JP2019074027A - EGR gas distributor - Google Patents

Abstract

To warm the entire inner wall of a gas distribution part, without needing excessive electric constitution or energy, from an early stage in engine cold start.SOLUTION: An EGR gas distributor 1 is mounted in an intake manifold 2, and configured to distribute EGR gas into branch pipes 4A-4D of the intake manifold 2. The EGR gas distributor 1 comprises: a gas distribution unit 15 into which EGR gas is introduced, and which is configured to distribute EGR gas to the respective branch pipes 4A-4D; and a heating unit 16 configured to heat the gas distribution unit 15. The gas distribution unit 15 and the heating unit 16 are provided adjacently via a partition wall 17. In the heating unit 16, cooling water of an engine flows for heating the gas distribution unit 15. The gas distribution unit 15 is provided with heat transfer enhancement means of enhancing transfer to a farthest potion 18 farthest from the partition wall 17, for heat transferred from the heating unit 16 to the partition wall 17.SELECTED DRAWING: Figure 5

Description

  The technology disclosed in this specification relates to an EGR gas distributor used by being attached to an intake manifold to distribute EGR gas to a plurality of cylinders of an engine.

  Conventionally, as a technique of this type, for example, an intake manifold described in Patent Document 1 below is known. The intake manifold includes a plurality of intake pipes (branch pipes) for distributing intake air to a plurality of cylinders of the engine, and an EGR chamber (EGR gas distribution unit) for distributing EGR gas to the respective branch pipes. The EGR gas distribution sections are provided to straddle them in a direction crossing them on the upper side of each branch pipe, and are integrally formed with the intake manifold. In addition, a recess is provided on the inner side of the EGR gas distribution unit in which the EGR gas can be retained, and on the outer side thereof, a hot water passage through which engine cooling water (hot water) flows is provided adjacent to the recess. Therefore, part of the EGR gas flowing into the EGR gas distribution unit is retained in the recess. Thereby, heat exchange is performed between the stagnant EGR gas and the hot water flowing in the hot water passage, and the EGR gas in the EGR gas distribution unit is efficiently kept warm, and the generation of condensed water in the EGR gas distribution unit or freezing To reduce the

JP, 2005-155448, A

  By the way, in the intake manifold described in Patent Document 1, although the EGR gas in the EGR gas distribution unit can be efficiently kept warm by the warm water, the EGR gas can not be warmed from an earlier stage at the cold start of the engine, It was difficult to start EGR. Immediately after the start of the cold start, the engine cooling water does not become appropriate warm water, and the EGR gas distribution unit can not be warmed. In addition, since the contact area between the EGR gas distribution unit and the hot water passage is only a part of the total surface area of the EGR gas distribution unit, it takes time to transfer the heat of the hot water to the entire EGR gas distribution unit. . Here, in order to start EGR earlier than the time of cold start, it is necessary to suppress the generation of condensed water in the EGR gas distribution unit. For that purpose, the inner wall of the EGR gas distribution unit is cold started It needs to be warmed earlier. Here, it is conceivable to heat the inner wall of the EGR gas distribution unit from an earlier stage of cold start using an electric heater, but in that case, extra electrical configuration and energy are required, Configuration becomes complicated.

  This disclosed technology has been made in view of the above circumstances, and the purpose thereof is to provide a gas distribution unit without requiring extra electric configuration or energy from an earlier stage of cold start of the engine. It is an object of the present invention to provide an EGR gas distributor which makes it possible to warm the entire inner wall of the

  In order to achieve the above object, the technique according to claim 1 is an appendage attached to an intake manifold, which is an EGR gas distributor that distributes EGR gas to each of a plurality of branch pipes constituting the intake manifold. A gas distribution unit for introducing the EGR gas and distributing the EGR gas to each of the plurality of branch pipes, a heating unit for heating the gas distribution unit, the gas distribution unit, and the heating unit via the partition walls Adjacent to each other, the heating part is configured to flow engine cooling water to heat the gas distribution part, and is provided in the gas distribution part, and the heat transmitted from the heating part to the partition wall is a partition wall And heat transfer promoting means for promoting the transfer to the farthest part farthest from the above.

