystals are often made into components and wrapped in iron frames or plastic frames. There are PCB and IC inside, and the signal is output through the flexible PCB with plug at the end, which is convenient for disassembly and assembly. In digital products, there is a gap of 0.30mm between the LCD module and the face shell, which can also be separated by a sponge of 0.50mm or dustproof.
Luminous structure:
Commonly used light sources are lamps, LEDs and EL sheets, and commonly used light-emitting structures are reflector, reflector and EL bracket. Lamps are scattered light and are usually used with reflectors. The reflector is pot-shaped and sprayed with white oil. Different colors of lights can get red, green and blue color effects. Lamps can also be used with reflectors. The light path of LED is relatively concentrated, and it is usually used with reflector. In order to effectively improve the brightness, the thickness of the reflector is preferably above 2.0. The reflector can be made into a wedge shape (cross section), and the back is sprayed with white oil, so that the light enters from the side and can be evenly reflected to the front. If you want to improve the brightness, you can also spray white oil on the side (except the light inlet) to reduce the loss of light. LED itself has five colors: red, orange, green, blue and purple. The luminous effect of EL sheet is relatively uniform, which can be used with EL bracket and EL conductive adhesive strip. Available in green and blue, it is usually made in the same shape and size as the LCD display area. When using EL film, it needs fire cow to supply power, so the cost is high.
The reflective structure of notebook computer is quite special. I have seen a reflective structure of a notebook computer, in which a round organic light-emitting diode is used to shoot a long glass rod, and the glass rod enters from the side of the reflector after being evenly irradiated, thus obtaining quite good backlight effect. There are also some small bumps with circular structure on the back of the reflector, where the light diffuses, just like a small light source. The small bumps are sparse near the glass rod and dense away from the glass rod, so that the brightness of the whole reflector is the same. In addition, projection clock directly projects the time onto the wall, and its structure is to use bright red LED round lamp to illuminate the anti-white liquid crystal to get the time display, and then the time is magnified and projected onto the wall through two convex lenses. As for sharpness, adjust the distance between two convex lenses. Finally, LCD with light emitting structure is usually translucent or super transparent.
Column structure and waterproof structure:
Clearance column is a threaded column connecting the face shell and the bottom shell, and its structure directly affects the assembly effect and reliability of the whole machine. The customs clearance can be done at the end of structural design, but the planning should be considered clearly when modeling. For example, because a product is waterproof, a waterproof ring is set around the customs clearance column, so the position of the customs clearance column must be determined first; The design of customs clearance column should first consider the force of the whole machine. Generally, the tooth depth is required to be at least 3 turns, and the chip clearance in the hole is above 0.30 mm.. Where there are clear columns, the outer wall is thick, which is easy to cause shrinkage and affect the appearance. Usually the thickness of thin wall is reduced to1.00 mm; At the bottom of the screw hole; Usually, the clearance column of wall clock uses 2.60mm screws, with an inner diameter of 2.20mm and an outer diameter of 5.00mm, and the screw spacing is wider; Small electronic products usually use 2.00mm screws, with an inner diameter of 1.60mm and an outer diameter of 4.00 mm. The screw spacing depends on the needs, and no screws can be seen in appearance as much as possible. If necessary, it can be hidden in the battery door or under the detachable parts, or it can be buckled to replace the screw on one side. The electric clock should try to avoid the screws in the direction of the antenna axis, and also try to avoid the screws near the antenna of the mobile phone; For example, a waterproof clock uses 1.70mm screws, with an inner diameter of 1.40mm and an outer diameter of 3.60mm. Because it is waterproof, it uses stainless steel screws. There used to be an MP3 player with only one 1.40mm screw. The inner diameter of the screw was 1. 10mm, and the outer diameter of the screw was 2.60mm The other side was buckled, and the screw was hidden under the lens. Another flip phone has two 1.40mm screws under the rotating shaft position, which are used together with a copper nut. The copper nut has an outer diameter of 2.50mm and is pressed into a hole of 2.30mm after heating. At the other end, two dead buttons with a depth of 1.00mm are made, and 0.50mm movable buttons are used on both sides of shell A and shell B for easy disassembly; If space permits, some rocket feet can be pulled around the long screws, which can not only improve the stress, but also make the glue flow smoothly during injection molding; This product needs waterproof. Waterproof ring can be used for the whole machine. What about waterproof keys? Or the piston structure is made of waterproof ring, which is waterproof and movable. Use a metal needle to make a circle of grooves and fix the waterproof ring to one side. One end of the metal needle has a button cap and the other end has a socket piece on the PCB. This function is realized when the button socket piece is pressed. In order to ensure the waterproof effect, the gap between the metal needle and the pinhole should be 0.05-0. 