JP2014129801A - Exhaust gas reflux device of vehicle engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust gas reflux device of a vehicle engine which can suppress the scattering of condensed water generated in an exhaust gas reflux passage in a cylinder head into a manifold.SOLUTION: An exhaust gas reflux passage 13 for refluxing an exhaust gas comprises an upstream-side passage 14 formed in an air cylinder row direction from an exhaust port 7 at the end of a cylinder head 2 in an air cylinder row cross direction, and gradually lowered at its bottom face 22 from the exhaust port 7 side, and a downstream-side passage 15 connected to the upstream-side passage 14 and oriented to the air cylinder row cross direction. The downstream-side passage 15 is cooled by cooling water in a cooling water inlet 12. A protruding wall 21 protruded toward a ceiling face 23 from the bottom face 22 of the upstream-side passage 14 and having a clearance between the ceiling face 23 and itself is formed at the side end of the exhaust port 7 of the upstream-side passage 14. Furthermore, the upper end of the protruding wall 21 is made longer than the cross section center O of the exhaust port 7. Furthermore. The upper end of the protruding wall 21 is made higher than the upper end of a connecting port 20 of the upstream-side passage 14 and the downstream-side passage 15.

Description

  The present invention relates to an exhaust gas recirculation device for a vehicle engine used in a vehicle, and is suitable for a case where an exhaust gas recirculation passage for recirculating a part of exhaust gas flowing through an exhaust port to an intake port or an intake manifold is formed in a cylinder head. Is.

  As an exhaust gas recirculation device for a vehicle engine in which the exhaust gas recirculation passage is formed in the cylinder head as described above, for example, there is one described in Patent Document 1 below. In this exhaust gas recirculation device for a vehicle engine, a concave groove continuous to the exhaust port is formed in one side of a cylinder head to which an exhaust manifold is attached in the cylinder row direction, that is, the crankshaft direction. A portion of the recessed groove opposite to the exhaust port is connected to a downstream portion of the exhaust gas recirculation passage formed in the cylinder head toward the other side of the cylinder head to which the intake manifold is attached. Then, the upper part of the exhaust gas recirculation passage is formed by covering the recessed groove with a cover plate provided integrally with the exhaust manifold. At that time, a portion covering the recessed groove of the cover plate is deformed so as to be away from one side surface of the cylinder head to form a bulging portion, and the bulging portion and the recessed groove constitute an upstream portion of the exhaust gas recirculation passage.

JP 2011-43096 A

  As in the exhaust gas recirculation device for a vehicle engine described in Patent Document 1, the exhaust gas recirculation passage is formed in the cylinder head by the cooling water in the cooling water passage in the cylinder head. The exhaust gas flowing through the inside is often cooled. Also in the exhaust gas recirculation device for a vehicle engine described in Patent Document 1, there is a cooling water passage in the vicinity of the downstream portion of the exhaust gas recirculation passage formed in the cylinder head, and the exhaust gas flowing in the downstream portion of the exhaust gas recirculation passage Is cooled by the cooling water in the cooling water passage. On the other hand, in the exhaust gas recirculation device for a vehicle engine described in Patent Document 1, the height of the upstream portion of the exhaust gas recirculation passage constituted by the recessed groove and the bulging portion increases as the distance from the exhaust port increases. It is low. As described above, when the exhaust gas in the downstream portion of the exhaust gas recirculation passage is cooled by the cooling water in the cooling water passage, condensed water in which the exhaust gas is condensed may be generated in the downstream portion of the exhaust gas recirculation passage. At this time, if the exhaust port side upstream of the exhaust gas recirculation passage is low, the condensed water generated in the downstream portion of the exhaust gas recirculation passage easily flows from the upstream portion of the exhaust gas recirculation passage to the exhaust port side. For example, when the driver depresses the accelerator pedal at once, the flow rate of the exhaust gas flowing from the cylinder to the exhaust port rapidly increases, and the condensate water in the upstream portion of the exhaust gas recirculation passage is pulled into the exhaust port by the negative pressure associated therewith. The condensed water drawn into the exhaust port flows to the exhaust manifold according to the flow rate of the exhaust gas, and further flows to the exhaust gas sensor disposed in the exhaust manifold. The exhaust gas sensor touches the condensed water, and the exhaust gas sensor There is a risk of cracking or performance degradation.