  According to the configuration of the above technology, the gas distribution unit is attached to an intake manifold attached to the engine. In this mounted state, at the time of cold start of the engine, cooling water (hot water) flows through the heating portion. Further, the EGR gas introduced into the gas distribution unit is distributed from the gas distribution unit to the plurality of branch pipes. Here, since the gas distribution unit and the heating unit are provided adjacent to each other via the partition, the heat of the hot water flowing through the heating unit is transmitted to the partition. Further, the heat transferred to the partition wall is transferred from the partition wall to the EGR gas in the gas distribution unit, and transferred to the farthest part farthest from the partition wall. At this time, the heat transfer to the farthest part is promoted by the heat transfer promoting means. Accordingly, the entire inner wall of the gas distribution unit is quickly warmed by the heat transmitted to the partition wall.

  In order to achieve the above object, according to the technology of claim 2, in the technology of claim 1, the gas distribution unit includes a chamber case having a gas chamber into which an EGR gas is introduced, and a chamber case. A gas introduction pipe for introducing EGR gas, and a plurality of gas distribution pipes branched from the chamber case for distributing the EGR gas from the gas chamber to the plurality of branch pipes, and the heat transfer promoting means is the chamber case The cross-sectional shape of the peripheral wall formed by the peripheral wall of the chamber case cut in a plane orthogonal to the longitudinal direction of the chamber case is smoothly continuous from the partition wall toward the farthest portion, and the change of the shape is bent convexly I assume.

  According to the configuration of the above technology, in addition to the function of the technology according to claim 1, the heat transfer promoting means is constituted by the peripheral wall of the chamber case, and a cross section of the peripheral wall obtained by cutting the chamber case in a plane orthogonal to its longitudinal direction. The shape is smoothly continuous from the partition to the farthest part, and the transition part of the shape is convexly curved. Therefore, since the turning portion of the shape of the peripheral wall is bent in a convex manner, the length on the peripheral wall from the partition to the farthest portion is relatively shorter than in the case where the turning portion is not bent convexly, and the farthest portion from the partition Heat is easily transmitted to

  In order to achieve the above object, according to the third aspect of the present invention, in the first aspect, the gas distribution unit includes a chamber case having a gas chamber into which an EGR gas is introduced, and a chamber case. A gas introduction pipe for introducing EGR gas, and a plurality of gas distribution pipes branched from the chamber case for distributing the EGR gas from the gas chamber to the plurality of branch pipes, and the heat transfer promoting means includes the gas chamber It is intended that the heat transfer rib is disposed in the heat transfer rib which connects the partition wall and the farthest part at the shortest distance.

  According to the configuration of the above technology, in addition to the function of the technology according to claim 1, the heat transfer promoting means is disposed in the gas chamber, and the heat transfer rib which connects the partition wall and the farthest part in the shortest distance. It consists of Therefore, heat is easily transmitted from the partition wall to the farthest site through the heat transfer rib.

  In order to achieve the above object, according to a fourth aspect of the present invention, in the second or third aspect, the chamber case of the gas distribution unit is formed in a laterally elongated shape so as to cross a plurality of branch pipes. The tube is disposed such that the axial direction is orthogonal to the longitudinal direction of the chamber case, and the EGR gas introduced into the gas chamber is disposed so that it hits near the farthest portion of the chamber case. I assume.

  According to the configuration of the above technology, in addition to the operation of the technology according to the second or third aspect, the axial direction of the gas introduction pipe is arranged to be orthogonal to the longitudinal direction of the chamber case. In addition, the gas introduction pipe is disposed such that the EGR gas introduced into the gas chamber strikes the vicinity of the farthest portion of the chamber case. Therefore, the farthest part is positively warmed by the heat of the EGR gas.

  In order to achieve the above object, according to the technique described in claim 5, in the technique according to any one of claims 2 to 4, in the cross-sectional shape obtained by cutting the chamber case in a plane orthogonal to its longitudinal direction, the partition wall It is intended to be curved.

  According to the configuration of the above technology, in addition to the function of the technology according to any one of claims 2 to 4, in the cross sectional shape, since the partition wall is curved, the surface area is increased, and the heat transmitted from the heating portion to the partition is Increase.

  According to the technique of claim 1, heating the entire inner wall of the gas distribution unit from an earlier stage of cold start of the engine without requiring any extra electric configuration and energy such as an electric heater. Can.

