JP2020133448A - Intake device of engine - Google Patents

Abstract

To improve combustion efficiency by efficiently suppressing the accumulation of deposits.SOLUTION: An intake device of an engine comprises: a cylinder head having an intake port performing air intake toward a combustion chamber; an intake valve movably supported with the cylinder head, and opening and closing the intake port; and an intake control cylinder arranged in an air intake passage including the intake port. An air flowing path is formed between a peripheral surface of the intake port and an outer circumferential surface of the intake control cylinder. As a result, a flow velocity of air flowing in the air flowing path which is formed between the peripheral face of the intake port and the outer circumferential surface of the intake control cylinder becomes higher than a flow velocity of air flowing in an internal space of the intake control cylinder, and air having high wind pressure flows along the peripheral face of the intake port, thus the air high in the wind pressure is blown to the peripheral face of the intake port and an external peripheral portion of an intake valve on which deposits are liable to be accumulated, consequently the accumulation of the deposits is efficiently suppressed and combustion efficiency can be improved.SELECTED DRAWING: Figure 1

Description

The present invention relates to the technical field of an engine intake device that suppresses the accumulation of deposits on an intake port and an intake valve.

The vehicle is provided with an internal combustion engine having an engine. In the engine, fuel is injected into the combustion chamber when intake air is taken from the intake port to the combustion chamber, and a mixture of air and fuel in the combustion chamber is injected. Is burned by the ignition of the spark plug, and power is generated in the piston. The burned air-fuel mixture is exhausted from the exhaust port.

In this way, in the engine, fuel is injected and the air-fuel mixture is burned, but a deposit is generated as an incomplete combustion product. The deposit is particularly likely to accumulate on the peripheral surface of the intake port and the outer peripheral portion of the intake valve, and is considered to be one of the causes of lowering the combustion efficiency of the engine.

Therefore, various techniques have been conventionally proposed in order to suppress the accumulation of deposits in each part (see, for example, Patent Document 1 and Patent Document 2).

Patent Document 1 describes a technique of suppressing the accumulation of deposits on the intake valve and the valve seat by discharging air from the air passage toward the outer peripheral portion of the intake valve and the valve seat when the intake valve moves.

In Patent Document 2, a rotatable intake control valve is arranged inside a manifold which is an intake passage, and a deposit is blown off by air flowing to the combustion chamber side through a through hole formed in the intake control valve. Techniques for suppressing deposition are described.

Japanese Unexamined Patent Publication No. 4-1404 JP-A-2007-239703

By the way, the deposit generated as an incomplete combustion product is deposited not only on the intake valve but also on the peripheral surface (wall surface) of the intake port. Therefore, in order to improve the combustion efficiency, not only the intake valve but also the intake air is taken. It is also necessary to suppress the accumulation of deposits on the peripheral surface of the port.

However, in the technique described in Patent Document 1 described above, although it is possible to suppress the accumulation of deposits on the intake valve and the valve seat, it is possible to suppress the accumulation of deposits on the peripheral surface of the intake port. That is not enough.

Further, in the technique described in Patent Document 2, the deposit is blown off by the air flowing to the combustion chamber side through the through hole of the intake control valve arranged inside the manifold. Since the structure is not such that the air is blown aiming at the portion where the deposit is likely to be accumulated, it may not be possible to obtain a sufficient effect in suppressing the accumulation of the deposit.

Therefore, an object of the present invention is to efficiently suppress the accumulation of deposits and improve the combustion efficiency.

The intake device of the engine according to the present invention is an intake device of an engine in a vehicle, and has a cylinder head having an intake port for sucking air toward a combustion chamber and an intake port movably supported by the cylinder head to open and close the intake port. An intake valve and an intake control cylinder arranged in an intake passage for air including the intake port are provided, and an air flow path is formed between the peripheral surface of the intake port and the outer peripheral surface of the intake control cylinder. It is a thing.

As a result, the flow velocity of the air flowing through the air flow path formed between the peripheral surface of the intake port and the outer peripheral surface of the intake control cylinder becomes faster than the flow velocity of the air flowing through the internal space of the intake control cylinder. High wind pressure air flows along the peripheral surface of the intake port.

