JPH0523823Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention attempts to uniformly recirculate exhaust gas to each cylinder of a four-cylinder, four-stroke engine.

(Prior Art) Methods for distributing exhaust gas to each cylinder include a collecting section introduction method and an individual cylinder distribution method. In the collecting section introduction method, a common return passage is connected to the collecting section upstream of the manifold, and in the cylinder distribution method, each intake manifold has a communication port, and each communication port is connected to one exhaust inflow chamber. It was opened to (Jitsukai 57-
No. 136853).

(Problems to be solved by the invention) Among the above-mentioned conventional technologies, the collecting part introduction method has a problem in that the exhaust inlet is close to the throttle valve and negative pressure outlet.
When the recirculated exhaust gas flowed back, there was a risk of contaminating these. Furthermore, especially in the case of the intake passage structure of a fuel injection type engine, the mixing properties of the intake air are inferior to those of a mixture intake type engine, and it has been difficult to improve the distribution of exhaust gas. On the other hand, with the individual cylinder distribution system, there is no such fear, but since each communication port of the intake air pipe opens into one exhaust inflow chamber, the recirculation amount may be uneven due to the negative pressure of other cylinders. Furthermore, the intake inertia effect in the intake pipe was reduced, resulting in a decrease in output and torque.

(Means for solving the problem) The present invention aims to equalize the amount of exhaust gas recirculated to each cylinder in each cylinder distribution system, and also prevents a decrease in output and torque due to interference of negative pressure. There are four intake passages extending from one collective chamber, four cylinders connected to each intake passage, and two sets of connections in which each of the intake passages of two cylinders whose firing order is not consecutive is connected to each other through an independent exhaust outlet hole. A passage and
The present invention is characterized by providing a distribution path that communicates between intermediate portions of the two sets of communication paths, and an exhaust gas introduction path that communicates with the intermediate portions of the distribution paths.

(Embodiment) Fig. 1 shows a first embodiment of the present invention, in which 1 is a gathering chamber of an intake manifold, from which four intake passages 2a, 2b, 2c, and 2d are connected to cylinders numbered 1 to 4, respectively. Injectors 4a, 4b, 4c, and 4d are connected downstream of each intake passage.

The recirculating exhaust gas passes through the recirculation amount control valve shown only by the mounting seat 5, passes through the introduction passage 6 and the distribution passage 7 provided above the intake passage, flows into the two communication passages 8 and 9, and then flows into the exhaust outlet hole 10a. , 10b, 10c, 10d
The air flows from the air into each intake passage.

One of the communicating passages 8 is an intake passage 2a leading to the No. 1 cylinder and an intake passage 2a leading to the No. 4 cylinder.
d, and the other communication passage 9 communicates with an intake passage 2b leading to the No. 2 cylinder and an intake passage 2c leading to the No. 3 cylinder. 7 to form an E-shaped flow path.

Since the communication paths 8, 9 and the distribution path 7 are combined in this way, the ignition order can be changed to 1-3-4-2 or 1-3.
2-4-3, the next cylinder that starts its suction stroke at the end of the suction stroke of one cylinder always belongs to another communication path. For example, in an institution with a 1-3-4-2 order,
The exhaust gas first flows out from the exhaust outlet hole 10a of the communication passage 8, and then flows out from the exhaust outlet hole 10c of another communication passage 9.
then from the exhaust outlet hole 10 of the communication path 8.
d, and the exhaust gas outflow hole 10b of the communication path 9.
Even if the ignition order is 1-2-4-3, the fluid flows alternately through the communicating paths 8 and 9 in the same way. Note that 3 in the figure is a fuel pipe that guides fuel to the injector.

During engine operation, when air is being taken in through the intake passage that leads to one communication passage, even if the intake stroke begins in another intake passage, this intake passage always belongs to the other communication passage; two communication passages 8,
9 and the distribution path 7, the path between the two outlet ports with consecutive ignition orders is always a tortuous path, so the negative pressure caused by the start of intake will not affect the negative pressure of the preceding intake stroke. becomes extremely small.

Next, referring to FIGS. 2 and 3, we will explain the second aspect of the present invention.
An example will be explained.

In this embodiment, a gathering room 1, intake passages 2a, 2
The configuration of the intake manifolds such as b, 2c, 2d etc.
Although it is the same as the example, some changes have been made to the exhaust gas recirculation passage. In this embodiment, the introduction passage 12 passes under the No. 4 and No. 3 intake passages 2d and 2c, and passes through the rising edge 13 to the distribution passage 14 and the communication passage 1.
It is connected to 5 and 16. Then, both ends of one communication passage 16 are bent in the direction of the intake passage to form a bent passage 1.
7,18.

With this configuration, the exhaust gas flows upward through the riser 13 and is then distributed to the communication paths 15 and 16 through the distribution path 14, so that the directivity of the exhaust gas is canceled and it flows equally into both communication pipes. . Also,
By providing the meandering paths 17 and 18 in the communication path 16, the total length of the communication path 16 can be approximated to the length of the other communication path 15, and the behavior of the exhaust gas in both communication paths can be approximated to further increase the amount of exhaust gas recirculation. Can be equalized.

(Effect of the invention) As described above, the exhaust outflow hole from which the exhaust gas flows out in advance and the exhaust gas outflow hole at which the exhaust gas follows the outflow are in different communication paths and communicate through a bent communication path via the distribution path. The negative pressure caused by the start of intake in the preceding cylinder does not affect the negative pressure in the intake stroke of the preceding cylinder, and there is no risk of reducing intake efficiency and output. On top of that,
The movement of the exhaust gas flowing in from the introduction passage is equalized as it passes through the above-mentioned curved passage, and the exhaust gas is returned to each cylinder almost equally, which has the effect of making the combustion state uniform.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway plan view showing a first embodiment of the present invention, Fig. 2 is a similar plan view showing a second embodiment, and Fig. 3 is a cross-sectional view taken from Fig. 2. . In the figure, 2a, 2b, 2c, 2d...intake passages,
6,12...Introduction path, 7,14...Distribution path, 8,
9, 15, 16...Communication path, 10a, 10b, 1
0c, 10d...Exhaust outlet hole.

Claims (1)

[Scope of utility model registration request] There are four intake passages extending from one collective chamber, four cylinders connected to each intake passage, and two sets of connections in which each of the intake passages of two cylinders whose firing order is not consecutive is connected to each other through an independent exhaust outlet hole. 1. An exhaust gas recirculation path for an internal combustion engine, comprising a passage, a distribution path that communicates between intermediate portions of the two sets of communication paths, and an exhaust gas introduction path that communicates with the intermediate portion of the distribution path.