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Sheet metal product manufacturing steps(sheet metal processing)

Jun 17,21

Sheet metal product manufacturing steps(sheet metal processing)


1. Sheet metal processing method:
(1) Non-die processing: through digital punching, laser cutting, shearing machine, folding machine, rivet machine and other equipment on the sheet metal processing process, generally used for sample production or small batch production, high cost.
(2) mold processing: through the fixed mold, the sheet metal processing, generally have the blanking mold, molding mold, mainly used for mass production, the cost is low.
2, sheet metal processing technology
Feeding: several punching, laser cutting, shearing machine
Forming - bending, stretching, punching: bending machine, punch, etc
Other processing: pressure riveting, tapping, etc
welding
Connection mode of sheet metal
Surface treatment: powder spraying, electroplating, wire drawing, screen printing, etc
1, sheet metal processing technology - blanking
The blanking method of sheet metal is mainly several punching, laser cutting, plate shearing machine, mold blanking, etc., the number of punching is currently commonly used, laser cutting is mostly used for proofing stage, the processing cost is high, mold blanking is mostly used for mass processing.
The following we mainly to the number of punching to introduce sheet metal blanking.
The number of punch, also called turret punch, can be used for blanking, punching, stretching holes, reinforcing bars, etc., and its processing accuracy can reach +/-0.1mm.The plate thickness that can be processed by digital punching is:
Cold-rolled plate, hot-rolled plate ≤3.0mm
Aluminum plate is 4.0 mm or less
Stainless steel plate ≤2.0mm
(1) punching has small size requirements.The small size of punching is related to the shape of the hole, the mechanical properties of the material and the thickness of the material.(as shown below)

(2)number of punch hole spacing and hole margin.The small distance between the punching edge and the shape of the parts is limited by the different shapes of the parts and the holes. When the punching edge is uneven with the edge of the shape of the parts, the small distance should not be less than the material thickness T;When parallel, should not be less than 1.5T.(as shown below)

(3)When stretching the hole, the small distance from the edge of the stretching hole is 3T, the small distance between two stretching holes is 6T, and the small safe distance from the bending edge (inside) of the stretching hole is 3T+R (T is the thickness of sheet metal, and R is the rounded corner of bending).

(3)when the stretching bending parts and the drawing parts are punched, a certain distance should be maintained between the hole wall and the straight wall.(as shown below)

2, sheet metal processing technology - molding
Sheet metal forming is mainly sheet metal bending, stretching.
(1) sheet metal bending
(2) the basic principles of bending processing sequence: from the inside to the outside for bending, from small to large for bending, bending special shape first, then bending general shape, before the process of forming after the subsequent process does not have an impact or interference.


② Small bending radius of bending parts:
When the material is bent, the outer layer is stretched and the inner layer is compressed in the rounded area.When the thickness of the material is constant, the smaller the inner R is, the more serious the stretching and compression of the material will be.When the tensile stress of the outer fillet exceeds the ultimate strength of the material, cracks and breaks will occur. Therefore, the structural design of the curved parts should avoid too small bending fillet radius.The small bending radius of the materials commonly used by the company is shown in the table below.

(2) sheet metal drawing
The stretching of sheet metal is mainly completed by numerical punching or general punching, which requires various stretching punches or molds.The shape of the drawing part should be as simple and symmetrical as possible, and the drawing should be formed in one time as far as possible.Where parts are to be drawn more than once, surface marks that may be formed during the drawing process should be allowed.Under assembly requirements, a certain inclination of the stretched side wall should be allowed.
(3) Sheet metal other molding:
(1) reinforcing bars -- reinforcing bars are pressed on the plate metal parts to help increase the rigidity of the structure.

(2) blinds -- blinds are usually used for various cover shells or chassis for ventilation and heat dissipation.
③ Hole flanging (tensile hole) -- used for machining threads or improving the rigidity of the hole.
3, sheet metal processing technology - welding
In the design of sheet metal welding structure, should implement the "symmetrical layout of welds and solder joints, and avoid intersection, aggregation, overlap, secondary welds and solder joints can be interrupted, the main weld, solder joints should be connected.The commonly used welding in sheet metal is arc welding, resistance welding, etc.
(1) Arc welding
There should be enough welding space between the sheet metal, the welding gap should be 0.5-0.8mm, and the weld should be uniform and smooth.

4, sheet metal processing technology - connection mode
This paper mainly introduces the connection mode of sheet metal in the process of processing, mainly including rivet riveting, welding (as described above), suction hole riveting, TOX riveting.
(1) rivet riveting: this kind of rivet is often called pull nails, the two plates are riveted together through the pull nails, called pull riveting.Common riveting shapes are shown in the figure below:

(2) Pumping hole riveting:
One of the parts is a suction hole, the other part is a sink hole, through the riveting die so that it becomes a non-detachable connection.Superiority: the suction hole and the countersunk hole with its own positioning function.The riveting strength is high and the efficiency of the riveting through the die is also high.

(3) TOX riveting:
The connector is pressed into the die through a simple punch.Under further pressure, make the material inside the die to "flow". The result is a no edges, no burr and circular points, and will not affect the corrosion resistance, even to the surface coating or spray paint layer board anticorrosive also can keep the original features, because the deformation of coating and paint layer is also along with the flow.The material is pushed to the sides and into the plate on the side of the die to form the TOX connecting dots.As shown on the following page:

5, sheet metal processing technology - surface treatment
The treatment of sheet metal surface can play the role of anticorrosion protection and decoration.The common surface treatment of sheet metal is: powder spraying, electrogalvanizing, hot dip zinc, surface oxidation, surface drawing, screen printing, etc.
The oil, rust and welding slag on the surface of sheet metal should be removed before surface treatment.
(1) powder spraying: there are two kinds of liquid paint and powder paint on the surface of sheet metal. We commonly use powder paint.Through powder spraying, electrostatic adsorption, high temperature baking and other ways, the surface of the sheet metal is sprayed with a layer of various colors of paint, used to beautify the appearance, and can increase the corrosion resistance of the material.Is a common way of surface treatment.
(2) electric galvanizing, hot dip zinc: sheet metal surface galvanizing is a commonly used surface anti-corrosion treatment method, and can play a certain role in beautifying the appearance.Galvanizing can be divided into galvanizing and hot dip zinc.The appearance of galvanizing is relatively bright and flat, and the galvanizing layer is thin, which is more commonly used.Hot dip zinc layer is thicker, and can produce zinc - iron alloy layer, corrosion resistance is stronger than electric zinc.
(3) surface oxidation: here mainly introduces the surface anodizing of aluminum and aluminum alloy.Aluminum and aluminum alloy surface anodizing can be oxidized into a variety of colors, play a protective role and have a good decorative role.At the same time, the anodic oxidation film can be produced on the surface of the material. The anodic oxidation film has higher hardness and wear resistance, and good electrical insulation and thermal insulation.
(4) surface drawing: put the material in the wire drawing machine between the top and the bottom of the wheel, the sand belt attached to the wheel, driven by the motor, let the material through the upper and lower sand belt, pull a trace on the surface of the material, according to the different sand belt, the trace thickness is different, the main function is to beautify the appearance.Generally, it is aluminum that is considered to use the brushed surface treatment.
(5) screen printing: the process of screen printing on the surface of materials, there are generally two ways of flat screen printing and pad printing. The flat screen printing is mainly used on the general plane, but if there is a deep pit, it needs to use pad printing.Screen printing requires a screen mould.