JP4516772B2 - Exhaust gas introduction device in internal combustion engine - Google Patents

Description

  The present invention relates to an exhaust gas introduction device for an internal combustion engine, in which a part of exhaust gas discharged from the internal combustion engine is introduced into the intake passage to the internal combustion engine and mixed with the intake air in the intake passage. It is about.

  In recent internal combustion engines, in order to clean the exhaust gas discharged from the internal combustion engine, a part of the exhaust gas is introduced (recirculated) into the intake passage. At the time of introduction into the passage, it is necessary to mix the exhaust gas introduced into the intake passage so that the exhaust gas flowing in the intake passage is uniformly dispersed at various places.

  Therefore, in Patent Document 1 as a prior art, a throttle valve is provided in a portion upstream of an exhaust gas introduction port for introducing exhaust gas from an exhaust system into the intake passage of the intake passage to the internal combustion engine, An intake swirling means is provided, and when the throttle valve is closed to the intake air flowing in the intake passage, a swirl flow is imparted by the throttle valve and the intake swirling means to thereby mix exhaust gas. It is described.

Further, in Patent Document 2 as another prior art, in an intake passage to an internal combustion engine, a portion upstream or downstream of an exhaust gas introduction port for introducing exhaust gas from an exhaust system into the intake passage. In addition, it is described that mixing of exhaust gas and intake air is achieved by providing a protruding piece inward from the inner surface of the intake passage and stirring the intake air with the protruding piece.
Japanese Patent Laid-Open No. 11-351071 Japanese Patent Laid-Open No. 09-209847

  However, the former can be applied to the case where exhaust gas is introduced (recirculated) over a wide operating range because the operating range in which the swirling flow is applied to the intake air is limited to the region where the throttle valve is closed. In addition, the intake swirl means provided on the inner surface of the intake passage for applying a swirl flow to the intake air with the throttle valve in a closed state with respect to the throttle valve Therefore, there is a problem that the flow resistance of the intake air is large.

  On the other hand, the latter can be applied when exhaust gas is introduced (refluxed) over a wide operating range, but in order to promote mixing of exhaust gas with respect to intake air, it is directed inward from the inner surface of the intake passage. The number of projecting pieces must be increased or the inward projecting height must be increased, so that the projecting pieces greatly impede the flow of intake air, and the flow resistance of the intake air There was a problem that it increased further than in the case of.

  The present invention aims to solve this problem and to provide an exhaust gas introduction device that can reliably promote exhaust gas mixing without increasing intake flow resistance. is there.

In order to achieve this technical problem, claim 1 of the present invention provides:
"In an exhaust gas introduction device comprising an exhaust gas introduction port for introducing exhaust gas from the internal combustion engine in an intake passage that guides intake air from an air cleaner to an intake manifold of the internal combustion engine,
A curved pipe is provided in a portion upstream of the exhaust gas inlet in the intake passage, and a plane including the axis of the inlet pipe and the axis of the outlet pipe in the bent pipe on the inner surface of the bent pipe; A protruding portion configured to extend in the axial direction of the outlet pipe portion is formed on one of the parallel inner left and right inner surfaces, and a protruding dimension from the one inner surface of the protruding portion is an intersection of the two axis lines. Intake air flowing along the one inner side surface from the inlet pipe portion , which is provided so as to be the highest in the portion corresponding to or in the vicinity thereof and gradually lower toward the downstream side along the axis of the outlet pipe portion by channeling the direction of the center by the raised portion, and the intake air flowing through the outlet tube portion and configured to pivot about the axis of the outlet pipe portion. "
It is characterized by that.

Next, claim 2 of the present invention provides
“In the description of claim 1, the exhaust gas inlet is provided in a region closer to the inlet pipe than the center of the outlet pipe as viewed from the axial direction of the outlet pipe in the bent pipe.”
It is characterized by that.

