10 problems and causes frequently encountered by drilling rigs

01 Why is it difficult for the drilling rig to start in winter?

It is difficult to start at low temperatures in winter, mainly due to the following reasons：

1. In winter, the climate is cold, the ambient temperature is low, the viscosity of the engine oil increases, and the frictional resistance of the moving parts increases, which reduces the starting speed and makes it difficult to start.

2. The battery capacity decreases as the temperature drops, which further reduces the starting speed.

3. Due to the decrease of the starting speed, the leakage of compressed air increases, and the heat dissipation of the cylinder wall increases, resulting in a great decrease in the temperature and pressure of the air at the end of the compression, so that the delay period of diesel ignition increases, and it can't even burn in severe cases.

4. The viscosity of diesel fuel at low temperatures increases, which reduces the injection speed. In addition, the swirl speed, temperature and pressure of the air at the end of compression are relatively low, so that the atomization quality of diesel fuel injected into the cylinder is poor, it is difficult to quickly form a good combustible gas with the air and ignite in time, or even fail to ignite, resulting in starting difficult.

02what are the conditions for good starting performance of the drilling rig?

1. There must be sufficient starting speed. The starting speed is high, the amount of gas leakage in the cylinder is small, the time for compressed air to transfer heat to the cylinder wall is short, and the heat loss is small, so that the gas temperature and pressure at the end of compression can be increased. Generally, the speed is required to be above 100r/min.

2. The sealing of the cylinder is better. This can further reduce the amount of air leakage, ensure that the gas has sufficient combustion temperature and pressure at the end of compression, and the compression pressure of the cylinder shall not be lower than 80% of the standard value.

3. It is required that the mating gap between the engine and the running parts is appropriate and well lubricated.

4. The battery must have sufficient starting capacitance, and the technical condition of the starting circuit is normal.

5. The amount of starting oil meets the requirements, the injection quality is good, and the injection advance angle must meet the requirements.

6. Use fuel that meets the requirements.

03the reason why the crankshaft cannot be rotated when the rc drilling rig starts

The reasons for the engine crankshaft not being able to rotate are described below.

1. The starter has poor meshing with the flywheel teeth. The ring gear and the starter gear will collide when starting the engine, causing damage to the teeth or wear on one side of the teeth. If more than three teeth are damaged or severely worn out in a row, it will be difficult for the starter gear and the ring gear teeth to engage.

2. Sticky cylinder. When the engine temperature is too high, it stops and turns off, and the heat is difficult to dissipate. The piston ring at high temperature sticks to the cylinder and cannot be started after cooling.

3. The crankshaft is locked to death. Dry friction of the plain bearing is caused by the failure of the lubrication system or lack of oil, which eventually locks the crankshaft and cannot be started.

4. The plunger of the fuel injection pump is stuck.

04the drilling rig can be rotated when it starts, but it cannot be started (there is no smoke in the exhaust pipe).

When starting the engine, the exhaust pipe is smokeless and there is no burst sound. It is generally an oil circuit problem. The detailed analysis is as follows：

1. There is no oil in the fuel tank.

2. The fuel filter and oil-water separator are clogged.

3. The low-pressure oil circuit does not supply oil.

4. The fuel injection pump does not pump oil.

5. There is air in the oil circuit.

6. The phase of the air distribution is misaligned. The opening time of the valve is not in harmony with the stroke of the piston in the cylinder. For example, when the piston is making a compression stroke in the cylinder, the inlet and exhaust valves are opened, and fresh air is driven out of the cylinder, so that there is no combustion gas in the cylinder and it cannot be started.

7. The solenoid valve of the type fuel injection pump is broken and is in a closed state, and the diesel cannot enter the high pressure chamber.

05the reason why the drilling rig is difficult to start or cannot start, and the exhaust pipe discharges a lot of white smoke

When the engine starts, the reasons for the large amount of white smoke discharged from the exhaust pipe are analyzed as follows：

1. There is water in diesel fuel, and the water evaporates into water vapor in the cylinder and is discharged from the exhaust pipe.

2. The cylinder head bolts are loose or the cylinder pads are washed out, causing cooling water to enter the cylinder.

3. There are trachoma or cracks somewhere in the cylinder block or cylinder head, and water enters the cylinder and evaporates and discharges.

06 the drilling rig is difficult to start or cannot be started, and there is a lot of gray smoke in the exhaust pipe

The engine is difficult to start, and the exhaust pipe discharges a large amount of gray-white smoke as diesel vapor.

1. The engine temperature is too low, and the diesel is not easy to evaporate and burn.

2. The injector has poor atomization.

3. The oil supply time is too late.

4. The oil supply is too small, and the mixture is too thin.

5. The cylinder leaks too much air, and the ignition temperature cannot be reached after compression.

07 the hydraulic drilling rig is difficult to start or cannot be started, and there is a lot of black smoke in the exhaust pipe

The engine is difficult to start, and the exhaust pipe discharges a lot of black smoke, which is the result of incomplete diesel combustion.：

1. Diesel is of poor quality.

2. The air intake is not smooth, and the air filter is clogged.

3. The fuel injection timing is adjusted prematurely.

4. The injector needle valve has poor sealing and oil dripping phenomenon.

5. The injection pressure is too low.

6. The fuel supply of the fuel injection pump is too large, and the combustion deteriorates.

7. The cylinder pressure is low and the atomization is poor.

08 the reason for the difficulty of hot starting the drilling rig

The cold start of the engine is good, but the ignition is turned off after the temperature rises for a period of time, and it is more difficult to start again, mainly due to the serious wear and tear of the plunger pair of the fuel injection pump and the needle valve pair of the fuel injector.

When the hot car starts, due to the higher temperature of the fuel injection pump and fuel filter, the viscosity of the fuel decreases, and the lower starting speed, most of the diesel oil leaks from the worn gap, resulting in insufficient starting oil and unable to start.

09 the low speed of the drilling rig is normal and there is a short-term high speed, and there is too little smoke exhaust.

The engine idles well, and the throttle speed can be increased rapidly, but the throttle speed is not easy to increase continuously. Driving is weak, or it is impossible to drive in gears above medium speed. This is caused by insufficient low-pressure oil supply.

1. The diesel filter or oil-water separator is clogged.

2. The low-pressure oil circuit is not smooth.

3. The oil supply to the oil pump is insufficient or the oil inlet filter is clogged.

4. The intake valve of the fuel tank cap failed. The above conditions can cause insufficient fuel pressure in the low-pressure oil chamber of the fuel injection pump, which can only maintain the oil supply required for a small load. When more oil supply is required for large and medium loads, it cannot be met, resulting in weak driving.

10 The low speed of the mounted drilling rig is normal but not high speed, and the smoke exhaust is too little.

The engine's low speed is good, but the speed cannot be increased when accelerating, and the driving is weak. This is caused by insufficient circulating oil supply.

1. Improper adjustment of the fuel injection pump reduces the oil supply.

2. The elasticity of the governor spring is reduced due to fatigue. When the throttle is stepped to the end, the oil volume adjustment lever cannot be moved forward to the head, resulting in a decrease in the fuel supply of the fuel injection pump and the engine cannot reach the rated speed.

3. The plunger and sleeve of the fuel injection pump, the needle valve of the injector and the needle valve body are severely worn out, which increases the leakage of diesel fuel when pumping oil, and the oil supply is relatively reduced.

4. Improper adjustment of the throttle control lever, or the accelerator pedal pin is too long, so that the accelerator pedal cannot be in place, resulting in too little oil supply at full load.

5. There is air in the oil circuit.