JP5817676B2 - Exhaust cooling device - Google Patents

Description

  The present invention relates to an exhaust cooling device provided in an exhaust gas recirculation device for a vehicle internal combustion engine.

  Conventionally, an exhaust cooling device generally passes exhaust gas (EGR gas, recirculated exhaust gas) through an EGR cooler core in a housing, and between cooling water guided between the housing and the EGR cooler core and exhaust gas passing through the EGR cooler core. The exhaust gas recirculating to the intake side is cooled by exchanging heat at.

  A conventional exhaust cooling device of this type includes, for example, a first part made of steel, stainless steel, plastic, or ceramics, and a second part made of aluminum, and the first part and the second part are joined to a joining region. Are well bonded to each other by friction stir welding (for example, see Patent Document 1).

JP 2012-78084 A

  However, what is described in Patent Document 1 is the case where the EGR cooler core as the first part is made of stainless steel and the housing as the second part is made of aluminum. Due to the difference, metal fatigue occurs in both joints, and there is a problem that the robustness of the sealing performance of the joints is lowered.

  On the other hand, by using a structure in which the EGR cooler core and the housing are sealed by a sealing member such as an O-ring instead of welding, it is possible to avoid a decrease in the robustness of the sealing performance due to metal fatigue. There is a problem that the rubber material used in the above is deteriorated when exposed to high-temperature exhaust gas.

  The present invention has been made in view of the problems of the prior art as described above, and can seal the sealing member from high-temperature exhaust gas to improve the robustness of the sealing performance. It is an object of the present invention to provide an exhaust cooling device that can suppress the shake of the EGR cooler core due to vibration.

In order to solve the above-described problems, an exhaust cooling device according to the present invention includes (1) an EGR cooler core having an internal passage for returning exhaust gas of an internal combustion engine capable of exhaust gas recirculation to the intake side, and the EGR cooler core inward. A hole diameter in which the EGR cooler core can be inserted into at least one of the upstream side and the downstream side of the EGR cooler core in the exhaust gas recirculation direction while forming a cooling water passage between the EGR cooler core. An exhaust cooling device comprising: a housing having a pipe connection portion in which a connection hole is formed; and an EGR pipe having a connection end connected to the pipe connection portion of the housing, wherein the EGR cooler core includes: the has opposing ends facing the connecting end portion side of the EGR pipe, between the outer peripheral side and the inner peripheral wall surface of the connecting hole of the counter end portion, the cold Water passage from the outside of the inner passage and the housing is mounted a sealing member for partitioning the liquid-tight manner, between the pipe connection portion of the said connecting end portion of the EGR pipe housing, the central portion A gasket member that is formed of an annular member that extends into the connection hole and that hermetically blocks the internal passage and the inside of the EGR pipe from the outside of the housing is attached to the gasket member. A central portion of the EGR cooler core abuts against the opposed end portion of the EGR cooler core, and is elastically compressed between the opposed end portion of the EGR cooler core and the connected end portion of the EGR pipe, An elastic gas seal portion for blocking exhaust gas passing through the internal passage from the seal member is provided.

  With this configuration, the elastic gas seal portion of the gasket member can block the seal member from high-temperature exhaust gas, and can prevent the seal member from being exposed to the exhaust gas and deteriorating the sealing performance.

  Further, since the elastic gas seal portion is elastically compressed between the opposing end portion of the EGR cooler core and the connection end portion of the EGR pipe, the EGR cooler core is elastically supported in the housing. Therefore, the EGR cooler core shake due to thermal expansion of the EGR cooler core or vibration of the internal combustion engine can be suppressed.

  Therefore, it is possible to provide an exhaust cooling device capable of improving the robustness of the sealing performance by blocking the sealing member from the high-temperature exhaust gas and suppressing the fluctuation of the EGR cooler core due to thermal expansion and engine vibration. Can do.

  In the exhaust cooling device according to the above (1), (2) the EGR cooler core is connected to the EGR cooler core on one side of the upstream side and the downstream side instead of the connection end of the EGR pipe. The flow rate of the exhaust gas passing through the internal passage is variably controlled, and an EGR valve, part of which is in contact with the cooling water passing through the cooling water passage, is provided on the other side of the upstream side and the downstream side of the EGR cooler core. The seal member and the elastic gas seal portion are preferably disposed.

  With this configuration, during operation of the internal combustion engine, the EGR valve can be cooled with the cooling water passing through the cooling water passage, and the EGR valve can be prevented from freezing at low temperatures.

In the exhaust cooling apparatus according to (1) or (2), and (3) the housing, the connection holes of the upstream and downstream located upstream and downstream of the internal passage of the EGR cooler core which has, it is preferable that the upstream side and the inner peripheral wall surface of the connection hole on the downstream side is composed of a plurality of dividable multiple housings divided bodies, respectively.

  With this configuration, even if the shape of the EGR cooler core is curved or enlarged to increase the contact area with the cooling water, the housing can be divided and the EGR cooler core can be assembled in the housing, so that the cooling capacity can be increased. it can.

  In the exhaust cooling device described in the above (1) to (3), it is preferable that (4) the sealing member includes a material having rubber elasticity.

  With this configuration, it is possible to prevent the sealing member from being deteriorated by the heat of the exhaust gas even if the sealing member is made of a material having rubber elasticity.

  In the exhaust cooling device according to the above (1) to (4), (5) the elastic gas seal portion of the gasket member includes the opposing end portion of the EGR cooler core and the connection end portion of the EGR pipe. It is preferably formed in a bellows shape that can expand and contract in the opposite direction.