Second, in the above-described engine intake device according to the present invention, the flow area of the air flow path is smaller than the flow area of the internal space in the intake control cylinder in a cross section orthogonal to the air flow direction. Is desirable.

As a result, the flow velocity of the air flowing through the air flow path becomes faster than the flow velocity of the air flowing through the internal space.

Thirdly, in the intake device of the engine according to the present invention described above, it is desirable that the intake control cylinder is formed with a flow hole for communicating the internal space of the intake control cylinder and the air flow path.

As a result, the air flowing in the internal space of the intake control cylinder is easily flowed from the flow hole toward the air flow path.

Fourth, in the intake device of the engine according to the present invention described above, the intake control cylinder includes a small diameter portion located on the combustion chamber side and a large diameter portion having a diameter larger than that of the small diameter portion. An intermediate portion located between the small diameter portion and the large diameter portion is provided, and a flow hole for communicating the internal space of the intake control cylinder and the air flow path may be formed in the intake control cylinder. desirable.

As a result, the pressure in the flow hole becomes negative due to the Venturi effect, and the air flowing in the internal space of the intake control cylinder is easily flowed from the flow hole toward the air flow path.

Fifth, in the above-described engine intake device according to the present invention, it is desirable that the flow holes are formed in the large diameter portion.

As a result, a negative pressure is generated in a region where the difference in flow velocity between the outer peripheral side and the inner peripheral side of the large diameter portion is large and the difference in flow velocity is large, so that the air flows from the internal space of the intake control cylinder toward the air flow path. The amount of air increases.

Sixth, in the above-described engine intake device according to the present invention, it is desirable that the flow hole is formed in the intermediate portion.

As a result, the flow hole is located at the portion that bends to the inner peripheral side with respect to the large diameter portion, so that the air flowing along the inner peripheral surface of the large diameter portion flows straight into the flow hole to control the intake air. The air that flows toward the combustion chamber in the internal space of the cylinder is easily flowed into the air flow path.

Seventh, in the above-described engine intake device according to the present invention, it is desirable that the flow holes are inclined in a direction approaching the combustion chamber from the inside to the outside.

As a result, air is more likely to flow from the internal space of the intake control cylinder toward the air flow path, so that the flow rate of the air flowing through the air flow path is larger and the flow rate is larger along the peripheral surface of the intake port. Air is flowed.

Eighth, in the above-described engine intake device according to the present invention, it is desirable that the intermediate portion is inclined with respect to the axial direction of the intake control cylinder.

As a result, the air is smoothly flowed from the large diameter portion side to the small diameter portion side without reducing the flow velocity of the air flowing in the air flow path.

Ninth, in the above-described engine intake device according to the present invention, it is desirable that a plurality of the flow holes are formed so as to be separated from each other in the circumferential direction of the intake control cylinder.

As a result, air is flowed into the air flow path from the plurality of flow holes located apart from each other in the circumferential direction, and the air is flowed along the entire peripheral surface of the intake port.

According to the present invention, the flow velocity of air flowing in the air flow path formed between the peripheral surface of the intake port and the outer peripheral surface of the intake control cylinder is larger than the flow velocity of air flowing in the internal space of the intake control cylinder. Higher wind pressure air flows along the peripheral surface of the intake port, so high wind pressure air is blown to the peripheral surface of the intake port and the outer periphery of the intake valve where deposits are likely to accumulate, causing deposits to accumulate. It can be efficiently suppressed to improve the combustion efficiency.

2 to 9 show an embodiment of the intake device of the engine of the present invention, and this figure is a cross-sectional view of the engine. It is a perspective view of the intake control cylinder. It is sectional drawing which shows the state which the intake control cylinder is arranged in the intake port. It is sectional drawing for demonstrating the action of the intake control cylinder at the time of intake. It is sectional drawing which shows the state which the intake port is piled up. It is sectional drawing for demonstrating the operation of the intake control cylinder which concerns on the 1st modification at the time of intake | intake. It is sectional drawing which shows the example of the intake control cylinder which concerns on the 1st modification in which the inclined flow hole was formed. It is sectional drawing for demonstrating the operation of the intake control cylinder which concerns on the 2nd modification at the time of intake | intake. It is sectional drawing which shows the example of the intake control cylinder which concerns on the 2nd modification which the flow hole was formed in the intermediate part.

