JP5505255B2 - Intake device for internal combustion engine - Google Patents

Description

  The present invention relates to an intake device for an internal combustion engine, and in particular, an internal combustion engine in which a gas distribution introduction pipe for distributing and introducing exhaust gas recirculation gas containing moisture and oil is introduced into an intake manifold that sucks air into each cylinder of a multi-cylinder internal combustion engine. The present invention relates to an intake device.

  2. Description of the Related Art In a multi-cylinder internal combustion engine (hereinafter also referred to as an engine) for a vehicle, as an intake device that sucks air into a plurality of intake ports, a relatively large-capacity surge tank that introduces outside air through an air cleaner and an inside of the surge tank One having an intake manifold in which a plurality of intake branch pipes arranged in parallel so that air is sucked into a plurality of intake ports from one chamber is integrally used. Then, in the surge tank of the intake manifold, for example, oil or water vapor such as blow-by gas or purge air from the canister is used for ventilation in the crankcase from which blow-by gas leaks or for evaporating fuel in the fuel supply system. The contained gas is often introduced. In addition, with the increasing demand for exhaust purification performance, engines equipped with an exhaust gas recirculation (EGR) device that is effective in reducing NOx (nitrogen oxides) are becoming increasingly popular. In many such engines, EGR gas is mixed with intake air in a surge tank. Further, in the case of lean combustion and an increase in the amount of EGR, or in an engine that requires high fuel efficiency and high output, an EGR cooler (exhaust cooler) is frequently used to lower the temperature of EGR gas.

  As a conventional intake device mounted on such an engine, for example, a gas introduction hole containing water vapor is formed at an appropriate position other than a raised portion protruding on the inner wall surface of a surge tank, while a surge is formed in the raised portion. An intake negative pressure extraction hole for taking out the intake negative pressure in the tank is formed, and a guide groove is formed in the raised portion so that moisture flowing down the wall inner surface above the raised portion is away from the intake negative pressure extraction hole. Those are known (for example, see Patent Document 1).

  Further, it is known that the vicinity of the end portion of the EGR passage forms a peripheral circuit along the inner peripheral wall of the EGR valve, and the EGR gas is cooled by intake air in a part of the EGR passage (for example, Patent Document 2).

  Furthermore, the intake passage is made into a venturi shape that restricts the flow path at a predetermined position on the downstream side of the throttle valve, and an opening for introducing the outlet side end of the exhaust gas recirculation passage is disposed at the predetermined position. There is a system in which gas and intake air flowing into the intake passage are sufficiently mixed to make the cylinder distribution of EGR gas uniform, and soot generation in a cylinder that causes excessive inflow of EGR gas is suppressed (for example, And Patent Document 3).

JP 2007-040142 A JP 2003-056413 A JP 2000-329010 A

  However, in the conventional intake device for an internal combustion engine as described above, since moisture-containing gas is introduced into the surge tank of the intake manifold, moisture or condensed water separated from EGR gas in the surge tank or If the icing matter accumulates easily and is sucked into the cylinder, it will lead to instability of combustion and misfire in the cylinder, resulting in deterioration of exhaust emission of the internal combustion engine or driver of the vehicle equipped with the internal combustion engine There was a problem that the performance deteriorated.

  On the other hand, if the EGR gas is mixed with the intake air downstream from the surge tank, the occurrence of problems such as the generation of condensed water in the surge tank and the suction of the ice pieces to the cylinder side can be prevented. Although it was possible, there were the following problems.

  In other words, in this case, an EGR gas distribution pipe for distributing and supplying EGR gas to a plurality of intake branch pipes arranged in parallel in the intake manifold is provided, and particularly in the EGR gas distribution passage inside the EGR gas distribution passage. Condensed water or the like (hereinafter simply referred to as “condensed water”) is liable to occur due to condensation of moisture-containing EGR gas on one end side away from the gas inlet. A vehicle running state in which acceleration in the axial direction of the EGR gas distribution passage acts during vehicle running, particularly a vehicle running state in which the acceleration acts greatly (for example, a horizontally mounted four-cylinder engine is mounted). When the vehicle is turning or turning), the condensed water in the EGR gas distribution passage is concentrated on the end portion side of the EGR gas distribution passage, and particularly in one end side cylinder away from the EGR gas introduction port. Condensed water tends to concentrate and flow into a specific cylinder-specific introduction hole for introducing EGR gas. For this reason, when the EGR gas distribution pipe misfires at one end side of the cylinder, the balance of torque generated by the multi-cylinder engine is lost and torque fluctuation is caused. When the torque fluctuation frequency matches the resonance frequency of the mission, the vehicle The vehicle drivability may deteriorate due to unpleasant vehicle vibrations generated by the passengers. Furthermore, when the material of the EGR gas distribution pipe is easily corroded by acidic condensate, it is set so that the inflow of the condensed water to each cylinder introduction hole is easy to prevent corrosion of the EGR gas distribution pipe. Therefore, the occurrence of vehicle vibration due to the torque fluctuation as described above is likely to occur.

  The present invention has been made in order to solve the above-described conventional problems. Even when condensed water is generated in the EGR gas distribution pipe, the condensed water is concentrated in a specific cylinder introduction hole of the EGR gas distribution pipe. Therefore, it is possible to provide an intake device for an internal combustion engine that can effectively prevent inflow and reliably prevent deterioration of vehicle drivability.

  In order to solve the above-described problems, an intake apparatus for an internal combustion engine according to the present invention includes: (1) a plurality of intake branch pipes provided corresponding to a plurality of intake ports of a multi-cylinder internal combustion engine and spaced apart from each other; And a surge tank having an internal space that communicates with the plurality of intake ports through the intake branch pipe and is filled with outside air. A main passage extending in a direction in which the intake branch pipes are separated from each other, and an EGR gas distribution pipe formed with a plurality of cylinder-specific introduction holes through which the main passage communicates with the plurality of intake ports through the plurality of intake branch pipes In the vicinity of a specific cylinder-specific introduction hole located at a specific position in the extending direction of the main passage among the plurality of cylinder-specific introduction holes, the main passage is arranged on a cross section of the EGR gas distribution pipe. It is characterized in that the protrusion that protrudes upward from the bottom inner wall surface positioned vertically lower side of the is provided.

  With this configuration, condensed water is generated from the EGR gas inside the EGR gas distribution pipe, and the condensed water on the inner bottom wall surface of the EGR gas distribution pipe flows to a specific position side of the EGR gas distribution pipe, for example, a specific position side. Even in a state in which the gas acts, the flow of the condensed water is hindered by a protrusion protruding upward in the vertical direction from the inner bottom wall surface of the EGR gas distribution pipe, and is condensed in a specific cylinder introduction hole of the EGR gas distribution pipe Concentrated water inflow is suppressed. Therefore, it is possible to reliably prevent misfiring or the like from occurring in a specific cylinder, and to prevent generation of vehicle vibration due to engine torque fluctuation.