  With this configuration, the elastic gas seal portion is formed in a bellows shape that can be expanded and contracted, whereby elasticity like a spring can be given to the elastic gas seal portion.

  In the exhaust cooling device described in (1) to (5) above, (6) the opposed end portion of the EGR cooler core has an annular convex shape protruding radially outward from a main body portion of the EGR cooler core. The elastic gas seal portion of the gasket member is preferably compressed between one side surface of the annular convex opposing end portion and the connection end portion of the EGR pipe.

  With this configuration, the opposing end portion of the EGR cooler core has an annular convex shape that protrudes radially outward, so that the contact area of the opposing end portion with the elastic gas seal portion can be secured sufficiently stably, so that the elastic gas seal portion Thus, the exhaust gas passing through the internal passage can be reliably blocked from the seal member.

  According to the present invention, the exhaust cooling device can block the seal member from the high-temperature exhaust gas to improve the robustness of the sealing performance, and can suppress the EGR cooler core shake due to thermal expansion or engine vibration. Can be provided.

1 is a top view showing a schematic configuration of an exhaust cooling device according to a first embodiment of the present invention. It is a top view which shows schematic structure of the other example of the exhaust-air-cooling apparatus which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the attachment state of the EGR cooler core to the housing of the exhaust-air-cooling apparatus which concerns on the 1st Embodiment of this invention, and is AA arrow sectional drawing of FIG. (A), (b) is sectional drawing which shows the shape of the elastic gas seal part of the exhaust-air-cooling apparatus which concerns on the 1st Embodiment of this invention. It is a top view which shows schematic structure of the exhaust-air-cooling apparatus which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the attachment state of the EGR cooler core to the housing of the exhaust-air-cooling apparatus which concerns on the 2nd Embodiment of this invention, and is AA arrow sectional drawing of FIG. It is a perspective view which shows the housing of the exhaust-air-cooling apparatus which concerns on the 3rd Embodiment of this invention. It is a front view which shows the housing of the exhaust-air-cooling apparatus which concerns on the 3rd Embodiment of this invention. It is a perspective view which shows the lower side division body of the housing of the exhaust-air-cooling apparatus which concerns on the 3rd Embodiment of this invention. (A), (b) is sectional drawing which shows the shape of the EGR cooler core of the exhaust-air-cooling apparatus which concerns on the 3rd Embodiment of this invention. (A), (b) is sectional drawing which shows the structure of the elastic gas seal part and EGR cooler core housing of the exhaust-air-cooling apparatus which concern on the 3rd Embodiment of this invention. It is a side view which shows the attachment aspect to the cylinder block of the exhaust-air-cooling apparatus which concerns on the 3rd Embodiment of this invention. It is a perspective view of the cylinder block to which the exhaust-air-cooling apparatus which concerns on the 3rd Embodiment of this invention is attached. (A), (b) is the perspective view and side view which show the housing of the exhaust-air-cooling apparatus based on the 3rd Embodiment of this invention. (A) is a top view which shows the shape of the EGR cooler core of the exhaust-air-cooling apparatus which concerns on the 4th Embodiment of this invention, (b) is BB arrow sectional drawing of (a). (A) is a top view which shows the other example of the shape of the EGR cooler core of the exhaust-air-cooling apparatus which concerns on the 4th Embodiment of this invention, (b) is BB arrow sectional drawing of (a). It is. (A) is a top view which shows the other example of the shape of the EGR cooler core of the exhaust-air-cooling apparatus which concerns on the 4th Embodiment of this invention, (b) is BB arrow sectional drawing of (a). It is.

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

(First embodiment)
1 to 4 show an exhaust cooling device according to a first embodiment of the present invention.

  In FIG. 1, an EGR cooler 23 (exhaust cooling device) is mounted on a multi-cylinder engine 10 (internal combustion engine) as a part of an EGR device 20 (exhaust gas recirculation device).

  The engine 10 includes an EGR device 20 that recirculates and recirculates part of the exhaust of the engine 10 from the exhaust manifold 14 side to the intake manifold 13 side.

  The EGR device 20 has an exhaust gas recirculation EGR gas passage 21 (exhaust gas recirculation passage) for communicating the exhaust passage 14 a in the exhaust manifold 14 and the intake passage 13 a in the intake manifold 13.

  In the middle of the EGR gas passage 21, an EGR cooler 23 is provided as an exhaust cooling device that cools the exhaust gas recirculated through the EGR gas passage 21. An electromagnetic EGR valve (exhaust recirculation valve) (not shown) for adjusting the exhaust gas recirculation amount is provided in the middle of the EGR gas passage 21.

  The EGR gas passage 21 is an exhaust gas recirculation passage that recirculates part of the exhaust gas from the exhaust passage 14 a side to the intake passage 13 a side of the engine 10, and a part of the EGR gas passage 21 is an exhaust gas in the EGR cooler 23. This is a cooling passage for (EGR gas, recirculated exhaust gas).

  The EGR cooler 23 is provided in a housing portion 31 integrally formed as one part of the cylinder head 12 at an end portion of the cylinder head 12 made of an aluminum die-cast alloy or the like. In other words, in FIG. 1, the EGR cooler 23 is disposed inside the cylinder head 12 with the cylinder head 12 as a housing (housing). The EGR cooler 23 is a heat exchanger that exchanges heat between the cooling water and the exhaust gas from the exhaust passage 14a inside the housing portion 31, and cools the exhaust gas by this heat exchange. It has become.