  The present invention has been made paying attention to the above-mentioned problems, and is a vehicle capable of suppressing the condensate generated in the exhaust gas recirculation passage in the cylinder head from being scattered in the exhaust manifold. It is an object of the present invention to provide an exhaust gas recirculation device for an engine.

  In order to solve the above-described problems, an embodiment of the present invention is an exhaust gas recirculation device for a vehicle engine having a plurality of cylinders, which is attached to one end of a cylinder head in a direction intersecting the cylinder row, An intake manifold connected to an intake port of a cylinder, an exhaust manifold attached to the other end of the cylinder head in a direction crossing the cylinder row, and connected to an exhaust port of each cylinder; and the exhaust manifold An exhaust gas sensor that is mounted and detects exhaust gas discharged from the exhaust port, and an exhaust gas recirculation that is formed in the cylinder head and recirculates part of the exhaust gas flowing through the exhaust port to the intake port or the intake manifold. A passage and the exhaust gas recirculation passage, and the front of the cylinder head on the other end side in the direction intersecting the cylinder row An upstream passage portion formed from the exhaust port in the cylinder row direction and having a bottom surface that becomes lower as the distance from the exhaust port side, and the exhaust gas recirculation passage are configured and connected to the upstream passage portion to form the cylinder Formed in a direction intersecting with the row and formed by a downstream passage portion cooled by cooling water in the cooling water passage, and an end portion on the exhaust port side of the upstream passage portion, from the bottom surface to the ceiling surface An exhaust gas recirculation device for a vehicle engine, comprising: a protruding wall that protrudes toward the ceiling and has a preset clearance with respect to the ceiling surface.

  Moreover, the upper end part of the said protrusion wall was set to the position higher than the cross-sectional center of the said exhaust port to which the said upstream channel | path part is connected.

  Moreover, the upper end part of the said protrusion wall was set to the position higher than the upper end part of the connection port of the said upstream channel | path part and the said downstream channel | path part.

  In addition, the upstream passage portion has a cross-sectional area that increases as the distance from the protruding wall increases.

  Further, when the protruding wall is a first protruding wall, a second protrusion that protrudes from the ceiling surface toward the bottom surface between the first protruding wall and the connection port of the upstream passage portion. A wall was formed, and a lower end portion of the second protruding wall was set at a position lower than an upper end portion of the first protruding wall.

  In addition, a concave curved surface is formed by denting the surface opposite to the exhaust port of at least one of the first projecting wall and the second projecting wall.

  Further, a recessed groove that is recessed downward is formed between the protruding wall and the connection port in the bottom surface of the upstream passage portion.

  Thus, according to the embodiment of the present invention, when the vehicle engine has a plurality of cylinders, one end of the intake manifold connected to the intake port of each cylinder in the direction intersecting the cylinder row of the cylinder head Install to. Further, an exhaust manifold connected to the exhaust port of each cylinder is attached to the other end in the direction intersecting with the cylinder row of the cylinder head. An exhaust gas sensor for detecting exhaust gas discharged from the exhaust port is attached to the exhaust manifold. An exhaust gas recirculation passage for recirculating a part of the exhaust gas flowing through the exhaust port to the intake port or the intake manifold is formed in the cylinder head. The exhaust gas recirculation passage is formed from the exhaust port toward the cylinder row direction on the other end side in the direction intersecting the cylinder row of the cylinder head, and becomes an upstream side passage portion that becomes lower as the bottom surface moves away from the exhaust port side. A downstream passage portion connected to the upstream passage portion, connected to the upstream passage portion and formed in a direction intersecting with the cylinder row, and cooled by the cooling water in the cooling water passage. And the protruding wall which protrudes toward the ceiling surface from the bottom face of an upstream channel | path part and has a preset clearance gap with respect to a ceiling surface is formed in the exhaust port side edge part of an upstream channel | path part. Therefore, the condensed water of the exhaust gas generated in the exhaust gas recirculation passage hardly flows to the exhaust port side in the upstream passage portion. Further, even if the condensed water flows to the exhaust port side in the upstream passage portion, it is possible to suppress the condensed water from being pulled into the exhaust port by the protruding wall, and therefore the condensed water is scattered in the exhaust manifold. Can be suppressed. As a result, the exhaust gas sensor attached to the exhaust manifold can be protected.

