JP2016094852A - EGR mixing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower turbulence of EGR in an annular space of an annular chamber to suppress lowering of an introduction amount of EGR into an intake flow passage.SOLUTION: The annular chamber 7 is provided in an outer periphery of the intake flow passage 4 to partition the annular space 8 communicated to an EGR flow passage on an inner side. An annular slit 9 communicates the annular space 8 to the intake flow passage 4 to cause EGR to flow into the intake flow passage 4 from the annular space 8. An inflow regulation part 10 is provided in a part of the annular slit 9 to partially block the annular slit 9.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an EGR mixing structure in which a part of exhaust gas from an internal combustion engine is introduced into an intake passage of the internal combustion engine as EGR.

  Patent Document 1 describes an EGR mixing apparatus in which an EGR pipe is connected to an annular chamber, and the inside of the annular chamber and the inside of the intake pipe are communicated by an annular slit.

JP 2007-92592 A

  In the EGR mixing device of Patent Document 1, EGR can uniformly flow from the entire outer periphery of the intake pipe into the intake pipe through the annular slit. For this reason, for example, if the EGR pipe is bent and the flow of EGR in the EGR pipe before flowing into the annular chamber is disturbed, the EGR is further disturbed inside the annular chamber (annular space), and the inside of the intake pipe ( There is a possibility that the amount of EGR introduced into the intake air flow path will decrease.

  Therefore, an object of the present invention is to provide an EGR mixing device that can reduce disturbance of EGR in the annular space of the annular chamber and suppress a decrease in the amount of EGR introduced into the intake passage.

  In order to achieve the above object, the present invention provides an EGR mixing structure in which a part of exhaust gas from an internal combustion engine is introduced as EGR into an intake flow path of the internal combustion engine via an EGR flow path, and includes an annular chamber, an annular slit, and an inflow And a regulation unit.

  The annular chamber is provided on the outer periphery of the intake passage, and defines an annular space communicating with the EGR passage. The annular slit communicates the annular space and the intake passage, and allows EGR to flow from the annular space into the intake passage. The inflow restricting portion is provided in a part of the annular slit, narrows the slit width of the annular slit, or partially closes the annular slit.

  In the above configuration, in the region where the inflow restricting portion is provided in the annular space, the EGR that has flowed into the annular space easily flows along the annular space. For this reason, disturbance of EGR in the annular space can be reduced, and a decrease in the amount of EGR introduced into the intake flow path can be suppressed.

  Further, the EGR mixing structure may include a rectifying plate that is provided in the vicinity of the annular space in the EGR flow path and extends along the flow direction of the EGR.

  In the above configuration, the disturbance of EGR immediately before flowing into the annular space is suppressed by the rectifying plate. Therefore, the disturbance of EGR in the annular space is further suppressed, and the decrease in the amount of EGR introduced into the intake passage is suppressed. be able to.

  According to the present invention, it is possible to reduce the disturbance of EGR in the annular space of the annular chamber, and to suppress a decrease in the amount of EGR introduced into the intake passage.

It is a front view of the inlet cover concerning one embodiment of the present invention. It is the top view which looked at the inlet cover of FIG. 1 from the arrow II direction. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is IV-IV sectional drawing of FIG. It is VV sectional drawing of FIG. It is VI-VI sectional drawing of FIG. It is VII-VII sectional drawing of FIG. It is sectional drawing which shows a modification.

  Hereinafter, the inlet cover 1 which concerns on one Embodiment of this invention is demonstrated with reference to FIGS. As shown in FIGS. 1 and 2, the inlet cover 1 is formed by combining an inlet cover inner 2 and an inlet cover outer 3, and is a vehicle that employs EGR (Exhaust Gas Recirculation). It is fixed to the engine (internal combustion engine) 40. The inlet cover 1 includes an intake passage 4 (see FIGS. 5 and 7), an EGR passage 5 (see FIGS. 3, 4, and 7), and an EGR junction 6 (see FIGS. 3, 5, and 7). The EGR junction 6 is provided with an annular chamber 7, an annular space 8, an annular slit 9, and an inflow restricting portion 10 as shown in FIG. 5, and the EGR flow path 5 is provided with an as shown in FIG. A current plate 11 is provided.