  Specifically, the housing portion 31 is formed at an end portion on the downstream side of the cooling water that passes through the inside of the cylinder head 12, and the cylinder head 12 has a width in the height direction and the width direction of the cylinder head 12. A relatively large concave shape having substantially the same width is formed. The housing part 31 is integrally provided with a water outlet 72 for discharging cooling water.

  Thereby, in the housing part 31, the cooling water outlet passage 30 (substantially rectangular parallelepiped shape with a relatively large volume) that allows the cooling water that has cooled each part in the cylinder head 12 to flow out from the water outlet 72 to a water pump (not shown). 3) is formed.

  As shown in FIG. 2, the EGR cooler 23 has an exhaust from the coolant and the exhaust passage 14 a side in a head rear housing 32 formed separately from the cylinder head 12 at the end of the cylinder head 12. A heat exchanger that cools the exhaust gas by exchanging heat with the gas may be used.

  That is, as a housing of the EGR cooler 23, a head rear housing 32 having a separate structure from the cylinder head 12 as shown in FIG. 2 may be used instead of the housing 31 having a structure integral with the cylinder head 12 as shown in FIG. it can. The head rear housing 32 is fixed to the cylinder head 12 with bolts or the like, and an internal space through which cooling water passes communicates with the internal space of the cylinder head 12.

  Hereinafter, the internal structure of the housing part 31 of FIG. 1 will be described. Note that the interior of the head rear housing 32 of FIG.

  As shown in FIG. 3, an EGR cooler core 33 through which the exhaust gas passes is accommodated in the housing portion 31 in a posture oriented in a direction orthogonal to the direction in which the cooling water passes in the cooling water outlet passage 30.

  The EGR cooler core 33 is made of a material having a small linear expansion coefficient with respect to the housing portion 31, for example, a pipe made of stainless steel, and is a flow direction of the cooling water in the cooling water outlet passage 30 in FIGS. 1 to 3. It extends in the up-down direction substantially orthogonal to the left-right direction (direction from right to left).

  Further, the EGR cooler core 33 forms an internal passage 34 that becomes a part of the EGR gas passage 21 of the engine 10 on the inner peripheral side thereof, and contacts the cooling water in the cooling water outlet passage 30 on the outer peripheral side thereof. , And are supported by the housing part 31 at both ends in the axial direction.

  In the EGR gas passage 21, a passage portion 21 a closer to the exhaust passage 14 a than the internal passage 34 is formed by an exhaust side EGR pipe 36 interposed between the exhaust manifold 14 and the housing portion 31.

  A passage portion 21 b on the intake passage 13 a side of the internal passage 34 in the EGR gas passage 21 is formed by an intake side EGR pipe 37 interposed between the intake manifold 13 and the housing portion 31.

  Flange-shaped EGR pipe flanges 51 and 52 are respectively provided at the end portions of the EGR pipes 36 and 37 on the housing portion 31 side.

  Further, as shown in FIG. 3, the housing portion 31 is formed with a plurality of bolt hole portions 41 for fastening the EGR pipe flanges 51 and 52 of the EGR pipes 36 and 37.

  The portion of the housing portion 31 where the bolt hole portion 41 is formed is a piping connection portion 43, 44 for connecting the EGR pipe flanges 51, 52 to the housing portion 31 by bolt fastening, and this piping connection portion 43, Connection holes 45 and 46 are formed in 44.

  EGR pipe gaskets 55 and 56 made of metal such as stainless steel are provided between the EGR pipe flanges 51 and 52 and the pipe connecting portions 43 and 44.

  The EGR pipe gaskets 55 and 56 are positioned by being sandwiched between the EGR pipe flanges 51 and 52 and the pipe connection parts 43 and 44 in a state where the EGR pipe flanges 51 and 52 are bolted to the pipe connection parts 43 and 44. Is fixed, and the space between the EGR pipe flanges 51 and 52 and the pipe connecting portions 43 and 44 is sealed.

  The EGR pipe gaskets 55 and 56 are formed in an annular shape as a whole, and an elastic gas seal portion 55a that is elastically deformable toward the EGR cooler core 33 side by being formed in a bellows shape at the center thereof. 56a.

  The elastic gas seal portions 55a and 56a have a substantially cylindrical shape with a short axial length, and have a bellows shape whose cross section is curved around the end portion 33a or 33b of the EGR cooler core 33 in the radial direction of the EGR cooler core 33. It has a formed spring structure and is integrally provided at the center of the EGR pipe gaskets 55 and 56.

  The elastic gas seal portions 55a and 56a are elastically pressed against the EGR cooler core housings 59 and 60 at the surfaces facing the EGR cooler core housings 59 and 60, which will be described later.

  Here, when the EGR cooler core 33 expands and contracts with respect to the housing part 31 due to a difference in thermal expansion with the housing part 31, the elastic gas seal parts 55a and 56a extend and contract the EGR cooler core 33 according to the expansion and contraction (this embodiment). Then, by deforming in a direction that coincides with the axial direction), it is possible to suppress the occurrence of stress due to the difference in thermal expansion in the EGR cooler core 33 and the housing part 31.

  The elastic gas seal portions 55 a and 56 a are configured to suppress vibration generated in the EGR cooler core 33 by elastically supporting the EGR cooler core 33 in the housing portion 31.

