JP5760893B2 - Intake system exhaust introduction structure - Google Patents

Description

  The present invention relates to an intake system exhaust introduction structure provided with a chamber into which exhaust of an internal combustion engine having a plurality of cylinders is introduced, and an exhaust distribution passage that is provided for each cylinder and distributes the exhaust in the chamber to the intake passage of each cylinder. About.

In an exhaust gas recirculation (EGR) device of an internal combustion engine, exhaust gas is introduced into intake air by supplying the exhaust gas to a surge tank or an intake branch pipe (intake path) (see, for example, Patent Documents 1 and 2).
In Patent Document 1, an EGR chamber is provided in the intake manifold, and exhaust is distributed from the exhaust distribution path of the EGR chamber to each intake path. The exhaust distribution path is connected with an angle between the curved wall surface on both sides of the bottom surface of the exhaust distribution path so that the discharge of water (condensed water) generated by condensation of water vapor in the exhaust is promoted. It is configured.

In Patent Document 2, the exhaust gas is distributed by passing the EGR exhaust passage into the space between the intake passages. Condensed water is not particularly considered.
In Non-Patent Document 1, dimple-like unevenness and protrusion unevenness for preventing the movement of condensed water are formed on the floor surface of the EGR delivery pipe. This prevents deterioration of drivability due to concentration of condensed water in a specific cylinder and biasing misfire.

JP 2009-209855 A (pages 10-13, FIGS. 4-6) JP 2009-133264 A (6th to 9th pages, FIGS. 1 to 3)

Japan Society for Invention and Innovation Technical Report 2011-501517 (first page, FIG. 2)

  Even if dimple-like irregularities are formed on the floor as in Non-Patent Document 1, since the holding force for stopping condensed water at that position is weak, sudden acceleration / deceleration, sudden turning, etc. in a vehicle equipped with an internal combustion engine are caused. When it occurs, the condensed water moves on the floor surface by moving between and over the dimple-like irregularities. This may cause the condensed water to concentrate on a specific cylinder.

  When protrusions are formed on the floor surface, the movement of condensed water can be suppressed to some extent as compared with dimple-like irregularities. However, the holding power that stops the condensed water in the direction along the ridge is weak. For this reason, the effect which prevents that condensed water moves to other inner surfaces, such as a side wall surface and a ceiling surface, along a protrusion by vehicle acceleration / deceleration is small. If the condensed water moves to an inner surface that does not form a protrusion such as a ceiling surface, the condensed water may be biased to a specific cylinder by moving on the inner surface due to subsequent vehicle turning or the like.

  An object of the present invention is to prevent the condensed water from being biased toward a specific cylinder by increasing the holding power of the condensed water on the inner surface of the chamber.

In the following, means for achieving the above-mentioned purpose, and its operation and effect are described.
The intake system exhaust introduction structure according to claim 1, wherein a chamber into which exhaust of an internal combustion engine having a plurality of cylinders is introduced, and an exhaust distribution path that is provided for each cylinder and distributes exhaust in the chamber to an intake path of each cylinder. a suction system exhaust introduction structure with bets on the inner surface of said chamber, said protrusion extending in orthogonal direction is provided to the array direction of the opening of the exhaust distribution path, the projection is the same at least a portion in the extending direction of the protrusion, the inner surface of the chamber are secondary ridges are formed extending in the protrusions in the same direction to protrude from and both sides of the ridge has a gap, the butt The portion where the sub-projection is formed in the strip is a circular sub-projection having a cross-sectional shape perpendicular to the extending direction of the projection at the same portion, and a diameter larger than the width of the projection at the tip of the projection. it is characterized by a shape but is formed .

The protrusion on the inner surface of the chamber extends in a direction orthogonal to the arrangement direction of the openings of the exhaust distribution passage, thereby exhibiting a certain amount of condensate movement prevention effect. A sub-projection having a gap with the inner surface of the chamber is formed.

