US 4,617,897 AGranted

Intake system for internal combustion engines

AssigneeMazda Motor Corporation

InventorsJunzo Sasaki, Mitsuo Hitomi, Ueda Kazuhiko

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Abstract

An intake system of an internal combustion engine is provided with a cross-sectional area changing means and a length changing means so that the cross-sectional area and/or the length of the intake system may be changed according to the change in the engine speed. Basically, at a high engine speed, the cross-sectional area is enlarged and the length is also enlarged to obtain an inertia supercharging effect at the high engine speed. By making the timing of changing the area different from that of changing the length, it is possible to maximize the inertia supercharging effect over a wide range of engine speeds. The cross-sectional area may be changed from SMALL to LARGE before the length is changed from LONG to SHORT, or after the length is changed from LONG to SHORT. The length may be changed stepwisely or continuously.

Claims27

Dependent claims

An intake system for internal combustion engines comprising a first intake passage extending between a combustion chamber of an engine and a surge tank, a second intake passage extending substantially in parallel to the first intake passage and connecting the combustion chamber with the tank, said second intake passage having a relatively short effective length, cross-sectional area changing means having a valve provided in the second intake passage, said valve having a close position at which said second intake passage is substantially closed and an open position, length changing means for changing the effective length between the combustion chamber and the tank in the first intake passage thereby altering the effective length of said first intake passage to a long state and to a short state, means for operating said cross-sectional area changing means adapted to shift said valve from the close position to the open position and means for operating said length changing means adapted to alter the effective length of said first intake passage from the long state to the short state, said means for operating said cross-sectional area changing means and said means for operating said length changing means being adapted to be actuated independently of each other according to the engine speed so as to form the following three conditions at different speeds:

(i) a first condition in which said first intake passage is in the long state, said valve is at the close position, and said combustion chamber is communicated with said tank through said first intake passage in the long state;
(ii) a second condition in which only one of said means for operating said cross-sectional area changing means and said means for operating said length changing means is actuated, said condition being formed during a higher engine speed operation than that of the first condition;
and
(iii) a third condition in which both said means for operating said cross-sectional area changing means and said means for operating said length changing means are actuated, said first intake passage is in the short state, and said valve is at the open position, said condition being formed during a higher engine speed operation than that of the second condition;
thereby changing the natural frequency of the intake system according to the engine speed to obtain an inertia supercharging effect at various engine speeds.

2 more elements

An intake system for internal combustion engines comprising an intake passage connected with an engine cylinder for introducing thereinto an intake gas, at least a part of said intake passage being composed of a first passage and a second passage parallel to each other, the upstream ends of said passages being connected to a tank to reflect a pressure wave generated in said cylinder and being transmitted through said passages;

valve means provided in said second passage selectively taking a first position to substantially close said second passage to stop transmission of said pressure wave in the passage and a second position to open the same;
first actuator means for changing over said valve means between the first position and the second position;
length changing means including a change-over member provided at least in said first passage for changing the substantial length of said passage between said cylinder and said tank;
and second actuator means operated independently of said first actuator means for actuating said change-over member between a long passage position and a short passage position, said first and second actuator means being adapted to be actuated according to the engine speed so as to form the following three conditions at different speeds:
(i) a first condition in which said first intake passage is at the long passage position, said valve means is at the first position, and the combustion chamber is communicated with the tank through said first intake passage at the long passage position;
(ii) a second condition in which only one of said first and second actuator means is actuated, said condition being formed during a higher engine speed operation than that of the first condition;
and
(iii) a third condition in which both said first and second actuator means are actuated, said first intake passage is at the short passage position, and said valve means is at the second position, said condition being formed during a higher engine speed operation than that of the second condition.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/693,297Filed 22 Jan 1985
Priority: JP 59-1064623 Jan 1984
Granted: 21 Oct 1986
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

F02F 1/425
Of intake channels: with a separate deviation element inside the channel
F02B 27/0215
Characterised by the charging effect: oscillating pipe charging, i.e. variable intake pipe length charging
F02B 27/0257
Plenum chambers; Resonance chambers or resonance pipes: rotatable plenum chambers
F02B 27/0263
Plenum chambers; Resonance chambers or resonance pipes: the plenum chamber and at least one of the intake ducts having a common wall, and the…