JP6639119B2 - Intake manifold for internal combustion engine - Google Patents

Description

  The present invention relates to an intake manifold mounted on a cylinder head in an internal combustion engine for an automobile or the like.

  In an internal combustion engine, intake air is generally sent from a surge tank to a cylinder head via an intake manifold, and there are many structures in which a surge tank and an intake manifold are integrated. In particular, in recent years, many of the air intake manifolds with a surge tank are made of synthetic resin and have a hollow structure formed by overlapping and joining a plurality of members.

  On the other hand, especially in an internal combustion engine for a vehicle, an EGR device that recirculates a part of the exhaust gas to an intake system is widely provided to promote clean exhaust gas and improve fuel efficiency. In this EGR device, exhaust gas (EGR gas) should be evenly distributed to each intake port, and various distribution structures have been proposed.

  For example, in Patent Document 1, in an intake manifold with a surge tank in which a plurality of members are joined, a straight recirculation passage into which EGR gas flows is made to have a posture crossing an intake branch passage (branch pipe), and a start end of the intake branch passage is set. It is disclosed that communication passages disposed near the air passage and communicating with the recirculation passage, the intake branch passages, and the surge tank are provided for each of the intake branch passages.

  In this patent document 1, a part of intake air is guided to each communication passage, so that EGR gas is pushed into each intake branch passage by the intake air. That is, utilizing the fact that the intake air of the surge tank travels straight through the communication passage, the EGR gas is distributed to each intake branch passage along with the flow of the intake air.

On the other hand, in Patent Document 2, an EGR chamber into which EGR gas flows is provided, and an exhaust gas recirculation pipe connected to each intake branch passage is arranged inside the EGR chamber in a bundled state, and It is disclosed that the opening of each exhaust gas recirculation pipe is located on the side opposite to the entrance to the EGR chamber. According to Patent Document 2, since the EGR gas is distributed to each exhaust gas recirculation pipe at a uniform pressure, it can be said that uniform distribution to each intake branch passage can be ensured.

  Further, in Patent Document 3, in a configuration in which an intake branch passage penetrates a spacer plate that is overlapped and fixed to a cylinder head, a main distribution passage that extends long in the direction in which the intake branch passages are arranged is provided on a mating surface of the spacer plate. It is disclosed to provide a branch distribution passage from the main distribution passage toward each intake branch passage.

JP-A-06-167251 JP 2001-207918 A JP 2010-255485 A

  The configuration of Patent Document 1 is expected to have a higher uniformity of distribution of EGR gas as compared with a case where only a branch passage from the recirculation passage to each intake branch passage is provided, but the communication passage is thin and has high flow resistance. It is not only doubtful that the intake air flows into the communication passage at a pressure (negative pressure) enough to push out the EGR gas, but also because the EGR gas is under a positive pressure, the EGR gas is ejected from the communication passage into the surge tank. It is also a concern.

  On the other hand, in Patent Document 2, as described above, since the EGR gas flows into each exhaust gas recirculation pipe evenly, it can be said that the EGR gas can be uniformly distributed to each cylinder. However, it is undeniable that the structure becomes complicated and soot tends to accumulate in the chamber, and it can be said that there is still room for improvement.

  On the other hand, Patent Literature 3 has a simple structure because the EGR gas recirculation passage is formed by using the components of the intake branch passage.

  The present invention has been made in order to improve such a situation, and forming the EGR gas recirculation passage on the mating surface of the members is based on the idea of Patent Document 3 while maintaining the smoothness of the flow of the EGR gas. And the uniformity of distribution.

  In the intake manifold according to the present invention, a plurality of intake branch passages arranged in parallel are formed so as to penetrate the first member and the second member that are overlapped and joined to each other. In the vicinity of the group of the intake branch passages on the mating surface with the two members, one exhaust gas recirculation main passage extending long in the direction in which the intake branch passages are arranged, and branching from the exhaust gas recirculation main passage. A plurality of exhaust gas recirculation branch passages toward the intake branch passage are formed, and the basic configuration is such that EGR gas flows from one end to the other end of the exhaust gas recirculation main passage. .

