Introduction
Welding jigs play an important role in the production and quality control of car body. The design and production of car body welding jig should rely on the automobile manufacturing process, general quality requirements and technological properties of engineering materials. The design accuracy, welding process conditions and environmental quality of the welding jig must meet the requirements of the technological process of automobile welding process. The jig should be designed to be simple and maintainable, and the welding process should be consistent and meet the requirements of the car body welding process.
General Quality Requirements
First, the car body welding jig should be durable and structurally stable. The material selection and association of the car body welding jig should consider the maintenance and transportation needs, and consider the product properties and comprehensive properties of the materials. The welding jig should consider the overall size of the product, the overall design of the structure, the combination of different materials (see Fig.1), the connection points and other factors. All the dimensions in the design should meet the requirements of the car body welding process.
Second, the welding jig should be easy to use and maintain, and should be equipped with an operation and maintenance manual. When designing the welding jig, all kinds of holding devices, support devices, positioning devices and organizational devices should be reasonably arranged. The connection structures should have sufficient stiffness and strength to ensure the positioning accuracy and reliable operation of the jig.
Third, the welding jig should meet the requirements of the welding process and the welding environment, and should provide a safe welding environment and stable welding performance. The welding jig should also consider heat dissipation and fire prevention design measures. In the connection of welding jigs and welding table, it should consider the problem of heat dissipation and insulation; in welding jig support structure, the problems of thermal expansion, shrinkage, tempering, sealing and adjacent parts should also be considered.
Fourth, the welding jig should be economical and affordable, with sufficient strength and stiffness to enable the product to produce the required welds in the process. The jig should be able to maintain the positioning accuracy for a long time and not interfere with the welding process.
Finally, the cost of the jig should be considered in the design, the design cycle should be short and the production should be high. The car body welding jig should meet the requirements of the welding process, ensure the weld quality, reduce the production cost and improve the production efficiency. It should also be able to meet the requirements of different types of products and different production Lots.
Design of Car Body Welding Jig
When designing the car body welding jig, the size and organization of the cutting parts should be designed according to the shape of the car body. The design should consider the positioning accuracy of the parts, the shape of the parts, the need to consider the stability of the parts, and the need to consider the stiffness and strength of the fixtures (Fig.2). The parts should be designed to facilitate processing and reduce costs. In terms of design accuracy, the design should consider the relationship between processing accuracy and welding accuracy. According to the different characteristics of different parts, the positioning accuracy of the parts should be determined. In order to improve the production capacity and reduce the processing time, the design should reduce the number of clamping devices, reduce the parts used, and connect the clamping devices as far as possible.
The welding grinding easy to cause deform parts should be designed with enough stiffness and strength to ensure that the parts can be welded in the specified position (Fig.3). The two sides of the welding jig should be symmetrically arranged, and special structural characteristics should be considered for parts with asymmetrical structural characteristics. The jig should consider the connection between the parts and the parts with different sizes. In order to reduce the deformation of the welding jig, the welding jig should have adequate stiffness and strength to meet the requirements of the welding process. The welding jig should adopt the design of easy exchange parts, easy maintenance and simple repair, and attach sufficient attention to the requirements of lubrication of the moving parts.
The design of car body welding jig should take into account the connection of welding table and car body, the problem of heat dissipation and insulation, the problems of thermal expansion and shrinkage, etc., to ensure that the welding jig works reliably and stably. The welding jig should be equipped with safety devices to ensure the safety of personnel and equipment. The welding jig should also consider heat dissipation and fire prevention.
Conclusion
The design of welding jig is the key to the welding quality of car body. A reasonable welding jig should be designed to meet the requirements of automobile welding process and production process, so as to ensure the quality of car body welding, reduce the production cost and improve the production efficiency. At the same time, it should pay attention to the reasonable design of connection of welding table and welding jig, thermal expansion and shrinkage of welding jig, heat dissipation and insulation, etc., and properly adjust and repair the welding jig so as to ensure the stability and accuracy of the welding jig.