  According to the technology described in claim 2, heating the entire inner wall of the gas distribution unit from an earlier stage at cold start of the engine without requiring extra electric configuration and energy such as an electric heater. Can.

  According to the technique of claim 3, heating the entire inner wall of the gas distribution unit from an earlier stage of cold start of the engine without requiring any extra electric configuration or energy such as an electric heater. Can.

  According to the technology of claim 4, in addition to the effects of the technology of claim 2 or 3, the inner wall of the gas distribution unit can be further warmed by the heat of the EGR gas.

  According to the technology of claim 5, in addition to the effect of the technology according to any one of claims 2 to 4, it is possible to transfer more heat of the hot water of the heating section to the inner wall of the gas distribution section.

The perspective view which concerns on 1st Embodiment and shows an EGR gas distributor. FIG. 2 is a perspective view of an EGR gas distributor attached to an intake manifold according to the first embodiment. FIG. 3 is a perspective view according to the first embodiment, showing the EGR gas distributor and the intake manifold of FIG. 2 by cutting the EGR gas distributor in a vertical direction along a longitudinal direction (in a vertical plane passing through line A-A); FIG. 3 is a perspective view according to the first embodiment, showing the EGR gas distributor and the intake manifold of FIG. 2 by cutting the EGR gas distributor horizontally (along a line B-B) along the longitudinal direction. FIG. 3 is a perspective view showing the EGR gas distributor and the intake manifold of FIG. 2 in a vertical plane perpendicular to the longitudinal direction of the EGR gas distributor at the position of the gas introduction pipe according to the first embodiment; FIG. 3 is a perspective view showing the EGR gas distributor and the intake manifold of FIG. 2 in a vertical plane perpendicular to the longitudinal direction of the EGR gas distributor at the position of the gas distribution pipe according to the first embodiment; FIG. 6 is an enlarged cross-sectional view of a cross section of the EGR gas distributor and the intake manifold of FIG. 5 according to the first embodiment. FIG. 7 is an enlarged cross-sectional view of the EGR gas distributor and the intake manifold of FIG. 6 according to the first embodiment; Sectional drawing which concerns on 2nd Embodiment and shows the cut surface of EGR gas distributor and an intake manifold according to FIG. Sectional drawing which concerns on 2nd Embodiment and shows the cut surface of EGR gas distributor and an intake manifold according to FIG. Sectional drawing which concerns on 3rd Embodiment and shows the cut surface of EGR gas distributor and an intake manifold according to FIG. Sectional drawing which concerns on 3rd Embodiment and shows the cut surface of EGR gas distributor and an intake manifold according to FIG. The table | surface which compares and shows the difference in the cross-sectional shape of a gas distribution part, and differences, such as a heat-transfer effect. A table showing the continuation of FIG. The schematic diagram which shows the object of a theoretical formula.

First Embodiment
Hereinafter, a first embodiment of the EGR gas distributor will be described in detail with reference to the drawings.

[Relationship between EGR gas distributor and intake manifold]
FIG. 1 shows the EGR gas distributor 1 in a perspective view. FIG. 2 is a perspective view of the EGR gas distributor 1 attached to the intake manifold 2. FIG. 3 is a perspective view of the EGR gas distributor 1 and the intake manifold 2 of FIG. 2 cut in the vertical direction along the longitudinal direction of the EGR gas distributor 1 (in a vertical plane passing along the line A-A). FIG. 4 is a perspective view in which the EGR gas distributor 1 and the intake manifold 2 of FIG. 2 are cut horizontally (in a horizontal plane passing along the line B-B) along the longitudinal direction of the EGR gas distributor 1. The EGR gas distributor 1 is arranged as shown in FIGS. 1 to 4 and mounted on the intake manifold 2 attached to the engine, and the upper and lower sides thereof are as shown in FIGS. 1 to 4. As is well known, the intake manifold 2 includes a surge tank 3, a plurality of branch pipes 4A, 4B, 4C, 4D branched from the surge tank 3, and an outlet flange for connecting the branch pipes 4A to 4D to the engine. And 5. In this embodiment, the intake manifold 2 has four branch pipes 4A to 4D corresponding to a four-cylinder engine, and is formed of resin. The EGR gas distributor 1 is used by being attached to the intake manifold 2 in order to distribute the EGR gas to each of the branch pipes 4A to 4D of the intake manifold 2.

