Intake Manifold

Abstract

To provide an intake manifold that can improve NV performance.SOLUTION: An intake manifold 10 comprises: a surge tank 21; and a plurality of branch pipes 23 individually connected to the surge tank 21, and distributing air inside the surge tank 21. The intake manifold 10 comprises a gas introduction part 25. The gas introduction part 25 has a structure inside which introduced gas other than air is passed, and introduces the introduced gas into the surge tank 21. The gas introduction part 25 is provided integrally with the surge tank 21 and the branch pipes 23 so as to connect an outer wall of the surge tank 21 and outer walls of the branch pipes 23.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an intake manifold for an internal combustion engine.

Background Art

[0002] An internal combustion engine is provided with an intake manifold forming part of an intake system (see Patent Document 1). This intake manifold includes a surge tank, an air introduction portion communicating the inside and outside of the surge tank, and a plurality of branch pipes each having one end connected to the surge tank. When the intake manifold is attached, the air introduction portion is connected to an intake passage on the upstream side in the intake flow direction. The plurality of branch pipes are also connected to respective intake ports of the internal combustion engine. Such an intake manifold distributes air drawn into the intake passage to each cylinder of the internal combustion engine.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] The intake manifold is arranged to connect the intake passage on the upstream side in the intake flow direction and the intake port of the internal combustion engine. Due to such arrangement constraints, the intake manifold ends up having a structure with a gap between the surge tank and the branch pipes. Since the rigidity of an intake manifold having such a structure tends to be low, its performance for suppressing vibration and noise (so-called NV performance) tends to be low.

Means for Solving the Problem

[0005] An intake manifold for solving the above problems comprises a surge tank and a plurality of branch pipes, each individually connected to the surge tank and distributing the air inside the surge tank, wherein the intake manifold has a gas introduction section that allows an introduced gas other than air to pass through and introduces the introduced gas into the part of the intake manifold where air flows, and the gas introduction section is provided integrally with the surge tank and the branch pipes in such a manner that it connects the outer wall of the surge tank and the outer wall of the branch pipes.

[0006] According to the above configuration, the structure of the intake manifold can be designed so that the surge tank and branch pipes support each other via a gas inlet. This allows for higher rigidity of the intake manifold compared to those without such a gas inlet, thereby improving NVH performance. [Brief explanation of the drawing]

[0007] [Figure 1] This is a perspective view of one embodiment of an intake manifold. [Figure 2] This is a side view of the intake manifold. [Figure 3] This is a disassembled side view of the intake manifold. [Figure 4] This is a side cross-sectional view of the intake manifold along line 4-4 in Figure 1. [Figure 5] These are side views of the first and second components of the intake manifold. [Figure 6] This is a side view of the third component of the intake manifold. [Figure 7] These are side views of the first and second components of the modified intake manifold. [Modes for carrying out the invention]

[0008] Hereinafter, one embodiment of the intake manifold will be described with reference to Figures 1 to 6. In this embodiment, the vertical direction in Figure 2 will be considered the vertical direction of the intake manifold 10, the left-right direction in Figure 2 will be considered the front-to-back direction of the intake manifold 10, and the direction perpendicular to the plane of the paper in Figure 2 will be considered the left-to-right direction of the intake manifold 10.

[0009] As shown in Figures 1 to 3, the intake manifold 10 is composed of three divided parts (first member 11, second member 12, and third member 13) separated in the front-rear direction. These first member 11, second member 12, and third member 13 are all made of a rigid synthetic resin material. The intake manifold 10 has a structure in which the first member 11, second member 12, and third member 13 are stacked on top of each other (as shown in Figure 2), and these members 11 to 13 are fixed to each other by vibration welding.

[0010] As shown in Figures 1 to 4, the intake manifold 10 includes a surge tank 21, an air inlet 22, a plurality (two in this embodiment) of branch pipes 23, a mounting flange 24, and a gas inlet 25.

[0011] <Surge Tank> The surge tank 21 forms the lower part of the intake manifold 10. The surge tank 21 functions as a volumetric section for temporarily storing air.

[0012] <Air intake section> As shown in Figures 1, 2, and 5, the air intake section 22 is a passage that connects the inside of the surge tank 21 to the outside of the intake manifold 10. The air intake section 22 is connected to the left side of the surge tank 21. The air intake section 22 extends from the bottom of the intake manifold 10 towards the rear and diagonally upward. The right side of the air intake section 22 is connected to the left side of the surge tank 21. The upper part of the air intake section 22 is a fixed section 221 to which the upstream side of the intake airflow direction in the intake passage of the internal combustion engine (specifically, the throttle mechanism) is fixed. In the intake manifold 10, air is introduced into the inside of the surge tank 21 via the air intake section 22.