10mm, and the pinhole should be smooth when waterproof oil is used; The cross section of the main waterproof ring of a product is a right circle with a diameter of 1.20mm, and the preloading amount is more than 30% and the compression amount is 0.40mm, so the design width of the waterproof groove is 1.20mm, and the depth is 0.80mm, which is larger than the cross section diameter of the waterproof ring. When it is used with waterproof oil, it will not fall out when it is put into the waterproof tank. In addition, in order to ensure the waterproof effect, the clearance column screws are outside the waterproof ring, and the distance between the clearance columns cannot exceed 20.00mm；; Some waterproof products have a button on one side of the battery door and a screw on the other side. The compression of 0.40mm is obviously not enough. What if it is at least 0.60? People have a brilliant idea to make the cross section into the shape of quick-acting meatballs, with two semicircles up and down and a straight middle end, which can increase the compression; By the way, if the waterproof requirement is not high, the lens of this machine can also be directly bonded with double-sided tape, and the bonding surface is smooth, so that foreign objects can be blown clean when bonding;
Some waterproof products have a button on one side of the battery door and a screw on the other side. The compression of 0.40mm is obviously not enough. What if it is at least 0.60? People have a brilliant idea to make the cross section into the shape of quick-acting meatballs, with two semicircles up and down and a straight middle end, which can increase the compression; The purpose of increasing vertical position is to increase compressibility and make it easier to be waterproof;
(Attached figure, the compression of 0.60mm is waterproof compared with the compression of 0.40mm, and it doesn't matter if it is slightly deformed from the shell. )
Key structure:
Commonly used buttons include snap button, rubber button and mechanical button, which can be selected according to space size, travel requirements and feel requirements;
Wozi piece has a short stroke, generally 0.20mm~0.50mm, and is made of metal, with good reliability and small occupied space. The child with feet can be installed through the through hole on the PCB. This product uses the child with feet. The mobile phone keyboard is also made of nested pieces, but it has no feet, so it needs to be positioned accurately when it is bonded;
The rubber button has a long stroke, generally 1.00mm, and there are also 0.50 mm rubber buttons, which are not as reliable as the nest pieces and occupy a large space. Its advantage is that the keys feel good. Telephone commonly used rubber buttons, connected into a whole, easy to install;
Mechanical keys, in fact, the performance of the metal socket is similar to that of the socket, but there is an auxiliary mechanism, and the feel of the keys is easier to adjust to the best state than the socket. MP3 and MP4 generally use mechanical keys, and can also be made into five-digit keys;
By the way, the push cover can be pushed mechanically, and the blocking feeling is difficult to control. Insufficient assembly clearance may affect the blocking feeling. I prefer to push with plastic, and the gear position is well controlled, generally 2.00mm, and the minimum can be1.50 mm;
One point that needs special attention is the key structure. If you press it, you should be able to rebound smoothly. This bad situation often happens on rubber keys with long strokes. The countermeasure is to increase the depth of the focus. For example, for a rubber key with a stroke of 1.00mm, the plastic key cap on it is more than 1.00mm higher than the surface of the shell. If the plastic keycap is not more than 1.00mm higher than the surface of the shell, MP3 and MP4 usually make the key 0.30mm higher than the surface of the shell. When digital products are operated, users will pay more attention to the surface of keys, so designers will achieve the ultimate in the surface effect of keys. The commonly used key surface treatment processes are electroplating, which can make a matte surface effect on the mold, highlight the edge and make a knife carving effect;
PCB structure:
PCB is the carrier to which electronic components are attached. Generally, the thickness of push plate of small electronic products is 0.80mm, and the thickness of main control board (hereinafter referred to as COB) is1.00 mm; ; For general large electronic products (such as wall clocks), the thickness of push plate is 1.00 mm, and the thickness of COB is1.20 ~1.60 mm; If the limited PCB area is not enough to meet the wiring requirements, jumpers can be added, and a single panel can be changed into a double panel, and a double panel can be changed into a multilayer board (such as the motherboard of a computer); Electronic components on PCB can be divided into common components and patch components according to their sizes, such as coils, fire bulls, large capacitors and so on. Patch components, such as patch resistors, patch capacitors and patch IC; The gap between the reflector and COB of small electronic products (such as electronic clocks) should be reserved for ic, because it is best for ic to be close to the spacing position of LCD to facilitate wiring. After bonding and sealing, the IC needs a height of at least1.50 mm. As mentioned above, the cross section of the reflector is wedge-shaped, which is also beneficial to the placement of IC; If the LCD and COB are connected by conductive adhesive strips, the screw spacing for pressing the conductive adhesive strips should not exceed 15.00mm to avoid missing drawings; Key positions on PCB need to be emphasized. If possible, try to be close to the screw post and the slot, and add support points on the opposite side if necessary;
