JP2023111494A - Suction device for engine - Google Patents

Abstract

An intake system for an engine is provided, which can suppress condensed water accumulated in the lower part of a surge tank due to air flow from being sent into a cylinder at once, thereby suppressing misfiring in the cylinder. . An intake system for an engine includes an intake manifold. The intake manifold 6 has a plurality of runners, a surge tank 62 and an intake introduction passage 61 . Surge tank 62 has a space in which a plurality of runners are assembled, and is provided such that the runner introduction ports of the plurality of runners are aligned along a predetermined direction. The intake air introduction passage 61 is a passage for introducing air into the surge tank 62 . A side wall inner surface 62h of the surge tank 62 is provided with a deflection base portion 62i that deflects the flow of air flowing along the side wall inner surface 62h toward the runner inlet after passing above the lower wall inner surface 62a of the surge tank 62. is provided. [Selection drawing] Fig. 5

Description

The present invention relates to an intake system for an engine.

Some vehicle engines are equipped with an EGR (Exhaust Gas Recirculation) device that recirculates a portion of exhaust gas to intake air. By adding the EGR device in this way, it is possible to suppress an excessive rise in combustion gas temperature, suppress the generation of nitrogen oxides (NOx), and reduce the pumping loss during intake.

By the way, fresh air and EGR gas sent from the intake manifold to each cylinder of the engine body contain moisture. The moisture contained in the fresh air and EGR gas may accumulate as condensed water in the lower part of the intake manifold. If the condensed water accumulated in this way is sent into the cylinder, it is conceivable that the cylinder may misfire.

In Patent Document 1, a receiving portion provided at an inlet of a surge tank for receiving condensed water and a surge for gradually dropping the received condensed water to the lower part of the surge tank while guiding the received condensed water in the cylinder arrangement direction. An intake manifold is disclosed having a guide surface provided in the tank. The intake manifold disclosed in Patent Document 1 is designed to prevent a large amount of condensed water from being sent to a specific cylinder at once by adopting the configuration described above.

JP 2008-286069 A

However, with the technique disclosed in Patent Document 1, the flow of fresh air or EGR gas scoops up the condensed water that has accumulated in the lower part of the surge tank, and a large amount of condensed water is sent into the cylinder at once. Conceivable.

Since the fresh air sent into the intake manifold also contains moisture, it is conceivable that even in an engine without an EGR device, the same problem of misfire due to condensed water being sent into the cylinders may occur.

The present invention provides an intake system for an engine that can suppress condensed water accumulated in the lower part of a surge tank due to air flow from being sent into a cylinder all at once, thereby suppressing misfiring in the cylinder. intended to

An intake device for an engine according to one aspect of the present invention includes an engine body and an intake manifold. The engine body has a plurality of cylinders and a cylinder head formed with an intake port connected to each of the plurality of cylinders. Air to the plurality of intake ports in the engine body passes through the intake manifold.

The intake manifold has a plurality of independent intake passages, a surge tank, and an intake introduction passage. The plurality of independent intake passages are passages arranged along the direction of the row of cylinders in the engine body and connected to each of the plurality of intake ports. The surge tank has a space in which the plurality of independent intake passages are assembled, and is a portion provided so that the openings of the plurality of independent intake passages are aligned along a predetermined direction. The intake air introduction passage is a passage for introducing air into the surge tank.

In the engine air intake device according to this aspect, the surge tank has a deflection table portion provided on the inner surface of the side wall facing the side wall having the plurality of openings across the space. The deflection table section deflects the flow of air flowing along the inner surface of the side wall so that it passes above the inner surface of the lower wall of the surge tank and flows toward at least a portion of the plurality of openings.

In the engine intake device according to the above aspect, since the deflecting base portion is provided on the inner surface of the side wall of the surge tank in the intake manifold, the air flowing along the inner surface of the side wall is directed upward from the inner surface of the lower wall. can be passed through. As a result, in the intake device for the engine according to the aspect described above, it is possible to prevent the condensed water accumulated on the inner surface of the lower wall of the surge tank from being introduced into the independent intake passage all at once. Therefore, in the engine intake device according to the aspect described above, misfiring in the cylinder can be suppressed by suppressing the introduction of a large amount of condensed water into the cylinder at once.

In the intake device for an engine according to the aspect described above, the intake introduction passage is formed to extend from one end of the surge tank toward the other end along the predetermined direction. It may be communicated with the space of the surge tank, and the intake introduction passage and the space of the surge tank may be partitioned by a partition except for the communicating portion on the other end side.

In the intake system for the engine according to the above aspect, since the partition is provided between the intake introduction passage and the space of the surge tank, it is possible to secure the passage length of the intake introduction passage. Condensed water accumulated on the inner surface of the lower wall of the surge tank may be easily scooped up due to changes in the air flow within the tank.

However, in the engine intake device according to the above aspect, since the deflection base is provided on the inner surface of the side wall of the surge tank, the condensed water accumulated on the inner surface of the lower wall of the surge tank is prevented from being scooped up by the air flow. can do. Therefore, the engine intake device according to the above aspect is suitable for suppressing misfires in cylinders caused by condensed water.

In the intake device for an engine according to the aspect described above, the deflection base portion is provided so as to protrude from the inner surface of the opposing side wall toward the plurality of openings in the range facing the plurality of openings in the predetermined direction. Moreover, the height of the protrusion toward the space may be gradually increased from the top to the bottom.

In the intake device for the engine according to the above aspect, the deflection base portion is provided on the inner surface of the side wall of the surge tank so that the protrusion height toward the space side gradually increases from the top to the bottom. To ensure that the air flowing along the inner surface passes above the inner surface of the lower wall.

In addition, in the engine intake device according to the above aspect, since the deflection base portion in the surge tank is provided in a region including a range facing the plurality of openings (openings connected to the plurality of independent intake passages), On the other hand, it is possible to avoid a situation in which a large amount of condensed water is introduced into the cylinder at once.

In the intake device for an engine according to the aspect described above, the surge tank is provided on the deflection table, and the air flowing through the space of the surge tank from the other end to the one end is directed through the plurality of openings. It may further comprise a deflection protrusion that deflects toward.

Since the engine air intake device according to the above aspect further includes the deflection protrusion on the deflection base, the air that has flowed along the inner surface of the side wall is allowed to pass above the inner surface of the lower wall while passing through each opening. can guide you with certainty.

In the engine air intake device according to the above aspect, the surge tank is provided on the inner surface of the lower wall of the surge tank so as to extend toward the inner surface of the opposing side wall from each of the portions between the adjacent openings. It may further have a plurality of ribs attached to it.

In the engine air intake device according to the aspect described above, the plurality of ribs are provided on the inner surface of the lower wall of the surge tank so as to extend from the portions between the openings of the plurality of independent intake passages. condensed water movement is regulated by the ribs. As a result, in the engine intake device according to the above aspect, the condensed water accumulated on the inner surface of the lower wall of the surge tank can be suppressed from being biased toward the downstream side in the direction of air flow, and the air in the predetermined direction can be prevented. It is possible to prevent a large amount of condensed water from being suddenly introduced into the independent intake passage having an opening on the downstream side in the flow direction of the cylinder, thereby suppressing misfiring in the cylinder to which the independent intake passage is connected.

