KR0149366B1 - Combustion chamber and tumble intake port of 4-valve engine - Google Patents

Abstract

By improving the shape of the combustion chamber and the intake port, it is possible to improve the fuel economy and engine output by improving the braking average effective pressure level in the low and medium speed range of DOHC engine, and also to reduce the harmful components of exhaust gas by rapid combustion. It is an object of the present invention to provide a combustion chamber and a tumble intake port of an internal combustion engine that can satisfy the strengthening regulations.

Accordingly, a DOCH type internal combustion engine comprising: an intake port formed in a cylinder head and into which a mixer is introduced; An intake valve disposed at a predetermined angle with the central axis of the intake port to selectively control the inflow of the mixer; An exhaust valve disposed at a predetermined angle with the central axis of the intake valve and spaced a predetermined distance from the lower end of the combustion chamber in a parallel or slightly inclined distance to maintain a slight inclination; A combustion chamber formed by the lower surface of the intake valve and the lower surface of the exhaust valve; In addition to being provided above the combustion chamber, it is characterized by a configuration including an ignition plug positioned in the center of the cylinder to combust the mixer introduced into the cylinder.

Description

Combustion chamber and tumble intake port of four-valve gasoline engine

1 is a view showing the intake and exhaust valve train of the internal combustion engine according to the present invention.

FIG. 2 is a bottom view of FIG. 1. FIG.

3 is a schematic view showing a shape of a combustion chamber according to the present invention.

4 is a flow state diagram of the mixer by the tumble intake port according to the present invention.

5 (a) and 5 (b) are graph diagrams for explaining premature combustion by delaying volume efficiency and spark timing by the tumble intake port according to the present invention.

6 is a view for explaining the MBT operation by the combustion chamber according to the present invention.

7 is a graph for explaining the persistence of the turbulence intensity by the tumble intake port according to the present invention.

8 is a graph for explaining that the lean limit of the air-fuel ratio by the tumble intake port according to the present invention is extended.

9 is a graph for explaining that the level of the BMEP is improved in accordance with the speed of the engine by the tumble intake port according to the present invention.

FIG. 10 is a graph for explaining the ignition advance and the ignition delay and main combustion time reduction by the tumble intake port according to the present invention. FIG.

11 is a graph for explaining fuel efficiency improvement by intake and exhaust valve angles according to the present invention.

FIG. 12 is a graph for explaining urban average effective pressure, NO _x , HC exhaust gas, and spike propagation and braking fuel consumption rate according to the exhaust gas recirculation rate by the tumble intake port according to the present invention. FIG.

13 is a view showing an intake and exhaust valve train of a conventional internal combustion engine.

FIG. 14 is a bottom view of FIG. 12. FIG.

15 is a graph for explaining the amount of residual gas according to the braking average effective pressure and rotational speed by the intake port and the combustion chamber according to the prior art.

Fig. 16 is a graph for explaining that the exhaust gas flows back at the end of the intake stroke by the intake port and combustion chamber according to the prior art.

17 is a graph for explaining that the air-fuel ratio is shifted to the lean side according to the throttle opening degree by the intake port and the combustion chamber according to the prior art.

* Explanation of symbols for main parts of the drawings

5: intake port 7: exhaust port

9: jaw 11, 13: intake valve

15, 17: exhaust valve 19: combustion chamber

19a, 21: inclined surface 19b: horizontal surface

96: spark plug A: inlet cross-sectional area

B: Cross section of middle section C: Cross section of outlet section

[Industrial use]

The present invention relates to a combustion chamber and a tumble intake port of a four-valve gasoline engine, and more particularly, to improve fuel economy and engine output by improving the level of braking average effective pressure in the low and medium speed range of a DOHC engine. The combustion chamber and the tumble intake port of the four-valve gasoline engine to reduce the harmful components of the warm water exhaust gas and improve the combustion stability.

[Prior art]

In general, DOHC engines install two intake and exhaust valves in each cylinder to improve the intake and exhaust efficiency according to the expansion of the intake and exhaust passages. Improving was the main design concept.