And in the above basic configuration,
"The exhaust gas recirculation main passage has a smooth continuous surface on the back side opposite to the group of intake branch passages, thereby allowing the EGR gas to flow smoothly from one end to the other end. Along with
The exhaust gas recirculation main passage is provided with one or a plurality of constrictions having a reduced cross-sectional area, thereby forming a plurality of buffer portions for evenly flowing the EGR gas to each intake branch passage. A bag-shaped part into which the exhaust gas flowing from the one end toward the other end goes straight and enters each buffer part, and a bag-shaped part into which the exhaust gas flowing from the one end toward the other end flows backward. And is formed,
Further, the exhaust gas recirculation branch passage branches from the buffer section at a position corresponding to each of the bag-shaped portions so that the EGR gas flowing toward the innermost portion of the bag-shaped portion flows in. "
It is a configuration. Note that the constricted portion can be called a constricted portion.

  As described above, in recent years, a resin intake manifold in which a surge tank is integrated has been generalized, and it is preferable that the present invention be applied to such a type.

In the present invention, since the EGR gas passages (the exhaust gas recirculation main passage and the exhaust gas recirculation branch passage) are formed on the mating surfaces of the components of the intake manifold , the structure is simple and the intake manifold is large. No increase in weight or weight is caused.

  And since the back part of the exhaust gas recirculation main passage is smoothly continuous, the gas flow is smoother than when the exhaust gas recirculation main passage is bent, and the responsiveness of distribution to each intake branch passage is improved. Is also expensive. Therefore, the control performance of the internal combustion engine can be improved.

  Further, by providing a constriction portion in the exhaust gas recirculation main passage and forming a buffer portion, it is easy to uniformly flow the EGR gas into each intake branch passage while ensuring high straightness of the flow of the EGR gas. realizable. In addition, since the flow rate of the EGR gas is not reduced by bending the exhaust gas recirculation main passage but is reduced by the bottleneck effect of the constricted portion, the EGR gas is used to specify the exhaust gas recirculation main passage. It is possible to prevent the portion from strongly hitting the portion, whereby it is possible to prevent or remarkably suppress a part of the intake manifold from being thermally deformed.

Further, EGR gas flowing through the exhaust gas recirculation main passage flows into the bag-like portion is momentum killed in the bag-like unit, flowing into the exhaust gas recirculation branch passage so as to flow back from the bag-like portion. Therefore, the exhaust gas can be supplied to the exhaust gas recirculation branch passage in a stable state.
The shape of the buffer section and the position of the exhaust gas recirculation branch passage can be adjusted according to the actual conditions such as the number of cylinders and the cross-sectional shape of the intake branch passage. However, as in the embodiment, each buffer section is grooved toward the downstream side. When the width (cross-sectional area) is formed to be small, the compatibility between the smooth flow of the EGR gas and the adjustment of the pressure (flow velocity) is excellent, which is preferable.

FIG. 2 is a perspective view of the intake manifold of the first embodiment as viewed from the front facing a cylinder head. It is a front view of an intake manifold. FIG. 3 is a plan view taken along the line III-III of FIG. 2. It is a principal part top view of 2nd Embodiment.

(1). Outline Next, an embodiment of the present invention will be described with reference to the drawings. First, an outline of the intake manifold will be described with reference to FIGS. In the following description, the terms front, rear, left and right are used to specify the direction, and this direction is shown in FIG. That is, the left-right direction is the direction in which the cylinders are arranged (crank axis direction), and the front-back direction is based on the direction facing the cylinder head. In FIGS. 1 and 2, the cylinder head is located behind the paper surface.

  The intake manifold of the present embodiment is made of resin and integrated with a surge tank, and is composed of four members vertically stacked. That is, the upper member 1 is opened downward, the lower member 2 is opened upward, and the upper intermediate member 3 and the lower intermediate member 4 are interposed therebetween. It has a structure.

