The size tips of fixture

The size tips of fixture

In the welding workshop, we position the workpiece in the correct position and clamp it through the clamp to ensure the correct assembly relationship between the body parts. From stamping parts welding to sub assembly, then to BIW assembly welding, finally in the adjustment line to complete the assembly of four doors, two covers and fender, in order to ensure the smooth completion of welding and assembly process, fixture is essential.

Air conditioning ventilation duct – front section – (7)

Welding workshop fixture classification?

Welding fixture: it is mainly used in the welding station of the welding workshop to position and clamp the parts to ensure the smooth welding.

Assembly fixture: mainly used in the adjustment line to complete the assembly of four doors, two covers and fender.

Dimension measurement items in fixture

The base plate, also known as base plate, is the installation base plate of the clamping unit on the fixture. The assembly and measurement datum of the fixture are all on the base plate, which has flatness requirements.

Fixture measurement benchmark: in order to test whether the assembly accuracy and machining accuracy of the fixture can meet the requirements, three coordinate measurement is needed after the fixture is assembled. The surface of the fixture base plate is equipped with measuring balls to establish the coordinate system or shapes that can create the reference system (generally > = 4), and marked with the corresponding coordinate theoretical value.

Positioning datum: the main feature of positioning workpiece, including positioning surface and positioning hole.

Fixture coordinate system: generally refer to the body coordinate system, the rear direction is positive x direction, and use the right-hand rule to judge the Z direction and Y direction,

Key points of fixture design size:

Safety first, in line with ergonomics.

The positioning point is consistent with the drawing, and has no interference with the parts, and the parts should be placed to avoid being stuck.

The measurement accuracy is up to the enterprise standard.

Avoid welding gun and spot, and guide welding.

The positioning pin is 3-5mm beyond the surface of the workpiece, preferably a fixed pin or a telescopic pin.

The pressing force of the pressing block is greater than 50kg to meet the welding requirements.

In order to prevent the pressure head from being too tight, a stop block is set at the pressure arm.

The support surface shall be 20x20mm as far as possible, and its adjustment direction shall be consistent with the body coordinate system.