The automobile industry is a pillar industry in the global manufacturing industry. With the development of science and technology and the continuous growth of market demand, the frequency of car-renewal is accelerating. Among them, the important factor affecting car-renewal is the update of the function and appearance of the car cover. Automobile anti-collision beams are an important part of automobile panels and are important devices for automobiles to absorb collision energy and occupy an important position in automobile production. Since the forming process of automobile beams is relatively complicated, it is a complex shaping process with large deflection and large deformation. Therefore, the fluidity and strengthening of the metal under stress should be fully considered in the mold design, and the possible metal cracks and cracks should be considered. Therefore, it is necessary to explore the application of CAE technology in the design of anti-collision beam stamping die, to optimize and adjust the stamping process and die design of automobile anti-collision beam, to improve the qualification rate of parts and shorten the mold design and production time. The purpose of improving production efficiency.

Stamping process design of automobile anti-collision beam

The concept of the stamping process

The so-called stamping process is a method of processing a workpiece with a certain shape by separating or deforming a mold under pressure based on metal plastic deformation. The workpiece processed by the stamping method is called a stamping part, and the stamping process is important in automobile manufacturing. Compared with other parts, covering parts have the characteristics of the complex structure, large size and area, difficult molding, and high-quality requirements. Therefore, stamping and forming methods are commonly used to process such parts.

Classification of the stamping process

In stamping production, stamping processing methods can be divided into two major types of processes, namely separation and forming processes. The separation process is mainly to separate the workpiece and the blank along the determined contour, to achieve the desired effect. The forming process refers to the plastic deformation of the blank under the premise of ensuring the integrity of the blank, to obtain the anti-collision beam of the expected size and shape. Divided according to the stamping process, the stamping process can be divided into blanking, punching, cutting, bending, stretching, flanging, trimming, and shaping.

The content and steps of processo de estampagem design

Due to the complex shape of the automobile anti-collision beam, the large structural size, the high-quality requirements, and the high rigidity requirements, it is difficult to form at one time, and it needs to go through multiple processes to obtain the parts that meet the requirements. When designing the stamping process of automobile anti-collision beams, various factors need to be comprehensively considered. Not only should it meet the production efficiency requirements of automobile manufacturers at this stage, but also should combine the process production cost and economic factors, and design the production process plan of the anti-collision beam stamping Review. The steps include analysis of stamping parts, formulation of stamping process plan, determination of stamping process plan, selection of die type and structure, and selection of stamping equipment.

Stamping process

The automobile anti-collision beam is located on the inner side of the bumper. It is usually punched into a U-shaped groove from cold-rolled steel plate and connected with the automobile frame longitudinal beam. It is an important device for absorbing and protecting the vehicle’s impact ability and has good formability. The product can meet the performance requirements of its anti-collision. At the same time, the product is a non-appearance part with high-performance requirements. Therefore, in the design of the anti-collision beam, it must be considered that the anti-collision beam should have a certain rigidity after forming.

Take an automobile anti-collision beam as an example. The material of the anti-collision beam is B510L, the length is about 1.2m, the width is about 0.4m, the blank thickness is 1.5mm, and the drawing depth is 90mm. Automobile anti-collision beams should be produced based on meeting the design requirements of customers. Therefore, the appearance, thinning rate, sufficient degree of deformation, and punching position of the anti-collision beam should meet the design requirements. At the same time, the finished parts should also meet the hardness and strength requirements, and be free of wrinkles and cracks. Besides, due to the irregular appearance of the part and the complicated deformation structure, it is a typical large-size and complicated deep drawing part. Therefore, the main points of the stamping process include: deep drawing, not easy to be fully formed, and a large drawing force is required. Need to use mechanical equipment with large drawing force, large stroke and uniform pressure distribution; when designing the stamping process, the size of the waste and the complexity of the mold structure should be considered, and the outer edge of the part can be trimmed or side trimmed first, And finally reshape; there is a regular circular hole above the car’s anti-collision beam with a diameter of 37mm, which can combine punching and trimming procedures to reduce the number of processing techniques.

Blank analysis

B510L is a common stamping material for automobile beams, with good cold forming performance and strength performance. This material has the characteristics of high quality, high surface finish, good welding performance, and easy to apply oil and paint. The blank is analyzed by Dynaform software, and the blank size is 1200mm long, 340mm wide, and 1.5mm thick.

Drawing process design

In the drawing design, the working coordinate system of each process should be determined first, namely the stamping direction and digital model reference point. The determination of the stamping direction is a key process of the design work, and its correctness directly affects the shape of the blank and the quality of the subsequent drawing process. The stamping process should be determined by comprehensive consideration of multiple factors: the stamping direction should not cause negative angles, to ensure that the stamping can be formed into the expected spatial shape, as far as possible to minimize the drawing height difference, and thereby reduce the fluidity and deformation of the metal. Quality problems caused by uniformity. At the beginning of drawing, the contact state between the punch and the sheet should be checked to avoid the relative movement of the punch and the sheet, which would affect the stamping efficiency and improve the surface quality of the part.