  The vertically adjacent members are welded (joined) by ultrasonic vibration or high frequency vibration. For this reason, when the joining surfaces of the adjacent members are narrow, a flange is formed to secure the welding area. 1 and 2, parallel oblique lines are displayed on the upper and lower intermediate members 3 and 4 in order to clarify the form and boundaries of the members.

The intake manifold of the present embodiment is a three-cylinder engine. The intake manifold has first to third three intake branch passages 5, 6, and 7 in order from the right. These intake branch passage 5-7, broadly, the mating surfaces of the upper member 1 and the upper intermediate member 3, and are made form the mating surface of the lower member 2 and the lower intermediate member 4. Therefore, the intake branch passages 5, 6, and 7 have a circular shape bent along the periphery of the intake manifold, and the upper portion is straight toward the cylinder head.

  For this reason, when viewed from the side of the intake manifold, each of the intake branch passages 5, 6, and 7 is roughly arranged such that the starting end is located at the rear end of the intake manifold and is open upward, and is directed toward the near side. It bends from top to bottom and bottom to top in a range of about 270, and the horizontal portion at the upper end extends rearward in a tangential posture. Outward bulging portions for forming the intake branch passages 5, 6, 7 are formed in the upper member 1 and the lower member 2.

  Roughly, a surge tank 8 is formed between upper and lower intermediate members 3 and 4. Further, at the front of the intake manifold, the four members 1 to 4 overlap in a wide range in the front-rear direction, and the intake branch passages 5, 6, and 7 pass therethrough. That is, in the front part of the intake manifold, the intake branch passages 5, 6, 7 are also formed in the upper and lower intermediate members 3, 4. Although the interval between the second intake branch passage 6 and the third intake branch passage 7 is widened, the interval between the adjacent intake branch passages 5, 6, 7 is the same at the end.

  Note that the intake manifold may be composed of three members, an upper member 1, a lower member 2, and one intermediate member. In this case, the starting end of the intake branch passage is located at the front of the intake manifold. The intake branch passage is formed in a range of about the upper half circumference of the intake manifold.

At the left end (one end) of the upper member 1, an intake inlet 9 for mounting a throttle body (not shown) is open upward. The intake port 9 also communicates with the upper intermediate member 3, and the intake gas flows into the surge tank 8 from a lateral direction.

  The right end (the other end) of the upper intermediate member 3 protrudes rightward from the other members, and the EGR gas introduction unit 10 projects upward from the protruding portion. An EGR pipe is fixed to the EGR gas introduction unit 10 by flange joining (an EGR valve may be fixed to the EGR gas introduction unit 10).

(2) EGR Gas Distribution Structure Next, an EGR gas distribution structure will be described with reference to FIG. A passage for guiding the EGR gas to each of the intake branch passages 5, 6, 7 is formed in the lower intermediate member 4. That is, although the lower intermediate member 4 overlaps and is welded to the upper intermediate member 3, by forming a concave groove on the mating surface (upper surface) with the upper intermediate member 3, the exhaust gas recirculation main passage 11 and the First to third exhaust gas recirculation branch passages 12 to 14 are formed. In FIG. 3, the hatched surface overlapping with the upper intermediate member 3 is indicated by the hatched parallel lines (the same applies to FIG. 4). In order to enhance the weldability, a thin rib is often formed on the overlapped surface.

  The start end 11a of the exhaust gas recirculation main passage 11 communicates with the EGR gas introduction unit 10, and the EGR gas flows into the start end 11a from a direction perpendicular to the paper surface. For convenience, the hole of the EGR gas introduction unit 10 is indicated by reference numeral 15.

  The exhaust gas recirculation main passage 11 is disposed between the surge tank 8 and the intake branch passages 5, 6, 7, and the back surface 16 located behind the group of the intake branch passages 5, 6, 7 has a gentle curve. However, it extends smoothly in the direction in which the intake branch passages 5, 6, 7 are arranged. Therefore, the EGR gas flows smoothly toward the terminal end (toward the downstream side).

