JPH0315808Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial field of application The present invention relates to an internal combustion engine equipped with an exhaust gas recirculation device, particularly an intake pipe configured to prevent combustion products (deposits) from adhering to the exhaust gas inlet. It concerns internal combustion engines.

Conventional technology In a normal engine, when the piston reciprocates inside the cylinder, the piston ring acts as a kind of pump, so unburned hydrocarbons (HC) enter the engine crankcase through the gap between the piston ring and the cylinder wall. . This unburned HC (generally referred to as blow-by gas) pollutes the atmosphere if released into the atmosphere, so it is normally led to the cylinder head of the engine, and from the cylinder head it is introduced into the intake manifold where it is mixed with intake air. This device is generally called a PCV (positive crankcase ventilation) device.

On the other hand, engines recirculate a portion of the exhaust gas back into the intake system to purify nitrogen oxides (NO _x ) in the exhaust gas. In such exhaust gas recirculation (EGR) devices, as mentioned above, in those that introduce oil vapor or blow-by gas from the crankcase or cylinder head into the intake pipe, the oil vapor or the like is transferred to the outlet of the EGR pipe. (EGR gas inlet of the intake pipe), and when the EGR gas comes into contact with the attached oil, the temperature of the EGR gas decreases, and combustion products (deposits) such as carbon in the EGR gas may accumulate. This means that
This can occur not only in engines equipped with PCV devices, but also in engines equipped with turbochargers.

In order to reduce the accumulation of deposits, the outlet end of the EGR pipe protrudes into the intake pipe (Utility Model Application No. 56-88933, Utility Model Application No. 58-116748).
(No. 58-65922), a guide that guides blow-by gas to the downstream side of the EGR pipe outlet end, where the EGR gas inlet and PCV passage opening are arranged symmetrically with respect to the throttle valve axis (Japanese Patent Application Laid-open No. 1983-65922). (Utility Model Application No. 56-88934), or one with a PCV pipe protruding into the intake pipe (Utility Model Application No. 58-88934).
33713), with the EGR gas inlet located downstream of the branched part of the intake pipe (Utility Model Application No. 179322, 1983)
etc. have been proposed.

Problems to be Solved by the Invention The present invention simplifies the installation of the EGR valve in engines equipped with an exhaust gas recirculation (EGR) device, simplifies the EGR piping, and connects the EGR gas inlet from upstream to the EGR gas inlet. The purpose of the present invention is to provide an internal shape of an intake pipe that can prevent flowing oil vapor and the like from flowing in, prevent deposits from accumulating, and secure the required amount of EGR.

Means for Solving the Problems According to the present invention, in an internal combustion engine equipped with an exhaust gas recirculation device that introduces a part of exhaust gas from an inlet to an intake pipe through an EGR passage having an EGR valve, An inlet is provided in the upper part of the intake pipe, and the EGR valve is provided in a position in the EGR passage adjacent to the inlet, and at least
A portion of the EGR passage up to the EGR valve is formed integrally with a wall portion of the intake pipe and extends in a direction substantially perpendicular to a flow direction of intake air in the intake pipe, and a portion of the EGR passage between the intake pipe and the EGR passage. an exhaust gas recirculation device, characterized in that a folded part is formed in the vicinity of the inlet of a partition part that separates the partition part, and an internal angle between the partition part and the inner wall of the intake pipe facing the part is 90 degrees or less. An internal combustion engine is provided.

Embodiments This invention will be described below based on drawings showing embodiments. First, in FIG. 4, 1 is the engine body, 2 is an intake pipe (intake manifold), and 3 is an exhaust pipe. The intake pipe 2 and the exhaust pipe 3 communicate with each other via an EGR pipe 4 and an EGR valve 5.
The EGR valve 5 opens and closes a valve port (inflow port) 5c communicating with the intake pipe 2 by a valve element 5b actuated by the height of the engine intake negative pressure and a spring 5a. Then, EGR gas is introduced into the intake pipe 2 from the EGR gas inlet 10. On the upstream side of the EGR gas inlet 10, the inside of the intake pipe 2 communicates with the inside of the cylinder head cover 6 through a PCV pipe 7. 9 is an air cleaner connected to intake pipe 2 by hose 8.
is connected to.

FIG. 5 is a top plan view of the engine 1 mounted on a vehicle, FIG. 6 is an enlarged plan view of the portion indicated by the symbol in FIG. 5, and FIG. FIG. 7 is a sectional view taken along line A-A in FIG. 6 of an engine equipped with an EGR device. In this way, conventionally, the EGR gas inlet 1 was installed on the side of the intake pipe 2.
0, the oil vapor flowing from the PCV device or turbocharger etc. flowing from upstream cannot be properly separated from the EGR gas flowing into the intake pipe 2, and as mentioned above, the EGR gas inlet 10 Deposits were easily attached to the surrounding area.

FIGS. 1 and 3 are cross-sectional views corresponding to the line A-A in FIG. 6, showing each embodiment near the EGR gas injection part of the intake pipe 2 of an engine equipped with the EGR device of the present invention. It is. In these examples,
The EGR valve 5 is attached to the side of the intake pipe 2, similar to the conventional EGR device (Fig. 7).
The arrangement of the EGR gas outflow passage 12 from the EGR valve 5 and the EGR gas inlet 10 to the intake pipe 2 is different from that of the conventional EGR device (FIG. 7).

