JP6232093B2 - Gas reflux device - Google Patents

Description

  The present invention relates to a gas recirculation device that supplies exhaust gas to an intake system.

  A gas recirculation device has been proposed in which a part of exhaust gas is supplied to an intake system by connecting an exhaust system and an intake system of the engine (see Patent Document 1). Thus, by mixing the exhaust gas with the intake air toward the combustion chamber, the combustion temperature can be lowered to improve the exhaust gas purification performance, and the pump loss can be reduced to improve the fuel efficiency performance. .

Japanese Utility Model Publication No. 3-114563

  By the way, in order to achieve further improvement in the fuel efficiency performance and exhaust gas purification performance of the engine, it is necessary to evenly distribute the exhaust gas to each intake port of the engine. That is, in the gas recirculation device, it is required to mix the intake air and the exhaust gas well.

  An object of the present invention is to mix intake air and exhaust gas well.

A gas recirculation device according to the present invention is provided in an intake system of an engine, and includes a throttle body having a throttle valve and a valve shaft that supports the throttle valve, an intake system of the engine, and intake air is supplied to each intake port of the engine. An intake manifold that distributes; an adapter member that is provided between the throttle body and the intake manifold and that guides intake air from the throttle body to the intake manifold; and an intake system and an exhaust system of the engine A gas supply path that guides part of the exhaust gas from the exhaust system to the intake system, and the adapter member includes an introduction port to which the gas supply path is connected, and the valve shaft intersects the virtual plane including the center line and a matching or parallel to the center line of the through passage, the opening to the through channel A discharge port provided on the first connecting passage connecting the first discharge port and the introduction port, a first expansion chamber in which the first discharge port is opened, intersects the virtual plane, the first release A second discharge port facing the port and opening in the through flow channel; and a second connection flow channel connecting the introduction port and the second discharge port; And an extension room.

  According to the present invention, the adapter member provided between the throttle body and the intake manifold is provided in the first connection flow path that connects the introduction port and the first discharge port, and the first discharge port opens. An expansion chamber, and a second expansion chamber provided in a second connection flow path connecting the introduction port and the second discharge port, and opening the second discharge port. As a result, the exhaust gas can be gradually released from the first discharge port and the second discharge port, and the intake air and the exhaust gas can be mixed well.

It is the schematic which shows the engine provided with the gas recirculation apparatus which is one embodiment of this invention. It is sectional drawing which shows an intake system along the AA line of FIG. It is a perspective view which shows an EGR adapter. (A) is a front view which shows an EGR adapter from the arrow A direction of FIG. 3, (b) is a side view which shows an EGR adapter, (c) is a rear view which shows an EGR adapter, (d) is It is a bottom view which shows an EGR adapter. (A) is sectional drawing which shows the positional relationship of a throttle body and an EGR adapter, (b) is explanatory drawing which shows the flow condition of intake air using an arrow. It is a perspective view which shows the EGR adapter divided | segmented along the AA line of Fig.4 (a). (A) And (b) is sectional drawing which shows a part of intake system with which the gas recirculation apparatus which is other embodiment of this invention is provided. It is explanatory drawing which shows the opening area of an introduction port and a discharge | release port. It is sectional drawing of the EGR adapter which shows the flow condition of EGR gas using an arrow. It is explanatory drawing which shows the structure of the connection flow path of an EGR adapter. It is sectional drawing which shows the gas recirculation apparatus as a comparative example. It is a comparison figure which compares and shows the EGR variation rate of an Example and a comparative example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view showing an engine 11 provided with a gas recirculation device 10 according to an embodiment of the present invention. The illustrated engine 11 is a horizontally opposed engine, but is not limited to this, and may be an inline engine, a V-type engine, or the like.