  As shown in FIG. 2, the inlet cover inner 2 integrally includes an intake manifold portion 12, an inner intake pipe portion 13, an inner annular chamber forming portion 14, and an inner EGR flow path forming portion 15. It is fixed to the head 41. The intake manifold section 12 forms a cylinder communication space 16 (see FIG. 7) communicating with each cylinder (not shown) of the engine 40 between the cylinder head 41. The cylinder communication space 16 functions as a so-called intake manifold. The inlet cover outer 3 integrally includes an outer intake pipe portion 17, an outer annular chamber forming portion 18, and an outer EGR flow path forming portion 19.

  As shown in FIGS. 5 and 7, an inner intake passage 20 that is a downstream region of the intake passage 4 is formed in the inner intake pipe portion 13, and the downstream end of the inner intake passage 20 is the cylinder communication space 16. Communicate with. An outer intake passage 21 that is an upstream region of the intake passage 4 is formed in the outer intake pipe portion 17, and a flange that opens at the upstream end of the outer intake passage 21 is formed at the upstream end of the outer intake passage portion 17. A shaped intake pipe connecting portion 22 is formed. An intake pipe (not shown) is connected to the intake pipe connection portion 22 so that outside air (fresh air) flows into the intake flow path 4 from the intake pipe.

  The outer intake passage 21 is reduced in diameter toward the downstream side, and the EGR merging portion 6 is provided in a venturi portion in the vicinity of the communication portion between the inner intake passage 20 and the outer intake passage 21. The annular chamber 7 includes an inner annular chamber forming portion 14 on the outer periphery of the inner intake passage 20 and an outer annular chamber forming portion 18 on the outer periphery of the outer intake passage 21. The inner annular chamber forming portion 14 is formed with an annular groove-shaped inner annular space forming groove 23, and the outer annular chamber forming portion 18 is formed with an annular groove-shaped outer annular space forming groove 24. By the inner annular space forming groove 23 and the outer annular space forming groove 24, an annular annular space 8 is formed inside the annular chamber 7 on the outer periphery of the ventilation channel 4. The inner peripheral edge of the inner annular space forming groove 23 is defined by an annular inner slit forming rib 25, and the inner peripheral edge of the outer annular space forming groove 24 is defined by an annular outer slit forming rib 26. . The front end surface of the inner slit forming rib 25 and the front end surface of the outer slit forming rib 26 are separated from each other, and the annular space 8 and the intake passage 4 are communicated between the inner slit forming rib 25 and the outer slit forming rib 26. An annular slit 9 is formed.

  As shown in FIGS. 3 and 4, the EGR downstream channel 27, which is the downstream region of the EGR channel 5, is linearly formed by the inner EGR channel forming part 15 and the outer EGR channel forming part 19. The downstream end of the EGR downstream channel 27 communicates with the annular space 8. As shown in FIG. 4, the EGR upstream channel 28, which is the upstream region of the EGR channel 5, is formed in the outer EGR channel forming part 19, and its downstream end is at the upstream end of the EGR downstream channel 27. Communicate. The EGR flow path 5 bends at a substantially right angle at the EGR upstream flow path 28 and further bends at a substantially right angle between the EGR upstream flow path 28 and the EGR downstream flow path 27. The outer EGR flow path forming portion 19 is formed with a flange-shaped EGR pipe connection portion 29 in which the upstream end of the EGR upstream flow path 28 opens. An EGR pipe (not shown) is connected to the EGR pipe connection portion 29, and a part of the exhaust of the engine 40 flows from the EGR pipe to the EGR flow path 5 as EGR. The EGR that has flowed into the EGR flow path 5 flows through the annular slit 9 from the outer periphery of the intake flow path 4 in the EGR merging portion 6 and is mixed into the outside air flowing into the cylinder communication space 16 from the intake flow path 4.

