Stiffeners are commonly used in the manufacturing industry. In the automobile, in addition to have the special request appearance surface, most automobile body sheet metal will design the stiffener.

Two situations should be considered when designing the pressing surface: one is that one part of the pressing surface is the flange surface of the drawing part. The shape of the pressing surface of this kind of deep drawing part is determined, generally it does not change its shape, even if it is partially modified to improve the drawing forming conditions, it should be reshaped and corrected in the subsequent process; the other situation is that the pressing surface belongs to the supplementary part of the process. In the latter case, the design of pressing surface is mainly to ensure good drawing forming conditions. The design principle of pressing surface is:

Metal stretch stamping is a kind of forming processing method to produce plastic deformation or separation of sheet, strip, tube and profile by using press and die, so as to obtain the required shape and size of workpiece (stamping part). Stamping and forging belong to plastic processing (or pressure processing), collectively known as forging. The billets for stamping are mainly hot-rolled and cold-rolled steel plates and strips.

Stamping in automobile industry. Mainly in deep drawing. In China, this part is mainly concentrated in automobile factories, tractor factories, aircraft manufacturers and other large-scale independent stamping and drawing factories. Automobile parts stamping in automobile industry. It is mainly formed by punching and shearing. Many of the enterprises in this department are owned by standard parts factories and independent stamping factories. At present, there are many such small factories near some automobile factories or tractor factories. Electrical parts stamping plant. This kind of factory is a new industry, developing with the development of electrical appliances. The factories in this department are mainly in the south. Daily necessities stamping factory. Making some handicrafts, tableware, etc. these factories have made great progress in recent years.

Stamping part is a kind of production technology which can directly deform the sheet metal in the die with the help of the power of conventional or special stamping equipment, so as to obtain certain shape, size and performance of product parts. Sheet metal, die and equipment are the three elements of stamping. Stamping is a method of metal cold deformation. Therefore, it is called cold stamping or sheet metal stamping, or stamping for short. It is one of the main methods of metal plastic processing (or pressure processing), and also belongs to material forming engineering technology.

There are a lot of poor quality problems in the process of stamping production. Raw materials, process, mold and other factors are the important reasons for the poor quality. In the process of production and stamping forming, it is necessary to determine the causes of quality defects, and put forward corresponding practical improvement measures to formulate corresponding preventive measures, so as to solve and improve the quality defects, avoid the recurrence of corresponding quality problems, and continuously improve the quality of stamping parts.

Stamping is mainly classified by process, which can be divided into separation process and forming process. The purpose of the separation process is to separate the stamping parts from the sheet along a certain contour line and ensure the quality requirements of the separation section. The purpose of forming process is to make the sheet metal plastic deformation without breaking the blank, and to make the required shape and size of the workpiece. In actual production, it is often a variety of processes applied to a workpiece. Punching, bending, shearing, stretching, bulging, spinning and straightening are the main punching separation processes.

A large number of cold stamping processes have been used in the production of automotive stamping parts, which are suitable for the needs of many varieties and large-scale production of automotive stamping parts industry. In medium and heavy-duty vehicles, most of the covering parts, such as body outer panel, and some load-bearing and supporting parts, such as frame, carriage and other auto parts are automobile stamping parts. The steel used for cold stamping is mainly steel plate and steel strip, accounting for 72.6% of the total steel consumption of the vehicle. The relationship between cold stamping materials and the production of automobile stamping parts is very close. The quality of automobile sheet metal materials not only determines the performance of the product, but also directly affects the process design of automobile stamping parts, and affects the quality, cost, service life and production organization of the product. Therefore, reasonable selection is necessary Using materials is an important and complex work.

Metal cutting is a kind of machining method that uses the cutter to cut the metal blank layer by layer and make the workpiece get the required shape, size and surface roughness. Metal cutting includes two methods of benchwork and machining - benchwork is a machining method that workers use hand tools to cut. It is flexible and convenient to operate and widely used in assembly and repair. Machining is accomplished by means of machine tools, including turning, planing, milling, drilling and grinding.

Daily necessities, such as aluminum pot, lunch box, washbasin, etc., are made by cold stamping. For example, to make a lunch box, you first need to cut a rectangular blank with four rounded corners (known as "blanking") and then use a punch to press the blank into a die to form (known as "drawing"). In the drawing process, the flat sheet becomes a box shape, with four sides vertically bent upward, and the materials at four corners gather and wrinkle can be seen.