In the intake device for an engine according to the aspect described above, the intake air introduction passage is directed toward the inner surface of the lower wall at the portion communicating with the space of the surge tank in the central portion in the predetermined direction. Communicating with the space, the deflection table section has the plurality of openings from the inner surface of the opposing side wall so as to cover a portion above the inner surface of the lower wall in a region including the central portion in the predetermined direction. It may be provided so as to protrude toward a part of the.

In the intake device for an engine according to the above aspect, the deflection base portion is provided in the region including the central portion in the predetermined direction so as to cover a portion of the upper portion of the inner surface of the lower wall and protrude toward a portion of the plurality of openings. is provided, the air introduced into the surge tank from the intake air introduction passage collides with the deflection base and is dispersed in the predetermined direction (the direction of flow is deflected). Since the flow of air dispersed in the predetermined direction can pass above the inner surface of the lower wall of the surge tank, the condensed water accumulated on the inner surface of the lower wall is removed from the central portion in the predetermined direction. is restrained from being introduced into the independent intake passage through an opening provided in the air intake passage. Therefore, in the engine intake device according to the above aspect, a large amount of condensed water is introduced at once into a specific cylinder (in particular, a cylinder connected to an independent intake passage having an opening in the center portion of the surge tank in the predetermined direction). It is possible to suppress misfires caused by

In the engine air intake device according to the above aspect, the surge tank is provided on the inner surface of the lower wall of the surge tank on both sides of the deflection table portion in the predetermined direction, and the openings are adjacent to each other. It may further have two ribs extending from each of the portions between and toward the inner surface of the opposing side walls.

In the intake device for an engine according to the above aspect, the intake introduction passage communicates with the space of the surge tank so as to point toward the inner surface of the lower wall of the surge tank at the central portion in the predetermined direction. The flow of the air introduced into the surge tank is deflected in the predetermined direction. When the flow of air above the condensed water accumulated on the inner surface of the lower wall of the surge tank is from the central portion to the ends in the predetermined direction, the condensed water also moves from the central portion to the ends, It is conceivable that the condensed water on the inner surface of the bottom wall of the surge tank is more concentrated at the ends than at the center.

However, in the intake device for the engine according to the above aspect, two ribs are provided on the inner surface of the lower wall at the portions on both sides where the deflection base portion is provided in the predetermined direction. Condensate movement in the direction of is restricted. Therefore, in the intake device for an engine according to the aspect described above, it is possible to suppress the concentration of condensed water at both ends of the surge tank in the predetermined direction. It is possible to suppress introduction of a large amount of condensed water at once.

In the intake device for an engine according to the above aspect, the intake manifold is joined together in a direction in which the inner surface of the side wall provided with the plurality of openings and the inner surface of the side wall provided with the deflection table portion face each other. Thus, the space of the surge tank may be configured by joining a plurality of members including a first member and a second member that configure the space.

In the engine intake system according to the above aspect, since the intake manifold is formed by joining a plurality of members including the first member and the second member, the inside of the surge tank has a complicated internal structure having a deflector on the inner surface of the side wall. It is possible to easily manufacture a structural intake manifold.

In the intake device for an engine according to the aspect described above, the plurality of openings may be provided such that the lower end portions thereof are positioned above the inner surface of the lower wall of the surge tank.

In the engine intake device according to the above aspect, each opening of the independent intake passage is provided so as to be positioned above the inner surface of the lower wall of the surge tank. It is possible to suppress a situation in which condensed water undesirably flows from the air intake passages to the independent intake passages. As a result, misfires in the cylinders can be suppressed when the engine is restarted.

In the engine intake device according to the above aspect, each of the plurality of independent intake passages may have a portion extending upward from the opening.

In the engine intake system according to the above aspect, each of the independent intake passages has a portion extending upward from the opening, so that condensed water remaining in the independent intake passages is returned to the surge tank when the engine is stopped. be Therefore, it is more suitable for suppressing misfiring in a cylinder when the engine is restarted.

In the engine intake device according to the aspect described above, an EGR passage for introducing EGR gas may be connected to the intake manifold.

In the engine intake device according to the above aspect, since the EGR passage is connected to the intake manifold, it is possible to suppress an excessive rise in the temperature of the combustion gas and suppress the generation of nitrogen oxides (NOx). It is possible to reduce the pumping loss at times. On the other hand, the moisture contained in the EGR gas condenses and the condensed water generated from the EGR gas accumulates on the inner surface of the lower wall of the surge tank. It is possible to prevent a large amount of condensed water from being scooped up and introduced into the opening of the independent intake passage all at once. Therefore, in the intake device for the engine according to the above aspect, by connecting the EGR passage to the intake manifold, it is possible to obtain the effects described above and to suppress misfiring in the cylinder due to the condensed water being sent. .

In the engine intake device according to each of the above aspects, the condensed water accumulated in the lower part of the surge tank due to the air flow is suppressed from being sent into the cylinder at once, thereby suppressing misfiring in the cylinder. can be done.

1 is a schematic diagram showing the configuration of an engine according to a first embodiment; FIG. FIG. 3 is a perspective view showing the external configuration of an intake manifold; FIG. 3 is a perspective view showing the external configuration of an intake manifold; FIG. 3 is a cross-sectional view showing the configuration of a cross section taken along line IV-IV in FIG. 2; FIG. 3 is a cross-sectional view showing the configuration of the cross section taken along the line VV in FIG. 2; It is a perspective view which shows the structure of a base member. FIG. 4 is a perspective view showing the configuration of a center member; (a) is a sectional view showing the state of air flow and condensed water in an intake manifold according to the embodiment; (b) is a sectional view showing the state of air flow and condensed water in an intake manifold according to a comparative example; It is a diagram. 4 is a graph showing the cumulative displacement amount for each cylinder in each of the example and comparative example 1. FIG. 4 is a graph showing overall pressure loss in each of Example and Comparative Examples 1 and 2. FIG. FIG. 7 is a perspective view showing a partial configuration of an intake manifold provided in an engine intake system according to a second embodiment; Fig. 3 is a front view showing the intake manifold with the cover member removed; FIG. 12 is a cross-sectional view showing the configuration of a cross section taken along line XIII-XIII in FIG. 11; 12 is a cross-sectional view showing the configuration of the XIV-XIV line cross section in FIG. 11; FIG. FIG. 4 is a perspective view showing the flow of air in the surge tank of the intake manifold; FIG. 11 is a top view showing the external configuration of an intake manifold provided in an intake system for an engine according to a third embodiment; FIG. 11 is a side view showing the external configuration of an intake manifold provided in an intake device for an engine according to a third embodiment; FIG. 4 is an exploded perspective view showing the configuration of the intake manifold, and ribs and deflection bases provided on the inner surface of the lower wall of the surge tank.

