KR101208053B1 - Internal combustion engine with double piston head - Google Patents

Abstract

PURPOSE: An internal combustion engine with a double piston head is provided to rapidly deliver power by reducing the time for one cycle consisting of four strokes and by having a narrow explosion time interval. CONSTITUTION: An internal combustion engine(100) with a double piston head comprises a cylinder block(110), first and second piston heads(120,130), an intake valve(140), an exhaust valve(150), and an ignition plug(160). The gas mixed with air and fuel is burned in the combustion chamber(112) of the cylinder block. Intake and exhaust ports(114,116) are formed at different heights on the side wall of the cylinder block. The first and second piston heads are connected to the upper and lower parts of the cylinder block to reciprocate in turn. The intake and exhaust valves are mounted on the intake and exhaust ports, and close or open the ports. The ignition plug is mounted on the exhaust port and ignites the compressed mixed gas.

Description

Internal combustion engine with double piston head {INTERNAL COMBUSTION ENGINE WITH DOUBLE PISTON HEAD}

The present invention relates to an internal combustion engine having a double piston head, and more particularly, to an internal combustion engine having a double piston head coupled to reciprocally move the piston head above and below the cylinder block to reciprocate in cross direction.

In general, an internal combustion engine is an engine that obtains energy by burning an oxidant such as fuel and air in a combustion chamber. An exothermic reaction between a fuel and an oxidant combusted in a combustion chamber generates a gas of high temperature and pressure, thereby raising and lowering the piston. The piston is reciprocated, and the up and down reciprocation of the piston is converted into a crank mechanism to convert the rotational motion to obtain rotational power.

These internal combustion engines are divided into two-stroke engines and four-stroke engines according to the number of administrations.

The two-stroke engine is a two-stroke engine of the piston, that is, an engine that finishes one cycle in one round trip. The explosion or strong reciprocating motion occurs every two strokes of the piston.

The four-stroke engine is an internal combustion engine that completes the entire operation of the suction, compression, explosion, and exhaust in two reciprocating, four stroke strokes of the piston. They are pushed back to compress the mixture, pushed back as the mixture expands and finally moved back in to release the gas.

That is, the suction is a stroke for sucking fuel and oxidant (for example air) into the cylinder, the compression is a stroke for compressing a mixture of fuel and oxidant in the cylinder by a piston, and the explosion is an electrical discharge of the mixture of fuel and oxidant. The stroke is a stroke that obtains the force to move the engine by the expansion of the gas generated by igniting by a rapid exothermic reaction, and the exhaust is a stroke that discharges the completed gas out of the engine.

In the conventional structure of the four-stroke engine, a piston connected to the crankshaft by a connecting rod is inserted into the cylinder block, and the upper side of the cylinder block includes an intake port, an intake valve, an exhaust port, and an exhaust valve. The spark plug is coupled to the intake port side.

However, the conventional four-stroke engine has a problem in that the power transmission and power efficiency for the second rotation is reduced by making two revolutions in one explosion stroke.

In addition, the four-stroke route of intake, compression, explosion, and exhaust proceeds one by one, resulting in a longer cycle time, and thus an increase in the time interval between explosions, which is not applicable to engines requiring large power in a short time. .

Publication No.2000-0031721 (published June 05, 2000)

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a double piston head capable of delivering power quickly by reducing the time of one cycle consisting of four strokes of suction, compression, explosion, and exhaust and shortening the time interval at which the explosion takes place is provided. The purpose is to provide an internal combustion engine.

Still another object of the present invention is to provide an internal combustion engine having a double piston head which can have a great effect on an engine or a vehicle equipped with an engine that requires a large force in a short time due to rapid power transmission.

Still another object of the present invention is to provide an internal combustion engine having a double piston head capable of minimizing power loss caused by two revolutions in one explosion.

In order to achieve the above object, an internal combustion engine having a double piston head according to the present invention has a combustion chamber in which a mixed gas in which air and fuel are mixed is formed therein, and an intake port and an exhaust port are formed at different heights of the side surfaces. Cylinder block is formed;

First and second piston heads coupled to upper and lower portions of the cylinder block so as to reciprocate the combustion chamber and reciprocating in cross direction; And

And an intake valve and an exhaust valve mounted to the intake port and the exhaust port, respectively, to open or close the intake port and the exhaust port.