[About the outline of the EGR gas distributor]
As shown in FIG. 1, the external appearance of the EGR gas distributor 1 is a gas introduction pipe 11 that protrudes obliquely upward from the upper surface center, and a plurality of gas distribution pipes 12A, 12B, 12C that project obliquely downward from the front. , 12D and pipe joints 13A, 13B respectively projecting from the left and right side surfaces. The EGR gas distributor 1 can be made of a resin material having a good thermal conductivity. For example, by mixing carbon powder with a resin material, a resin material with good thermal conductivity can be configured. FIG. 5 is a perspective view of the EGR gas distributor 1 and the intake manifold 2 of FIG. 2 cut along a vertical plane perpendicular to the longitudinal direction of the EGR gas distributor 1 at the position of the gas introduction pipe 11. FIG. 6 is a perspective view of the EGR gas distributor 1 and the intake manifold 2 of FIG. 2 cut along a vertical plane orthogonal to the longitudinal direction of the EGR gas distributor 1 at the position of the gas distribution pipe 12C. FIG. 7 shows an enlarged cross-sectional view of the cut surfaces of the EGR gas distributor 1 and the intake manifold 2 of FIG. FIG. 8 shows an enlarged cross-sectional view of the cut surfaces of the EGR gas distributor 1 and the intake manifold 2 of FIG. As shown in FIGS. 4 to 8, the EGR gas distributor 1 is provided with a gas distribution unit 15 for distributing the EGR gas to each of the plurality of branch pipes 4A to 4D of the intake manifold 2, into which the EGR gas is introduced. And a heating unit 16 for heating the gas distribution unit 15. The gas distribution unit 15 and the heating unit 16 are provided adjacent to each other via the partition wall 17. In this embodiment, the partition wall 17 is convexly curved toward the heating portion 16 in a cross-sectional shape in which a chamber case 32 described later is cut along a vertical plane perpendicular to the longitudinal direction. In this embodiment, the number (four) of the gas distribution pipes 12A to 12D and the position (center) of the gas introduction pipe 11 are an example.

[About heating part]
In order to heat the gas distribution unit 15, the heating unit 16 is configured so that cooling water (hot water) of the engine flows. That is, heating unit 16 includes passage case 22 having water passage 21 through which engine cooling water (hot water) flows, and pipe fittings 13A and 13B formed on the left and right ends of passage case 22. As shown in FIGS. 7 and 8, in this embodiment, the passage case 22 has a substantially U-shaped cross-sectional shape having a semicircular portion and a straight portion. In this embodiment, this cross-sectional shape is substantially the same at any position in the longitudinal direction of the passage case 22.

[About gas distribution unit]
The gas distribution unit 15 is branched from a chamber case 32 having a gas chamber 31 into which the EGR gas is introduced, the above-described gas introduction pipe 11 for introducing the EGR gas into the chamber case 32, and the chamber case 32. The plurality of gas distribution pipes 12A to 12D described above for distributing the EGR gas from the gas chamber 31 to the branch pipes 4A to 4D are provided. As shown in FIG. 8, in this embodiment, the gas distribution pipes 12A to 12D are opened toward the outlets of the corresponding branch pipes 4A to 4D. As shown in FIGS. 7 and 8, in this embodiment, both the chamber case 32 and the partition 17 have an arc cross-sectional shape, and when the chamber case 32 and the partition 17 are combined, they have a substantially circular cross-sectional shape. Here, the gas distribution unit 15 is provided with a plurality of heat transfer promoting means in order to promote the transfer of heat transferred from the heating unit 16 to the partition 17 to the farthest portion 18 farthest from the partition 17. That is, one of the heat transfer promoting means is constituted by the peripheral wall 32 a of the chamber case 32. In the cross-sectional shape cut along a vertical plane orthogonal to the longitudinal direction of the chamber case 32, the cross-sectional shape of the peripheral wall 32a smoothly continues from the partition wall 17 toward the farthest portion 18, and the change portion of the shape bends convexly That is, a convex arc is formed. The second heat transfer promoting means is formed of a plate-like heat transfer rib 33 which is disposed in the gas chamber 31 and which connects the partition wall 17 and the farthest portion 18 at the shortest distance. The heat transfer rib 33 is disposed at the center of the gas chamber 31 and integrally formed with the partition wall 17 and the peripheral wall 32a. As shown in FIG. 4, the heat transfer rib 33 is formed at a central portion in the longitudinal direction of the chamber case 32 so as to extend about half the longitudinal length of the chamber case 32. In this embodiment, the cross-sectional shapes described above (including the shapes of the peripheral wall 32a and the partition wall 17) are any position in the longitudinal direction of the chamber case 32 except the portions of the gas introduction pipe 11 and the gas distribution pipes 12A to 12D. It is almost the same.