[0013] A sensor passage 26 is provided in the air intake section 22. The sensor passage 26 extends in a manner that it protrudes rearward from the rear wall (hereinafter referred to as the rear wall 22R) of the air intake section 22. The front end of the sensor passage 26 is open on the inner surface of the rear wall 22R of the air intake section 22. The rear end of the sensor passage 26 is closed. A pressure sensor 27 is attached to the sensor passage 26. This pressure sensor 27 detects the internal pressure of the sensor passage 26 as the internal pressure of the intake manifold 10.

[0014] <Branch pipe> As shown in Figures 2 and 4-6, the multiple branch pipes 23 are individually connected to the lower part of the surge tank 21. The multiple branch pipes 23 are distribution passages that distribute the air inside the surge tank 21. Each branch pipe 23 extends from the lower rear to the upper front of the intake manifold 10 in a curved shape that is convex toward the rear. The base end 231 portion of each branch pipe 23 is formed integrally with the rear wall portion (hereinafter referred to as the rear wall 21R) of the surge tank 21 without any gaps. The base end 231 of each branch pipe 23 opens on the inner surface of the rear wall 21R of the surge tank 21. The tip 232 of each branch pipe 23 opens toward the outside.

[0015] <Mounting flange> As shown in Figures 1, 2 and 4, the mounting flange 24 is integrally provided at the distal end portion 232 of each branch pipe 23. The mounting flange 24 extends in a direction in which the distal end portions 232 of the two branch pipes 23 are aligned. The mounting flange 24 has a plate shape extending in the up-down direction and the left-right direction. By fixing this mounting flange 24 to an outer wall of an internal combustion engine (not shown), each branch pipe 23 of the intake manifold 10 is connected to a respective intake port of the internal combustion engine.

[0016] <Gas introduction portion> As shown in Figures 2 and 4 to 6, the gas introduction portion 25 has a structure that allows part of exhaust gas from an internal combustion engine (so-called EGR gas) to pass through the inside thereof. The gas introduction portion 25 is for introducing EGR gas into an air flowing portion inside the intake manifold 10 (the surge tank 21 in the present embodiment). In the present embodiment, EGR gas corresponds to an introduction gas other than air.

[0017] The gas introduction portion 25 is integrally provided on the surge tank 21 and each branch pipe 23 in a mode connecting the outer wall of the surge tank 21 and the outer wall of each branch pipe 23. As shown in Figures 2 and 4, hereinafter, the space sandwiched between the surge tank 21 and the plurality of branch pipes 23 is referred to as "space S". Further, in "space S", a portion on the connection side between the branch pipe 23 and the surge tank 21 in the extending direction of each branch pipe 23 (the right portion in Figure 2) is referred to as "portion P". Specifically, the gas introduction portion 25 is provided in a mode that closes the portion P on the connection side between the branch pipe 23 and the surge tank 21 in the extending direction of each branch pipe 23 in the space S without any gap.

[0018] As shown in Figures 2 and 4 to 6, the gas introduction portion 25 includes a chamber portion 31, a gas introduction path 32, and a gas discharge path 33. <Chamber portion> The chamber portion 31 constitutes an expansion chamber into which EGR gas flows among portions through which EGR gas passes. The chamber portion 31 is provided above the surge tank 21 in a manner adjacent to the surge tank 21. The chamber portion 31 is provided at a position sandwiched between the surge tank 21 and a portion on the distal end 232 side of each branch pipe 23. In the present embodiment, the chamber portion 31 is provided in such a manner that it closes a portion P (the right portion in FIG. 2) on the connection portion side between each branch pipe 23 and the surge tank 21 in the space S without any gap.

[0019] In the present embodiment, the chamber portion 31 and the surge tank 21 have the following structure. The intake manifold 10 has a base space portion 40. The interior of the base space portion 40 constitutes a volume chamber to which a plurality of branch pipes 23 are connected. A partition wall 41 that divides the volume chamber into two chambers is provided inside the base space portion 40. The partition wall 41 has a plate shape extending in the left-right direction and the front-rear direction. The partition wall 41 divides the volume chamber in the vertical direction into a first portion to which the plurality of branch pipes 23 are connected and a second portion to which the plurality of branch pipes 23 are not connected. In the present embodiment, the first portion serves as the surge tank 21, and the second portion serves as the chamber portion 31. In the present embodiment, a part of the outer surface of the surge tank 21 (specifically, the upper surface of the partition wall 41) also serves as a part of the inner surface of the chamber portion 31.