Thus, the side surface of the ridge is not a mere smooth surface but a sub ridge is formed. In addition, the auxiliary protrusion has a gap with the inner surface of the chamber. The gap is a hollow space surrounded by at least three sides by the inner surface, the ridges, and the sub ridges .

  Condensed water is generated in the gap, condensed water flows along the ridges, or condensed water flows over the ridges. Once flowing into this gap, a relatively strong force is exerted to keep the condensed water adhering to the gap due to surface tension between the three surfaces and capillary action in the gap.

  Therefore, even if sudden acceleration / deceleration or sudden turning occurs in a vehicle or the like on which an internal combustion engine is mounted, the condensed water held strongly as described above does not get over the ridges on the inner surface of the chamber. It becomes difficult to move also in the direction along.

As described above, the retention of condensed water on the inner surface of the chamber can be increased. Therefore, it is possible to prevent the condensed water from being biased toward the specific cylinder .

In addition, by forming sub-ridges on both sides of the ridge, not only on one side of the ridge, but also on both sides of the ridge, a hollow shape surrounded by three sides corresponding to the length of the sub-ridge. There is a gap.
As a result, a large amount of condensed water can be reliably held, and even if a large amount of condensed water is generated, it is possible to prevent the condensed water from being biased toward a specific cylinder.

And it can implement | achieve by forming in the cross-sectional circle | round | yen as above-mentioned as a secondary protrusion which exists in the both sides | surfaces of a protrusion. Since such a configuration has a simple shape, the productivity is increased.

The intake system exhaust introduction structure according to claim 2, wherein , in the intake system exhaust introduction structure according to claim 1 , a cross-sectional shape of the chamber perpendicular to the arrangement direction of the openings of the exhaust distribution path and including the protrusions Then, the site | part in which the said protrusion is not provided exists in a part of inner surface of the chamber, It is characterized by the above-mentioned.

In the intake system exhaust introduction structure according to claim 3 , in the intake system exhaust introduction structure according to claim 2 , the auxiliary protrusion is formed only at one end in the extending direction of the protrusion. Features.

The intake system exhaust introducing structure according to claim 4, in the intake system exhaust introducing structure according to any one of claims 1 to 3, the internal combustion engine is an internal combustion engine mounted on a vehicle, the exhaust distribution channels The opening is arranged in the left-right direction of the vehicle.

  In the intake system exhaust introduction structure provided in such an internal combustion engine, condensed water may concentrate on the side wall surface of the chamber due to rapid acceleration / deceleration of the vehicle. However, the condensed water is strongly held by the protrusions as described above. Therefore, it is difficult to move the condensed water. For this reason, even if the vehicle turns sharply, it is possible to prevent the condensed water from being biased toward a specific cylinder.

  Therefore, misfire does not occur remarkably only in a specific cylinder, and low frequency vibration can be prevented from occurring in the internal combustion engine. Therefore, the resonance of the vehicle can be prevented and the vehicle driver does not feel uncomfortable.

FIG. 2 is a front view showing a main configuration of an intake manifold in the internal combustion engine of the first embodiment. Similarly rear view. Similarly left side view. Similarly perspective view. XX sectional drawing in FIG. FIG. 4 is a perspective view showing the inside of a third piece according to the first embodiment. The partial expansion perspective view of the said 3rd piece. (A)-(C) Explanatory drawing of the protrusion shape and condensed water holding | maintenance state of the said 3rd piece. The graph which compared the influence which the amount of condensed water has on the vehicle drivability with the intake manifold of Embodiment 1, and the intake manifold of a comparative example. (A)-(C) Sectional drawing which shows the protrusion shape example of the 3rd piece of Embodiment 2. FIG. (A)-(C) Sectional drawing which shows the protrusion shape example of the 3rd piece of Embodiment 2. FIG. (A)-(C) Sectional drawing which shows the protrusion shape example of the 3rd piece of Embodiment 2. FIG. FIG. 6 is a perspective view showing the inside of a third piece of Embodiment 3.