According to the above-mentioned means for solving the problems, the power can be transmitted quickly by reducing the time of one cycle consisting of four strokes of intake, compression, explosion and exhaust, and shortening the time interval at which the explosion takes place, and also the large power in a short time due to the fast power transmission. This can be a great effect on engines that require power or on vehicles with engines, and can minimize energy losses by offsetting idle.

1 is a cross-sectional view of an internal combustion engine having a double piston head according to an embodiment of the present invention.
2A to 2D are explanatory views of the operation relationship of the internal combustion engine shown in FIG.
3 is a cross-sectional view of an internal combustion engine having a double piston head according to another embodiment of the present invention.
4A to 4E are diagrams illustrating the operation relationship of the internal combustion engine shown in FIG. 3.

Hereinafter, the configuration and operation of the present invention will be described with reference to the accompanying drawings.

It should be noted that the same elements among the drawings are denoted by the same reference numerals and symbols as much as possible even though they are shown in different drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

In addition, when a part is said to "include" a certain component, this means that it may further include other components, except to exclude other components unless otherwise stated.

1 is a cross-sectional view of an internal combustion engine having a double piston head according to an embodiment of the present invention, which is a cross-sectional view of an internal combustion engine having one unit cylinder unit.

As shown in FIG. 1, the unit cylinder unit 100 includes a cylinder block 110, first and second piston heads 120 and 130, an intake valve 140, an exhaust valve 150, a spark plug 160, and a connecting rod. 170, the crank 180 is configured to be included.

The cylinder block 110 has a cylindrical shape as a whole and forms a space in which fuel is combusted, that is, a combustion chamber 112, and a mixture gas of air and fuel is combusted to explode.

At the same time, the cylinder block 110 guides up and down reciprocation of the first and second piston heads 120 and 130, and the first and second piston heads 120 and 130 are coupled to the inside of the cylinder block 110 so as to reciprocate up and down. One end of the connecting rod 170 is connected to the piston heads 120 and 130. As the crank 180 is coupled to the other end of the connecting rod 170, the vertical reciprocating motion of the first and second piston heads 120 and 130 is performed. It is transmitted by the connecting rod 170 to generate the rotational power as the crankshaft 182 rotates.

The first and second piston heads 120 and 130 are coupled to the upper and lower reciprocating motions of the cylinder block 110 to perform the crossover piston movement.

The outer circumference of the first and second pistons 120 and 130 is provided with an annular shape of the oil ring groove and the ordinary oil rings 122 and 132 are fitted in the oil ring grooves so that the outer periphery of the oil rings 122 and 132 forms the combustion chamber 112. The inner circumferential surface of the block 110 is closely closed.

On the side of the cylinder block 110, an intake port 114 is formed on the upper side, and an exhaust port 116 is formed on the lower side, and each of the intake port 114 and the exhaust port 116 can be opened or closed. Intake valve 140 and exhaust valve 150 is mounted.

At this time, two or more intake ports 114 and two exhaust ports 116 are formed to shorten the intake stroke and the exhaust stroke time, and the intake valve 140 and the exhaust valve 150 are respectively mounted. do.

The intake port 114 is formed on the side of the cylinder block 110 at a position lower than the lower surface of the first piston head 120 when the first piston head 120 rises and is located at the top dead center, and the exhaust port 116. ) Is formed on the side of the cylinder block 110 at a position higher than the upper surface of the second piston head 130 when the second piston head 130 is lowered to the bottom dead center, and the intake port 114 and the exhaust port ( An upper limit line L1 of the second piston head 130 and a lower limit line L2 of the first piston head 120 are formed between 116.

In addition, the intake port 114 is equipped with an ignition plug 160 communicating with the combustion chamber 112 to generate a spark discharge during an explosion stroke of burning a mixed gas.

The spark plug 160 may be ignited without a spark plug when the fuel of the engine is diesel, and thus, the spark plug 160 may not be provided.

2A to 2D are explanatory views of the operation relationship of the internal combustion engine shown in FIG.

First, as shown in FIG. 2A, when the suction stroke is performed, the first piston head (1) is disposed in a state where the second piston head 130 is located at the bottom dead center and the exhaust valve 150 closes the exhaust port 116. 120 rises and the intake valve 140 opens the intake port 114 so that the mixed gas of air and fuel is rapidly sucked into the combustion chamber 112 through the intake ports 114 on both sides.