[0020] Further, the partition wall 41 has the following structure. As shown in FIG. 5, a first divided wall 121 that constitutes a rear side portion of the partition wall 41 is protrudingly provided on the inner surface of the second member 12. As shown in FIG. 6, a second divided wall 131 that constitutes a front side portion of the partition wall 41 is protrudingly provided on the inner surface of the third member 13. As shown in FIG. 4 to FIG. 6, when manufacturing the intake manifold 10, in a case where the second member 12 and the third member 13 are fixed to each other, protruding ends of the first divided wall 121 and the second divided wall 131 are joined to each other by vibration welding. In this way, the partition wall 41 composed of the first divided wall 121 and the second divided wall 131 is integrally formed.

[0021] <Gas introduction route> As shown in Figures 2 and 6, the gas introduction passage 32 is an introduction passage for introducing EGR gas from outside the intake manifold 10 into the chamber section 31. The gas introduction passage 32 is provided on the left wall of the chamber section 31 (hereinafter referred to as the left wall 31L) so as to protrude outward in a cylindrical shape. One end of the air introduction section 22 is open on the inner surface of the left wall 31L of the chamber section 31. The other end of the air introduction section 22 is a fixing section 321 to which the upstream portion of the EGR gas flow direction in the EGR passage (specifically, the EGR pipe) is fixed.

[0022] <Gas discharge channel> As shown in Figures 4 and 6, the gas discharge passage 33 is a discharge passage for releasing EGR gas from inside the chamber section 31 into the surge tank 21. The gas discharge passage 33 is formed by a through-hole provided in the partition wall 41. The gas discharge passage 33 extends vertically in a manner that connects the inside of the surge tank 21 and the inside of the chamber section 31. Two gas discharge passages 33 are provided in the partition wall 41, spaced apart in the left-right direction. One gas discharge passage 33 is provided above the connection portion of each of the two branch pipes 23 to the surge tank 21. By arranging the two gas discharge passages 33 in this way, the EGR gas released from the chamber section 31 to the surge tank 21 via each gas discharge passage 33 is distributed evenly to the two branch pipes 23.

[0023] <Reinforcement Ribs> As shown in Figures 2 and 4, the intake manifold 10 is provided with reinforcing ribs 50. The reinforcing ribs 50 protrude from the outer wall of the mounting flange 24, the outer wall of the branch pipe 23, and the outer wall of the gas inlet section 25. The reinforcing ribs 50 are plate-shaped and extend in the front-rear and up-down directions. The reinforcing ribs 50 extend from the mounting flange 24 through the tip of the branch pipe 23 to the gas inlet section 25. One reinforcing rib 50 is provided for each of the two branch pipes 23.

[0024] In the intake manifold 10 of this embodiment, the regulated air through the operation of the throttle mechanism is introduced into the surge tank 21 via the air inlet 22. EGR gas is also introduced into the surge tank 21 via the gas inlet 25. The air and EGR gas introduced into the surge tank 21 are then distributed and supplied to each intake port of the internal combustion engine via each branch pipe 23.

[0025] <Effects and Effects> The following describes the effects and benefits of the intake manifold 10 of this embodiment. (1) The intake manifold 10 comprises a surge tank 21, a plurality of branch pipes 23, and a gas inlet 25. The gas inlet 25 is provided integrally with the surge tank 21 and each branch pipe 23 in such a manner that it connects the outer wall of the surge tank 21 and the outer wall of each branch pipe 23.

[0026] According to this embodiment, the structure of the intake manifold 10 can be configured such that the surge tank 21 and the branch pipe 23 support each other via the gas introduction section 25. Therefore, the rigidity of the intake manifold 10 can be increased compared to one without such a gas introduction section 25. This suppresses vibrations of the intake manifold 10, thereby improving the NVH performance of the intake manifold 10, and consequently improving the NVH performance of the vehicle in which the intake manifold 10 is installed.

[0027] (2) The gas introduction section 25 is provided in such a manner that it completely seals the portion P of the space S sandwiched between the surge tank 21 and the multiple branch pipes 23, on the side of the connection portion between each branch pipe 23 and the surge tank 21 in the extending direction of each branch pipe 23. According to this embodiment, each branch pipe 23, the surge tank 21 and the gas introduction section 25 can be integrated without any gaps in the above portion P of space S. Therefore, the rigidity of the intake manifold 10 can be suitably increased.

