JP2015048814A - Intake manifold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that condensed water of EGR gas is accumulated in a collector.SOLUTION: In an intake manifold 10 having such a wound shape that plural branch parts 12 surrounds the periphery of a collector 11, a lowest point part 20 positioned vertically lowermost in an on-vehicle state is set in the collector 11. A communication path 21 communicating between the lowest point part 20 of the collector and the branch part 12 positioned on the vertically downward side of the lowest point part is provided. Moisture generated in the collector 11 through the communication path 21 is guided to the branch part 12.

Description

  The present invention relates to an improvement of an intake manifold that is suitably used for an internal combustion engine.

  As described in Patent Document 1, in an internal combustion engine including an EGR device that recirculates a part of exhaust gas from an exhaust passage to an intake passage, EGR gas introduced into a collector of an intake manifold is cooled and condensed. There is a problem that it continues to accumulate in the collector as condensed water.

JP 2009-66819 A

If such condensed water continues to accumulate in the collector and is dried, acidic substances remain, and the pH value is acidified, which may cause deterioration of the intake manifold made of synthetic resin.

  In particular, in the case of a so-called wound intake manifold that is curved so that the branch portion surrounds the collector, the inside of the collector is hardly affected by intake pulsation and negative pressure, and the condensed water generated in the collector is It cannot be efficiently guided to the combustion chamber of the cylinder, and moisture tends to remain in the collector.

  This invention is made | formed in view of such a situation, and makes it the main objective to prevent that water | moisture content, such as condensed water, continues collecting in a collector.

  Accordingly, the present invention provides an intake manifold that guides intake air from the collector to the intake port of each cylinder through a plurality of branch portions, and sets the lowest point portion that is positioned at the lowest position in the vehicle mounted state on the collector. A communication passage that communicates the lowermost point portion with the branch portion positioned vertically below the lowermost point portion, and the moisture generated in the collector is guided to the branch portion through the communication passage. It is configured.

  According to the present invention, the moisture in the collector can be collected at the lowest point portion, and this moisture can be guided to the branch portion through the communication path, so that moisture does not continue to accumulate in the collector, and the intake caused by this moisture can be prevented. Manifold deterioration and the like can be suppressed.

The disassembled perspective view which shows the intake manifold which concerns on 1st Example of this invention. The disassembled perspective view which similarly shows the said intake manifold. Sectional drawing which shows the said intake manifold. Sectional drawing which similarly shows the said intake manifold. The mating surface part before joining in which a communicating path is formed is shown, (A) is a 2nd resin member, (B) is a perspective view of a 3rd resin member. The block diagram which shows typically the mating surface part after joining in which a communicating path is formed. (A) is the comparative example which formed the welding part perpendicular | vertical to the channel | pass longitudinal direction, (B) is explanatory drawing which shows the present Example which formed the welding part in parallel with the channel | path longitudinal direction. The block diagram which shows typically the mating surface part after joining in which the communicating path of the intake manifold which concerns on 2nd Example of this invention is formed.

  Hereinafter, the present invention will be described with reference to illustrated embodiments. 1 to 4 show an intake manifold 10 applied to a four-cylinder internal combustion engine according to a first embodiment of the present invention.

  The intake manifold 10 includes a branch pipe-shaped intake passage that guides intake air from one collector 11 to the intake ports of the respective cylinders via four branch portions 12 corresponding to four # 1 to # 4 cylinders. The four branch portions 12 arranged in parallel have a so-called wound shape in which the collector 11 is curved so as to surround the entire circumference of the collector 11.

  As shown in FIGS. 1 and 2, the intake manifold 10 is configured by joining four resin parts 13 to 16 made of synthetic resin to each other by vibration welding in consideration of moldability at the time of manufacture. 2, the left half of the branch portion 12 is mainly formed by the first resin component 13 and the second resin component 14 on the left side of FIG. 2, and the third resin component 15 and the fourth resin component 16 on the right side of FIG. The right half of the branch part 12 is mainly formed, and the collector 11 is mainly formed by the second resin part 14 and the third resin part 15 closer to the center.

