JP3170971B2 - Intake manifold for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake manifold for an internal combustion engine, and more particularly to a technique for reducing a back flow of EGR gas or the like to an auxiliary intake passage.

[0002]

2. Description of the Related Art Conventionally, in an internal combustion engine, N
An exhaust gas recirculation device that recirculates a part of exhaust gas to an intake system in order to suppress generation of Ox is known. The exhaust gas recirculation device includes an exhaust gas recirculation passage (EGR passage) that guides a part of exhaust gas of an internal combustion engine having a throttle valve in an intake system to an intake system, and an intake air recirculation passage provided downstream of the throttle valve. An exhaust gas recirculation valve that is driven using the pressure as a drive source to control the amount of exhaust gas recirculation, and one end of a tube that forms an exhaust gas recirculation passage is connected to a connection portion provided on an upstream outer wall of the intake manifold by bolts. The passage and the intake passage communicate with each other to guide a part of the exhaust gas (EGR gas) to the intake system (see Japanese Utility Model Application Laid-Open No. 58-1761).

In order to suppress the generation of unburned HC,
2. Description of the Related Art A blow-by gas reducing device that recirculates blow-by gas to an intake system and burns the gas in a combustion chamber is known. When the amount of EGR gas or blow-by gas introduced into the intake system increases, the gas may flow back to the auxiliary intake passage provided by bypassing the throttle valve, and the inner wall of the auxiliary intake passage or the auxiliary intake valve Then, carbon or the like in the gas adheres to the above, causing dirt or clogging.

In order to prevent such back flow of the EGR gas and the like into the auxiliary intake passage, there is a configuration in which the outlet of the auxiliary intake passage is inclined to the upstream side of the intake passage (see Japanese Utility Model Application Laid-Open No. 58-158139). Reference).

[0005]

However, in such a conventional intake manifold of an internal combustion engine, the amount of EGR gas or blow-by gas increases with respect to the amount of intake air, or the capacity of the collector volume is small. When the intake pulsation in the volume is large, the reverse flow rate of EGR gas or the like to the auxiliary intake passage increases, and carbon or the like in the gas adheres to the inner wall of the auxiliary intake passage or the auxiliary intake valve, thereby causing dirt or clogging. As a result, there is a problem that the effect of tilting the outlet of the auxiliary intake passage toward the upstream side of the intake passage is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and reduces the reverse flow rate of EGR gas or the like to an auxiliary intake passage, thereby reducing the carbon content in the gas on the inner wall of the auxiliary intake passage and the auxiliary intake valve. It is an object of the present invention to provide an intake manifold for an internal combustion engine in which dirt and clogging are prevented from being caused by adhesion of the like.

[0007]

In order to achieve the above object, according to the present invention, a groove which forms a part of an exhaust gas recirculation passage is formed on one joining surface of a collector part formed by dividing an intake manifold into two parts. In addition, a groove that forms a part of the auxiliary intake passage is formed at a position facing the groove on the other joint surface, and a gasket is interposed between the two grooves to form a two-layer auxiliary intake passage and an exhaust recirculation passage. Are formed apart from each other.

[0008]

According to this structure, when the amount of EGR gas or the like increases or the intake pulsation in the collector volume increases, the reverse flow of the EGR gas to the auxiliary intake passage tends to increase. However, when the amount of EGR gas increases, the heat capacity in the exhaust gas recirculation passage increases, so that heat is easily transmitted to the intake air in the auxiliary intake passage via the gasket. Therefore, the temperature of the intake air rises and the temperature difference between the intake air and the gas in the collector volume decreases, so that the EG to the auxiliary intake passage is
The reverse flow rate of R gas or the like decreases.

Further, when the intake pulsation in the collector volume increases, the auxiliary intake passage and the exhaust recirculation passage separated by the gasket are provided in parallel. Therefore, when the pressure in the collector volume increases due to the pulsation of the intake air in the collector volume, the pressures in the exhaust gas recirculation passage and the auxiliary intake passage also increase, and E
The reverse flow rate of GR gas or the like decreases.

Therefore, it is possible to prevent carbon or the like in the gas from adhering to the inner wall of the auxiliary intake passage or the auxiliary intake valve due to the backflow of the EGR gas or the like into the auxiliary intake passage, thereby preventing the dirt and clogging from occurring.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, an intake manifold according to an embodiment of the present invention will be described with reference to FIGS. That is, in the figure, in order to introduce outside air into a combustion chamber provided in the internal combustion engine 10, an intake manifold 11 is provided on a side surface of the internal combustion engine 10.
Is connected.

The intake manifold 11 extends substantially horizontally from a connection portion with an intake port of the engine 10 and is curved upward with an appropriate curvature. 11a is formed by inclining its upper surface 11b. Also, the upstream end flange portion 11a
On the lower inclined surface of the upper surface 11b, a groove 13 which forms a part of an exhaust gas recirculation passage communicating with a downstream of an exhaust passage (not shown) is formed. This groove 13 is provided with a connecting portion 1 provided at one end of a tube communicating with the exhaust passage on an upstream outer wall of the intake manifold 11 for suppressing generation of NOx in the exhaust gas.
1c, and communicates with the intake passage to guide a part of the exhaust gas (EGR gas) to the intake system.