[0028] (3) The intake manifold 10 is provided with reinforcing ribs 50. The reinforcing ribs 50 protrude from the outer wall of the mounting flange 24, the outer wall of the branch pipe 23, and the outer wall of the gas inlet section 25. The reinforcing ribs 50 extend from the mounting flange 24 through the tip of the branch pipe 23 to the gas inlet section 25.

[0029] According to this embodiment, the tip portion of the branch pipe 23 and the gas introduction portion 25 can be integrated via the reinforcing rib 50. This increases the overall rigidity of the intake manifold 10, including the tip portion of the branch pipe 23. Furthermore, the rigidity of the tip portion of the branch pipe 23, that is, the portion to which vibrations from the internal combustion engine are transmitted because it is connected to the intake port of the internal combustion engine, can be increased. This effectively improves the NV performance of the intake manifold 10.

[0030] (4) The gas introduction section 25 has a chamber section 31. According to this embodiment, the outer wall of the surge tank 21 and the outer wall of the branch pipe 23 can be integrated in such a way that they are connected via the chamber section 31.

[0031] (5) The intake manifold 10 has a base space 40 which constitutes a volume chamber to which a plurality of branch pipes 23 are connected. A partition wall 41 is provided inside the base space 40. The partition wall 41 divides the volume chamber into a surge tank 21 which is a first part to which the plurality of branch pipes 23 are connected, and a chamber 31 which is a second part to which the plurality of branch pipes 23 are not connected.

[0032] According to this embodiment, a relatively large volume chamber is formed inside the intake manifold 10, and this volume chamber is divided into two sections, one of which can be used as a surge tank 21 and the other as a chamber section 31. In this way, the surge tank 21 and the chamber section 31 can be partitioned inside the intake manifold 10 with a simple structure in which a single volume chamber is divided by a partition wall 41.

[0033] Furthermore, the opposing portions of the outer wall of the base space 40 are supported by each other via the partition wall 41. Therefore, although the intake manifold 10 is provided with a base space 40 that constitutes a volume chamber, the deformation of the outer wall of the base space 40 can be suppressed by the partition wall 41. This makes it possible to increase the rigidity of the intake manifold 10.

[0034] (6) The partition wall 41 has a gas discharge passage 33 consisting of a through hole that connects the inside of the surge tank 21 and the inside of the chamber section 31. According to this embodiment, a gas discharge passage 33 for releasing EGR gas from the inside of the chamber section 31 to the inside of the surge tank 21 can be provided with a simple structure such as forming a through hole in the partition wall 41.

[0035] <Example of changes> The above embodiment can be implemented with the following modifications. The above embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0036] The sensor passage section 26 and the pressure sensor 27 can be omitted. • The reinforcing rib 50 can be omitted. Instead of using a chamber section 31 as a component that integrally connects the outer walls of each branch pipe 23 and the outer wall of the surge tank 21, other components of the gas introduction section 25 (for example, the gas introduction passage 32) can be used. In short, it is sufficient to use a part of the gas introduction section 25 to integrally connect the outer walls of each branch pipe 23 and the outer wall of the surge tank 21.

[0037] As shown in Figure 7, a communication hole (hereinafter referred to as a gas discharge passage 63) that connects the inside of the branch pipe 23 and the inside of the chamber section 31 may be provided in the partition wall 60 that separates each branch pipe 23 from the chamber section 31. Specifically, the partition wall 60 is the part corresponding to the front wall of the branch pipe 23 and the part corresponding to the rear wall 21R of the surge tank 21. In the example shown in Figure 7, one gas discharge passage 63 is provided in each of the two branch pipes 23 at a position corresponding to the partition wall 60. With the above configuration, a gas discharge passage 63 for discharging EGR gas from the inside of the chamber section 31 to the inside of the branch pipe 23 can be arranged with a simple structure such as forming a communication hole in the partition wall 60 that separates each branch pipe 23 from the chamber section 31.

[0038] If the intake manifold has a partition wall separating the chamber section 31 and the air inlet section 22, a communication hole may be provided in this partition wall as a gas discharge passage that connects the inside of the chamber section 31 and the inside of the air inlet section 22. With this configuration, a gas discharge passage for releasing EGR gas from the inside of the chamber section 31 to the inside of the air inlet section 22 can be provided with a simple structure, such as forming a communication hole in the partition wall separating the chamber section 31 and the air inlet section 22.

