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Selection of automotive welding fixtures

2025-08-01

When selecting automotive welding fixtures, it is essential to comprehensively consider factors such as welding task requirements, material properties, structural design, precision requirements, drive mechanisms, cost, and production schedules. The following is a detailed analysis:
1. Define the welding tasks and requirements
Welding type: Different welding tasks require different types of fixtures, such as spot welding fixtures, TIG welding fixtures, laser welding fixtures, and robotic welding fixtures.
Part Characteristics: Consider factors such as part shape, size, weight, weld seam arrangement, and technical requirements, as these factors determine the complexity of the fixture structure. For example, large thin-walled welded parts, which are prone to deformation, require more complex fixtures to enhance rigidity.
2. Select Appropriate Materials
Welding fixtures must possess high heat resistance, corrosion resistance, and wear resistance, making material selection critical.
Common materials include high-speed steel, tungsten steel, hard alloys, ceramics, and synthetic materials. For example, protective plate materials can be made of chromium-zirconium copper, with an effective plate thickness between 10mm and 12mm; locating block materials can be made of MC nylon to prevent the locating blocks from scratching the outer panels.
III. Consider the fixture's structural design
Shape and strength: Fixtures should be easy to operate and use, and have sufficient strength and stability.
Handle Design: A reasonable handle design can enhance operational comfort and reduce operator fatigue.
Openness: The fixture structure should be open to facilitate worker operation and access to the welding area. If necessary, portions of the fixture frame that impair openness can be removed to improve the fixture's openness.
Standardization and Specification: Standardized and specified locating components should be used whenever possible to facilitate replacement and maintenance, and to allow adjustment within a certain range to ensure locating accuracy and adjustment of the welded part's shrinkage.
4. Consider the fixture's precision requirements
Locating Precision: The precision requirements for the fixture should be determined based on the specific welding task. For example, the positional tolerance of the main locating pin should be controlled within ±0.1mm, and the assembly tolerance of the locating surface should be controlled within ±0.2mm.
Stability: Ensuring the stability and precision of the fixture is critical for different welding tasks.
5. Consider the fixture's drive method
Non-driven fixtures: These consist only of locating blocks, locating pins, and other locating components, requiring no power source, and are suitable for simple welding tasks.
Manual fixtures: The power source comes from manual force, utilizing the self-locking principle of a four-bar linkage mechanism for clamping, suitable for small-batch production or maintenance operations.
Pneumatic fixtures: The power source comes from industrial compressed air, with a high degree of automation, saving production time on assembly lines, and widely applied in automotive welding processes.
6. Consider cost and production volume
Single-piece production: It is advisable to determine universal fixtures that can be used for both this product and another product to reduce production costs.
Mass production: It is advisable to select or design specialized fixtures, such as assembly jigs or welding jigs, to improve production efficiency and product quality.
Batch production: Depending on the batch size, it is further divided into large-batch, medium-batch, and small-batch production. Products in small-batch production have low repeatability, so it is advisable to determine fixtures with higher versatility; for medium-batch or large-batch production, if assembly line operations are adopted, specialized fixtures can be determined or designed to reduce auxiliary time.