  As shown in FIG. 1, the engine 11 includes a cylinder block 13 including a plurality of cylinder bores 12 and a cylinder head 14 attached to the cylinder block 13. In the cylinder head 14, a plurality of intake ports 16 connected to the intake system 15 are formed, and a plurality of exhaust ports (not shown) connected to the exhaust system 17 are formed. The intake system 15 has an intake passage 22 including an intake duct 18, a throttle body 19, an EGR adapter (adapter member) 20, an intake manifold 21 and the like. The exhaust system 17 has an exhaust passage 24 constituted by an exhaust pipe 23, an exhaust manifold (not shown), and the like. The intake air flowing through the intake passage 22 is distributed to the intake ports 16 through the intake manifold 21 after the flow rate is adjusted through the throttle body 19 and is supplied from the intake port 16 to a combustion chamber (not shown). The exhaust gas discharged from the combustion chamber is supplied from an exhaust port (not shown) to the exhaust passage 24 and is discharged to the outside through a catalytic converter and a silencer (not shown).

  In order to improve the fuel consumption performance and exhaust gas purification performance of the engine 11, the engine 11 is provided with an exhaust gas recirculation system 30 that recirculates a part of the exhaust gas to the intake system 15. The exhaust gas recirculation system 30 has an EGR supply path (gas supply path) 33 constituted by supply pipes 31 and 32. A supply pipe 31 constituting the upstream side of the EGR supply path 33 is connected to the exhaust pipe 23 of the exhaust system 17, and a supply pipe 32 constituting the downstream side of the EGR supply path 33 is connected to the EGR adapter 20 of the intake system 15. It is connected to the. An EGR valve 34 that controls the flow rate of EGR gas is provided between the supply pipe 31 and the supply pipe 32. By configuring the exhaust gas recirculation system 30 in this way, a part of the exhaust gas is supplied as EGR gas to the intake system 15 via the EGR supply path 33 and the EGR adapter 20, and the supply amount of EGR gas is as follows. It is controlled by the EGR valve 34. The EGR is “Exhaust Gas Recirculation”.

  FIG. 2 is a cross-sectional view showing the intake system 15 along the line AA in FIG. As shown in FIGS. 1 and 2, the throttle body 19 provided in the intake system 15 has a disk-like throttle valve 40 and a valve shaft 41 that supports the throttle valve 40. By driving the valve shaft 41 by a throttle motor (not shown), the throttle valve 40 can be rotated in the opening direction and the closing direction, and the intake passage 42 in the throttle body 19 can be opened and closed. The illustrated throttle body 19 is a so-called butterfly-type throttle body, and has a structure in which the throttle valve 40 rotates around a central valve shaft 41. Therefore, as shown by an arrow α in FIG. 2, when opening the throttle valve 40, the upper end (first end) 43 of the throttle valve 40 moves in a direction away from the EGR adapter 20, The lower end (second end) 44 moves in a direction approaching the EGR adapter 20.

  FIG. 3 is a perspective view showing the EGR adapter 20. As shown in FIGS. 1 to 3, the EGR adapter 20 provided on the downstream side of the throttle body 19 includes an intake passage (through passage) 50 that guides intake air from the throttle body 19 to the intake manifold 21. . Further, the EGR adapter 20 includes an introduction port Pi to which the EGR supply path 33 is connected, discharge ports Po1 and Po2 that open to the intake flow path 50, and a connection flow path that allows the introduction port Pi and the discharge ports Po1 and Po2 to communicate with each other. C1 and C2. Thus, by configuring the EGR adapter 20, the EGR gas supplied from the EGR supply path 33 to the introduction port Pi is discharged to the intake flow path 50 via the connection flow paths C1 and C2 and the discharge ports Po1 and Po2. The The EGR gas discharged from the discharge ports Po1 and Po2 to the intake flow path 50 is distributed to the intake ports 16 through the intake manifold 21 together with the intake air. Note that FIG. 2, which is a cross-sectional view, shows one discharge port Po1 of the discharge ports Po1 and Po2, and one connection flow path C1 of the connection flow paths C1 and C2.

[Structure of EGR adapter]
Next, the structure of the EGR adapter 20 that discharges EGR gas to the intake system 15 will be described. 4A is a front view showing the EGR adapter 20 from the direction of arrow A in FIG. 3, and FIG. 4B is a side view showing the EGR adapter 20. FIG. 4C is a rear view showing the EGR adapter 20, and FIG. 4D is a bottom view showing the EGR adapter 20.