[Embodiment 1]
<Configuration of Embodiment 1> FIGS. 1 to 4 show a configuration of a main part of an intake manifold 2 to which the above-described intake system exhaust introduction structure is applied. The internal combustion engine provided with the intake manifold 2 has a plurality of cylinders and is mounted horizontally on the vehicle for vehicle travel.

  The intake manifold 2 includes a surge tank 4 through which intake air is introduced from the throttle valve. An intake branch pipe collecting portion 6 is provided on the downstream side of the surge tank 4. The surge tank 4 and the intake branch pipe assembly 6 are formed of resin. Incidentally, a through-hole for installing an intake air temperature sensor and the like, various engaging portions for supporting the intake manifold 2 itself, and the like can be provided on the outer peripheral surface.

  The internal combustion engine is a four-cylinder internal combustion engine, and the intake branch pipe assembly 6 includes four intake branch pipes 6a, 6b, 6c, and 6d as intake paths of the respective cylinders. The internal combustion engine may have another number of cylinders. In this case, the intake manifold 2 is provided with intake branch pipes corresponding to the number of cylinders. In the case of a multi-bank internal combustion engine such as a V-type engine, an intake manifold 2 is provided for each bank, and each intake manifold 2 is provided with intake branch pipes corresponding to the number of cylinders in the same bank. Become.

  The intake manifold 2 is formed by joining several resin pieces by vibration welding or the like. Here, as shown in the longitudinal cross-sectional configuration of FIG. 5, three pieces 2a, 2b, 2c are integrated by vibration welding. By integrating the three pieces 2a, 2b and 2c, an EGR chamber 8 is formed below the intake branch pipe assembly 6 along the arrangement direction of the intake branch pipes 6a to 6d. In addition, as for the intake manifold 2, the 1st piece 2a is arrange | positioned at the vehicle front side, and the 2nd piece 2b is arrange | positioned at the vehicle rear side. Accordingly, in the EGR chamber 8, the third piece 2c is located on the vehicle front side.

  In the EGR chamber 8, when exhaust gas recirculation is executed, exhaust gas is introduced from an exhaust gas supply unit 8 a formed on one side of the intake branch pipe assembly 6 through an EGR valve provided in the EGR device. The exhaust gas is distributed to the intake branch pipes 6a to 6d via the exhaust distribution passages 10, 12, 14, and 16 that open to the EGR chamber 8.

  Among the inner surface of the EGR chamber 8, a plurality of protrusions 20, 22, 24, 26, 28, 30, 32 are provided on the side wall surface 8b formed by the third piece 2c as shown in FIG. Yes. Each protrusion 20-32 is formed in the state extended in the orthogonal direction with respect to the arrangement direction of the opening part of the exhaust distribution paths 10-16, and is arrange | positioned in parallel and providing the space | interval.

  These ridges 20 to 32 are divided into three groups. The first group of protrusions 20, 22, and 24 are formed at positions corresponding to between the exhaust distribution path 10 of the # 1 cylinder and the exhaust distribution path 12 of the # 2 cylinder. The second group of protrusions 26 is formed at a position corresponding to between the exhaust distribution path 12 of the # 2 cylinder and the exhaust distribution path 14 of the # 3 cylinder. The third group of protrusions 28, 30, and 32 are formed at positions corresponding to between the exhaust distribution path 14 of the # 3 cylinder and the exhaust distribution path 16 of the # 4 cylinder.

These ridges 20 to 32 are respectively connected to a plurality of floor surface ridges 34 formed on the floor surface 8 c of the inner surface of the EGR chamber 8 on the lower end side.
Of the inner surface of the EGR chamber 8, there is no protrusion on the ceiling surface 8d and it is a smooth surface. Therefore, on the inner surface of the EGR chamber 8, a series of ridges composed of the ridges 20 to 32 on the side wall surface 8 b and the floor surface ridges 34 on the floor surface 8 c are formed with respect to the arrangement direction of the openings of the exhaust distribution paths 10 to 16. And extending in the orthogonal direction.