  The inflow restricting portion 10 is provided in a part of the annular slit 9 and partially closes the annular slit 9. The inflow restricting portion 10 is a part of a circular arc shape in the entire circumferential area of the outer slit forming rib 26, and is formed to have a protruding height higher than that of the other areas and is in contact with the inner slit forming rib 25. The inflow restricting portion 10 is arranged on the side (high flow rate side) where the flow of EGR flowing from the EGR downstream side flow path 27 is fast in the entire circumferential area of the annular space 8. In this embodiment, EGR flows into the EGR downstream channel 27 from above (see FIG. 4), and in the EGR downstream channel 27, the lower side (see FIG. 3) flows faster than the upper side. In order to flow into the annular space 8, the inflow restricting portion 10 is disposed in the lower region of the annular space 8 (slit 9) (see FIG. 3).

  As shown in FIG. 3, the EGR downstream flow path 27 is provided with a flat plate-like rectifying plate 11 that extends linearly to the vicinity of the annular space 8 along the EGR flow direction. As shown in FIG. 6, the rectifying plate 11 includes an inner rectifying plate forming rib 30 protruding from the inner EGR flow path forming portion 15 and an outer rectifying plate forming rib 31 protruding from the outer EGR flow path forming portion 19. The

  According to the present embodiment, in the region where the inflow restricting portion 10 is provided in the annular space 8, after EGR does not flow directly into the intake flow path 4, but flows along the annular space 8 until reaching the annular slit 9. Then, it flows into the intake passage 4 from the annular slit 9. As described above, since the EGR that has flowed into the annular space 8 easily forms a flow along the annular space 8, the disturbance of the EGR in the annular space 8 can be reduced, and the introduction of the EGR into the intake passage 4 can be reduced. A decrease in the amount can be suppressed.

  Further, since the disturbance of EGR immediately before flowing into the annular space 8 is suppressed by the rectifying plate 11, the disturbance of EGR in the annular space 8 is further suppressed, and the amount of introduction of EGR into the intake passage 4 is reduced. Can be suppressed.

  As mentioned above, although the embodiment to which the invention made by the present inventor is applied has been described, the present invention is not limited by the discussion and the drawings that form part of the disclosure of the present invention according to this embodiment. That is, it is needless to say that other embodiments, examples, operation techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

  For example, in the above embodiment, the inflow restricting portion 10 that partially closes the annular slit 9 is provided, but instead of this, as shown in FIG. 8, the slit width (the inner slit forming rib 25 and the outer slit) of the annular slit 9 is provided. You may provide the inflow control part 32 which narrows a clearance gap between the formation ribs 26 rather than another part. In this case, the protruding height of a part of the outer slit forming rib 26 may be set to a height that is higher than the other regions and does not contact the inner slit forming rib 25.

  The present invention is widely applicable to internal combustion engines that employ EGR.

DESCRIPTION OF SYMBOLS 1 Inlet cover 2 Inlet cover inner 3 Inlet cover outer 4 Intake flow path 5 EGR flow path 6 EGR merge part 7 Annular chamber 8 Annular space 9 Annular slits 10, 32 Inflow restricting part 11 Rectifier plate 40 Engine (internal combustion engine)

Claims (2)

An EGR mixing structure for introducing a part of the exhaust gas of the internal combustion engine as EGR into the intake flow path of the internal combustion engine via the EGR flow path,
An annular chamber provided on an outer periphery of the intake flow path and defining an annular space communicating with the EGR flow path;
An annular slit that communicates the annular space and the intake passage, and allows EGR to flow into the intake passage from the annular space;
An EGR mixing structure, comprising: an inflow restricting portion that is provided in a part of the annular slit and narrows the slit width of the annular slit than other parts or partially closes the annular slit. The EGR mixed structure according to claim 1,
An EGR mixing structure comprising: a rectifying plate provided in the vicinity of the annular space in the EGR flow path and extending along a flow direction of EGR.

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