JPH04279754A - Egr gas deposit reducing manifold - Google Patents

Abstract

PURPOSE:To prevent the generation and the accumulation of a tar-form deposit by avoiding mixing an exhaust gas recirculating gas and a blowby gas in a suction manifold, but leading in them to the cylinders through different passages in the suction manifold respectively. CONSTITUTION:While an engine furnishes two suction valves 3 per one cylinder, for example, two suction ports 2 are provided corresponding to them in an engine block 5. And corresponding to the suction ports 2, a suction manifold 1 is branched into two suction manifold branch pipes 1a and 1b at the part to connect to the engine block 5, being connected to suction ports 2. In this case, the PCV gas (blowby gas) and the EGR gas are not led in to the suction manifold 1 directly but into a PCV gas pipe 8 and an EGR gas pipe 9 provided parallel to the axial line of the suction manifold respectively. And they are led in the suction manifold branch pipes 1a and 1b separated each other, from a PCV gas suction hole 18 and an EGR gas suction hole 19.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for reducing EGR gas deposits in the intake manifold of an engine equipped with an exhaust gas recirculation system and a blow-by gas reduction system.

0002

[Prior Art] Conventionally, the above-mentioned exhaust gas recirculation device (EG
In an engine equipped with both a blow-by gas reduction system (PCV system) and a blow-by gas reduction system (PCV system), as an example, an engine having two intake valves 3 per cylinder as shown in FIG. ), the intake gas is drawn into the intake manifold 1 through the intake port 2 and the intake valve 3, and flows into the cylinder 4 in the cylinder block 5. Exhaust gas (hereinafter referred to as EGR gas) taken out from the crankcase or cylinder head cover (not shown) is inhaled through the EGR valve 7, and blow-by gas (hereinafter referred to as EGR gas) taken out from the crankcase or cylinder head cover (not shown) is
(hereinafter referred to as PCV gas) is inhaled, and as shown in the figure, these three
Seed gases mix in the intake manifold 1 and enter the intake port 2.
, and is taken into the cylinder 4 via the intake valve 3.

0003

[Problem to be Solved by the Invention] In the above engine, carbon in the EGR gas and oil in the PCV gas from the crankcase or head cover mix, and this forms a tar-like deposit D. It accumulates on the walls of the intake manifold 1 and the intake ports 2, as shown by hatching. Due to the accumulation of this deposit D, the cross-sectional area of the intake passage becomes small or blocked,
There is a problem in that the flow of intake gas deteriorates, resulting in deterioration of engine performance and reliability.

[0004] In view of the above problems, in the present invention,
It is an object of the present invention to provide a means for reducing the accumulation of this deposit on the walls of the intake manifold and intake ports.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an engine equipped with both an exhaust gas recirculation device and a blow-by gas reduction device.
An EGR gas deposit reduction manifold characterized in that the exhaust gas and the blow-by gas are configured so that they flow through separate passages in the intake manifold and flow into the cylinders of the engine without being mixed in the intake manifold. I will provide a.

[0006]

[Operation] EGR gas entering the intake manifold and PCV
The gas flows through separate passages in the intake manifold and flows into the cylinder, and the two do not mix together in the intake manifold. This prevents the carbon in the EGR gas and the oil in the PCV gas from mixing and forming tar-like deposits that accumulate on the wall of the intake manifold.
GR gas deposit is reduced.

[0007]

[Embodiment] An embodiment of the present invention will be explained based on the drawings. FIG. 1 shows a first embodiment. This engine has two intake valves 3 (31, 3
2), and intake ports 2 (21, 22) are provided in the engine block 5 corresponding to each intake valve. Corresponding to these two intake ports 21 and 22, the intake manifold 1 is divided into two manifold branch pipes 1a and 1 for each cylinder at the part connecting to the engine block 5, respectively.
b and is connected to the intake ports 21 and 22.