  The third piece 2c is designed to have a narrow central space. For this reason, the second group of protrusions 26 arranged at the center of the third piece 2c are formed only on the side adjacent to the floor surface 8c, and the length thereof is shortened compared to the other groups. Yes. This prevents the fluidity of the exhaust flow in the EGR chamber 8 from being lowered.

  The first group of protrusions 20 to 24 and the third group of protrusions 28 to 32 are formed on the entire circumference of the inner surface of the third piece 2c. Among the two groups of ridges 20 to 24 and 28 to 32, the ridge 22 at the center of the first group and the ridge 30 at the center of the third group which are formed at positions where the space is particularly widened. As shown in FIG. 7, the cylindrical body 36 is formed only at the end on the ceiling surface 8d side. The cylindrical body 36 has an axial direction in the same direction as the protrusions 22 and 30 at the ends of the protrusions 22 and 30.

  As shown in FIG. 8A, the diameter R <b> 2 of the cylindrical body 36 is larger than the width R <b> 1 of the protrusions 22 and 30. Therefore, the cylindrical body 36 has a portion protruding from the position of the side surface when the cylindrical body 36 indicated by the broken line is not formed. The projecting portions form convex portions 36a and 36b projecting from the side surfaces M1 and M2 on both sides of the ridges 22 and 30, respectively.

Since the convex portions 36a and 36b are formed in this way, there are three sides between the side wall surface 8b and the convex portions 36a and 36b: the side wall surface 8b, the protrusions 22 and 30, and the convex portions 36a and 36b. Two hollow-shaped gaps Sp1 and Sp2 surrounded are generated.
<Operation of Embodiment 1> As described above, each of the protrusions 22 and 30 has two hollow gaps Sp1 and Sp2 surrounded by three sides.

In a simple ridge that does not have the convex portions 36a and 36b indicated by broken lines in FIG. 8A, no gaps Sp1 and Sp2 surrounded on three sides are generated.
When condensed water is generated on the inner surface of the EGR chamber 8 and adheres as water droplets, the condensed water tends to move along the inner surface of the EGR chamber 8 as the vehicle suddenly accelerates or decelerates. For example, the condensed water adhering to the floor surface 8c and the ceiling surface 8d as water droplets due to the sudden deceleration of the vehicle once flows to the side wall surface 8b, that is, the third piece 2c side.

  However, since the side wall surface 8b of the third piece 2c is provided with the ridges 20 to 32 as shown in FIG. 6, water droplets flow between the ridges 20 to 32. Even if the vehicle turns in this state and lateral acceleration is applied, if the lateral acceleration is small to some extent, the flow of water droplets is blocked by the ridges 20 to 32 themselves. For this reason, the condensed water does not concentrate on the exhaust distribution path 10 of the # 1 cylinder or the exhaust distribution path 16 of the # 4 cylinder, for example.

  As shown in FIG. 8A, with respect to the ridges 22 and 30 arranged in the wide region of the side wall surface 8b, convex portions 36a and 36b are formed by the cylindrical body 36 at positions adjacent to the ceiling surface 8d. Has been. As a result, two recessed gaps Sp1, Sp2 surrounded by three sides are formed at the ends of the protrusions 22,30. For this reason, as shown in FIG. 8B, not only when a small amount of water droplets Wd flows in or is generated, but also when a large amount of water droplets Wd flows as shown in FIG. Due to tension or the like, the water droplet Wd adheres in the gaps Sp1 and Sp2 and is strongly held.