  In the intake device for an internal combustion engine of the present invention having the above configuration, (2) the specific cylinder introduction hole is located on one end side in the extending direction of the main passage, and the protrusion is the specific cylinder. It is preferable that a barrier extending in the cross-sectional direction of the EGR gas distribution pipe is included between the adjacent cylinder-specific introduction hole adjacent to the separate introduction hole and the specific cylinder-specific introduction hole.

  In this case, by providing a barrier between the cylinder-by-cylinder introduction hole on one end side where the condensed water easily flows and the cylinder-by-cylinder introduction hole, the inflow of condensed water to the cylinder-by-cylinder introduction hole on one end side is suppressed. Therefore, the balance of the generated torque of the multi-cylinder engine is improved, and vehicle vibration due to engine torque fluctuation can be effectively suppressed.

  (3) The projection may include a plurality of barriers extending in the cross-sectional direction of the EGR gas distribution pipe between the plurality of cylinder introduction holes.

  Also in this case, by providing a barrier between a plurality of cylinder-specific introduction holes including a specific cylinder-specific introduction hole, the inflow of condensed water to the cylinder-specific introduction holes where the condensed water easily flows is effectively suppressed, The balance of torque generated by the multi-cylinder engine is improved.

  Alternatively, in the intake device for an internal combustion engine according to the present invention, (4) the projection portion is located at least one cylinder-introducing hole including the specific cylinder-introducing hole among the plurality of cylinder-introducing holes. It may include at least one set of one and other protrusions extending in the cross-sectional direction of the EGR gas distribution pipe on both sides in the extending direction of the passage.

  With this configuration, condensed water is generated from the EGR gas inside the EGR gas distribution pipe, and the condensed water on the inner bottom wall surface of the EGR gas distribution pipe flows to a specific position side of the EGR gas distribution pipe, for example, a specific position side. Even in a state in which the water is acting, the condensate flows into the specific cylinder from the EGR gas distribution pipe while the condensate is blocked from flowing into the specific cylinder introduction hole. Is suppressed. Therefore, it is possible to reliably prevent misfire or the like from occurring in a specific cylinder, and it is possible to prevent generation of vehicle vibration due to engine torque fluctuation. The one and the other protrusions may extend from the inner bottom wall surface of the main passage to the upper wall surface in the vertical direction, or on the inner bottom wall surface or the upper wall surface in the vertical direction. They may be connected to each other.

  In the intake device for an internal combustion engine having the above configuration (2) or (3), (5) the protrusion includes the barrier and the specific cylinder-specific introduction hole among the plurality of cylinder-specific introduction holes. It is preferable that at least one set of one and the other ridges extending in the cross-sectional direction of the EGR gas distribution pipe are respectively included on both sides in the extending direction of the main passage with respect to at least one cylinder-specific introduction hole including .

  With this configuration, even when the condensed water condensed on the inner bottom wall surface of the EGR gas distribution pipe flows into a specific position side of the EGR gas distribution pipe, the flow of the condensed water is reduced. When the acceleration is such that the condensate flows to a specific position of the EGR gas distribution pipe while being hindered by a barrier projecting vertically upward from the inner bottom wall surface of the pipe, the condensate is introduced for each specific cylinder. Concentrated inflow into the hole is obstructed by the protrusion. Therefore, it is possible to effectively prevent the condensed water from concentrating and flowing into the specific cylinder from the EGR gas distribution pipe, and to surely prevent the occurrence of torque fluctuation and the accompanying vehicle vibration caused by misfire in the specific cylinder. An intake device for an internal combustion engine can be provided.

  Further, in the intake device for an internal combustion engine having the configuration of (5) above, (6) the height of the barrier on the inner bottom wall surface is higher than the height of the one and the other protrusions on the inner bottom wall surface. It is desirable that it is also higher.

  In this case, it is reliably blocked by the barrier that the condensed water flows to the specific position side of the EGR gas distribution pipe, and outside the barrier, the condensed water is separated by cylinders on the specific position side by the protrusions on both sides of the cylinder-specific introduction holes. Concentrated inflow into the introduction hole is hindered.

  In any of the internal combustion engine intake devices described above, (7) the EGR gas distribution pipe may be made of a resin, for example, preferably made of a polyamide resin. With this configuration, even if acidic condensate accumulates inside the EGR gas distribution pipe, it is more resistant to corrosion than when it is made of aluminum or the like, and corrosion of the EGR gas distribution pipe can be suppressed.

  According to the present invention, even in a state where an acceleration is applied to cause the condensed water on the inner bottom wall surface of the EGR gas distribution pipe generated from the EGR gas to flow to a specific position side of the EGR gas distribution pipe, the condensed water The flow is obstructed by a protrusion protruding upward in the vertical direction from the inner bottom wall surface of the EGR gas distribution pipe, so that the condensed water is prevented from concentrating and flowing into a specific cylinder introduction hole of the EGR gas distribution pipe. Therefore, it is possible to effectively suppress the occurrence of misfire or the like in a specific cylinder, and to provide an intake device for an internal combustion engine that can reliably prevent deterioration of vehicle drivability due to vehicle vibration caused by engine torque fluctuation. be able to.

1 is a schematic configuration diagram of an intake device for an internal combustion engine according to a first embodiment of the present invention, in which FIG. 1 (a) is a schematic perspective view of an intake branch pipe portion of the intake manifold, and FIG. 1 (b) is an EGR gas distribution pipe; FIG. 1C is an IC-IC cross-sectional view of FIG. 1B. FIG. 2A is a side view of the intake manifold constituting the intake device for the internal combustion engine according to the first embodiment of the present invention, and FIG. 2B is a cross-sectional view taken along the line IIB-IIB in FIG. It is. FIG. 3A is a partial plan sectional view showing the arrangement of the protrusions on the inner wall surface of the EGR gas distribution pipe in the intake device for the internal combustion engine according to the first embodiment of the present invention, and FIG. It is a fragmentary top sectional view of the other mode from which arrangement | positioning of the projection part differs in the intake device of the internal combustion engine which concerns on 1st Embodiment. 1 is a cross-sectional view showing a schematic configuration of an internal combustion engine equipped with an intake device for an internal combustion engine according to a first embodiment of the present invention. It is sectional drawing in the division body joint surface of the intake manifold which comprises the intake device of the internal combustion engine which concerns on 2nd Embodiment of this invention, and is the figure seen from the IIB-IIB arrow direction of Fig.2 (a). It is sectional drawing in the division body joint surface of the intake manifold which comprises the intake device of the internal combustion engine which concerns on 3rd Embodiment of this invention, and is the figure seen from the IIB-IIB arrow direction of Fig.2 (a). It is sectional drawing in the division body joint surface of the intake manifold which comprises the intake device of the internal combustion engine which concerns on 4th Embodiment of this invention, and is the figure seen from the IIB-IIB arrow direction of Fig.2 (a).

