JPH0540247Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to an intake system for an internal combustion engine, which has a pair of throttle valves, and has an intake passage downstream of the throttle valves separated into two independent systems.

BACKGROUND ART FIGS. 4 and 5 show an intake system for a V-type six-cylinder internal combustion engine 31 as an example of the configuration of a conventional intake system. This intake device has a collector section 32 between both banks, and a throttle valve 34 is interposed in an intake passage 33 connected to one end of the collector section 32. The tip of an exhaust gas recirculation (hereinafter abbreviated as EGR) gas passage 35 is open, and the tip of an auxiliary air passage 36 that bypasses the throttle valve 34 is open to the collector section 32. A partition wall 37 is provided in the collector section 32 to avoid interference between the intake air of each cylinder, and a connector passage 32a communicating with the cylinder groups #1, #3, and #5, and a connector passage 32a communicating with the cylinder groups #2, #5, It is separated from a connector passage 32b communicating with cylinder groups #4 and #6. (Refer to Japanese Utility Model Application Publication No. 59-196546) Problems to be Solved by the Invention However, in the intake system in which the EGR gas passage 35 is opened downstream of the throttle valve 34 as described above, recirculation exhaust gas is generated due to the pulsation of intake air. It may spread to the throttle valve 34 side, and there is a risk that the throttle valve 34 may become stuck due to adhesion of carbon, etc. in the exhaust gas, or that various negative pressure outlets near the throttle valve 34 may be blocked. It was hot.

In addition, in the configuration shown in FIGS. 4 and 5 above, the intake air of both cylinder groups joins upstream of the collector section 32, but in order to further enhance the dynamic effect of intake air, both cylinder groups are connected upstream of the throttle valve 34. If an attempt is made to separate the intake system into two independent systems, it will likely be difficult to evenly distribute the recirculated exhaust gas.

Note that these problems similarly occur even when blow-by gas is introduced into the intake system.

Means for Solving the Problems This invention has a pair of collector parts that are independent of each other, and has independent intake passages upstream of the collector parts, and at least the upstream portions of the pair of intake passages. In an intake system for an internal combustion engine, in which throttle valves are arranged adjacent to each other in parallel and are fixed to a common rotational shaft, an inner wall surface downstream of the throttle valves and adjacent to each other in the intake passage is provided. , blow-by gas or EGR
The present invention is characterized in that gas passages such as gas are opened approximately symmetrically, and an auxiliary air passage that bypasses the throttle valve is opened approximately symmetrically upstream of and near the opening of the gas passage.

Function In the above configuration, the air flow ejected from the auxiliary air passage into the intake passage acts as a type of air curtain, and prevents the EGR gas etc. supplied from the gas passage from diffusing upstream. In addition, EGR gas, etc. is evenly supplied to both intake passages through gas passages that are opened approximately symmetrically, and is mixed well with the air ejected from the auxiliary air passage before being sent to the collector section. evenly distributed.

Embodiment FIGS. 1 and 2 show an embodiment of this invention. This embodiment also shows an example applied to a V-type six-cylinder internal combustion engine 1, and a pair of collector parts 2, 3 are disposed between both punctures, and the collector parts 2, 3 and the intake air Introduction passage 4
are connected by a pair of intake passages 5 and 6.

The collector sections 2 and 3 are configured independently from each other, one communicating with the cylinder groups #1, #3, and #5 via the branch section 7, and the other communicating with the cylinder groups #2, #4, and #5.
It communicates with the #6 cylinder group via a branch portion 8. In this embodiment, both collector parts 2 and 3 are integrally cast. In addition, the intake passages 5 and 6 are
The upstream portions connected to the intake air introduction passage 4 are formed parallel to each other and adjacent to each other, and are branched into two on the downstream side, with their respective tips connected to different ends of the collector portions 2 and 3. ing. Throttle valves 10 and 11 fixed to a common rotating shaft 9 are respectively disposed at upstream portions that are parallel to each other as described above. That is, the throttle valves 10, 11
The downstream side of the cylinder is completely separated for each cylinder group to prevent intake air interference and improve dynamic effects.