Power sockets and earphone sockets commonly used in digital products also need to be stressed, and supporting bones can be added on the other side of the sockets on the PCB; Wiring on PCB requires conditions and time. My approach is to provide a preliminary board cutting diagram to the electronic engineer for trial laying when modeling, so as to ensure that the PCB area will not be too different from the needs. In the middle process of structural design, the placement of large components and sensitive components should also be communicated and coordinated with electronic engineers (for example, when making Bluetooth headphones, the antenna is usually placed at the end near the mouth); After all the structures are completed, a formal board cutting drawing will be made. When the electronic engineer lays the board, the structural party is making the hand board. After the hand board is finished, the PCB board is almost back, just to install the functional model. Solving the problem first will save a lot of time; As far as the structural design process of this small electronic product is concerned, PCB is only half done, followed by battery structure; (Bluetooth headset adopts mechanical buttons, so that the buttons are 0.30mm higher than the surface of the shell, and the battery of Bluetooth headset is directly attached to the PCB, no problem, but the bottom shell should be slightly located on the side of the lithium battery as far as possible, which is beneficial; There should be a gap (generally 0.50mm) in the thickness direction to prevent the lithium battery from expanding after charging. Product structure designer refers to a senior engineer who is engaged in product specification, function and appearance design according to the requirements of customers. Reasonably design the internal and external structure of products to ensure that products can be developed with the shortest time, the lowest cost and the highest quality.
The main skills required by product structure designers include:
1, basic knowledge of mechanical design;
2. Familiar with the design of plastic parts, sheet metal parts and die castings; That is, manufacturing-oriented design; Ensure simple parts design, high quality, few defects and low manufacturing cost, and at the same time, the corresponding die structure is simple and easy to manufacture and process.
3. Skillfully master the assembly design skills of products; That is, assembly-oriented design; The assembly of products is as important as the manufacture of products. The assembly of products should make the assembly process simple, the assembly efficiency high, the assembly defects few, the assembly cost low and the assembly quality high. Commonly used assembly design criteria include reducing the number of parts, simplifying product structure, standardizing parts, modularizing products, designing stable base, designing guiding features, positioning parts before fixing, error-proof design, ergonomics design and so on. For detailed guidance, please refer to the Product Design Guide for Manufacturing and Assembly published by Machinery Industry Press. The book also includes guidelines for plastic parts design, sheet metal parts design, die casting design and tolerance analysis. Mastering these design criteria skillfully can ensure product design in the shortest time, the lowest cost and the highest quality.
4, master the knowledge of tolerance analysis; Able to use tolerance analysis to optimize product design quality and solve practical problems encountered in product development;
5. Familiar with related materials, molds and surface treatment technologies;
6. Have the ability to analyze and solve problems; There are bound to be many problems in product development, and the ability to analyze and solve problems is very important.
7. Familiar with product development process, especially manufacturing and assembly process. A good product development process can help product structural engineers reduce design changes, shorten product development time and improve product development quality;
8. Be familiar with relevant product testing requirements, such as emi, esd, safety and reliability, and design products to meet these requirements;
9. Familiar with relevant product industry standards;
10, knowledge of 3d and 2d software. Commonly used 3D softwares include pro/e, ug, solidworks, catia, etc. , and can master one of them skillfully. The commonly used 2d software is autocad；;
1 1, good innovative spirit; You can learn the relevant theoretical knowledge of triz.
12, team spirit; The success of product development is inseparable from team cooperation. It is impossible for a product structural engineer to fully grasp the knowledge of product manufacturing, assembly and testing. Product engineers should be able to improve the quality of product development by cooperating with manufacturing engineers, assembly engineers and test engineers.