EMBODIMENT OF THE INVENTION Below, embodiment of this invention is described, considering drawing into consideration. In addition, the form described below is an example of the present invention, and the present invention is not limited to the following forms except for its essential configuration.

[First embodiment]
1. Configuration of Engine 1 The configuration of the engine 1 according to the first embodiment will be described with reference to FIG. Note that the engine 1 shown in FIG. 1 is an engine mounted on a vehicle, and the illustration of a part of its configuration is omitted in FIG.

As shown in FIG. 1, the engine 1 includes an engine body 2, an intake device 3, an exhaust device 4, a turbocharger 5, an HP-EGR (High Pressure Exhaust Gas Recirculation) section 8, and an LP-EGR. (Low Pressure Exhaust Gas Recirculation) section 9; The engine body 2 has a plurality of cylinders (for example, four cylinders) 2a.

The intake device 3 has an intake passage 30 , an air cleaner 31 , an intercooler 32 , a throttle valve 33 and an intake manifold 6 . The intake passage 30 is connected to the intake manifold 6 via an air cleaner 31 , an intercooler 32 , a throttle valve 33 and a compressor 51 of the turbocharger 5 . Fresh air (air) is taken in by an air cleaner 31, pressurized by a compressor 51, cooled by an intercooler 32, and sent to an intake manifold 6 through a throttle valve 33, as indicated by an arrow A1. Regarding the intake passage 30, the part on the permanent side of the compressor 51 may be referred to as an upstream part 30a, and the part on the downstream side of the compressor 51 may be referred to as a downstream part 30b.

The intake manifold 6 has an intake introduction passage 61, a surge tank 62, and a plurality of runners (independent intake passages) 62-66. The intake introduction passage 61 has one end connected to the intake passage 30 via the throttle valve 33 and the other end connected to the surge tank 62 . Each of the plurality of runners 62 to 66 has one end connected to the surge tank 62 and the other end connected to an intake port formed in the cylinder head of the engine body 2 . A detailed structure of the intake manifold 6 will be described later.

The exhaust device 4 has an exhaust manifold 7 , an exhaust passage 40 and a silencer 41 . The exhaust manifold 7 has one end connected to an exhaust port formed in the cylinder head of the engine body 2 and the other end connected to an exhaust passage 40 . The exhaust passage 40 connects the exhaust manifold 7 and the silencer 41 via the turbine 52 of the turbocharger 5 . Exhaust gas discharged from the exhaust port of the engine main body 2 applies rotational driving force to the turbine 52, and is then reduced in pressure and temperature by the silencer 41 before being discharged outward (arrow A2). Regarding the exhaust passage 40, the portion upstream of the turbine 52 may be referred to as an upstream portion 40a, and the portion downstream of the turbine 52 may be referred to as a downstream portion 40b in the flow direction of the exhaust gas.

The HP-EGR section 8 has an EGR passage 81 and an EGR valve 82 . The EGR passage 81 has one end connected to an exhaust port formed in the cylinder head of the engine body 2 and the other end connected to the intake introduction passage 61 of the intake manifold 6 . In this embodiment, the other end of the EGR passage 81 is connected to the intake introduction passage 61 of the intake manifold 6. may be connected to

The EGR valve 82 adjusts the amount of exhaust gas recirculated from the exhaust port of the engine body 2 to the intake introduction passage 61 .

The LP-EGR section 9 has an EGR passage 91 , an EGR cooler 92 and an EGR valve 93 . The EGR passage 91 is provided to connect the downstream portion 40 b of the exhaust passage 40 and the upstream portion 30 a of the intake passage 30 . The EGR cooler 92 is provided to cool the exhaust gas flowing through the EGR passage 91 . The EGR valve 93 adjusts the amount of exhaust gas recirculated from the downstream portion 40 b of the exhaust passage 40 to the upstream portion 30 a of the intake passage 30 .

2. Configuration of Intake Manifold 6 The configuration of the intake manifold 6 will be described with reference to FIGS. 2 to 5. FIG.

As shown in FIGS. 2 and 3, the intake manifold 6 is configured by joining a base member (first member) 6A, a center member (second member) 6B, and a cover member 6C. . In this embodiment, the base member 6A, the center member 6B, and the cover member 6C are each made of a resin material. It should be noted that the number of members constituting the intake manifold 6, the shape and constituent materials of each member, and the like can be changed as appropriate.

The intake air introduction passage 61 is composed of a cylindrical pipe and has an opening (introduction port) 61a to which the throttle valve 33 is connected at one end. As shown in FIGS. 4 and 5, the other end of the intake introduction passage 61 communicates with the space of the surge tank 62 . A space between the intake air introduction passage 61 and the surge tank 62 is partitioned by a partition wall 61b except for a portion where the air intake introduction passage 61 and the space between the surge tank 62 are communicated.

As shown in FIGS. 2 to 5, the surge tank 62 is arranged below the portion where the intake introduction passage 61 is formed. As shown in FIGS. 4 and 5, the above-described partition wall 61b is provided so as to partition the space of the intake air introduction passage 61 and the surge tank 62 in the vertical direction.

As shown in FIG. 2, the four runners 63 to 66 are each formed to extend vertically and are arranged along the direction in which the intake air introduction passage 61 extends. As shown in FIG. 3, each of the runners 63 to 66 is arranged so that the upper part thereof covers the upper part of the intake introduction passage 61, and is connected to an intake port formed in the cylinder head of the engine body 2 at its end. Runner outlets 63a, 64a, 65a and 66a are provided.

As shown in FIG. 4, each of the runners 63 to 66 has openings (runner inlets) 63b, 64b, 65b, 66b communicating with the space of the surge tank 62 at its lower portion. Runner introduction ports 63 b , 64 b , 65 b , 66 b of runners 63 to 66 are provided in side wall 62 j surrounding the space in surge tank 62 . Note that the runner introduction ports 63b, 64b, 65b, and 66b in this embodiment correspond to "openings in a plurality of independent intake passages", and the direction in which the runner introduction ports 63b, 64b, 65b, and 66b are arranged in FIG. direction”.

As shown in FIGS. 2 and 5, each of runners 63-66 has a portion extending upward from runner introduction ports 63b, 64b, 65b and 66b. Also, as shown in FIGS. 4 and 5, the lower end portions of the runner introduction ports 63b, 64b, 65b, and 66b are positioned above the lowest height level of the inner surface 62a of the lower wall of the surge tank 62. is provided as follows.

As shown in FIG. 4, a rib 62b is formed along the lower wall inner surface 62a from a portion (intermediate portion) 62e between the runner introduction port 63b and the runner introduction port 64b toward the front side of FIG. Similarly, a rib 62c is formed along the inner surface 62a of the lower wall toward the front side of the paper surface of FIG. A rib 62d is formed along the lower wall inner surface 62a from a portion (intermediate portion) 62g between the introduction port 66b and toward the front side of the paper surface of FIG. In this embodiment, the height of the ribs 62b-62d from the lower wall inner surface 62a is the same for the three ribs 62b-62d. However, it is also possible to change the heights of the three ribs 62b to 62d.