  Moreover, the upper end part of the protrusion wall was set to a position higher than the cross-sectional center of the exhaust port to which the upstream side passage part is connected. Thereby, even if condensed water is pulled in in an exhaust port by the flow of exhaust gas, condensed water can be made to adhere to the ceiling surface of an exhaust port. Thereby, the condensed water can be shifted from the main flow of the exhaust gas in the exhaust port, and the amount of condensed water riding on the flow of the exhaust gas can be reduced. Therefore, it is possible to prevent the condensed water from scattering into the exhaust manifold, and as a result, it is possible to protect the exhaust gas sensor attached to the exhaust manifold.

  Moreover, the upper end part of the protrusion wall was set in the position higher than the upper end part of the connection port of an upstream channel | path part and a downstream channel | path part. Thereby, even if the condensed water in the downstream passage portion flows into the upstream passage portion from the upper end portion of the connection port, the protruding wall can suppress the condensed water from being pulled into the exhaust port. Therefore, it is possible to prevent the condensed water from scattering into the exhaust manifold, and as a result, it is possible to protect the exhaust gas sensor attached to the exhaust manifold.

  Further, the upstream passage portion has a larger cross-sectional area as it is farther from the protruding wall. Thereby, even if condensed water accumulates in the upstream passage portion, the condensed water can be collected on the connection port side with the downstream passage portion. Since the condensed water accumulated on the connection port side has a long distance to the exhaust port, it is possible to suppress the condensed water from being pulled into the exhaust port. Therefore, it is possible to prevent the condensed water from scattering into the exhaust manifold, and as a result, it is possible to protect the exhaust gas sensor attached to the exhaust manifold.

  Further, when the protruding wall is a first protruding wall, a second protruding wall protruding from the ceiling surface toward the bottom surface is formed between the first protruding wall of the upstream passage portion and the connection port. The lower end of the second projecting wall is set at a position lower than the upper end of the first projecting wall. Thereby, it can be set as the labyrinth in an upstream channel | path part, and it can suppress that condensed water is pulled into an exhaust port from an upstream channel | path part. Therefore, it is possible to prevent the condensed water from scattering into the exhaust manifold, and as a result, it is possible to protect the exhaust gas sensor attached to the exhaust manifold.

  Further, a concave curved surface was formed by denting the surface opposite to the exhaust port of at least one of the first projecting wall and the second projecting wall. Thereby, the condensed water moving to the exhaust port side in the upstream side passage portion hits the concave curved surface and is returned in the reverse direction, that is, the downstream side passage portion direction, and the condensed water is pulled from the upstream side passage portion to the exhaust port. Can be suppressed. Therefore, it is possible to prevent the condensed water from scattering into the exhaust manifold, and as a result, it is possible to protect the exhaust gas sensor attached to the exhaust manifold.

  Further, a recessed groove recessed downward is formed between the projecting wall and the connection port in the bottom surface of the upstream passage portion. Thereby, condensed water accumulates in the concave groove, and it is possible to suppress the condensed water from being pulled into the exhaust port from the upstream side passage portion. Therefore, it is possible to prevent the condensed water from scattering into the exhaust manifold, and as a result, it is possible to protect the exhaust gas sensor attached to the exhaust manifold.

1 is a front view showing a first embodiment of a vehicle engine to which an exhaust gas recirculation device of the present invention is applied. It is a side view of the vehicle engine of FIG. It is a perspective view of the cylinder head of the vehicle engine of FIG. It is XX sectional drawing of FIG. FIG. 2 is an explanatory diagram of an exhaust gas flow in an exhaust gas recirculation passage of the vehicle engine of FIG. 1. FIG. 5 is an enlarged plan view of the vicinity of an upstream side passage portion of the exhaust gas recirculation passage in FIG. 4. FIG. 5 is a front view of an upstream passage portion of the exhaust gas recirculation passage of FIG. 4. FIG. 5 is a front view of an upstream side passage portion of an exhaust gas recirculation passage showing a second embodiment of the exhaust gas recirculation device for a vehicle engine of the present invention. It is a front view of the upstream passage part of the exhaust gas recirculation passage showing a third embodiment of the exhaust gas recirculation apparatus for a vehicle engine of the present invention.