The shape of the elastic gas seal portions 55a and 56a is not limited to the shape shown in FIG. For example, the elastic gas seal portion 55a may have a configuration having two curved portions on the cross section shown in FIG. 4A, or one curved portion on the cross section shown in FIG. 4B. The structure which has may be sufficient.

  That is, the elastic gas seal portions 55a and 56a are provided with a spring structure that can be elastically deformed by forming a bellows shape having a folded shape having at least one folding shape and a curved shape. Moreover, the EGR pipe gaskets 55 and 56 having the elastic gas seal portions 55a and 56a are not limited to stainless steel, and can be made of a material that can have heat resistance and springiness.

  On the other hand, the EGR cooler core 33 has EGR cooler core housings 59 and 60 facing the EGR pipe flanges 51 and 52 side of the EGR pipes 36 and 37 at at least one end thereof, for example, both end portions 33a and 33b. doing.

  Seal members 63 and 64 that partition the cooling water outlet passage 30 from the outside of the internal passage 34 and the housing portion 31 in a liquid-tight manner are mounted on the outer peripheral sides of the EGR cooler core housings 59 and 60.

  The EGR cooler core housings 59 and 60 have an annular convex shape projecting radially outward from the main body portion of the EGR cooler core 33. In the present embodiment, the EGR cooler core housings 59 and 60 are formed in an annular shape having a substantially U-shaped cross section. Yes.

  The elastic gas seal portions 55 a and 56 a of the EGR pipe gaskets 55 and 56 are compressed between one side surface of the EGR cooler core housings 59 and 60 and the EGR pipe flanges 51 and 52 of the EGR pipes 36 and 37.

  The EGR cooler core housings 59 and 60 are joined to the EGR cooler core 33 by welding or brazing at the inner periphery thereof, and seal members 63 and 64 are mounted at the outer periphery thereof.

  Thus, by making the cross section of the EGR cooler core housings 59, 60 substantially U-shaped, the heat of the EGR cooler core 33 is transmitted to the seal members 63, 64 via the EGR cooler core housings 59, 60. Is suppressed.

  On the outer peripheral portions of the EGR cooler core housings 59 and 60, recesses to which the seal members 63 and 64 are attached are formed. The EGR cooler core 33 is assembled into the housing portion 31 in a state where the EGR cooler core housings 59 and 60 are fixed to both ends, and the seal members 63 and 64 are attached to the outer peripheral portions of the EGR cooler core housings 59 and 60. Done. As the sealing members 63 and 64, an annular O-ring made of a rubber material or a rubber gasket can be used.

  Specifically, one of the connection holes 45 and 46 of the housing portion 31 is formed to have a larger diameter than the other, and the EGR cooler core 33 is connected to the EGR cooler core 33 with the larger diameter side of the connection holes 45 and 46 as an inlet. The EGR cooler core 33 is assembled into the housing portion 31 by fixing the cooler core housings 59 and 60 and inserting the assembly with the seal members 63 and 64 attached thereto.

  In FIG. 3, φa which is the diameter of the connection hole 45 is formed larger than φb which is the diameter of the connection hole 46, and the EGR cooler core 33 is assembled using the connection hole 45 as an inlet. Further, the EGR cooler core housing 59 and the seal member 63 are formed larger in diameter than the EGR cooler core housing 60 and the seal member 64 in order to cope with the difference in diameter between the connection hole 45 and the connection hole 46.

  When assembling the EGR cooler core 33 into the housing portion 31, the assembling operator fixes the assembly in which the EGR cooler core housings 59 and 60 are fixed to the EGR cooler core 33 and the seal members 63 and 64 are mounted on the inlet side. In a state where the seal member 64 on the back side is properly inserted into the EGR cooler core housing 60 in a state where it is generally inserted into the connection hole 45 formed with a certain large diameter, the EGR cooler core housing 60 and the connection hole 46 Whether or not the gap is sealed is visually confirmed from the gap between the connection hole 45 and the EGR cooler core 33, and assembly is performed.

  In the present embodiment, φa which is the diameter of the connection hole 45 is formed larger than φb which is the diameter of the connection hole 46, so that it is easy to confirm the installation state of the seal member 64 visually from the connection hole 45. Therefore, the reliability of the assembling work of the EGR cooler core 33 into the housing portion 31 is improved, and as a result, the robustness of the sealing performance is improved.

  Next, the operation will be described.

  In the EGR cooler 23 and the EGR device 20 of the present embodiment configured as described above, when high-temperature exhaust gas passes through the EGR cooler core 33 during operation of the engine 10, the housing portion through which the EGR cooler core 33 passes cooling water. Elongates to 31 due to the difference in thermal expansion. At this time, the elastic gas seal portions 55a and 56a interposed between the housing portion 31 and the EGR cooler core 33 are compressed and contracted in the axial direction so as to absorb the extension of the EGR cooler core 33.

  On the other hand, when the EGR cooler core 33 is cooled by the cooling water in the cooling water outlet passage 30 and contracts with respect to the housing portion 31, the elastic gas seal portions 55a and 56a are provided between the housing portion 31 and the EGR cooler core 33. It elastically recovers to absorb the contraction of 33 and expands.

  For this reason, the EGR cooler core 33 and the housing part 31 are not subjected to large thermal stress due to the difference in thermal expansion.

  Further, since the EGR cooler core 33 is elastically supported by the housing portion 31 by the elastic gas seal portions 55a and 56a of the EGR pipe gaskets 55 and 56, vibration of the EGR cooler core 33 can be suppressed.