Secondly, when designing the pressing surface, to obtain qualified stamping parts, it is necessary to ensure that the sub-fabric is smooth and flat to prevent the sheet from wrinkling during the pressing process. At the same time, the design of the pressing surface should be as simple as possible, flat and inclined, to avoid large lateral force in a certain direction.

Trimming and punching process design

Due to the large size of automobile anti-collision beams, if a one-time forming process is adopted, the waste formed by punching may not be discharged in time. Therefore, when designing the punching of the anti-collision measurement, adopt Two processes are designed, namely side trimming and punching and side trimming. Determine the trimming line according to the requirements, adopt a combination of vertical trimming and oblique wedge trimming, punch out round holes while trimming. After determining the trimming line, the trimming defense line should be determined, and the direction perpendicular to the surface of the anti-collision beam should be taken as far as possible. When the conditions are not suitable, the oblique wedge process can be used for trimming. When using this oblique wedge method, it should be ensured that the angle between the trimming direction and the profile surface should be less than 15°, and not more than 30°. After determining the trimming direction, the subsequent mold design process should be fully considered, and the mold structure should be as simple as possible to avoid unnecessary troubles to the subsequent process.

Shaping process design

The shaping process is the last step of the entire stamping process. After the above process, the shape of the blank is close to the shape of the finished part, but it needs to be reshaped locally. Therefore, in the process design of the anti-collision beam, it must be reshaped. Processing to correct and check the shape of the anti-collision beam. Because the profile of the anti-collision beam is relatively complex, and the radius of some rounded corners is small, defects such as cracks and damage are prone to occur during shaping. Therefore, according to the actual situation, the deepened rounded corners can be increased during shaping to facilitate Deep drawing operation. In the shaping process, in order to meet the design requirements of the final shape of the anti-collision beam part, the fillet should be processed in the shaping process to adjust the final shape of the part, improve the processing dimensional accuracy of the part, and meet the design requirements of the part.

Design of stamping die for automobile anti-collision beam

In the production of automobile anti-collision beams, the mold is a necessary component of the stamping process. According to the different functions and processes, the automobile anti-collision beam molds can be divided into deep drawing molds, trimming punching molds, trimming molds, shaping molds, and drawing molds. Deep mold is the basis of subsequent molds, limited to the length of the article, this article mainly takes the drawing mold of automobile anti-collision beam as an example, and introduces the design method of automobile anti-collision beam mold from the aspects of punch, die, positioning device, etc.

Punch design

The design of the punch of the automobile anti-collision beam includes the production of the punch of the anti-collision beam and the production of the profile part. When designing the punch, it should be stretched upward from the anti-collision crossbeam to form a rectangular parallelepiped, the convex model surface should be corrected, and the weight reduction holes and guide plate installation positions should be designed to obtain the deep drawing punch body. In the design of the profile part, the manufacturing steps are the same as the design steps of the punch, and the profile is cut by stretching the parting line to form the final profile.

Concave mold design

To achieve the purpose of weight reduction, when making the deep drawing die of the automobile anti-collision beam, a rectangular parallelepiped can be drawn up from the middle profile, and the die can be trimmed in the direction of the drawing parting line to obtain the profile. Carry out Boolean subtraction with the rectangular parallelepiped of the die to obtain the frame of the anti-collision beam drawing die. On this basis, the frame is hollowed out. At the same time, some ribs are added inside the cavity to obtain the cavity of the cavity.

Design of press core

When designing the blanking core mold, first create a rectangular parallelepiped of a certain size, determine the outer edge profile of the stretched surface, and use the rectangular parallelepiped and Boolean subtraction operations to operate the rectangular parallelepiped to create the blanking core top device, and the top device, The top plate of the lower die and the ejector pin will finally get the design plan of the pressing core.

Positioning device design

The positioning device is a positioning device on the anti-collision beam, used to fix the upper and lower molds of the drawing mold. When designing the positioning device, the height of the device should consider the height of the pressing surface to ensure that the positioning block is placed perpendicular to the sheet line, in order to ensure that the positioning block is placed relatively perpendicular to the sheet line. When designing the positioning device, factors such as the height of the pressing surface should be considered.

Conclusion

Automobile anti-collision beam is an important part of automobile covering parts, and it is also an important device for absorbing collision energy during an automobile collision. It occupies an important position in automobile devices. In the process of stamping process research and mold design of vehicle anti-collision beams, detailed process plans should be formulated, with the aid of CAE technology, the drawing process should be analyzed and studied, and process parameters should be optimized. At the same time, the stamping die is designed with the help of UG software to simplify the stamping process and die design process, improve the efficiency of die design, and ensure the quality of anti-collision beams.