Next, when the compression stroke is performed as shown in FIG. 2B, the first piston head 120 is located at the top dead center, the intake valve 140 is the intake port 114, and the exhaust valve 150 is the exhaust port. In a state where all of the 116 are closed, the mixed gas inside the combustion chamber 112 is compressed by the rising of the second piston head 130 located at the bottom dead center.

Next, as shown in FIG. 2C, the explosion stroke is performed, and the mixed gas is ignited by the ignition plug 160, thereby rapidly burning and lowering the second piston head 130 by increasing the pressure of the combustion chamber 112. In this case, the force is transmitted to the crankshaft 182 through the connecting rod 170 so that the reciprocating motion of the second piston head 130 is converted into rotational motion.

Lastly, as shown in FIG. 2D, when the exhaust stroke is performed, the first piston head 120 is positioned at the bottom dead center of the second piston head 130 and the intake valve 140 is closed. ) Is lowered and the exhaust valve 150 opens the exhaust port 116 to quickly discharge the gas generated by the combustion of the mixed gas to the outside of the cylinder block 110 through the exhaust port 116 on both sides.

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3 is a cross-sectional view of an internal combustion engine having a double piston head according to another embodiment of the present invention, which is a cross-sectional view of a five-cylinder internal combustion engine having five unit cylinder units shown in FIG.

Hereinafter, the piston head reciprocating in the intake and exhaust stroke is called the first piston head (120,220), and the piston head reciprocating in the compression and expansion stroke is called the second piston head (130,220), understanding of the description In order to assist the odd-numbered unit cylinder unit is denoted by the reference numeral 100, even-numbered unit cylinder unit is denoted by the reference numeral 200.

As shown in FIG. 3, five unit cylinder units shown in FIG. 1 are arranged side by side, and the cylinder blocks 110 and 210 of the odd and even unit cylinder units 100 and 200 are shifted up and down from each other to have an odd number of cylinder blocks 110. The first piston head 120 in the upper portion, the second piston head 130 in the lower portion is coupled to the upper and lower reciprocating movement, the even number of cylinder block 210, the second piston head 230 in the upper portion, The first piston head 220 is coupled to the vertical reciprocating movement.

The odd cylinder block 110 has an intake port 114 at the upper side of the side, an exhaust port 116 is formed at the lower side, even cylinder block 210 has an exhaust port 216 at the upper side, An intake port 214 is formed at a lower portion thereof, and spark plugs 160 and 260 are mounted to the intake ports 114 and 214.

The spark plugs 160 and 260 may be ignited even without the spark plug when the fuel of the engine is diesel.

4A to 4E are diagrams illustrating the operation relationship of the internal combustion engine shown in FIG. 3.

First, when ignition occurs in the cylinder block 110 of the first cylinder unit 100a as shown in FIG. 4A, the first and second piston heads 120 and 130 are all located at the top dead center, and the intake valve 140 and the exhaust gas are exhausted. The mixed gas compressed by the spark plug 160 is ignited with the valve 150 closing both the intake port 114 and the exhaust port 116.

At the same time, a compression stroke is performed in the cylinder block 210 of the second cylinder unit 200a. The first piston head 220 is located at the bottom dead center, and the intake valve 240 and the exhaust valve 250 are intake ports 214. And the exhaust port 216 are all closed, the mixed gas in the combustion chamber 212 is compressed by the second piston head 230 is lowered.

In addition, the suction stroke is performed in the cylinder block 110 of the third cylinder unit 100b, with the second piston head 130 at the bottom dead center and the exhaust valve 150 closing the exhaust port 116. As the first piston head 120 rises and the intake valve 140 opens the intake port 114, the mixed gas of air and fuel is rapidly sucked into the combustion chamber 112 through the intake port 114 on both sides.

In addition, the exhaust stroke is performed in the cylinder block 210 of the fourth cylinder unit 200b, with the second piston head 230 at the top dead center and the intake valve 240 closing the intake port 214. The first piston head 220 rises and the exhaust valve 250 opens the exhaust port 216 so that the gas generated by the combustion of the mixed gas in the previous explosion stroke passes through the exhaust port 216 on both sides. It is quickly discharged to the outside of 210.