  The front face 17 of the exhaust gas recirculation main passage 11 which is close to the row of the intake branch passages 5, 6, 7 is parallel to the line of the intake branch passages 5, 6, 7; The back surface 16 is slightly curved and inclined so as to shift backward from the end toward the start end. For this reason, the exhaust gas recirculation main passage 11 has a shape that is gradually narrowed so that the groove width (cross-sectional area) decreases from the start end to the end.

The start end 11a of the exhaust gas recirculation main passage 11 protrudes to the outer end of the row of the intake branch passages 5, 6, and 7, and the start end 11a is located forward of the row of the intake branch passages 5, 6, and 7. Is approaching. Therefore, the start end portion 18 of the exhaust gas recirculation main passage 11 extending from the start end 11 a to the rear of the first intake branch passage 5 is smoothly curved in a concave shape toward the first intake branch passage 5. Therefore, the EGR gas is smoothly guided from the start end portion 18 to the end.

As described above, the groove width of the exhaust gas recirculation main passage 11 is gradually narrowed in the flow direction of the EGR gas. An approximately L-shaped first peninsula 19 is provided, and the outside of the first peninsula 19 is smoothly bent to form a start end portion 18, and the inside of the first peninsula 19 is formed as an exhaust gas recirculation main passage. A part of the EGR gas flowing through the first bag-shaped portion 11 is branched and flows backward to form a first bag-shaped portion 20. It enters the longitudinal direction of the passage 11 . Therefore, the first exhaust gas recirculation branch passage 12 extends from the entrance of the first bag-shaped portion 20 to the first intake branch passage 5. Therefore, the first exhaust gas recirculation branch passage 12 extends in the front-rear direction.

Further, a second peninsula 21 projecting toward the back surface 16 is protruded at a portion of the exhaust gas recirculation main passage 11 slightly downstream of the second intake branch passage 6, thereby forming the constricted portion 22. The first buffer portion 23 is located on the upstream side of the constricted portion 22, and the second buffer portion 24 is located on the downstream side of the constricted portion 22. Accordingly, the first buffer portion 23 has a shape in which the groove width gradually decreases toward the downstream, and the first bag-shaped portion 20 is formed at the start end of the first buffer portion 23.

  Since there is a gap between the second intake branch passage 6 and the second intake branch passage 7, the second buffer portion 24 has a pocket portion 24a that is located closer to the front than the front surface 17, and The second exhaust gas recirculation branch passage 13 and the third exhaust gas recirculation branch passage 14 are branched from the portion 24a in a state of being distributed to the left and right. Therefore, the second exhaust gas recirculation branch passage 13 and the third exhaust gas recirculation branch passage 14 extend in the left-right direction. The inner surface of the portion of the pocket portion 24a located on the side of the second peninsula 21 is an inclined surface 25 such that the width of the front and rear grooves decreases toward the third exhaust gas recirculation branch passage 14.

Also, the pocket portion 24a is located remote slightly upstream by the innermost part of the exhaust gas recirculation main passage 11. For this reason, the innermost part of the exhaust gas recirculation main passage 11 goes into the longitudinal direction of the exhaust gas recirculation main passage 11 beyond the pocket portion 24 a communicating with the first and second exhaust gas recirculation branch passages 13 and 14. It is a second bag-shaped portion 11b .

(3). Conclusion The EGR gas that has flowed into the exhaust gas recirculation main passage 11 flows from upstream to downstream. However, the groove width of the exhaust gas recirculation main passage 11 is reduced toward the downstream, Due to the presence of 22, it is divided into one flowing into the second buffer unit 24 and one remaining in the first buffer unit 23 .

Since the EGR gas has a straight traveling property, in the present embodiment, 2/3 of the EGR gas goes straight and flows into the second buffer unit 24, and the EGR gas that has flowed into the second buffer unit 24. The gas flows into the second exhaust gas recirculation branch passage 13 and the third exhaust gas recirculation branch passage 14 separately.