  Furthermore, in this embodiment, as shown in FIG. 7, the chamber case 32 of the gas distribution unit 15 is formed laterally long so as to cross the plurality of branch pipes 4A to 4D of the intake manifold 2. Further, the gas introduction pipe 11 is disposed such that the axial direction thereof is orthogonal to the longitudinal direction of the chamber case 32. Further, as indicated by an arrow Y1 in FIG. 7, the gas introduction pipe 11 is arranged such that the EGR gas introduced into the gas chamber 31 hits the vicinity of the farthest portion 18 in the chamber case 32.

  According to the EGR gas distributor 1 in this embodiment described above, the gas distribution unit 15 is mounted on the intake manifold 2 mounted on the engine. In this mounted state, cooling water (hot water) flows through the heating portion 16 at the time of cold start of the engine. Further, the EGR gas introduced into the gas distribution unit 15 is distributed from the gas distribution unit 15 to the plurality of branch pipes 4A to 4D. Here, since the gas distribution unit 15 and the heating unit 16 are provided adjacent to each other via the partition wall 17, the heat of the hot water flowing through the heating unit 16 is transmitted to the partition wall 17. Further, the heat transferred to the partition wall 17 is transferred toward the farthest portion 18 most distant from the partition wall 17. At this time, the transfer of heat to the farthest site 18 is promoted by the heat transfer promoting means. Therefore, the entire inner wall of the gas distribution unit 15 is quickly warmed by the heat transmitted to the partition wall 17. Therefore, it is possible to warm the entire inner wall of the gas distribution unit 15 from an earlier stage of cold start of the engine without requiring an extra electric configuration such as an electric heater or energy. As a result, generation of condensed water on the inner wall of the gas distribution unit 15 can be suppressed, and EGR can be started from an earlier timing at cold start.

  According to the configuration of this embodiment, another cross section of the heat transfer promoting means is constituted by the peripheral wall 32a of the chamber case 32, and the sectional shape of the peripheral wall 32a obtained by cutting the chamber case 32 in a vertical plane orthogonal to its longitudinal direction is While continuing smoothly from the partition wall 17 to the farthest portion 18, the transition portion of the shape is bent in a convex manner. Therefore, the length of the peripheral wall 32a from the partition wall 17 to the farthest portion 18 is longer than that in the case where the turning portion of the peripheral wall 32a is bent in a convex shape, and the turning portion is not curved convexly Becomes relatively short, and heat is easily transmitted from the partition wall 17 to the farthest portion 18. Also in this sense, the entire inner wall of the gas distribution unit 15 can be warmed from an earlier stage of cold start of the engine without requiring any additional electrical configuration or energy. As a result, generation of condensed water on the inner wall of the gas distribution unit 15 can be suppressed, and EGR can be started from an earlier timing at cold start.

  Further, according to the configuration of this embodiment, the other one of the heat transfer promoting means is disposed in the gas chamber 31 and is provided by the heat transfer rib 33 which connects the partition wall 17 and the farthest portion 18 at the shortest distance. Configured Therefore, heat is easily transferred from the partition wall 17 to the farthest portion 18 through the heat transfer rib 33. Also in this sense, the entire inner wall of the gas distribution unit 15 can be warmed from an earlier stage of cold start of the engine without requiring any additional electrical configuration or energy. As a result, generation of condensed water on the inner wall of the gas distribution unit 15 can be suppressed, and EGR can be started from an earlier timing at cold start.

  Further, according to the configuration of this embodiment, the axial direction of the gas introduction pipe 11 is arranged to be orthogonal to the longitudinal direction of the chamber case 32. Further, the gas introduction pipe 11 is disposed such that the EGR gas introduced into the gas chamber 31 impinges in the vicinity of the farthest portion 18 in the chamber case 32. Therefore, the farthest portion 18 is positively warmed by the heat of the EGR gas. Therefore, the inner wall of the gas distribution unit 15 can be further warmed by the heat of the EGR gas. As a result, generation of condensed water on the inner wall of the gas distribution unit 15 can be suppressed, and EGR can be started from an earlier timing at cold start.

