Precision hardware stamping parts are high-precision metal components processed through stamping technology, widely used in numerous fields such as electronics, automobiles, aerospace, and medical devices. They have the advantages of high dimensional accuracy, good surface quality, high production efficiency, and low cost, occupying an important position in modern industrial production. This article will elaborate on the classification and structural design points of precision hardware stamping parts in detail.
I. Classification of Precision Hardware Stamping Parts
1. Classification by Stamping Process
1.1 Blanking Parts
Blanking parts are stamping parts obtained by separating materials using a stamping die, including blanking parts and punching parts. Blanking parts are parts with a certain shape and size punched out from sheet metal, such as gaskets and blades; punching parts are various shaped holes punched in sheet metal, such as bolt holes and heat dissipation holes. The main characteristics of blanking parts are clear contours and high dimensional accuracy, and their quality mainly depends on the accuracy of the stamping die and blanking process parameters.
1.2 Bending Parts
Bending parts are parts formed by bending flat blanks or semi-finished blanks along a straight line into a certain angle and shape, such as right-angle brackets and U-shaped grooves. During the processing of bending parts, the material undergoes plastic deformation, and springback may occur at the bending position, affecting the dimensional accuracy of the parts. Therefore, when designing bending parts, it is necessary to consider the springback amount and take corresponding compensation measures in the die design.
1.3 Drawing Parts
Drawing parts are various open hollow parts made from flat blanks through a drawing die, such as cylindrical shells and box-shaped parts. The forming process of drawing parts is relatively complex, and defects such as wrinkling and cracking are prone to occur. To ensure the quality of drawing parts, it is necessary to reasonably determine process parameters such as the drawing coefficient and die gap, and perform multiple drawing and intermediate annealing treatments.
1.4 Forming Parts
Forming parts are parts processed by stamping processes such as bulging, necking, flaring, and flanging. Bulging is to obtain the required convex or concave shape through local plastic deformation of the blank by the die; necking and flaring are to reduce or expand the end diameter of pipes or hollow parts; flanging is to turn the edge of the blank or the edge of the hole into a vertical edge. Forming parts have various shapes and can meet different usage requirements.
2. Classification by Application
2.1 Electronic and Electrical Stamping Parts
These stamping parts are mainly used in electronic equipment and electrical products, such as connectors, terminals, heat sinks, and motor cores. They usually have the characteristics of small size, high precision, and strict requirements on surface quality, and also have certain requirements on the conductivity and thermal conductivity of materials.
2.2 Automotive Stamping Parts
The automotive industry is an important application field for precision hardware stamping parts, including body stamping parts (such as doors, hoods, chassis parts, etc.), engine stamping parts (such as cylinder gaskets, oil pans, etc.), and chassis stamping parts (such as shock absorber accessories, brake system parts, etc.). Automotive stamping parts are large in size, complex in shape, and have high requirements on strength and rigidity.
2.3 Aerospace Stamping Parts
The aerospace field has extremely high requirements on the quality and performance of stamping parts, such as aircraft structural parts, engine parts, and spacecraft connectors. These stamping parts are usually made of high-strength, high-temperature-resistant materials, with the characteristics of high precision, high reliability, and light weight.
2.4 Medical Device Stamping Parts
Medical device stamping parts are mainly used in various medical equipment and instruments, such as surgical instrument accessories, medical instrument housings, and infusion set connectors. They have strict requirements on the biocompatibility and corrosion resistance of materials, and at the same time, the dimensional accuracy and surface quality must meet relevant standards.
II. Structural Design of Precision Hardware Stamping Parts
1. Material Selection
Material selection is an important part of the structural design of precision hardware stamping parts, which needs to be comprehensively considered according to the usage requirements of the parts, the characteristics of the stamping process, and the cost. Common stamping materials include low-carbon steel, stainless steel, aluminum alloys, and copper alloys. Low-carbon steel has good plasticity and stamping performance, and is low in price, suitable for manufacturing stamping parts for general purposes; stainless steel has excellent corrosion resistance and strength, suitable for environments with high requirements; aluminum alloys and copper alloys have the characteristics of light weight and good conductivity, suitable for electronics, aerospace and other fields.