  As shown in FIGS. 3 and 4, the EGR adapter 20 has an adapter body 52 having a substantially rectangular parallelepiped shape in which bolt holes 51 are formed at four corners. An attachment surface 53 attached to the intake manifold 21 is formed at one end in the thickness direction of the adapter main body 52, and an attachment surface 54 attached to the throttle body 19 is formed at the other end in the thickness direction of the adapter main body 52. ing. The adapter main body 52 is formed with an intake passage 50 penetrating from one end to the other end in the thickness direction. Further, a first discharge port Po <b> 1 and a second discharge port Po <b> 2 that are opposed to each other are formed on the flow path wall 55 that divides the intake flow path 50 in the adapter main body 52. That is, a pair of discharge ports Po1 and Po2 that open to the intake flow path 50 are formed on the flow path wall 55 that surrounds and partitions the intake flow path 50. Further, the discharge ports Po1 and Po2 are formed at positions that intersect a virtual plane X described later.

  An introduction port Pi to which the supply pipe 32 of the EGR supply path 33 is connected is formed in the lower part 56 of the adapter main body 52. Further, a first connection channel C1 that connects the introduction port Pi and the discharge port Po1 is formed from the lower portion 56 to the side portion 57 of the adapter main body 52, and a first connection channel C1 that connects the introduction port Pi and the discharge port Po2 is formed. A two-connection channel C2 is formed. As shown to Fig.4 (a), 1st aperture | diaphragm | squeeze part Ca1 whose flow path cross-sectional area is smaller than the other site | part of the connection flow path C1 is formed in the 1st connection flow path C1. In the first connection channel C1, a first expansion chamber Cb1 is formed on the downstream side of the first throttle portion Ca1. A discharge port Po1 is opened in the first expansion chamber Cb1, and the first expansion chamber Cb1 and the intake passage 50 are adjacent to each other. Similarly, a second throttle portion Ca2 having a smaller channel cross-sectional area than other portions of the connection channel C2 is formed in the second connection channel C2. Further, in the second connection channel C2, a second expansion chamber Cb2 is formed on the downstream side of the second throttle portion Ca2. A discharge port Po2 is opened in the second expansion chamber Cb2, and the second expansion chamber Cb2 and the intake passage 50 are adjacent to each other.

[Basic structure of discharge port]
Next, the basic structure of the discharge ports Po1 and Po2 that discharge EGR gas will be described. FIG. 5A is a cross-sectional view showing the positional relationship between the throttle body 19 and the EGR adapter 20, and FIG. 5B is an explanatory view showing the flow state of intake air using arrows. 5A and 5B show the same part as the part shown in FIG. FIG. 6 is a perspective view showing the EGR adapter 20 divided along the line AA in FIG. FIG. 6 shows the positional relationship between the EGR adapter 20 and the virtual plane X. In the present specification, the structure of one discharge port Po1 will be mainly described, but the other discharge port Po2 has the same structure. For this reason, the description of the structure of the other discharge port Po2 is omitted.

  As shown in FIG. 5A, the discharge port Po1 formed on the side portion 57 of the adapter main body 52 is formed at a position that intersects the virtual plane X. Here, as shown in FIGS. 5A and 6, the virtual plane X is a plane that includes the center line CL <b> 1 of the valve shaft 41 and extends in the penetrating direction of the intake passage 50. In other words, the virtual plane X is a plane that includes the center line CL1 of the valve shaft 41 and coincides with or is parallel to the center line CL2 of the intake passage 50. In other words, the virtual plane X is a plane that includes the center line CL1 of the valve shaft 41 and extends along the flow direction of the intake air. In this way, by forming the discharge port Po1 at a position intersecting the virtual plane X, the intake air and the EGR gas can be mixed well as will be described later.

