Inspection standard and description for appearance defects of precision stamping parts

1. Inspection method for rounded corners: visual inspection and inspection tool measurement rounded corner radius is not uniform enough, not clear and smooth enough. The outer cover is not allowed to exist. The rounded corners of some assembly surfaces and overlapping surfaces of the inner cover not only affect the appearance of the precision stamping parts, but also seriously affect the welding and assembly.

2 Pit bag inspection method: visual. The existence of pit bags seriously affects the appearance quality of the covered parts after painting, and is a defect that customers cannot tolerate. Large-area pits will also affect the strength and fatigue of precision stampings and cannot be repaired.

3 Material defect inspection method: Visual standard: material strength does not meet the requirements, traces left by rolled steel plates, overlapping, orange peel, streaks, loose galvanized surface, and peeling of galvanized layer.

4 Deformation (protrusions, depressions, waves) inspection methods: visual inspection, whetstone grinding, touch, and oiling Class A defects: defects that cannot be accepted by users, and users who have not been trained can also notice them. Freeze precision stamped parts immediately. Class B defect: It is an unpleasant defect, which is palpable, visible and determinable on the outer surface of precision stamping parts. Class C defect: It is a defect that needs to be corrected, and most of them are ambiguous. In some cases, it can only be seen after the whetstone has been polished.

5. Inspection method for bruises, indentations and scratches: The outer surface of the outer cover is not allowed to have bruises, scratches and indentations; the inner surface of the outer cover is not allowed to have scratches and indentations that affect the quality of the outer surface. The surface of the inner cover is not allowed to have serious scratches and indentations that may cause the parts to crack.

6. Wrinkle inspection method: Visually, the outer cover is not allowed to have any wrinkles that are easily noticed by the customer, and the inner cover is not allowed to have serious wrinkles to cause material stacking.

7 Burr inspection method: The length of the visual burr is required to be less than 10% of the thickness of the sheet. Any burrs that interfere with the fit of the weld lap are unacceptable. Any glitch that could easily cause personal injury is unacceptable. Any punching burrs that interfere with part positioning and assembly are unacceptable.

8. Stacking inspection method: Visually, the outer cover is not allowed to have stacking defects. Different degrees of stacking defects in the inner cover will cause customers to complain. Functional precision stamping parts also affect the assembly of the parts and the strength of the body.

9 Corrosion inspection methods: visual inspection, dissection. Rust is the rust caused by long-term storage or improper storage of precision stamping parts, which has a crucial impact on the function, strength and fatigue resistance of stamping parts.

10. Grinding defects, grinding marks Inspection methods: visual inspection, whetstone grinding Class A defects: polished through, clearly visible on the outer surface, and immediately visible to all customers. Class B defects: can be seen, touched, and proven after grinding in disputed areas. Class C defects: can be seen after grinding with whetstone.

11 Crack inspection method: Visual inspection. Any chipping of the outer cover is not acceptable. Only minor cracks of the inner cover are allowed to be repaired and repaired, but the repaired parts are not easy to be found by the customer and must meet the repair standards for precision stamping parts.

12 Neck inspection methods: visual inspection, dissection. Necking is a potentially dangerous rupture point in the forming process of precision stamping parts, which has a crucial impact on the function, strength and fatigue resistance of precision stamping parts. Determine whether the precision stamping parts are qualified, repaired, scrapped, etc. according to the degree of necking. The necking of the outer cover affects the appearance of the whole vehicle, which is not acceptable to customers.

13 Pock inspection methods: visual inspection, oil stone grinding, touch, and oiling Class A defects: Pocks are concentrated, and more than 2/3 of the entire area has pockmarks. Class B defects: pitting can be seen and touched. Class C defects: Separately distributed pits can be seen after grinding, and the distance between pits is required to be 300mm or more in zone 1.