For this reason, even if a larger lateral acceleration is applied, the ridges 22 and 30 are not overcome, and the condensed water does not concentrate on the exhaust distribution passage 10 of the # 1 cylinder and the exhaust distribution passage 16 of the # 4 cylinder.
Further, as the vehicle changes from deceleration to acceleration, water droplets Wd flow from the third piece 2c side to the ceiling surface 8d side along the ridges 22 and 30, as described above. Since the condensed water existing in the hollow gaps Sp1 and Sp2 is strongly held, the movement to the ceiling surface 8d is prevented. Therefore, the condensed water is also prevented from flowing into the exhaust distribution passage 10 of the # 1 cylinder and the exhaust distribution passage 16 of the # 4 cylinder through the ceiling surface 8d.

  The result of measuring the amount of water injection (cc) and the drivability state (here, the low frequency vibration level of the vehicle) by executing water droplet spraying in the EGR chamber 8 with respect to the intake manifold 2 of the present embodiment. 9 is indicated by a solid line in the graph of FIG. As a comparative example, the result of measuring the drivability state by performing water droplet spraying similarly for the EGR chamber in which all the protrusions do not have convex portions on the side surfaces is shown by broken lines.

As shown in the drawing, the drivability is better in the example than in the comparative example over the entire amount of water injection (cc) by spraying.
<Effects of First Embodiment> (1) As described above, the protrusions 22 and 30 are provided with convex portions 36a and 36b on both side surfaces M1 and M2, respectively. The convex portions 36 a and 36 b are formed as sub-projections extending in the same direction as the projections 22 and 30.

  There are gaps Sp1 and Sp2 between the convex portions 36a and 36b and the inner surface (side wall surface 8b) of the EGR chamber 8. The gaps Sp1 and Sp2 exist as hollow spaces surrounded on three sides by the inner surface (side wall surface 8b) of the EGR chamber 8, the ridges 22 and 30, and the convex portions 36a and 36b.

  Condensed water is directly generated in the gaps Sp1 and Sp2, or condensed water flows along the protrusions 22 and 30 during rapid acceleration and deceleration. Once the condensed water flows into the gaps Sp1 and Sp2, the condensed water adheres to the gaps Sp1 and Sp2 and is strongly held by the surface tension between the three surfaces and the capillary action in the gaps Sp1 and Sp2. The

  Therefore, even if sudden acceleration / deceleration or sudden turning occurs in a vehicle or the like on which the internal combustion engine is mounted, the water droplets Wd of the condensed water that is strongly held as described above are not only over the protrusions 22 and 30 but also the protrusions. Movement along the strips 22 and 30 is also prevented.

  In this way, even if a large amount of condensed water is generated on the inner surface of the EGR chamber 8, the retention capacity of the condensed water is increased by the protrusions 22 and 30, so that the EGR device in the intake system of the multi-cylinder internal combustion engine It is possible to prevent the condensed water from being biased toward the specific cylinder.

  (2) The protrusions 36a and 36b, which are sub-projections, are formed so that the cylindrical body 36 having a diameter R2 larger than the width R1 of the projections 22 and 30 has the axial direction the same as that of the projections 22 and 30. It is the shape formed in the top part of the strips 22 and 30.

Such a configuration has a simple shape and is easy to mold with a resin or the like, so that productivity is increased.
(3) In particular, the protrusions 22 and 30 provided at wide positions in the third piece 2c form convex portions 36a and 36b at end positions on the ceiling surface 8d side. For this reason, a large amount of condensed water does not flow out of the wide portion of the third piece 2c with respect to the ceiling surface 8d on which no protrusion is formed. Therefore, it is possible to prevent the condensed water from concentrating on the specific cylinder through the ceiling surface 8d.

Also in the protrusions 22 and 30, the convex portions 36a and 36b are only the end portion on the ceiling surface 8d side, so that the condensed water can be reliably prevented from being biased to the specific cylinder with a simpler configuration.
(4) The internal combustion engine in which the intake manifold 2 of the present embodiment is used is an internal combustion engine mounted on a vehicle, and the arrangement direction of the openings of the exhaust distribution paths 10 to 16 is the left-right direction of the vehicle.