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

(First embodiment)
1 to 4 show an intake device for an internal combustion engine according to a first embodiment of the present invention.

  In this embodiment, a spark ignition type internal combustion engine, for example, an in-line four-cylinder four-cycle gasoline engine (internal combustion engine) is mounted on a vehicle body (not shown) in a horizontal position.

  First, the configuration will be described.

  An engine 10 shown in FIG. 4 includes a head cover 11, a cylinder head 12, a cylinder block 13, and a crankcase 14, and a plurality of cylinders 13a (only one is shown in FIG. 4). A plurality of cylinders 15 are formed.

  A piston 16 is accommodated in each cylinder 15, and although not shown in detail, a crankshaft 17 in the crankcase 14 is connected to the piston 16 via a connecting rod 18. Also, a known valve operating mechanism 20, an ignition device 23, an injector 24, and the like are housed in the cylinder head 12, and the valve operating mechanism 20 is based on power from the crankshaft 17 or interlocks with the crankshaft 17. Independently driven.

  A plurality of sets of intake ports 12 a and exhaust ports 12 b are formed in the cylinder head 12 corresponding to the plurality of cylinders 15, and the valve operating mechanism 20 responds to the displacement of the piston 16 and the intake valves 21 and the exhaust valves. When the volume of the combustion chamber 10a formed in the upper part of the piston 16 in each cylinder 15 is changed by the rotation of the crankshaft 17 and the crankshaft 17 rotates, the combustion chamber 10a enters the combustion chamber 10a through the intake passage 31 and the intake port 12a. Air is sucked and exhaust gas after combustion in the combustion chamber 10 a is exhausted through the exhaust port 12 b and the exhaust passage 41.

  Here, the intake passage 31 includes a throttle body 33 that accommodates the throttle valve 32 so as to be pivotable (open / close operation), and an upstream intake duct provided on the upstream side and the downstream side of the throttle body 33, respectively. 34 and an intake manifold 35 on the downstream side. An air cleaner (not shown) is mounted on the upstream side of the intake duct 34, and air from which dust or the like has been removed by this air cleaner is taken into the intake duct 34 on the upstream side.

  As shown in FIGS. 1 and 4, the intake manifold 35 is provided corresponding to the plurality of intake ports 12 a of the engine 10, and a plurality of intake branch pipes 36 a, 36 b, 36 c, 36 d that are separated from each other, and the intake duct 34. And a surge tank 37 formed with an internal space 37a for introducing and filling outside air through the manifold, and the internal space 37a of the surge tank 37 passes through a plurality of intake branch pipes 36a to 36d to form a plurality of intake ports 12a. The cylinder head 12 forming a plurality of intake ports 12a is fastened and fixed by bolts (not shown) so as to communicate with each other. The intake manifold 35 is configured so that air introduced into the surge tank 37 through the intake duct 34 and filled can be sequentially taken into the plurality of intake ports 12a through the plurality of intake branch pipes 36a to 36d.

  The exhaust passage 41 is provided corresponding to the plurality of exhaust ports 12b formed in the cylinder head 12, and is provided to the plurality of exhaust ports 12b through the plurality of exhaust branch tubes 42b. A cylinder head 12 that forms a plurality of exhaust ports 12b of the engine 10 is formed inside an exhaust manifold 42 that is integrated with a collecting pipe portion 42c that communicates with and is connected to a downstream exhaust pipe (not shown). Fastened and fixed by bolts (not shown).

  On the other hand, the engine 10 includes an EGR device 50 that recirculates and recirculates part of the exhaust gas from the exhaust manifold 42 side to the intake manifold 35 side, and exhausts a part of the exhaust gas of the engine 10 by the EGR device 50. The refrigerant can be recirculated from the passage 41 side to the intake passage 31 side.

  The EGR device 50 has an EGR gas passage 51 that bypasses the combustion chamber 10a in each cylinder 15 of the engine 10 and extends from the exhaust passage 41 in the exhaust manifold 42 to the intake passage 31 in the intake manifold 35. In the middle of the EGR gas passage 51, an electromagnetic EGR valve 52 that adjusts the recirculation amount of the EGR gas and an EGR cooler 53 that cools the EGR gas that passes through the EGR gas passage 51 are provided.

  The EGR gas passage 51 is an exhaust gas recirculation passage that recirculates part of the exhaust gas as EGR gas from the exhaust passage 41 side to the intake passage 31 side of the engine 10, and a part of the EGR gas passage 51 is an EGR cooler 53. It is the EGR gas cooling passage inside. The EGR valve 52 can be switched between an open state in which the EGR gas passage 51 is communicated with the intake passage 31 side and a closed state in which the communication / connection state is limited, for example, shut off. Further, although not shown in detail, the EGR cooler 53 has a cooling water passage through which the cooling water after passing through the water jacket of the engine 10 passes and a gas passage through which EGR gas from the exhaust passage 41 side passes. It is a heat exchanger, and the EGR gas can be cooled by heat exchange between the cooling water from the engine 10 and the EGR gas from the exhaust passage 41 side.

  As shown in FIG. 4, an EGR valve 52 is interposed between the EGR cooler 53 disposed on the exhaust manifold 42 side and the intake manifold 35 so as to extend from the EGR valve 52 to the intake manifold 35. An EGR gas recirculation pipe 54 (not shown in detail) is provided, and an acid-resistant EGR gas distribution pipe 60 formed from a resin such as polyamide resin (for example, nylon) is provided closer to the intake manifold 35 than the EGR gas recirculation pipe 54. The intake manifold 35 is integrally mounted.

  As shown in FIG. 1 and FIG. 2, the EGR gas distribution pipe 60 extends in the direction in which the plurality of intake branch pipes 36a to 36d are separated from each other (the direction of arrow D in FIG. 1A). A substantially straight main passage 61 that forms a downstream portion of the gas passage 51, and a plurality of cylinder-specific introduction holes 62a, 62b that connect the main passage 61 to the plurality of intake ports 12a through the plurality of intake branch pipes 36a to 36d, An EGR distribution passage composed of 62c and 62d is formed. The plurality of cylinder-specific introduction holes 62a to 62d pass through the wall surface of the EGR gas distribution pipe 60 that defines the main passage 61 so as to communicate with the corresponding intake branch pipes 36a to 36d. They are formed substantially parallel to each other at a predetermined interval.

