Causes Of Common Faults Of Construction Machinery In Winter Construction

(1) The thermostat fails. For a YZ10B road roller, the water chamber under the water tank felt very cold when inspecting it, indicating that the cooling water was not fully circulated. After dismantling and inspecting the thermostat, it was found that there were ice cubes in the thermostat, which prevented the main valve from opening, causing the cooling water to be unable to circulate widely.

(2) The air path is blocked. After a ZL50 loader was started, it was found that the air pressure indicated by the air pressure gauge was always zero; when the air reservoir bleed switch was turned on, no air was discharged; when the air pipe between the compressor and the gas control valve was disassembled, air was discharged, indicating that The air pump works fine. After dismantling and inspecting the air pipe between the gas control valve and the gas storage tank, it was found that a small ice block blocked the air pipe at the connection between the copper gas pipe and the rubber hose, preventing gas from entering the gas storage tank, so the air pressure gauge had no indication. In winter, the water vapor in the brake air circuit often freezes into ice after shutdown, causing the air pipe to be blocked. Therefore, the water in the air reservoir and oil-water separator must be drained after each shutdown.

(3) The filter is clogged. A W4-60 excavator stalled shortly after it was started. A manual pump was used to pump oil to remove the air in the fuel pipeline. It still stalled shortly after it was started again. Check the oil pipe from the fuel tank to the fuel pump and the oil pipe from the fuel pump to the diesel filter. There are no blockages. Disassemble the diesel filter and find that the filter element is blocked by ice. The main reason is that when the machine was shut down and stored in the autumn, no seasonal maintenance was carried out. The original diesel oil had a higher freezing point. In winter, the diesel oil in the filter froze and the filter element was almost sealed. Although it could barely start, it failed due to the freezing of the diesel oil in the filter. The filter element is clogged, the diesel supply is insufficient, and the engine stalls automatically. After clearing the ice in the filter element and replacing the diesel oil, the diesel engine returned to normal operation when it was started again.

(4) Hydraulic oil freezes. For a ZL50 loader, after starting, it was found that the torque converter oil pressure (outlet pressure) was 0, the transmission control oil pressure was 0.5Mpa (normal value is 1.08-1.47Mpa), and the machine could not start driving after it was put into gear. I opened the transmission filler cap and found that the hydraulic oil had frozen into ice slag (wax-like). I then used a blowtorch to bake the transmission, filter and main oil pipeline. When I started it again, each instrument showed that the pressure was normal and the machine could drive normally. .

(5) Diesel freezes. A Shanghai 120A bulldozer suddenly ignited and stalled while leveling the site. When pumping oil with a manual pump, only a small amount of oil flows out from the bleed screw of the fuel injection pump; check the diesel tank and find that there is sufficient oil, but there is ice residue (wax) in the diesel; check the pipeline from the diesel tank to the fuel transfer pump and find that There is also ice residue in the pipe, causing the oil to flow sluggishly. The reason is that the original diesel tank was filled with 0# diesel, which caused the machine to freeze during winter operation. After cleaning the oil circuit and switching to low pouring point diesel, the diesel engine returned to normal operation and no flameout occurred again.