JP2007182832A - Intake device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake device capable of efficiently forming swirl flow in a combustion chamber. <P>SOLUTION: The intake device 1 for the internal combustion engine is constituted to provide a partition part 4 in an intake pipe 3 so as to be divided into a main passage 5 and an auxiliary passage 6, and to arrange an intake control valve 10 for regulating intake flow GS flowing on the main passage 5 side. The auxiliary passage 6 is formed to allow the intake flow GS to flow toward a clearance SP formed between an intake valve 20 and the intake pipe when the intake valve 20 moves to the opening side from the closed position. In this intake device, since the auxiliary passage is formed to allow the intake flow to flow toward the clearance formed between the intake valve and the intake pipe when the intake valve moves to the opening side from the closed position, strong tumble flow can be efficiently formed in the combustion chamber to enhance the combustion efficiency of the internal combustion engine. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an intake device that improves the combustion efficiency of an internal combustion engine by controlling an intake flow flowing in an intake pipe.

  Conventionally, a plurality of intake devices having a structure for generating a strong vortex (also referred to as a swirl flow) in an intake pipe (also referred to as an intake port) have been proposed. For example, Patent Literature 1 discloses an intake device in which an intake control valve is disposed in an intake pipe and an auxiliary intake passage having a small passage area is provided. This intake device generates a strong swirl flow (lateral vortex flow) by closing the intake pipe side and flowing the intake flow into the auxiliary intake passage when the internal combustion engine is in a low load operation. Therefore, an internal combustion engine that employs this intake device can improve the combustion efficiency in the combustion chamber during low-load operation, so that it is possible to improve fuel consumption and emissions.

JP 60-101224 A

  However, an intake valve (intake bubble) is provided at the downstream end of the intake pipe, and the amount of intake air flowing into the combustion chamber is limited by the lift amount of the intake bubble. Further, even if a strong flow is formed in the intake pipe, the effect of forming a vortex flow in the combustion chamber is attenuated if the flow collides with an intake valve or an intake pipe inner wall. Since the intake device of Patent Document 1 does not consider such points, a strong vortex may not be formed in the combustion chamber.

  Further, the intake device of Patent Document 1 employs a butterfly type intake control valve. The butterfly-type intake control valve forms a fully open state by making the valve body parallel to the intake flow. Therefore, there is a problem that the intake flow is likely to be disturbed because the valve body is present in the intake flow even in the fully opened state. On the other hand, an intake device that generates a vortex by arranging a cantilever intake control valve in an intake pipe has been conventionally known. Since the cantilever intake control valve can be retracted so as not to obstruct the intake flow when the fully open state is formed, it is excellent in that the disturbance of the intake flow indicated above hardly occurs.

  However, in an intake device that employs a cantilever intake control valve, the fuel blown back from the downstream side of the intake control valve may form droplets, resulting in a liquid pool. If the fuel droplets flow into the combustion chamber all at once, the air-fuel ratio (A / F) changes abruptly and the combustion efficiency of the internal combustion engine deteriorates. This point will be described with reference to the drawings.

  FIG. 5A is a diagram showing a conventional intake device 100 that generates a tumble flow (longitudinal vortex flow) using a cantilever intake control valve. The case where the intake control valve 110 is rotated to be in a half-open state in which one side in the intake pipe 101 is closed is shown. At this time, a strong intake flow GS can be generated on one side. However, when this state is formed, a vortex EC may occur on the downstream side of the intake control valve 110. The vortex EC flows backward in the intake pipe 101, and the fuel FU adheres to the bottom surface of the intake control valve 110 and forms droplets. Further, the fuel FU that has been formed into droplets stays in the recessed portion 105 in the peripheral portion and becomes a liquid pool. When the intake control valve 110 is switched to open (particularly fully open) in a state where the injected fuel stays in the intake pipe 101 in this way, droplet-like fuel FU is blown into the combustion chamber all at once as shown in FIG. The air-fuel ratio suddenly becomes rich because it flows in. Since this change is sudden, it is extremely difficult to control the air-fuel ratio. For this reason, the combustion efficiency of the internal combustion engine is lowered and the emission is deteriorated.

  An object of the present invention is to solve the conventional problems described above and to provide an intake device capable of efficiently forming a vortex flow in a combustion chamber, and even if a cantilever intake control valve is adopted. It is an object of the present invention to provide an intake device that can suppress the influence of droplets.

