Technical characteristics and production mode of high-speed precision stamping parts

1. Technical characteristics of high-speed precision stamping parts

There are a wide variety of high-speed precision stamping parts, with large production capacity, high precision, and complex shapes. Thin plate materials are used and the materials are diverse. The main types of high-speed precision stamping parts have the following technical characteristics.

The stator and rotor cores are important components of a motor, and their quality directly affects the technical performance of the motor. The traditional manufacturing process for the stator and rotor iron cores of electric motors involves using a general punch to punch out the stator and rotor punched pieces (loose pieces), which are then aligned and then riveted, buckled, argon arc welded, and other methods to make the iron core. For AC motor rotor cores, it is also necessary to manually twist them to create grooves. The stepper motor requires uniform magnetic properties and thickness direction of the stator and rotor cores, and a certain angle of rotation is required between the stator core and the rotor core punching plate. If made using traditional methods, the efficiency is low and the accuracy is difficult to meet the technical requirements. With the continuous development of industrial production technology, high-speed stamping multi-station progressive dies have been widely used in the fields of motors, electrical appliances, and other technologies to manufacture automatic laminated structural iron cores, such as the stator and rotor iron cores of various micro motors, as well as the iron cores of mountain shaped, U-shaped, and small transformers. The stator and rotor cores can also be equipped with twisted inclined slots, and there is a large angle rotating riveting structure between the punching plates. Compared with ordinary stamping dies, multi-station progressive dies have the advantages of high stamping accuracy, high production efficiency, long service life, good consistency in the size accuracy of the stamped iron core, easy automation, and suitability for mass production. They are the direction of precision mold development in the micro motor industry.

Electronic stamping parts have the most types and the most complex structures. Electronic stamping parts generally have high accuracy requirements, while also requiring precise and uniform thickness of stamping materials, smooth and clean surfaces, without spots, scars, scratches, surface cracks, etc. The yield strength of the materials is uniform, without obvious directionality, with high uniform elongation and low work hardening.

Heat exchanger fins refer to the metal sheets used for heat transfer in a heat exchange device. Increasing the heat exchange surface area of the heat exchange device can improve heat exchange efficiency. The annual production of heat exchanger fins reaches hundreds of millions of pieces, and the material is usually 0.08-0.20mm thick aluminum foil, so high-speed progressive die production must be used.

Semiconductor lead frames are the carriers of semiconductor chips, playing an interface role between semiconductor devices and printed circuit boards (PCBs). Its prominent characteristics are: surface quality, shape accuracy, shape and position accuracy, accumulated error, appearance characteristics, and other requirements, which are the highest among all stamping parts. Especially the shape of its inner leads is basically like a crab foot shaped thin and long cantilever, which is different from the conventional stamping process.

There are various types of electrical connectors with a wide range of applications, including stamping parts with various forms, which generally have the following characteristics.

(1) High reliability, due to the electrical signal connection between subsystems, it is required to maintain reliability under harsh conditions such as impact, vibration, stress relaxation, environmental corrosion, etc. Electroplating treatment is generally carried out to ensure corrosion resistance.

(2) High precision requirements are required for conventional civilian product connector stamping parts. Generally, the punching accuracy is within ± 0.03mm, and the bending accuracy is within ± 0.05mm. However, for high-level punching accuracy requirements, ± 0.01mm is required, and the bending accuracy is within ± 0.02mm.

Micro forming stamping parts mainly include micro drawing, incremental forming, micro punching, and micro bending methods for thin plates. Compared with traditional stamping processes, although the process is the same, micro stamping is not a simple reduction in the shape of traditional stamping.

As the size of formed parts decreases, micro stamping has the following characteristics.

1) The ratio of surface area to volume increases, thereby affecting temperature conditions.

2) The smaller the size of the part, the greater the influence of adhesion force and surface tension between the tool and mold.

3) The influence of grain size is significant and is no longer seen as a homogeneous continuum like traditional forming.

4) When the width and thickness of the product are equivalent, a high strain rate can affect the plasticity and microstructure of the material, especially the grain size and typical workpiece size.

5) The smaller the size of the part, the smaller the proportion of the closed lubrication pit area to the total lubrication area, and the more difficult it is to store lubricant on the surface of the workpiece.

Hardware stamping parts are widely used in various fields that we are familiar with, including electronic devices, automotive parts, decorative materials, instruments and meters, etc. Hardware stamping parts have the characteristics of thin, uniform, light, small, and strong.

2. Production mode of high-speed precision stamping parts

High speed precision stamping parts are mainly mass-produced using high-speed precision press production lines and multi-station carbide progressive dies, which also include progressive dies composed of punching, drawing, bending, flanging, riveting and other processes. The materials are mostly rolled strips, which are automatically placed by the automatic feeding rack and generally need to be leveled by a leveling machine. The materials that have been leveled are automatically fed by a high-speed press attached feeder. To improve stamping performance, the surface of the material needs to be soaked or sprayed with stamping oil. Choosing stamping oil also requires evaluating the needs of the subsequent process. The parts are generally automatically packaged by the reel of the receiving machine, with interlayer paper or plastic film added to the parts, or directly fed into the collector by the conveyor belt. Some stamped parts require post-processing, such as cleaning, electroplating, etc. The vast majority of high-speed precision stamping parts are produced using single machine automation, while some complex parts are produced using multi machine automatic production lines.