  Further, according to the configuration of this embodiment, the partition wall 17 forms a convex curve (arc) toward the heating portion 16 in a sectional shape obtained by cutting the chamber case 32 in a vertical plane orthogonal to the longitudinal direction thereof. The surface area is increased, and the heat transferred from the heating unit 16 to the partition wall 17 is increased. Therefore, the heat of the hot water of the heating unit 16 can be transmitted to the inner wall of the gas distribution unit 15 more. As a result, generation of condensed water on the inner wall of the gas distribution unit 15 can be suppressed, and EGR can be started from an earlier timing at cold start.

  In the EGR gas distributor 1 of this embodiment, (1) the cross-sectional shape of the peripheral wall 32a of the chamber case 32 forms an arc, (2) between the partition wall 17 and the farthest portion 18 as heat transfer promoting means. Providing a thermal rib 33. In addition, (3) the gas introduction pipe 11 is disposed such that the EGR gas impinges in the vicinity of the farthest portion 18 of the chamber case 32, and (4) the partition 17 has a sectional shape that forms a convex curve toward the heating portion 16. Have. And in this embodiment, the configuration of (1) to (4) described above is against the specific effect that the entire inner wall of the gas distribution unit 15 can be warmed from earlier time at cold start of the engine. It works synergistically. However, if the EGR gas distributor 1 is provided with the configuration (heat transfer acceleration means) of at least (1) or (2) among the configurations of (1) to (4), the above-described unique effects can be obtained. It is thought that it can secure

Second Embodiment
Next, a second embodiment of the EGR gas distributor will be described in detail with reference to the drawings.

  In the following description, constituent elements equivalent to those in the first embodiment are given the same reference numerals and descriptions thereof will be omitted, and in the following, different points will be mainly described.

[About the configuration of the EGR gas distributor]
FIG. 9 shows a cross section of the EGR gas distributor 1 and the intake manifold 2 of this embodiment in a sectional view according to FIG. FIG. 10 shows a cross section of the EGR gas distributor 1 and the intake manifold 2 of this embodiment in a sectional view according to FIG. The EGR gas distributor 1 of this embodiment differs from the first embodiment mainly in the shapes of the gas distribution unit 15 and the heating unit 16. As shown in FIGS. 9 and 10, the heating portion 16 of this embodiment has a rectangular cross-sectional shape. Further, the partition wall 17 of this embodiment has a linear cross-sectional shape, and the peripheral wall 32a of the chamber case 32 of the gas distribution unit 15 has a semi-elliptical cross-sectional shape. That is, the cross-sectional shape of the peripheral wall 32 a of the chamber case 32 is smoothly continued from the partition wall 17 toward the farthest portion 18, and the transition portion of the shape is convexly curved. This configuration constitutes one of the heat transfer promoting means. Also in this embodiment, a plate-like heat transfer rib 33 integrally formed with the partition wall 17 and the peripheral wall 32 a is provided at the center of the gas chamber 31 as a second heat transfer promoting means.

  Therefore, also by the configuration of the EGR gas distributor 1 of this embodiment, substantially the same operation and effect as those of the first embodiment can be obtained. However, in this embodiment, the peripheral wall 32a of the chamber case 32 has a semielliptical cross-sectional shape, which is slightly smaller than the peripheral wall 32a of the first embodiment in which the cross-sectional shape is an arc. Detailed comparison of the heat transfer effect will be described later. Further, in this embodiment, the surface area of the partition wall 17 is smaller than that of the partition wall 17 of the first embodiment in which the partition wall 17 has a linear cross-sectional shape and the cross-sectional shape is curved. Heat transmitted is reduced slightly.

Third Embodiment
Next, a second embodiment of the EGR gas distributor will be described in detail with reference to the drawings.