Hereinafter, embodiments for implementing the intake device of the engine of the present invention will be described with reference to the accompanying drawings.

The engine 1 is a multi-cylinder engine, and is configured as, for example, a multi-cylinder engine having four cylinders. These cylinders have the same configuration, and the configuration of one cylinder will be described below.

The cylinder of the engine 1 has a cylinder block 2 and a cylinder head 3, and each required part is supported by the cylinder block 2 and the cylinder head 3 (see FIG. 1).

The piston 4 is movably supported in the cylinder block 2, and the space in the cylinder block 2 in which the piston 4 is supported is formed as a moving space 2a. The piston 4 is provided with a connecting fulcrum portion 4a. The cylinder block 2 is coupled to the cylinder head 3 in one direction of movement of the piston 4.

One end of the connecting rod 5 is rotatably connected to the connecting fulcrum 4a of the piston 4, and the other end of the connecting rod is rotatably connected to a crankshaft (not shown). Therefore, when the piston 4 is moved with respect to the cylinder block 2, the driving force of the piston 4 is transmitted to the crankshaft via the connecting rod 5, and the linear motion is converted into the rotary motion.

An intake port 6 and an exhaust port 7 are formed in the cylinder head 3. In the cylinder head 3, the valve seat 8 is fixed to the opening 6a of the intake port 6, and the valve seat 9 is fixed to the opening 7a of the exhaust port 7. The intake side manifold 10 is connected to the intake port 6 side of the cylinder head 3, and the space 10a inside the intake side manifold 10 is communicated with the intake port 6. The exhaust side manifold 11 is connected to the cylinder head 3 on the exhaust port 7 side, and the space 11a inside the exhaust side manifold 11 is communicated with the exhaust port 7.

By connecting the intake side manifold 10 to the cylinder head 3, the intake passage 12 is formed by the space 10a of the intake side manifold 10 and the intake port 6. Further, by connecting the exhaust side manifold 11 to the cylinder head 3, the exhaust passage 13 is formed by the space 11a of the exhaust side manifold 11 and the exhaust port 7.

The space formed by connecting the cylinder block 2 and the cylinder head 3 is a combustion chamber 14, and the combustion chamber 14 is a space in which the intake port 6 and the exhaust port 7 are communicated with each other. Further, the combustion chamber 14 is a space that is communicated with the moving space 2a of the cylinder block 2.

An injector 15 and a spark plug 16 are attached to the cylinder head 3. One end of the injector 15 is provided as a fuel injection unit 15a, and fuel stored in a fuel gallery (not shown) is injected from the fuel injection unit 15a into the combustion chamber 14.

The fuel injected from the fuel injection unit 15a into the combustion chamber 14 is mixed with the air supplied from the intake port 6 to the combustion chamber 14, and the fuel and the air are mixed to generate an air-fuel mixture. The generated air-fuel mixture is ignited by the spark plug 16 to burn, and the combustion of the air-fuel mixture creates an explosive pressure in the combustion chamber 14. When the explosive pressure is generated, the piston 4 reciprocates with respect to the cylinder block 2, and the driving force of the piston 4 is transmitted to the crankshaft via the connecting rod 5.

An intake valve 17 that opens and closes the opening 6a of the intake port 6 is movably supported on the cylinder head 3.

The intake valve 17 has a valve stem 18 supported by the cylinder head 3, a valve head 19 continuous with one end of the valve stem 18, and a valve end 20 continuous with the other end of the valve stem 18. The diameter of the valve head 19 is increased as the distance from the valve stem 18 is increased, and the diameter of the valve end 20 is larger than that of the valve stem 18.

A spring 21 is supported on the valve stem 18 on the valve end 20 side, and the intake valve 17 is urged by the spring 21 in a direction in which the valve head 19 closes the opening 6a of the intake port 6. Therefore, in a state where the intake valve 17 is not provided with a moving force toward the combustion chamber 14, the outer peripheral portion 19a of the valve head 19 of the intake valve 17 is pressed against the valve seat 8 by the urging force of the spring 21, and the opening is opened. 6a is blocked.