  As described above, the valve shaft 41 extending in the width direction is fixed at the center of the throttle valve 40, and the throttle valve 40 rotates around the valve shaft 41 when the intake passage 42 is opened and closed. Therefore, when the throttle valve 40 is opened, the intake passage 42 is opened largely in the vicinity of the upper end portion 43 and the lower end portion 44 of the throttle valve 40, while the intake passage portion is in the vicinity of the side end portion 45 of the throttle valve 40. 42 is opened small. That is, when the throttle valve 40 is opened, the flow rate of the intake air greatly increases in the vicinity of the upper end portion 43 and the lower end portion 44 of the throttle valve 40, while the intake air in the vicinity of the side end portion 45 of the throttle valve 40. The flow rate increases slightly.

  As described above, since the intake air hardly flows in the vicinity of the side end 45 of the throttle valve 40 as compared with the vicinity of the upper end 43 and the lower end 44, the intake air is sucked in comparison with the vicinity of the upper end 43 and the lower end 44. Air flow tends to decrease. Therefore, as indicated by an arrow in FIG. 5B, the intake air that has passed through the vicinity of the upper end portion 43 of the throttle valve 40 is drawn downward so as to be twisted, while the lower end portion 44 of the throttle valve 40 is drawn. It is assumed that the intake air that has passed in the vicinity of is drawn upward so as to be twisted. Thus, the space extending downstream from the side end portion 45 of the throttle valve 40, that is, the virtual plane X and the space in the vicinity thereof, is a space where turbulent flow is likely to occur because the intake air intersects.

  Therefore, the EGR adapter 20 has a discharge port Po1 that discharges EGR gas at a position that intersects the virtual plane X. Thereby, since the EGR gas can be supplied to the turbulent intake air, the intake air and the EGR gas can be positively mixed using the turbulent flow of the intake air. Thereby, variation in the proportion of EGR gas contained in the intake air (hereinafter referred to as EGR content rate) can be suppressed, and EGR gas can be supplied to each intake port 16 almost equally. .

[Opening position of discharge port]
Next, the opening position of the discharge port Po1 that discharges EGR gas will be described in more detail. As shown in FIG. 5A, the discharge port Po1 is formed close to the upper end portion 43 side of the throttle valve 40, that is, upward. That is, when the discharge port Po1 is partitioned into the first opening o1 and the second opening o2 with the virtual plane X as a boundary, the upper first opening o1 is formed wider than the lower second opening o2. The Thus, the intake air and the EGR gas are mixed well as described later by making the opening area of the first opening o1 wider than the second opening o2, that is, bringing the discharge port Po1 upward. Can do.

  As shown in FIG. 5B, the distance D1 from the upper end 43 of the throttle valve 40 to the EGR adapter 20 is longer than the distance D2 from the lower end 44 to the EGR adapter 20. Therefore, the intake air passing through the vicinity of the upper end portion 43 of the throttle valve 40 and moving downward is more upstream than the intake air passing through the vicinity of the lower end portion 44 of the throttle valve 40 and moving upward. To reach the center line CL2 of the intake flow path 50 and the virtual plane X. In other words, it is assumed that the intake air 50 of the EGR adapter 20 tends to collect intake air at the upper part rather than the lower part. Therefore, in the EGR adapter 20, a large amount of EGR gas is released to the upper part of the intake flow path 50 where intake air tends to gather by moving the discharge port Po <b> 1 upward. Thereby, the variation in the EGR content rate in the intake air can be suppressed, and the EGR gas can be supplied to each intake port 16 almost equally.

  In the above description, the discharge port Po1 of the EGR adapter 20 is formed so as to be moved upward. However, the present invention is not limited to this, and the discharge port of the EGR adapter may be formed so as to be moved downward. Here, FIGS. 7A and 7B are cross-sectional views showing a part of the intake system 15 provided in the gas recirculation device 60 according to another embodiment of the present invention. FIG. 7A shows the positional relationship between the EGR adapter 61 and the throttle body 62, and FIG. 7B shows the flow state of the intake air using arrows. 7 (a) and 7 (b), parts and members similar to the parts and members shown in FIGS. 5 (a) and 5 (b) are given the same reference numerals and description thereof is omitted. FIG. 7 shows one discharge port Po3 of the pair of discharge ports, as in FIG.