  In addition, due to the pressure contact between the elastic gas seal portions 55a and 56a of the EGR pipe gaskets 55 and 56 and the EGR cooler core housings 59 and 60 of the EGR cooler core 33, high-temperature exhaust gas flows from the inside of the EGR cooler core 33 to the seal members 63 and 64. Since leakage to the side is prevented, the sealing members 63 and 64 are blocked from the high-temperature exhaust gas, and the robustness of the sealing performance can be improved. Further, since the elastic gas seal portions 55a and 56a are elastically compressed between the EGR cooler core housings 59 and 60 of the EGR cooler core 33 and the connection end portions of the EGR pipes 36 and 37, the EGR cooler core 33 is compressed. Is elastically supported in the housing portion 31, so that the EGR cooler core 33 can be prevented from shaking due to thermal expansion of the EGR cooler core 33 and vibration of the engine 10.

  As described above, in the present embodiment, the EGR cooler core 33 includes the EGR cooler core housings 59 and 60 facing the EGR pipe flanges 51 and 52 of the EGR pipes 36 and 37, and the EGR cooler core housing 59, Seal members 63 and 64 for liquid-tightly partitioning the cooling water outlet passage 30 from the internal passage 34 and the outside of the housing portion 31 are mounted on the outer peripheral side of the 60, and the EGR pipe flanges 51 of the EGR pipes 36 and 37 are installed. 52 and EGR pipe gaskets 55 and 56 are installed between the pipe connection portions 43 and 44 of the housing portion 31 to hermetically block the inside of the internal passage 34 and the EGR pipes 36 and 37 from the outside of the housing portion 31. The EGR pipe gaskets 55 and 56 include an EGR cooler core housing of the EGR cooler core 33. 9 and 60 and elastic gas seal portions 55a and 56a which are elastically compressed between the EGR pipe flanges 51 and 52 of the EGR pipes 36 and 37 and block the exhaust gas passing through the internal passage 34 from 63 and 64. It has been.

  With this configuration, the elastic gas seal portions 55a and 56a of the EGR pipe gaskets 55 and 56 can shut off the seal members 63 and 64 from the high-temperature exhaust gas, and the seal members 63 and 64 are exposed to the exhaust gas to deteriorate the sealing performance. This can be prevented.

  Further, since the elastic gas seal portions 55a and 56a are elastically compressed between the EGR cooler core housings 59 and 60 of the EGR cooler core 33 and the connection end portions of the EGR pipes 36 and 37, the EGR cooler core 33 is compressed. Is elastically supported in the housing portion 31, so that the EGR cooler core 33 can be prevented from shaking due to thermal expansion of the EGR cooler core 33 and vibration of the engine 10.

  Therefore, the sealing members 63 and 64 can be shielded from the high-temperature exhaust gas to improve the robustness of the sealing performance, and the vibration of the EGR cooler core 33 due to thermal expansion and vibration of the engine 10 can be suppressed.

  Moreover, in this Embodiment, the sealing members 63 and 64 are comprised including the raw material which has rubber elasticity.

  With this configuration, even if the seal members 63 and 64 are made of a material having rubber elasticity, it is possible to prevent the seal members 63 and 64 from being deteriorated by the heat of the exhaust gas.

  In the present embodiment, the elastic gas seal portions 55a and 56a of the EGR pipe gaskets 55 and 56 include the EGR cooler core housings 59 and 60 of the EGR cooler core 33 and the EGR pipe flanges 51 and 52 of the EGR pipes 36 and 37, respectively. It is formed in a bellows shape that can be expanded and contracted in the opposite direction.

  With this configuration, the elastic gas seal portions 55a and 56a are formed in a bellows shape that can be expanded and contracted, whereby elasticity like a spring can be imparted to the elastic gas seal portions 55a and 56a.

  In the present embodiment, the EGR cooler core housings 59 and 60 of the EGR cooler core 33 have an annular convex shape that protrudes radially outward from the main body portion of the EGR cooler core 33, and the elasticity of the EGR pipe gaskets 55 and 56. The gas seal portions 55 a and 56 a are compressed between one side surface of the annular convex EGR cooler core housings 59 and 60 and the EGR pipe flanges 51 and 52 of the EGR pipes 36 and 37.

  With this configuration, the EGR cooler core housings 59 and 60 of the EGR cooler core have an annular convex shape that protrudes radially outward, so that the contact area of the EGR cooler core housings 59 and 60 with respect to the elastic gas seal portions 55a and 56a is sufficiently large. Since it can ensure stably, the exhaust gas which passes the internal channel | path 34 can be reliably interrupted | blocked from the sealing members 63 and 64 by the elastic gas seal parts 55a and 56a.

(Second Embodiment)
5 and 6 show the configuration of the main part of the exhaust cooling device according to the second embodiment of the present invention. Note that the same or similar components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and only differences from the first embodiment will be described below.

  As shown in FIG. 5, in the present embodiment, the flow rate of the exhaust gas passing through the EGR cooler core 33 is controlled at the end of the EGR pipe 37 instead of the EGR pipe flange 52 of the first embodiment. An EGR valve 80 is provided.

  As shown in FIG. 6, the EGR valve 80 includes a flange portion 81 fixed to the housing portion 31 by a bolt 74, a valve body 82 provided in the flange portion 81, and the valve body 82 being open. A discharge port 83 for discharging the exhaust gas to the EGR pipe 37 side, an electromagnetic solenoid 84 for opening and closing the valve body 82, and a spring 85 are provided.