In the intake valve 17, the valve end 20 is pressed toward the valve head 19 by an intake drive cam (not shown). When the valve end 20 is pressed toward the valve head 19, the intake valve 17 is moved with respect to the cylinder head 3 against the urging force of the spring 21, and the opening 6a of the intake port 6 is opened. At this time, air is flowed to the intake port 6 through the intake side manifold 10, and the flowed air is flowed into the combustion chamber 14 from the intake port 6 to perform intake.

When the intake air to the combustion chamber 4 is performed, the pressing state of the intake drive cam on the valve end 20 is released, the intake valve 17 is moved with respect to the cylinder head 3 by the urging force of the spring 21, and the intake port 6 is opened. The part 6a is closed.

When the intake air is taken into the combustion chamber 14, fuel is injected from the fuel injection unit 15a into the combustion chamber 14 as described above, and the generated air-fuel mixture is ignited by the spark plug 16 to burn and burn the combustion chamber. Explosive pressure is generated at 14.

An exhaust valve 22 that opens and closes the opening 7a of the exhaust port 7 is movably supported on the cylinder head 3.

The exhaust valve 22 has a valve stem 23 supported by the cylinder head 3, a valve head 24 continuous with one end of the valve stem 23, and a valve end 25 continuous with the other end of the valve stem 23. The diameter of the valve head 24 is increased as the distance from the valve stem 23 is increased, and the diameter of the valve end 25 is larger than that of the valve stem 23.

A spring 26 is supported on the valve end 25 side of the valve stem 23, and the exhaust valve 22 is urged by the spring 26 in a direction in which the valve head 24 closes the opening 7a of the exhaust port 7. Therefore, when the exhaust valve 22 is not provided with the moving force toward the combustion chamber 14, the outer peripheral portion of the valve head 24 of the exhaust valve 22 is pressed against the valve seat 9 by the urging force of the spring 26, and the opening 7a Is blocked.

In the exhaust valve 22, the valve end 25 is pressed toward the valve head 24 by an exhaust drive cam (not shown). When the valve end 25 is pressed toward the valve head 24, the exhaust valve 22 is moved with respect to the cylinder head 3 against the urging force of the spring 26, and the opening 7a of the exhaust port 7 is opened. At this time, the burned air-fuel mixture flows into the exhaust port 7, and the inflowed air-fuel mixture flows toward the outside of the vehicle through the exhaust side manifold 11, and the burned air-fuel mixture is exhausted.

The engine 1 is controlled by an engine control unit (not shown). The engine control unit is an electronic control unit (ECU) that performs electronic control, and includes an input / output interface and peripheral circuits in addition to a microcomputer.

The engine control unit controls the fuel injection of the injector 15 in the engine 1, the ignition timing control of the spark plug 16, and the drive control of the intake valve 17 and the exhaust valve 18.

An air cleaner (not shown) is provided on the upstream side of the intake passage 12, and the air cleaned by the air cleaner flows from the intake passage 12 toward the combustion chamber 14. Further, a catalyst device (not shown) is provided on the downstream side of the exhaust passage 13, and the air-fuel mixture burned by the catalyst device is purified and discharged to the outside of the vehicle.

An intake control cylinder 27 formed of a metal material or a resin material is arranged in the intake passage 12. The intake control cylinder 27 is arranged in the intake passage 12, for example, the intake port 6. The intake control cylinder 27 is formed in a cylindrical shape curved along the shape of the intake port 6. In the following, in order to facilitate the explanation, the intake control cylinder 27 will be described in a non-curved shape.

The intake control cylinder 27 has a main body portion 28 formed in a tubular shape having a constant diameter, and mounting protrusions 29 and 29 protruding from the outer peripheral surface 28a of the main body portion 28 to the opposite side (see FIG. 2). ). The outer peripheral surface 28a of the main body 28 has a diameter smaller than that of the peripheral surface 6b of the intake port 6.

The cylinder head 3 is formed with a pair of groove portions 3a and 3a that open on the peripheral surface 6b of the intake port 6, and the pair of groove portions 3a and 3a are located 180 degrees opposite to the peripheral surface 6b (see FIG. 3). ..

The intake control cylinder 27 is arranged in the intake passage 12 by being inserted into the intake port 6 from the intake side manifold 10 side, and the mounting protrusions 29 and 29 are inserted into the groove portions 3a and 3a, respectively.