As shown in FIGS. 4 and 5, the surge tank 62 has an inner surface of a side wall (side wall 62j) opposite to a side wall 62j provided with the runner introduction ports 63b, 64b, 65b, and 66b across the space of the surge tank 62. In the inner surface 62h, a pedestal-like deflection base portion 62i is formed at the lower portion thereof so as to protrude toward the inner side of the space. The deflection table portion 62i is provided so as to cover the entire range facing the runner introduction ports 63b, 64b, 65b, 66b in the predetermined direction (the direction perpendicular to the plane of FIG. 5). The deflection table 62i deflects the air mixed in the space of the surge tank 62 so as to pass above the lowest portion of the lower wall inner surface 62h and guide it to the runner inlets 63b, 64b, 65b, 66b ( Arrow B). In this embodiment, the deflection base portion 62i is formed such that the height of the protrusion toward the space (toward the side wall 62j) gradually increases from the top to the bottom.

3. Formation of surge tank 62 by joining base member 6A and center member 6B As described above, in the present embodiment, intake manifold 6 is formed by joining base member 6A, center member 6B, and cover member 6C. Among them, the surge tank 62 is formed by the base member 6A and the center member 6B. Formation of the surge tank 62 by joining the base member 6A and the center member 6B will be described with reference to FIGS. 6 and 7. FIG.

As shown in FIG. 6, the base member 6A has a portion forming part of the intake air introduction passage 61 and a portion forming part of the surge tank 62 as well. As shown in FIG. 6, the inner space portion of the base member 6A is open to the front side of the drawing when the center member 6B is not joined.

The base member 6A includes the entire deflection table portion 62i provided on the side wall inner surface 62h, the base side portions 62b1, 62c1, and 62d1 which are each part in the longitudinal direction of the ribs 62b, 62c, and 62d, and the intake air introduction passage 61. and a base side portion 61b1 that is a part of the partition wall 61b that partitions between and the surge tank 62 is formed. A base member 6A including these portions 61b1, 62i, 62b1, 62c1 and 62d1 is integrally formed from a resin material.

As shown in FIG. 7 , the center member 6B has a portion forming the remaining portion of the intake air introduction passage 61 and a portion forming the remaining portion of the surge tank 62 . As shown in FIG. 7, the inner space of the center member 6B is also open to the front side of the drawing when the base member 6A is not joined.

The center member 6B includes center side portions 62b2, 62c2, and 62d2, which are the remaining portions in the longitudinal direction of the ribs 62b, 62c, and 62d, and the remaining portion of the partition wall 61b that partitions the intake air introduction passage 61 and the surge tank 62. A center side portion 61b2 is formed. The end surfaces of these portions 61b2, 62b2, 62c2, 62d2 are joined to the base side portions 61b1, 62b1m, 62c1, 62d1 of the base member 6A when the base member 6A and the center member 6B are joined.

Runner introduction ports 63b, 64b, 65b, and 66b are opened in the side wall 62j of the center member 6B.

Also, the center member 6B, including the center side portions 61b2, 62b2, 62c2, 62d2, is integrally formed from a resin material.

4. Reduction of Condensed Water Introduction Amount to Runner Inlet Ports 63b, 64b, 65b, 66b by Deflection Base 62i This prevents a large amount of condensed water from being introduced into the runner introduction ports 63b, 64b, 65b, and 66b all at once. This will be described with reference to FIGS. 8 and 9. FIG. Incidentally, FIG. 8(a) schematically shows the flow of air and the state of condensed water in the intake manifold 6 according to an example having the same configuration as the present embodiment, and FIG. 4 schematically shows the flow of air and the state of condensed water in an intake manifold 900 according to Modification 1, which does not have a deflection table.

As shown in FIG. 8(a), when the engine body 2 is driven, fresh air and EGR gas (hereinafter referred to as "fresh air, etc.") are introduced into the surge tank 62 through the intake passage. It's coming. A part of the fresh air and the like introduced into the surge tank 62 flows downward along the side wall inner surface 62 h of the surge tank 62 .

Further, in the intake manifold 6 according to the embodiment, since a partition is provided between the intake introduction passage and the surge tank 62, fresh air and EGR gas are It flows toward the side where the introduction port) 63b is provided (see FIG. 4, etc.). Here, the runner introduction port 63b is changed to the #1 runner introduction port 63b, the runner introduction port 64b is changed to the #2 runner introduction port 64b, the runner introduction port 65b is changed to the #3 runner introduction port 65b, and the runner introduction port 66b is changed to the #4 runner introduction port 66b. called.

Returning to FIG. 8(a), between the three ribs 62b, 62c, 62d provided on the inner surface 62a of the lower wall of the surge tank 62 (only the rib 62c is shown in FIG. 8(a)). , the condensed water LQ is accumulated. The height positions of the top portions of the ribs 62b, 62c, and 62d are defined based on the estimated amount of condensed water accumulated in the surge tank 62, which is grasped at the design stage of the intake manifold 6. FIG.

As described above, since the surge tank 62 of the intake manifold 6 is provided with the deflection base portion 62i on the inner surface 62h of the side wall, fresh air or the like flows above the inner surface 62a of the lower wall (arrow C1 ), making it difficult to scoop up the condensed water accumulated on the inner surface 62a of the lower wall. Therefore, in the intake manifold 6 according to the embodiment, it is suppressed that a large amount of condensed water LQ is sent into the runner introduction ports 63b, 64b, 65b, 66b at once.

In the intake manifold 6 according to the embodiment, the ribs 62b, 62c, and 62d are provided on the inner surface 62a of the lower wall of the surge tank 62, so that the ribs 62b, 62c, and 62d condense air with the flow of fresh air. The movement of the water LQ toward the side where the #1 runner introduction port 63b is provided is suppressed. This also prevents a large amount of condensed water LQ from being introduced all at once from the #1 runner introduction port 63b and the #2 runner introduction port 64b.

Therefore, in the intake device 3 of the engine 1 having the intake manifold 6 according to the embodiment, a large amount of condensed water LQ is prevented from being sent to a specific cylinder 2a all at once, and misfiring in the cylinder 2a is suppressed. be.

On the other hand, as shown in FIG. 8(b), in the intake manifold 900 of Comparative Example 1 as well, when the engine body is running, part of the fresh air introduced into the surge tank 962 through the intake introduction passage is It flows from top to bottom along 962h. In the intake manifold 900 of Comparative Example 1, since the deflection base portion is not provided on the side wall inner surface 962h of the surge tank 962, the fresh air flowing along the side wall inner surface 962h reaches the lower wall inner surface 962a where the condensed water LQ is accumulated. (arrow C2). Therefore, in intake manifold 900 of Comparative Example 1, a large amount of condensed water LQ accumulated on lower wall inner surface 962a of surge tank 962 is scooped up and introduced into runner inlet 965b (arrow C3).