A collector 12 common to all cylinders is connected to the upper surface 11b of the flange portion 11a.
The collector 12 has a rectangular parallelepiped box shape along the cylinder row direction of the engine 10 and has a volume sufficient to absorb suction pulsation. On the lower end face of the collector volume portion 12a at a position facing the groove 13 forming a part of the exhaust gas recirculation passage, a groove 14 forming a part of an auxiliary intake passage bypassing a throttle valve (not shown) is formed. I have. This groove 14 is provided with an inlet 14 provided on the outer wall of the collector 12.
a is introduced so as to be introduced in the downstream direction through the groove 14.

The upper surface 11b of the flange portion 11a and the lower end surface 12b of the collector volume portion 12a are formed by the two grooves 13,14.
By being in contact with a metal gasket 15 having high thermal conductivity therebetween, the intake manifold 11 and the collector volume 12a are communicated with each other, and the upper auxiliary intake passage 14 and the lower exhaust gas recirculation are formed. Passage 13 and gasket 1
5 so as to be formed apart from each other. That is,
The exhaust gas recirculation passage 13 and the auxiliary intake passage 14 perform heat transfer through the gasket 15, but do not directly flow the gas, and communicate with each other through the collector volume 12a.

A flange 12c is formed on one end wall of the intake collector 12.
Is connected to a throttle body in which a throttle valve (not shown) is installed. The throttle valve is opened and closed by a driver's operation of an accelerator pedal to control the amount of intake air. A mounting portion 11d for mounting a fuel injection valve (not shown) is formed near the connection end of the outer wall of the intake manifold 11 with the engine 10.
The fuel injection valve injects and supplies fuel toward an intake port of the engine 10.

Next, the operation of the present invention will be described with reference to FIG. When the amount of the EGR gas recirculated from the exhaust passage increases, the heat capacity in the exhaust recirculation passage 13 increases, so that heat is transmitted to the intake air in the auxiliary intake passage 14 through the gasket 15 having high thermal conductivity, and the heat is absorbed. Since the temperature of the air rises and the temperature difference between the air and the air in the collector volume 12a decreases, the reverse flow rate of the EGR gas to the auxiliary intake passage 14 decreases.

By arranging the exhaust gas recirculation passage 13 at a lower layer, the gas flow to the gasket 15 located thereabove is reduced.
Since the deposition due to carbon deposition in the GR gas is eliminated, a decrease in the thermal conductivity of the gasket 15 due to the carbon deposition can be prevented, and the above effect can be maintained for a long time. Further, when the intake pulsation in the collector volume 12a increases, the exhaust recirculation passage 13 forming the upper layer and the auxiliary intake passage 14 forming the lower layer separated by the gasket 15 are provided vertically in parallel. Therefore, the influence of the intake air pulsation in the collector volume 12a on the two passages 13 and 14 becomes equal. That is, when the pressure in the collector volume 12a increases due to the pulsation of the intake air in the collector volume 12a, the pressures in the exhaust gas recirculation passage 13 and the auxiliary intake passage 14 also increase. The flow rate decreases.

Accordingly, it is possible to prevent carbon and the like in the EGR gas from adhering to the inner wall of the auxiliary intake passage 14 and the auxiliary intake valve due to the backflow of the EGR gas and the like, thereby preventing the dirt and clogging from occurring.

[0019]

As described above, according to the present invention,
A groove that forms a part of an exhaust gas recirculation passage is formed on one joint surface of a collector portion formed by dividing an intake manifold into two parts, and a part of an auxiliary intake passage is formed at a position facing the groove on the other joint surface. Are formed, and a gasket is interposed between the two grooves to form the two-layer auxiliary intake passage and the exhaust recirculation passage separated from each other, so that the reverse flow rate of the EGR gas to the auxiliary intake passage is reduced. Accordingly, it is possible to prevent carbon and the like in the EGR gas from adhering to the inner wall of the auxiliary intake passage and the auxiliary intake valve, thereby preventing dirt and clogging.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a structure of an intake manifold of an internal combustion engine according to the present invention.

FIG. 2 is an exploded perspective view of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Internal combustion engine 11 Intake manifold 11a Flange part 11b Upper surface 11c Connection part 11d Mounting part 12 Collector 12a Volume part 12b Lower end face 12c Flange part 13 Groove (exhaust recirculation passage) 14 Groove (auxiliary intake passage) 15 Gasket

Claims (1)

(57) [Claims] 1. A groove which forms a part of an exhaust gas recirculation passage is formed on one joint surface of a collector portion formed by dividing an intake manifold into two parts, and an auxiliary member is provided at a position facing the groove on the other joint surface. An intake manifold for an internal combustion engine, wherein a groove forming a part of an intake passage is formed, and a gasket is interposed between the two grooves to form a two-layer auxiliary intake passage and an exhaust recirculation passage. .