In the above, the intake control cylinder 27 is arranged in the intake passage 12 by forming a pair of groove portions 3a and 3a in the cylinder head 3 and inserting the mounting protrusions 29 and 29 into the groove portions 3a and 3a, respectively. Although an example is shown, for example, the intake control cylinder 27 may be arranged in the intake passage 12 by forming a pair of grooves in the intake side manifold 10 and inserting the mounting protrusions 29, 29 into these grooves. .. Further, a tubular partition wall is provided on the intake port 6 and the intake side manifold 10, a pair of grooves are formed on the inner peripheral surface side of the partition wall, and the mounting protrusions 29, 29 are inserted into these grooves to take intake air. The control cylinder 27 may be arranged in the intake passage 12.

Since the outer peripheral surface 28a of the intake control cylinder 27 has a smaller diameter than the peripheral surface 6b of the intake port 6, when the intake control cylinder 27 is arranged in the intake passage 12, it is between the outer peripheral surface 28a and the peripheral surface 6b. A space is formed in the air flow path 30 (see FIG. 4). The flow area of the air flow path 30 is smaller than the flow area of the internal space 27a in the intake control cylinder 27 in the cross section orthogonal to the air flow direction.

In the engine 1 configured as described above, the intake valve 17 which is movably supported by the cylinder head 3 having the intake port 6 and the cylinder head 3 to open and close the intake port 6 and the intake control cylinder 27 arranged in the intake port 6 Is a component of the intake device 50 (see FIG. 1).

In the engine 1, the fuel is injected and the air-fuel mixture is burned as described above, but a deposit P may be generated as an incomplete combustion product (see FIG. 5). The deposit P is particularly likely to be deposited on the peripheral surface 6b of the intake port 6 and the outer peripheral portion 19a of the valve head 19 in the intake valve 17, which is considered to be one of the causes of lowering the combustion efficiency of the engine.

In the engine 1, when intake air is taken from the intake passage 12 toward the combustion chamber 14, air goes to the combustion chamber 14 through the internal space 27a of the intake control cylinder 27 and the air flow path 30 (see FIG. 4). At this time, since the flow area of the air flow path 30 is smaller than the flow area of the internal space 27a, the flow velocity of the air A flowing through the air flow path 30 becomes faster than the flow velocity of the air B flowing through the internal space 27a. ..

Therefore, since the air having a high flow velocity flows along the peripheral surface 6b of the intake port 6, the deposit P is unlikely to be deposited on the peripheral surface 6b and the outer peripheral portion 19a of the valve head 19 in the intake valve 17. Even if the deposit P adheres to the peripheral surface 6b and the outer peripheral portion 19a of the valve head 19, the deposit P is blown to the combustion chamber 14 side by the air having a high flow velocity.

In this way, the flow velocity of the air flowing through the air flow path 30 formed between the peripheral surface 6b of the intake port 6 and the outer peripheral surface 27a of the intake control cylinder 27 is flowed through the internal space 27a of the intake control cylinder 27. Since the air velocity becomes faster than the flow velocity of the air and the air having a high wind pressure flows along the peripheral surface 6b of the intake port 6, a deposit P is accumulated on the peripheral surface 6b of the intake port 6 and the valve head 19 of the intake valve 17. It is difficult, and the accumulation of deposit P can be efficiently suppressed to improve the combustion efficiency.

Next, a modified example of the intake control cylinder will be described (see FIGS. 6 to 9).

The intake control cylinder 27A according to the first modification has flow holes 31, 31, ... Separated in the circumferential direction (see FIG. 6).

When the intake control cylinder 27A is used, the flow area of the air flow path 30 is smaller than the flow area of the internal space 27a, so that when intake is performed from the intake passage 12 toward the combustion chamber 14, The flow velocity of the air A flowing through the air flow path 30 becomes faster than the flow velocity of the air B flowing through the internal space 27a.