Therefore, the existing four-valve engine is selected by the timing of the intake valve of the high-speed, medium-sized type, and the exhaust gas flows back to the intake port at the end of the intake stroke at low speed and low load. As the surface area of the combustion chamber increases, the cooling loss increases at low and low loads, thereby increasing fuel consumption. In addition, in the combustion chamber and the intake port where the mutual inclination angles of the intake and exhaust valves are large and only the flow loss side of the mixer is emphasized, especially in the low speed region (less than 2500 rpm), the speed of the inflowing mixer is at the position of the intake port where the injector is installed. As it is lowered, the atomization state of the fuel is poor and the turbulence strength is weak at the partial load state where the low speed and the negative pressure in the intake port are generated.

Therefore, in order to solve this problem, a method of installing a control valve for inducing swirl in one of the two intake ports has been proposed, but the cost is increased and structurally complicated. Since the flow velocity in the circumferential direction becomes almost zero during flame propagation, it is difficult to generate flame nuclei at the theoretical air-fuel ratio, so that the main combustion time is shortened, but it causes knocking in order not to shorten the ignition delay. As a result, there have been suggested methods for optimizing the shape of the combustion chamber in the near term, but since the degree of freedom of geometric change is almost fixed, the room for improvement is almost limited, and exhaust gas is required due to excessive enrichment during warm and cold start-up. Causes excess emissions (HC) and poor fuel economy, nitrogen When the exhaust gas is recycled to reduce the oxide NO _x , the combustion state becomes unstable.

Accordingly, in the present invention, the tumble flow is generated in the cylinder by improving the shape of the combustion chamber and the intake port, thereby solving the problems caused by rapid combustion and stabilization of combustion.

FIG. 13 is a view showing the intake and exhaust valve train of the internal combustion engine of the prior art, and FIG. 14 is a bottom view of FIG. 13 by cams 50 and 52 of the intake cam shaft connected to an unshown crankshaft. The intake valves 54 and 56 that interlock are installed in the intake port 58 so that the mixer is selectively introduced, and the exhaust valves 64 that interlock by the cams 60 and 62 of the exhaust cam shaft. 66 is provided in the exhaust port 68 to exhaust the exhaust gas combusted in the combustion chamber 69.

The intake valves 54 and 56 and the exhaust valves 64 and 66 are inclined to the cylinder head CH at substantially the same angle toward the center of the cylinder 70. The intake and exhaust valves 54 The angle α between (56) and (64) (66) is typically 40 to 50 degrees.

In addition, the intake and exhaust valves 54, 56, 64, 66 are guided by respective valve guides 72, 74, 76, 78, and valve springs 80, 82. ), (84), (86) are installed, and the valve face 54a (56a), (64a) (66a) to the suction and exhaust ports (58) The sheets 80, 90, 92, 94 are provided in close contact with each other so as to maintain airtightness.

In addition, the front inner curvature R1 and the outer curvature R2 of the intake valves 54 and 56 installed at the intake port 58 may increase the R1 / R2 value to minimize the flow resistance of the inhaled mixer. It is intended to improve the high speed performance by minimizing the flow loss, and the angle? Between the central axis of the intake valves 54 and 56 and the central axis of the intake port 58 is typically designed to be 55 degrees or more.

On the other hand, the spark plug 96 which is provided for burning the mixer which flowed into the cylinder 70 is normally installed in the orthogonal direction toward the center of the cylinder 70.

In the prior art configured as described above, as the engine is operated, the intake and exhaust cam shafts connected to the crank shaft are interlocked so that the intake valves 54 and 56 are provided with the valve springs by the cams 50 and 52 provided on the intake cam shafts. The intake port 58 is opened and the piston (not shown) located at the top dead center is rotated by the crankshaft as it is guided to the valve guides 72 and 74 and is lowered by a predetermined distance. As a result of the lowering, the intake stroke in which the mixer is sucked is made.

In this state, the cams 50 and 52 provided to the intake cam shaft are interlocked by the rotational force of the crankshaft so that the intake valves 54 and 56 are restored to the initial state by the restoring force of the valve springs 80 and 82. Compression stroke that presses the valve seats 88 and 90 and the valve face 54a and 56a so that the airtight is preserved, and the piston rises from the bottom dead center to the top dead center to compress the inflowing mixer. This is done.