  The collector 11 is located at substantially the center of the intake manifold 10 and has a flat box shape with a predetermined volume, and an EGR passage for returning a part of the exhaust gas into the collector 11 in the vicinity of the upstream opening flange portion 17. One end of 18 is opened. As shown in FIG. 1, an EGR valve mounting portion 19 for adjusting the amount of EGR gas flowing through the EGR passage 18 is provided in the vicinity of the opening flange portion 17.

  In the present embodiment, the collector 11 is set with the lowest point portion 20 positioned in the vertically downward direction in the vehicle-mounted state. 3 and 4 show the posture of the intake manifold 10 in a vehicle-mounted state, and the arrow P is the vertical direction. As shown in FIG. 3, the bottom surface of the collector 11 faces downward with the lowermost point portion 20 as the lower end in a cross section orthogonal to the cylinder row direction as shown in FIG. 4, and the bottom surface of the collector 11 is set to a downwardly convex shape with the lowest point 20 as the lower end in the cross section along the cylinder row direction as shown in FIG. 4. ing. Further, as shown in FIG. 4, the lowest point portion 20 is set in the vicinity of the upstream opening flange portion 17 and immediately downstream of the opening portion of the EGR passage 18.

  And the communication path 21 which connects the lowest point part 20 of this collector 11 and the branch part 12 located in the vertically lower part of this lowest point part 20 is formed. In this embodiment, since the branch part 12 of the # 1 cylinder is located below the lowest point part 20, the branch part 12 of the # 1 cylinder and the lowest point part 20 of the collector 11 are communicated with each other. 21 for communication and connection.

  In this embodiment, since the collector 11 and the surrounding branch portion 12 are disposed relatively apart from each other, reinforcing ribs 22 are appropriately bridged between the two.

  The communication path 21 is formed along the mating surface portion 23 where the second resin member 14 and the third resin member 15 that mainly form the collector 11 are joined together by vibration welding. 5 and 6 show details of the mating surface portion 23. FIG. 5 shows a state before joining and FIG. 6 shows a state after joining. Two first welding ribs 24 are formed on the second resin member 14 at a predetermined distance, and similarly, two second welding ribs 25 are formed on the third resin member 15 at a predetermined distance. Then, the tips of the first welding rib 24 and the second welding rib 25 are joined to each other by vibration welding at the welding portion 26.

  On both sides of the welded portion 26, burr pool portions 27 are formed as spaces for receiving burrs generated during welding. That is, the second resin member 14 is provided with a thick inner projection 28 between the two welded portions 26 so as to form a burr pool portion 27 between the welded portions 26 and each welded portion 26. A pair of outer projections 29 are provided on the outer side of the first projection. After the vibration welding, a predetermined welding clearance 31 is set between the tips of the inner protrusion 28 and the outer protrusion 29 and the facing surface of the third resin member 15 facing the inner protrusion 28 and the outer protrusion 29.

  In this embodiment, the communication path 21 is recessed in a semicircular cross section on the facing surface of the third resin member 15 facing the inner protrusion 28. Here, as shown in FIG. 2, since the third resin member 15 is located obliquely below the second resin member 14 in the on-vehicle state, the communication path 21 is located vertically below the welding clearance 31. Will be placed.

  As described above, in the present embodiment, the lowest point portion 20 that is positioned at the lowermost vertical position in the vehicle-mounted state is set in the collector 11, and the lowermost point portion 20 of the collector 11 and the lowermost point portion 20 are positioned below the lowermost point portion 20. Since the communication passage 21 that communicates with the branch portion 12 is provided, the condensed water (moisture) of the EGR gas generated in the collector 11 is collected at the lowermost point portion 20, and is passed through the communication passage 21 to the branch portion 12. And can be reliably guided by natural fall. Since the branch section 12 is closer to the combustion chamber than the collector 11 and is easily affected by intake pulsation and negative pressure, the condensed water supplied to the branch section 12 is promptly guided to the combustion chamber and evaporated with combustion. The For this reason, it is possible to prevent the condensed water from continuing to accumulate in the collector 11 while the branch portion 12 is the wound intake manifold 10 surrounding the collector 11.