  In the intake system exhaust introduction structure provided in such an internal combustion engine, condensed water may concentrate on the side wall surface 8b of the EGR chamber 8 due to rapid acceleration / deceleration of the vehicle. However, as described above, the condensed water is strongly held by the protrusions 22 and 30 existing on the side wall surface 8b, and the movement thereof is prevented.

  From this, misfire does not occur remarkably only in a specific cylinder, and low frequency vibration can be prevented as shown in FIG. Therefore, the resonance of the vehicle can be prevented and the vehicle driver does not feel uncomfortable.

[Embodiment 2]
<Configuration of Embodiment 2> In this embodiment, the shape as shown in FIGS. 10 to 12 is adopted as the shape of the convex portions formed on the side surfaces M1 and M2 of the ridges.

  In the example of FIG. 10A, the ridge 104 formed on the inner surface 102 of the EGR chamber is formed with a square prismatic body 106 on the top thereof with the axial direction being the same as the ridge 104. Shape. The width Rb of the prismatic body 106 is larger than the width Ra of the protrusion 104. For this reason, the convex parts 106a and 106b protrude from both side surfaces M1 and M2 of the protrusion 104. As a result, there are two hollow gaps Sp1, Sp2 between the convex portions 106a, 106b and the inner surface 102 of the EGR chamber.

  In the example of FIG. 10B, the protrusion 114 formed on the inner surface 112 of the EGR chamber is formed with a square prismatic body 116 on the top thereof with the axial direction being the same as the protrusion 114. Shape. The width Rb of the prismatic body 116 is larger than the width Ra of the protrusion 114. However, unlike the configuration of FIG. 10A, the prismatic body 116 protrudes from only one side surface M <b> 2 of the ridge 114 to form one convex portion 116 a. There is no protrusion on the other side surface M1. As a result, one hollow gap Sp1 exists between the convex portion 116a and the inner surface 112 of the EGR chamber.

  In the example of FIG. 10C, the protrusion 124 formed on the inner surface 122 of the EGR chamber has a shape in which a cylindrical body 126 is formed on the top thereof with the axial direction being the same as the protrusion 124. . The diameter Rb of the cylindrical body 126 is larger than the width Ra of the ridge 124. However, unlike the configuration of the first embodiment, the cylindrical body 126 protrudes from only one side surface M2 of the protrusion 124 to form one convex portion 126a. There is no protrusion on the other side surface M1. As a result, one hollow gap Sp1 exists between the convex portion 126a and the inner surface 122 of the EGR chamber.

  In the example of FIG. 11A, the protrusion 134 formed on the inner surface 132 of the EGR chamber has square columnar convex portions 136a and 136b formed on both side surfaces M1 and M2 on the top side. Further, also in the middle between the convex portions 136a and 136b and the inner surface 132 of the EGR chamber, square columnar convex portions 137a and 137b are formed on both side surfaces M1 and M2. As a result, there are four hollow spaces Sp1, Sp2, Sp3, Sp4 between the convex portions 136a to 137b and the inner surface 132.

  In the example of FIG. 11B, the protrusion 144 formed on the inner surface 142 of the EGR chamber has a quadrangular columnar convex portion 146a on both side surfaces M1, M2 between the top and the inner surface 142 of the EGR chamber. , 146b. Accordingly, there are two hollow gaps Sp1 and Sp2 between the convex portions 146a and 146b and the inner surface 142. Corners C1 and C2 are also formed between the convex portions 146a and 146b and the tip end side of the protrusion 144.

  In the example of FIG. 11C, the protrusion 154 formed on the inner surface 152 of the EGR chamber has two columnar protrusions 156a and 156b formed at the top. Further, semi-cylindrical convex portions 157a and 157b are formed on both side surfaces M1 and M2 between the top portion and the inner surface 152 of the EGR chamber. As a result, there are four recessed gaps Sp1 to Sp4 between the convex portions 156a to 157b and the inner surface 152. Further, in this configuration, there is one corner C1 between the top convex portions 156a and 156b.