As described above, the compression stroke is performed and the mixer is combusted by the ignition of the spark plug 96, and the explosion stroke causes the crank shaft to rotate and transmit power by linearly moving the piston from the top dead center to the bottom dead center by the explosion pressure. And the exhaust valves 64 and 66 are connected to the valve springs by interlocking the cams 60 and 62 provided on the exhaust cam shaft when the piston reaches the top dead center from the bottom dead center by the rotational force of the crank shaft. 84 and 86, by overcoming the elastic force and lowering the predetermined distance, the exhaust port 68 is opened, and an exhaust stroke is performed in which the combusted exhaust gas is discharged to the outside.

[Problem to Solve Invention]

As described above, the conventional technology increases the number of intake and exhaust valves 54, 56, and 64, 66 when the function of one cycle is realized according to the operation of the engine, thereby increasing the filling efficiency of the mixer and the ability to discharge the exhaust gas. It is possible to increase the output performance of the engine at high speed, but the ratio of the cross-sectional area of the intake port 58 to the cylinder bore area during the intake stroke is large, so that the inflow rate of the mixer flowing through the intake port 58 is lowered, so that the low speed and low speed The fuel of the mixer under partial load hits the wall surface of the intake port 58, resulting in small particles, resulting in uniform mixing of the mixer and deterioration of fuel atomization, resulting in incomplete combustion and turbulence intensity, as well as in FIGS. 15 and 16. As shown in the figure, as the intake valve timing according to the intake flow rate decreases to the high speed side, a part of the exhaust gas combusted at the end of the intake stroke is reversed to increase the amount of residual gas. As the combustion state is deteriorated difficult to satisfy the exhaust gas regulating reinforced by being harmful components of the exhaust gas is increased, fuel consumption is to be reduced.

In addition, since the air-fuel ratio is shifted to the lean side during acceleration in a temporary state of the vehicle (cold start, worm-up, rapid acceleration and deceleration, etc.), fuel shortage is caused as shown in FIG. The level of Brake Mean Effective Pressure is lowered, the tolerance limit for Exhaust Gas Recirculation Rate is deteriorated, and the knocking phenomenon is increased, resulting in Minimum Advanced for Best Torque (MBT). There is a problem that can not be operated.

In addition, when an intake flow control valve for inducing swirl is installed in one of the two intake ports, the swirl flow of the inhaled mixer is ignited because the spark plug 96 is disposed toward the center of the cylinder 70. As the flow velocity in the circumferential direction becomes almost zero at the position of the plug 96, flame nucleation is insignificant and combustion is slow, and the angle formed by the central axis of the intake and exhaust valves 54, 56, 64, 66 is formed. As (a) is large, the ratio of the surface area with respect to the volume of the combustion chamber 69 is large, and there exists a general problem which the fuel economy further falls by increasing cooling loss in a low speed area | region.

The present invention has been made to solve the problems of the prior art as described above, and an object of the present invention is to improve the shape of the combustion chamber and the intake port to improve fuel economy by improving the level of braking average effective pressure in the low and medium speed region of the DOHC engine. And the combustion chamber and the tumble intake port of an internal combustion engine that can satisfy the regulation of exhaust gas enhancement by improving the power output of the engine and improving the potential to reduce harmful components of exhaust gas by rapid combustion. have.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a DOHC type internal combustion engine, comprising: an intake port formed in a cylinder head and into which a mixer is introduced; An intake valve disposed at a predetermined angle with the central axis of the intake port to selectively control the inflow of the mixer; An exhaust valve disposed at a predetermined angle with the central axis of the intake valve and spaced a predetermined distance from the combustion chamber so as to be parallel to a horizontal plane of the lower end of the combustion chamber; A combustion chamber formed by the lower surface of the intake valve and the lower surface of the exhaust valve; The combustion chamber and the tumble intake port of the internal combustion engine, which are provided above the combustion chamber and are positioned at the center of the cylinder and include a spark plug for combusting the mixer introduced into the cylinder, are provided.

