JP4045630B2 - Engine intake system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an intake system for an engine to which an intake manifold having an intake passage communicating with a cylinder of the engine is attached, and in particular, an exhaust gas recirculation device (Exhaust Gas Recirculation) that recirculates a part of engine exhaust to the intake manifold. (Hereinafter referred to as EGR) belongs to the technical field.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as an intake device for this type of engine, for example, as disclosed in Japanese Patent Publication No. 9-2582966, an intake manifold made of resin is used to reduce weight and improve productivity. ing. In this system, the resin intake manifold is thermally treated by the high-temperature exhaust gas recirculation gas (EGR gas) by elaborating the mounting structure of the exhaust gas recirculation pipe that leads part of the engine exhaust to the intake manifold and the intake manifold. The effect is reduced. That is, an outer tube is disposed in a concentric position so as to surround the open end of the exhaust gas recirculation pipe, thereby forming a double structure, and the outer tube is provided so as to protrude into the intake manifold, and the exhaust gas recirculation pipe and the outer tube are provided. Are connected at the projecting end portion into the intake manifold so that the insulating air layer is partitioned between them, so that heat is released to the outside air through the insulating air layer and the outer tube to the intake air flowing into the intake manifold. It is designed to keep the amount of heat transferred to the intake manifold small by encouraging heat dissipation from the air.
[0003]
[Problems to be solved by the invention]
By the way, in general, a throttle body equipped with a throttle valve for restricting intake air is disposed at the intake upstream end of the intake manifold. However, when a resin intake manifold is employed as in the conventional intake device described above, Due to the lack of rigidity, a separate bracket is provided to support the throttle body and the like. However, this is contrary to the recent demand for weight reduction and there is a problem that productivity is lowered due to an increase in the number of parts.
[0004]
Moreover, in the above-described conventional intake device, the resin intake manifold has been devised to reduce the thermal influence received from the high-temperature EGR gas, but the structure is not simple and can be further improved. There remains room for.
[0005]
The present invention has been made in view of such various points, and the object of the present invention is to improve the rigidity so as to support the throttle body and the like by devising the structure of the resin intake manifold. An object of the present invention is to make it possible to reduce the thermal influence from a high-temperature EGR gas or the like with a simpler configuration than that of the prior art.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, in the solution means of the present invention, a passage for an additional gas such as EGR gas added to the intake manifold is formed in the engine body, and an end thereof is opened on the side surface on the intake manifold side. A support portion for supporting the portion of the intake manifold where the common passage is formed with respect to the engine body is provided, and an introduction passage for communicating the opening of the additional gas passage with the common passage is formed in the support portion.
[0007]
That is, according to the first aspect of the present invention, a plurality of branch passages individually communicating with the plurality of cylinders of the engine, a collecting portion in which upstream portions of the respective branch passages are gathered, and the plurality of cylinders from the gathering portion mounted intake manifold and a common passage extending toward the one side in the column direction of the cylinder is Ri Na, the intake upstream end of the common passage, the throttle body is disposed with a built-in throttle valve for throttling the intake Assumes an engine intake system.
[0008]
In the engine, a first passage for supplying EGR gas from the EGR valve to the intake manifold is opened at the side surface to which the intake manifold is attached , and exhausted through the EGR valve. A second passage for connecting to the system is formed, and the intake manifold includes a branch portion in which the plurality of branch passages are formed and a support for supporting a portion corresponding to the common passage to the engine. with parts and is formed integrally, it is integrally formed on the branch portions and the support portion, though the bonding surface to be attached to the engine is provided, to those the support portion, the opening of the first passage the common passage introducing passage communicating with is formed above the said bonding surface, with each opening in the downstream side of the branch passage is arranged in the cylinder row direction, side by side in their respective openings A configuration is also the opening of the entrance passage is located.
[0009]
According to this configuration, since the portion corresponding to the common passage of the intake manifold is supported by the support portion with respect to the engine, the support rigidity of this portion can be increased. And the support part is integrally formed with an intake manifold with a branch part, and the joint surface formed integrally in them is joined to an engine. In other words, the portion corresponding to the common passage of the intake manifold is connected and supported to the engine integrally with the branch portion via the support portion, so that the rigidity of the intake manifold becomes extremely high and is disposed at the intake upstream end of the common passage. The throttle body can be supported without providing a separate bracket or the like.