  In the example of FIG. 12A, the protrusion 164 formed on the inner surface 162 of the EGR chamber has plate-like convex portions 166a and 166b formed at the top. Further, convex portions 167a, 167b, 168a, 168b are formed on both side surfaces M1, M2 at two intermediate positions between the convex portions 166a, 166b and the inner surface 162 of the EGR chamber. As a result, there are six hollow spaces Sp1, Sp2, Sp3, Sp4, Sp5, Sp6 between the convex portions 166a to 168b and the inner surface 162.

  In the example of FIG. 12B, the protrusion 174 formed on the inner surface 172 of the EGR chamber forms plate-like convex portions 176a and 176b on the top. The tip portions 176c and 176d of the convex portions 176a and 176b are bent toward the inner surface 172 side. Thus, there are two hollow gaps Sp1 and Sp2 between the convex portions 176a and 176b and the inner surface 172. In addition, the bent portions Sp1 and Sp2 of the gaps Sp1 and Sp2 form a space sandwiched between the side surfaces M1 and M2 and the tips 176c and 176d by the bent tips 176c and 176d.

In the example of FIG. 12C, the cylindrical body 186 occupies most of the protrusions 184 formed on the inner surface 182 of the EGR chamber. Thus, the convex portions 186a and 186b are formed so as to cover the whole on both side surfaces M1 and M2. As a result, between the convex portions 186 a and 186 b and the inner surface 182, there are two hollow gaps Sp <b> 1 and Sp <b> 2 on both sides of the protrusion 184.
<Operation of Embodiment 2> As described above, the protrusions 104, 114, 124, 134, 144, 154, 164, 174, and 184 in FIGS. 10 to 12 are recessed gaps Sp1 to Sp6 surrounded by three sides. Exists. Therefore, as described in the first embodiment, a large amount of water droplets of condensed water adheres to the gaps Sp1 to Sp6 and is strongly held by capillary action or surface tension.

In the protrusions 134, 154, and 164 shown in FIGS. 11A, 11C, and 12A, the number of the gaps Sp1 to Sp6 is large, so that a larger amount of condensed water droplets can be strongly held.
As shown in FIG. 12B, the condensate retention strength can be particularly enhanced in the regions D1 and D2 formed by bending the tip portions 176c and 176d of the convex portions 176a and 176b toward the inner surface 172 side.

In FIGS. 11B and 11C, corners C1 and C2 are generated by the convex portions 146a and 146b and the convex portions 156a and 156b, in addition to the hollow gap. Such corners C1 and C2 also have the effect of enhancing the retention of condensed water by surface tension and capillary action.
<Effects of Second Embodiment> (1) The effects of the first embodiment are produced. In particular, the ridges 134, 154, 164 in which the number of the gaps Sp1 to Sp6 is increased and the ridge 174 in which the tips of the convex portions 176a, 176b are bent are more effective.

[Embodiment 3]
<Configuration of Embodiment 3> As shown in FIG. 13, the third piece 302 of this embodiment has all the protrusions 320, 322, 324, 326, 328, 330, 332 adjacent to the ceiling surface of the EGR chamber. A cylindrical body 336 is formed at the end position where the cylindrical body 336 is formed, as with some of the protrusions in the first embodiment. Further, all the protrusions 320 to 332 form the cylindrical body 338 at the end position adjacent to the floor surface of the EGR chamber.
<Operation of Embodiment 3> Since all the protrusions 320 to 332 form the cylindrical bodies 336 and 338 at both ends, a large number of recesses are formed due to the presence of a large number of convex portions. Therefore, the third piece 302 as a whole can strongly hold a larger amount of condensed water droplets.
<Effect of Embodiment 3> (1) The effect of Embodiment 1 is more strongly generated.

[Other embodiments]
-In the said Embodiment 3, the convex part similar to the said Embodiment 1 was formed by forming a cylindrical body in a protrusion. Instead of this cylindrical body, the convex portions shown in the second embodiment may be adopted at both end positions of all the protrusions 320 to 332 in the third embodiment.