In addition, in the intake manifold 900 of Comparative Example 1, since ribs are not provided on the inner surface 962a of the lower wall of the surge tank 962, the fresh air flowing in the above-described predetermined direction directs the flow toward the side where the #1 runner inlet is provided. As a result, the condensed water LQ moves in the surge tank 962, causing unevenness in the condensed water LQ. For this reason, a large amount of condensed water LQ is sent into the #1 and #2 runners at once from the #1 runner introduction port and the #2 runner introduction port, and misfires may occur in the cylinders to which these runners are connected.

As shown in FIG. 9, in each of Example and Comparative Example 1, the amount of condensed water LQ introduced into the #1 to #4 runner inlets was investigated. In the graph shown in FIG. 9, the amount of condensed water LQ introduced from the #1 runner inlet in Comparative Example 1 is expressed as a relative value assuming "100".

As shown by the dashed line in FIG. 9, in Comparative Example 1, the amount of condensed water LQ introduced from the #1 and #2 runners is greater than the amount of condensed water LQ introduced from the #3 and #4 runner inlets. There are many. In particular, the amount of condensed water LQ introduced from the #1 runner inlet is ten times or more the amount of condensed water LQ introduced from the #4 runner inlet, as indicated by arrow D2.

On the other hand, as shown by the solid line in FIG. 9, in the embodiment, the amount of condensed water LQ introduced from the #1 to #3 runner inlets 63b, 64b, 65b is larger than the amount of condensed water LQ introduced from the #4 runner inlet 88b. Although the amount of condensed water LQ introduced is large, the amount of condensed water LQ introduced from the #3 runner inlet 65b and, as indicated by arrow D1, the amount of condensed water LQ introduced from the #4 runner inlet 66b It is suppressed to about 7.6 times compared to the amount. Accordingly, in the embodiment in which the surge tank 62 is provided with the deflector pedestal 62i on the side wall inner surface 62h and the lower wall inner surface 62a is provided with the ribs 62b to 62d, the #1 to #4 runner introduction ports 63b, 64b, 65b, 66b It can be seen that the bias in the introduction amount of the condensed water LQ to the can be suppressed.

5. Deflection Base 62i and Ribs 62b to 62d and Pressure Loss The effect of the deflection base 62i and ribs 62b to 62d on the surge tank 62 on pressure loss will be described with reference to FIG. In FIG. 10, Comparative Example 1 and Example are the same as those described with reference to FIGS. On the other hand, this is an example in which the surge tank 62 is not provided with the deflection base portion 62i.

As shown in FIG. 10, when the pressure loss of Comparative Example 1 is assumed to be "100", the Example is about 93 and the Comparative Example 2 is about 94. From this, as described with reference to FIG. 8B, in Comparative Example 1, the surge tank 962 does not have the deflecting table portion and the rib, so that the condensed water LQ accumulated in the surge tank 962 flows in the predetermined direction. It is considered that the condensed water LQ was scooped up by fresh air or the like, resulting in an increase in pressure loss.

In Comparative Example 2, since the surge tank has ribs, the condensed water LQ accumulated in the surge tank is less likely to be biased in the predetermined direction. considered to be suppressed.

On the other hand, in the embodiment, since the surge tank 62 has the deflection base portion 62i and the ribs 62b to 62d, the pressure loss is kept lower than in the comparative examples 1 and 2 (arrows E1 and E2).

Here, in the example, the pressure loss is kept lower than in the comparative example 2, though slightly (arrow F2). It can be seen that, in the embodiment, by providing the deflection base portion 62i at the lower portion of the side wall inner surface 62h of the surge tank 62, fresh air or the like hits the vicinity of the top portions of the ribs 62b to 62d and pressure loss is suppressed. .

6. Effect In the intake device 3 of the engine 1 according to the present embodiment, since the deflection base portion 62i is provided on the inner surface 62h of the side wall of the surge tank 62 in the intake manifold 6, the air flowing along the inner surface 62h of the side wall (Arrow C1 in FIG. 8(a)) can be made to pass above the inner surface 62a of the lower wall. As a result, in the intake manifold 6 of the intake device 3, it is possible to prevent the condensed water LQ accumulated on the inner surface 62a of the lower wall of the surge tank 62 from being introduced into the runners 63-66 all at once. Therefore, in the engine 1 including the intake device 3, misfiring in the cylinder 2a can be suppressed by suppressing the introduction of a large amount of the condensed water LQ into the cylinder 2a at once.

Further, in the intake device 3 of the engine 1 according to the present embodiment, the intake manifold 6 is provided with the partition wall 61b between the space of the intake introduction passage 61 and the surge tank 62, so that the passage length of the intake introduction passage 61 is ensured. However, it is conceivable that the condensed water LQ accumulated on the inner surface 62a of the lower wall of the surge tank 62 can be easily scooped up due to changes in the air flow in the surge tank 62 by increasing the passage length.

However, in the intake device 3 of the engine 1 according to the present embodiment, in the intake manifold 6, the deflecting base portion 62i is provided on the side wall inner surface 62h of the surge tank 62, so that the air accumulated on the lower wall inner surface 62a of the surge tank 62 It is possible to suppress the condensed water LQ from being scooped up by the air flow. Therefore, in the engine 1 including the intake device 3, this is suitable for suppressing misfires in the cylinder 2a caused by the condensed water LQ.

Further, in the intake device 3 of the engine 1 according to the present embodiment, in the intake manifold 6, the inner surface 62h of the side wall of the surge tank 62 is configured such that the protrusion height toward the space side gradually increases from the top to the bottom. By providing the deflection base portion 62i, the air flowing along the side wall inner surface 62h (arrow C1 in FIG. 8A) can be reliably passed above the lower wall inner surface 62a.

Further, in the intake system 3 of the engine 1, in the intake manifold 6, the deflection base portion 62i of the surge tank 62 is provided in a range facing the plurality of runner introduction ports 63b, 64b, 65b, 66b. It is possible to avoid a situation in which a large amount of condensed water LQ is introduced into the cylinder 2a at once.

Further, in the intake device 3 of the engine 1 according to the present embodiment, on the inner surface 62a of the lower wall of the surge tank 62, the portions (intermediate portions) 62e to 62g between the four runner introduction ports 63b, 64b, 65b, 66b Since the three ribs 62b to 62d are provided so as to extend from each of them, the movement of the condensed water LQ in the predetermined direction (the direction in which the runner introduction ports 63b, 64b, 65b, and 66b are arranged) is restricted by the ribs. be. As a result, in the engine 1 including the intake device 3, the condensed water LQ accumulated on the inner surface 62a of the lower wall of the surge tank 62 can be prevented from deviating toward the downstream side in the air flow direction. In the cylinder 2a to which the runners 63, 64 are connected, a large amount of condensed water LQ is suppressed from being introduced at once into the runners 63, 64 having the runner introduction ports 63b, 64b on the downstream side of the air flow direction. misfire can be suppressed.

In addition, in the intake device 3 of the engine 1 according to the present embodiment, the intake manifold 6 is formed by joining the three members 6A to 6C including the base member 6A and the center member 6B. It is possible to easily manufacture an intake manifold 6 with a complicated internal structure having a deflector base 62i at 62h.

