Specification and quality of design and manufacture of dimensional flexible welding fixture. In general, the design of welding fixtures for auto parts has the following characteristics: 　　 (1) The fixture should have sufficient strength and rigidity. The fixture has to withstand a variety of forces when it is put into use in production, so the fixture should have sufficient strength and rigidity; 　　 (2) the reliability of clamping. Do not destroy the positioning position of the workpiece during clamping and ensure that the product shape and size meet the requirements of the drawing. It can neither allow the workpiece to loosen and slip, nor make the restraint of the workpiece too large and produce a larger restraint stress; 　　 (3) flexibility of the welding operation. The use of fixtures should ensure enough space for assembly and welding, so that the operator has a good view and operating environment, and the whole process of welding production is in a stable working state; 　　 (4) facilitates the loading and unloading of weldments. During operation, it should be considered that the product can be smoothly removed from the fixture after assembly tack welding or welding, and the product should not be damaged when it is turned over or lifted; 　　 (5) good manufacturability. The designed fixture should be easy to manufacture, install and operate, and easy to inspect, repair and replace vulnerable parts. The design should also consider factors such as the existing clamping power source, hoisting capacity and installation site in the workshop to reduce the cost of fixture manufacturing.