Working Principle of Drill

Pneumatic drill is to use the distribution valve to change the direction of compressed air into the cylinder, so that the reciprocating movement of piston in the cylinder impact the gravel.

Working principle of butterfly - valve hammer drill

Working condition of stroke

When the butterfly valve closes the return air inlet on the seat and opens the stroke air inlet, the compressed air enters the upper chamber of the cylinder and pushes the piston downward.After the upper face of the piston crosses the vent, the upper chamber of the cylinder exhausts, while the air in the lower chamber is compressed. Therefore, the butterfly valve swings under the effect of the pressure difference between the left and right, closing the stroke intake port and opening the return intake port.The compressed air is diverted to the lower chamber of the cylinder.The piston continues to descend under the action of inertia until it hits the bottom.

Return trip status

The compressed air enters the lower chamber of the cylinder through the return air inlet and pushes the piston upward. When the lower end of the piston crosses the exhaust port, the lower chamber of the cylinder exhausts and the remaining air in the upper chamber is compressed.The pressure difference between the right lower and the left lower of the butterfly valve swung under the action of closing the return air intake port again and opening the stroke air intake port. The piston reached the top on the return journey under the action of inertial force.The piston moves back and forth in the cylinder to complete one working cycle at a time.The piston goes back and forth, and the drill works.

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.

Working principle of hydraulic drill: this machine is mainly composed of oil supply and oil distribution system, energy storage system, energy conversion system, vibration and support system, and working tool system.The impact cycle can be divided into four stages.

The first stage: the hydraulic oil from the high pressure oil source enters the lower end of the plunger and pushes the plunger upward.

Stage 2: in the rising process, the plunger is pushed upward to the fixed position, so the high-pressure oil passes through a calibrated inlet between the sleeve and the plunger to supply oil to the cavity, and the nitrogen energy storage device diaphragm also compresses nitrogen upward for energy storage.

Stage 3: when the liquid pressure on the upper end of the plunger exceeds the liquid pressure on the lower end, the imbalance of force causes the plunger to accelerate downward, and the energy reservoir provides the amount of oil required for rapid movement.In the process of downward movement, the plunger opens the throttling orifice so that the sleeve is also lowered.The plunger continues down until it hits the crushing tool.

Stage 4: during the downward movement of the valve sleeve, the oil supply to the cavity is cut off and connected to the low-pressure oil return circuit, so that the whole process is back to the initial position.This is repeated so that a continuous strike can be made automatically.