The PCV gas and EGR gas do not directly enter the intake manifold 1 as in the case of FIG. 5, but as shown in the figure, the PCV gas pipe 8 and the EGR gas pipe are arranged parallel to the axis of the intake manifold, respectively. PCV gas intake holes 18 introduced into the PCV gas inlet 9 and bored in the branch pipes 1a and 1b,
The EGR gas enters separate intake manifold branch pipes 1a and 1b from the EGR gas intake hole 19, and flows into the cylinder 4 via intake ports 21 and 22 and intake valves 31 and 32.

[0009] In this way, the flows of EGR gas and PCV gas in the intake passage are completely separated, so that the EGR gas and PCV gas do not mix in the intake manifold passage, and therefore carbon Because of the oil, it does not become tar-like and is less likely to accumulate on the manifold wall.

FIG. 2 shows a second embodiment. This engine also has two intake valves 3 per cylinder, and in this case, as shown in the figure, the intake manifold 1 is divided into two at the inlet and branched into two intake manifold branch pipes 11 and 12. EGR gas entering from the EGR valve 7 flows into one branch pipe 11, and PCV gas flows into the other branch pipe 12, and the intake gas flowing through each branch pipe is sent to separate intake ports 21, 22 and The air flows into the cylinder 4 through the intake valves 31 and 32.

A third embodiment is shown in FIGS. 3 and 4. This embodiment shows a case in which each cylinder has one intake port 2 and one intake valve 3, and in this case, the intake manifold 1
The inside of the intake passage is divided into two by a partition wall 6 into intake passages 13 and 14. EGR gas entering from the EGR valve 7 flows into one of the divided intake passages 13, and the PC flows into the other intake passage 14.
V-gas flows, and both of them meet at the intake port 2 in the engine block 5 and flow together with the intake gas into the cylinder 4 through the intake valve 3. 3(a) is a plan view of this device, (b)
) shows its side view, and FIG. 4 shows its perspective view. Also, the cross-sectional area of the intake manifold 1 at this time is larger than that of the conventional one.
Since it becomes smaller due to the partition wall 6, it is made larger by that amount so that the flow rate of intake gas in the intake manifold 1 does not become smaller.

According to the above three embodiments, the EGR gas and PCV gas flowing in the intake manifold 1 are separated and flowed to each intake port 2, thereby reducing the accumulation of carbon deposits in the intake manifold 1. Something happens.

[0013]

[Effects of the Invention] By implementing the present invention, the following effects can be achieved. (1) EGR gas and PC in the engine intake manifold
Mixed flow with V gas is eliminated, and the accumulation of carbon deposits on the wall surface of the intake manifold is reduced.

(2) By reducing the accumulation of deposits, the cross-sectional area of the intake passage will not become small or clogged, and deterioration in engine performance will be prevented.
Its reliability also improves.

[Brief explanation of the drawing]

FIG. 1 shows a first embodiment of the present invention, and (a) is a partially sectional plan view thereof. (b) is a BB sectional view of (a).

FIG. 2 is a partially sectional plan view of the second embodiment.

FIG. 3 shows a partial sectional view of a third embodiment, in which (a) is a plan view thereof and (b) is a side view thereof.

FIG. 4 is a partially cross-sectional perspective view of the third embodiment.

FIG. 5 is a partially sectional plan view of an intake passage equipped with a conventional EGR and PCV system.

[Explanation of symbols]

1...Intake manifold 1a, 1b...Intake manifold branch pipe 2, 21, 22...Intake port 4...Cylinder 6...Bulkhead 8...PCV gas pipe 9...EGR gas pipe 11, 12...Intake manifold branch pipe 13, 14...Intake passage

Claims (1)

[Claims] 1. In an engine equipped with both an exhaust gas recirculation device and a blow-by gas reduction device, the exhaust gas and the blow-by gas are not mixed in the intake manifold, but each flows through separate passages in the intake manifold. An EGR gas deposit reduction manifold configured to flow into a cylinder of an engine.