JP2006207469A - Intake manifold for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To spread gas in intake air homogeneously while preventing a gas introduction pipe from increasing intake resistance of the intake manifold in the manifold having gas introduced therein. <P>SOLUTION: This intake manifold 1 is provided with a surge tank 2 including an intake air inlet 28, a manifold main body composed of a plurality of intake passages 3, 3, ... communicating with the surge tank 2, and the gas introduction pipe 44. The gas introduction pipe 44 is provided in the surge tank 2 to have an axis X thereof pass through a roughly center of the intake air inlet 28 in a view from a direction of intake air flowing into the surge tank 2 and extends to an inside of the surge tank 2, and an inside opening end 44a positioned in the surge tank 2 and introducing fuel evaporation gas into the surge tank 2 is positioned near an opening edge Y of the intake air inlet 28. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an intake manifold for an internal combustion engine.

  Conventionally, the intake system of an internal combustion engine is configured such that purge gas, EGR gas, blow-by gas, etc. in the fuel tank are introduced and mixed with the intake air, and these gases are sent together with the intake air to the combustion chamber of each cylinder. There is what I did.

For example, Patent Literature 1 discloses a purge pipe that is connected to a surge tank of an intake manifold. This purge pipe guides the fuel evaporative gas generated in the fuel tank to the surge tank through a valve or the like in order to prevent the fuel evaporative gas from spreading into the atmosphere in the fuel system of the internal combustion engine of the automobile. is there. In the intake manifold disclosed in Patent Document 1, a purge pipe whose one end on the fuel tank side is connected to a valve is brazed inside the surge tank, and the other end is in the vicinity of the intake inlet of the surge tank. In FIG. 1, the air intake is provided so as to protrude inward from the opening edge of the intake air inlet as viewed in the intake air inflow direction. By doing so, the purge gas introduced into the surge tank from the other end of the purge pipe is mixed with the intake air flowing into the surge tank from the intake inlet, and each combustion of the internal combustion engine is performed from the intake passage of the intake manifold together with the intake air. It is sent to the room.
JP-A-11-210573

  Incidentally, in the intake system of an internal combustion engine, it is necessary to reduce the intake resistance in order to improve intake charge efficiency. However, in the intake manifold disclosed in Patent Document 1, the other end of the purge pipe protrudes inward from the opening edge of the intake inlet when viewed in the intake air in the vicinity of the intake inlet of the surge tank. Therefore, the intake air flowing in from the intake inlet collides with the other end portion of the purge pipe, and the intake resistance increases.

  Further, the gas containing the fuel such as purge gas introduced into the surge tank needs to be uniformly diffused and mixed with the intake air in the surge tank from the viewpoint of making the air-fuel ratio of each cylinder of the internal combustion engine uniform. There is.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an intake manifold having a gas introduction pipe for introducing a gas such as fuel evaporative gas or EGR gas generated in the fuel tank. The introduction pipe diffuses the intake air uniformly while preventing the introduction pipe from increasing the intake resistance of the intake manifold.

  According to a first aspect of the present invention, there is provided a manifold main body comprising a surge tank having an intake inlet, a plurality of intake passages having one end communicating with an intake port of an internal combustion engine and the other end communicating with the surge tank; An intake manifold of an internal combustion engine including a gas introduction pipe for introducing at least one of fuel evaporative gas, EGR gas, and blow-by gas generated in the tank into the surge tank.

  The gas introduction pipe is provided in the surge tank and extends to the inside of the surge tank so that its axial line passes through the approximate center of the intake inlet when viewed in the intake air inflow direction to the surge tank. At the same time, it is assumed that the opening end that is located in the surge tank and introduces the gas into the surge tank is located in the vicinity of the opening edge of the intake inlet.

  According to a second aspect of the present invention, the manifold body is a resin molded product including a first divided body and a second divided body that are divided along the flow direction of the intake air, and the gas introduction pipe is divided into the first divided body. It is assumed that the body or the second divided body is integrally molded with a resin, and the axis thereof is provided so as to extend in the same direction as the die cutting direction at the time of molding of the integrally molded divided body.

