JPH0335873Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The invention relates to an intake manifold for an engine, and in particular, the invention relates to an intake manifold for an engine. It concerns the intake manifold.

(Prior art) Automotive engines usually use exhaust gas recirculation (hereinafter referred to as EGR), which returns a portion of the exhaust gas discharged from the combustion chamber to the intake system in order to reduce nitrogen oxides in the exhaust gas. ) equipment is provided. The exhaust gas is extracted from the engine's exhaust system,
It is designed to be guided upstream or downstream of the throttle valve in the intake system through the EGR passage. When the EGR is introduced downstream of the throttle valve, an EGR passage is generally also provided in the intake manifold.
In that case, if it is a multi-cylinder engine, its EGR
If the passages are individually connected to the plurality of intake pipe passages of the intake manifold,
Reflux gas can be reliably distributed to each combustion chamber.

Therefore, EGR was installed on the outer surface of multiple intake pipes arranged in parallel, crossing each intake pipe.
An intake manifold with an EGR passage has been considered in which a conduit is provided and the internal passage of the EGR conduit and the internal passage of each intake pipe are communicated through ports respectively (see Japanese Utility Model Publication No. 52-21402). ).

Incidentally, such an intake manifold is generally formed as a cast product of aluminum alloy. However, it is difficult to form a small-diameter port that communicates the EGR passage with the intake pipe internal passage as described above by casting. Therefore, in such a case, after casting the intake manifold, as shown in FIG. A port 5 is formed to communicate the passage 2 with an internal passage 4 of the intake pipe 3. Then, a working hole 6 formed on the top surface of the EGR conduit 1
is sealed by a plug 7.

In that case, conventionally, after inserting the plug 7 into the working hole 6, a cover 8 made of aluminum alloy is covered and the cover 8 is melted to fix the plug 7 and seal the working hole 6. I was trying to do that.

(Problem to be solved by the invention) However, in a device using such a sealing means, in addition to the step of inserting the plug 7, the lid 8 is
Not only is a step of covering and melting required, but the melted lid 8 is distorted and solidified, resulting in a problem in that the appearance is impaired.

It would be good if it could be sealed by press-fitting the plug 7 into the working hole 6, but since aluminum alloy is soft, the same could be done in the working hole 6 of the aluminum alloy EGR conduit 1. When trying to press fit the plug 7 made of the material, galling occurs between the plugs and the plug 7 tends to come off even if it is press fit. In addition, conduit 1 has an internal EGR
The temperature becomes high due to the high temperature exhaust gas introduced into the passage 2, so if the conduit 1 and the plug 7 are made of different materials, the plug 7 will be heated due to the difference in thermal expansion.
There is a risk that the pipe may come off or cracks may occur in the conduit 1.

The present invention was developed in view of these problems, and its purpose is to enable a plug made of the same material as the EGR pipe to be press-fitted into a working hole formed in the EGR pipe without causing galling. The purpose is to ensure that the working hole remains sealed.

(Means for solving the problem) In order to achieve this objective, the present invention involves press-fitting an alumite-treated aluminum alloy cone plug into a working hole formed in an aluminum alloy EGR conduit. I have to.

(Function) As described above, by anodizing the cone plug, the surface of the plug becomes harder than that of the EGR conduit made of aluminum alloy. Therefore, even when the plug is press-fitted into the working hole of the EGR conduit, galling does not occur between the plugs and the plug is reliably held. And that corn plug
By using the same material as the EGR pipe,
Since their thermal expansion coefficients are the same, even if high-temperature exhaust gas is introduced into the EGR pipe, the plug may come off or a gap may be created between the plug and the working hole, causing exhaust gas to leak. There will be no more things like that.

(Example) Hereinafter, an example of the present invention will be described using the drawings.

1 to 3 show an embodiment of the intake manifold according to the present invention, and FIG. 1 is a vertical sectional view of the EGR conduit portion of the intake manifold,
FIG. 2 is a plan view of the intake manifold. Moreover, FIG. 3 is a schematic side view of the engine equipped with the intake manifold.

As is clear from FIG. 3, the engine body 10
The cylinder head 11 is provided with an intake port 13 and an exhaust port 14 that communicate with the combustion chamber 12 and open on both sides of the cylinder head 11, respectively. An intake manifold 15 is attached to the side surface of the cylinder head 11 where the intake port 13 opens, and an exhaust manifold 16 is attached to the side surface where the exhaust port 14 opens.