[0010]
The first passage formed in the engine opens to a position corresponding to the common passage on the side surface on the intake manifold side, and an introduction passage communicating the opening and the common passage is formed in the support portion. Therefore, EGR gas can be introduced into the intake manifold with a compact configuration.
[0011]
In the invention described in claim 2, the intake manifold in the invention described in claim 1 is made of resin. As a result, the resin intake manifold often lacks rigidity compared to the metal intake manifold, so that the effect of increasing the rigidity of the intake manifold according to the first aspect of the invention is extremely effective.
[0012]
In the invention of claim 3, wherein the introduction passage that put to a second aspect of the invention, in a larger diameter than the opening of the first passage, and which is provided to surround the entire opening And
[0013]
In this, the introduction passage, from the opening of the first passage is formed to have a larger diameter, and so are provided so as to surround the entire opening, introduced through the opening in fluid communication the first passageway Direct blowing of high-temperature exhaust gas (EGR gas) flowing in the passage is suppressed. Therefore, the thermal influence on the intake manifold can be reduced with a very simple configuration.
[0014]
According to a fourth aspect of the present invention, a heat-resistant pipe member is provided around the opening of the first passage in the third aspect of the invention and projects with a gap from the inner peripheral surface of the introduction passage. It shall be.
[0015]
Thus, the high-temperature exhaust gas (EGR gas) that has circulated through the first passage is cooled by the intake air flowing through the intake manifold while flowing through the inside of the heat-resistant pipe member from the opening, and then from the introduction passage. It circulates in the intake manifold. Further, the heat-resistant pipe member has a gap between the inner peripheral surface of the introduction passage and does not directly transfer heat. Therefore, the thermal influence of the exhaust on the intake manifold can be further reduced .
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0017]
1 and 2 show an embodiment in which an engine intake device A according to the present invention is applied to an in-line four-cylinder gasoline engine. In the figure, 1 is an engine body composed of a cylinder head 2 and a cylinder block 3, An intake manifold 4 is attached to the cylinder head 2. The intake manifold 4 is formed by integrally bonding three members formed by injection molding using a polyamide resin as a main material, and has four branches individually communicated with four cylinders (not shown) of the engine. The branch portion 4a in which the passages 5, 5, 5, and 5 are formed, the upstream portion of each branch passage 5 is gathered, the gathering portion 4b in which the surge tank 6 is formed, and the intake upstream side of the surge tank 6 A common passage 7 is formed, and includes a cylindrical common passage portion 4c extending obliquely upward on one side (right side in FIG. 1) in the cylinder row direction.
[0018]
A rectangular flange surface 4d is formed on the intake upstream end surface of the common passage portion 4c, and the common passage is adjusted on the flange surface 4d while adjusting the flow rate of intake air taken in through an air filter (not shown). 7 is disposed. The intake air flowing from the throttle body 8 to the common passage 7 is distributed from the surge tank 6 to each branch passage 5 and supplied to each cylinder of the engine.
[0019]
A side surface of the cylinder head 2 on the side of the intake manifold 4 is formed with a joint surface 2a joined to the intake manifold 4, and the joint surface 2a has an intake port 9 individually communicated with four cylinders of the engine. , 9, 9, and 9 are opened in a substantially straight line in the left-right direction of FIG. The cylinder head 2 is formed with an EGR passage 10 (shown only in FIG. 2) for returning a part of the exhaust from the engine to the intake manifold 4 side. The EGR passage is formed on the joint surface 2a. Ten openings 10a are formed side by side on the one side (right side in FIG. 1) in the cylinder row direction and slightly below the respective openings of the four intake ports 9, 9, 9, 9.
[0020]
On the other hand, the intake manifold 4 is provided with a support portion 4e for supporting the common passage portion 4c with respect to the engine body 1 so as to protrude toward the engine body 1, and an opening portion 10a of the EGR passage 10 is provided inside the support portion 4e. An introduction passage 13 communicating with the common passage 7 is formed. The inlet passage 13 is connected to the cylinder head 2 integrally with the openings of the branch passages 5, 5, 5, 5, so that they are connected to the branch portion 4 a and the support portion 4 e of the intake manifold 4. Are disposed on a joint surface 4f formed integrally with the.