Reference numeral 12 denotes an EGR gas passage connected to the exhaust passage 13 of the internal combustion engine 1, the tip of which is connected from the lower surface side to a bifurcated branch portion downstream of the throttle valves 10, 11 of both the intake passages 5, 6; Here, as shown in FIG.
It opens at 6. That is, they are opened symmetrically on the inner wall surfaces of the intake passages 5 and 6 adjacent to each other. Note that 14 is an exhaust gas recirculation control valve that opens and closes the EGR gas passage 12.

Reference numeral 15 denotes an auxiliary air passage for idle rotation speed control that is provided to bypass the throttle valves 10 and 11, and its tip is connected to the bifurcated branch of both intake passages 5 and 6 from the bottom side. Here, it branches into a T-shape and opens symmetrically into intake passages 5 and 6, respectively. The opening 1 of this auxiliary air passage 15
6 and 17 are the openings 1 of the EGR gas passage 12 mentioned above.
8 and 19, this is a flow control solenoid valve slightly interposed in the auxiliary air passage 15, which is constantly opened and closed at, for example, about 160 Hz, and controls the auxiliary air flow rate by changing its ON time ratio. are doing.

In this embodiment, most of the intake passages 5 and 6 are cast integrally with the collector parts 2 and 3.
Only the portions near the throttle valves 10 and 11 are constructed separately as a throttle chamber 21.

In the above configuration, the exhaust gas that has flowed through the EGR gas passage 12 flows into the intake passages 5 and 6 through the openings 18 and 19, but the opening 16 of the auxiliary air passage 15 located upstream from this flows into the intake passages 5 and 6. , 17 acts as a kind of air curtain across the intake passages 5, 6, so that it does not diffuse toward the throttle valves 10, 11 even if it receives pulsation of intake air. Therefore, contamination around the throttle valves 10, 11 due to exhaust gas is extremely reduced.

Furthermore, since the EGR gas passage 12 is symmetrically branched as shown in FIG. 3, exhaust gas flows equally into the intake passages 5 and 6. And opening 18,1
After the inflow from 9, the adjacent opening 16,1
Because it mixes well with the auxiliary air jetted out from 7,
Exhaust gas is distributed very evenly to each cylinder.

On the other hand, the EGR gas passage 12 and the auxiliary air passage 15
By forming the distal end portions of the intake passages 5 and 6 at the bifurcated branch portions of the intake passages 5 and 6 as described above, there is no need to provide complicated external piping, and even with an extremely simple configuration, it is possible to connect both the intake passages 5 and 6. Exhaust air and auxiliary air can be supplied evenly.

Effects of the invention As is clear from the above explanation, the intake system for an internal combustion engine according to this invention can prevent EGR gas, blow-by gas, etc. from adhering to the vicinity of the throttle valve.
Malfunction of the throttle valve due to this will not occur. Furthermore, it is possible to achieve extremely good distribution of EGR gas and the like to each cylinder, which tends to be a problem when two systems downstream of the throttle valve are separated and independent.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of this invention, Fig. 2 is a sectional view taken along the - line, Fig. 3 is a sectional view taken along the - line, and Fig. 4 shows an example of the conventional configuration. The sectional view shown in FIG. 5 is a sectional view taken along the - line. 2, 3... Collector part, 5, 6... Intake passage,
10, 11...throttle valve, 12...EGR gas passage,
15...Auxiliary air passage.

Claims (1)

[Scope of utility model registration request] It has a pair of collector parts that are independent from each other, and has independent intake passages upstream of the collector parts, and at least the upstream parts of the pair of intake passages are formed parallel to each other and adjacent to each other, and there is a common In an intake system for an internal combustion engine, in which throttle valves are respectively disposed, each being fixed to a rotation shaft of the intake passage, an inner wall surface downstream of the throttle valves and adjacent to each other in the intake passage includes:
Gas passages for blow-by gas or exhaust recirculation gas are opened approximately symmetrically, and an auxiliary air passage that bypasses the throttle valve is opened approximately symmetrically upstream of and near the opening of the gas passage. Intake system for internal combustion engines.