  In the first aspect of the present invention, the gas introduction pipe provided extending in the surge tank is located near the opening edge of the intake inlet when the opening end located in the surge tank is seen in the intake inflow direction. The area of the gas introduction pipe that collides with the intake air can be kept small. In addition, the gas introduction pipe has a surge tank toward the center of the airflow of the intake air flowing from the intake air inlet by passing through the approximate center of the intake air inlet as seen in the intake air inflow direction. And the opening end of the gas introduction pipe is positioned in the vicinity of the opening edge of the intake air inlet as viewed in the intake air inflow direction, so that the gas enters the surge tank from the opening end. Since there is an intake airflow flowing in from the intake air inlet, the gas easily mixes with the intake air and diffuses into the surge tank along the intake airflow.

  Therefore, a gas introduction pipe extending into the surge tank is provided in the surge tank so that its axis line passes through the approximate center of the intake inlet when viewed in the intake inflow direction to the surge tank, and one end of the gas introduction pipe extends to the intake inlet. The gas introduced from the gas introduction pipe is prevented from increasing the intake resistance of the intake air flowing into the surge tank by being configured to be positioned near the opening edge of the intake air inlet as viewed from the direction. It is possible to uniformly diffuse the intake air in the surge tank.

  According to a second aspect of the present invention, there is provided a resin having a gas introduction pipe projecting into the surge tank by providing the gas introduction pipe so as to extend in the same direction as a die-cutting direction at the time of molding of the divided body integrally formed with the axis. The intake manifold of the molded product can be easily manufactured. Here, each divided body is usually easy to die when the die-cutting direction at the time of molding is a direction intersecting the dividing surface. Further, since the gas introduction pipe is provided so that the axis thereof passes through the approximate center of the intake air inlet when viewed in the intake air inflow direction, the gas introduction pipe extends in a direction intersecting the intake air flow direction in the surge tank. In other words, by dividing the manifold main body along the flow direction of the intake air, the axis of the gas introduction pipe extends in a direction intersecting with the division plane, so that the axis of the gas introduction pipe is divided as described above. It becomes easy to make it correspond with the die-cutting direction at the time of shaping | molding of a body.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  1 and 2 show a resin intake manifold 1 of a multi-cylinder engine according to an embodiment of the present invention. The intake manifold 1 is mounted on an in-line four-cylinder engine (not shown) in which four cylinders are arranged in a straight line, and has a surge tank 2 and one end communicating with the surge tank 2, while the other end Are constituted by four independent intake passages 3, 3,... Communicating with intake ports (not shown) of each cylinder.

  As shown in FIG. 1, the intake passages 3, 3,... Are juxtaposed in the longitudinal direction of the engine on the side surface where the intake port of the engine is opened, and a flange for attaching the intake manifold 1 to the engine at one end thereof. While the portion 39 is provided, the other end is connected to the surge tank 2. These intake passages 3, 3,... Extend from the flange portion 39 to the opposite side of the engine (hereinafter referred to as the anti-engine side), and then extend while curving downward, and then curve to the anti-engine side and downward. It extends. Further, the intake passages 3, 3,... Are arranged on one end side so as to be spaced apart from each other in the cylinder row direction corresponding to the interval between the intake ports of the engine, while on the other end side, the intake manifold 1 is arranged. They are provided adjacent to each other so as to gather toward the center in the cylinder row direction. The above-described curved shape of the intake passages 3, 3,... Is not limited to the above shape, and may be an arbitrary shape. However, in order to improve the intake charge efficiency, each intake passage 3 needs to have a desired intake passage length, and in order to make the intake charge efficiency and the air-fuel ratio uniform between the cylinders, each intake passage 3 3 is preferably configured such that the intake passage lengths of 3 are equal.