In this case, since the EGR gas flowing into the second buffer portion 24 changes its direction by flowing into the pocket portion 24a, the straightness of the EGR gas is reduced, and the EGR gas flows into the second exhaust gas recirculation branch passage. 13 and the third exhaust gas recirculation branch passage 14.

An inclined surface 25 is formed on the side of the third exhaust gas recirculation branch passage 14 in the pocket portion 24a, so that the EGR gas is successfully introduced into the third exhaust gas recirculation branch passage 14. The innermost portion 11b of the exhaust gas recirculation main passage 11 is formed in a dead end shape, and the EGR gas colliding with the second bag-shaped portion 11b tends to flow into the second exhaust gas recirculation branch passage 13 as a reverse flow. Thus, the inflow of the EGR gas into the second exhaust gas recirculation branch passage 13 is promoted. As a result, the EGR gas can be evenly distributed to the second exhaust gas recirculation branch passage 13 and the third exhaust gas recirculation branch passage 14.

That is, since the EGR gas has a straight traveling property, the EGR gas may flow more in the third exhaust gas recirculation branch passage 14 than in the second exhaust gas recirculation branch passage 13 unless special measures are taken . in the present embodiment, and the pocket portion 24a is present, and that the deepest portion of the exhaust gas recirculation main passage 11 is Tsu Na in the second bag-shaped portion 11b of the second buffer unit 24, inclined to the pocket portion 24a The EGR gas can be evenly distributed to the second exhaust gas recirculation branch passage 13 and the third exhaust gas recirculation branch passage 14 by a synergistic effect of the presence of the surface 25.

Although the EGR gas flows into the first buffer portion 23 with a strong straight traveling property, in the present embodiment, since the first bag portion 20 is provided in the first buffer portion 23, a part of the EGR gas is diverted while flowing back from the first buffer portion 23 flows into the first exhaust gas recirculation branch passage 12. Therefore, the momentum of the EGR gas is killed, and the EGR gas can be supplied to the first exhaust gas recirculation branch passage 12 in a stable state.

Further, since the first exhaust gas recirculation branch passage 12 is provided not at the innermost part of the first bag-shaped part 20 but at the entrance, the EGR gas flowing backward from the first buffer part 23 and flowing into the first bag-shaped part 20 is provided. As in the case of the second bag-shaped portion 11b, the momentum is reduced and the directionality toward the first exhaust gas recirculation branch passage 12 is reduced. Also from this point, it is possible to prevent the inflow ratio into the first exhaust gas recirculation branch passage 12 from increasing.

Equalizing the amount of EGR gas flowing into each of the exhaust gas recirculation branch passages 12 to 14 adjusts the degree of narrowing of the exhaust gas recirculation main passage 11 and reduces the groove width (cross-sectional area) of the constricted portion 22. Adjustment, adjustment of the area or shape of the pocket portion 24a, and adjustment of the depth of the first bag-shaped portion 20 can be easily realized.

  In addition, the exhaust gas recirculation main passage 11 and the exhaust gas recirculation branch passages 12 to 14 are provided by forming a concave groove on the lower surface of the lower intermediate member 4, or the overlapped surface of the lower intermediate member 4 and the upper intermediate member 3 is formed. It can be provided by forming a concave groove in both. When forming a concave groove in both, the depth may be the same or different from each other.

  Alternatively, the buffer section may be formed by changing the depth of the exhaust gas recirculation main passage 11 instead of or in addition to changing the groove width of the exhaust gas recirculation main passage 11 in plan view. It is possible. These are variations common to the present invention.

(3) Other Embodiments / Others FIG. 4 shows a second embodiment applied to a four-cylinder intake manifold. In this embodiment, the exhaust gas recirculation main passage 11 is provided with the third peninsula 27 between the first peninsula 19 and the second peninsula 21, so that the first buffer 23 and the second buffer A third buffer section 28 is formed between the second buffer section and the section 24. That is, two constricted portions 22 and 22 ′ are formed in the exhaust gas recirculation main passage 11, whereby the exhaust gas recirculation main passage 11 is divided into three buffer portions 23, 24 and 28.