  The EGR gas distribution pipe 60 has a non-circular cross section that forms the main passage 61, for example, a bottomed cylindrical shape having a substantially triangular cross section, and has an inner wall surface 63. The inner wall surface 63 includes a first side wall surface 63a facing the opening edge of the plurality of cylinder-specific introduction holes 62a to 62d, a substantially flat inner bottom wall surface 63b positioned on the lower side in the vertical direction of the main passage 61, and A second side wall surface 63c having a bent or curved cross-sectional shape in which a plurality of cylinder-specific introduction holes 62a to 62d are opened on the lower side, and inner end surfaces 63d, 63e positioned at both ends in the extending direction D of the main passage 61 ( 2 (see FIG. 2B).

  Further, as shown in FIG. 2A, the intake manifold 35 is divided into two concave divided bodies 35a and 35b at the position of the cross section taken along the line IIB-IIB in FIG. A main portion 60a of an EGR gas distribution pipe 60 having a plurality of cylinder-specific introduction holes 62a to 62d is integrally formed in one divided body 35a disposed on the cylinder head 12 side in 35b. And with respect to the main part 60a of this EGR gas distribution pipe 60, it extends in the extending direction of the main passage 61 so as to form the first side wall surface 63a on the other divided body 35b side from the position of the section taken along the arrow IIB-IIB. The lid-like remaining portion 60b is integrally fixed to the other divided body 35b side. The other divided body 35b is in pressure contact with the outer peripheral seal portion 35s and the EGR chamber seal portion 60s of the one divided body 35a, and at the weld joint 64 located near the center of the EGR gas distribution pipe 60. Are integrally coupled to the divided body 35a and sealed. Needless to say, the EGR gas distribution pipe 60 may be configured as a tubular body that can be attached to and detached from the intake manifold 35.

  Among the plurality of cylinder introduction holes 62a to 62d of the EGR gas distribution pipe 60, at least a specific position in the extending direction of the main passage 61, for example, one end side (specific position side) away from the EGR gas inlet 61i of the main passage 61. In the vicinity of the cylinder-by-cylinder introduction hole 62a, there is a protruding height that protrudes upward in the vertical direction from the inner bottom wall surface 63b located on the lower side in the vertical direction of the main passage 61 on the cross section of the EGR gas distribution pipe 60. Different types of protrusions 65 and 66 are provided.

  The first protrusion 65 having a large protrusion height among the plurality of kinds of protrusions 65 and 66 is at least one cylinder on one end side of the main passage 61 away from the EGR gas inlet 61i (see FIG. 1A). A cross-section of the EGR gas distribution pipe 60 (see FIG. 1 (B)) between the inward cylinder-by-cylinder introduction hole 62b (adjacent cylinder-by-cylinder introduction hole) adjacent to the introduction hole 62a and the one-cylinder introduction hole 62a. The rib-shaped barrier of the substantially square cross section extended in the direction of b) reference is comprised (refer FIG.1 (c) and FIG.2 (b)).

  As shown in FIG. 2B and FIG. 3A, in the present embodiment, the first protrusion 65 is disposed in the middle between each pair of adjacent cylinder introduction holes 62a to 62d. A plurality of parallel barriers each extending in the cross-sectional direction of the EGR gas distribution pipe 60 (that is, orthogonal to the extending direction of the main passage 61) are configured. Further, the EGR chamber, which is a space in the EGR gas distribution pipe 60, has a plurality of regions Zc having substantially the same length (substantially the same volume) corresponding to the plurality of cylinder introduction holes 62a to 62d by the plurality of first protrusions 65. It is divided into.

  On the other hand, the second protrusion 66 has at least one cylinder-by-cylinder introduction hole including a cylinder-by-cylinder introduction hole 62a on one end side of the main passage 61 among the plurality of cylinder-by-cylinder introduction holes 62a to 62d, for example, a plurality of cylinder-by-cylinder introduction holes. For each of 62a to 62d, at least one set of one and the other parallel triangular ribs (rib-shaped protrusions) extending in the cross-sectional direction of the EGR gas distribution pipe 60 on both sides in the extending direction of the main passage 61, respectively. ). The second protrusion 66 serving as one and the other protrusions may extend from the inner bottom wall surface 63b of the main passage 61 to the upper wall surface in the vertical direction. They may be connected to each other on the bottom wall surface 63b or on the wall surface on the upper side in the vertical direction.

  Further, as shown in FIGS. 2B and 3A, in the present embodiment, the second protrusion 66 extends the main passage 61 with respect to each of the plurality of cylinder introduction holes 62a to 62d. A plurality of sets, for example, 5 sets of one and the other parallel ribs located on both sides of the direction are formed.

  Here, the protrusion height h1 at which the first protrusion 65 protrudes upward in the vertical direction from the inner bottom wall surface 63b of the EGR gas distribution pipe 60 is the same as the inner bottom wall surface of the EGR gas distribution pipe 60. It is larger than the protrusion height h2 protruding upward in the vertical direction from 63b, for example, about twice the protrusion height h2.

  In the present embodiment, the second protrusion 66 is not formed at a position where the cylinder-specific introduction holes 62a to 62d open to the main passage 61 (EGR chamber), and the cylinder-specific introduction holes 62a to 62d. The pair of second protrusions 66 that are closest to each other are spaced apart from each other by a distance greater than the opening diameter of each cylinder-introducing hole 62a to 62d to the main passage 61.

  However, as shown in FIG. 3B, between the pair of second protrusions 66 closest to the cylinder-specific introduction holes 62a to 62d, the main passage 61 of the cylinder-specific introduction holes 62a to 62d is provided. A third protrusion 67 shortened by cutting away a distance d3 (> d1) of the pair of second protrusions 66 about a distance d3 (> d1) or more from the pair of second protrusions 66 may be provided. .

  Further, in the first protrusion 65, the protrusion height h1 as a barrier on the inner bottom wall surface 63b of the EGR gas distribution pipe 60 is higher than the protrusion height h2 of the second protrusion 66 on the inner bottom wall surface 63b. In addition to being higher, it has a barrier width w1 that is sufficiently larger than the width of the top of each of the second protrusions 66. However, the second protrusions 66 are spaced apart from each other in the extending direction of the main passage 61 so that the tops of the plurality of parallel rib-like second protrusions 66 are convex, and the plurality of parallel rib-like second parts are formed. The parallel uneven portions 68L and 68R having recesses between the bottom portions of the protrusions 66 are formed in the uneven forming range W wider than the barrier width w1.

  The parallel uneven portions 68L and 68R and the first protrusion 65 adjacent to the parallel uneven portions 68L and 68R are separated from each other by a separation distance d2 sufficiently larger than the separation distance d1 of the plurality of parallel rib-shaped second protrusions 66.

