Auto parts inspection method

1, inspection method

The inspection method refers to the damage of the parts by the inspector through the senses, and judges whether the parts are available according to experience. For example, by eye observation (or by means of a magnifying glass), the parts are damaged, obviously deformed, severely worn and cracked, and the material is deteriorated. The crack and rivet looseness are inspected by hand hammering, or compared with new and old parts. Inspection, etc.

2, measurement method

The measurement method refers to measuring the existing size and shape tolerance value of the part by using a measuring tool or a measuring instrument, and comparing with the allowable use value specified by the technical standard to determine whether the part can continue to be used. The commonly used amount has a ruler, a vernier caliper, a centimeter card (micrometer), a dial gauge, a thickness gauge, a tooth caliper and a special template.

3. Detection method

The flaw detection method mainly tests the micro cracks on the surface of the part and the internal concealment. Commonly used flaw detection methods in production include magnetic flaw detection, oil immersion knock, fluorescent flaw detection, ultrasonic flaw detection and hydraulic pressure test. Magnetic flaw detection: Magnetic flaw detection is widely used because of its accurate and rapid inspection. The principle is that the parts to be inspected are placed in an electromagnetic field to magnetize the parts. If there are defects such as cracks and voids on the surface or inside of the part, when the magnetic flux passes through the part to be inspected, the defect will be distorted or interrupted at the defect where the magnetoresistance is large, thereby forming a magnetic pole. At this time, magnetic iron powder is sprinkled on the surface of the part, and the iron powder is magnetized and adsorbed near the crack, showing the size, shape and position of the crack.