The intake port is characterized in that the inlet cross-sectional area and the middle cross-sectional area and the outlet side cross-sectional area of the ratio is formed to minimize the flow loss of the mixer during the intake stroke and to maximize the in-cylinder tumble moment.

Each of the cross-sectional areas described above is characterized in that the intermediate cross-sectional area is reduced to 20-22% of the inlet cross-sectional area and 65 of the outlet-side cross-sectional area.

In addition, the intake port has a conical shape in which the inlet valve sheet on the outlet side is formed in a conical shape so that a main flow is generated under the exhaust valve of the combustion chamber, and the main inlet port is directly above the cross section of the inlet port. A jaw is formed.

The angle formed with the central axis of the intake valve and the intake port is set to 40 degrees or less so that the mixer flowing along the intake port has a longitudinal tumble inflow parallel to the cylinder axis.

The intake valve described above is characterized in that a conical inclined surface is formed on the lower side of the valve face in close contact with the valve seat so that the intake mixer does not hit the exhaust valve and the flow spreads widely in the combustion chamber.

The valve guide for guiding the lift of the intake valve is installed to be received on the wall of the intake port so as to minimize the flow resistance of the mixer flowing along the intake port.

The angle formed by the center side of the intake valve and the exhaust valve is characterized in that it is designed at an angle of 25 degrees to reduce fuel loss by reducing the surface area ratio to the volume of the combustion chamber to improve fuel efficiency.

The combustion chamber is an inclined surface formed by the bottom surface of the intake valve and an inclined surface formed by the intake valve and the bottom surface of the exhaust valve disposed at a predetermined angle so as to induce an effective tumble inflow of the mixer and to effectively burn unburned gas. Characterized in that it has a shape having.

The spark plug provided on the upper side of the combustion chamber is provided with a fresh mixer by the intake air flow to remove residual gas around the electrode, and to cool the high temperature exhaust valve so that initial flame nucleation is well formed. It is installed in the direction orthogonal to the line connecting each cam center to be interlocked, and characterized in that disposed inclined toward the exhaust port side.

[Action]

In the present invention, the mixer is introduced into the cylinder through the intake port in accordance with the operation of the engine, the tumble inflow is made according to the ratio of the cross-sectional area of each intake port and the shape of the jaw and the combustion chamber formed on the lower side. As the combustion stability is secured by rapid combustion by the strong turbulence maintained until the end of the compression stroke due to the reduction of the loss and the tumble flow, it is possible to reduce the harmful components of the exhaust gas and satisfy the regulation of the exhaust gas strengthening.

EXAMPLE

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention in more detail as follows.

FIG. 1 is a view showing the intake and exhaust valve train of a four-valve gasoline engine according to the present invention, and FIG. 2 is a bottom view of FIG. 1, and the same components as those in the prior art are denoted by the same reference numerals.

The cylinder head CH is coupled to the upper side of the cylinder block 3 in which a plurality of cylinders 70 through which the piston 1 is lifted and guided by fixing means (not shown) such as bolts, and the cylinder head CH ) Is formed with an intake port 5 into which the mixer is introduced and an exhaust port 7 through which the combusted exhaust gas is discharged to the outside.

The intake port 5 has a different inlet cross section (A), a middle cross section (B), and an outlet cross section (C) so as to minimize flow loss of the inflow mixer and to effectively perform tumble flow. In this embodiment, the middle cross-sectional area (B) is reduced to 20 to 22% of the inlet cross-sectional area (A) and reduced to about 65% of the outlet-side cross-sectional area (C). Therefore, the ratio may be formed differently.

In addition, the intake port 5 is formed in the conical shape of the outlet side so that the flow is increased to the exhaust side of the combustion chamber is introduced into the mixing chamber, and the jaw 9 is formed in the outlet side cross-sectional area (C) part intake port Intake flow is made to the upper side of (5).

The intake valves 11 and 13 arranged at the predetermined angle β 'with the central axis of the intake port 5 and interlocked by the cams 50 and 52 of the intake cam shaft are provided with the intake port 5. It is installed on the outlet side of the slit to selectively control the inflow of the mixer.

