JP2008025344A - Intake system of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake system improving combustion efficiency and emission by inhibiting fuel attaching to the lower surface of a partition plate. <P>SOLUTION: The intake system 1A of an internal combustion engine has the partition plate 4 provided in an intake pipe 3 along a longitudinal direction to be divided into a first intake passage 5 and a second intake passage 6 at its inside, and is equipped with an intake control valve 10 for opening and closing the second intake passage. The second intake passage 6 and the intake control valve 10 are formed so that when the intake control valve 10 closes the second intake passage 6, intake air CGS passing through the first intake passage 5 and flowing back to the second intake passage 6 along the partition plate 4 is turned in a letter S manner and returned to the downstream. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an intake device for an internal combustion engine in which a partition plate is disposed in an intake pipe to control intake flow.

  Conventionally, a plurality of intake devices having a structure that generates a strong tumble flow in an intake pipe (also referred to as an intake port) have been proposed. For example, Patent Document 1 arranges a partition plate (also referred to as a partition wall, a partition wall, or the like) along the longitudinal direction inside an intake pipe, and divides it into an upper first passage and a lower second passage. In addition, a structure is disclosed in which two plate-like valve bodies that rotate about a support shaft are provided on the upstream side of the partition plate to open and close part of the intake pipe. If such a structure is adopted in the internal combustion engine, the opening ratio of the intake pipe can be adjusted, so that the tumble flow can be strengthened and stable combustion of the lean air-fuel mixture can be achieved.

JP 2004-124836 A

  In the intake device disclosed in Patent Document 1, fuel is injected to the tumble passage side, and the intake air flow after passing through the partition plate flows into the combustion chamber including the fuel. FIG. 3A schematically shows the state of the intake device 100 at this time. In the intake device 100, the inside of the intake pipe 103 is divided into a tumble passage 105 and a control passage 106 by a partition plate 104. FIG. 3A shows a state where the intake flow control valve 110 is rotated to close the control passage 106 side and a strong tumble flow is generated in the tumble passage 105. When such a state is formed, a part of the intake air flow after passing through the partition plate 104 may become a strong vortex EC at the lower end. This vortex EC flows backward through the control passage 106 and causes the fuel FU to adhere to the lower surface of the partition plate 104 in the form of droplets. Further, the fuel FU may adhere to the lower surface of the partition plate 104 due to blow-back when an intake valve (not shown) at the upper part of the cylinder is opened.

  The fuel FU that has flowed back or blown back is retained in the lower surface of the partition plate 104 or a recessed portion in the periphery. When the intake flow control valve 110 is switched to open (particularly fully open) while the injected fuel stays on the control passage 106 side in this way, as shown in FIG. The air / fuel ratio (A / F) suddenly becomes rich because it flows in at once. 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.

  Therefore, an object of the present invention is to provide an intake device that can suppress the fuel adhering to the lower surface of the partition plate and improve combustion efficiency and emission.

An object of the present invention is to provide an internal combustion engine having an intake control valve that opens and closes the second intake passage while providing a partition plate along the longitudinal direction in the intake pipe to divide the interior into a first intake passage and a second intake passage. In the engine intake device, when the intake control valve closes the second intake passage, the intake air that passes through the first intake passage and flows backward along the partition plate to the second intake passage is S-shaped. The second intake passage and the intake control valve are formed so as to be swung in a shape and returned downstream, and this can be achieved by an intake device for an internal combustion engine.
According to the present invention, since the second intake passage and the intake control valve are formed so that the intake air that flows backward is swirled in an S-shape and returned to the downstream side, the fuel stays in the second intake passage side. Can be suppressed. Therefore, it is possible to improve the combustion efficiency and the emission of the internal combustion engine.

The above object is also provided with an intake control valve that opens and closes the second intake passage while providing a partition plate along the longitudinal direction in the intake pipe to divide the interior into a first intake passage and a second intake passage. When the second intake passage is closed, the intake control valve receives the intake air that has passed through the first intake passage and has flowed back to the second intake passage along the partition plate. It can also be achieved by an intake device for an internal combustion engine, characterized in that it has a lower surface that is swung in an S shape and returned downstream.
Also according to the present invention, since the lower surface of the intake control valve is formed so that the intake air that flows backward is swirled in an S shape and returned downstream, it is possible to suppress the fuel from staying in the second intake passage side. Therefore, it is possible to improve the combustion efficiency and the emission of the internal combustion engine.