The intake manifold 15 includes a distribution chamber 17 disposed on the side of the engine body 10 and an intake pipe 1 that connects the distribution chamber 17 to the intake port 13.
8. The engine main body 10 is an in-line four-cylinder engine, and as is clear from FIG. 2, the distribution chamber 17 is cylindrical and extends substantially horizontally, substantially parallel to the longitudinal direction of the engine main body 10. One end surface of the distribution chamber 17 is open as an intake inlet 19, and a throttle body mounting flange 20 for mounting a throttle body is provided on the end surface. Four intake pipes 18, 18, . . . corresponding to the number of cylinders are opened on the lower surface of the distribution chamber 17. Each intake pipe 18 has a vertical portion 18a extending downwardly from its distribution chamber 17, and a horizontal portion 18b extending gently curved and generally horizontally from the lower end of the vertical portion 18a. In addition, a common mounting flange 2 is provided at the end of the intake pipes 18, 18, . . . on the cylinder head 11 side.
1 is provided, and this mounting flange 21 allows the intake manifold 15 to be attached to the cylinder head 11.
and each intake pipe 1 of the
8, 18, . . . are connected to four intake ports 13, 13, . . . of the cylinder head 11, respectively.

These intake pipes 18, 18, . . . are arranged in parallel with each other, and as shown in FIG. 3, the entire intake manifold 15 forms a substantially L-shape when viewed from the side. ing. and,
An air cleaner 22 is attached to the back side of the intake manifold 15. The mounting flange 21 also has a cylinder head 11.
A fuel injection nozzle 23 capable of injecting fuel is attached to each intake port 13 of the engine.

As is clear from FIG. 2, an EGR valve mounting flange 24 for mounting an EGR valve (not shown) is provided on the side of the intake pipe 18 located at the most lateral side. The EGR valve has one end connected to the exhaust manifold 16.
A portion of the engine's exhaust gas is directed through the EGR tube. An EGR conduit 25 is provided on the side surface of the side intake pipe 18, one end of which opens into the EGR valve mounting flange 24 and guides the recirculation gas supplied from the EGR valve. This EGR conduit 25 extends from the side surface of the intake pipe 18 to the top side, and further extends from the horizontal portions 18b, 18b, of the four intake pipes 18, 18, .
...extends across the top surface. This EGR
The EGR passage 26 formed inside the conduit 25 is
It extends from the opening 24a of the EGR valve mounting flange 24 to the center of the four intake pipes 18, 18, .
18,... is made to reach the upper surface.

As shown in FIG. 1, all intake pipes 18,
Working holes 27, 27, . . . are provided in the upper wall of the EGR conduit 25 that extends across the intake pipes 18, . Each working hole 27, 27, . Exhaust gas introduction ports 29, 29, . . . are formed at positions corresponding to . The ports 29, 29 on both sides have a larger diameter than the ports 29, 29 in the center, and the EGR
The reflux gas flowing from the center of the passage 26 is evenly distributed to each of the intake pipe passages 28, 28, . . . . A sealing material having heat resistance and corrosion resistance is applied to the inner surface of each of the working holes 27, 27, . . . , and the intake manifold 1
Corn plugs 30, 30, . The cone plug 30 is alumite-treated and has an oxide film formed on its surface.

The opening 31 provided in the center of this EGR conduit 25 for removing sand from the core during casting also has a similar plug 32.
It is designed to be sealed by.

In an engine equipped with such an intake manifold 15, during operation, the air cleaner 22
The clean air sucked through is led to the throttle body via an air duct and introduced into the distribution chamber 17 through the intake inlet 19 of the intake manifold 15. In the distribution chamber 17, the internal passages 28 of each intake pipe 18, 18, .
28, . . . and guided to the corresponding combustion chambers 12 through each intake port 13 of the cylinder head 11. On the other hand, part of the exhaust gas combusted and exhausted in the combustion chamber 12 is extracted from the exhaust manifold 16, and is supplied to the EGR passage 26 under control of the EGR valve. The exhaust gas in the EGR passage 26 is distributed to the internal passage 28 of each intake pipe 1 through the exhaust introduction port 29, mixed with air, and returned to each combustion chamber 12 as intake air. Furthermore, during this period, fuel is injected from the fuel injection nozzle 23 toward each intake port 13 of the cylinder head 11, and the fuel is supplied to the combustion chamber 12 together with the intake air.