In the present embodiment, the angle β 'is set to 40 degrees or less so that the tumbler is introduced into the mixer.

In the exhaust port 7, the exhaust valves 15 and 17, which are interlocked by the cams 60 and 62 of the exhaust camshaft, have a predetermined angle α ′ with the intake valves 11 and 13. Installed and discharged exhaust gas combusted in the combustion chamber 19 and spaced apart from the horizontal surface of the lower end of the combustion chamber 19 by a predetermined distance so that the lower end surfaces of the exhaust valves 15 and 17 are parallel or slightly inclined (about Less than 5 degrees).

The intake and exhaust valves 11, 13, 15, 17 are guided by respective valve guides 72, 74, 76, 78, and valve springs 80, 82. Valves 11a, 13a, 15a, and 17a are provided at the suction and exhaust ports 5 and 7 so that the force is applied upwardly. The sheets 88, 90, 92, 94 are in intimate contact with each other to maintain airtightness.

The intake valves 11 and 13 are brought into close contact with the valve seats 88 and 89 so that the inhaled mixer does not collide with the exhaust valves 15 and 17 and the flow spreads widely in the combustion chamber 19. Separate inclined surfaces 21 are formed below the valve faces 11a and 13a.

In addition, the valve guides 72 and 74 which guide the lifting and lowering of the intake valves 11 and 13 may reduce the flow resistance of the mixer introduced along the intake port 5. It is installed to be stored inside.

In this embodiment, the angle α 'formed between the central axes of the intake valves 11 and 13 and the exhaust valves 15 and 17 reduces the cooling loss by reducing the ratio of the surface area to the volume of the combustion chamber 19. Although it is designed at an angle of 25 degrees to improve fuel economy, it is not limited thereto, and it may be designed at an angle that reduces cooling loss.

As shown in FIG. 3, the combustion chamber 19 is an inclined surface 19a formed by the central axis of the intake port 5 and the bottom surface of the intake valves 11 and 13 arranged at a predetermined angle β '. ) And a horizontal surface 19b or a slight inclination (less than about 5 degrees) formed by the lower surfaces of the exhaust valves 15 and 17 disposed at a predetermined angle α 'with the intake valves 11 and 13. Consists of a shape with an induction tumble inflow.

The spark plug 96 provided at the upper side of the combustion chamber 19 to compress the mixer introduced into the cylinder 70 and then combusts the fresh mixture introduced by the turbulent flow to remove residual gas around the electrode, Each cam 50, 52 which interlocks the intake and exhaust valves 11, 13, and 15 and 17 so as to cool the high temperature exhaust valves 15 and 17 so that initial flame nucleation is well formed. ), (60) and (62) are installed in a direction orthogonal to the line (L) connecting the center and are inclined toward the exhaust port (7) side.

According to the present invention configured as described above, the intake valves 11 and 13 are provided with valve springs by the cams 50 and 52 provided on the intake cam shaft by interlocking the intake and exhaust cam shafts connected to the crankshaft as the engine is operated. Overcoming the elastic force of (80) (82) and guided by the valve guides (72) (74), the predetermined distance is lowered as the intake port (5) is opened and at the same time the piston (1) located at the top dead center is in response to the rotation of the crankshaft. As a result of the lowering, the suction stroke into which the mixer flows into the cylinder 70 is made.

At this time, when the intake valves 11 and 13 are fully open, the inflow of the mixer is introduced by a constant ratio between the inlet cross section A formed in the intake port 5 and the middle cross section B and the outlet cross section C. The flow moment is maintained without loss, and the flow loss is further reduced by preserving the state in which the valve guides 72 and 74, which guide the intake valves 11 and 13, are stored on the wall surface of the intake port 5. The filling efficiency of the mixer filled in the 70 is increased, and a flow is generated in the upper side of the intake port 5 by the jaw 9 formed at the lower side of the intake port 5, and the intake valves 11 and 13 The inclined surface 21 provided separately at the lower ends of the valve faces 11a and 13a of the valve flows to the exhaust port 7 side of the combustion chamber 19, and as a result, the cylinder 70 as shown in FIG. A tumble inflow parallel to the axis of Δ is formed.