  Next, a first embodiment of an exhaust gas recirculation device for a vehicle engine according to the present invention will be described with reference to the drawings. FIG. 1 is a front view of the vehicle engine of the present embodiment, and FIG. 2 is a side view of the vehicle engine of FIG. In the vehicle engine of this embodiment, a cylinder head 2 is attached to the upper end surface of the cylinder block 1, and a cylinder head cover 3 is attached to the upper end surface of the cylinder head 2. A crankcase 4 is formed in the lower part of the cylinder block 1, and a crankshaft 5 is rotatably accommodated in the crankcase 4. An oil pan (not shown) is attached to the lower end surface of the cylinder block 1. A transmission (not shown) is attached to the vehicle engine on the right side of FIG.

  A plurality of, in the present embodiment, three combustion chambers (not shown) are formed along the cylinder row on the joint surface of the cylinder head 2 with the cylinder block 1. Therefore, the axis of the crankshaft 5 is parallel to the arrangement direction of the combustion chambers, that is, the cylinder row. The engine body is mounted on the vehicle in various orientations, but is mounted so that the cylinder head 2 is positioned above the cylinder block 1, so that the direction is the engine upper side and the opposite direction is the engine lower side. Define.

  3 is a perspective view of a cylinder head of the vehicle engine shown in FIG. 1, and FIG. 4 is a sectional view taken along line XX of FIG. Each combustion chamber is connected to an intake port 6 for taking the air-fuel mixture into the combustion chamber and an exhaust port 7 for exhausting exhaust gas from the combustion chamber. In this embodiment, two intake ports 6 and two exhaust ports 7 are connected to each combustion chamber. The intake port on the combustion chamber side end of the intake port 6 is opened and closed by an unillustrated intake valve, and the exhaust port on the combustion chamber side end of the exhaust port 7 is opened and closed by an exhaust valve. In particular, since the combustion chamber and the exhaust port are at high temperatures, a cooling water passage called a water jacket is formed around them, and the cooling water is cooled by the cooling water flowing through the cooling water passage. The cooling water flows into the cooling water passage in the cylinder head 2 from the cooling water inlet 12.

  The intake ports 6 of all the cylinders are connected to an intake manifold 8, and the exhaust ports 7 of all the cylinders are connected to an exhaust manifold 9. The intake manifold 8 is attached to the lower end face of FIG. 4 in the cylinder head 2, that is, one end face in a direction crossing the cylinder row direction. Further, the exhaust manifold 9 is attached to the upper end face in FIG. 4 of the cylinder head 2, that is, the other end face in the direction intersecting the cylinder row direction. The intake manifold 8 is connected to an intake duct (not shown), and the exhaust manifold 9 is connected to an exhaust pipe 10 that includes a catalytic converter or the like. An exhaust gas sensor 19 that detects exhaust gas is attached to the exhaust pipe 10.

  Exhaust gas generated in the combustion chamber is discharged from the exhaust port 7 through the exhaust manifold 9 to the outside through the exhaust pipe 10. In the present embodiment, the cylinder head 2 is provided with an exhaust gas recirculation device that recirculates a part of the exhaust gas to the intake side. Reference numeral 11 in the figure is a control valve for controlling the recirculation of the exhaust gas, and is generally called an EGR valve. The inlet side of the EGR valve 11 is connected to the exhaust port 7, and the outlet side of the EGR valve 11 is connected to the intake manifold 8. Accordingly, when the EGR valve 11 is opened, a part of the exhaust gas is recirculated to the intake manifold 8. Further, when the EGR valve 11 is closed, a part of the exhaust gas is not recirculated to the intake side.

  Since the exhaust gas is hot, it is desirable to cool a part of the exhaust gas when returning it to the intake side. In the present embodiment, for example, a part of the exhaust gas in the exhaust port 7 on the right end side in FIG. 4 is supplied from the exhaust gas recirculation passage 13 to the EGR valve 11. The exhaust gas recirculation passage 13 includes an upstream passage portion 14 along the other end in the direction intersecting the cylinder row direction of the cylinder head 2 to which the exhaust manifold 9 is attached, and the upstream passage portion 14 to the cylinder. And a downstream passage portion 15 that is directed to one end portion in a direction that intersects the cylinder row direction of the head 2. The EGR valve 11 is connected to the downstream end of the downstream passage portion 15 of the exhaust gas recirculation passage 13.

  Of these, the downstream side passage portion 15 of the exhaust gas recirculation passage 13 has an outer peripheral surface located inside the cooling water inlet portion 12 as clearly shown in FIG. 3. Therefore, a part of the exhaust gas flowing in the downstream passage portion 15 of the exhaust gas recirculation passage 13 is cooled by, for example, cooling water flowing in the cooling water inlet portion 12, and is supplied from the EGR valve 11 to the intake manifold 8 after cooling. The On the other hand, the upstream side passage portion 14 of the exhaust gas recirculation passage 13 includes a concave groove portion 16 that opens to the other end surface in the direction intersecting the cylinder row direction of the cylinder head 2 to which the exhaust manifold 9 is attached. For example, as shown in FIG. 7, the concave groove portion 16 becomes lower as the bottom surface 22 moves away from the exhaust port 7 side. FIG. 5 is an explanatory view of the flow of exhaust gas in the exhaust gas recirculation passage 13, and FIG. 6 is an enlarged plan view around the upstream side passage portion of the exhaust gas recirculation passage of FIG. As clearly shown in FIG. 6, the upstream passage portion 14 is configured by covering the concave groove portion 16 with a lid member 18 for attaching the exhaust manifold 9 to the cylinder head 2 via the packing 17. The connecting portion between the upstream passage portion 14 and the downstream passage portion 15 is referred to as a connection port 20.

  FIG. 7 is a front view of the upstream side passage portion 14 of the exhaust gas recirculation passage 13 of FIG. In the present embodiment, the first projecting wall 21 is formed at the end of the upstream passage portion 14 on the exhaust port 7 side. The first protruding wall 21 protrudes from the bottom surface 22 of the upstream passage portion 14 toward the ceiling surface 23 and has a gap set in advance with respect to the ceiling surface 23. In the present embodiment, as described above, in the downstream side passage portion 15 of the exhaust gas recirculation passage 13, a part of the exhaust gas is cooled by the cooling water flowing in the cooling water inlet portion 12. Condensate may be generated in the interior.

  The white arrow of FIG. 7 has shown the flow of condensed water. For example, condensed water of exhaust gas generated in the downstream passage portion 15 flows in the upstream passage portion 14 toward the exhaust port 7. For example, when the driver depresses the accelerator pedal at once, the flow rate of the exhaust gas flowing from the cylinder to the exhaust port 7 rapidly increases, and the condensate water in the upstream side passage portion 14 of the exhaust gas recirculation passage 13 is exhausted by the negative pressure associated therewith. There is a possibility of being pulled into the port 7. The condensed water drawn into the exhaust port 7 flows into the exhaust pipe 10 through the exhaust manifold 9. An exhaust gas sensor 19 is attached to the exhaust pipe 10, and if condensed water adheres to the exhaust gas sensor 19, there is a risk that the exhaust gas sensor 19 will be cracked by water or the performance may be reduced.

  In the present embodiment, since the first projecting wall 21 is formed at the end of the upstream passage portion 14 on the exhaust port 7 side, the condensate is pulled into the exhaust port 7 due to the projecting wall 21 being in the way. The exhaust gas sensor 19 can be protected as a result. Moreover, in this embodiment, the upper end part of the 1st protrusion wall 21 was set to the position higher than the cross-sectional center O of the exhaust port 7 to which the upstream channel | path part 14 is connected. Even when the condensed water in the upstream passage portion 14 is pulled into the exhaust port 7 by the exhaust gas flow, the condensed water adheres to the ceiling surface of the exhaust port 7. Since the main flow of the exhaust gas in the exhaust port 7 is in the vicinity of the cross-sectional center O of the exhaust port 7, the attachment position of the condensed water deviates from the exhaust gas main flow, and the amount of condensed water riding on the exhaust gas flow can be reduced. .

  Further, the upper end portion of the first projecting wall 21 was set at a position higher than the upper end portion of the connection port 20 between the upstream side passage portion 14 and the downstream side passage portion 15. Therefore, it is possible to suppress the condensed water flowing into the upstream passage portion 14 from the upper end portion of the connection port 20 from being pulled into the exhaust port 7 as it is. Further, as clearly shown in FIG. 6, the cross-sectional area of the upstream passage portion 14 is increased as the distance from the first projecting wall 21 increases. As a result, the condensed water collected in the upstream passage portion 14 can be collected on the connection port 20 side with the downstream passage portion 15. Since the condensed water accumulated on the connection port 20 side has a long distance to the exhaust port 7, it is possible to suppress the condensed water from being pulled into the exhaust port 7.

  As described above, in the exhaust gas recirculation device for a vehicle engine according to the present embodiment, when the vehicle engine has a plurality of cylinders, the intake manifold 8 connected to the intake port 6 of each cylinder is used as the cylinder row of the cylinder head 2. Attach to one end in the intersecting direction. Further, an exhaust manifold 9 connected to the exhaust port 7 of each cylinder is attached to the other end of the cylinder head 2 in a direction intersecting the cylinder row. An exhaust gas sensor 19 that detects exhaust gas discharged from the exhaust port 7 is attached to the exhaust manifold 9. An exhaust gas recirculation passage 13 is formed in the cylinder head 2 to recirculate a part of the exhaust gas flowing through the exhaust port 7 to the intake port 6 or the intake manifold 8. The exhaust gas recirculation passage 13 is formed from the exhaust port 7 toward the cylinder row direction on the other end side in the direction intersecting the cylinder row of the cylinder head 2, and becomes lower as the bottom surface 22 moves away from the exhaust port 7 side. An upstream passage portion 14 and a downstream passage portion 15 connected to the upstream passage portion 14 and formed in a direction crossing the cylinder row are provided. The downstream side passage portion 15 is cooled by the cooling water in the cooling water inlet portion (passage) 12. The first projecting wall 21 projecting from the bottom surface 22 of the upstream passage portion 14 toward the ceiling surface 23 and having a preset clearance with respect to the ceiling surface 23 is provided on the exhaust port 7 side of the upstream passage portion 14. Form at the end. Therefore, the condensed water of the exhaust gas generated in the exhaust gas recirculation passage 13 is unlikely to flow to the exhaust port 7 side in the upstream passage portion 14. Moreover, even if the condensed water flows to the exhaust port 7 side in the upstream side passage portion 14, it is possible to suppress the condensed water from being pulled into the exhaust port 7 by the first protruding wall 21. It is possible to prevent the condensed water from scattering into the exhaust manifold 9. As a result, the exhaust gas sensor 19 attached to the exhaust manifold 9 can be protected.

  Further, the upper end portion of the first protruding wall 21 was set at a position higher than the cross-sectional center O of the exhaust port 7 to which the upstream passage portion 14 is connected. Thereby, even if the condensed water is pulled into the exhaust port 7 by the flow of the exhaust gas, the condensed water can be attached to the ceiling surface of the exhaust port 7. Thereby, the condensed water can be shifted from the main flow of the exhaust gas in the exhaust port 7, and the amount of condensed water riding on the flow of the exhaust gas can be reduced. Therefore, it is possible to prevent the condensed water from scattering into the exhaust manifold 9, and as a result, it is possible to protect the exhaust gas sensor 19 attached to the exhaust manifold 9.

  Further, the upper end portion of the first projecting wall 21 was set at a position higher than the upper end portion of the connection port 20 between the upstream side passage portion 14 and the downstream side passage portion 15. As a result, even if the condensed water in the downstream passage portion 15 flows into the upstream passage portion 14 from the upper end portion of the connection port 20, the condensed water is pulled into the exhaust port 7 by the first protruding wall. 21 can be suppressed. Therefore, it is possible to prevent the condensed water from scattering into the exhaust manifold 9, and as a result, it is possible to protect the exhaust gas sensor 19 attached to the exhaust manifold 9.

  Further, the upstream passage portion 14 has a larger cross-sectional area as it is farther from the first projecting wall 21. Thereby, even if condensed water accumulates in the upstream passage portion 14, the condensed water can be collected on the connection port 20 side with the downstream passage portion 15. Since the condensed water accumulated on the connection port 20 side has a long distance to the exhaust port 7, it is possible to suppress the condensed water from being pulled into the exhaust port 7. Therefore, it is possible to prevent the condensed water from scattering into the exhaust manifold 9, and as a result, it is possible to protect the exhaust gas sensor 19 attached to the exhaust manifold 9.

  FIG. 8 is a front view of the upstream-side passage portion 14 of the exhaust gas recirculation passage 13 showing a second embodiment of the exhaust gas recirculation device for a vehicle engine of the present invention. The exhaust gas recirculation device of the present embodiment is similar to the exhaust gas recirculation device of the first embodiment. Therefore, the same constituent elements are denoted by the same reference numerals, and detailed description thereof is omitted. The main configuration of the vehicle engine of the present embodiment is the same as that in FIGS. 1 to 4 of the first embodiment. The main configuration of the exhaust gas recirculation passage 13 of this embodiment is the same as that of FIGS. 5 and 6 of the first embodiment.

  In the exhaust gas recirculation passage 13 of the present embodiment, the configuration in the upstream-side passage portion 14 is changed from that of FIG. 7 of the first embodiment to that of FIG. In the upstream side passage portion 14, a second protruding wall 24 is formed between the first protruding wall 21 and the connection port 20 with respect to the first protruding wall 21 at the end portion on the exhaust port 7 side described above. A third protruding wall 25 is formed between the second protruding wall 24 and the connection port 20. Among these, the second projecting wall 24 is formed to project from the ceiling surface 23 of the upstream passage portion 14 toward the bottom surface 22, and has a preset gap between the second projecting wall 24 and the bottom surface 22. The third projecting wall 25 is formed to project from the bottom surface 22 of the upstream passage portion 14 toward the ceiling surface 23, and has a preset gap between the third projecting wall 25 and the ceiling surface 23. Furthermore, the lower end portion of the second projecting wall 24 is set at a position lower than the upper end portion of the first projecting wall 21, and the upper end portion of the third projecting wall 25 is positioned higher than the lower end portion of the second projecting wall 24. Set to.

  In this way, by forming the plurality of protruding walls 21, 24, and 25 in a protruding manner, the inside of the upstream-side passage portion 14 can have a labyrinth (maze) structure. Therefore, the flow of the condensed water indicated by the white arrow in FIG. 8 can be made into a maze to prevent the condensed water from being pulled into the exhaust port 7. Therefore, it is possible to prevent the condensed water from scattering into the exhaust manifold 9, and as a result, it is possible to protect the exhaust gas sensor 19 attached to the exhaust manifold 9. In particular, as in the present embodiment, when the groove portion 16 is formed on the (other) end surface in the direction intersecting the cylinder row of the cylinder head 2 to form the upstream passage portion 14, the above-described alternate It is easy to form the protruding walls 21, 24, 25.

  Further, in the present embodiment, the concave curved surface 26 is formed by denting the surfaces of the first projecting wall 21, the second projecting wall 24, and the third projecting wall 25 on the side opposite to the exhaust port 7. As a result, as shown by a white arrow in FIG. 8, the condensed water moving to the exhaust port 7 side in the upstream side passage portion 14 hits the concave curved surface 26 of each protruding wall 21, 24, 25, that is, in the opposite direction. It can return to the downstream channel | path part 15 direction, and it can suppress that condensed water is pulled into the exhaust port 7 from the upstream channel | path part 14. FIG. Therefore, it is possible to prevent the condensed water from scattering into the exhaust manifold 9, and as a result, it is possible to protect the exhaust gas sensor 19 attached to the exhaust manifold 9.

