Sheet Metal Processing

Detailed description

Sheet metal processing selection - Lide Electric. One-stop chassis shell customization, with advanced CNC equipment, sheet metal processing customized drawings, on-time delivery, and honest management. Welcome to come in for consultation! Sheet metal processing is a sheet metal

technician The key technology that needs to be mastered is also an important process in the forming of sheet metal products. Sheet metal processing includes traditional cutting, blanking, bending and forming methods and process parameters, as well as various cold stamping mold structures and process parameters, various equipment working principles and control methods, and also includes new stamping technology and new processes. Part metal sheet processing is called sheet metal processing.


2. Key points of each sheet metal process
1. Number of punches
1.1 Processing limit
1.11 Processing limit of plate specifications
1.111 Cold plate
length: 0-2500
Width: 0-1250
Thickness: 0.8-2.5 (less than 1mm, welding is very difficult, larger than 2.5mm Punching cannot be processed (logarithmic punching loss is large), and only laser cutting, wire cutting, punching (requires Cape punching die), milling, drilling, etc. 1.112 Copper row length: 0-1500 Width: 0-600


Thickness : 1-4mm, if it exceeds 4mm, use shearing machine for blanking and punching (requires Cape punching die head) 1.1.2 Hole position limit 1.1.2.1 The distance between holes and the distance between holes and edges needs to be considered: A , Overcome the flanging effect; B. Avoid punching the material, the harder the material, the greater the distance required; C. Avoid excessive deformation, the denser the holes, the greater the deformation after processing. The difference between material holes and holes, holes and The distance between edges cold plate, copper, brass, aluminum 0.5T stainless steel 0.8T


Note: T is the plate thickness.
1.1.2.2
Minimum aperture
material
Minimum aperture
cold plate, copper, brass, aluminum

1T
stainless steel

1.5T
Note: For square holes, the minimum side length is not less than 1.2mm. Square holes that are too small can easily cause mold damage.

2.
For bending, the main issues that need to be considered by design engineers are as follows:
A. Bending interference;
B. Minimum bending: no less than 4 times the plate thickness. Lower than this limit may cause processing difficulty to be greatly increased. Even if it cannot be processed, you should communicate with the process engineer at this time.
C. Deformation of the hole caused by bending: The hole is too close to the bending line and may be pulled and deformed by the mold.
Since bending often needs to be determined based on actual conditions, maintaining necessary communication with process engineers can greatly improve design efficiency. 3. When possible,


Puchong should try to be standardized and consistent to reduce mold opening costs and shorten the proofing cycle. 4. When the fitter countersinks the hole: it should be noted that the plate thickness is not less than the height of the countersunk screw head, otherwise the screw head will be higher than the plate, resulting in unstable fixation. 5. Pressure riveting 5.1 When the plate thickness is less than 1mm, the riveting parts may easily fall off. In this case, expansion riveting or electric welding after pressure riveting can be used to ensure the fastening strength. 5.2 The relationship between riveting screws and plate thickness: Plate thickness 1.0-2.0mm 2.0-2.5mm >2.5mm Screw specifications M5 and below M6 M8 5.3 If the riveting parts are too close to the edge, there will be two consequences:

A. After riveting, the edge of the plate will be deformed (the edge will bulge), and the hole position will shift 0.1-0.5mm to the edge;
B. The riveting position is too close to the folded edge, which will cause the riveting upper mold to be unable to press down: Press riveting The distance from the outer edge of the head to the folded edge: not less than 3mm.


5.4 When riveting the inside of U-shaped bent parts, consideration should be given to whether the riveting lower mold can be attached to the workpiece. If other workpieces with relatively small internal spaces need to be riveted on the inside, this issue should be taken into consideration.


5.5 The specifications of the rivet parts should be as uniform as possible to facilitate the supplier's ordering, shorten the sampling cycle, and also reduce the probability of errors in the rivet parts.


6. Welding
6.1 If a workpiece with a relatively small internal space needs to be welded on the inside, consideration should be given to how to extend the welding gun.
6.2 When the plate thickness is ≤1mm, shrinkage holes or burn-through are likely to occur after welding, and the deformation caused by welding is large.
6.3 The welding of copper, aluminum and other materials is difficult and requires high technical level of welding workers.


7. Spray coating


Spray coating is mainly divided into the following three types (each includes indoor and outdoor):
Flat gloss: It can be subdivided into matt, flat gloss, and high gloss. The thickness of the spray coating is about 60-90 μm, and it is about 90-120 μm after spraying.
Sand texture: It can be subdivided into fine sand texture and coarse sand texture. The thickness of the sprayed layer is about 50-80μm, and it is about 80-110μm after back-spraying.
Orange grain: It can be subdivided into small orange grain and large orange grain. The thickness of the sprayed layer is about 90-120μm, and it is about 120-150μm after spraying.


The thickness of the spray coating at locations where powder is likely to accumulate on the workpiece will exceed the above thickness.