  -In each above-mentioned embodiment, although the convex part was formed only in the edge part of a protrusion, you may form in a center part.

  2 ... Intake manifold, 2a ... 1st piece, 2b ... 2nd piece, 2c ... 3rd piece, 4 ... Surge tank, 6 ... Intake branch pipe assembly, 6a, 6b, 6c, 6d ... Intake branch pipe, 8 ... EGR chamber, 8a ... exhaust supply section, 8b ... side wall surface, 8c ... floor surface, 8d ... ceiling surface, 10, 12, 14, 16 ... exhaust distribution path, 20, 22, 24, 26, 28, 30, 32 ... Projection, 34 ... Floor projection, 36 ... Cylindrical body, 36a, 36b ... Projection, 102 ... Inner surface of EGR chamber, 104 ... Projection, 106 ... Rectangular column, 106a, 106b ... Projection, 112 ... EGR chamber , 114 ... projection, 116 ... prism, 116 a ... projection, 122 ... inner surface of EGR chamber, 124 ... projection, 126 ... cylindrical body, 126 a ... projection, 132 ... inner surface of EGR chamber, 134 ... projection Article 136a, 1 6b, 137a, 137b ... convex portion, 142 ... inner surface of EGR chamber, 144 ... protrusion, 146a, 146b ... convex portion, 152 ... inner surface of EGR chamber, 154 ... protrusion, 156a, 156b, 157a, 157b ... convex portion 162 ... EGR chamber inner surface, 164 ... protrusion, 166a, 166b, 167a, 167b, 168a, 168b ... convex portion, 172 ... EGR chamber inner surface, 174 ... protrusion, 176a, 176b ... convex portion, 176c, 176d ... tip part, 182 ... inner surface of EGR chamber, 184 ... protrusion, 186 ... cylindrical body, 186a, 186b ... convex part, 302 ... third piece, 320, 322, 324, 326, 328, 330, 332 ... protrusion , 336, 338 ... cylindrical body, C1, C2 ... corner, D1, D2 ... partial area, M1, M2 ... side face Sp1, Sp2, Sp3, Sp4, Sp5, Sp6 ... depression-like gap, Wd ... water droplets of condensed water.

Claims (4)

An intake system exhaust introduction structure comprising a chamber into which exhaust of an internal combustion engine having a plurality of cylinders is introduced, and an exhaust distribution path that is provided for each cylinder and distributes exhaust in the chamber to an intake path of each cylinder;
On the inner surface of the chamber, a ridge extending in a direction orthogonal to the arrangement direction of the openings of the exhaust distribution passage is provided,
The ridge has a sub ridge extending at least partially in the extending direction of the ridge, having a gap with the inner surface of the chamber and projecting from both sides of the ridge and extending in the same direction as the ridge. Formed ,
A portion of the ridge where the auxiliary ridge is formed is a circular auxiliary member having a cross-sectional shape perpendicular to the extending direction of the ridge at the same portion and a diameter larger than the width of the ridge at the tip of the ridge. An intake system exhaust introduction structure characterized by a shape in which a protrusion is formed . 2. The intake system exhaust introduction structure according to claim 1, wherein in the cross-sectional shape of the chamber orthogonal to the arrangement direction of the openings of the exhaust distribution passage and including the protrusions, the protrusions are formed on a part of the inner surface of the chamber. Intake system exhaust introduction structure characterized in that there is a portion where is not provided . 3. The intake system exhaust introduction structure according to claim 2 , wherein the auxiliary projection is formed only at one end in the extending direction of the projection . The intake system exhaust introduction structure according to any one of claims 1 to 3 , wherein the internal combustion engine is an internal combustion engine mounted on a vehicle, and an arrangement direction of the openings of the exhaust distribution path is a lateral direction of the vehicle. An intake system exhaust introduction structure characterized by being.

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