[0021]
That is, as shown in FIG. 3, on the joint surface 4f, the branch passages 5, 5, 5, and 5 are aligned in the cylinder row direction (left and right in the figure) so as to correspond to the intake ports 9 of the cylinder head 2. Further, the introduction passage 13 formed in the support portion 4e is arranged on one side (the left side in the figure) in the cylinder row direction and slightly below the opening portions of the branch passages 5, 5, 5, and 5. It is open.
[0022]
The intake manifold 4 includes five fastening bolts 15, 15, 15, 15, 15 (see FIG. 1) arranged diagonally so as to sandwich the intake ports 9, and one side in the cylinder row direction ( 1 is fastened to the cylinder head 2 by two fastening bolts 16 and 16 disposed so as to surround the opening 10a of the EGR passage 10 together with the fastening bolt 15 at the end, and the collecting portion 4b and the common passage portion. In 4c, it is fastened to the cylinder block 3 by fastening bolts 17 and 17, respectively, and is securely attached to the engine body 1.
[0023]
As described above, the common passage portion 4c of the intake manifold 4 is supported by the connection support portion 4e with respect to the cylinder head 2 to increase the support rigidity, and the connection support portion 4e is integrated with the branching portion 4a. In particular, since the joint surface 4f is fastened to the cylinder head 2, the processing accuracy of the intake manifold 4 and the mounting accuracy to the cylinder head 2 are also increased.
[0024]
A blow-by port 19 is connected to the engine block 3 by a hose (not shown) and distributes blow-by gas from the engine to the common passage 7.
[0025]
Next, the configuration of the EGR passage 10 and the introduction passage 13 will be described with reference to FIG.
[0026]
The EGR passage 10 is opened to the joint surface 2a in the cylinder head 2, while being drilled in an L shape and opened to the end surface 2b on one side in the cylinder row direction (front side in FIG. 4), The end surface 2b opens below the opening portion 10c of the first passage 10b with a predetermined interval, and is drilled in an L shape and is opposite to the intake manifold 4 (on the right side in FIG. 4) side surface 2c (FIG. 2). And a second passage 10d connected to the engine exhaust system by a hose (not shown). An EGR valve (not shown) is disposed on the end surface 2b of the cylinder head 2 so as to communicate with the opening 10c of the first passage 10b and the opening 10e of the second passage 10d. Thus, the flow rate of EGR gas from the exhaust side to the intake side, that is, from the second passage 10d to the first passage 10b is adjusted. Thus, by forming the EGR passage 10 in the cylinder head 2, the temperature of the EGR gas can be lowered to some extent.
[0027]
The introduction passage 13 is formed in the support portion 4e that supports the common passage portion 4c of the intake manifold 4 with respect to the cylinder head 2 as described above, and has a larger diameter than the opening portion 10a of the EGR passage 10. 4 is provided so as to surround the entire opening 10a in a state of being fastened to the cylinder head 2. Further, the opening portion 10a of the EGR passage 10 protrudes in a direction substantially orthogonal to the joint surface 2a of the cylinder head 2 and has a predetermined amount of clearance between the inner wall of the introduction passage 13 and heat resistance. A pipe member 20 is disposed.
[0028]
With this configuration, the high-temperature EGR gas that has circulated through the EGR passage 10 circulates in the heat-resistant pipe member 20 from the opening 10a, and is sufficiently cooled by the intake air flowing in the common passage 7 during this period. It circulates in the common passage 7.
[0029]
Therefore, in this embodiment, since the common passage portion 4c of the intake manifold 4 is fastened and supported to the cylinder head 2 integrally with the branch portion 4a via the connection support portion 4e, the intake manifold 4 made of resin is used. However, the rigidity is extremely high, and the throttle body 8 disposed at the end of the common passage portion 4c can be supported without providing a separate bracket or the like.
[0030]
Further, the EGR passage 10 formed in the cylinder head 2 opens at a position corresponding to the common passage 7 on the side surface on the intake manifold 4 side, and the introduction passage 13 communicates with the opening 10 a and the common passage 7. Is formed inside the support portion 4e, the configuration for introducing the EGR gas into the intake manifold 4 can be made extremely compact.
[0031]
Further, the EGR gas flowing through the common passage 7 through the introduction passage 13 is sufficiently cooled while flowing through the heat resistant pipe member 20, and between the heat resistant pipe member 20 and the inner wall of the introduction passage 13. Therefore, the heat influence from the high temperature EGR gas on the entire intake manifold 4 including the introduction passage 13 can be reduced with a very simple configuration.