Further, in the intake device 3 of the engine 1 according to the present embodiment, each of the runner introduction ports 63b, 64b, 65b, and 66b is provided so as to be positioned above the inner surface 62a of the lower wall of the surge tank 62. For example, it is possible to prevent the condensed water LQ from undesirably flowing from the surge tank 62 into the runners 63 to 66 when the engine 1 is stopped. As a result, it is possible to prevent misfiring in the cylinder 2a when the engine 1 is restarted.

Further, in the intake device 3 of the engine 1 according to the present embodiment, each of the runners 63 to 66 has a portion extending upward from the runner introduction ports 63b, 64b, 65b, and 66b, so even if the engine 1 is stopped, The condensed water LQ remaining in the runners 63-66 is returned to the surge tank 62. Therefore, it is more suitable for suppressing misfiring in the cylinder 2a when the engine 1 is restarted.

Further, in the intake device 3 of the engine 1 according to the present embodiment, the EGR passage 81 is connected to the intake manifold 6, so that an excessive rise in combustion gas temperature is suppressed and the generation of nitrogen oxides (NOx) is suppressed. In addition, it is possible to reduce the pumping loss during intake. On the other hand, the water contained in the EGR gas condenses and the condensed water LQ generated from the EGR gas accumulates on the lower wall inner surface 62a of the surge tank 62. is provided, it is possible to prevent a large amount of condensed water LQ from being scooped up by the air flow and introduced into the runner introduction ports 63b, 64b, 65b, 66b at once. Therefore, in the engine 1 having the intake device 3, by connecting the EGR passage 81 to the intake manifold 6, while obtaining the above effect, misfire in the cylinder 2a due to the condensed water LQ being sent is suppressed. be able to.

As described above, the intake device 3 of the engine 1 according to the present embodiment prevents the condensed water LQ accumulated on the inner surface 62a of the lower wall of the surge tank 62 from flowing into the cylinder 2a at once. Therefore, it is possible to suppress the misfire in the cylinder 2a.

[Second embodiment]
An intake system for an engine according to the second embodiment will be described with reference to FIGS. 11 to 15. FIG. The intake system for an engine according to the present embodiment differs from that of the first embodiment in the structure of a part of the intake manifold 106, and the other parts are the same as those of the first embodiment. The difference from the first embodiment in the manifold 106 will be mainly described.

As shown in FIG. 11, also in the engine intake system according to the present embodiment, the intake manifold 106 is formed by joining three members including a base member (first member) 106A and a center member (second member) 106B. ing. The structures of the center member 106B and the cover member are the same as those of the center member 6B and the cover member 6C of the first embodiment. Also in this embodiment, the number of members constituting the intake manifold 106, the shape of each member, the constituent materials, and the like can be changed as appropriate.

The intake manifold 106 also has an intake introduction passage 161 having an introduction port 161a at one end, and a surge tank 162 to which four runners are connected. The intake air introduction passage 161 is arranged above the surge tank 162, and is partly separated from the space of the surge tank 162 by a partition wall 161b. The intake air introduction passage 161 is connected to a surge tank 162 at the right side of the paper surface of FIG. In this embodiment, the left-to-right direction of FIG. 11 also corresponds to the "predetermined direction".

A deflection table is formed on the side wall inner surface 162h of the surge tank 162 so that the protrusion height from the side wall inner surface 162h toward the space side (the front side of the paper surface of FIG. 11) gradually increases from the top to the bottom. A portion 162i is provided. The shape and formation range of the deflection table portion 162i are basically the same as those of the deflection table portion 62i of the first embodiment.

The inner surface 162a of the lower wall of the surge tank 162 is provided with three ribs 162b-162d. Each of the three ribs 162b to 162d extends from the portion between the runner inlets (illustration is omitted in FIG. 11) in the vertical direction and the predetermined 11 (the depth direction of the paper surface of FIG. 11). Also in this embodiment, the runner introduction port is provided so as to be positioned above the inner surface 162a of the lower wall of the surge tank 162, and the deflection base portion 162i of the inner surface 162h of the side wall is provided with the ribs 162b to 162d. is provided above the top of the

In the intake manifold 106 of this embodiment, a deflecting convex portion 162j is provided on a deflecting base portion 162i. The deflecting convex portion 162j is provided in a range from the vicinity of the portion where the rib 162d is provided to the vicinity of the portion where the rib 162b is provided in the predetermined direction. As shown in FIG. 12, in the state where the center member 106B is joined to the base member 106A, the deflecting convex portion 162j extends from the portion between the runner introduction port 163b and the runner introduction port 164b to the runner introduction port 166b. is formed in the range of As shown in FIGS. 11 and 12, the deflecting convex portion 162j has a triangular pyramidal shape, and the ridgeline portion 162k protruding most toward the center member 106B is arranged in a portion facing the portion where the runner introduction port 164b is provided. It is

The deflecting convex portion 162j is formed so that the slope on the side of the runner introduction ports 165b and 166b relative to the ridgeline portion 162k is gentler than the slope on the side of the runner introduction port 163b in the predetermined direction. ing. Further, as shown in FIGS. 13 and 14, the radius of curvature of the main surface of the deflection projection 162j increases from the side where the runner introduction port 166b is provided to the ridge line 162k in the predetermined direction. It is formed with a smooth curved surface (a surface without steps) that gradually increases in size.

As shown in FIG. 15, when the engine body is driven, fresh air and EGR gas (hereinafter referred to as "fresh air, etc.") are introduced into the surge tank 162 through the intake passage 161. (Arrow F1). In this case, since the partition wall 161b is provided to partially partition the space between the intake air introduction passage 161 and the space of the surge tank 162, fresh air and EGR gas are sent to the surge tank 162 while being mixed.

In the space inside the surge tank 162, fresh air or the like sent to the side where the #4 runner inlet 166b is provided (see also FIG. 12) hits the end wall inner surface 162l on the right side of the paper surface of FIG. (arrow F2). Fresh air or the like flowing downward along the inner surface 162l of the end wall and the inner surface 162h of the side wall of the surge tank 162 passes above the inner surface 162a of the lower wall by the deflection base portion 162i, and flows through the runner inlets 163b, 164b, 165b, 166b (arrow F4).

Moreover, fresh air or the like that has flowed downward along the end wall inner surface 162l also flows over the deflecting base portion 162i toward the end wall inner surface 162m on the left side of the paper surface of FIG. 15 (arrow F3). Fresh air or the like flowing as indicated by an arrow F3 flows along the deflecting convex portion 162j provided on the deflecting table portion 162i, and is directed toward the side where the runner introduction ports 163b and 164b are provided (see FIG. 12 together). ) and is introduced into runner inlets 163b, 164b, and so on.

The intake system for an engine according to the present embodiment has the same configuration as the first embodiment except for a part of the configuration of the surge tank 162 of the intake manifold 106, so that the same effects as the first embodiment can be obtained. .