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And claim 3 of the present invention provides
“In the description of claim 1 or 2 , the outlet pipe portion of the bent pipe is connected to the downstream intake pipe downstream of the bent pipe in the intake passage, and the axis of the outlet pipe portion is When viewed from the axial direction of the inlet pipe portion in the bent pipe, the flange joint is joined with a plurality of bolts while being inclined in the direction of the raised portion side with respect to the axial line in the downstream intake pipe. At least one of the bolts is disposed on an outer portion of the raised portion when viewed from the axial direction of the downstream intake pipe, and further, the raised portion of the outer peripheral surface of the bent pipe A recess is provided in an outer portion of the one bolt so as to extend in the axial direction of the single bolt.
It is characterized by that.

  Among the intake air flowing into the bent pipe from the inlet pipe portion, a part of the intake air flowing along one inner side surface is drifted toward the center by the raised portion provided on the one inner side surface. The entire intake air, including a portion of the intake air that drifts in the direction of the air flow, is changed in direction from the axis of the inlet pipe to the axis of the outlet pipe in the bent pipe. As a result, the twist of turning around the axis of the outlet pipe is applied, so that the entire intake air is swirled and exits from the outlet pipe.

In other words, the bent pipe having the above-described configuration can impart a swirling flow to the entire intake air flowing in the outlet pipe portion of the bent pipe. Therefore, the bent pipe is connected to the exhaust gas introduction port in the intake passage to the internal combustion engine. By providing it at the upstream side , the exhaust gas from the exhaust gas inlet can be quickly mixed with the swirling intake air.

Further, the swirl flow is imparted to the intake air by changing the direction from the axis of the inlet pipe to the axis of the outlet pipe in the bent pipe, and the raised portion provided in the bent pipe so as to extend in the direction of the outlet pipe. The flow resistance of the intake air can be made much lower than in the case of both prior arts described above, and the application of the swirling flow can be ensured over a wide operating range of the internal combustion engine, As a result, the mixability of the exhaust gas with respect to the intake air can be ensured over a wide operating range of the internal combustion engine.
In particular, as described in claim 1, the protruding portion is the highest in the portion corresponding to the intersection of the two axes or the vicinity thereof in the protruding portion from the one inner surface, and the outlet pipe portion. In this ridge, the portion on the outlet pipe portion side acts so as to attenuate the swirling flow of the intake air by the ridge. This can be reduced and the swirl flow of the intake air can be further strengthened, so that the above-described effect can be promoted.

  By the way, in the bent pipe, on the inner surface of the bent pipe, the inlet pipe is formed on one inner side surface of both the left and right inner side faces parallel to a plane including the axis of the inlet pipe and the axis of the outlet pipe in the bent pipe. The swirl flow imparted to the intake air flows out from the outlet pipe portion of the bent pipe by providing the raised portion that is configured to drift the intake air flowing along the one inner surface from the portion toward the center. In addition to the momentum becoming strongest, an intake flow that flows in the direction of the outlet pipe along the radially inner surface of the bend is also generated inside the bend pipe.

  Therefore, as described in the second aspect, the bent pipe is provided in a portion upstream of the exhaust gas inlet in the intake passage, and the exhaust gas inlet is provided on the outlet pipe portion of the bent pipe. By providing in the region closer to the inlet pipe part than the center of the outlet pipe part when viewed from the axial direction, the outlet gas part from the outlet pipe part in the bent pipe with respect to the part where the exhaust gas inlet port opens in the intake passage. Since the swirl flow of the intake air can be exerted in a state where the momentum is strong, the intake air flow flowing in the direction of the outlet pipe portion along the inner surface in the radial direction of the bend can be added and exerted. In addition to the above-described effects, it is possible to reliably reduce the deposit and deposition of carbon deposits or the like in the exhaust gas at the portion where the exhaust gas introduction port opens in the intake passage.