  An object of the present invention is to provide an intake valve for an internal combustion engine in which a partition portion is provided in an intake pipe and divided into a main passage and an auxiliary passage, and an intake control valve for adjusting an intake flow flowing through the main passage is disposed. The auxiliary passage is formed so that the intake flow flows toward the gap formed between the intake valve and the intake pipe when the valve moves from the closed position to the open side. This can be achieved by an intake device of an internal combustion engine.

  According to the present invention, when the intake valve moves from the closed position to the open side, the auxiliary passage is formed so that the intake flow flows through the gap formed between the intake valve and the intake pipe. Since a strong tumble flow can be efficiently formed in the combustion chamber, the combustion efficiency can be increased. Therefore, it is possible to improve fuel consumption and emissions of the internal combustion engine.

  The auxiliary passage may be formed with reference to the gap formed when the intake valve is in a low lift position. By setting the auxiliary passage in this way, a stronger tumble flow can be reliably formed in the combustion chamber when the intake valve is in the low lift or middle lift position.

  In addition, it is preferable that the partition portion further includes a bypass passage that communicates the main passage and the auxiliary passage. Thus, if the partition part is provided with the bypass passage, it can be returned to the downstream side even if the fuel blows back in the intake pipe.

  The intake control valve may be a cantilever type. If it is a cantilever type, it will not obstruct the intake flow when the main passage is fully opened, so the intake flow can flow smoothly.

  Further, it is desirable that the opening on the main passage side of the bypass passage is formed at a position where it can be closed by the intake control valve. Thus, even if the bypass is provided with the bypass passage, when the main passage side is fully opened, it is possible to prevent interference between the intake flow flowing through the main passage and the intake flow flowing through the auxiliary passage.

  ADVANTAGE OF THE INVENTION According to this invention, the intake device which can form a vortex | eddy_current efficiently in a combustion chamber can be provided. Further, it is possible to provide an intake device that can suppress the influence of droplets even if a cantilever intake control valve is employed.

  Hereinafter, an intake device for an internal combustion engine according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating an overall configuration of an intake device 1 according to an embodiment. The intake device 1 is disposed at a portion connecting a cylinder side of an internal combustion engine (not shown) and an intake manifold. In FIG. 1, the lower end 2 is the cylinder side of the intake device 1. As shown in the drawing, the intake flow GS flows from the intake manifold side toward the combustion chamber (inside the cylinder). In general, the intake pipe of the intake device is often formed in the cylinder head of the internal combustion engine, but the intake device according to the present invention is not limited to such a form. The intake pipe may be a part of the intake manifold or a form existing as an independent pipe. The embodiment described below will be described without particularly limiting the place where the intake pipe is provided.

  Inside the intake pipe 3, a partition 4 is provided in an island shape along the longitudinal direction. The inside of the intake pipe 3 is a main passage 5 having a large passage area by the partition portion 4. The main passage 5 is divided into auxiliary passages 6 having a smaller passage area. An injector mounting portion 7 is formed on the upper portion of the main passage 5 so as to protrude outward, and fuel FU is injected into the intake pipe 3 from the tip 8 a of the injector 8 inserted into the mounting portion 7. Therefore, the intake air flow GS thereafter becomes an air-fuel mixture containing fuel. An intake valve 20 is provided at the end 2 of the intake pipe 3, and regulates the flow rate of the air-fuel mixture flowing into the cylinder (not shown). That is, since the passage area changes according to the lift amount (movement amount) LF of the intake bubble 20, the flow rate of the air-fuel mixture introduced into the combustion chamber can be adjusted.

  The auxiliary passage 6 is configured such that when the intake valve 20 moves from the closed position to the open side, the intake flow GS flows toward the gap SP formed between the intake valve 20 and the end 2 of the intake pipe 3. Forming. For example, the auxiliary passage 6 is desirably formed with reference to a gap formed when the intake valve 20 is in the low lift position. If the auxiliary passage 6 is formed in this way, a strong tumble flow can be formed when the intake valve 20 is in the low lift or middle lift position, as will be described later. When the internal combustion engine is operated at a low load, the air-fuel mixture supplied into the combustion chamber is throttled by the intake valve. In general, the intake valve position in such a state corresponds to the low lift position here. In the structure illustrated in FIG. 1, the lower wall surface of the intake pipe 3 and the lower surface side of the partition portion 4 are curved, and the intake air flow GS is formed in the gap SP formed when the intake bubble 20 is in the low lift position. The shape of the auxiliary passage 6 is designed so as to flow.

