JP2000192860A - Distribution pipe of exhaust gas recirculation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance uniform distribution of EGR gas to an intake manifold, to prevent a deposit from attaching and accumulating at a jet part formed to a partition plate, and to enhance rigidity of the partition plate. SOLUTION: An inside of this distribution pipe is divided by a partition plate 13, and jets 17, 18 are respectively formed at an upstream side and a downstream side of the partition plate 13, and a passage 14 difined by the partition plate 13 is provided with EGR gas introducing inlet 1a at its one end. EGR gas flowing from the an EGR gas introducing inlet 1a to an inside of the passage 14 is made to flow in the jets 17, 18 of the partition plate 13 and made to flow into the other passage 15, and is distributed to intake manifolds 2 to 5 from the other passage 15. A first projection 19 for restraining the EGR gas from flowing to the upstream side jet 17 is provided. A second projection for promoting flowing of the EGR gas to the downstream side jet 18 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a distribution pipe for an exhaust gas recirculation device.

[0002]

2. Description of the Related Art Conventionally, in an internal combustion engine such as a diesel engine or a gasoline engine, NO
In order to reduce x, an exhaust gas recirculation (EGR) device has been adopted in which exhaust gas is recirculated into an intake manifold of an internal combustion engine.

As this device, for example, as shown in FIG.
04, a distribution pipe (surge tank) 105 is disposed in a direction orthogonal to the axial direction of the intake manifolds 101 to 104, and the inside of the distribution pipe 105 is arranged in its length direction (axial direction).
The partition 106 is disposed in the first passage 107 and the second passage 1.
08 and a first jet (communication hole) 109 and a second jet 110 are formed in the partition plate 106, and the recirculated exhaust gas (EGR gas) is supplied to the EGR gas introduction pipe 111.
Through the EGR gas inlet 112 to the first passage 107, diverted to the second passage 108 through the first and second jets 109 and 110, and formed into the first to fourth supply ports 113 to 116 formed in the second passage 108. Are distributed and supplied to the first to fourth intake manifolds 101 to 104 to enhance the distribution of the exhaust gas amount to each of the intake manifolds 101 to 104, and to make the temperature uniform.
For example, it is disclosed in Japanese Patent Application Laid-Open No. 7-189837.

By the way, as described above, the partition plate 106
A first jet 109 is formed at the center between the third supply port 115 and the fourth supply port 116, and the second jet 110 is formed at a center between the first supply port 113 and the second supply port 114.
Is formed, the amount of EGR gas flowing from the first jet 109 near the EGR gas inlet 112 to the second passage 108 tends to be larger than that of the second jet 110.

[0005] Therefore, as shown in FIG. 4, the diameter of the flow hole of the first jet 109 is made smaller than the diameter of the flow hole of the second jet 110, and
In some cases, the flow rate is adjusted to zero.

[0006]

However, the above-mentioned partition plate 106 is usually thick in order to obtain the required rigidity. Therefore, as in the case of the first jet 109, when the diameter of the hole is reduced, a separation phenomenon of an air current occurs on the wall surface of the hole, deposits are deposited on the wall surface of the hole, and the diameter of the flow hole changes. is there.

Further, if the thickness of the partition plate 106 is reduced and the jet length of the first jet 109 is shortened in order to prevent the deposition and accumulation of the deposit, the required rigidity of the partition plate 106 cannot be obtained.

[0008] Accordingly, the present invention provides a required rigidity by increasing the thickness of the partition plate, suppresses the adhesion and deposition of deposits in the jet section, and further reduces the EGR gas from the first jet and the second jet. It is an object of the present invention to provide a distribution pipe of an exhaust gas recirculation device that makes the outflow amount uniform and improves the distribution of EGR gas.

[0009]

According to a first aspect of the present invention, in order to solve the above-mentioned problems, the inside is partitioned by a partition plate, and the partition plate is located on the upstream side and the downstream side. A jet is formed and EG is inserted at one end of one of the divided passages.
An R gas inlet is provided, and the EGR gas flowing into one of the passages from the EGR gas inlet is circulated through the jets of the partition plate and diverted into the other passage. In the distribution pipe distributed to the manifold, the partition plate is formed separately from the outer wall of the distribution pipe, and the upstream portion of the upstream jet in the partition plate is configured to suppress the inflow of EGR gas into the upstream jet. One protruding portion is provided, and a second protruding portion is provided at a downstream portion of the downstream jet to promote the inflow of the EGR gas into the downstream jet.