Such an intake manifold 15 is integrally formed with the distribution chamber 17, the intake pipes 18, 18, . . . , the EGR conduit 25, etc., and is cast from an aluminum alloy. In that case, each intake pipe 18, 18,...
internal passages 28, 28, ... and EGR passage 26
is formed during its casting by using a sand core. After the intake manifold 15 is cast, a working hole 27 and an exhaust gas introduction port 29 are formed by drilling holes from the upper surface of the EGR conduit 25. After drilling port 29, work hole 2
A heat-resistant and corrosion-resistant sealing material is applied to the inner surface of the cone plug 7, and the cone plug 30 is press-fitted into the working hole 27. The cone plug 30 is formed in advance from an aluminum alloy, which is the same material as the intake manifold 15, and its surface is anodized.

By manufacturing the intake manifold 15 in this manner, it is possible to reliably form the exhaust introduction port 29 with an appropriate diameter, and the cone plug 30 can be simply press-fitted into the working hole 27. This makes it easier to seal the working hole 27. As the cone plug 30, we use an alumite-treated one, so that there will be no galling between the EGR conduit 25 and the plug 30 when it is press-fitted, and the press-fitted plug 30 will come off. There will be no fear. Also, the corn plug 30 is EDR
Since it is made of the same aluminum alloy as the conduit 25, the plug 30 and the EGR conduit 25 can be easily connected even when high-temperature exhaust gas is introduced.
There is no difference in thermal expansion between the working hole 2 and
The hermeticity of No. 7 is reliably maintained. Furthermore, if a sealant is applied between the working hole 27 and the plug 30 as described above, leakage of exhaust gas within the EGR passage 26 can be more reliably prevented.
By making the sealing material heat-resistant and corrosion-resistant, its sealing properties will not be impaired even by high-temperature and corrosive exhaust gas.

In addition, in the above embodiment, the working hole 27 is
After casting the intake manifold 15, the working hole 27 is formed by a drill.
It may also be formed at the same time during casting to hold down the core or the like.

Furthermore, in the above description, it is assumed that the EGR conduit 25 is provided on the upper surface of the horizontal portion 18b of the intake pipe 18 when the intake manifold 15 is attached to the engine body 10.
The EGR conduit 25 may be provided on the side surface of the vertical portion 18a or the lower surface of the horizontal portion 18b of the intake pipe 18 in that state. The present invention is similarly applicable to such cases as well.

(Effect of the invention) As is clear from the above explanation, according to the invention, the internal passage of the intake pipe and the internal passage of the EGR pipe integrally cast in the intake pipe can be connected from the outside of the EGR pipe. In an intake manifold that is connected to each other by an exhaust introduction port formed by perforation, the intake manifold is provided for the perforation.
The working hole in the outer wall of the EGR conduit is sealed by press-fitting a cone plug formed from the same aluminum alloy as the EGR conduit and treated with alumite, making it easy to seal the working hole. In addition, the appearance of the work hole remains can be improved. Additionally, there is no longer a difference in thermal expansion between the cone plug and the EGR conduit, and since the plug is alumite-treated to have a high surface hardness, galling does not occur when the plug is press-fitted. Therefore, there is no fear that the press-fitted plug will come off, and the sealing performance of the working hole will be reliably maintained.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the intake manifold according to the present invention, and shows a vertical sectional view of the exhaust gas recirculation conduit portion that crosses the intake pipe of the intake manifold;
Fig. 2 is a partially cutaway plan view of the intake manifold, Fig. 3 is a partially cutaway schematic side view of an engine equipped with the intake manifold, and Fig. 4 shows an example of a conventional intake manifold. 2 is a partial sectional view taken in a vertical section similar to FIG. 1. FIG. DESCRIPTION OF SYMBOLS 10...Engine body, 15...Intake manifold, 16...Exhaust manifold, 17...Distribution chamber, 18...Intake pipe, 24...Exhaust recirculation valve mounting flange, 25...Exhaust recirculation conduit, 26...
...Exhaust recirculation passage which is an internal passage of the exhaust recirculation conduit,
27... Working hole, 28... Internal passage of intake pipe, 2
9...Exhaust introduction port, 30...Cone plug.

Claims (1)

[Scope of Claim for Utility Model Registration] Comprising an intake pipe and an aluminum alloy exhaust recirculation conduit integrally cast with the intake pipe, and a pipe wall between the internal passage of the intake pipe and the internal passage of the exhaust recirculation conduit. An exhaust gas introduction port that communicates between these internal passages is formed in the exhaust gas recirculation conduit, and a working hole for drilling the exhaust gas introduction port is provided in the outer wall of the exhaust gas recirculation conduit, and the working hole includes: An intake manifold with an exhaust gas recirculation passageway, characterized by a press-fitted anodized aluminum alloy cone plug.