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In addition, as described in claim 3 , the outlet pipe portion of the bent pipe is connected to the downstream side intake pipe downstream of the bent pipe in the intake passage, and the axis of the outlet pipe portion is In the case of flange joining with a plurality of bolts in a state of being inclined in the direction of the raised portion side with respect to the axis line of the downstream side intake pipe line as seen from the axial direction of the inlet pipe portion in the bent pipe, the flange At least one bolt of the joining bolts is disposed at an outer portion of the raised portion when viewed from the axial direction of the downstream intake pipe, and further, the raised portion of the outer peripheral surface of the bent pipe A tool for turning the one bolt from the recess to the one piece by providing a recess in the outer part of the portion so as to extend in the axial direction of the one bolt. of Since it is possible to load the bolt, it is possible to bring the single bolt closer to the center by using the raised portion that becomes the pivot point of the swirl flow in the bent pipe. The joint can be made smaller and lighter.

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

  1 to 4 show a first embodiment.

  In this figure, reference numeral 1 denotes an intake passage for guiding intake air from an air cleaner (not shown) to an intake manifold (not shown) in the internal combustion engine. The intake passage 1 is connected to an upstream side intake passage 2 from the air cleaner. The downstream intake passage 3 to the intake manifold and the bent pipe 4 connecting the intake passage 3 to the intake manifold 3 are configured.

  An exhaust gas introduction port 6 to which an exhaust gas recirculation passage 5 from an exhaust system in an internal combustion engine is connected to the downstream side intake passage 3 at a portion adjacent to the bent pipe 4 (near portion). An exhaust gas recirculation control valve 7 is provided so as to open in the passage 3 and controls the amount of exhaust gas introduced by opening and closing the exhaust gas inlet 6 according to a load or the like in the internal combustion engine. Is provided.

  The bent pipe 4 is connected to the upstream side intake passage 2 by an inlet pipe portion 8 that is joined by flange joining in which a flange portion 9 is fastened by a plurality of bolts (not shown), and the downstream side intake passage 3. On the other hand, an outlet pipe portion 10 is provided that is joined by flange joining in which the flange portion 11 is fastened by a plurality of bolts (not shown).

  And, on the inner surface of the bent tube 4, one inner surface of the left and right inner surfaces 4a, 4b parallel to the plane including the axis 8a of the inlet tube 8 and the axis 10a of the outlet tube 10 in the bent tube 4. 4a is provided with a raised portion 12 at the intersection of the axis 8a of the inlet pipe 8 and the axis 10a of the outlet pipe 10 or in the vicinity of the intersection, and the intake air flowing from the inlet pipe 8 is Among them, the intake air flowing along the one inner side surface 4 a is configured to drift in the center direction at the raised portion 12.

  The raised portion 12 is configured by partially denting a part of the side plate constituting the bent tube 4. That is, the recessed part 13 is provided in the outer peripheral surface of the bending pipe 4 in the part outside the said protruding part 12. As shown in FIG.

Moreover, the raised portion 12 extends in the direction of the axis 10 a of the outlet pipe portion 10, and the protruding dimension from the inner side surface 4 a is the start end portion of the raised portion 12, that is, the inlet pipe portion 8. The portion corresponding to the intersection of the axis 8a and the axis 10a of the outlet pipe portion 10 or the highest in the vicinity thereof , and gradually decreases from this portion toward the downstream side along the axis 10a of the outlet pipe portion 10, And it is comprised so that the said exit pipe part 10 may become zero in the location joined to the said downstream side intake passage 3. As shown in FIG.

  In addition, as shown in FIGS. 3 and 4, the exhaust gas inlet 6 is viewed from the direction of the axis 10 a of the outlet pipe portion 10 in the bent pipe 4 in the inner surface of the downstream side intake passage 3. And provided at a portion corresponding to the axis 8 a of the inlet pipe portion 8.

  In this configuration, the intake air from the air cleaner reaches the intake manifold in the internal combustion engine through the upstream intake passage 2, the bent pipe 4 and the downstream intake passage 3.

