Working Principle of Drill

The internal combustion drill consists of a two-stroke single cylinder gasoline engine, air compressor and drilling equipment.In a cylinder, both the engine piston and the impact piston are installed at the same time, and the combustion chamber is formed between the two pistons in the small inner bore of the cylinder.

When the piston is in position to the left, the inlet and exhaust are closed and the combustible mixture entering the combustion begins to be compressed.At this point the impact piston due to the air resistance in the front lower compression chamber will not move forward.When the piston continues to move to the left to the position, the combustible mixture is compressed and the pressure is greatly increased. When the piston moves down to a certain position before the lower stop point, the magneto starts ignition of the spark plug, and the combustible mixture burns, producing high pressure and expansion work.At this point, the piston continues to move to the left to the bottom point, and the combustible mixture is exactly the highest pressure after full combustion, so the impact piston overcomes the air resistance of the compressed chamber and accelerates forward.At the same time, the pressure of the gas in the lower compression chamber is increased due to compression, and the exhaust valve is opened to allow part of the gas to be discharged, so as to reduce the movement resistance to the piston, so that it can obtain the maximum impact power, and violently impact the steel bar to carry out drilling work.

When the engine piston moves back to the right from the lower stop point, the combustion chamber's volume gradually increases and the pressure decreases. When the exhaust port and intake port are opened, the pressure is lower than the pressure in the compression chamber, so the impact piston begins to return to the original position at the top after making the impact work.

On the return trip of the engine piston, the exhaust port is first opened to drain the exhaust gas into the atmosphere.The intake opening is then opened, and the compressed combustible mixture in the crankcase is poured into the combustion chamber from the inlet, at which time the incoming fresh air is also used to accelerate the drive off the exhaust.This process is called ventilation and at the end of the process, a working cycle is completed.In this cycle, the crankshaft rotates once, the engine piston and the impact piston move back and forth for two strokes, and the impact piston hits the steel bar once.As the engine continued to run, the cycle began again.