In addition, an explosion stroke is performed in the cylinder block 110 of the fifth cylinder unit 100c. The first piston head 120 is located at the top dead center, and the intake valve 140 and the exhaust valve 150 are intake ports 114. And the exhaust port 116 are all closed, while the mixed gas is burned, the pressure of the combustion chamber 112 is increased to apply a force falling to the second piston head 130 located at the top dead center.

The above-described compression stroke of the second cylinder unit 200a and the suction stroke of the third cylinder unit 100b by the descending force of the second piston head 130 according to the explosion stroke of the fifth cylinder unit 100c. The exhaust stroke of the fourth cylinder unit 200b is performed.

Next, as shown in FIG. 4B, an explosion stroke is performed in the cylinder block 110 of the first cylinder unit 100a. The first piston head 120 is located at the top dead center, and the intake valve 140 and the exhaust valve 150 are disposed. In the state in which both the intake port 114 and the exhaust port 116 are closed, while the mixed gas is combusted, the pressure of the combustion chamber 112 is increased to descend to the second piston head 130 located at the top dead center. I am forced to descend.

The compression stroke of the third cylinder unit 100b described later and the suction stroke of the fourth cylinder unit 200b by the descending force of the second piston head 130 according to the explosion stroke of the first cylinder unit 100a as described above. The exhaust stroke of the fifth cylinder unit 100c is performed.

At the same time, the ignition occurs in the cylinder block 210 of the second cylinder unit 100b. The first and second piston heads 220 and 230 are located at the bottom dead center, and the intake valve 240 and the exhaust valve 250 are intake ports. With both 214 and the exhaust port 216 closed, the mixed gas compressed by the spark plug 260 is ignited.

In addition, a compression stroke is performed in the cylinder block 110 of the third cylinder unit 100b, wherein the first piston head 120 is located at the top dead center, and the intake valve 140 and the exhaust valve 150 are intake ports 114. ) And the mixed gas inside the combustion chamber 112 is compressed by the second piston head 130 rising in a state where both the exhaust port 116 and the exhaust port 116 are closed.

In addition, the suction stroke is performed in the cylinder block 210 of the fourth cylinder unit 200b, with the second piston head 230 at the top dead center and the exhaust valve 250 closing the exhaust port 216. As the first piston head 220 descends and the intake valve 240 opens the intake port 214, the mixed gas of air and fuel is rapidly sucked into the combustion chamber 210 through the intake ports 214 on both sides.

And the exhaust stroke is performed in the cylinder block 110 of the fifth cylinder unit (100c), the second piston head 130 is located at the bottom dead center and the intake valve 140 closed the intake port 114 1 The piston head 120 is lowered and the exhaust valve 150 opens the exhaust port 116, so that the gas generated by the combustion of the mixed gas in the previous explosion stroke passes through the exhaust port 116 on both sides of the cylinder block ( It is quickly discharged outside of 110).

Next, as illustrated in FIG. 4C, an exhaust stroke is performed in the cylinder block 110 of the first cylinder unit 100a. The second piston head 130 is located at the bottom dead center, and the intake valve 140 is the intake port 114. ), The first piston head 120 is lowered and the exhaust valve 150 opens the exhaust port 116 in a closed state, so that the gas generated by the combustion of the mixed gas in the previous explosion stroke is discharged to both exhaust ports ( Through the 116 is quickly discharged to the outside of the cylinder block (110).

At the same time, an explosion stroke is performed in the cylinder block 210 of the second cylinder unit 200a. The first piston head 220 is located at the bottom dead center, and the intake valve 240 and the exhaust valve 250 are intake ports 214. ) And the exhaust port 216 are closed, while the mixed gas is burned, the pressure in the combustion chamber 212 is increased to apply a force to the second piston head 230 located at the bottom dead center to rise. .

The above-described exhaust stroke of the first cylinder unit 100a and compression of the fourth cylinder unit 200b described later by the rising force of the second piston head 230 according to the explosion stroke of the second cylinder unit 200a. The stroke and the suction stroke of the fifth cylinder unit 100c are made.