[About the configuration of the EGR gas distributor]
FIG. 11 shows a cross section of the EGR gas distributor 1 and the intake manifold 2 of this embodiment according to FIG. FIG. 12 shows a cross section of the EGR gas distributor 1 and the intake manifold 2 of this embodiment according to FIG. The EGR gas distributor 1 of this embodiment differs from the configuration of the second embodiment mainly in terms of the shape of the gas distribution unit 15. As shown in FIGS. 11 and 12, the peripheral wall 32 a of the chamber case 32 of the gas distribution unit 15 of this embodiment has a cross-sectional shape of a semi-elliptical circle having a semi-circular portion and a linear portion. That is, the cross-sectional shape of the peripheral wall 32 a of the chamber case 32 is smoothly continued from the partition wall 17 toward the farthest portion 18, and the transition portion of the shape is convexly curved. This configuration constitutes one of the heat transfer promoting means of this embodiment.

  Therefore, also by the configuration of the EGR gas distributor 1 of this embodiment, it is possible to obtain the same operation and effect as the second embodiment. However, in this embodiment, the peripheral wall 32a of the chamber case 32 has a semi-elliptical cross-sectional shape, which is slightly smaller than the peripheral wall 32a of the second embodiment in which the cross-sectional shape is semi-elliptic. Become. Detailed comparison of the heat transfer effect will be described later.

<Comparison of difference in cross-sectional shape of gas distribution unit and difference in heat transfer effect etc.>
Next, differences in the various cross-sectional shapes of the gas distribution unit 15 and differences in the heat transfer effect and the like will be described in comparison. 13 and 14 mainly show a table comparing differences in cross-sectional shape of the gas distribution unit 15 and differences in heat transfer effect and the like. In the tables of FIG. 13 and FIG. 14, “the distance b” from the partition 17 of the gas distribution unit 15 to the farthest region 18 with respect to the difference in cross sectional shape (schematic view) of the gas distribution unit 15 The difference between the “length L” on the peripheral wall up to 18 and the “heat transfer effect” from the partition wall 17 to the farthest portion 18 is shown. In FIG. 13, although the cross-sectional shape of the gas distribution part 15 differs, the cross-sectional shape of the heating part 16 is the same. In FIG. 14, there are two types of cross-sectional shapes of the heating portion 16, which are different from the cross-sectional shape of the heating portion 16 shown in FIG. 13.

  As schematically shown in FIG. 13 and FIG. 14, the shape of the gas distribution unit 15 is “square”, “triangle (isosceles triangle)”, “semi-elliptic” of the second embodiment, “3 of the third embodiment” The case of "a semicircle" and the "arc" of 1st Embodiment are shown. Here, assuming that the height of the heating unit 16 is “a”, the cross-sectional area of the “square” gas distribution unit 15 is “a × a”, and the cross-sectional area is “a × a” otherwise. Set to As shown in FIG. 13, “distance b” is “a” for “square”, “2 × a” for “triangle”, and “(2 × a) / π” for “half-elliptic” In the case of a semi-elliptical circle, it is "a-? / 8 + a / 2". In addition, “Length L” is “1.5 × a” for “square”, “2.06 × a” for “triangle”, and “1.30 × a” for “half-elliptic” In the case of a semi-elliptical circle, it becomes "1.39 x a" and in "arc" it becomes "1.16 x a". And "the heat transfer effect" becomes "-11.5 ° C" in "triangle" and "half-elliptic" if "square" farthest region 18 (temperature "21 ° C") is "0 ° C" It becomes "+ 4.1.degree. C.", and becomes "+ 2.2.degree. C." for "half-long circle" and "+ 6.9.degree. C." Here, the reason that the "heat transfer effect" of the "arc" is the highest is considered to be because the "length L" of the "arc" is the shortest. Therefore, it can be seen that the cross-sectional shape of the peripheral wall of the gas distribution unit 15 has the highest heat transfer effect when it is formed by an arc from the partition wall 17 to the farthest portion 18. The heat transfer effect is high in "semi-elliptic" next to "arc" and then "semi-elliptical".

Here, the difference in the heat transfer effect (the temperature of the farthest portion 18) described above can be determined by the following theoretical formula (F1).
Q = λ / L × A × (θ1−θ2) (F1)
The object of a theoretical formula is shown by a schematic diagram in FIG. FIG. 15 shows a rectangular parallelepiped 40, and the first end face 40a and the second end face 40b have the same shape (square) and the same area. The area is “A”, the length of the rectangular parallelepiped is “L”, the heat amount applied to the first end face 40 a (partition 17) is “Q”, and the temperature of the first end face 40 a (partition 17) at that time is “ The temperature of the θ1 ′ ′ and the second end face 40 b (the farthest portion 18) is “θ2 (θ1> θ2)”. From this theoretical formula (F1), the temperature θ2 of the second end face 40b (the farthest portion 18) with respect to the difference in “length L” can be obtained.