Normally, when the upstream jet and the downstream jet have the same hole diameter, the EGR gas flowing into one passage from the EGR gas inlet is smaller than the downstream jet far from the EGR gas inlet. A large amount flows out of the upstream jet near the inlet, and the EGR gas is not evenly distributed to each intake manifold. On the other hand, as described above, the upstream jet
By providing a first protrusion for suppressing the inflow of the GR gas and providing a second protrusion for promoting the inflow of the EGR gas to the downstream jet at the downstream portion of the downstream jet, the upstream jet and the downstream Even if the diameters of the jet holes are the same, it is possible to adjust the inflow amount of the EGR gas into these jets so as to achieve a uniform distribution to each intake manifold.

Therefore, the upstream jet and the downstream jet are both formed to have a relatively large diameter and the same diameter, so that the EGR gas can be uniformly distributed to each intake manifold. By making the diameters of both jets large in this manner, the adhesion and deposition of deposits due to the separation of the airflow in each jet are suppressed, and the ability to suppress the adhesion and deposition of these deposits is to increase the thickness of the partition plate. Thus, the rigidity of the partition plate can be increased.

According to a second aspect of the present invention, in the first aspect, the first projection and the second projection are formed by raising the partition plate itself toward one of the passages. It is assumed that.

In the present invention, the main flow of the EGR gas is diverted away from the upstream jet by the raised first protrusion, and the inflow of the EGR gas into the upstream jet is suppressed. Further, the main flow of the EGR gas is redirected by the raised second protrusion to return to the downstream jet, and the inflow of the EGR gas to the downstream jet is promoted. Therefore,
The same operation as in the first invention is performed. Furthermore, since the partition plate itself is raised by drawing or the like toward one of the passages, work hardening occurs and rigidity is improved.

According to a third aspect of the present invention, in the first aspect, the first protrusion and the second protrusion are formed by cutting and raising pieces obtained by cutting and raising a partition plate toward one of the passages. It is characterized by the following.

In the present invention, by forming the first projection and the second projection by cutting and raising, the cutting and raising forms the upstream jet and the downstream jet, and the upstream jet and the downstream jet. The constituent walls of the jet become the first projection and the second projection.

Therefore, a first projection is formed immediately upstream of the upstream jet, and a second projection is formed immediately downstream of the downstream jet. Thus, the suppression of the inflow of the EGR gas and the promotion of the inflow to the downstream jet are further enhanced, and the uniform distribution of the EGR gas is further improved as compared with the second invention.

According to a fourth aspect of the present invention, in the third aspect, the cut and raised first protrusion is inclined toward the upstream jet, and the cut and raised second protrusion is connected to the downstream jet. It is characterized by being inclined to the side.

According to the present invention, the inclination of the first projection makes the flow of the EGR gas in this part smoother, further suppresses the inflow of the EGR gas into the upstream jet, and reduces the second projection. Due to the inclination of the portion, the flow of the EGR gas into the downstream jet by the portion is smoothly performed, and the flow of the EGR gas into the downstream jet is further promoted.

Therefore, the function of the second invention is further enhanced.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described based on an embodiment shown in FIGS. FIG. 1 is a sectional view of a distribution pipe provided with a partition plate showing a first embodiment.

In FIG. 1, a distribution pipe 1 is formed in a cylindrical shape having an EGR gas inlet 1a at one end.
3, is arranged so that its axial direction is orthogonal to the axial direction of the plurality of intake manifolds 2, 3, 4, 5 arranged in parallel, as in FIG. The example of FIG. 1 is an example applied to a four-cylinder engine, in which first to fourth intake manifolds 2 to 5 communicating with the first to fourth cylinders of the engine are provided. The bottom wall 1b of the distribution pipe 1 corresponding to the four intake manifolds 2 to 5
The first to fourth recirculation ports 6 to 9 are formed in each of the intake manifolds 2 to 5.
Is in communication with

On the inner surface of the peripheral wall 1c constituting the outer wall of the distribution pipe 1, a holding portion 12a formed of a concave groove 12 formed by two ridges 10, 11 is formed. The partition plate 13 is
The EGR gas inlet 1a is formed separately from the outer wall of the distribution pipe 1 and has a thickness such that the thickness thereof is slidably fitted in the concave groove 12, and is fitted into the concave groove 12 through the EGR gas inlet 1a. And inserted into the distribution pipe 1, and with the partition plate 13,
A first passage (one passage) 14 and a second passage (the other passage) 15 are formed in the distribution pipe 1 by dividing the space between the bottom surface 1d and the top surface 1e of the distribution pipe 1 into two parts. The EG of the distribution pipe 1
The R gas inlet 1a side is closed by a cover 16 which is located in the first passage 14 and has an inlet 16a formed therein.