  Further, since the communication path 21 is formed along the mating surface portion 23 where the plurality of resin parts 13 to 16 constituting the intake manifold 10 are joined, the number of parts and man-hours for forming the communication path 21 are reduced. There is no additional cost and the productivity is extremely good.

    FIG. 7A shows a comparative example in which a weld portion 26A is provided perpendicular to the passage longitudinal direction L of the communication passage 21A through which EGR condensed water flows. In such a comparative example, when moisture enters the burr pool part or the weld part 26A through the welding clearance, the moisture is difficult to be discharged and the water continues to accumulate. There is a risk of deterioration.

  In contrast, in this embodiment, as shown in FIG. 7B, the welded portion 26 is formed in parallel with the passage longitudinal direction L of the communication passage 21A through which the EGR condensed water flows. The flow of water does not straddle the welded portion 26. Therefore, it is difficult for moisture to enter the welding portion 26, and even if condensed water enters the burr pool portion from the welding clearance, the condensed water flows along the burr pool portion formed in parallel with the communication path 21. Therefore, the welded portion 26 is unlikely to deteriorate.

  Furthermore, in this embodiment, as shown in FIG. 6, since the communication path 21 is formed below the welding clearance, even if condensed water accumulates near the lower surface of the communication path 21, this condensed water is welded. Intrusion from the clearance 31 into the burr pool 27 can be more reliably suppressed.

  FIG. 8 shows a second embodiment of the present invention. Note that the same reference numerals are assigned to the same components as those in the first embodiment, and redundant description will be omitted as appropriate. In this second embodiment, two inner projections 28B are provided between the two welding portions 26, and each inner projection 28B forms a burr pool portion 27 between the corresponding welding portions 26. Yes. A communication path 21B is formed between the two inner protrusions 28B. That is, in the second embodiment, the communication path 21B is formed by using the two inner protrusions 28B, and the communication path 21 is recessed in the third resin component 15 as in the first embodiment described above. Compared to the case, the part shape is simplified, and a large passage cross-sectional area of the communication passage 21B can be secured. However, in the case of the second embodiment, the welding clearance 31B between the tip of the inner protrusion 28B and the facing surface of the third resin component 15 is positioned vertically below the communication path 21B. In comparison, the risk that condensed water enters the burr pool portion 27 from the welding clearance 31B is increased.

  As described above, the present invention has been described based on the specific embodiments. However, the present invention is not limited to the above-described embodiments, and includes various modifications and changes. For example, as the moisture generated in the collector 11, in the above embodiment, condensed water by EGR gas is taken as an example, but the structure of the present invention is also effective for moisture generated by blow-by gas.

DESCRIPTION OF SYMBOLS 10 ... Intake manifold 11 ... Collector 12 ... Branch part 13-16 ... Resin part 18 ... EGR channel | path 20 ... Bottom point part 21, 21B ... Communication path 23 ... Matching surface part 24, 25 ... Welding rib 26, 26B ... Weld part 27 ... Burr pool part 28, 28B ... Inner protrusion 29 ... Outer protrusion 31, 31B ... Welding clearance

Claims (4)

In the intake manifold that guides intake from the collector to the intake port of each cylinder through multiple branches,
While setting the lowest point part located in the lowermost vertical position in the on-board state in the collector,
A communication path is provided for communicating the lowest point of the collector and the branch located vertically below the lowest point;
An intake manifold configured to guide moisture in the collector to the branch portion through the communication path.   2. The intake manifold according to claim 1, wherein the communication path is formed along a mating surface portion where a plurality of resin parts constituting the intake manifold are joined.   3. The intake manifold according to claim 1, wherein welded portions between the resin parts positioned on both sides of the communication path extend along a longitudinal direction of the communication path. From one of the resin parts joined together between the welded part and the communication path so as to form a burr pool part between the welded part between the resin parts located on both sides of the communication path and the communication path. Protruding part protruding toward the other resin part is provided,
A predetermined welding clearance is ensured between the tip of the projection and the other resin part,
The intake manifold according to any one of claims 1 to 3, wherein the communication path is disposed vertically below the welding clearance in an on-vehicle state.

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