JPS5922287Y2 - EGR passage device for multi-cylinder internal combustion engine - Google Patents

Description

[Detailed Description of the Invention] The present invention is an EGR system suitable for application to internal combustion engines, particularly four-stroke multi-cylinder internal combustion engines having cross-flow type combustion chambers.
(Exhaust gas recirculation) Concerning passage device.

In 4-stroke internal combustion engines, for exhaust gas purification measures,
EGR is often performed.

To perform this EGR, the exhaust system and intake system must be connected
Although it is necessary to provide a GR passage, conventionally, all or part of this EGR passage has been used as an EGR pipe exposed to the outside of the engine, bypassing the cylinder head portion and a portion of the cylinder head cover.

However, if a separate EGR pipe is provided to bypass the cylinder head and the like as in the above-mentioned conventional system, the overall structure will of course become complicated, and the EGR pipe will become an obstruction, making it unfavorable for maintenance.

In particular, when attempting to perform maintenance on the cylinder head immediately after side-opening operation, the EGR pipe is quite hot, so maintenance cannot be started until the EGR pipe has cooled down sufficiently.

This invention solves the above problems, and the EGR passage is
The present invention is characterized in that it is constructed by simply connecting the intake and exhaust manifolds to the cylinder head, thereby eliminating the need to separately provide an EGR pipe for bypassing the cylinder head and the like.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a cylinder head, which is designed for an in-line four-cylinder engine having four cross-flow combustion chambers 2.

This cylinder head 1 has one end surface (lower end surface in FIG. 1) extending along the arrangement direction of the combustion chambers 2 as an intake manifold connection surface 1a, to which a connection flange surface 3a of the intake manifold 3 is connected. While fixed, the other end surface (first
The upper end surface in the figure) is an exhaust manifold connection surface 1b, to which a connection 7 flange surface 4a of the exhaust manifold 4 is connected and fixed.

In this embodiment, since the engine is a two-valve intake engine, the cylinder head 1 is formed with a high-load intake port 5 and a low-load intake port 6 for each combustion chamber 2, and accordingly Also, the intake manifold 3 is connected to the high load branch path 3b.
and four low-load branch paths 3C are formed.

The intake manifold 3 has an exhaust gas intake passage 7 formed in its pipe wall, while the exhaust manifold 4 has an exhaust gas extraction branch passage 8 formed therein, and both passages 7 and 8 are connected to the cylinder head 1. These three passages 7, 8.9 constitute an EGR passage for introducing exhaust gas in the exhaust manifold 4 into the intake manifold 3.

The communication passage 9 is located at one end in the arrangement direction of the combustion chambers 2, and is configured as a straight line in the cylinder head 1, with one end 9a opening to the intake manifold connection surface 1a, and the other end 9b opening to the exhaust manifold connection surface 1a. It is opened in the manifold connection surface 1b.

From the relationship with the opening positions of both ends 9 a and 9 b of this communication passage 9, the intake passage 7 of the intake/exhaust manifolds 3 and 4
and the extraction passage 8 are the opening end 7 on the connection surface side of the cylinder head 1.
a.

8a is opened toward one end of the combustion chamber 2 in the arrangement direction.

Of course, gaskets (not shown) are inserted between the elements 1 and 3, and between the elements 1 and 4.
A communication port for this purpose is opened.

Due to manufacturing considerations, the exhaust gas intake passage 7 formed in the intake manifold 3 includes, in order from the upstream side (the side close to the exhaust system passage), a passage 7b extending in the same straight line as the communication passage 9;
In addition to the passage 7C that obliquely intersects with b and extends to the vicinity of the branching part of the intake manifold 3, there are three passages 7 formed near the branching part.
d, 7e (valve chamber of EGR valve described later), 7f
An EGR valve 10 for adjusting the amount of EGR is provided near the branch.

The passage 7C is opened from the left end side of the intake manifold 3 in FIG.

In addition, 12 in FIG. 1 is opened in the cylinder head 1,
This is a through hole for a tightening bolt for fixing it to a cylinder (path shown), and the communication path 9 is connected to the bolt through hole 12.
It is formed closer to the outer peripheral edge of the cylinder head 1 than the outer peripheral edge of the cylinder head 1 .

Further, numeral 13 in the figure is an exhaust port.

Although the embodiments have been described above, the present invention is not limited to the following.
The upper part of the cylinder head is complicated, such as those with dual intake passages, those with a sub-intake passage for gas injection (for generating swirl), and those with two exhaust valves. The present invention can be similarly applied to an engine, but it can also be applied to an ordinary engine having a single intake valve and a single intake passage and a single exhaust valve and a single exhaust passage.

Also, in order to form an EGR passage in the intake and exhaust manifold,
This can be done by casting, drilling, pipe casting, etc.

As is clear from the above, in this invention, the EGR passage is constructed simply by connecting the intake and exhaust manifolds to the cylinder head, which eliminates the trouble of connecting them using a separate EGR pipe, and allows assembly of the engine. It is advantageous for upper evacuation.

Furthermore, since the EGR pipe is not located above the cylinder head, the surrounding structure is extremely simple, which is extremely advantageous in terms of maintenance.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing one embodiment of the present invention, and Fig. 2 is a plan view showing an embodiment of the present invention.
It is a sectional view taken along the line II-II. 1... Cylinder head, 1a... Intake manifold connection end surface, 1b... Exhaust manifold connection end surface, 2... Combustion chamber, 3...・Intake manifold, 4...Exhaust manifold, 7...
...Exhaust gas intake path, 8...Exhaust gas extraction path, 9
...Communication path, 12...Through hole (for tightening bolt).

Claims (2)

[Scope of utility model registration request] (1) A multi-cylinder internal combustion engine in which an intake manifold is connected to one end face of the cylinder head along the direction in which the combustion chambers are arranged, and an exhaust manifold is connected to the other end face, wherein the combustion chambers are arranged in the cylinder head. On one end side in the direction, a communicating passage is formed, one end of which opens to a connecting end surface of the intake manifold, and the other end opens to a connecting end surface of the exhaust manifold; forming an exhaust gas intake passage connected to one end of the communication passage; forming an exhaust gas extraction passage in the exhaust manifold that opens at a cylinder head connecting end face and connected to the other end of the communication passage; and connecting the communication passage and the exhaust gas intake passage; From the inlet and exhaust gas outlet,
An EGR passage device for a multi-cylinder internal combustion engine, comprising an EGR passage. (2) Utility model registration Claim 1, wherein the communicating passage is located closer to the outer peripheral edge than a through hole for a tightening bolt for fixing the cylinder head to the cylinder.