Further, since the flow hole 31 is formed in the intake control cylinder 27A, the pressure in the flow hole 31 becomes negative due to the Venturi effect, and the air flowing in the internal space 27a moves from the flow hole 31 to the air flow path 30. It becomes easier to flow toward. Therefore, since a large flow rate of air having a high flow velocity flows from the air flow path 30 along the peripheral surface 6b of the intake port 6, a deposit P is accumulated on the peripheral surface 6b and the valve head 19 in the intake valve 17. It is difficult, and even if the deposit P adheres to the peripheral surface 6b and the valve head 19, the deposit P is blown to the combustion chamber 14 side by a large flow rate of air having a high flow velocity.

As described above, since air having a large flow rate and high wind pressure flows along the peripheral surface 6b of the intake port 6, the deposit P is unlikely to be deposited on the peripheral surface 6b of the intake port 6 and the valve head 19 of the intake valve 17. , The accumulation of deposit P can be suppressed more efficiently, and the combustion efficiency can be further improved.

Further, since the intake control cylinder 27A is formed with a plurality of flow holes 31 separated in the circumferential direction, air is flowed from the plurality of flow holes 31 located separated in the circumferential direction to the air flow path 30. , Air flows along the entire peripheral surface 6b of the intake port 6, and deposit P is efficiently deposited on the peripheral surface 6b of the intake port 6 and the intake valve 17 on the entire circumference of the intake port 6 and the valve head 19. It can be suppressed.

The flow hole 31 may be inclined in a direction approaching the combustion chamber 14 from the inside to the outside with respect to the axial direction of the intake control cylinder 27A (see FIG. 7).

In this way, the flow holes 31 are formed in a shape that is inclined in the direction of approaching the combustion chamber 14 from the inside to the outside, so that air can easily flow from the internal space 27a toward the air flow path 30. , The flow rate of air flowing through the air flow path 30 becomes larger, and a larger flow rate of air flows along the peripheral surface 6b of the intake port 6, and the peripheral surface 6b of the intake port 6 and the valve head of the intake valve 17 Accumulation of deposit P on 19 can be suppressed more efficiently.

The intake control cylinder 27B according to the second modification has a small diameter portion 32 located on the combustion chamber 14 side, a large diameter portion 33 having a larger diameter than the small diameter portion 32, and a small diameter portion 32 and a large diameter portion 33. It has an intermediate portion 34 located between them, and the intermediate portion 34 is inclined with respect to the axial direction of the intake control cylinder 27B (see FIG. 8). The intake control cylinder 27B is formed with flow holes 31, 31, ... Separated in the circumferential direction in a portion of the large diameter portion 33 located on the intermediate portion 34 side.

When the intake control cylinder 27B is used, the flow area of the air flow path 30 is smaller than the flow area of the internal space 27a, so that when intake is performed from the intake passage 12 toward the combustion chamber 14, The flow velocity of the air A flowing through the air flow path 30 becomes faster than the flow velocity of the air B flowing through the internal space 27a.

Further, since the flow hole 31 is formed in the intake control cylinder 27B, the pressure in the flow hole 31 becomes negative due to the Venturi effect, and the air flowing in the internal space 27a moves from the flow hole 31 to the air flow path 30. It becomes easier to flow toward. At this time, the intake control cylinder 27B is provided with a small diameter portion 32 having a diameter smaller than that of the large diameter portion 33 on the manifold 14 side, and the flow area on the outer peripheral side of the small diameter portion 32 in the air flow path 30 is the large diameter portion. Since it is larger than the flow area on the outer peripheral side of 33, a large amount of air flowing through the internal space 27a is likely to flow from the flow hole 31 toward the air flow path 30.

Therefore, since a larger flow rate of air with a faster flow rate flows from the air flow path 30 along the peripheral surface 6b of the intake port 6, a deposit P is accumulated on the peripheral surface 6b and the valve head 19 of the intake valve 17. It is difficult, and even if the deposit P adheres to the peripheral surface 6b and the valve head 19, the deposit P is blown to the combustion chamber 14 side by the air having a high flow velocity.

In this way, since air with a higher flow rate and higher wind pressure flows along the peripheral surface 6b of the intake port 6, deposit P is unlikely to be deposited on the peripheral surface 6b of the intake port 6 and the intake valve 17, and the deposit P is difficult to accumulate. Accumulation can be suppressed more efficiently to further improve the combustion efficiency.