7.1 Flat gloss: Advantages: beautiful appearance, good screen printing effect; disadvantages: high spraying cost, high spraying rework rate, easy to scratch, and scratches on the outer surface cannot be repaired, among which high-gloss spraying is the most difficult.
Avoid using flat lights when possible, especially for large chassis, as they are prone to bumps during transportation.
7.2 Sand texture: Advantages: Not easy to scratch, spraying cost is the lowest among the three; Disadvantages: Oil stains on the surface are not easy to remove, and the silk screen printing effect is not as good as flat or orange texture.
7.3 Orange grain: Advantages: not easy to scratch, good screen printing effect, easy to remove oil stains on the surface, spraying cost is slightly higher than sand grain, but much lower than flat grain. Disadvantages: The aesthetics are slightly lower than plain light.
7.4 The spraying colors should be as uniform as possible and use the colors of the company’s mainstream products to facilitate suppliers’ ordering of powder.
7.5 Try to use only one spray color for a product to reduce spraying costs (processing hours are greatly increased when spraying multiple colors) and also reduce the probability of supplier spraying errors.
7.6 The use of silver powder should be avoided. Silver powder is a silver-containing compound. The price of the powder is twice that of ordinary powder. It is also difficult to spray and prone to defective products.


3. Introduction to sheet metal materials
1. Cold plate
definition: The abbreviation of ordinary carbon structural steel cold-rolled steel plate. The hot plate becomes a cold plate after being cold rolled and annealed.
Features: Good surface quality, high dimensional accuracy, good machining performance, high surface quality and strong spray adhesion due to annealing treatment. Commonly used specifications are 0.5-2.5mm, and materials larger than 2.5mm are difficult to buy.
Common specifications: 2500*1250
Cost: lower,
materials are easy to buy.


2. Hot plate
definition: the abbreviation of hot-rolled steel plate.
Features: Because it is not annealed, the machining performance is not good. The internal crystallization is uneven and the surface is prone to cracking and rusting. For inverter sheet metal, hot plates are used when the plate thickness is greater than 2.5mm.
Cost: Low
Common specifications: 3000*1250
Materials are easy to buy.


3. Galvanized plate
definition: cold plate with a layer of zinc on the surface, generally refers to hot-dip galvanized plate. Galvanizing is a low-cost, cost-effective means of preventing corrosion. About half of the zinc produced in the world is used in the galvanizing process. If the surface is not scratched, the anti-corrosion period can exceed ten years.
Features: Good machining performance, care should be taken to protect the surface during processing to avoid scratches. Generally, it is not sprayed. The adhesion of spraying is not as good as that of cold plate (no rust removal before spraying to avoid damaging the protective layer).
Cost: Slightly higher than cold plate
Common specifications: 2500*1250
Materials are easy to buy.


4.
Definition of electrolytic plate: Also called electrolytic galvanized plate, it uses electrolysis to form a uniform and dense galvanized layer on the surface of the steel plate.
Features: The machining performance is good, and the thin plate is not easy to weld. When processing, attention should be paid to protecting the surface to avoid scratches. Generally, spraying is not performed. Spraying sometimes produces pinholes (no rust removal is required before spraying to avoid damaging the protective layer). Compared with galvanized sheets, it has better anti-corrosion performance.
Common specifications: 2500*1250
Cost: High
materials are not easy to buy, and there are too few suppliers to sell them.


5.
Definition of aluminum-zinc coated plate: 55% aluminum, 43.4% zinc and 1.6% silicon are plated onto the surface of the steel plate using a hot-dip process.
Features: The machining performance is good. During processing, care should be taken to protect the surface to avoid scratches. Generally, spraying is not performed. Compared with galvanized sheets, it has better anti-corrosion performance, is not easily oxidized and discolored at high temperatures, and has a beautiful appearance. The surface patterns are divided into large flowers, medium flowers and small flowers.


Common specifications: 2500*1250
Cost: High
materials are not easy to buy, and there are too few suppliers to sell them.


6. Copper materials
are mainly divided into red copper (also known as red copper), brass and bronze. At present, Guixi, Jiangxi Province is the largest copper smelting base in Asia, with high quality. Our company specifies Guixi Copper when purchasing copper materials.


7. Insulation materials
7.1 Bakelite: It has high hardness, is difficult to machine, and is easy to break. When designing, it should be considered that the hole position should not be too close to the side. The edge should be larger than 2mm. If the hole is too close to the side, the processing speed will be reduced and it is easy to produce cracks. Scrap. Currently, the quality of bakelite materials recommended by your company, Taiwan Xindai, is the best. However, the maximum thickness of Taiwan Xindai's bakelite is 50±1.5mm. Bakelite materials exceeding 50mm can only use domestic materials (which need to pass the insulation performance test).
7.2 PVC: The hardness is between bakelite and nylon. It is easy to process. The material can be tapped. The cost is equivalent to the price of domestic bakelite and lower than that of Xindai bakelite.
7.3 Nylon: The material is soft and difficult to machine. The cost is equivalent to that of Xindai Bakelite, so it is not recommended.


4. Suggestions on sheet metal design
1. Universal fasteners
2. Avoid opening special molds as the first choice when designing, and try to find alternative solutions. If the batch size is large, it is not too late to open the mold after mass production. .
3. It is recommended to communicate more with the supplier’s process engineers.


5. How to estimate the sheet metal processing cycle


. Estimation of the processing cycle of new products:
Project deployment: 3 days below 55KW; above 55KW: 3-5
days. Machining: 4 days.
Spraying and assembly: 2 days


. 6. Introduction to NCT mold