  As shown in FIGS. 1 and 2, the surge tank 2 has a substantially hexahedron box shape and is disposed at a position below the other end of the intake passages 3, 3. The surge tank 2 is located at a position corresponding to the center position in the cylinder row direction of the four intake passages 3, 3,. Are connected to the upper side wall 25 of the surge tank 2, and the intake passages 3, 3, ... are connected to the surge tank at the upper side wall 25. 2 communicates. Specifically, as shown in FIG. 2, the upper side wall 25 is formed with openings 3c, 3c,... That allow the intake passages 3, 3,. And the upper side wall 25 is divided into the engine side upper side wall 25a and the anti engine side upper side wall 25b on the engine side by the dividing portions 25c, 25c, so that the opening edge of each opening 3c is divided into the engine side and the counter engine side. It is divided into The engine-side upper side wall 25a is provided in a first divided body 4a described later, while the anti-engine-side upper side wall 25b is provided in a second divided body 4b described later. In addition, a throttle body (not shown) having a throttle valve is attached to the lower side wall 29 of the surge tank 2, and an intake air inlet 28 through which intake air sent from the throttle body flows into the surge tank 2 is formed. ing. As shown in FIG. 2, the opening edge Y of the intake air inlet 28 has a substantially circular shape and is positioned at the approximate center of the lower side wall 29. That is, the position where the intake air inlet 28 is provided corresponds to the center position in the cylinder row direction of the intake passages 3, 3,. Then, the intake air flowing into the surge tank 2 from the intake inlet 28 is directed to the portion between the two openings 3c, 3c on the inner side of the openings 3c, 3c,. (That is, FIG. 2 is a view seen in the intake inflow direction). Therefore, the intake air flowing from the intake air inlet 28 flows toward the center of the cylinder row direction with respect to the intake passages 3, 3,... And diffuses in the surge tank 2. As a result, the intake air is uniformly diffused to both sides in the cylinder row direction with respect to the intake passages 3, 3,. That is, the intake air uniformly diffused in each intake passage 3 is sent to the combustion chamber of each cylinder via each intake passage 3 and intake port.

  The surge tank 2 and the intake passages 3, 3,... Constitute a manifold body. As shown in FIG. 1, the manifold main body is divided into a first divided body 4 a on the engine side and a second divided body 4 b on the side opposite to the engine by dividing surfaces along the flow direction of intake air in the surge tank 2 and each intake passage 3. It is divided into The first divided body 4a and the second divided body 4b are injection molded products of resin. In addition, the first divided body 4a and the second divided body 4b are removed from the mold in the direction intersecting the divided surface at the time of molding.

  The first divided body 4 a includes a flange portion 39, an engine side passage portion 3 a of each intake passage 3, and an engine side tank portion 2 a of the surge tank 2. The intake air inlet 28 is formed in the engine side tank 2a. On the other hand, the second divided body 4 b is composed of an anti-engine side passage portion 3 b of each intake passage 3 and an anti-engine side tank portion 2 b of the surge tank 2. The first divided body 4a and the second divided body 4b are provided with a flange 41a and a flange 41b that protrude outward from the manifold body at respective divided edges formed by the divided surfaces. As shown in FIG. 2, the flange 41a and the flange 41b have welding surfaces that face each other, and the welded surfaces are vibrated and welded, whereby the first divided body 4a and the second divided body 4b Are integrally formed.

  As shown in FIGS. 1 and 2, the anti-engine side tank portion 2b of the second divided body 4b has a gas introduction pipe 44 that penetrates the anti-engine side wall 27 and protrudes inside and outside the surge tank 2. Is provided. The gas introduction pipe 44 is an introduction pipe for introducing fuel evaporative gas generated by evaporation of fuel in a fuel tank (not shown) into the surge tank 2. More specifically, the gas introduction pipe 44 is disposed at the lower end portion of the anti-engine side wall 27 such that the axis X of the gas introduction pipe 44 is orthogonal to the intake air inflow direction of the intake air flowing from the intake air inlet 28. It extends so as to pass through substantially the center of the intake air inlet 28 when viewed in the intake air inflow direction. Further, the inner opening end 44 a of the gas introduction pipe 44 located in the surge tank 2 is located in the vicinity of the opening edge Y (the two-dot chain line in FIG. 2) of the intake air inlet 28. The direction in which the axis X of the gas introduction pipe 44 extends is the same as the direction in which the second divided body 4b is punched when the second divided body 4b is injection molded. On the other hand, one end of a fuel evaporative gas hose (not shown) is attached to the outer opening end 44b of the gas introduction pipe 44 located outside the surge tank 2. The other end of the fuel evaporative gas hose communicates with a fuel evaporative gas valve that adjusts the flow rate of the fuel evaporative gas generated in the fuel tank to the surge tank 2.

