US 5,429,100 AGranted

Supercharged engine

AssigneeMazda Motor Corporation

InventorsTsuyoshi Goto, Kouichi Hatamura, Masatoshi Shoji

Life of this patent

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Abstract

The invention provides a supercharged engine including a supercharger and an intercooler disposed downstream of the supercharger. The engine has a geometric compression ratio equal to or higher than 8.5. The supercharger is an internal compression type mechanical supercharger having a pressure ratio higher than 1.8 wherein the pressure ratio is defined as a ratio of a pressure at an inlet opening to a pressure at an exit opening of the supercharger. Intake valve closing timing of the engine supercharger is in the range of 50 to 100 degrees in crank angle as measured from bottom dead center, and an overlapping period during which both intake and exhaust valves open is equal to or below 17 degrees in crank angle wherein the intake valve closing timing is defined as the timing when valve lift is equal to or less than 1 millimeter, and the overlapping period is to be measured on the basis of a valve lift of zero.

Claims7

Dependent claims

A supercharged engine comprising:

an intake valve;
an exhaust valve;
a supercharger;
and
an intercooler disposed downstream of said supercharger,
a geometric compression ratio of the engine being controlled to be at least equal to 8.5,
said supercharger comprising an internal compression type mechanical supercharger having a supercharging pressure ratio higher than 1.8 wherein said supercharging pressure ratio is defined as a ratio of a pressure at an inlet opening to a pressure at an exit opening of the supercharger,
an intake valve closing timing Y of said engine being in the range of 50 to 100 degrees in crank angle, measured from bottom dead center, and an overlapping period X, during which both of the intake and exhaust valves open, being no greater than 17 degrees in crank angle, wherein said intake valve closing timing is defined as a timing when valve lift is no greater than 1 millimeter and the intake valve closing timing Y is determined in relation with the overlapping period X according to the following equation:
Y.ltoreq.-2.5X-7.5
wherein:
Y is defined as the timing when valve lift is at least equal to 1 millimeter and is expressed in crank angle measured from bottom dead center;
and
X is a period during which both of the intake and exhaust valves open when valve lift is 1 millimeter.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/225,490Filed 8 Apr 1994 · continuation
Priority: JP 4-07805931 Mar 1992
Granted: 4 Jul 1995
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

F02D 13/0234
Variable control of the intake valves only: changing the valve timing only
F02B 33/36
With rotary pumps: of positive-displacement type
F02B 33/446
Passages conducting the charge from the pump to the engine inlet, e.g. reservoirs: having valves for admission of atmospheric air to engine, e.g.…
F02D 13/0261
During engine operation: controlling the valve overlap