  By the way, the EGR gas distribution pipe 60 is made of a material resistant to acidic condensed water generated from EGR gas, for example, polyamide resin, and at least a part of the divided bodies 35a, 35 of the intake manifold 35 forming a part thereof. Is also formed from a polyamide resin.

  Such a configuration of the EGR gas distribution pipe 60 of the present embodiment is such that the main passage 61 is provided for each of the plurality of cylinder introduction holes 62a to 62d, for example, for each cylinder introduction hole 62a on one end side of the main passage 61. The EGR gas flow from the exhaust gas to the intake passage 31 side can be easily performed, but the flow from the main passage 61 of the condensed water generated in the EGR gas distribution pipe 60 toward the intake passage 31 side becomes difficult. In particular, even when condensed water concentrates on one end side of the EGR gas distribution pipe 60 due to turning G of the vehicle or the like, the concentrated condensed water flows into the intake passage 31 in a concentrated manner from the cylinder-specific introduction hole 62a on one end side. This is what suppresses this.

  The passage cross-sectional areas and lengths of the plurality of cylinder-specific introduction holes 62a to 62d indicate the flow rate of EGR gas passing through the plurality of cylinder-specific introduction holes 62a to 62d according to the shape of the EGR gas distribution pipe 60 and usage conditions. Each is set to an optimal value to make it even. That is, the plurality of cylinder-specific introduction holes 62a to 62d have substantially the same diameter and length, but strictly speaking, they are adjusted to the optimum diameter and length in order to equalize the flow rates of the respective EGR gases.

  Further, since blowby gas leaks from the combustion chamber 10a through the gap between the cylinder 13a and the piston 16 into the internal space of the crankcase 14, the engine 10 prevents deterioration of the engine oil and corrosion inside the engine 10. For example, a PCV blowby gas reduction device (not shown) that forcibly ventilates the inside of the crankcase 14 is provided, and as shown in FIG. At least one ventilation passage 10v that connects the inner space of 12 and the inner space of the crankcase 14 is formed. Further, between the head cover 11 of the engine 10 and the upstream intake duct 34, fresh air from the intake passage 31 upstream of the throttle valve 32, that is, air that can introduce new air into the engine 10. An introduction pipe 39 is interposed between the inside of the head cover 11 and the surge tank 37, and a blow-by gas recirculation pipe (not shown) that recirculates the blow-by gas generated inside the engine 10 to the downstream side of the throttle valve 32. A PCV valve is interposed.

  Further, in the present embodiment, the engine 10 is controlled by an ECU (electronic control unit) (not shown), and the EGR valve 52 is controlled according to the operating state. The EGR device 50 is configured to operate even at high output in order to increase the fuel consumption and achieve both low fuel consumption and high output. Therefore, the EGR use range in the operation region of the engine 10 is set wide.

  Further, as shown in FIG. 2B, a plurality of bolt holes through which bolts (not shown) for fastening the one divided body 35a to the cylinder head 12 are passed through the upper end portion of the one divided body 35a. 35h is formed. A throttle body 33 including a throttle valve 32 is attached to a lower end portion of one divided body 35a, and an intake pressure sensor 38 is attached.

  Next, the operation of this embodiment will be described.

  In the internal combustion engine intake device of the present embodiment configured as described above, when the engine 10 is operated, the EGR valve 52 is controlled according to the operating state, and when the EGR valve 52 is opened, the exhaust gas of the engine 10 is controlled. Part of the exhaust gas recirculates from the exhaust passage 41 side to the intake passage 31 side, thereby reducing the NOx component in the exhaust gas. In addition, since the EGR device 50 having the EGR cooler 53 operates even at high output, both low fuel consumption and high output can be achieved.

  During the operation of the engine 10, moisture contained in the EGR gas is condensed inside the EGR gas distribution pipe 60, and condensed water is generated from the EGR gas. Further, condensed water is generated in the EGR gas passage 51 upstream of the EGR gas distribution pipe 60, for example, in the EGR cooler 53, and condensed water can also be generated in the EGR valve 52 or the EGR gas recirculation pipe 54. In particular, in an operation state in which the cooling water temperature of the engine 10 is low and the cooling capacity of the EGR cooler 53 is high, such as a short time after the start of the engine 10, particularly in an operation state in which the intake air temperature is low, the temperature is relatively low. The EGR gas cooled in the EGR gas distribution pipe 60 is likely to generate condensed water, and a state in which a large number of water droplets adhere to the inner wall surface 63 of the EGR gas distribution pipe 60 can be obtained.

  On the other hand, when the vehicle on which the engine 10 is mounted travels, the condensed water (many water droplets) on the inner bottom wall surface 63b of the EGR gas distribution pipe 60 is transferred to one end side or the other end side (specific position side) of the EGR gas distribution pipe 60. There may be a state in which acceleration such as flowing in the air acts. In the present embodiment, since the engine 10 is mounted horizontally on the vehicle, for example, when the vehicle is turning or turning, the cylinder-by-cylinder introduction hole 62a on one end side or the cylinder-by-cylinder introduction hole on the other end side. A state in which condensed water tends to concentrate and flow into 62d may occur.

  In this state, the condensed water inside the EGR gas distribution pipe 60 tends to concentrate on one end side or the other end side of the EGR gas distribution pipe 60. Even in a state where acceleration is applied so that the condensed water on the wall surface 63b flows to the end side of the EGR gas distribution pipe 60, a plurality of types projecting upward in the vertical direction from the inner bottom wall surface 63b of the EGR gas distribution pipe 60 The projections 65 and 66 prevent the concentrated flow into the cylinder-specific introduction holes 62a or 62d on the end side.

  That is, in the present embodiment, the first protrusion 65 is located between the inner cylinder-side introduction hole 62b adjacent to the one-end cylinder-by-cylinder introduction hole 62a and the one-end-side cylinder-by-cylinder introduction hole 62a. Since this is a barrier extending in the cross-sectional direction of the EGR gas distribution pipe 60, the conventional cylinder-by-cylinder introduction hole 62a and other cylinder-by-cylinder introduction are likely to be caused by concentrating condensed water due to swirl G or the like at low temperatures. By providing the first protrusion 65 as a barrier between the hole 62b and the like, the inflow of condensed water to the cylinder-by-cylinder introduction hole 62a on one end side is effectively suppressed. Moreover, the second protrusion 66 has one of a plurality of sets extending in the cross-sectional direction of the EGR gas distribution pipe 60 on both sides in the extending direction of the main passage 61 with respect to each of the plurality of cylinder introduction holes 62a to 62d. Since the other protrusion is formed, the condensed water generated from the EGR gas inside the EGR gas distribution pipe 60 is formed by the first protrusions 65 that are a plurality of barriers. It is blocked from coming out (or from between the projection 65 at the end and the wall surface at the end of the EGR gas distribution pipe 60), and is distributed substantially evenly corresponding to the plurality of cylinder introduction holes 62a to 62d. The state is maintained, and a flow that concentrates on one end side or the other end side of the main passage 61 does not occur. Therefore, the concentrated water is prevented from concentrating and flowing into the specific cylinder introduction hole 62a or 62d of the EGR gas distribution pipe 60, and the concentrated condensed water flows into the specific cylinder and may cause misfire. It will be effectively suppressed. As a result, the balance of the generated torque of the multi-cylinder engine 10 is improved, and vehicle vibration due to torque fluctuations of the engine 10 can be effectively suppressed.