In addition, the ignition occurs in the cylinder block 110 of the third cylinder unit 100b, and the first and second piston heads 120 and 130 are located at the top dead center, and the intake valve 140 and the exhaust valve 150 are intake ports. The mixed gas compressed by the spark plug 160 is ignited with both the 114 and the exhaust port 116 closed.

In addition, a compression stroke is performed in the cylinder block 210 of the fourth cylinder unit 200b, and the first piston head 220 is located at the bottom dead center, and the intake valve 240 and the exhaust valve 250 are intake ports ( As the second piston head 230 descends while both the 214 and the exhaust port 216 are closed, the mixed gas inside the combustion chamber 212 is compressed.

In addition, the suction stroke is performed in the cylinder block 110 of the fifth cylinder unit 100c, and the second piston head 130 is located at the bottom dead center and the exhaust valve 150 closes the exhaust port 116. The piston head 120 rises and the intake valve 140 opens the intake port 114 so that the mixed gas of air and fuel is rapidly sucked into the combustion chamber through the intake port 114 on both sides.

Next, as shown in FIG. 4D, the suction stroke is performed in the cylinder block 110 of the first cylinder unit 100a. The second piston head 130 is located at the bottom dead center, and the exhaust valve 150 is disposed at the exhaust port 116. ), The first piston head 120 is raised and the intake valve 140 opens the intake port 114, so that the mixed gas of air and fuel is quickly transferred to the combustion chamber through the intake ports 114 on both sides. Is inhaled.

At the same time, the exhaust stroke is performed in the cylinder block 210 of the second cylinder unit 200a. The second piston head 230 is located at the top dead center and the intake valve 240 closes the intake port 214. The first piston head 220 rises and the exhaust valve 250 opens the exhaust port 216 so that the gas generated by the combustion of the mixed gas in the previous explosion stroke passes through the exhaust port 216 on both sides. It is quickly discharged to the outside of 210.

In addition, an explosion stroke is performed in the cylinder block 110 of the third cylinder unit 100b, and the first piston head 120 is located at the top dead center, and the intake valve 140 and the exhaust valve 150 are intake ports 114. ) And the exhaust port 116 are closed, while the mixed gas is burned, the pressure of the combustion chamber is increased to apply a force falling to the second piston head 130 located at the top dead center.

The suction stroke of the first cylinder unit 100a and the exhaust stroke of the second cylinder unit 200a by the descending force of the second piston head 130 according to the explosion stroke of the third cylinder unit 100b as described above. The compression stroke of the fifth cylinder unit 100c described later is performed.

In addition, the ignition occurs in the cylinder block 210 of the fourth cylinder unit 200b. The first and second piston heads 220 and 230 are located at the bottom dead center, and the intake valve 240 and the exhaust valve 250 are intake ports. With both 214 and the exhaust port 216 closed, the mixed gas compressed by the spark plug 260 is ignited.

And the compression stroke is made in the cylinder block 110 of the fifth cylinder unit (100c), the first piston head 120 is located at the top dead center, the intake valve 140 and the exhaust valve 150 is the intake port 114 The mixed gas inside the combustion chamber 112 is compressed by the second piston head 130 being raised in the state where both the exhaust port 116 and the exhaust port 116 are closed.

Finally, as shown in Figure 4e, the compression stroke is made in the cylinder block 110 of the first cylinder unit (100a), the first piston head 120 is located at the top dead center, the intake valve 140 and the exhaust valve The mixed gas in the combustion chamber 112 is compressed by the second piston head 130 being raised in a state in which 150 closes both the intake port 114 and the exhaust port 116.

At the same time, the suction stroke is performed in the cylinder block 210 of the second cylinder unit 200a, with the second piston head 230 at the top dead center and the exhaust valve 250 closing the exhaust port 216. As the first piston head 220 descends and the intake valve 240 opens the intake port 214, the mixed gas of air and fuel is rapidly sucked into the combustion chamber 212 through the intake port 214 on both sides.

In addition, the exhaust stroke is performed in the cylinder block 110 of the third cylinder unit 100b, with the second piston head 130 at the bottom dead center and the intake valve 140 closing the intake port 114. The first piston head 120 is lowered and the exhaust valve 150 opens the exhaust port 116, so that the gas generated by the combustion of the mixed gas in the previous explosion stroke passes through the exhaust port 116 on both sides. It is quickly discharged to the outside of the (110).