  In the intake manifold 1 configured as described above, the fuel evaporative gas generated in the fuel tank is guided to the gas introduction pipe 44 and introduced into the surge tank 2 from the inner opening end 44a of the gas introduction pipe 44. Become. Further, intake air flows into the surge tank 2 from the intake air inlet 28. That is, the fuel evaporative gas introduced into the surge tank 2 from the inner opening end 44a is diffused into the surge tank 2 by the intake air flowing in from the intake air inlet 28 and mixed with the intake air, and each intake passage 3 and It is sent to the combustion chamber (not shown) of each cylinder via the intake port.

  As shown in FIG. 2, the inner opening end 44 a of the gas introduction pipe 44 protruding into the surge tank 2 is viewed from the intake inlet 28 to the surge tank 2 in the direction of intake air intake. Since it is located in the vicinity of the opening edge Y, the area of the gas introduction pipe 44 protruding into the surge tank 2 that collides with the intake air flowing into the surge tank 2 from the intake inlet 28 is suppressed. As a result, an increase in intake resistance due to intake air colliding with the gas introduction pipe 44 is suppressed, and intake charge efficiency can be improved.

  Further, as shown in FIG. 2, the axis X of the gas introduction pipe 44 is provided so as to pass through the substantially center of the intake inflow port 28 when viewed in the intake air inflow direction, thereby opening the inside of the gas introduction pipe 44. The fuel evaporative gas introduced into the surge tank 2 from the end 44 a is sent out toward the center of the air flow of the intake air flowing from the intake inlet 28, and the inner opening end 44 a of the gas introduction pipe 44 is connected to the intake inlet 28. Since the fuel evaporative gas is sent into the surge tank 2 from the inner opening end 44a by being located in the vicinity of the opening edge Y, the air flow of the intake air flowing in from the intake air inlet 28 exists. The fuel evaporative gas introduced into the surge tank 2 is easily mixed with the intake air and is sufficiently diffused in the surge tank 2 along with the air flow of the intake air.

  Therefore, according to the above-described embodiment, the gas introduction pipe 44 is provided so that the axis X thereof passes through the approximate center of the intake air inlet 28 when viewed in the intake air inflow direction of the intake air flowing from the intake air inlet 28. By configuring the inner opening end 44a to be in the vicinity of the opening edge Y (two-dot chain line in FIG. 2) of the intake inlet 28, an increase in intake resistance due to intake air colliding with the gas introduction pipe 44 is suppressed. However, the fuel evaporative gas introduced into the surge tank 2 from the inner opening end 44a can be easily mixed with the intake air and can be uniformly diffused in the surge tank 2 with respect to the intake air. As a result, the fuel evaporative gas is fed into the combustion chamber of each cylinder in a state of being uniformly mixed with the intake air, so that the air-fuel ratio of each cylinder can be made uniform.

  Further, the gas introduction pipe 44 is provided close to the lower end portion of the anti-engine side wall 27, that is, the lower side wall 29 of the surge tank 2, so that the inner opening end 44 a of the gas introduction pipe 44 is connected to the surge tank from the intake inlet 28. Therefore, the fuel evaporative gas can be diffused in a wider range in the surge tank 2.

  Further, the intake manifold 1 has an intake air inlet 28 disposed at a position corresponding to the center position in the cylinder row direction of the four intake passages 3, 3,. In order to allow intake air to flow in the direction of the central position, the intake air is uniformly diffused in the surge tank 2. That is, by configuring the intake air inlet 28 and the intake air inflow direction so that the intake air is uniformly diffused in the surge tank 2, the intake air is introduced into the surge tank 2 by the gas introduction pipe 44 and mixed with the intake air. The fuel evaporative gas can be diffused more uniformly into each intake passage 3 to make the air-fuel ratio of each cylinder more uniform.