  The EGR cooler core 33 and the EGR valve 80 are integrally configured by an EGR valve connection housing 86 fixed to both the EGR cooler core 33 and the EGR valve 80.

  Specifically, the EGR cooler core 33 and the EGR valve connection housing 86 and the EGR valve 80 and the EGR valve connection housing 86 are joined by welding or brazing.

  Further, an EGR pipe gasket 57 is provided between the flange portion 81 of the EGR valve 80 and the housing portion 31. The EGR pipe gasket 57 is made of a metal such as stainless steel, and liquid-tightly blocks between the flange portion 81 of the EGR valve 80 and the housing portion 31.

  That is, the EGR pipe gasket 57 serves as a water seal that prevents cooling water from leaking from between the flange portion 81 of the EGR valve 80 and the housing portion 31.

  Also in the present embodiment, one of the connection holes 45 and 46 of the housing portion 31 is formed to have a larger diameter than the other, and the EGR cooler core 33 is formed with the larger diameter side of the connection holes 45 and 46 as an inlet. The EGR cooler core 33 is assembled into the housing 31 by fixing the EGR cooler core housing 59 and the EGR valve 80 and inserting the assembly having the seal member 63 attached thereto.

  In FIG. 6, φb, which is the diameter of the connection hole 46, is formed larger than φa, which is the diameter of the connection hole 45, and assembly is performed by inserting the EGR cooler core 33 with the connection hole 46 as an inlet.

  In the present embodiment, the EGR cooler core 33 is inserted into the housing portion 31 by inserting the assembly formed by fixing the EGR cooler core housing 59 and the EGR valve 80 to the EGR cooler core 33 and mounting the seal member 63 into the connection hole 46. Since the assembly of 33 is performed, the assembly including the EGR valve 80 can be assembled to the housing portion 31 at a time, and the assembly workability can be improved.

Further, a diameter of the connecting hole 46 .phi.b, because they are larger than a diameter of the connecting hole 45 .phi.a, improved reliability of the assembly work of the EGR cooler core 33 into the housing portion 31, resulting in the seal Improved performance robustness.

  Further, since the EGR valve 80 is exposed to the cooling water passing through the housing portion 31, the EGR valve 80 can be prevented from being heated at a high temperature during the operation of the engine 10, and the EGR valve 80 can be frozen at a low temperature. Can be prevented.

  As described above, in the present embodiment, instead of the EGR pipe flange 52 of the EGR pipe 37, the EGR cooler core 33 is connected to the upstream side and the downstream side of the EGR cooler core 33 and passes through the internal passage 34. The flow rate of the exhaust gas is variably controlled, and an EGR valve 80 that partially contacts the cooling water that passes through the cooling water outlet passage 30 is provided. The seal member 63 is provided on the other upstream side and downstream side of the EGR cooler core 33. And an elastic gas seal portion 55a.

  With this configuration, during operation of the engine 10, the EGR valve 80 can be cooled with the cooling water passing through the cooling water outlet passage 30, and the EGR valve 80 can be prevented from freezing at low temperatures.

(Third embodiment)
FIGS. 7-14 has shown the structure of the principal part of the exhaust-air-cooling apparatus based on the 3rd Embodiment of this invention.

  As shown in FIG. 7, in the present embodiment, a head rear housing 32 having a separate structure from the cylinder head 12 is used as a casing of the EGR cooler 23. As shown in FIGS. 7, 8, and 9, the head rear housing 32 includes an upper divided body 32a and a lower divided body 32b that can divide the inner peripheral wall surfaces of the connection holes 45 and 46, respectively. ing.

  Since the EGR cooler core 33 is accommodated in the space that passes through the connection holes 45 and 46, the head rear housing 32 is divided into an upper divided body 32a and a lower divided body 32b at the center of the EGR cooler core 33. Yes.

  The upper divided body 32a and the lower divided body 32b are respectively fixed to the head rear housing 32 by bolts. Further, the mating surface (the surface indicated by hatching in FIG. 9) of the upper divided body 32a and the lower divided body 32b is sealed with FIPG (Formed in Place Gasket) or the like.

  The head rear housing 32 has a water outlet 72 in the same manner as the housing portion 31 of FIGS. 3 and 6, and the dividing surface of the upper divided body 32 a and the lower divided body 32 b is the inner peripheral wall surface of the water outlet 72. Also passes.

  Since the head rear housing 32 has a divided structure including the upper divided body 32a and the lower divided body 32b, the EGR cooler core 33 can be assembled into the head rear housing 32 from the connection hole 45 or the connection hole 46. Can be performed in a state where the upper divided body 32a and the lower divided body 32b are divided.

  Therefore, as shown in FIG. 10A, the enlarged EGR cooler core 33, that is, the EGR cooler core 33 larger in diameter than the connection holes 45 and 46, is accommodated in the head rear housing 32, or FIG. As shown, the curved EGR cooler core 33 can be accommodated in the head rear housing 32.

  Therefore, the surface area of the EGR cooler core 33 can be increased by expanding or bending the EGR cooler core 33, and the cooling capacity of the EGR cooler 23 can be improved.

  Further, since it is not necessary to assemble the EGR cooler core 33 into the head rear housing 32 through the connection holes 45 and 46, the diameter φa of the connection hole 45 and the diameter φb of the connection hole 46 are the same diameter (φa = φb). Therefore, the EGR cooler core housing 59 and the EGR cooler core housing 60 that are respectively provided at both ends of the EGR cooler core 33 can be formed as common parts having the same shape.