  When the intake air flows through the bent pipe 4, a part of the intake air flowing into the bent pipe 4 from the inlet pipe portion 8 along the one inner surface 4a flows into the one inner surface 4a. As shown by the dotted arrow A in FIG. 4, the entire intake air including a part of the intake air that drifts in this way is caused to flow into the bent pipe 4 by the raised portion 12 provided in the bent pipe 4. By changing the direction from the axis 8a of the portion 8 to the direction of the axis 10a of the outlet pipe portion 10, a portion of the intake air flows in the direction of the intake air as indicated by the dotted arrow A as described above. Since the twist of swirling around the axis 10a of the tube portion 10 is given, the whole of the intake air becomes a swirl flow as shown by a solid arrow B in FIGS. Out from the portion 9 into the downstream intake passage 3 That.

Accordingly, since the intake air flowing into the downstream intake passage 3 from the bent pipe 4 is swirling as shown by the solid arrow B, it is introduced into the downstream intake passage 3 from the exhaust gas inlet 6. The exhaust gas thus produced can be quickly mixed with the swirling intake air.

In this case, the protruding portion 12 in the bent pipe 4 has the highest projecting dimension from the inner surface of the protruding portion 12 in the portion corresponding to the intersection of the two axes 8a and 10a or in the vicinity thereof . By being configured to gradually decrease from this portion toward the downstream side of the flow along the axis 10a of the outlet pipe portion 10, the portion on the outlet pipe portion 10 side of the raised portion 12 is Since it is possible to reduce the effect of attenuating the swirling flow of the intake air by the portion 12, it is possible to further strengthen the swirling flow of the intake air.

  In addition, the exhaust gas inlet 6 has the inner surface of the downstream side intake passage 3 as shown in FIGS. 3 and 4 when viewed from the direction of the axis 10a of the outlet pipe portion 10 in the bent pipe 4. An area closer to the inlet pipe 8 than the center 10a ′ of the outlet pipe 10, that is, through a center 10a ′ of the outlet pipe 10 and an orthogonal line 10a ″ perpendicular to the axis 8a of the inlet pipe 8 It is provided in a region on the inlet pipe 8 side.

  By providing the raised portion 12 in the bent tube 4, the swirling flow is caused to flow into the bent pipe 4 as indicated by a solid arrow B in FIGS. In addition to being able to be applied, the inside of the bent tube 4 is arranged in the direction of the outlet pipe part 10 along the inner surface 4c on the radially inner side of the bent, as shown by the two-dot chain line arrow C in FIG. The intake airflow that flows through can also be generated at the same time.

  Therefore, as described above, the bent pipe 4 is provided on the upstream side of the downstream intake passage 3, while the exhaust gas inlet 6 in the downstream intake passage 3 is connected to the axis of the outlet pipe portion 10 in the bent pipe 4. When viewed from the direction of 10 a, the exhaust gas inlet 6 is provided in the region closer to the inlet pipe 8 than the center 10 a ′ of the outlet pipe 10, so that the exhaust gas inlet 6 opens into the downstream intake passage 3. The swirling flow indicated by the solid arrow B can be exerted in a strong state, and the intake flow indicated by the two-dot chain line arrow C can also be added.

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  Next, FIGS. 5 to 7 show a second embodiment.

  In the second embodiment, on the premise of the first embodiment, the axis 10a of the outlet pipe portion 10 in the bent pipe 4 connecting the upstream intake passage 2 and the downstream intake passage 3 is provided. When viewed from the direction of the axis 8a of the inlet pipe 8 in the bent pipe 4, as shown in FIG. 6, an appropriate angle θ in the direction of the ridge 12 with respect to the axis 3a in the downstream intake pipe 3 This is a case where only a tilt is adopted.

  In the second embodiment, at least one bolt among a plurality of bolts 11 a, 11 b, 11 c for flange-joining the outlet pipe portion 10 in the bent pipe 4 to the downstream side intake passage 3. 11a as viewed in the direction of the axis 3a of the downstream side intake pipe 3, as shown in FIG. 7, is disposed on the outer portion of the raised portion 12, and further, out of the outer peripheral surface of the bent pipe 4 As shown in FIGS. 6 and 7, the recess 13 in the outer portion of the raised portion 12 is configured to extend in the direction of the axis 11a ′ of the single bolt 11a.