As shown in FIG. 7A, the intake system 15 of the engine 11 is provided with an intake manifold 21, an EGR adapter 61, and a throttle body 62. 7A, when the throttle valve 63 provided in the throttle body 19 is opened, the lower end portion (first end portion) 64 of the throttle valve 63 moves away from the EGR adapter 61. Then, the upper end portion (second end portion) 65 of the throttle valve 63 moves in a direction approaching the EGR adapter 61 . Further, as shown in FIG. 7A, the discharge port Po3 of the EGR adapter 61 is formed close to the lower end portion 64 side of the throttle valve 63 , that is, downward. That is, when the discharge port Po3 is divided into the first opening o1 and the second opening o2 with the virtual plane X as a boundary, the lower first opening o1 is formed wider than the upper second opening o2. The As described above, by bringing the discharge port Po3 downward, the intake air and the EGR gas can be mixed well as in the case of the EGR adapter 20 described above.

  That is, as shown in FIG. 7B, the distance D3 from the lower end 64 of the throttle valve 63 to the EGR adapter 61 is longer than the distance D4 from the upper end 65 to the EGR adapter 61. For this reason, the intake air passing through the vicinity of the lower end portion 64 of the throttle valve 63 and moving upward is more upstream than the intake air passing through the vicinity of the upper end portion 65 of the throttle valve 63 and moving downward. To reach the center line CL2 of the intake flow path 50 and the virtual plane X. Thus, in the intake passage 50 of the EGR adapter 61, it is assumed that the intake air is likely to collect in the lower part than in the upper part. Therefore, in the EGR adapter 61, the discharge port Po3 for releasing EGR gas is moved downward. Formed. As a result, a large amount of EGR gas can be released to the lower part of the intake passage 50 where intake air is likely to collect, and variations in the EGR content rate in the intake air can be suppressed.

[Opening area of discharge port]
Next, the opening area of the discharge port Po1 that discharges EGR gas will be described. FIG. 8 is an explanatory diagram showing opening areas of the introduction port Pi and the discharge port Po1. FIG. 9 is a cross-sectional view of the EGR adapter 20 showing the flow of EGR gas using arrows. As indicated by hatching in FIG. 8, the opening area A1 of the discharge port Po1 is set wider than the opening area A2 of the introduction port Pi. Similarly, the opening area of the discharge port Po2 is also set wider than the opening area A2 of the introduction port Pi. As described above, by expanding the opening areas of the discharge ports Po1 and Po2, as shown by arrows in FIG. 9, the EGR gas can be dispersed and the flow velocity can be lowered, and the EGR gas can be gradually released from the discharge ports Po1 and Po2. Can be released. That is, the intake air layer flowing in the vicinity of the flow path wall 55 that is the inner peripheral surface of the intake flow path 50, that is, the intake air layer that is considered to generate a lot of turbulent flow, does not greatly collapse, Therefore, the intake air and the EGR gas can be actively mixed using the turbulent flow of the intake air. Thereby, the variation in the EGR content rate in the intake air can be suppressed, and the EGR gas can be supplied to each intake port 16 almost equally.

[Extended structure of connection flow path]
Subsequently, an extended structure of the connection flow paths C1 and C2 for guiding the EGR gas from the introduction port Pi to the discharge ports Po1 and Po2 will be described. Here, FIG. 10 is an explanatory view showing the structure of the connection channels C1 and C2 of the EGR adapter 20. FIG. As shown in FIG. 10, the adapter main body 52 of the EGR adapter 20 is formed with a pair of connection channels C <b> 1 and C <b> 2 from the lower part 56 to the side part 57. The introduction port Pi and the discharge port Po1 are connected via one connection flow path C1, and the introduction port Pi and the discharge port Po2 are connected via the other connection flow path C2. Further, a first expansion chamber Cb1 in which the discharge port Po1 is opened is formed in the first connection channel C1. The first expansion chamber Cb1 is partitioned on the downstream side of the first throttle portion Ca1, and the first expansion chamber Cb1 has a larger channel cross-sectional area than the first throttle portion Ca1. That is, as shown in FIG. 10, the first expansion chamber Cb1 has a flow path width W2 wider than the flow path width W1 of the first throttle portion Ca1. Similarly, a second expansion chamber Cb2 in which the discharge port Po2 is opened is formed in the second connection channel C2. The second expansion chamber Cb2 is partitioned on the downstream side of the second throttle portion Ca2, and the second expansion chamber Cb2 has a larger channel cross-sectional area than the second throttle portion Ca2.