Further, jets 17,
18 are formed. The jets 17, 18 are EGR
A desired number and a desired position are formed so as to enhance the gas distribution performance. In the example of the figure, an upstream jet 17 is formed at the center of the third and fourth recirculation ports 8 and 9,
A downstream jet 18 is formed at the center of the first and second recirculation ports 6 and 7, and a total of two downstream jets 18 are formed.

The hole diameter of the upstream jet formed in the partition plate 13 and the hole diameter of the downstream jet 18 are formed to have the same diameter.
In both cases, the diameter is set so as to suppress the adhesion and deposition of the deposit.

Near the upstream side of the upstream jet 17 in the partition plate 13, the partition plate 13 is connected to the first passage 1.
A first projection 19 raised to the fourth side by drawing or the like is formed. The first projection 19 is, as shown in FIG.
A substantially hemispherical shape is formed between the upper surface of the first projection 19 and the top surface 1e of the distribution pipe 1 except for the flow portion.

Near the downstream side of the downstream jet 18 in the partition plate 13, the partition plate 13 is connected to the first passage 1.
A second projection 20 raised to the fourth side by drawing or the like is formed. Like the first protrusion 19, the second protrusion 20 is formed in a substantially semi-spherical shape except for a flow portion between the upper surface of the second protrusion 20 and the top surface 1e of the distribution pipe 1. I have.

As described above, the EGR of the distribution pipe 1
The recirculated gas flowing from the gas inlet 1a flows into the first passage 14 as shown by the arrow, and is diverted from the first passage through the jets 17 and 18 into the second passage 15, and
It is distributed from the passage 15 into each of the intake manifolds 2 to 5 through each of the recirculation ports 6 to 9.

At this time, the EGR passing through the first projection 19
The main flow of the gas is deflected by the first protrusion 19 as shown by the arrow in FIG. 1 and passes through the upper part far from the upstream jet 17. Therefore, the EGR gas is originally generated by the upstream jet 17.
The outflow is suppressed against the tendency that a large amount of outflow occurs.

The main flow of the EGR gas that has flowed downstream after passing through the first projection 19 is, as shown by the arrow in FIG.
It hits the projection 20, turns back toward the downstream jet 18, and flows from the downstream jet 18 into the second passage 15.
Therefore, the outflow is promoted against the fact that the EGR gas originally tends to flow less from the downstream jet 18.

Therefore, the outflow amounts of the EGR gas from the upstream jet 17 and the downstream jet 18 are equalized. By equalizing in this way, the EGR gas is evenly distributed to each of the intake manifolds 2 to 5 through each of the recirculation ports 6 to 9.

FIG. 2 shows a second embodiment. In the second embodiment, the first protrusion 19 and the second protrusion 2 in the first embodiment are used.
As shown in FIG. 2, in a modification example of FIG. 2, the upstream jet forming portion of the partition plate 13 is cut and raised, and the first protrusion formed of the upstream jet 17 and a cut and raised piece on the upstream side of the upstream jet 17 is formed. 19a, the downstream jet forming portion is cut and raised, and the second protrusion 20a is formed by cutting and raising the downstream jet 18 and the cut piece on the downstream side of the downstream jet 18.

The first projection 19a is formed so as to be inclined so that its tip is directed to the downstream direction which is the direction of the upstream jet 17, and the second projection 20a is formed so that its tip is It is formed to be inclined so as to face the upstream side which is the downstream jet 18 side.