  Furthermore, in the present embodiment, the first protrusion 65 and the second protrusion 66 as a whole include a plurality of first protrusions 65 that are a plurality of parallel barriers that are spaced apart at substantially equal intervals. EGR gas distribution pipes 60 on both sides in the extending direction of the main passage 61 with respect to each of the plurality of cylinder introduction holes 62a to 62d including the cylinder introduction hole 62a on one end side of the cylinder introduction holes 62a to 62d. The second projection 66, which is at least one set of one and the other ridges extending in the cross-sectional direction, includes the condensed water condensed on the inner bottom wall surface 63b of the EGR gas distribution pipe 60. Even when acceleration is applied to the end side of the pipe 60, the flow of the condensed water is a first barrier as a barrier that protrudes upward in the vertical direction from the inner bottom wall surface 63 b of the EGR gas distribution pipe 60. Protrusion 65 Therefore, not only is it inhibited, but the condensed water flows into each of the plurality of cylinder-by-cylinder introduction holes 62a to 62d and is also inhibited by the second protrusions 66 of the respective one and the other parallel rib strips. The Therefore, it is more reliably prevented that misfire or the like is likely to occur in a specific cylinder due to the concentrated flow of condensed water from the EGR gas distribution pipe 60 into the specific cylinder 15. It is possible to provide an intake device for an internal combustion engine that can reliably prevent generation.

  In addition, in this embodiment, the protrusion height h1 of the first protrusion 65 as a barrier on the inner bottom wall surface 63b of the EGR gas distribution pipe 60 is set as one and the other protrusions on the inner bottom wall surface 63b. Since the protrusion height h2 of the second protrusion 66 is higher, the protrusion width w1 of the first protrusion 65 is sufficiently larger than the top width of the second protrusion 66. Therefore, the flow of the condensed water to the end portion side of the EGR gas distribution pipe 60 is reliably inhibited by the first protrusions 65 as a plurality of barriers, and each region partitioned by the first protrusions 65 Inside (including the region outside the first protrusion 65 as the outermost barrier), the condensed water is supplied to the cylinder by the second protrusion 66 as the protrusion on both sides of each cylinder introduction hole 62a and the like. Concentrate on the separate introduction hole 62a, etc. It is more effectively suppressed, inhibited. Therefore, in any cylinder of the engine 10, the condensed water does not flow in a concentrated manner, and the probability that the condensed water is sucked into the cylinder in a state where it is evaporated again increases.

  In the present embodiment, since the EGR gas distribution pipe 60 is made of polyamide resin, even if acidic condensed water is accumulated inside the EGR gas distribution pipe 60, the EGR gas distribution pipe 60 is more resistant to corrosion than the case where it is made of aluminum or the like. The corrosion of the EGR gas distribution pipe 60 can be effectively suppressed.

  As described above, in this embodiment, there is an acceleration that causes the condensed water flowing from the EGR gas distribution pipe 60 on the inner bottom wall surface 63b of the EGR gas distribution pipe 60 to flow toward the end side of the EGR gas distribution pipe 60. However, the flow of the condensed water is hindered by a plurality of kinds of projections 65 and 66 projecting upward in the vertical direction from the inner bottom wall surface 63b of the EGR gas distribution pipe 60, and the EGR gas distribution pipe 60 is introduced for each specific cylinder. Condensed water is prevented from concentrating and flowing into the holes 62a and the like, so that it is possible to effectively suppress misfires and the like in a specific cylinder of the engine 10 and to prevent vehicle vibration caused by torque fluctuations of the engine 10. It is possible to provide an intake device for an internal combustion engine that can reliably prevent generation and the like.

  In the present embodiment, the inside of the EGR gas distribution pipe 60 is partitioned into a plurality of substantially equal-length regions Zc by a plurality of first protrusions 65 disposed in the middle of the plurality of cylinder-specific introduction holes 62a to 62d. However, the arrangement intervals of the plurality of first protrusions 65 can be made different so that the volumes of the plurality of regions Zc are made different at an appropriate ratio. In addition, the height and width of the central first protrusion 65 among the plurality of first protrusions 65 can be reduced. Further, the first protrusion 65 is provided only between the specific cylinder-specific introduction hole and the other cylinder-specific introduction hole, where the condensed water easily flows in if there is no barrier among the plurality of cylinder-specific introduction holes 62a to 62d. Thus, the other first protrusion 65 may be omitted.

(Second Embodiment)
FIG. 5 is a view showing an intake device for an internal combustion engine according to the second embodiment of the present invention.

  Each embodiment described below has an overall configuration substantially similar to that of the above-described first embodiment, and only the internal shape of the EGR gas distribution pipe is different from that of the first embodiment. Therefore, here, only the configuration of the main part of the intake device of the internal combustion engine according to the second embodiment is shown in FIG. 5, and the other configurations correspond to the configurations of the first embodiment shown in FIGS. The configuration of the main part will be described using the reference numerals of the elements.

  In the present embodiment, as shown in FIG. 5, at least a specific position in the extending direction of the main passage 61 among the plurality of cylinder introduction holes 62 a to 62 d of the EGR gas distribution pipe 60, for example, EGR gas introduction in the main passage 61. From the inner bottom wall surface 63b located on the lower side in the vertical direction of the main passage 61 on the cross section of the EGR gas distribution pipe 60 toward the upper side in the vertical direction in the vicinity of the cylinder-by-cylinder introduction hole 62a on the one end side away from the port 61i. A plurality of second projecting portions 66 projecting out are provided.

  However, the thing corresponding to the 1st projection part 65 in a 1st embodiment is not provided.

  The plurality of second protrusions 66 are at least one cylinder-specific introduction hole including the cylinder-specific introduction hole 62a on one end side (specific position side) of the main passage 61 among the plurality of cylinder-specific introduction holes 62a to 62d. At least one set of parallel ribs (rib-like ridges) having a substantially triangular cross-section extending in the transverse cross-sectional direction of the EGR gas distribution pipe 60 is formed on both sides of the main passage 61 in the extending direction. Specifically, in the present embodiment, the second protrusion 66 has a plurality of sets, for example, five sets, located on both sides in the extending direction of the main passage 61 with respect to each of the plurality of cylinder introduction holes 62a to 62d. One and the other parallel rib are comprised.