Further, in the intake system of the engine according to the present embodiment, since the deflecting convex portion 162j is further provided on the deflecting base portion 162i, in the space inside the surge tank 162, fresh air or the like flowing along the side wall inner surface 162h is removed. It can be reliably guided to each of the runner introduction ports 163b, 164b, 165b, 166b by passing above the inner surface 162a of the lower wall. As a result, the pressure loss can be further reduced in the intake device for the engine according to the present embodiment.

[Third embodiment]
In the above-described first embodiment, the engine 1 including the four-cylinder engine main body 2 was used as an example, but in this embodiment, an engine main body including a six-cylinder engine main body is adopted. Since the configuration of the intake manifold 206 provided in the intake system differs according to the difference in the number of cylinders in the engine body, it will be described below. Except for the number of cylinders in the engine body and the configuration of the intake manifold 206, the intake system of the engine according to the present embodiment has the same configuration as the intake system 3 of the engine 1 according to the first embodiment.

1. External Configuration of Intake Manifold 206 The external configuration of intake manifold 206 will be described with reference to FIGS. 16 and 17. FIG.

As shown in FIG. 17, the intake manifold 206 according to this embodiment is also configured by joining a base member (first member) 206A, a center member (second member) 206B, and a cover member 206C. ing. Also in this embodiment, the base member 206A, the center member 206B, and the cover member 206C are each made of a resin material. Also in the present embodiment, like the first embodiment, the number of members constituting the intake manifold 206, the shape of each member, the constituent materials, and the like can be changed as appropriate.

As shown in FIGS. 16 and 17, the intake air introduction passage 261 is composed of a cylindrical pipe and has an opening (introduction port) 261a to which a throttle valve is connected at one end. The intake air introduction passage 261 is bent downward in an arc from the end where the introduction port 261a is opened. Then, as shown in FIG. 17, the intake introduction passage 261 is connected to a surge tank 262 .

As shown in FIG. 17, the surge tank 262 is arranged below the intake air introduction passage 261 also in this embodiment. 16 and 17, six liners (independent intake passages () 263-268) each extend upward from a portion of the surge tank 262 that communicates with the space. 16, the intake air introduction passage 261 is arranged to extend vertically between the runners 265 and 266 in the direction in which the runners 263 to 268 are arranged. 16 and 17 do not show runner outlets of the runners 263 to 268, but on the right side of the paper surface in FIG. It is provided so as to open toward it.

2. Internal Configuration of Surge Tank 262 The internal configuration of surge tank 262 in intake manifold 206 will be described with reference to FIG.

As shown in FIG. 18, the intake manifold 206 is constructed by joining a cover member 206C and a base member 206A with a center member 206B sandwiched therebetween, as indicated by arrows G1 and G2. The cover member 206C is provided with outer walls of the runners 263 to 268 and an introduction port 261a of the intake air introduction passage 261. As shown in FIG.

The center member 206B includes a part of the peripheral wall of the intake air introduction passage 261, a connection port 261b of the air intake introduction passage 261 with the surge tank 262, and runner introduction ports of the runners 263 to 268 (each of the runners 263 to 268). 263b, 264b, 265b, 266b, 267b, and 268b are provided, which communicate with the space of the surge tank 262 at . A connection port 261 b of the intake air introduction passage 261 is formed so as to face a lower wall inner surface 262 a of the surge tank 262 . In other words, the intake air introduction passage 261 is formed such that the center line passing through the center of the connection port 261 b intersects the inner surface 262 a of the lower wall of the surge tank 262 .

The base member 206A includes a portion of the outer wall including the lower wall of the surge tank 262, and runner outlets (ports connected to the intake ports of the engine body) 263a, 264a, 265a, and 266a of the runners 263 to 268, respectively. , 267a, 268a are provided. As shown in the enlarged portion of FIG. 18, in the intake manifold 206, two ribs 262b and 262c are provided on the inner surface 262a of the lower wall of the surge tank 262, and a deflection base portion 262d is provided on the inner surface 262h of the side wall of the surge tank 262. It is

The rib 262b of the two ribs 262b and 262c extends vertically from the portion between the runner inlets 264b and 265b and in the arrangement direction of the runner inlets 263b, 264b, 265b, 266b, 267b, and 268b. (predetermined direction). Similarly, the rib 262c is formed to extend in a direction intersecting both the vertical direction and the predetermined direction from a portion between the runner introduction port 266b and the runner introduction port 267b.

The deflection base portion 262d is formed on the lower wall inner surface 262a in the region between the portion provided with the rib 262b and the portion provided with the rib 262c in the predetermined direction (region including the central portion in the predetermined direction). It is formed so as to cover a part of the upper part. The deflection base portion 262d is provided so as to protrude from the lower portion of the side wall inner surface 262h of the surge tank 262 toward the center member 206B provided with the runner introduction ports 263b, 264b, 265b, 266b, 267b, and 268b. The height position of the projecting edge of the deflecting base portion 262d is higher than the tops of the ribs 262b and 262c provided on the inner surface 262a of the lower wall. The deflection base portion 262d is formed in a state where there is a space in the vertical direction between the lower wall inner surface 262a of the surge tank 262 and the region between the ribs 262b and 262c.

3. Suppression of Air Flow in Surge Tank 262 and Introduction of a Large Amount of Condensed Water to Runners 263 to 268 As shown in the enlarged portion of FIG. The fresh air and the like collide with the upper surface of the deflecting base portion 262d formed on the inner surface 262h of the side wall of the surge tank 262. As shown in FIG. Some of the fresh air, etc., which has collided with the upper surface of the deflection table portion 262d is sent from the runner inlets 265b, 266b toward the runners 265, 266 (arrow G3), and the other part is sent from the runner inlets 267b, 268b to the runners. 267, 268 (arrow G4), and the remaining portion is sent from runner introduction ports 263b, 264b toward runners 263, 264 (arrow G5).

Here, in the intake manifold 206, by providing the deflection base portion 262 on the inner surface 262h of the side wall of the surge tank 262, the fresh air introduced into the surge tank 261 through the intake introduction passage 261 is condensed in the region 262e. direct contact with is suppressed. Therefore, the condensed water accumulated in the region 262e becomes difficult to be scooped up by the flow of fresh air or the like, and a large amount of condensed water is sent to the runners 265, 266 from the runner introduction ports 265b, 266b, and these runners 265, 266 are connected. It is possible to suppress misfires in the cylinders that are

In addition, in this embodiment, since two ribs 262b and 262c are provided on the inner surface 262a of the lower wall of the surge tank 262 of the intake manifold 206, the flow of fresh air or the like affects the gap between the ribs 262b and 262c. The movement of condensed water from the region 262e to the regions 262f and 262g on both sides in the predetermined direction is restricted from the portions where the ribs 262b and 262c are provided. Therefore, in this embodiment as well, unevenness of the condensed water in the surge tank 262 of the intake manifold 206 is suppressed, and a large amount of condensed water is suppressed from being sent to a specific cylinder at once. Therefore, misfires in specific cylinders can be suppressed in the same manner as in the first embodiment.

The intake system for an engine according to this embodiment differs from that of the first embodiment in part in the construction of an intake manifold 206, but the rest of the construction is the same as that of the first embodiment. Effects similar to those of the first embodiment can be obtained.