  Furthermore, by making the direction of the axis X of the gas introduction pipe 44 coincide with the die cutting direction at the time of injection molding of the second divided body 4b, it protrudes into and out of the manifold body, and the axis X is orthogonal to the intake air inflow direction. The second divided body 4b having the gas introduction pipe 44 provided can be easily molded from resin. Here, the molds of the first divided body 4a and the second divided body 4b are removed in a direction intersecting with the divided surface at the time of injection molding. The gas introduction pipe 44 has an axis X extending in a direction perpendicular to the intake air inflow direction. That is, by dividing the manifold main body along the flow direction of the intake air, the axis X of the gas introduction pipe 44 extends in a direction that also intersects the dividing surface. Therefore, the axis X is used as the second divided body 4b. It becomes easy to make it correspond to the die cutting direction at the time of molding.

<< Other Embodiments >>
The present invention may be configured as follows with respect to the above embodiment.

  That is, in the above embodiment, the fuel evaporative gas is adopted as the gas introduced into the surge tank 2 by the gas introduction pipe 44, but is not limited to this. For example, EGR gas or blow-by gas may be introduced.

  In the above embodiment, the intake inlet 28 is provided in the first divided body 4a and the gas introduction pipe 44 is provided in the second divided body 4b. However, the present invention is not limited to this. That is, the intake inlet 28 may be provided in the second divided body 4b, and the gas introduction pipe 44 may be provided in the first divided body 4a, and both the intake inlet 28 and the gas introduction pipe 44 may be provided in the first divided body 4a or You may provide in either one of the 2nd division body 4b. Furthermore, in the above embodiment, the intake inlet 28 is formed on the lower side wall 29 of the surge tank 2, but is not limited to this, and is formed on other walls forming the surge tank 2, such as the anti-engine side wall 27. May be. Similarly, the gas introduction pipe 44 is formed on the anti-engine side wall 27 of the surge tank 2, but may be formed on other walls forming the surge tank 2 such as the lower side wall 29.

  Furthermore, in the said embodiment, although the manifold main body is comprised by the 1st division body 4a and the 2nd division body 4b, it is not restricted to this. That is, when viewed in the intake air inflow direction of the intake air flowing in from the intake air inlet 28, the gas introduction pipe 44 is provided so that the axis X thereof passes through the substantial center of the intake air inlet 28, and the inner opening end 44a thereof is the intake air. As long as it is configured to be positioned in the vicinity of the opening edge Y of the inflow port 28, the manifold body may be divided into three or more.

  Furthermore, in the above-described embodiment, the engine in which the intake port opens on the side surface of the engine is targeted, and the intake manifold 1 is configured to be attached to the side surface of the engine, but is not limited thereto. For example, the engine may have a cylinder extending in the horizontal direction and the piston in the cylinder slides in the horizontal direction. In such a case, the intake port is open on the upper surface of the engine, and the intake manifold 1 is The surge tank 2 and the intake passages 3, 3, ... are attached to the upper surface of the engine in a state where they are aligned in a substantially horizontal direction.

It is a perspective view of the intake manifold which concerns on this embodiment. It is sectional drawing in the AA of FIG.

Explanation of symbols

1 Intake manifold 2 Surge tank (manifold body)
28 Intake inlet 3 Intake passage (manifold body)
4a 1st division body 4b 2nd division body 44 Gas introduction pipe 44a Inner opening end (opening end)
X axis Y Open edge

Claims (2)

Fuel generated in the fuel tank and a manifold body composed of a surge tank having an intake inlet, one end communicating with the intake port of the internal combustion engine and the other end communicating with the surge tank An intake manifold for an internal combustion engine comprising a gas introduction pipe for introducing at least one of evaporative gas, EGR gas, and blow-by gas into the surge tank,
The gas introduction pipe is provided in the surge tank and extends to the inside of the surge tank so that its axial line passes through the approximate center of the intake inlet, as viewed in the intake inflow direction to the surge tank. An intake manifold for an internal combustion engine, wherein an opening end located in the surge tank and introducing the gas into the surge tank is positioned in the vicinity of an opening edge of the intake inlet. The intake manifold of the internal combustion engine according to claim 1,
The manifold body is a resin molded product composed of a first divided body and a second divided body that are divided along the flow direction of intake air,
The gas introduction pipe is formed of resin integrally with the first divided body or the second divided body, and the axis thereof is provided so as to extend in the same direction as the die cutting direction at the time of molding of the integrally molded divided body. An intake manifold for an internal combustion engine.

Images