In the embodiment shown in FIGS. 1 and 2, the EGR
The gas outflow passage 12 is molded with a core (not shown) when molding the intake pipe 2, and
installed inside. That is, as shown in FIG. 1, the EGR gas passage 12 integrated with the intake pipe 2 enters the inside of the intake pipe 2 from the side of the intake pipe 2,
is guided to the upper part of the intake pipe 2. The EGR gas inlet 10 at the upper part of the intake pipe 2 opens into the intake pipe 2 . It is preferable that the EGR gas passage 12 has a rectangular cross-section so that it can easily increase the cross-sectional area in a narrow installation space (second
(see figure). Further, it is preferable that the EGR gas inlet 10 be made as wide as possible so that the deposit can be easily peeled off. At the upper end of the partition wall 13, that is, at the edge of the EGR gas inlet 10 on the partition wall 13 side, a folded portion 14 as shown is provided. It is desirable that the folded portion 14 has a width w of 5 to 10 mm and an internal angle α between it and the partition wall 13 of 90° or less. Further, the partition wall 13 includes a bottom wall 2a of the intake pipe 2 that forms a substantially horizontal surface.
It is also desirable that the internal angle β (inside angle of the intake pipe 2) with respect to the intake pipe 2 is also 90° or less. The partition wall 13 and the folded portion 14 prevent oil components from creeping upward along the inner wall of the intake pipe 2.

In the embodiment shown in FIG.
It is installed integrally with the intake pipe 2 from the upper side of the intake pipe 2.
It protrudes into the inside of. Therefore, the EGR gas inlet 10 is located at a position that projects slightly (5 to 10 mm) downward from the inner upper wall 2b of the intake pipe 2, and prevents oil components from flowing into the EGR gas inlet 10. Further, the side wall portion 2c of the intake pipe 2 along which the EGR gas passage 12 is
2, and is recessed inward along the side wall 2 of the intake pipe 2.
Since there is a level difference between the side wall 2d and the side wall 2d, the oil component flowing along the side wall 2d is also blocked by this level difference part 2c and is prevented from flowing into the EGR gas injection port 10.

In both of the above two embodiments, the EGR passage is connected to the intake pipe 2.
extends in a direction perpendicular to the flow direction of the intake air, and opens into the intake pipe in the direction perpendicular to the flow direction of the intake air. Further, a partition wall portion 13 separating the intake pipe 2 and the EGR passage portion 12,
2c is configured such that the internal angle between it and the inner wall of the intake pipe 2 facing it is 90° or less.

Effects of the invention According to the invention, the EGR gas inlet 10 is provided at the upper part of the intake pipe 2, and as described above, the structure is such that oil components etc. do not easily flow into the EGR gas inlet 10. Even if the EGR valve is installed on the side of the intake pipe, the PCV
Even if oil components are included in the gas or the supercharged intake air of a turbocharger, the EGR gas joins with these oil components after sufficiently mixing with fresh air, so deposits containing carbon particles and impurities can form inside the intake pipe. is not generated or deposited, and therefore a sufficient amount of EGR can be ensured.

In addition, in this invention, the EGR valve is installed in a position close to the EGR gas inlet, that is, near the intake pipe, so this installation is easy, and the EGR passage from the EGR valve installation part to the EGR gas inlet is Since the part is formed integrally with the intake pipe,
The piping of the EGR passage becomes simple and the cost can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing one embodiment of the present invention, and is a sectional view corresponding to the line A-A in FIG. 6, and FIG.
3 is a sectional view corresponding to line A-A in FIG. 6 of another embodiment of the present invention, and FIG. 4 is a schematic diagram showing the entire engine equipped with an EGR device. Fig. 5 is a plan view of the same engine seen from above, Fig. 6 is an enlarged plan view of the part indicated by the symbol in Fig. 5, and Fig. 7 is a plan view of the engine seen from above.
The figure is a sectional view corresponding to line A-A in FIG. 6 showing the vicinity of the EGR gas injection port of a conventional EGR device. 2...Intake pipe (intake manifold), 5...EGR
Valve, 10...EGR gas inlet, 12...
EGR gas passage.

Claims (1)

[Scope of utility model registration request] EGR with EGR valve 5 to transfer part of the exhaust gas
In an internal combustion engine equipped with an exhaust gas recirculation device that introduces exhaust gas from an inlet 10 into an intake pipe 2 via a passage,
The inlet 10 is provided at the upper part of the intake pipe 2, and the
The EGR valve 5 is placed close to the inlet 10.
Provided at the position of the EGR passage, at least a portion 12 of the EGR passage from the inlet 10 to the EGR valve 5 is integral with the wall of the intake pipe 2 and substantially perpendicular to the flow direction of intake air in the intake pipe 2. The intake pipe 2 is formed to extend in the same direction as the intake pipe 2.
Partition wall parts 13, 2c that separate the EGR passage part 12
Exhaust gas recirculation characterized in that a folded part 14 is formed in the vicinity of the inlet 10, and the internal angle between the partition wall parts 13, 2c and the inner wall of the intake pipe 2 facing thereto is 90 degrees or less. Internal combustion engine with equipment.