The third peninsula 27 protrudes downstream. For this reason, a third bag-like portion 29 is formed inside the third buffer portion 28, and the entrance of the third bag-like portion 29 and the second intake branch passage 6 are connected to the second exhaust gas recirculation branch passage. And 13. A part of the EGR gas that has flowed into the third buffer unit 28 flows backward from the third buffer unit 28 and flows into the second exhaust gas recirculation branch passage 13, so that the EGR gas is reduced in power and the second exhaust gas recirculation is performed. It can flow stably into the branch passage 13.

In the present embodiment, the first to fourth intake branch passages 5, 6, 7, 30 are arranged at equal intervals. Therefore, although provided with a pocket portion 24a to the second buffer portion 24, the area of the pocket portion 24a is smaller than that in the first embodiment. The second bag-shaped part 11b is formed in the innermost part of the exhaust gas recirculation main passage 11 in the shape of a dead end, as in the first embodiment.

  Further, the second peninsula 21 is formed in a state close to the fourth intake branch passage 30. Therefore, the EGR gas flowing into the pocket portion 24a flows from the rear to the front. For this reason, even when the third exhaust gas recirculation branch passage 14 and the fourth exhaust gas recirculation branch passage 31 are simply turned left and right, the EGR gas is supplied to the third intake branch passage 7 and the fourth intake branch passage 30. And flows in evenly.

The present invention can be embodied in various ways in addition to the above embodiment. For example, it is not always necessary to provide a pocket portion, and it is also possible to form a peninsula portion and a bag-shaped portion at each exhaust gas recirculation branch passage and to branch the exhaust gas recirculation branch passage from each bag-shaped portion. It is possible. Further, it is sufficient that the EGR gas flows without largely changing the flow path on the back surface of the exhaust gas recirculation main passage, and therefore, there may be some unevenness.

  The present invention can be actually applied to an intake manifold. Therefore, it can be used industrially.

DESCRIPTION OF SYMBOLS 1 Upper member 2 Lower member 3,4 Intermediate member 5,6,7,30 Intake branch passage 8 Surge tank 9 Intake entrance 10 EGR gas introduction part 11 Exhaust gas recirculation main passage 11a Start end 11b Second bag-shaped part 12,13, 14, 31 Exhaust gas recirculation branch passage 16 Back side of exhaust gas recirculation main passage 17 Front surface of exhaust gas recirculation main passage 18 Start end side portion of exhaust gas recirculation main passage 19, 21, 27 Peninsula 20, 29 First bag-shaped portion Third bag portions 23, 24, 28 Buffer portion 24a Pocket portion

Claims (1)

A plurality of intake branch passages arranged in parallel are formed so as to penetrate the first member and the second member that are overlapped and joined,
A single exhaust gas recirculation main passage extending long in the direction in which the intake branch passages are arranged, in the vicinity of the group of intake branch passages on the mating surface of the first member and the second member; A plurality of exhaust gas recirculation branch passages branching from the passage toward each intake branch passage are formed, and exhaust gas flows from the one end to the other end of the exhaust gas recirculation main passage. So,
The exhaust gas recirculation main passage has a smooth continuous surface on the back surface opposite to the group of intake branch passages, thereby allowing the EGR gas to flow smoothly from one end to the other end. Along with
The exhaust gas recirculation main passage is provided with one or a plurality of constrictions having a reduced cross-sectional area, thereby forming a plurality of buffer portions for evenly flowing the EGR gas to each intake branch passage. A bag-shaped part into which the exhaust gas flowing from the one end toward the other end goes straight and enters each buffer part, and a bag-shaped part into which the exhaust gas flowing from the one end toward the other end flows backward. And is formed,
The exhaust gas recirculation branch passage is branched from the buffer section at a location corresponding to each of the bag sections so that the EGR gas flowing toward the innermost part of the bag section flows in.
An intake manifold for an internal combustion engine.

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