  When the intake valve 20 moves from the closed position to the low lift position, an annular space is generated around the intake bubble 20. The gap SP in this embodiment is a part of this space. In addition, if the area of the gap SP and the passage area (cross-sectional area) of the auxiliary passage 6 are set to substantially coincide with each other, the intake flow GS can be flowed more efficiently.

  A bypass passage 9 that connects the main passage 5 and the auxiliary passage 6 is formed in the partition portion 4. The bypass passage 9 is formed to return the droplets generated when the intake air flow GS flows backward to the downstream side. The effect of providing this bypass passage 9 will be described later.

  A cantilevered intake control valve 10 is disposed on the upstream side (intake manifold side) of the upper surface of the partition 4. A support shaft 15 serving as a center point of rotation is formed at the end of the intake control valve 10. The support shaft 15 is formed at an end portion far from the intake valve 20. Therefore, the intake control valve 10 is disposed from the support shaft 15 toward the downstream side. The support shaft 15 is supported by a bearing 16 provided on the inner wall of the intake pipe 3, and the intake control valve 10 is rotatable. A bearing 16 is disposed on the inner surface of the main passage 5 side.

  Further, the rotational force from the actuator 17 is transmitted to the support shaft 15. The drive of the actuator 17 is controlled by an ECU (Electronic Control Unit) 18. The ECU 18 may also be used as an ECU that controls an internal combustion engine (not shown). In this case, it is possible to move the intake control valve 10 to a desired position by controlling the actuator 17 according to the state of the internal combustion engine. The intake control valve 10 rotates from a state where the main passage 5 is opened (fully opened state) to a state where it is closed (fully closed state). FIG. 1 shows a state where the intake control valve 10 partially closes the inside of the main passage 5 (half-open state).

  Further, the opening 9HL on the bypass passage 9 side formed on the upper surface side of the partition portion 4 is formed at a position where the intake control valve 10 can be closed by the intake control valve 10 when the main passage 5 is fully opened. It is preferable to leave.

  FIG. 2 is a view for explaining the effect of the auxiliary passage 6 provided in the intake pipe 3 in the intake device 1. FIG. 2 shows a state where the intake valve 20 is in a low lift. Moreover, the partition part 4, the intake control valve 10, and the peripheral configuration are shown in a simplified manner as compared with FIG. The intake device 1 of the present embodiment aims at the gap SP formed between the intake pipe 3 and the intake valve 20 when the intake bubble 20 is in the low lift position as described above. Is formed. Therefore, the intake air flow GS-2 that has passed through the auxiliary passage 6 flows toward the gap SP formed between the intake pipe 3 and the intake valve 20. On the other hand, the main passage 5 has a larger passage area than the auxiliary passage 6, and a larger amount of intake air flow GS-1 flows than the auxiliary passage 6. The intake flow GS-1 flows so as to collide with the intake valve 20 when there is no intake flow GS-2 on the auxiliary passage 6 side. This state corresponds to the case of the conventional intake device.

  However, in the intake device 1 of the present embodiment, the intake flow GS-2 is formed. Therefore, since the two intake flows GS-1 and GS-2 are combined, it is possible to introduce the combined intake flow GS into the combustion chamber so as to avoid the collision of the intake flows GS-1. Therefore, in this case, a strong tumble TU can be generated in the combustion chamber while ensuring a sufficient flow rate.

  FIG. 2 illustrates a case where the intake valve 20 is in the low lift position and the intake control valve 10 is fully open. By rotating the intake control valve 10 and reducing the opening of the main passage 5, the combined state of the intake flows GS-1 and GS-2 can be appropriately adjusted. When such adjustment is performed, the strength and direction of the tumble flow generated in the combustion chamber can be changed.

  FIG. 3 is a view showing a result of comparison between the intake device of the present embodiment provided with the auxiliary passage 6 and a conventional intake device having no auxiliary passage. As shown in FIG. 3, when the auxiliary passage 6 is provided, a tumble flow stronger than that of the conventional device can be formed in the combustion chamber particularly when the intake valve 20 is in the middle lift position from the low lift position. . Therefore, when the internal combustion engine is in a low load state such as an idle state or in an intermediate load state, a strong tumble flow is formed in the combustion chamber, and efficient combustion can be performed.