  Moreover, the said structure WHEREIN: The lower surface of the said intake control valve may be formed in the concave surface. In addition, the intake control valve may be formed so that the thickness decreases from the distal end portion to the proximal end portion.

  In addition, the upstream end of the partition plate may be bent so that the partition plate is connected to the intake control valve when the intake control valve closes the second intake passage.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel which adheres to the lower surface of a partition plate can be suppressed, and the intake device which can aim at the improvement of combustion efficiency and the improvement of emission can be provided.

  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 showing the intake device 1A.
1A of intake devices are arrange | positioned in the part which connects the 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 1A. The intake flow GS flows from the intake manifold side toward the cylinder as shown in the figure. 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 plate 4 is arranged along the longitudinal direction. The partition plate 4 divides the inside of the intake pipe 3 into a first intake passage 5 and a second intake passage 6. An injector mounting portion 7 is formed on the upper portion of the first intake 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. The Therefore, the intake air flow GS thereafter becomes an air-fuel mixture containing fuel.

  An intake control valve 10 is disposed upstream of the partition plate 4 (intake manifold side). The intake control valve 10 includes a support shaft 15 at an upstream end. The support shaft 15 is supported by a bearing provided on the inner wall of the intake pipe 3 and rotates around the bearing 16. In the illustrated example, a bearing 16 is disposed on the wall surface on the second intake passage 6 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.

  When the intake control valve 10 is in a position (reference (P)) that is tilted along the inner wall of the intake pipe 3, the intake pipe 3 is in an open state in which the opening ratio is maximized. On the contrary, when the intake control valve 10 is at a position where it rises in the intake pipe 3 (symbol (C)), the closed state where the opening ratio of the intake pipe 3 is minimized is obtained. The intake control valve 10 rotates between a position C that forms the closed state and a position P that forms the open state.

  There is a position where the valve tip 10a approaches the partition plate 4 while the intake control valve 10 is rotating from the open state to the closed state or from the closed state to the open state. Hereinafter, this position is referred to as a half-open position. Further, when the intake control valve 10 is in the half-open position, it is referred to as a half-open state. In FIG. 1, the intake control valve 10 in the half-open position is indicated with a symbol (M).

  The intake pipe 3 is formed with a recess 9 so as to extend outward. When the intake control valve 10 is in the fully open position P, the intake flow GS can flow smoothly downstream by storing it in the recess 9.

The intake control valve 10 is positioned so that the upstream end portion 4a of the partition plate 4 and the front end portion of the intake control valve 10 are connected when the intake control valve 10 reaches the half-open position (M). Thereby, the upper surface of the intake control valve 10 and the surface of the partition plate 4 on the first intake passage side 5 are connected, and the second intake passage 6 is closed.
As described above, the intake control valve 10 rotates in a cantilevered state because the support shaft 15 on the base end side is pivotally supported by the bearing 16 provided on the inner wall of the intake pipe 3.

  The intake control valve 10 is positioned at the fully closed position (C), the half open position (M), or the fully open position (P), thereby adjusting the strength of the dumble flow or the swirl flow generated in the combustion chamber. .

  FIG. 1 schematically shows the behavior of the fuel FU caused by the backflowed intake air flow CGS. Part of the intake air flow GS that has passed through the first intake passage 5 becomes a vortex EC near the downstream end of the partition plate 4. Due to this vortex EC, an intake air flow CGS that flows backward along the second intake passage 6 side of the partition plate 4 is generated. The intake air flow CGS that has flowed back to the upstream end of the partition plate 4 is swung in an S shape along the lower surface of the intake control valve 10 and is returned to the downstream side again along the inner wall surface of the intake pipe 3.