  Similarly, the seal member 63 and the seal member 64 that are respectively disposed at both end portions of the EGR cooler core 33 can be formed as common parts having the same shape. Furthermore, the EGR pipe gasket 55 and the EGR pipe gasket 56 that are respectively disposed at positions corresponding to both ends of the EGR cooler core 33 can be formed as common parts having the same shape.

  Further, as shown in FIG. 11A, the elastic gas seal portion 56a of the EGR pipe gasket 56 and the EGR cooler core housing 60 can be integrated by welding or the like. In FIG. 11A, the elastic gas seal portion 56 a of the EGR pipe gasket 56 and the EGR cooler core housing 60 are joined at a weld portion 65.

  Further, in place of the elastic gas seal portion 56a of the EGR pipe gasket 56 and the EGR cooler core housing 60, as shown in FIG. 11 (b), the EGR cooler core gasket housing 66 integrated by constituting them from the same member. Can be used.

Therefore, by integrating the EGR pipe gasket 56 and the EGR cooler core housing 60, since it is unnecessary to exhaust gas passing through the EGR cooler core housing 60 is leaked to the seal member 63 side, a sealing member 64 hot It can be completely cut off from the exhaust gas.

  As shown in FIGS. 12 to 14, a block side housing 38 disposed on the side surface of the cylinder block 11 is used as the casing of the EGR cooler 23, and this block side housing 38 is used as the head shown in FIGS. Similarly to the rear housing 32, the upper divided body 38a and the lower divided body 38b may be used.

  The cylinder block 11 is provided with a water jacket 11c for cooling the cylinder 11e, a head bolt hole 11d for coupling to the cylinder head 12, and an oil dropping hole 11f for allowing oil to flow down from the cylinder head 12.

  Further, the cylinder block 11 is provided with a water jacket opening 11a communicating with the water jacket 11c and a bolt hole seating surface 11b formed around the water jacket opening 11a.

  The block side surface housing 38 composed of the upper divided body 38a and the lower divided body 38b is fixed to the water jacket opening 11a by bolt fastening. The block side housing 38 has connection holes 45 and 46 and a water outlet 72 as in the head rear housing 32 of FIGS.

  The cooling water discharged from the water outlet 72 is returned to a water pump (not shown) through an external pipe made of metal or rubber. The block side housing 38 has EGR pipes 36 and 37 as in the head rear housing 32 of FIGS.

  As shown in FIGS. 12 to 14, even when the block side housing 38 having the divided structure is used as the casing of the EGR cooler 23, the same effects as when the head rear housing 32 having the divided structure shown in FIGS. 7 to 9 is used. Have.

  Further, as shown in FIGS. 12 to 14, when the block side housing 38 having a divided structure is used as the casing of the EGR cooler 23, the handling of the EGR pipes 36 and 37 is slightly complicated. Since the block side housing 38 can be installed in the water jacket opening 11a, the degree of freedom in layout of the block side housing 38 is increased.

  As described above, in the present embodiment, the head rear housing 32 has the upstream and downstream connection holes 45 and 46 located on the upstream side and the downstream side of the internal passage 34 of the EGR cooler core 33, and the upstream side In addition, the inner peripheral wall surfaces of the connection holes 45 and 46 on the downstream side are each composed of an upper divided body 32a and a lower divided body 32b that can be divided into a plurality of pieces, and the block side housing 38 is similarly divided into the upper divided body 38a and the lower divided body. It is comprised with the body 38b.

  With this configuration, even if the shape of the EGR cooler core 33 is curved or enlarged in order to increase the contact area with the cooling water, the EGR cooler core 33 is separated from the head rear housing 32 in a state where the head rear housing 32 and the block side housing 38 are divided. Since it can be assembled in the block side housing 38, the cooling capacity can be increased.

(Fourth embodiment)
FIGS. 15-17 has shown the structure of the principal part of the exhaust-air-cooling apparatus based on the 4th Embodiment of this invention.

  In the present embodiment, various shapes of the EGR cooler core 33 are illustrated, and the EGR cooler core housings 59 and 60 are changed to match the shape of the EGR cooler core 33, whereby the EGR cooler core 33 and the EGR cooler core housing are changed. 59 and 60 can be joined, and heat exchange between the exhaust gas passing through the EGR cooler core 33 and the cooling water is possible.

  15 (a) and 15 (b), an EGR cooler core 33 includes a cylindrical cylindrical portion 33c constituting the outer periphery of the EGR cooler core 33, and a cross section arranged in a lattice shape inside the cylindrical portion 33c. A plurality of partition portions 33s extending in the direction and spaced apart from each other in a direction perpendicular to the axial direction.

  Each section partitioned by the partition portion 33 s communicates from one side of the EGR cooler core 33 to the other side. Thereby, the inside of the cylindrical portion 33c is partitioned into a plurality of passages having a substantially square cross section by the partition portion 33s.

  The EGR cooler core housings 59 and 60 are respectively joined to both ends of the cylindrical portion 33c by welding or brazing. The cooling water cools the heat of the exhaust gas transmitted from the partition portion 33s to the cylindrical portion 33c when passing outside the cylindrical portion 33c.

  16 (a), 16 (b), 17 (a), and 17 (b), the EGR cooler core 33 is composed of a plurality of tubular portions 33t that are separated from each other in a direction orthogonal to the axial direction. . Moreover, the EGR cooler core housings 59 and 60 have substantially disk-shaped disk parts 59a and 60a having a function of collecting pipes between the ends of the plurality of tubular parts 33t. Both ends of each tubular portion 33t are joined to the disk portions 59a and 60a by welding or brazing, respectively.