  FIG. 2 shows a state in which the intake control valve 10 is fully opened, but the intake flow GS-2 is caused only to the auxiliary passage 6 side by rotating the intake control valve 10 and closing the main passage 5. A flowing state may be formed. In this state, the strongest tumble flow can be generated in the combustion chamber by restricting the intake air flow most. When such a state is formed when the internal combustion engine is in a low load state, it is possible to improve fuel consumption and emissions.

  FIG. 4 is a diagram schematically illustrating a state where the vortex EC is generated on the downstream side when the intake control valve 10 of the intake device 1 is in a half-open state. Since the intake device 1 employs the cantilever intake control valve 10, the intake flow is hardly disturbed when the main passage 5 is fully opened. On the other hand, when the intake flow GS is throttled, such as when a half-open state is formed, the vortex EC is generated as described above, and the fuel FU is blown back and may adhere to the periphery.

  However, since the intake device 1 is provided with a structure for coping with this, it is possible to cope with the occurrence of spray back. That is, a bypass passage 9 is provided in the partition portion 4. Even when the vortex EC is generated on the main passage 5 side and the fuel FU is blown back, the intake passage GS flows on the auxiliary passage 6 side, so that the inside of the bypass passage 9 is in a negative pressure state. Therefore, as shown in the figure, the injected fuel FU can be sucked out toward the auxiliary passage 6 and returned to the downstream side. Therefore, the intake device 1 can eliminate the inconvenience when the cantilever intake control valve 10 is employed.

  The opening 9HL on the main passage 5 side of the bypass passage 9 is preferably formed at a position where it can be closed by the intake control valve 10. If the opening 9HL is arranged in this way, the opening 9HL is closed when the intake control valve 10 is rotated and retracted so as to follow the partition portion 4 in order to form a fully opened state of the main passage 5. Therefore, when the fully open state is formed, it is possible to prevent the intake air flow GS flowing through the main passage 5 and the intake air flow GS flowing through the auxiliary passage 6 from interfering with each other.

  The intake device 1 of the embodiment described above causes the intake air flow GS to flow toward the gap formed between the intake valve 20 and the intake pipe 3 when the intake valve 20 moves from the closed position to the open side. An auxiliary passage 6 is formed at the bottom. Therefore, it is possible to efficiently form a strong tumble flow in the combustion chamber and increase the combustion efficiency. In particular, as shown in FIG. 3, when the intake valve 20 is at the low and middle lift position, a strong tumble flow can be formed without reducing the flow rate, so that the output of the internal combustion engine can be improved.

  Furthermore, by providing the bypass passage 9 in the partition portion 4, the fuel blown back can flow downstream through the auxiliary passage 6. Therefore, even if the cantilever intake control valve 10 is employed, it is possible to suppress a decrease in combustion efficiency and a deterioration in emissions due to the blown back fuel.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

It is the figure which showed the whole structure of the intake device which concerns on an Example. It is the figure shown in order to demonstrate the effect by having provided the auxiliary passage in the intake pipe about the intake device of an example. It is the figure shown about the result of having compared the intake device of the present Example which provided the auxiliary passage with the conventional intake device which does not have an auxiliary passage. It is the figure which showed typically a mode when a vortex generate | occur | produced in the downstream, when the intake control valve of the intake device of an Example is made into a half open state. It is the figure shown about the conventional intake device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Intake device 3 Intake pipe 4 Partition part 5 Main passage 6 Auxiliary passage 9 Bypass passage 9HL Main passage side opening 10 Intake control valve 15 Support shaft 16 Bearing FU Fuel GS Intake flow

Claims (5)

In an intake device for an internal combustion engine in which a partition portion is provided in an intake pipe and divided into a main passage and an auxiliary passage, and an intake control valve for adjusting an intake flow flowing through the main passage side is disposed.
The auxiliary passage is formed so that the intake flow flows toward the gap formed between the intake valve and the intake pipe when the intake valve moves from the closed position to the open side. An internal combustion engine intake device. 2. The intake device for an internal combustion engine according to claim 1, wherein the auxiliary passage is formed with reference to the gap formed when the intake valve is in a low lift position. 3. The intake device for an internal combustion engine according to claim 1, wherein the partition portion is further provided with a bypass passage that communicates the main passage and the auxiliary passage. 4. The intake device for an internal combustion engine according to any one of claims 1 to 3, wherein the intake control valve is a cantilever type. The intake device for an internal combustion engine according to claim 4, wherein the opening on the main passage side of the bypass passage is formed at a position where the opening can be closed by the intake control valve.

Images