  Note that the disclosed technology is not limited to the above embodiments, and part of the configuration may be changed as appropriate without departing from the scope of the disclosed technology.

  (1) In the above embodiments, the EGR gas distributor 1 is used to distribute the EGR gas to the branch pipes 4A to 4D of the intake manifold 2. However, the EGR gas distributor 1 is not the EGR gas. It can also be used to distribute auxiliary gas (for example, PCV gas etc.) to each branch pipe 4A to 4D of the intake manifold 2.

  (2) In the above embodiments, the heat transfer rib 33 is provided in the gas chamber 31 of the gas distribution unit 15. However, the heat transfer rib 33 can be omitted.

  (3) In the above embodiments, in the gas distribution unit 15, the gas introduction pipe 11 is disposed such that the EGR gas introduced into the gas chamber 31 hits the vicinity of the farthest portion 18 in the chamber case 32. Can be omitted.

  (4) In the above embodiments, the partition 17 between the gas distribution unit 15 and the heating unit 16 is provided in the entire range in the longitudinal direction of the EGR gas distributor 1. It can also be provided in part of the direction.

  The disclosed technology can be used for an EGR device or a PCV device provided in an engine system.

Reference Signs List 1 EGR gas distributor 2 intake manifold 3 surge tank 4A to 4D branch pipe 11 gas introduction pipe 12A to 12D gas distribution pipe 15 gas distribution unit 16 heating unit 17 partition 18 most distant portion 31 gas chamber 32 chamber case 32a peripheral wall 33 heat transfer Rib (heat transfer promotion means)

Claims (5)

An EGR gas distributor, which is an accessory attached to an intake manifold, which distributes EGR gas to each of a plurality of branch pipes constituting the intake manifold,
A gas distribution unit for introducing the EGR gas and distributing the EGR gas to each of the plurality of branch pipes;
A heating unit for heating the gas distribution unit;
The gas distribution unit and the heating unit are provided adjacent to each other via a partition wall, and the heating unit is configured to flow engine cooling water to heat the gas distribution unit.
EGR provided in the gas distribution unit, heat transfer promoting means for promoting the transfer of heat transferred from the heating unit to the partition to the farthest part farthest from the partition Gas distributor. In the EGR gas distributor according to claim 1,
The gas distribution unit includes a chamber case having a gas chamber into which the EGR gas is introduced, a gas introduction pipe for introducing the EGR gas into the chamber case, and a branch from the chamber case, and the gas chamber And a plurality of gas distribution pipes for distributing the EGR gas to the plurality of branch pipes,
The heat transfer promoting means is constituted by the peripheral wall of the chamber case, and the sectional shape of the peripheral wall obtained by cutting the chamber case at a plane orthogonal to the longitudinal direction is smoothly continuous from the partition wall toward the farthest part An EGR gas distributor characterized in that, at the same time, shape change points are convexly curved. In the EGR gas distributor according to claim 1,
The gas distribution unit includes a chamber case having a gas chamber into which the EGR gas is introduced, a gas introduction pipe for introducing the EGR gas into the chamber case, and a branch from the chamber case, and the gas chamber And a plurality of gas distribution pipes for distributing the EGR gas to the plurality of branch pipes,
The EGR gas distributor according to claim 1, wherein the heat transfer promoting means is formed by a heat transfer rib which is disposed in the gas chamber and which connects the partition wall and the farthest part at the shortest distance. In the EGR gas distributor according to claim 2 or 3,
The chamber case of the gas distribution unit is formed to be transverse to cross the plurality of branch pipes, and the gas introduction pipe is disposed such that the axial direction thereof is orthogonal to the longitudinal direction of the chamber case, An EGR gas distributor characterized in that the EGR gas introduced into the gas chamber is disposed in the vicinity of the farthest portion of the chamber case. In the EGR gas distributor according to any one of claims 2 to 4,
An EGR gas distributor characterized in that the partition wall is curved in a cross-sectional shape obtained by cutting the chamber case in a plane orthogonal to the longitudinal direction thereof.

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