Further, since the intake control cylinder 27B has a flow hole 31 formed in the large diameter portion 33, the difference in flow velocity between the outer peripheral side and the inner peripheral side of the large diameter portion 33 is large, and negative pressure is generated in a region where the difference in flow velocity is large. Since it is generated, the amount of air flowing from the internal space 27a toward the air flow path 30 increases, and the accumulation of the deposit P on the peripheral surface 6b of the intake port 6 and the intake valve 17 is suppressed more efficiently. be able to.

Further, in the intake control cylinder 27B, the intermediate portion 34 is inclined with respect to the axial direction of the intake control cylinder 27B, and the air flows from the large diameter portion 33 side without reducing the flow velocity of the air flowing through the air flow path 30. Since the air is smoothly flowed to the small diameter portion 32 side, the accumulation of the deposit P on the peripheral surface 6b of the intake port 6 and the intake valve 17 can be suppressed more efficiently.

In the intake control cylinder 27B as well, similarly to the intake control cylinder 27A, the flow hole 31 may be inclined in a direction approaching the combustion chamber 14 from the inside to the outside with respect to the axial direction of the intake control cylinder 27B.

Further, although the example in which the flow hole 31 is formed in the large diameter portion 33 in the intake control cylinder 27B is shown above, the flow hole 31 may be formed in the intermediate portion 34 (see FIG. 9).

Since the flow hole 31 is formed in the intermediate portion 34 in this way, the flow hole 31 is located at the portion that bends to the inner peripheral side with respect to the large diameter portion 33, so that the flow hole 31 is located on the inner peripheral surface of the large diameter portion 33. The air flowing along the flow flows straight into the flow hole 31, and the air flowing through the internal space 27a toward the combustion chamber 14 is easily flowed into the air flow path 30, so that the peripheral surface 6b of the intake port 6 and the intake air are taken in. Accumulation of deposit P on the valve 17 can be suppressed more efficiently.

1 ... engine, 3 ... cylinder head, 6 ... intake port, 6b ... peripheral surface, 12 ... intake passage, 14 ... combustion chamber, 17 ... intake valve, 27 ... intake control cylinder, 27a ... internal space, 28a ... outer peripheral surface, 30 ... Air flow path, 27A ... Intake control cylinder, 31 ... Flow hole, 27B ... Intake control cylinder, 32 ... Small diameter part, 33 ... Large diameter part, 34 ... Intermediate part, 50 ... Intake device

Claims (9)

It is the intake device of the engine in the vehicle.
A cylinder head with an intake port that takes in air toward the combustion chamber,
An intake valve that is movably supported by the cylinder head and opens and closes the intake port,
It is provided with an intake control cylinder arranged in an intake passage of air including the intake port.
An intake device for an engine in which an air flow path is formed between the peripheral surface of the intake port and the outer peripheral surface of the intake control cylinder. The intake device for an engine according to claim 1, wherein the air flow path has a flow area smaller than the flow area of the internal space in the intake control cylinder in a cross section orthogonal to the flow direction of air. The intake device for an engine according to claim 1 or 2, wherein a flow hole for communicating the internal space of the intake control cylinder and the air flow path is formed in the intake control cylinder. The intake control cylinder includes a small diameter portion located on the combustion chamber side, a large diameter portion having a larger diameter than the small diameter portion, and an intermediate portion located between the small diameter portion and the large diameter portion. Is provided,
The intake device for an engine according to claim 1 or 2, wherein a flow hole for communicating the internal space of the intake control cylinder and the air flow path is formed in the intake control cylinder. The intake device for an engine according to claim 4, wherein the flow hole is formed in the large diameter portion. The intake device for an engine according to claim 4, wherein the flow hole is formed in the intermediate portion. The intake device for an engine according to claim 4, claim 5 or claim 6, wherein the flow holes are inclined toward the combustion chamber as the flow holes go from the inside to the outside. The intake device for an engine according to claim 4, claim 5, claim 6 or claim 7, wherein the intermediate portion is inclined with respect to the axial direction of the intake control cylinder. The intake device for an engine according to claim 3, claim 4, claim 5, claim 6, claim 7, or claim 8, wherein a plurality of flow holes are formed so as to be separated from each other in the circumferential direction of the intake control cylinder.

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