Therefore, as shown in FIG. 5 (a), while the volume efficiency is increased or maintained in the low and medium speed regions without loss, rapid combustion can be performed even when the ignition time is delayed in the entire throttle opening degree as shown in (b). You will see that you can get it.

In addition, the mixer packed in the combustion chamber 19 can maintain the uniform state of the fuel sufficiently atomized, and can improve the knocking limit and the rise of the level of the braking average effective pressure at low and medium speeds. MBT operation as shown in FIG. 7 is enabled, and sufficient turbulence strength is maintained until the compression stroke top dead center 30 degrees in the suction stroke, which is a characteristic of the tumble flow, as shown in FIG. In addition to shrinking, a stable combustion state can be obtained.

As shown in FIG. 8, as the lean limit of the air-fuel ratio is expanded, the rate of change of the Indicate Mean Effective Pressur decreases, and the brake specific fuel consumption decreases, thereby reducing the rich amount during cold start-up. It is possible to reduce, i.e., increase the lean air-fuel limit to improve emission and fuel economy.

In addition, the tumble is introduced into the mixer, and the exhaust valves 15 and 17 provided in the exhaust port 7 are spaced apart from the lower surface of the combustion chamber 19 by a predetermined distance in a parallel or slightly inclined horizontal plane 19b. And the combustion chamber 19 formed by the inclined surface 19a which is inclined with the lower end surfaces of the intake valves 11 and 13, the maximum throttle opening degree from the rotational region and the partial load region is shown in FIG. As shown in FIG. 10, it can be seen that the braking average effective pressure is increased, and as shown in FIG. 10, the ignition advance, initial ignition delay, and main combustion time are reduced.

In addition, the angle α 'formed by the central axes of the intake and exhaust valves 11, 13, and 15 and 17 is small, so that the ratio of the surface area to the volume of the combustion chamber 19 is reduced, resulting in cooling loss at low and low load conditions. As shown in FIG. 11, fuel efficiency is improved by improving fuel consumption as shown in FIG. 11, and as shown in FIG. 12, even if the exhaust gas recirculation rate is increased, the urban average effective pressure change rate is low, and NO _X and HC are reduced. In addition, the braking fuel consumption rate is reduced.

In this state, the cams 50 and 52 provided to the intake cam shaft are interlocked by the rotational force of the crankshaft so that the intake valves 11 and 13 are restored to the initial state by the restoring force of the valve springs 80 and 82. As a result, the valve seats 88 and 90 and the valve face 11a and 13a come into close contact with each other to maintain the airtightness, and the piston 1 rises from the bottom dead center to the top dead center to compress the introduced mixer. A compression stroke is made.

Compression is performed and the mixer is combusted by the ignition of the spark plug 96, and the crankshaft rotates by transmitting the power by linearly moving the piston 1 from the top dead center to the bottom dead center by the explosion pressure. The explosive stroke is made, and the exhaust valves 15 and 17 are operated by the interlocking of the cams 60 and 62 provided on the exhaust cam shaft when the piston reaches the top dead center from the bottom dead center by the rotational force of the crankshaft. By overcoming the elastic force of the springs 84 and 86 and lowering by a predetermined distance, the exhaust port 7 is opened so that an exhaust stroke in which the burned exhaust gas is discharged to the outside is completed, thereby completing one cycle.

At this time, since the spark plug 96 is formed to be inclined from the center of the cylinder 70 toward the exhaust port 7 side, the lower end combustion chamber 19 of the intake valves 11 and 13 when the piston 1 moves to the top dead center in the compression stroke. The volume is small and the turbulent flow moves from the intake port 5 side to the exhaust port 7 side, whereby a fresh mixer flows into the electrode of the spark plug 96 to remove residual gas around the electrode, and the high temperature exhaust valve 15 Cooling the (17) results in good initial flame nucleation and improved knocking resistance.

