JPH0236902Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an intake system for an internal combustion engine.

The purpose of this invention is to automatically increase the intake air amount under light loads of internal combustion engines with a simple structure.
This is an attempt to improve fuel efficiency.

Conventionally, inertial supercharging and turbo supercharging have been commonly used to increase the amount of intake air when an internal combustion engine is under light load. In this case, when the pressure inside the intake pipe becomes lower than atmospheric pressure, the amount of intake air cannot be increased.

In view of the above problems, the present invention is an intake system that introduces atmospheric air when the pressure inside the intake pipe, especially the inertial supercharging pipe, becomes lower than atmospheric pressure, thereby substantially increasing the amount of intake air. It provides:

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is an internal combustion engine, 2 is an intake manifold, and 3 is an inertial supercharging pipe communicating with the intake manifold 1. In FIG. In the present invention, on the wall near the connection point 4 between the intake manifold 2 and the inertial supercharging pipe 3,
An on-off valve 5 is provided which communicates with the atmosphere only when the pressure inside the inertial supercharging tube 3 becomes lower than atmospheric pressure.

This on-off valve 5 can take various forms, but as shown in FIG. 2, an example is as shown in FIG.
is provided inside the wall with this hole, and when the pressure inside the inertial supercharging tube 3 is above atmospheric pressure, the hole is closed, and when the pressure is below atmospheric pressure, the hole is opened with negative pressure. A reed valve may be used, or an inertial supercharging pipe 3
It may be a solenoid valve that is provided with a pressure sensor that detects the internal pressure and that opens and closes based on a signal from this pressure sensor.

In the figure, 6 is an exhaust turbine, and 7 is a compressor operated by the exhaust turbine 6, which constitutes a turbo supercharger.

According to the device of the present invention, as shown in FIG. 3, the pressure inside the inertial supercharging tube 3 is higher than atmospheric pressure when the internal combustion engine is under high, medium, and low loads;
Although the on-off valve 5 is in a closed state, there is a section where the pressure is lower than atmospheric pressure depending on the crank angle when the load is light. At this time, the on-off valve 5 opens and external air is introduced into the inertial supercharging pipe 3. As a result, the amount of intake air increases due to the introduced external air, and as shown in Figure 4, when there is no on-off valve, there is a section where the pressure inside the intake manifold is significantly lower than atmospheric pressure, as shown by the solid line. However, in the case of the present invention provided with the on-off valve 5, it was possible to bring the pressure in the section closer to atmospheric pressure as shown by the dotted line.

In this way, in the device of the present invention, an on-off valve is provided on the wall near the connection point between the intake manifold and the inertial supercharging pipe, which communicates with the atmosphere only when the pressure inside the inertial supercharging pipe becomes lower than atmospheric pressure. With a simple configuration, it has the practical benefit of increasing the amount of intake air during light loads and improving fuel efficiency.

[Brief explanation of the drawing]

Fig. 1 is a plan view of the present invention, Fig. 2 is an enlarged sectional view taken in the direction of the arrow in Fig. 1, Fig. 3 is a curve diagram showing pressure fluctuations under load in the inertial supercharging intake manifold, and Fig. 4 is FIG. 4 is a comparative curve diagram showing changes in intake manifold pressure at light loads between the device of the present invention and the conventional device. 1...Internal combustion engine, 2...Intake manifold, 3
...Inertial supercharging pipe, 4... Connection point between the intake manifold and the inertial supercharging pipe, 5... Opening/closing valve.

Claims (1)

[Scope of utility model registration request] In the intake manifold that communicates with the inertial supercharging pipe, an on-off valve that communicates with the atmosphere only when the pressure inside the inertial supercharging pipe becomes lower than atmospheric pressure is provided on the wall near the connection point between the intake manifold and the inertial supercharging pipe. An intake device for an internal combustion engine, characterized in that: