JP2012002202A - Exhaust gas recirculation device in internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce noise from a cover plate 17 in a configuration in which: a recessing groove 14 extending in a longitudinal direction of a crankshaft line is formed in an exhaust side surface 5 of a cylinder head 1; an exhaust gas inlet 15 from an exhaust port 8 is opened on one end of the recessing groove and an exhaust gas outlet 16 to an exhaust gas recirculation passage 13 is opened on the other end; and the recessing groove is covered by a cover plate 17 that is joined to the exhaust side surface with a sealing gasket 19 therebetween.SOLUTION: A recess area 20 is provided in an area of the cover plate 17 corresponding to the recessing groove. The gasket 19 is configured to cover both the recessing groove and the recess area. A plurality of through-holes 21 and 22 that communicate between the recessing groove and the recess area are provided in the gasket at an appropriate interval in the longitudinal direction of the recessing groove.

Description

  The present invention relates to an apparatus for recirculating a part of exhaust gas to an intake system in an internal combustion engine in order to clean the exhaust gas.

Patent Documents 1 and 2 as prior art include
“On the exhaust side of the cylinder head where the exhaust port opens, a concave groove is formed so as to extend in the direction of the crankshaft, and an exhaust gas inlet from the exhaust port is formed at one end of the concave groove. Exhaust gas outlets to the exhaust gas recirculation passage provided inside the cylinder are opened at the other end, and a lid plate that covers the entire recessed groove is joined to the exhaust side surface with a sealing gasket interposed therebetween. Exhaust gas recirculation device. "
Is described.

JP 2001-342907 A JP 2002-106420 A

  According to these prior arts, a part of the exhaust gas recirculation path from the exhaust system to the intake system can be constituted by a recessed groove formed in the exhaust side of the cylinder head, so that the number of parts can be reduced and the space can be reduced. Reduction in size and weight can be achieved.

  However, on the other hand, the exhaust gas blows into the portion of the lid plate in the recessed groove, resulting in pulsation existing in the exhaust gas and collision of exhaust gas from the lid plate. There is a problem that high noise is generated outward.

  In particular, this problem, that is, the noise generated outward from the cover plate, is caused when the flange plate for joining the exhaust manifold and the cover plate integrated therewith are made of a relatively thin metal plate (made of sheet metal). It was further increased.

  The present invention has a technical problem to solve this problem.

In order to achieve this technical problem, claim 1
“On the exhaust side of the cylinder head where the exhaust port opens, a concave groove is formed so as to extend in the longitudinal direction of the crankshaft, and an exhaust gas inlet from the exhaust port is formed at one end of the concave groove. The exhaust gas outlet to the exhaust gas recirculation passage provided inside the cylinder is opened at the other end of the cylinder, and a cover plate for closing the entire recessed groove is sandwiched between the exhaust side surfaces and a sealing gasket is interposed therebetween. In the exhaust gas recirculation device formed by joining,
The cover plate is provided with a recess in a portion corresponding to the recess groove, and the gasket is configured to close both the recess groove and the recess with the gasket, and the gasket includes the recess groove and the gasket. A plurality of through holes communicating with the recesses were provided at appropriate intervals in the longitudinal direction of the recess groove. "
It is characterized by that.

Claim 2
“In the first aspect of the present invention, the recess and the plurality of through holes are provided at or near the portion of the exhaust gas inlet to the recess groove.”
It is characterized by that.

Furthermore, claim 3
“In the first aspect of the present invention, the recess and the plurality of through holes are formed by connecting an exhaust gas inlet portion to the concave groove or the vicinity thereof and an exhaust gas outlet portion from the concave groove or the vicinity thereof. Both were provided. "
It is characterized by that.

  According to the configuration of the first aspect, the pulsation of the exhaust gas flowing in the recessed groove on the cylinder head side is transmitted to the recess provided on the lid plate side through the through hole provided in the gasket therebetween.

  In this case, a plurality of the through holes are provided and provided at an appropriate interval in the longitudinal direction of the recessed groove, so that a through hole at a location close to the exhaust gas inlet to the recessed groove among these through holes. And the phase of the pulsation transmitted to the recess is shifted between the through hole at a location far from the exhaust gas inlet.

  That is, the pulsation in the recessed groove on the cylinder head side is transmitted to the recessed portion on the lid plate side out of phase from each of the plurality of passages, and interferes with each other in the recessed portion to be attenuated. Therefore, noise generated outward from the cover plate can be greatly reduced, and low cost can be achieved by providing the gasket with a passage.

  According to the second aspect of the present invention, the noise generated outward from the cover plate is particularly large in the vicinity of the exhaust gas inlet to the recessed groove or in the vicinity thereof, so that this large noise can be reliably reduced.

  The noise generated outwardly from the lid plate is caused by pulsation that flows backward from the exhaust gas recirculation passage provided inside the cylinder head to the recessed groove. According to the configuration of claim 3, Since noise caused by pulsation flowing backward from the exhaust gas recirculation passage can be reliably reduced by the same principle, there is an advantage that the above-described effect can be promoted.

It is a partially notched top view which shows the principal part in 1st Embodiment. FIG. 2 is a side view taken along the line II-II in FIG. 1. FIG. 3 is an enlarged sectional view taken along line III-III in FIG. 2. FIG. 4 is an enlarged sectional view taken along line IV-IV in FIG. 2. It is an exploded view in FIG. It is a plane sectional view showing the important section in a 2nd embodiment. It is an exploded view in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 5 show a first embodiment.

  In these drawings, reference numeral 1 denotes a cylinder head in an internal combustion engine having a plurality of cylinders 3 arranged along a crank axis 2.

  In the cylinder head 1, exhaust ports 4 from the cylinders 3 are provided so as to open to one side surface 5 of the left and right side surfaces 5, 6 of the cylinder head 1, that is, to the exhaust side surface 5. .

  Further, the cylinder head 1 is provided with an intake port 7 to each cylinder 3 so as to open to the other side surface 6 of the left and right side surfaces 5, 6, that is, the intake side surface 6.

  An exhaust manifold 8 for the exhaust port 4 of each cylinder 3 is detachably joined to the exhaust side surface 5 of the cylinder head 1 with a sealing gasket 9 made of a heat-resistant material such as a thin metal plate interposed therebetween. Yes.

  The exhaust manifold 8 includes a joining flange plate 10 fastened to the exhaust side surface 5 by a plurality of bolts 11 and an exhaust pipe 12 joined to the joining flange plate 10.

  An intake manifold (not shown) to each cylinder 3 is joined to the intake side surface 6 of the cylinder head 1.

  Further, an exhaust gas recirculation passage 13 configured to extend from the exhaust side surface 5 toward the intake side surface 6 is formed at one end portion of the cylinder head 1 in the direction of the crank axis 2.

  A portion of the exhaust gas recirculation passage 13 on the intake side 6 side communicates with an intake manifold on the intake side 6, and exhaust gas flowing in the exhaust gas recirculation passage 13 toward the intake side 6 is The refrigerant is recirculated so as to be distributed to each cylinder 3 through the intake manifold.

  A concave groove 14 is formed in the exhaust side surface 5 of the cylinder head 1 between the exhaust port 4 and the exhaust gas recirculation passage 13 so as to extend in the longitudinal direction of the crank axis 2. ing.

  The recessed groove 14 is formed simultaneously with a casting mold when the cylinder head 1 is cast, or is formed by machining after the cylinder head 1 is cast. The exhaust gas inlet 15 from the exhaust port 4 is open, while the other end 14b is open to the exhaust gas outlet 16 to the exhaust gas recirculation passage 13.

  On the other hand, the joining flange plate 10 in the exhaust manifold 8 is integrally provided with a cover plate 17 extending along the exhaust side surface 5 so as to close the recessed groove 14. The lid plate 17 is detachably joined to the exhaust side surface 5 by fastening with a plurality of bolts 18 with a sealing gasket 19 made of a heat-resistant material such as a thin metal plate interposed therebetween.

  Thus, the recessed groove 14 is formed in a closed flow passage, and the exhaust port 4 is communicated with the exhaust gas recirculation passage 13 by this flow passage.

  In the illustrated embodiment, the lid plate 17 that closes the recessed groove 14 is formed integrally with the joining flange plate 10 in the exhaust manifold 8, and a sealing gasket 19 for the lid plate 17 is further provided. , The sealing gasket 9 for the joining flange plate 10 is integrated with the sealing flange 9, but the lid plate 17 is separated from the joining flange plate 10 in the exhaust manifold 8, and The sealing gasket 19 for the lid plate 17 can be separated from the sealing gasket 9 for the joining flange plate 10.

  The cover plate 17 has a recess 20 formed in a groove shape along the recess groove 14 so as to extend from a portion 20 a corresponding to the exhaust gas inlet 15 to a portion 20 b corresponding to the exhaust gas outlet 16. It is dented to the shape.

  In the illustrated embodiment, the lid plate 17 is made of a metal plate, and the metal plate is pressed to form the groove-shaped recess 20. As an embodiment, the recess provided in the lid plate 17 is not divided into a groove shape, and is divided into a portion 20a corresponding to the exhaust gas inlet 15 and a portion 20b corresponding to the exhaust gas outlet 16. Can be provided.

  On the other hand, a sealing gasket 19 interposed between the exhaust side surface 5 of the cylinder head 1 and the lid plate 17 is configured to block both the recessed groove 14 and the recessed portion 20 by the gasket 19.

  In the gasket 19, a portion corresponding to the exhaust gas inlet 15 is provided with a plurality of first through holes 21 communicating the recessed groove 14 and the recessed portion 20 with each other in the longitudinal direction of the recessed groove 14. S1 is provided.

  Further, a portion of the gasket 19 corresponding to the exhaust gas outlet 16 is provided with a plurality of second through holes 22 that communicate the recessed groove 14 and the recessed portion 20 with each other in the longitudinal direction of the recessed groove 14. It is provided at an appropriate interval S2.

  In this configuration, the pulsation of the exhaust gas flowing in the recessed groove 14 on the cylinder head 1 side is caused by a plurality of through holes 21 and 22 provided in the gasket 19 between the recesses 20 provided on the lid plate 14 side. Communicate through.

  In this case, a strong pulsation from the exhaust gas inlet 15 exists in a portion of the recessed groove 14 where the exhaust gas inlet 15 opens, and the pulsation in this portion is in the longitudinal direction in the recess 20. The phase is shifted from each first through hole 21 provided at an appropriate interval S1. Then, the pulsations whose phases are shifted are attenuated by interfering with each other in the recess 20.

  Further, a pulsation flowing backward from the exhaust gas outlet 16 is present in a portion of the recessed groove 14 where the exhaust gas outlet 16 is opened, and the pulsation in this portion is longitudinal in the recess 20. The phase is shifted from each second through hole 22 provided at an appropriate interval S2 in the direction, and the pulsations having the phase shifted in the recess 20 are attenuated by interfering with each other.

  Next, FIGS. 6 and 7 show a second embodiment.

  In the second embodiment, an integral gasket 9 and 19 between the exhaust side surface 5 of the cylinder head 1 and the exhaust manifold 8 and the lid plate 14 is replaced with a thin metal plate A1 on the cylinder head 1 side. And a thin metal plate A2 on the side of the exhaust manifold 8 and the lid plate 14, and also in this case, the portion corresponding to the exhaust gas inlet 15 of the two metal plates A1 and A2 A plurality of first through holes 21 are provided at an appropriate interval S1, and a plurality of second through holes 22 are provided at an appropriate interval S2 in a portion corresponding to the exhaust gas outlet 16 of the two metal plates A1, A2. It has been.

  Other configurations are the same as those of the first embodiment, and the same operations and effects as those of the first embodiment are achieved.

  In the second embodiment, the two metal plates A1 and A2 constituting the integrated gaskets 9 and 19 are provided with minute gaps between the exhaust ports 4 and the recessed grooves 14 between them. The two metal plates A1 and A2 are resistant to their elasticity when the exhaust manifold 8 and the cover plate 14 are fastened to the exhaust side surface 5 of the cylinder head 1. Thus, it is configured to exhibit high sealing performance by being deformed so as to be in close contact with each other.

1 Cylinder Head 2 Crank Axis 3 Cylinder 4 Exhaust Port 5 Cylinder Head Exhaust Side 8 Exhaust Manifold 13 Exhaust Gas Recirculation Passage 14 Concave Groove 15 Exhaust Gas Inlet 16 Exhaust Gas Outlet 17 Cover Plate 19 Sealing Gasket 20 Concave 21 First Pass Hole 22 Second hole

Claims (3)

A concave groove is formed on the exhaust side of the cylinder head where the exhaust port is open so as to extend in the longitudinal direction of the crankshaft, and an exhaust gas inlet from the exhaust port is provided at one end of the concave groove. Exhaust gas outlets to the exhaust gas recirculation passage provided inside the cylinder are opened at the other end, and a lid plate that covers the entire recessed groove is joined to the exhaust side surface with a sealing gasket interposed therebetween. In the exhaust gas recirculation device comprising:
The cover plate is provided with a recess in a portion corresponding to the recess groove, and the gasket is configured to close both the recess groove and the recess with the gasket, and the gasket includes the recess groove and the gasket. An exhaust gas recirculation apparatus for an internal combustion engine, wherein a plurality of through holes communicating with the recesses are provided at appropriate intervals in the longitudinal direction of the recess groove.   2. An exhaust gas recirculation apparatus for an internal combustion engine according to claim 1, wherein the recess and the plurality of through holes are provided at or near an exhaust gas inlet to the recess groove.   2. The recess according to claim 1, wherein the recess and the plurality of through-holes are provided both at a portion of the exhaust gas inlet to the recessed groove or the vicinity thereof and a portion of the exhaust gas outlet from the recessed groove or the vicinity thereof. An exhaust gas recirculation device for an internal combustion engine, characterized by being provided in the internal combustion engine.

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