Sand mold is usually used to make iron castings. The raw material of sand mold is mainly sand, which is mixed with binder and water. The sand mold material must have a certain bonding strength, so as to be molded into the required shape and be able to resist the erosion of hot metal without collapse. In order to form a cavity in the sand mold which is consistent with the shape of the casting, the wood mold must be made first. The volume of hot molten iron will be reduced after cooling. Therefore, the size of the wood mold needs to be increased according to the shrinkage based on the original size of the casting, and the surface to be machined should be thickened accordingly.

Whether the parts are combined into parts or the parts are combined into the whole vehicle, the mutual cooperation relationship specified in the design drawings must be met to make the parts or the whole vehicle achieve the predetermined performance. For example, when assembling the transmission to the clutch housing, the centerline of the transmission input shaft must be aligned with the centerline of the engine crankshaft. This centering method is not adjusted by the fitter (fitter) during assembly, but is guaranteed by the design and manufacturing.

Modified plastics are based on general plastics and engineering plastics. Through adding modifiers, filling, blending, strengthening and other methods, they improve the flame retardancy, strength, impact resistance and toughness of plastic products. Modified plastics are widely used in automobile industry because of their unique properties that other materials do not possess. With the increasing requirements of automobile lightweight, energy saving and environmental protection, the amount of automobile modified plastics is increasing year by year. In October 2016, China Society of automotive engineering released the energy saving and new energy vehicle technology roadmap. The roadmap points out that by 2020, 2025 and 2030, the vehicle mass needs to be reduced by 10%, 20% and 35% respectively compared with 2015. Modified plastics for automobile mainly include polypropylene, polyurethane, ABS materials, HDPE, polycarbonate, nylon, etc. According to the data, China's total plastic production increased from nearly 18 million tons in 2004 to nearly 80 million tons in 2016, and the modification rate increased from 8% to 19%. However, compared with 40% of the world's modified plastics used in the automobile industry, only about 10% in China. In late November 2016, it is expected that in the next few years, the automotive industry will become a fast growing area of China's modified plastic consumption. It is estimated that China's annual output of automobiles will reach 30 million in 2021. According to the conservative usage of each 300 kg automobile modified plastic, the compound annual growth rate of automobile modified plastic industry will exceed 26% in the next five years. In the next few years, the upgrading of polyolefin and modified plastics products in petrochemical and coal chemical industry needs to focus on the automotive plastics market.

Automobile anti-collision beam is by no means the fundamental factor to ensure the safety of the people in the car, but it is meaningful to the safety. Its role is reflected in the low-speed collision, and in the high-speed accident, automobile parts anti-collision beam is powerless. Compared with the body longitudinal beam and stiffener, the strength of the crash beam is not worth mentioning. What really saves your life at this time is to try to keep the cockpit intact. Therefore, we should treat the anti-collision beam rationally.

The body structure of each car must go through the quality inspection after the production line. Generally, the laser and scanning methods are used to check the stability of each welding point and metal structure. For example, the 360 automatic body measurement technology (auto CMM) we use is to verify the quality of the car body after it is offline.

The methods to inspect the cracks of the parts include magnetic flaw detection, fluorescent flaw detection and aerosol flaw detection. For the cast parts such as water-cooled cylinder block and cylinder head, cracks are often found by water pressure test. For some hidden cracks on the surface of shaft parts, the method of immersion knocking can also be used to find cracks.

The inspection of automobile parts is an important process in the process of automobile overhaul, which will directly affect the quality and cost of automobile repair. Through inspection, automobile parts can be divided into three categories: available, to be repaired and scrapped.

The welding method of stamping parts is generally determined by their volume, welding position and structure of welding stamping parts, generally including overhead welding, flat welding, vertical welding and horizontal welding. Among the four welding methods, the complicated one of Zui is overhead welding. In the process of overhead welding, Zui short arc and small diameter electrode are used, so it is very difficult.

Measurement method of hardware stamping parts: for hole measurement of hardware stamping parts, the small value of Zui is taken according to the measurement method of go no go gauge. Generally, the small value of Zui can be recorded when measuring with caliper (excluding the small value, such as the error caused by measurement error), (not excluding the special situation) the large value of Zui recorded has no practical significance with the average value, and it is significant for the measurement of hole diameter in all directions Small differences should be recorded in the roundness of the geometric tolerance, not in the hole diameter.

Metal stamping is a kind of technology that uses punch and die to deform or fracture iron, aluminum, copper and other plates and dissimilar materials to achieve a certain shape and size. Metal stamping is sometimes called sheet forming, but it is slightly different. The so-called plate forming refers to the use of plates, thin-walled tubes, thin profiles, etc. as raw materials.