  As described above, the second intake passage 6 and the intake control valve 10 are formed so as to turn the backflowed intake flow CGS into an S shape and return it downstream. Specifically, the intake air flow CGS that has flowed back to the upstream end portion of the partition plate 4 is formed by the lower surface of the intake air control valve 10 so as to turn downstream. As a result, the swirled intake air flow CGS flows toward the downstream along the recess 9, so that it is possible to prevent the fuel from staying in the recess 9. That is, it is possible to suppress the fuel from staying in the second intake passage side 6. Since it is possible to prevent a situation in which the accumulated fuel suddenly flows, it is possible to improve the combustion efficiency and the emission of the internal combustion engine. Further, since the intake device 1A stabilizes the A / F, it is possible to obtain a stable output by suppressing the torque fluctuation of the internal combustion engine.

  Specifically, the lower surface of the intake control valve 10 is formed as a smooth concave surface, and the intake control valve 10 is formed so that the thickness of the central portion is thin and the thickness of the distal end portion and the proximal end portion is increased. Has been. As a result, the backflowed intake air flow CGS smoothly turns and returns downstream.

  Further, as described above, the front end portion 4a on the upstream side of the partition plate 4 is bent so that the front end portion of the intake control valve 10 is connected. Thereby, the surface of the partition plate 4 on the second intake passage 6 side and the lower surface of the intake control valve 10 are smoothly continued. Therefore, the intake air flow passing through the first intake passage 5 can be smoothly flowed downstream, and the intake CGS that has flowed back to the second intake passage 6 can be smoothly swung back to the downstream.

  Further, the intake control valve 10 receives a large pressure from the intake flow GS flowing from the upstream side toward the combustion chamber in a state where the second intake passage 6 is closed. For this reason, the intake control valve 10 receives pressure in the downstream direction. However, since the backflowed intake flow CGS swirls along the lower surface of the intake control valve 10, the intake control valve 10 is also subjected to pressure in the upstream direction. Thus, since the intake control valve 10 receives pressure from both the upper surface and the lower surface, the pressure received from the intake flow GS can be reduced.

  Next, a modified example of the intake device will be described. About the intake device 1B which concerns on a modification, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol to the part same as the intake device 1A mentioned above. FIG. 2 is a view showing the intake device 1B.

  The intake control valve 10B provided in the intake device 1B is formed so that the thickness decreases from the distal end portion to the proximal end portion. Further, the lower surface of the intake control valve 10B is formed in a planar shape. Even with such a configuration, the backflowed intake air flow CGS can be smoothly swung and returned downstream.

  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.

  The shape is not limited to the shape of the intake control valve described above. For example, the thickness may gradually decrease from the distal end portion to the proximal end portion, and the lower surface may be concave.

It is the figure shown about the intake device which concerns on Example 1. FIG. It is the figure shown about the intake device which concerns on a modification. It is the figure shown about the conventional intake device.

Explanation of symbols

1A, 1B Intake device 3 Intake pipe 4 Partition plate 5 First intake passage 6 Second intake passage 9 Recessed portion 10 Intake control valve FU Fuel GS Intake flow CGS Intake flow in reverse flow

Claims (5)

An intake device for an internal combustion engine having a partition plate along the longitudinal direction in the intake pipe to divide the interior into a first intake passage and a second intake passage, and an intake control valve for opening and closing the second intake passage In
When the intake control valve closes the second intake passage, the intake air that passes through the first intake passage and flows back to the second intake passage along the partition plate is swirled in an S shape to be downstream. An intake device for an internal combustion engine, wherein the second intake passage and the intake control valve are formed so as to return to An intake device for an internal combustion engine having a partition plate along the longitudinal direction in the intake pipe to divide the interior into a first intake passage and a second intake passage, and an intake control valve for opening and closing the second intake passage In
When the second intake passage is closed, the intake control valve causes the intake air that has passed through the first intake passage and flows back to the second intake passage along the partition plate to rotate in an S-shape. An intake device for an internal combustion engine, comprising a lower surface returning to the downstream.   The intake device for an internal combustion engine according to claim 1 or 2, wherein a lower surface of the intake control valve is formed as a concave surface.   3. The intake device for an internal combustion engine according to claim 1, wherein the intake control valve is formed to have a thickness that decreases from a distal end portion to a proximal end portion. 4. The partition plate is characterized in that the upstream end portion of the partition plate is bent so as to be connected to the intake control valve when the intake control valve closes the second intake passage. An intake device for an internal combustion engine according to any one of claims 1 to 4.

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