  FIG. 9 is a front view of the upstream side passage portion 14 of the exhaust gas recirculation passage 13 showing a third embodiment of the exhaust gas recirculation device for a vehicle engine of the present invention. The exhaust gas recirculation device of the present embodiment is similar to the exhaust gas recirculation device of the first embodiment. Therefore, the same constituent elements are denoted by the same reference numerals, and detailed description thereof is omitted. The main configuration of the vehicle engine of the present embodiment is the same as that in FIGS. 1 to 4 of the first embodiment. The main configuration of the exhaust gas recirculation passage 13 of this embodiment is the same as that of FIGS. 5 and 6 of the first embodiment.

  In the exhaust gas recirculation passage 13 of the present embodiment, a concave groove 27 that is recessed downward is formed between the first protruding wall 21 and the connection port 20 in the bottom surface 22 of the upstream-side passage portion 14. Thereby, as shown by the white arrow in the figure, it is possible to suppress the condensed water from being accumulated in the concave groove 27 and the condensed water being pulled from the upstream passage portion 14 to the exhaust port 7. Therefore, it is possible to prevent the condensed water from scattering into the exhaust manifold 9, and as a result, it is possible to protect the exhaust gas sensor 19 attached to the exhaust manifold 9.

DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Cylinder head 3 Cylinder head cover 4 Crankcase 5 Crankshaft 6 Intake port 7 Exhaust port 8 Intake manifold 9 Exhaust manifold 10 Exhaust pipe 11 EGR valve 12 Cooling water inlet part 13 Exhaust gas recirculation passage 14 Upstream side passage part 15 Downstream Side passage portion 16 Concave groove portion 17 Packing 18 Lid member 19 Exhaust gas sensor 20 Connection port 21 First projecting wall 22 Bottom surface 23 Ceiling surface 24 Second projecting wall 25 Third projecting wall 26 Concave surface 27 Concave groove

Claims (7)

In an exhaust gas recirculation device for a vehicle engine having a plurality of cylinders,
An intake manifold attached to one end of the cylinder head in a direction crossing the cylinder row and connected to an intake port of each cylinder;
An exhaust manifold attached to the other end of the cylinder head in a direction crossing the cylinder row and connected to an exhaust port of each cylinder;
An exhaust gas sensor attached to the exhaust manifold for detecting exhaust gas exhausted from the exhaust port;
An exhaust gas recirculation passage formed in the cylinder head for recirculating a part of the exhaust gas flowing through the exhaust port to the intake port or the intake manifold;
The exhaust gas recirculation passage is formed, and is formed from the exhaust port toward the cylinder row direction on the other end side in the direction intersecting the cylinder row of the cylinder head, and as the bottom surface moves away from the exhaust port side. A lower upstream passage,
The exhaust gas recirculation passage, the downstream passage portion connected to the upstream passage portion and formed in a direction crossing the cylinder row and cooled by the cooling water in the cooling water passage;
A vehicle comprising: a protruding wall formed at an end of the upstream passage portion on the exhaust port side, protruding from the bottom surface toward the ceiling surface, and having a preset gap with respect to the ceiling surface. Engine exhaust gas recirculation system.   2. The exhaust gas recirculation device for a vehicle engine according to claim 1, wherein an upper end portion of the protruding wall is set at a position higher than a cross-sectional center of the exhaust port to which the upstream passage portion is connected.   The exhaust gas recirculation of the vehicle engine according to claim 2, wherein an upper end portion of the protruding wall is set to a position higher than an upper end portion of a connection port between the upstream side passage portion and the downstream side passage portion. apparatus.   The exhaust gas recirculation device for a vehicle engine according to claim 3, wherein the upstream passage portion has a larger cross-sectional area as it is farther from the protruding wall.   When the projecting wall is a first projecting wall, a second projecting wall projecting from the ceiling surface toward the bottom surface between the first projecting wall and the connection port of the upstream passage portion is provided. The exhaust gas recirculation device for a vehicle engine according to claim 3 or 4, wherein the lower end portion of the second projecting wall is formed at a position lower than the upper end portion of the first projecting wall. .   6. The vehicle engine according to claim 5, wherein a concave curved surface is formed by recessing a surface opposite to the exhaust port of at least one of the first projecting wall and the second projecting wall. Exhaust gas recirculation device.   4. The exhaust gas recirculation device for a vehicle engine according to claim 3, wherein a concave groove recessed downward is formed between the projecting wall and the connection port in the bottom surface of the upstream passage portion.

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