JPH064352U - Internal combustion engine intake system - Google Patents

Abstract

(57) [Summary] [Objective] To provide a device in which a mixture with oil is not accumulated when soot is accumulated in the intake port to prevent intake. [Structure] Multiple intake ports 1 in one cylinder 3
The exhaust gas E for exhaust gas recirculation of the internal combustion engine provided with a and 1b and the blow-by gas B of the closed blow-by gas reducing device are introduced into one cylinder 3 from separate intake ports 1a and 1b. An intake device for an internal combustion engine configured as described above.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an intake system for an internal combustion engine, which mainly performs exhaust gas recirculation, that is, EGR, and closed PCV that returns unburned gas to the intake system without leaking to the outside in a multi-valve diesel engine having a plurality of intake ports. Is.

[0002]

[Prior art]

 In the conventional diesel engine shown in FIG. 3, the exhaust gas E is returned to the intake manifold 6 by the EGR pipe 5 in order to reduce the nitrogen oxides in the exhaust gas E discharged from the exhaust manifold 4, and the engine is In recent years, many have adopted a closed PCV that returns unburned gas leaking from the gap between the piston and cylinder during operation, that is, blow-by gas B, to the intake manifold 6 by the PCV pipe 7 without releasing it to the atmosphere. Has been done.

However, since blow-by gas B contains oil mist, when returned to the intake side in a mixed state with exhaust gas E of EGR, oil mist and soot in exhaust gas E are mixed, for example As shown in the cross-sectional view of FIG. 4, deposits 2 are generated in the intake port 1. The deposit 2 gradually grows and finally blocks the inlet port 1 and deposits on the head portion of the inlet valve. As a result, the amount of air in the cylinder is reduced and the air flow in the cylinder is changed. However, there is a problem in that combustion becomes unstable and engine performance deteriorates.

[0004]

[Problems to be solved by the device]

 The present invention has been made to solve the above-mentioned conventional problems, and provides an intake device for an internal combustion engine that can prevent fluctuations in the rotation of the engine without generating deposits in the intake port. It is intended for.

[0005]

In order to achieve the above object, an intake system for an internal combustion engine according to the present invention is provided with an exhaust gas for recirculating exhaust gas of an internal combustion engine in which one cylinder is provided with a plurality of intake ports. The blow-by gas of the closed blow-by gas reducing device is introduced into one cylinder from separate intake ports.

[0006]

[Work]

 According to the intake device having the above configuration, soot in exhaust gas and oil mist in blow-by gas are not mixed in the same intake port to generate a deposit.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a main part of a partial cross section showing an embodiment of an intake device for an internal combustion engine of the present invention, and FIG. 2 is a schematic enlarged view of a partial cross section of a cylinder of the internal combustion engine of FIG. First, a three-valve type or four-valve type internal combustion engine as in this embodiment, for example, a multi-valve diesel engine will be described. One cylinder 3 of the cylinder head 8 shown in FIG. , 1b, and one of the intake ports 1a contains the exhaust gas E of the EGR which is a part of the exhaust gas E from the exhaust port 9 shown in FIG. 2, and the other intake port 1b contains the blow-by gas B of the closed PCV. The air A for intake air is introduced into the branch pipes of the intake manifold 6, respectively. That is, as shown in FIGS. 1 and 2, the air A sucked from the intake pipe 10 is branched and supplied to a separate branch pipe of the intake manifold 6, but the air A for EGR sent from the EGR gas pipe 11 is supplied. Exhaust gas E and blow-by gas B sent from the blow-by gas pipe 12 are separately sent and introduced into the same cylinder 3 from the respective intake ports 1a, 1b.

As a result, the soot in the exhaust gas E does not combine with the oil mist in the blow-by gas B, so that the deposit 2 is not generated and the engine performance is not deteriorated. Further, since an appropriate amount of EGR exhaust gas E can be distributed to each cylinder 3, the combustion products of each cylinder 3 also have a uniform value. This means that the same combustion state can be obtained in each cylinder 3, so that an engine with no rotation fluctuation can be provided. Further, since the deterioration state of each cylinder 3 is also uniform, it is possible to provide a favorable engine as a whole.

[0009]

[Effect of device]

 In the intake device for an internal combustion engine according to the present invention, the exhaust gas for exhaust gas recirculation of the internal combustion engine, in which a plurality of intake ports are provided in one cylinder, and the blow-by gas for the closed blow-by gas returning device are separated. It is configured to be introduced into one cylinder from the intake port.

Therefore, soot in the exhaust gas for EGR does not mix with the oil mist in the blow-by gas to generate deposits in the intake port, so that intake is not hindered and engine output Of the exhaust gas and rotation fluctuation are prevented, and further, the increase of smoke in the exhaust gas can be prevented.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional plan view showing an embodiment of an intake device for an internal combustion engine according to the present invention.

FIG. 2 is a schematic enlarged view of a cylinder partial cross section of the internal combustion engine of FIG.

FIG. 3 is a schematic side view of a conventional internal combustion engine.

FIG. 4 is a front cross-sectional view showing deposits formed in the intake port of FIG.

[Explanation of symbols]

1a, 1b Intake port 3 Cylinder 6 Intake manifold 10 Intake pipe 11 EGR pipe B Blow-by gas E Exhaust gas

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location F02M 35/10 Z 9247-3G

Claims (1)

[Scope of utility model registration request] 1. An exhaust gas for exhaust gas recirculation of an internal combustion engine, wherein a plurality of intake ports are provided in one cylinder, and blow-by gas of a closed blow-by gas reducing device,
An intake system for an internal combustion engine configured to be introduced into one cylinder from separate intake ports.