[0032]
In addition, this invention is not limited to the said embodiment, Other various embodiment is included. That is, in the above embodiment, the intake device A is applied to an in-line four-cylinder engine. However, the present invention is not limited to this, and the present invention is also applicable to, for example, a single cylinder engine to a 12 cylinder engine. In the above embodiment, the resin intake manifold 4 is used. However, the present invention is not limited to this. For example, a light alloy intake manifold may be used .
[0033]
In the above embodiment, the EGR gas is circulated in the intake manifold 4 after being cooled in the heat resistant pipe member 20, but the heat to the intake manifold 4 is not provided even if the heat resistant pipe member 20 is not provided. The impact is reduced to some extent .
[0034]
【The invention's effect】
As described above, according to the engine intake device of the first aspect of the present invention, the portion corresponding to the common passage of the intake manifold can be supported on the engine body by the support portion to increase the support rigidity of this portion. In addition, since the support portion is integrally formed with the intake manifold together with the branch portion and they are integrally connected and supported by the engine, the rigidity of the intake manifold becomes extremely high, and at the intake upstream end of the common passage. The disposed throttle body can be supported without providing a separate bracket or the like.
[0035]
Further, since the opening portion of the first passage formed in the engine body is communicated with the common passage by the introduction passage formed in the support portion, it is possible to introduce the EGR gas to the intake manifold with a compact configuration. it can.
[0036]
According to the second aspect of the present invention, by adopting the resin intake manifold, the effect of increasing the rigidity of the intake manifold becomes extremely effective.
[0037]
According to the third aspect of the present invention, it is possible to prevent high-temperature exhaust gas flowing from the opening of the first passage into the introduction passage from being directly blown to the inner wall of the introduction passage, and to heat the resin intake manifold. Can be reduced with a very simple configuration.
[0038]
According to the invention described in claim 4, since the high-temperature exhaust gas flowing from the opening portion of the first passage into the introduction passage can be cooled in the heat-resistant pipe member, the thermal influence of the high-temperature exhaust gas on the intake manifold. Can be further reduced .
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of the present invention.
FIG. 2 is a side view of FIG.
3 is a YY cross-sectional view of FIG. 2 showing the configuration of the joint surface of the intake manifold.
4 is a cross-sectional view taken along line XX in FIG. 1 showing the configuration of an EGR passage and an introduction passage.
[Explanation of symbols]
A Engine intake system 1 Engine body 4 Intake manifold 4c Intake manifold common passage 4e Intake manifold support 4f Intake manifold interface 5, 5, 5, 5 Branch passage 6 Surge tank (collecting part)
7 Common passage 8 Throttle body 10 EGR passage (exhaust gas recirculation passage)
10a EGR passage opening 13 introduction passage 20 heat resistant pipe member

Claims (4)

A plurality of branch passages individually communicating with a plurality of cylinders of the engine, a collection portion in which upstream portions of the respective branch passages are gathered, and from the gathering portion toward one side in the cylinder row direction of the plurality of cylinders Ri Na mounted intake manifold and a common passage extending in the intake upstream end of the common passage, the intake system of the engine throttle body that is disposed with a built-in throttle valve for throttling the intake air,
Inside the engine, a side surface to which the intake manifold is attached opens to one side in the cylinder row direction, and a first passage for supplying EGR gas from the EGR valve to the intake manifold, and the EGR valve as an exhaust system A second passage for connection is formed,
The above intake manifold, and a branching portion in which the plurality of branch passages are formed, together with a support portion for supporting to the engine a portion corresponding to the common passage are integrally formed, at its branch portion and the support portion It is integrally formed and has a joint surface that is attached to the engine.
The support portion is formed with an introduction passage that communicates the opening of the first passage with the common passage ,
On the joint surface, the openings on the downstream side of the branch passage are arranged side by side in the cylinder row direction, and the openings of the introduction passage are also arranged along with the openings. An intake system for an engine characterized by that. In claim 1,
An intake system for an engine, wherein the intake manifold is made of resin. In claim 2,
Introduction passage, an intake device for an engine, characterized in that is provided so as to surround the whole and opening a larger diameter than the opening of the first passage. In claim 3,
An engine air intake device characterized in that a heat-resistant pipe member is provided around the opening of the first passage so as to protrude from the inner peripheral surface of the introduction passage with a gap .

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