In addition, an explosion stroke is performed in the cylinder block 210 of the fourth cylinder unit 200b, and the first piston head 220 is located at the bottom dead center, and the intake valve 240 and the exhaust valve 250 are intake ports 214. ) And the exhaust port 216 are closed, and as the mixed gas is burned, the pressure in the combustion chamber 212 is increased to apply a force to the second piston head 230 located at the bottom dead center to rise.

The above-described compression stroke of the first cylinder unit 100a and the suction stroke of the second cylinder unit 200a by the rising force of the second piston head 230 according to the explosion stroke of the fourth cylinder unit 200b. The exhaust stroke of the third cylinder unit 100b is performed.

And the ignition occurs in the cylinder block 110 of the fifth cylinder unit (100c), the first and second piston heads (120, 130) are all located at the top dead center, the intake valve 140 and the exhaust valve 150 is the intake port ( The mixed gas compressed by the spark plug 160 is ignited in a state where both the 144 and the exhaust port 116 are closed.

As such, the force resulting from the explosion stroke of one cylinder unit of the plurality of cylinder units is used for the suction stroke, the compression stroke, and the exhaust stroke of the other cylinder unit, so that idling can be canceled and energy loss can be minimized through this.

Although the engine having the spark plugs 160 and 260, such as gasoline fuel, has been described above, for example, in the case of diesel fuel, since the ignition can be performed without the spark plug, the diesel engine does not have to have the spark plug.

100,200: cylinder unit 110,210: cylinder unit
114,214: intake port 116,216: exhaust port
120,220: first piston head 130,230: second piston head
140,240: intake valve 150,250: exhaust valve
160,260: spark plug 170,270: connecting rod
180: crank

Claims (8)

A cylinder block having a combustion chamber in which a mixed gas mixed with air and fuel is combusted, and an intake port and an exhaust port are formed at different heights of side surfaces;
A first piston head and a second piston head coupled to an upper portion and a lower portion of a cylinder block so as to reciprocate the combustion chamber and reciprocating in cross direction;
An intake valve and an exhaust valve mounted to the intake port and the exhaust port, respectively, to open or close the intake port and the exhaust port; And
A unit cylinder unit comprising an ignition plug mounted on the intake port communicating with the combustion chamber to ignite the compressed mixed gas,
The unit cylinder unit,
At the moment when the first piston head reaches the top dead center, the intake valve is opened to perform a suction stroke to suck the mixed gas into the combustion chamber.
While the first piston head is located at the top dead center, the second piston head is raised to perform a compression stroke to compress the mixed gas in the combustion chamber,
When the first piston head is located at the top dead center and the second piston head approaches the upper limit line, the ignition plug is operated to perform an ignition and explosion stroke to combust the mixed gas,
An internal combustion engine having a double piston head configured to exhaust the combustion gas in the combustion chamber while the exhaust valve is opened and the first piston head descends as soon as the second piston head descends to the bottom dead center. . The method of claim 1,
Any one of the intake port and the exhaust port is formed on the side of the cylinder block lower than the lower surface of the first piston head when the first piston head is located at the top dead center, the other port is the second port When the piston head is located at the bottom dead center is formed on the cylinder block side of the position higher than the upper surface of the second piston head,
The first piston head is lowered to the lower limit line between the intake port and the exhaust port, the second piston head is provided with a double piston head, characterized in that the rising limit line between the intake port and the exhaust port One internal combustion engine. delete The method of claim 1,
The internal combustion engine having a double piston head, characterized in that the intake port and the exhaust port is formed in two or more to shorten the time of the intake stroke and exhaust stroke. The method of claim 1,
The unit cylinder unit is made of five parallel, the cylinder block of the odd number unit cylinder unit and the cylinder block of the even number unit cylinder unit is an internal combustion engine having a double piston head, characterized in that the upper and lower sides. The method of claim 5,
Each of the unit cylinder units performs an intake stroke, a compression stroke, an ignition and an explosion stroke, an exhaust stroke, and five unit cylinder units are sequentially performed. The method according to claim 6,
An internal combustion engine having a double piston head, wherein the force generated in the explosion stroke of one of the five cylinder units is used for the suction stroke, the compression stroke, and the exhaust stroke of the other cylinder unit. delete

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