  According to the second embodiment, the outlet pipe portion 10 in the bent pipe 4 is connected to the downstream side intake pipe 3, and the axis 10 a of the outlet pipe portion 10 is connected to the inlet pipe portion in the bent pipe 4. As seen from the direction of the axial line 8a, the flanges are joined by a plurality of bolts 11a, 11b, and 11c in a state of being inclined in the direction of the raised portion 12 with respect to the axial line 3a in the downstream intake pipe 3. In this case, a tool 14 such as a wrench for turning the one bolt 11a can be loaded from the recess 13 to the one bolt 11a as shown by a two-dot chain line in FIG. As a result, the one bolt 11a can be brought closer to the center by using the raised portion 12 that becomes the pivot point of the swirl flow on the bent tube 4 and the flange 11 can be A it can be reduced.

It is a vertical front view which shows 1st Embodiment in this invention. FIG. 2 is a sectional view taken along line II-II in FIG. 1. FIG. 3 is a sectional view taken along line III-III in FIG. 1. FIG. 4 is a sectional view taken along line IV-IV in FIG. 1. It is a vertical front view which shows 2nd Embodiment in this invention. FIG. 6 is a sectional view taken along line VI-VI in FIG. 5. FIG. 7 is a bottom view taken along the line VII-VII in FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Intake passage 2 Upstream side intake passage 3 Downstream side intake passage 4 Curved pipe 4a, 4b Both right and left inner surfaces 4b in a curved pipe 4c Radial inner surface in a curved pipe 5 Exhaust gas recirculation path 6 Exhaust gas introduction port 8 Entrance in a curved pipe Pipe part 8a Axis of inlet pipe part 10 Outlet pipe part in bent pipe 10a Axis line of outlet pipe part 10a 'Center of outlet pipe part 9, 11 Flange part 11a, 11b, 11c Bolt 12 Raised part 13 Recessed part

Claims (3)

In an exhaust gas introducing device configured to open an exhaust gas introduction port for introducing exhaust gas from the internal combustion engine into an intake passage that guides intake air from an air cleaner to an intake manifold of the internal combustion engine.
A curved pipe is provided in a portion upstream of the exhaust gas inlet in the intake passage, and a plane including the axis of the inlet pipe and the axis of the outlet pipe in the bent pipe on the inner surface of the bent pipe; A protruding portion configured to extend in the axial direction of the outlet pipe portion is formed on one of the parallel inner left and right inner surfaces, and a protruding dimension from the one inner surface of the protruding portion is an intersection of the two axis lines. Intake air flowing along the one inner side surface from the inlet pipe portion , which is provided so as to be the highest in the portion corresponding to or in the vicinity thereof and gradually lower toward the downstream side along the axis of the outlet pipe portion by channeling the direction of the center by the raised portion, the exhaust gas in an internal combustion engine, characterized in that the intake air flowing through the outlet tube portion and configured to pivot about the axis of the outlet pipe portion It is introduced equipment. In the description of claim 1, the exhaust gas inlet is provided in a region closer to the inlet pipe than the center of the outlet pipe when viewed from the axial direction of the outlet pipe in the bent pipe. An exhaust gas introducing device for an internal combustion engine.   3. The outlet pipe portion of the bent pipe according to claim 1, wherein the outlet pipe portion of the bent pipe is connected to the downstream side intake pipe line downstream of the bent pipe in the intake passage, and the axis of the outlet pipe portion is the bent portion. The flange is joined with a plurality of bolts while being inclined in the direction of the raised portion with respect to the axis of the downstream intake pipe as seen from the axial direction of the inlet pipe in the pipe. At least one bolt of the bolts is disposed at an outer portion of the raised portion when viewed from the axial direction of the downstream intake pipe, and further, of the raised portion of the outer peripheral surface of the bent pipe. An exhaust gas introducing device for an internal combustion engine, wherein a recess is provided in an outer portion so as to extend in an axial direction of the one bolt.

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