  As described above, by providing the expansion chambers Cb1 and Cb2 in the connection flow paths C1 and C2, as shown by arrows in FIG. 9, the EGR gas can be dispersed and the flow velocity can be lowered, so that the discharge ports Po1 and Po2 EGR gas can be released slowly. As a result, the intake air layer that flows in the vicinity of the flow path wall 55 that is the inner peripheral surface of the intake flow path 50, that is, the intake air layer that is considered to generate a lot of turbulent flow, is not greatly collapsed. Since the gas can be supplied, the intake air and the EGR gas can be positively mixed using the turbulent flow of the intake air. Thereby, the variation in the EGR content rate in the intake air can be suppressed, and the EGR gas can be supplied to each intake port 16 almost equally. Moreover, by providing the expansion chambers Cb1 and Cb2 in the connection flow paths C1 and C2, the EGR gas and the intake air can be mixed in the expansion chambers Cb1 and Cb2. Thereby, mixing with intake air and EGR gas can be accelerated | stimulated, and the dispersion | variation in the EGR content rate in intake air can be suppressed.

[Connection channel restriction structure]
Subsequently, the throttle structure of the connection channels C1 and C2 for guiding the EGR gas from the introduction port Pi to the discharge ports Po1 and Po2 will be described. As described above, the adapter main body 52 of the EGR adapter 20 is formed with a pair of connection flow paths C1 and C2 from the lower portion 56 to the side portion 57. The introduction port Pi and the discharge port Po1 are connected via one connection flow path C1, and the introduction port Pi and the discharge port Po2 are connected via the other connection flow path C2. In the first connection channel C1, a first throttle portion Ca1 having a smaller channel cross-sectional area than other parts of the connection channel C1 is formed. That is, as shown in FIG. 10, the first throttle portion Ca1 has a channel width W1 narrower than the downstream channel width W2 and the upstream channel width W3. Similarly, a second throttle portion Ca2 having a smaller channel cross-sectional area than other portions of the connection channel C2 is formed in the second connection channel C2.

  As described above, by providing the throttle portions Ca1 and Ca2 in the connection flow paths C1 and C2, the flow rate of the EGR gas can be lowered when passing through the throttle portions Ca1 and Ca2. EGR gas can be released. Further, by providing the throttle portions Ca1 and Ca2 in the connection flow paths C1 and C2, pulsation of the EGR gas introduced from the exhaust system can be suppressed, so that the EGR gas is gently released from the discharge ports Po1 and Po2. be able to. As a result, the intake air layer that flows in the vicinity of the flow path wall 55 that is the inner peripheral surface of the intake flow path 50, that is, the intake air layer that is considered to generate a lot of turbulent flow, is not greatly collapsed. Since the gas can be supplied, the intake air and the EGR gas can be positively mixed using the turbulent flow of the intake air. Thereby, the variation in the EGR content rate in the intake air can be suppressed, and the EGR gas can be supplied to each intake port 16 almost equally.

[Comparative example]
Then, the effect of the gas recirculation apparatus 10 of an Example is demonstrated taking the gas recirculation apparatus 100 as a comparative example as an example. Here, FIG. 11 is a sectional view showing a gas reflux device 100 as a comparative example. FIG. 12 is a comparative view showing the EGR variation rate of the example and the comparative example in comparison. Note that the EGR variation rate shown in FIG. 12 is a difference between the EGR content rate of the entire intake air and the EGR content rate of the intake air supplied to each intake port 16. That is, as the EGR variation rate approaches “0”, the EGR content rate of the intake air supplied to each intake port 16 becomes equal, which means that the variation in the EGR content rate is suppressed.