When selecting materials, it is also necessary to consider the thickness and mechanical properties of the materials. The thickness of the material should be determined according to the strength and rigidity requirements of the part, and at the same time, it should be compatible with the stamping process. The mechanical properties of the material (such as yield strength, tensile strength, elongation, etc.) will affect the plastic deformation and forming quality during the stamping process, and suitable materials should be selected according to the specific stamping process.
2. Structural Shape Design
2.1 Simplifying the Shape
To reduce the difficulty and cost of stamping, the structural shape of precision hardware stamping parts should be as simplified as possible, avoiding complex curves and surfaces. On the premise of meeting the usage requirements, a symmetrical structure should be adopted to reduce the complexity of stamping processes and dies. For example, for bending parts, simple right-angle bending should be used as much as possible, avoiding multi-directional bending and complex polygonal bending.
2.2 Avoiding Sharp Corners and Sudden Changes
In the structural design of parts, sharp corners and sudden changes in size should be avoided to reduce stress concentration during stamping and prevent parts from cracking. Fillet transitions can be used, and the size of the fillet radius should be determined according to the thickness of the material and the stamping process. Generally speaking, the fillet radius should not be too small; for materials with good plasticity such as low-carbon steel, the fillet radius can be 0.5-1 times the material thickness.
2.3 Reasonable Arrangement of Reinforcing Ribs
For some thin-plate stamping parts, to improve their strength and rigidity, reinforcing ribs can be reasonably arranged. The shape and size of the reinforcing ribs should be determined according to the stress conditions and structural characteristics of the parts, and usually, strip or wave shapes can be adopted. The arrangement of reinforcing ribs can increase the local thickness of the material, improve the deformation resistance of the parts, and at the same time, will not significantly increase the weight of the parts.
3. Dimensional Accuracy Design
The dimensional accuracy of precision hardware stamping parts should be determined according to the usage requirements; excessively high accuracy will increase production costs and difficulties. In design, the key dimensions and tolerance requirements of the parts should be clarified and marked clearly on the drawings. For blanking parts, their dimensional accuracy mainly depends on the accuracy of the stamping die, which can generally reach IT10-IT14; for bending parts and drawing parts, due to factors such as springback, the dimensional accuracy is relatively low, generally IT12-IT16.
To ensure the dimensional accuracy of parts, the characteristics of the stamping process should be considered in the structural design. For example, for parts that require multiple stamping, the stamping processes should be reasonably arranged to avoid the accumulation of dimensional errors between processes. At the same time, corresponding measures should be taken in the die design, such as setting positioning devices and adjusting die gaps, to improve the dimensional accuracy of parts.
4. Process Design
4.1 Facilitating Stamping Processing
The structural design of parts should facilitate stamping processing, reducing the number of stamping processes and dies. For example, for parts that need punching and blanking, a composite die can be used to complete them at one time, improving production efficiency. For bending parts, the bending radius should meet the requirements to avoid material cracking during bending.
4.2 Considering Die Manufacturing and Maintenance
The structural design of parts should also consider the manufacturing and maintenance of the die. Complex structures will increase the manufacturing difficulty and cost of the die, and are also not conducive to the maintenance and repair of the die. Therefore, in design, the die structure should be as simple as possible to facilitate processing and assembly.
4.3 Conducive to Material Utilization
In structural design, the utilization rate of materials should be considered to reduce the generation of waste. The utilization rate of materials can be improved and production costs can be reduced by optimizing the arrangement of parts and adopting nested stamping methods.
III. Conclusion
There are many classifications of precision hardware stamping parts, and different types of stamping parts have different characteristics and application fields. In structural design, it is necessary to comprehensively consider factors such as material selection, structural shape, dimensional accuracy, and processability to ensure that the parts can meet the usage requirements, while having high production efficiency and low cost. With the continuous development of industrial technology, the requirements for precision hardware stamping parts are getting higher and higher, and structural design needs to be continuously innovated and optimized to adapt to new application scenarios and technical challenges.
