Of course, replacing the girder can make the car meet the use requirements, but this repair method takes a long time, often taking several days to ten days. The repair cost of replacing the girder is high, ranging from several thousand yuan to tens of thousands of yuan. In particular, delays often cause great economic losses, which is even more unacceptable. Therefore, it is generally not considered to replace the girder.

2. Direct reduction after fracture or crack.

Repair the damaged part by butt welding without disassembly and repair. This repair method is to correct the bent part of the main beam, directly make an uphill slope on the inner and outer surfaces of the broken or cracked part, and repair the damaged part by butt welding, without disassembly and repair, and strengthen the partial repair of the broken part if necessary. In the process of repair, special attention should be paid to:

Is to do a good job of preparation before welding, thoroughly remove the paint, sludge and other dirt and impurities near the crack or fracture of the main beam, and make a certain angle groove on the inner and outer surfaces of the crack or fracture when the weld is not loaded (the original position before fracture); When welding, there should be no load at the weld to prevent residual stress and crack at the weld, which will lead to the weld fracture again; Is to keep the weld free to shrink when welding.

Extended data:

clean

The air contains a lot of dust, sediment and acidic substances, which are not only easy to be adhered by leaked fuel, but also easy to form a hard insulating layer under high temperature baking, which makes the heat dissipation performance of the parts worse, and is easy to be corroded by electrostatic adsorption of the car body and make it fade prematurely.

1, clean the air filter

Too dirty air filter will sharply prevent fresh air from entering the cylinder, resulting in excessive gas concentration, incomplete combustion, decreased power and excessive exhaust. Modern air filters generally use paper filter elements. Attention when cleaning: Do not use water or oil to clean, but use the method of beating and blowing. The beating method is to gently pat the end face of the filter element to make the dust fall off. Blow-clean method refers to blow-clean the inside of compressed air filter element, and the air pressure and force shall not exceed 0.3N/Pa.

2. Clean the oil filter

If the oil filter is blocked, it will hinder the flow of lubricating oil, resulting in poor engine lubrication, increased wear and even tile burning. Therefore, it should be cleaned or replaced regularly. If the climate is dry, it is usually replaced every 8000 kilometers. It should be shortened to 5 000km and replaced once.

Step 3 clean the battery

Modern cars generally use maintenance-free batteries. First, clean the top of the battery to avoid inter-electrode short circuit caused by electrolyte or other impurities. Secondly, clean the battery terminal to prevent the connector from generating oxide and causing poor contact. The vent hole should be clear to prevent the hand from bursting due to excessive pressure or high temperature in the battery.