  The second protrusion 66 is not formed at a position where the cylinder-specific introduction holes 62a to 62d open to the main passage 61 (EGR chamber), and is closest to the cylinder-specific introduction holes 62a to 62d. The pair of second protrusions 66 are spaced apart from each other by a larger distance than the opening diameter of the cylinder-specific introduction holes 62a to 62d into the main passage 61. Between each pair of second protrusions 66 closest to each cylinder-introducing hole 62a to 62d, each pair of second-injection holes 62a to 62d is opened from the opening to the main passage 61. One or a plurality of third protrusions 67 (see FIG. 3B) are provided so as to be separated by a distance d3 that is approximately the distance d1 or more than the distance d1 of the protrusions 66.

  Further, the plurality of second protrusions 66 are spaced apart from each other in the extending direction of the main passage 61, and the tops of the plurality of parallel rib-like second protrusions 66 are convex, and the plurality of parallel rib-like protrusions 66 are convex. Parallel concavo-convex portions 68 </ b> L and 68 </ b> R are formed in the concavo-convex formation range W between the bottom portions of the second protrusions 66.

  One corresponding to each cylinder introduction hole, for example, one and the other parallel concave and convex portions 68L and 68R corresponding to one cylinder-side introduction hole 62a, and one cylinder corresponding to the adjacent cylinder introduction hole, for example, the inner cylinder-specific introduction hole 62b. And the other parallel uneven | corrugated | grooved part 68L and 68R is spaced apart the space | interval close | similar to the width | variety of the uneven | corrugated formation range W.

  Similarly to the first embodiment, the EGR gas distribution pipe 60 of the present embodiment is formed of a material that is resistant to acidic condensed water generated from EGR gas, for example, a polyamide resin, and an intake air that forms a part thereof. At least a part of the divided bodies 35a, 35 of the manifold 35 is also made of, for example, polyamide resin.

  Even in the present embodiment, even in a state where acceleration is applied such that the condensed water on the inner bottom wall surface 63b of the EGR gas distribution pipe 60 generated from the EGR gas flows to the specific position side of the EGR gas distribution pipe 60, The flow of the condensed water is blocked at a plurality of locations by a plurality of sets of projections 66 projecting upward in the vertical direction from the inner bottom wall surface 63b of the EGR gas distribution pipe 60, and the specific cylinder-specific introduction holes 62a of the EGR gas distribution pipe 60, etc. Therefore, it is possible to effectively prevent the occurrence of misfire in a specific cylinder of the engine 10 and to prevent the occurrence of vehicle vibration due to the torque fluctuation of the engine 10. An intake device for an internal combustion engine that can be reliably prevented can be provided.

(Third embodiment)
FIG. 6 is a view showing an intake device for an internal combustion engine according to the third embodiment of the present invention.

  Here, only the configuration of the main part of the intake device of the internal combustion engine according to the third embodiment is shown in FIG. 6, and the other configurations correspond to the configurations of the first embodiment shown in FIGS. The configuration of the main part will be described using the reference numerals of the elements.

  As shown in FIG. 6, in this embodiment, at least a specific position in the extending direction of the main passage 61 among the plurality of cylinder-specific introduction holes 62 a to 62 d of the EGR gas distribution pipe 60, for example, EGR gas introduction in the main passage 61 In the vicinity of the cylinder-by-cylinder introduction hole 62a on one end side away from the port 61i, on the cross section of the EGR gas distribution pipe 60, from the inner bottom wall surface 63b located on the lower side in the vertical direction of the main passage 61, to the upper side in the vertical direction. A plurality of first projecting portions 65 having different projecting heights are provided.

  The plurality of first protrusions 65 are provided with an inner cylinder-by-cylinder introduction hole 62b adjacent to at least one cylinder-side introduction hole 62a on one end side (specific position side) of the main passage 61 separated from the EGR gas introduction port 61i. A rib-shaped barrier having a substantially square cross section extending in the direction of the transverse cross section of the EGR gas distribution pipe 60 is formed between the cylinder-by-cylinder introduction hole 62a on one end side.

  Further, in the present embodiment, the first protrusion 65 is disposed in the middle between each pair of adjacent cylinder introduction holes 62a to 62d, and extends in the cross-sectional direction of the EGR gas distribution pipe 60 (that is, A plurality of parallel barriers (perpendicular to the extending direction of the main passage 61) are formed. The EGR chamber, which is a space in the EGR gas distribution pipe 60, is partitioned by a plurality of first protrusions 65 into a plurality of substantially equal-length regions Zc corresponding to the plurality of cylinder introduction holes 62a to 62d. .

  Even in the present embodiment, even in a state where acceleration is applied such that the condensed water on the inner bottom wall surface 63b of the EGR gas distribution pipe 60 generated from the EGR gas flows to the end side of the EGR gas distribution pipe 60, The flow of the condensed water is inhibited by a plurality of protrusions 65 as parallel barriers that protrude upward in the vertical direction from the inner bottom wall surface 63b of the EGR gas distribution pipe 60, and is prevented from exiting from the inside of each region Zc. As a result, the concentrated water is prevented from concentrating and flowing into the specific cylinder introduction holes 62a of the EGR gas distribution pipe 60, so that misfire or the like occurs in a specific cylinder of the engine 10. It is possible to provide an intake device for an internal combustion engine that can effectively suppress the occurrence of vehicle vibration due to torque fluctuation of the engine 10 and the like.

(Fourth embodiment)
FIG. 7 is a view showing an intake device for an internal combustion engine according to the fourth embodiment of the present invention.

  Here, only the configuration of the main part of the intake device of the internal combustion engine according to the fourth embodiment is shown in FIG. 7, and the other configurations correspond to the configurations of the first embodiment shown in FIGS. The configuration of the main part will be described using the reference numerals of the elements.

  As shown in FIG. 7, in the present embodiment, a specific position in the extending direction of the main passage 61 among the plurality of cylinder introduction holes 62 a to 62 d of the EGR gas distribution pipe 60, for example, the EGR gas introduction port of the main passage 61. From the inner bottom wall surface 63b located on the lower side in the vertical direction of the main passage 61 on the cross section of the EGR gas distribution pipe 60 in the vicinity of the cylinder-by-cylinder introduction hole 62a on one end side away from 61i, toward the upper side in the vertical direction. A protruding first protrusion 65 is provided.

  This first protrusion 65 is formed between the EGR gas inlet 62a on one end side of the main passage 61 away from the EGR gas inlet 61i and the cylinder inlet 62b on the inner side adjacent to the EGR gas. A rib-shaped barrier having a substantially rectangular cross section extending in the direction of the cross section of the distribution pipe 60 is formed.