[Modification]
In the first embodiment and the second embodiment, the intake manifolds 6, 106 are provided with the partition walls 61b, 161b that partially partition the spaces between the intake introduction passages 61, 161 and the surge tanks 62, 162. However, in the present invention, it is not always necessary to provide a partition.

In the first embodiment and the second embodiment, three ribs 62b to 62d and 162b to 162d are provided on the inner surfaces 62a and 162a of the lower walls of the surge tanks 62 and 162 of the intake manifolds 6 and 106, respectively. However, in the present invention, the same effect as described above can be obtained by providing at least one rib. In the present invention, the inner surface of the lower wall of the surge tank does not necessarily have to be provided with ribs.

In the third embodiment, two ribs 262b and 262c are provided on the inner surface 262a of the lower wall of the surge tank 262 in the intake manifold 206, but three or more ribs may be provided in the present invention. However, ribs may not be provided.

In the first embodiment and the second embodiment, in the surge tanks 62, 162 of the intake manifolds 6, 106, the deflection bases 62i, 162i are provided on the side wall inner surfaces 62h, 162h over the entire area in the predetermined direction. However, in the present invention, the deflection table may be provided in at least a partial area in the predetermined direction.

In addition, in the third embodiment, in the surge tank 262 of the intake manifold 206, the deflection base portion 262 is provided in a partial region of the side wall inner surface 262h in the predetermined direction. The deflection table may be provided so as to cover the entire area of .

Further, in the second embodiment, the deflection convex portion 162j is provided on the deflection table portion 162i, but a similar deflection convex portion may be provided on the deflection table portion 262d of the third embodiment.

In the first embodiment, the second embodiment, and the third embodiment, the runner introduction ports 63b, 64b, 65b, 66b, 163b, 164b, 165b, 166b, 263b, 264b, 266b, 267b and 268b are arranged at positions higher than the inner surfaces 62a, 162a and 262a of the lower walls of the surge tanks 62, 162 and 262. It may be arranged at the same height level as the inner surface or at a position lower than the inner surface of the lower wall of the surge tank.

In addition, in the first embodiment, the second embodiment, and the third embodiment, EGR gas is recirculated to the intake manifold 6, 106, 206 together with fresh air. EGR gas recirculation is not essential.

In addition, in the first embodiment, the second embodiment, and the third embodiment, the three members 6A, 6B, 6C, 106A, 106B, 106C, 206A, 206B, 206C are combined to form the intake manifolds 6, 106. , 206, but in the present invention, the intake manifold may be configured by combining two members or by combining four or more members.

Further, in the first embodiment, the second embodiment, and the third embodiment, the engine provided with the turbocharger is taken as an example, but the turbocharger is not an essential configuration in the present invention.

Further, in the first embodiment and the second embodiment, a 4-cylinder engine is used as an example of the engine body 2, and in the third embodiment, a 6-cylinder engine is used as an example of the engine body. In , it is possible to employ an engine with three or less cylinders, five cylinders, or an engine with seven or more cylinders.

1 engine 3 intake system 6, 106, 206 intake manifold 6A, 106A, 206A base member (first member)
6B, 106B, 206B Center member (second member)
6C, 106C Cover member 61, 161, 261 Intake introduction passage 61b, 161b Partition wall 62, 162, 262 Surge tank 62a, 162a, 262a Lower wall inner surface 62b, 62c, 62d, 162b, 162c, 162d, 262b, 262c Rib 62h, 162h, 262h side wall inner surface (opposing side wall inner surface)
62i, 162i, 262d Deflection table 63-66, 263-268 Runner (independent intake passage)
162j deflection protrusion

Claims (11)

An intake device for an engine,
an engine body having a plurality of cylinders and a cylinder head formed with an intake port connected to each of the plurality of cylinders;
an intake manifold through which air passes to the plurality of intake ports in the engine body;
with
The intake manifold is
a plurality of independent intake passages arranged along the cylinder row direction in the engine body and connected to each of the plurality of intake ports;
a surge tank having a space where the plurality of independent intake passages are assembled, and having openings in each of the plurality of independent intake passages aligned along a predetermined direction;
an intake introduction passage for introducing air into the surge tank;
has
The surge tank has a deflection table portion provided on the inner surface of the side wall facing the side wall having the plurality of openings across the space,
The deflection table section deflects the flow of air flowing along the inner surface of the side wall so that it passes above the inner surface of the lower wall of the surge tank and flows toward at least a part of the plurality of openings.
engine intake system. In the engine intake device according to claim 1,
The intake air introduction passage is formed to extend from one end side of the surge tank toward the other end side along the predetermined direction, and communicates with the space of the surge tank at the other end side. cage,
The intake air introduction passage and the space of the surge tank are partitioned by a partition except for the communicating portion on the other end side,
engine intake system. In the engine intake device according to claim 2,
The deflection table portion is provided so as to protrude from the inner surface of the opposing side wall toward the plurality of openings in a range facing the plurality of openings in the predetermined direction, and is configured to extend downward from above. provided so that the projection height toward the space side gradually increases as it goes,
engine intake system. In the engine intake device according to claim 2 or 3,
The surge tank further includes a deflecting convex portion provided on the deflecting table portion for deflecting the flow of air flowing through the space of the surge tank from the other end side to the one end side toward the plurality of openings. ,
engine intake system. In the engine intake device according to any one of claims 1 to 4,
The surge tank further comprises a plurality of ribs provided on the inner surface of the lower wall of the surge tank so as to extend from each portion between the adjacent openings toward the inner surface of the opposing side wall.
engine intake system. In the engine intake device according to claim 1,
The intake air introduction passage communicates with the space of the surge tank so as to point toward the inner surface of the lower wall at a portion communicating with the space of the surge tank in the central portion in the predetermined direction,
The deflection table protrudes from the inner surface of the opposing side wall toward a portion of the plurality of openings so as to cover a portion of the upper inner surface of the lower wall in a region including the central portion in the predetermined direction. is provided as
engine intake system. In the engine intake device according to claim 6,
The surge tanks are provided on the inner surface of the lower wall of the surge tanks at portions on both sides of the deflection table portion in the predetermined direction, and the surge tanks are arranged so as to face each other from portions between the adjacent openings. Further having two ribs extending toward the inner surface of the side wall,
engine intake system. In the engine intake device according to any one of claims 1 to 7,
In the intake manifold, the inner surface of the side wall provided with the plurality of openings and the inner surface of the side wall provided with the deflection table are joined together in opposing directions to form the space of the surge tank. Constructed by joining a plurality of members including a first member and a second member to
engine intake system. In the engine intake device according to any one of claims 1 to 8,
The plurality of openings are provided such that lower end portions thereof are located above the inner surface of the lower wall of the surge tank.
engine intake system. In the engine intake device according to any one of claims 1 to 9,
each of the plurality of independent intake passages has a portion extending upward from the opening;
engine intake system. In the engine intake device according to any one of claims 1 to 10,
An EGR passage for introducing EGR gas is connected to the intake manifold,
engine intake system.