How to inspect stamping parts
Stamping parts are commonly used assembly parts, and its quality directly affects the appearance and function of the product. Controlling the quality of stamping parts can help us improve the overall quality of finished products.
In the stamping production process, due to various reasons, some defects such as pits, scratches, cracks, wrinkles, and drawing indentations may be caused on the surface of the stamping. Because the pits and bulging defects of stamping parts are common defects and are not easy to check out, relevant methods must be adopted for inspection. Here we introduce the inspection methods of various pits and drum kits.
A. Visual inspection
It is to directly find the location and type of the pit through the eyes of the inspector. This inspection method is easy and fast, and requires extensive inspection experience. The usual approach is to use sufficient light and take a certain angle to visually observe various parts of the stamping.
Because the sensitivity of the stamped parts is not good before painting, the visual inspection is more difficult. After the painting of the stamping parts is completed, it is easy to find such pits and bulges under the action of light refraction, so the visual inspection is more suitable for paint stamping Parts inspection, only obvious pits and bulges of stamping parts are suitable for this inspection method.
B. Feel check
Feel inspection is a main method of surface inspection of stamping parts. Due to the poor sensitivity of the surface of the stamped parts, it is not easy to check the defects such as pits and bulges before painting. These pits and bulges can be found using the tactile sensation of the palm. The feel inspection method is relatively difficult to master and requires long-term inspection experience and a lot of practice.
The specific method of feel inspection is: put your palms flat, put your fingers together, and place your hands on the area to be checked. The palm of your hand should be in contact with the surface of the stamping part, and slide back and forth on the fitting surface with appropriate force. There will be a strange feeling when you touch the bumps.
The advantages of the feel inspection are: a. It is suitable for all parts of stamping parts; b. It is not limited by working environment and light; c. It can detect some relatively small pits and bulging defects. The disadvantage of the feel check is that it is impossible to determine the location and size of the pits and packages. Usually, you need to use other auxiliary tools to determine the location and size before repairing.
C. Whetstone inspection
Whetstone can accurately check the position and size of the pits on the stamping parts, the defects of the bulge, and the changes of the defects during the repair process. There are many specifications of whetstone. The commonly used whetstone for inspection of stamping parts is a cuboid with a length of 20cm and a width of 1.5cm. When inspecting some arcs or narrow positions, a small whetstone can also be used. Its volume is only 1/3 of the size of the whetstone.
How to use Whetstone:
1. When using it, you must first remove the oil stains and some impurities on the surface of the oil stone and surface parts;
2. During the operation, the oilstone should pay close attention to the surface parts, the operation strength should be uniform and moderate, and the force should not be excessive.
3. During the inspection of the whetstone, stop working immediately when abnormal noise is found, use gauze to remove surface impurities or burrs before re-use;
4. When checking the arc surface, you must tilt the whetstone at a certain angle, the angle is related to the arc of the arc surface, the greater the arc, the greater the angle of inclination;
5. The trace width of each operation of the oil stone on the surface of the board should be more than half of the width of the oil stone. Adjust the angle of the oil stone and the running direction to increase the width of the operation area;
6. After inspecting the arc surface of the oil stone, you must re-check it with your hand. If the abnormality is found in the hand, it is a defect that cannot be detected by the oil stone (when the oil stone is not detected on a certain arc surface or when the surface defect is relatively large);
7. During the inspection of the oilstone, the running distance is related to the location of the inspection, and the stroke must be kept at a certain length, not too long or too short.
NBN Inspection as a Chinese inspection company, we provide quality inspection services for wide rang products in China.