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Why does the manufacturing accuracy of the inspection fixture need inspection records and fill in the equipment inspection records when using inspection fixtures?

2023-04-08

When using the measuring fixture, there are seventeen reasons for the need to test records and fill in the equipment test records.

1. First select the same positioning point as the design datum. The positioning hole used for the locating pin must have corresponding accuracy requirements, and it must be both a stamping datum and a test and gage datum to ensure the design datum and product of welding The unification of the design basis to reduce the design error and facilitate the analysis of the cause of the error.
2. For fixtures with logical relationship between upper and lower procedures, the positioning datum must be unified in the design of upper and lower procedures, and it is required to be unified with the positioning datum of mold and gage.
3, try to avoid areas with reinforced pits or complex surface changes to avoid instability of the welded product due to the instability of the stamping part itself.
4. In order to ensure safe use, when the clamp is in the clamped state, it should be able to self-lock; the clamp opening should be limited and the opening angle should not be too large, generally less than 135o, except for special circumstances.
5. When the clamping surface of the chuck has an inclination, a limit block must be installed at the chuck arm.
6. When the chuck is positioned and welded, under the condition of positioning pin and inclined pressing surface, the manufacturable positioning block must be installed at the chuck arm, and the positioning is accurate before welding, otherwise the accuracy of the chuck will not be guaranteed Positioning (when clamping on a plane, it is allowed to not add a manufacturable positioning block).
7. The compression force of manual chuck is generally ≥50Kg.f (referring to the center of the point of action).
8. The length of the manual operation handle should be suitable, and the position of the handle when the clamp is opened should be above the horizontal plane.
9. If there is a sequence of fixture operations, the sequence should be marked on the handle.
10. For all supporting positioning points, under the condition of effective compression, it must be ensured that the workpiece is fully and reliably positioned, and the workpiece is not deformed or moved.
11. The surface quality of the workpiece should not be damaged during clamping. When clamping thin-walled stampings, measures should be taken to limit the clamping force, increase the contact area of the chuck, and increase the copper and aluminum gaskets.
12. When the chuck has a positioning pin or there is no support point at the chuck pressing position, a limit block must be installed on the chuck arm.
13. In the welding area far away from the positioning and clamping point, auxiliary support clamping points should be added to reduce the unqualified products caused by welding deformation.
14. The support and clamping point near the welding point must be designed with sufficient welding channels for the welding tongs or welding torch. For arc welding equipment, a corresponding anti-splash device must be designed to protect the supporting clamping profile and prolong the service life of the welding fixture.
15. The force application point of the fixture should be at the support of the workpiece, and the positioning point should be arranged close to the support. It is necessary to prevent the force couple formed by the support reaction force and the clamping force, the support reaction force and the gravity, which will cause the workpiece to deform.
16. When the inclined plane is compressed, the gap adjustment piece must be installed in the two component directions; when the plane is compressed, the gap adjustment piece must be installed under the vertical surface.
17. The diameter of the positioning pin penetrates the upper surface of the workpiece by 3~5mm. For the two reference pins for positioning a workpiece, in principle, one uses a round pin and the other uses a diamond pin.
18. The positioning block on the outer surface of the positioning part is made of nylon or polyurethane material to prevent damage to the surface of the workpiece.