  As shown in FIG. 11, the gas recirculation device 100 as a comparative example has an EGR adapter 101 provided between the intake manifold 21 and the throttle body 19. In the EGR adapter 101, an intake passage 102 for guiding intake air is formed, and an introduction port 103 to which the EGR supply passage 33 is connected is formed. In addition, the introduction port 103 is open to the intake passage 102, and the EGR gas that has flowed into the introduction port 103 is directly released to the intake passage 102. Thus, when the EGR gas is supplied directly from the introduction port 103 to the intake flow path 102, it is difficult to uniformly mix the intake air and the EGR gas. For this reason, as shown in FIG. 12, in the gas recirculation device 100 of the comparative example, there is a large difference in the EGR variation rate of each intake port 16. On the other hand, in the gas recirculation device 10 of the embodiment, as described above, since various devices are applied to the discharge ports Po1 and Po2 and the connection flow paths C1 and C2, the EGR variation rates of the intake ports 16 are mutually different. You can get closer.

It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. In the above description, the pair of discharge ports Po1 and Po2 are formed with respect to the EGR adapter 20. However, the present invention is not limited to this, and three or more discharge ports may be formed in the EGR adapter 20. One discharge port may be formed in the EGR adapter 20. In the above description, the discharge ports Po1 and Po2 are formed on the side portion 57 of the EGR adapter 20. However, the present invention is not limited to this, and the discharge ports Po1 and Po2 are connected to the upper part and the lower part 56 of the EGR adapter 20. It may be formed. In the above description, the introduction port Pi is formed in the lower portion 56 of the EGR adapter 20, but the present invention is not limited to this, and the introduction port Pi may be formed in the side portion 57 or the upper portion of the EGR adapter 20. It goes without saying that it is good. In the illustrated example, the virtual plane X coincides with the center line CL2 of the intake flow path 50. However, the present invention is not limited to this, and the virtual plane X is parallel to the center line CL2 of the intake flow path 50. May be.

DESCRIPTION OF SYMBOLS 10 Gas recirculation apparatus 11 Engine 15 Intake system 16 Intake port 17 Exhaust system 19 Throttle body 20 EGR adapter (adapter member)
21 Intake manifold 33 EGR supply path (gas supply path)
40 Throttle valve 41 Valve shaft 50 Intake flow path (through flow path)
60 Gas recirculation device 61 EGR adapter (adapter member)
62 Throttle body 63 Throttle valve Pi Inlet port Po1 First discharge port C1 First connection channel Ca1 First throttle Cb1 First expansion chamber Po2 Second discharge port C2 Second connection channel Ca2 Second throttle Cb2 Second expansion Room X Virtual plane CL1 Center line CL2 Center line

Claims (3)

A throttle body provided in an intake system of the engine, including a throttle valve and a valve shaft that supports the throttle valve;
An intake manifold that is provided in an intake system of the engine and distributes intake air to each intake port of the engine;
An adapter member provided between the throttle body and the intake manifold, and having a through flow path for guiding intake air from the throttle body to the intake manifold;
A gas supply path that is connected to an intake system and an exhaust system of the engine and guides part of exhaust gas from the exhaust system to the intake system;
Have
The adapter member is
An introduction port to which the gas supply path is connected;
A first discharge port that includes a center line of the valve shaft and intersects a virtual plane that is coincident with or parallel to the center line of the through-flow channel and opens into the through-flow channel;
A first expansion chamber provided in a first connection flow path connecting the introduction port and the first discharge port, the first discharge port opening;
A second discharge port that intersects the virtual plane, faces the first discharge port, and opens into the through flow path;
A second expansion chamber provided in a second connection flow path connecting the introduction port and the second discharge port, wherein the second discharge port opens;
A gas reflux device. In gas feedback device according to claim 1 Symbol placement,
The opening area of the first discharge port is larger than the opening area of the introduction port,
The gas reflux device, wherein an opening area of the second discharge port is wider than an opening area of the introduction port. The gas reflux device according to claim 1 or 2 ,
The adapter member is
A first throttle portion provided in the first connection channel upstream of the first expansion chamber, having a smaller channel cross-sectional area than other portions of the first connection channel;
A second throttle part provided in the second connection channel upstream of the second expansion chamber, having a smaller channel cross-sectional area than other portions of the second connection channel;
A gas reflux device.

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