[0039] The gas discharge passages 33 and 63 are not limited to being constructed by through-holes formed in the partition wall 41 or the bulkhead section 60, but may also be constructed by pipe members such as resin pipes or rubber pipes. For example, a pipe member can be provided to connect the outer wall of the air inlet section 22 and the outer wall of the chamber section 31 as a gas discharge passage. In addition, a pipe member can be provided to connect the outer wall of the surge tank 21 and the outer wall of the chamber section 31 as a gas discharge passage, or a pipe member can be provided to connect the outer wall of each branch pipe 23 and the outer wall of the chamber section 31.

[0040] The gas introduction section 25 may be provided in a manner that partially forms a gap in the space S between the surge tank 21 and the multiple branch pipes 23, in the portion P on the side of the extension direction of each branch pipe 23 where the branch pipe 23 connects to the surge tank 21.

[0041] As a gas inlet, a system can be adopted to introduce combustion gases (so-called blow-by gases) that have leaked from the combustion chamber of the internal combustion engine into the crankcase into the airflow portion inside the intake manifold 10. In this configuration, the blow-by gas corresponds to the introduced gas. Alternatively, a system can be adopted to introduce evaporated fuel (so-called purge gases) from the fuel tank of the internal combustion engine into the airflow portion inside the intake manifold 10. In this configuration, the purge gas corresponds to the introduced gas.

[0042] The intake manifold according to the above embodiment can also be applied to intake manifolds having three or more branch pipes. [Explanation of Symbols]

[0043] S Space P part 10 Intake Manifold 11 First component 12 Second Member 121 First dividing wall 13 Third Member 131 Second dividing wall 21 Surge Tank 21R rear wall 22 Air intake passage 221 Fixed part 22R rear wall 23 Branch pipe 231 Proximal end 24 Mounting flange 25 Gas inlet 26 Sensor passage section 27 Pressure Sensor 31 Chamber Section 31L left wall 32 Gas Inlet Path 321 Fixed part 33 Gas discharge channel 40 Base space 41 partition wall 50 Reinforcement Ribs 60 Next door 63 ガスLet the way out

Claims

1. In an intake manifold comprising a surge tank and a plurality of branch pipes, each individually connected to the surge tank and distributing the air inside the surge tank, The intake manifold has a gas introduction section that has a structure through which an introduced gas other than air passes, and introduces the introduced gas into the part of the intake manifold where air flows. When the three mutually orthogonal directions are defined as the up-and-down direction, the front-and-back direction, and the left-and-right direction, The branch pipe extends from the lower rear to the upper front of the surge tank, curving in a convex shape toward the rear. The base end and tip end of the aforementioned branch pipe are arranged with a gap between them in the vertical direction, with each opening forward. The base end is open on the inner surface of the rear wall of the surge tank. The gas introduction section is provided integrally with the surge tank and the branch pipe in such a manner that it connects the inner wall of the curved outer wall of the branch pipe with the opposing wall of the outer wall of the surge tank that is opposite to the inner wall, and has a chamber section that constitutes an expansion chamber into which the introduced gas flows. The chamber section is provided above the surge tank, adjacent to the surge tank. The intake manifold has a base space portion that constitutes a volume chamber to which the plurality of branch pipes are connected, and a partition wall provided inside the base space portion that divides the volume chamber into a surge tank portion to which the plurality of branch pipes are connected and a chamber portion to which the plurality of branch pipes are not connected. The partition wall is plate-shaped and extends in the left-right and front-back directions, dividing the volume chamber vertically into the surge tank and the chamber section, and has through holes extending vertically in a manner that connects the inside of the surge tank and the inside of the chamber section. Multiple through-holes are provided in the partition wall at intervals in the left-right direction, with one provided above each of the multiple branch pipes at a position above the connection portion with the surge tank. The interior of the chamber section is in communication with the interior of the surge tank through the plurality of through holes, but is not in direct communication with the interior of the plurality of branch pipes. Intake manifold.

2. The gas introduction section is provided in such a manner that it completely seals the space between the surge tank and the plurality of branch pipes, specifically the portion of the space on the side of the branch pipes in the direction of extension of the branch pipes where they connect to the surge tank. The intake manifold according to claim 1.

3. The branch pipe and the gas inlet have reinforcing ribs that protrude from the outer wall and extend from the tip of the branch pipe to the gas inlet. The intake manifold according to claim 2.

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