[effect]

As described above, the combustion chamber and the tumble intake port of the internal combustion engine of the present invention have a shape in which the inclined surface formed by the bottom surface of the intake valve and the bottom surface of the exhaust valve are parallel or slightly inclined with the bottom surface of the combustion chamber. In addition, the inlet, the middle and the outlet portion have different cross-sectional area ratios, and a jaw is formed on the lower side to improve the shape of the intake port so that the tumble can be introduced due to the strong tumble generation at the end of the compression stroke. In the low and medium speed zones of DOHC engines, the combustion efficiency improves fuel economy and engine output as well as reduces the harmful components of exhaust gases due to rapid combustion. Can satisfy.

In addition, since the spark plug is inclined from the center of the cylinder to the exhaust port side, when the piston moves to the top dead center in the compression stroke, the combustion chamber volume of the lower end portion of the intake valve is small, and the turbulent flow moves from the intake port side to the exhaust port side. In the fresh mixer flows in to remove the residual gas around the electrode, and by cooling the exhaust valve of the high temperature, the initial flame nucleation is good and the knock resistance is improved.

Claims (10)

A DOHC type internal combustion engine, comprising: an intake port formed in a cylinder head and into which a mixer is introduced; An intake valve disposed at a predetermined angle with the central axis of the intake port to selectively control the inflow of the mixer; An exhaust valve disposed at a predetermined angle with the central axis of the intake valve and spaced a predetermined distance from the combustion chamber so as to be parallel to a horizontal plane of the lower end of the combustion chamber; A combustion chamber formed by the lower surface of the intake valve and the lower surface of the exhaust valve; Combustion chamber and tumble intake port of the internal combustion engine provided on the combustion chamber and located in the center of the cylinder and including a spark plug for combusting the mixer introduced into the cylinder. The internal combustion engine according to claim 1, wherein the intake port has a constant ratio of inlet cross section and middle cross section and outlet cross section so as to minimize flow loss of the mixer during the intake stroke and to effectively perform tumble flow. Combustion chamber and tumble intake port. 3. The combustion chamber and tumble intake port of an internal combustion engine according to claim 2, wherein each cross-sectional area is formed such that the middle cross-sectional area is reduced by 20 to 22% of the inlet cross-sectional area and 65% of the outlet cross-sectional area. The internal combustion engine of claim 1, wherein the intake port has a cutter shape in the shape of a cone in order to allow the inflow of the mixer flow to the exhaust combustion chamber side, and a jaw is formed directly on the outlet side cross-sectional area of the lower side of the intake port. Combustion chamber and tumble intake port. The internal combustion engine according to claim 1, wherein the angle formed by the central axis of the intake valve and the intake port is set to 40 degrees or less so that the mixer flowing along the intake port has a longitudinal tumble inflow parallel to the cylinder axis. Combustion chamber and tumble intake port. The internal combustion engine according to claim 1, wherein the intake valve has a separate inclined surface formed below the valve face in intimate contact with the valve seat so that the intake mixer does not hit the exhaust valve and the flow spreads widely in the combustion chamber. Combustion chamber and tumble intake port. The combustion chamber and the tumble intake of an internal combustion engine according to claim 1, wherein the valve guide for guiding the intake valves is installed on the wall of the intake port so as to reduce the flow resistance of the mixer flowing along the intake port. port. The combustion chamber of an internal combustion engine according to claim 1, wherein the angle formed by the central axis of the intake valve and the exhaust valve is designed at an angle of 25 degrees to reduce fuel loss by reducing the surface area ratio to the volume of the combustion chamber, thereby improving fuel efficiency. And tumble intake port. The combustion chamber of claim 1, wherein the combustion chamber is inclined to form a tumble inlet of the mixer and effective combustion of unburned gas, and a lower surface of the exhaust valve disposed at a predetermined angle with the intake valve. Combustion chamber and tumble intake port of an internal combustion engine, characterized in that formed in a shape having a horizontal plane or an inclined surface of less than 5 degrees. The method of claim 1, wherein the spark plug is connected to the intake and exhaust valves to flow in the fresh mixer by the turbulent flow to remove the residual gas around the electrode, and to cool the high-temperature exhaust valve to generate a good initial flame nucleus Combustion chamber and tumble intake port of an internal combustion engine, characterized in that it is installed in a direction orthogonal to the line connecting each cam center and inclined toward the exhaust port side.