  Further, the EGR chamber, which is a space in the EGR gas distribution pipe 60, has a narrow region Z1 on one end side corresponding to the cylinder-by-cylinder introduction hole 62a on the one end side and the other cylinder-by-cylinder introduction hole 62b. It is divided into a wide area Z2 on the other end side corresponding to ˜62d.

  Even in the present embodiment, even in the state where the acceleration that causes the condensed water on the inner bottom wall surface 63b of the EGR gas distribution pipe 60 generated from the EGR gas to flow to one end side of the EGR gas distribution pipe 60 is in effect. The flow of water is hindered by the first protrusion 65 as a barrier projecting vertically upward from the inner bottom wall surface 63b of the EGR gas distribution pipe 60, and condensed water concentrates in the narrow area Z1 from the wide area Z2. Inflow is inhibited. Therefore, the condensed water is prevented from concentrating and flowing into the specific cylinder introduction holes 62a of the EGR gas distribution pipe 60, and the occurrence of misfire or the like in the specific cylinder of the engine 10 is effectively suppressed. As a result, it is possible to provide an intake device for an internal combustion engine that can reliably prevent generation of vehicle vibration due to torque fluctuation of the engine 10.

  In the present embodiment, the first protrusion 65 is provided only between the cylinder-by-cylinder introduction hole 62a on one end side and the cylinder-by-cylinder introduction hole 62b on the other side. The first protrusion 65 may also be provided between the cylinder-by-cylinder introduction hole 62d and the inner cylinder-by-cylinder introduction hole 62c (adjacent cylinder-by-cylinder introduction hole) adjacent thereto. Depending on the inclination or the curved state of the main passage 61, it may be possible that the specific cylinder into which the condensed water easily flows without the projection is not the end-side cylinder. A first protrusion 65 as a barrier is provided between the cylinder-by-cylinder introduction hole and the cylinder-by-cylinder introduction hole 62d to the cylinder adjacent thereto. Further, the cross-sectional shape of the main passage 61 of the EGR gas distribution pipe 60 is not particularly limited, but it is preferable that the inner bottom wall surface 63b is wide as in the above-described embodiment.

  As described above, the present invention is in a state in which an acceleration that causes the condensed water on the inner bottom wall surface of the EGR gas distribution pipe generated from the EGR gas to flow to the specific position side of the EGR gas distribution pipe acts. The flow of the condensed water is obstructed by a protrusion protruding upward in the vertical direction from the inner bottom wall surface of the EGR gas distribution pipe, and the condensed water may concentrate and flow into a specific cylinder introduction hole of the EGR gas distribution pipe. Provided is an internal combustion engine intake device capable of effectively suppressing the occurrence of misfire or the like in a specific cylinder and reliably preventing the occurrence of vehicle vibrations due to engine torque fluctuations. An internal combustion engine equipped with a gas distribution introduction pipe that distributes and introduces a gas containing moisture and oil into an intake manifold that sucks air into each cylinder of the multi-cylinder internal combustion engine Useful in the intake devices in general.

10 engine (multi-cylinder engine, internal combustion engine)
12 Cylinder head 13 Cylinder block 15 Cylinder 20 Valve mechanism 31 Intake passage 33 Throttle body 34 Intake duct 35 Intake manifold 35a, 35b Split body 36a, 36b, 36c, 36d Intake branch pipe 37 Surge tank 50 EGR device 51 EGR gas passage 53 EGR cooler 60 EGR gas distribution pipe 61 Main passage 61i EGR gas introduction port 62a One cylinder side introduction hole (specific cylinder introduction hole)
62b, 62c Cylinder-specific introduction holes (adjacent cylinder-specific introduction holes; other cylinder-specific introduction holes)
62d Introducing hole for each cylinder on the other end side (introducing hole for each other cylinder; introducing hole for each specific cylinder)
63a 1st side wall surface 63b Inner bottom wall surface 63c 2nd side wall surface 63d, 63e Inner end surface 65 1st protrusion part (barrier)
66 Second protrusion (rib-shaped protrusion)
67 3rd protrusion 68L, 68R Parallel uneven part d1, d2 Separation distance d3 Distance h1, h2 Projection height w1 Barrier width (projection width)
Zc, Z1, Z2 region

Claims (7)

A plurality of intake branch pipes that are provided corresponding to a plurality of intake ports of a multi-cylinder internal combustion engine, and an internal space that communicates with the plurality of intake ports through the plurality of intake branch pipes and that is filled with outside air are formed. An intake device for an internal combustion engine having an intake manifold integrally formed with the surge tank,
A main passage extending in a direction in which the plurality of intake branch pipes are separated from each other, and an EGR gas component having a plurality of cylinder-specific introduction holes that communicate the main passages with the plurality of intake ports through the plurality of intake branch pipes With piping,
The vertical direction of the main passage on the cross section of the EGR gas distribution pipe is at least in the vicinity of the specific introduction hole for each cylinder located at a specific position in the extending direction of the main passage among the plurality of introduction holes for each cylinder. An intake device for an internal combustion engine, characterized in that a protrusion that protrudes upward from an inner bottom wall surface located on the lower side is provided. The specific cylinder-specific introduction hole is located on one end side in the extending direction of the main passage,
The protrusion includes a barrier extending in a cross-sectional direction of the EGR gas distribution pipe between an adjacent cylinder-specific introduction hole adjacent to the specific cylinder-specific introduction hole and the specific cylinder-specific introduction hole. The intake device for an internal combustion engine according to claim 1.   2. The intake device for an internal combustion engine according to claim 1, wherein the protrusion includes a plurality of barriers extending in a cross-sectional direction of the EGR gas distribution pipe between the plurality of cylinder-by-cylinder introduction holes. .   The projections cross the EGR gas distribution pipes on both sides in the extending direction of the main passage with respect to at least one cylinder-specific introduction hole including the specific cylinder-specific introduction hole among the plurality of cylinder-specific introduction holes. 2. An intake device for an internal combustion engine according to claim 1, further comprising at least one set of one and other protrusions extending in the surface direction.   The protrusion includes the barrier, and at least one of the plurality of cylinder introduction holes including the specific cylinder introduction hole on each side of the main passage in the extending direction of the main passage. 4. The intake device for an internal combustion engine according to claim 2, further comprising at least one set of one and other protrusions extending in a cross-sectional direction of the EGR gas distribution pipe. 5.   6. The intake device for an internal combustion engine according to claim 5, wherein a height of the barrier on the inner bottom wall surface is higher than a height of the one and the other protrusions on the inner bottom wall surface. .   The intake device for an internal combustion engine according to any one of claims 1 to 6, wherein the EGR gas distribution pipe is made of resin.

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