Since other structures are the same as those of the first embodiment, the same parts as those of the first embodiment are denoted by the same reference numerals and the description thereof will be omitted. In the second embodiment, the first
As in the embodiment, the flow of the EGR gas into the upstream jet 17 is suppressed by the first protrusion 19a, and the flow of the EGR gas into the downstream jet 18 is promoted by the second protrusion 20a. In the second embodiment, the distance between the upstream jet 17 and the first protrusion 19a is shorter than the distance between the upstream jet 17 and the first protrusion 19 in FIG. Since the distance from the second protrusion 20a is shorter than the distance between the downstream jet 18 and the second protrusion 20 in FIG. 1, the flow of the EGR gas into the upstream jet 17 by the first protrusion 19a is suppressed. Is larger than in the first embodiment, and the second protrusion 20a facilitates the flow of the EGR gas into the downstream jet 18 as compared with the first embodiment.

Therefore, the distribution of the EGR gas is further improved as compared with the structure of the first embodiment. Further, the first protrusion 1
9a to the downstream side, the first protrusion 19a
The flow of the EGR gas at the
By inclining the protrusion 20a to the upstream side, the inflow of the EGR gas into the downstream jet 18 is performed smoothly.
Therefore, the distribution property is further improved.

Further, since the partition plate 13 of each of the above embodiments is formed separately from the outer wall of the distribution pipe 1, and this is fitted into the outer wall through the holding portion 12a formed of the concave groove 12, so that it is fitted. Before mounting the partition plate 13, the projections 19, 19a, 20, 20a of the partition plate 13 can be easily formed. That is, as in the conventional structure shown in FIG.
06 is formed integrally with the outer wall of the distribution pipe 105 by die casting.
It is difficult to form 20, 20a.

[0036]

As described above, according to the first aspect of the present invention, uniform distribution of EGR gas to each intake manifold can be achieved by each projection.
Further, both the upstream jet and the downstream jet have the same and large hole diameter, so that the deposition and deposition of the deposit can be suppressed. Furthermore, the rigidity of the partition plate can be increased by increasing the thickness of the partition plate. Further, since the partition plate is formed separately from the outer wall of the distribution pipe, the projection can be easily formed on the partition plate.

According to the second aspect of the present invention, since the projection can be formed by raising the partition plate itself, the projection can be easily formed without using a separate projection forming component. Furthermore,
The rigidity can be improved by work hardening, and the partition plate can be made thinner.

According to the third aspect of the present invention, since the projection can be formed by bending the partition plate itself, the projection can be easily formed. Further, the distribution of the EGR gas can be further improved.

According to the fourth aspect of the present invention, the EG
The distribution of the R gas can be further improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a partially cutaway view showing an installation state of a distribution pipe and a conventional structure of the distribution pipe.

FIG. 4 is a sectional view showing a conventional distribution pipe.

[Description of Signs] 1-minute pipe 1a EGR gas inlet 2-5 intake manifold 13 partition plate 14 one passage (first passage) 15 the other passage (second passage) 17 upstream jet 18 downstream jet 19, 19a First projection 20, 20a Second projection

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinji Iwata 1-1, Kyowa-cho, Obu-shi, Aichi 1 Ai San Kogyo Co., Ltd. (72) Tetsuo Okubo 1, Toyota-cho, Toyota-shi, Aichi Prefecture Toyota Motor Co., Ltd. F term (reference) 3G062 ED05 ED10

Claims (4)

[Claims] 1. An interior is partitioned by a partition plate, and a jet is formed on the partition plate at an upstream side and a downstream side, and an EGR gas inlet is provided at one end of one of the partitioned passages.
EGR flowing from the EGR gas inlet into one of the passages
In the distribution pipe which distributes the gas through the jet of the partition plate and divides it into the other passage, and further distributes the gas from the other passage to each intake manifold, the partition plate is formed separately from the outer wall of the distribution pipe. An upstream portion of the upstream jet of the partition plate is provided with a first projection for suppressing the flow of EGR gas into the upstream jet, and a downstream portion of the downstream jet is EGR
A distribution pipe for an exhaust gas recirculation device, comprising a second projection for promoting gas inflow. 2. The distribution pipe of the exhaust gas recirculation device according to claim 1, wherein the first projection and the second projection are formed by raising a partition plate itself toward one of the passages. 3. The exhaust gas recirculation device according to claim 1, wherein the first projection and the second projection are formed by cutting and raising pieces obtained by cutting and raising a partition plate toward one of the passages. Minute piping. 4. The cut-and-raised first projection is inclined toward the upstream jet side, and the cut and raised second projection is inclined toward the downstream jet side. Distribution pipe for exhaust gas recirculation system.