  In the configuration shown in FIGS. 16A and 16B, the EGR cooler core 33 has two tubular parts 33t having a rectangular cross section, and these tubular parts 33t are joined to the disk parts 59a and 60a. The portions have a relatively large cross-sectional area and the opposing surfaces are in close contact with each other. Moreover, each tubular part 33t has a relatively narrow cross-sectional area and is separated from each other except at both ends, and a gap between each tubular part 33t serves as a cooling water passage.

  In the configuration shown in FIGS. 17A and 17B, the EGR cooler core 33 has five cylindrical tubular portions 33t, and these tubular portions 33t are separated from each other, and each tubular portion 33t. The space between is a passage for cooling water.

  Thus, in any of the configurations of FIGS. 15 to 17, the EGR cooler core 33 and the EGR cooler core housings 59 and 60 can be joined, and the exhaust gas and the cooling water passing through the EGR cooler core 33 can be used. Heat exchange with is possible.

  As described above, the present invention can improve the robustness of the sealing performance by blocking the sealing member from the high-temperature exhaust gas, and can suppress the EGR cooler core shake due to thermal expansion and engine vibration. This is advantageous in that it is useful for general exhaust cooling devices provided in an exhaust gas recirculation device for a vehicle internal combustion engine.

  DESCRIPTION OF SYMBOLS 10 ... Engine (internal combustion engine), 11 ... Cylinder block, 12 ... Cylinder head, 13 ... Intake manifold, 14 ... Exhaust manifold, 20 ... EGR device, 21 ... EGR gas passage, 23 ... EGR cooler (exhaust cooling device), 30 ... Cooling water outlet passage (cooling water passage), 31 ... Housing part (housing), 32 ... Head rear housing (housing), 32a ... Upper divided body (housing divided body), 32b ... Lower divided body (housing divided body) 33 ... EGR cooler core, 33a, 33b ... end, 34 ... internal passage, 36, 37 ... EGR pipe, 38 ... block side housing (housing), 38a ... upper divided body (housing divided body), 38b ... lower divided Body (housing divided body), 43, 44 ... Pipe connection, 45, 46 ... Connection hole, 51, 52 ... EGR 55, 56, 57 ... EGR pipe gasket (gasket member), 55a, 56a ... elastic gas seal portion, 59, 60 ... EGR cooler core housing (opposite end portion), 63, 64 ... seal member 72 ... Water outlet, 80 ... EGR valve

Claims (6)

An EGR cooler core having an internal passage for recirculating exhaust gas of an internal combustion engine capable of exhaust gas recirculation to the intake side;
To form a cooling water passage between the EGR cooler core and housing the EGR cooler core inwardly, on at least one side of the upstream and downstream of the EGR cooler core in the reflux direction of the exhaust gas, the EGR A housing having a pipe connection portion in which a connection hole having a hole diameter into which a cooler core can be inserted is formed ;
An exhaust gas cooling device comprising an EGR pipe having a connection end connected to the pipe connection portion of the housing,
The EGR cooler core has an opposing end facing the connection end of the EGR pipe, and the cooling water passage is provided between the outer peripheral side of the opposing end and the inner peripheral wall surface of the connection hole. A seal member for liquid-tight partitioning from the outside of the internal passage and the housing is mounted,
Between the connection end portion of the EGR pipe and the pipe connection portion of the housing, a central portion is formed of an annular member extending into the connection hole, and the internal passage and the inside of the EGR pipe are disposed in the interior of the EGR pipe. A gasket member that hermetically blocks from the outside of the housing is attached,
In the gasket member, a center portion of the annular member abuts against the opposed end portion of the EGR cooler core inside the connection hole, and the opposed end portion of the EGR cooler core and the connected end portion of the EGR pipe An exhaust gas cooling device is provided, wherein an elastic gas seal portion is provided that is elastically compressed between the exhaust gas and the exhaust gas passing through the internal passage from the seal member. In addition to variably controlling the flow rate of the exhaust gas passing through the internal passage connected to the EGR cooler core, instead of the connection end of the EGR pipe, on one side of the upstream side and the downstream side of the EGR cooler core, A part of which includes an EGR valve that contacts cooling water passing through the cooling water passage;
The exhaust cooling device according to claim 1, wherein the seal member and the elastic gas seal portion are disposed on the upstream side and the downstream side of the EGR cooler core. Said housing, said upstream and located upstream and downstream of the inner passage and having the connection hole on the downstream side, a plurality of inner peripheral wall surface of the connecting hole of the upstream and downstream sides respectively of the EGR cooler core The exhaust cooling device according to claim 1, wherein the exhaust cooling device is configured by a plurality of divided housing parts.   The exhaust cooling device according to any one of claims 1 to 3, wherein the seal member includes a material having rubber elasticity.   The elastic gas seal portion of the gasket member is formed in a bellows shape that can expand and contract in a direction in which the opposed end portion of the EGR cooler core and the connecting end portion of the EGR pipe are opposed to each other. The exhaust cooling device according to any one of claims 1 to 4. The opposed end portion of the EGR cooler core has an annular convex shape that protrudes radially outward from a main body portion of the EGR cooler core,
The elastic gas seal portion of the gasket member is compressed between one side surface of the annular convex opposing end portion and the connection end portion of the EGR pipe. The exhaust cooling device according to any one of items 5 to 6.

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