초록 ▼

In a supercharged engine, a bypass connected to the compressor delivery pipe (4) supplies the turbine with all the air which has not been absorbed by the engine. The bypass (4) is divided into a first branch which supplies combustive air to the primary region (10) of an auxiliary combustion chamber

In a supercharged engine, a bypass connected to the compressor delivery pipe (4) supplies the turbine with all the air which has not been absorbed by the engine. The bypass (4) is divided into a first branch which supplies combustive air to the primary region (10) of an auxiliary combustion chamber and a second branch which supplies diluting air to the secondary region of the aforementioned chamber and comprises first throttle means. The first branch has second throttle means (13) comprising coupled orifices (14, 15) formed respectively on an inner sleeve (16) and an outer sleeve (17) movable relative to one another. According to the invention, a radial clearance (a) is maintained between the sleeves (16, 17) irrespective of their respective temperatures. Third throttle means (45), having a zero minimum flow section, are provided upstream or level with the second means (13).

대표청구항 ▼

A supercharged internal combustion engine comprising a compressor supplying fresh air in parallel to the engine and to a bypass having an auxiliary combustion chamber and a turbine which receives the engine exhaust gases and the gases from the auxiliary combustion chamber and mechanically drives the

A supercharged internal combustion engine comprising a compressor supplying fresh air in parallel to the engine and to a bypass having an auxiliary combustion chamber and a turbine which receives the engine exhaust gases and the gases from the auxiliary combustion chamber and mechanically drives the compressor, the bypass being divided into two main branches, the first of which ends in a dilution region or “secondary region”downstream of the upstream part or “primary region”of the auxiliary combustion chamber and has first throttle means having a variable flow cross-section, whereas the second branch starts from a place on the first branch upstream of the first throttle means and opens into the primary region via second means for throttling the flow cross-section, the second throttle means comprising coupled passages having a variable common free cross-section and formed respectively in an internal and an external cylindrical means which are movable relative to one another, one of them at least partly bounding the primary region whereas the other at least partly bounds a cavity directly connected to the compressor outlet, at least one fuel injector opening into the primary region in the immediate neighbourhood of the aforementioned coupled passages, means being provided for correspondingly varying the flow rate of the fuel injector or injectors and also varying the flow rate of air entering the primary region via the common free section of the coupled passages, by moving the inner cylindrical means relative to the outer means, the engine being characterized in that: the second throttle means also have constant-section passages in parallel with the aforementioned coupled passages; the internal and external cylindrical means having radial dimensions such that, allowing for the thermal expansion coefficients of the material of which they are formed and their upper and lower operating temperatures, the radial clearance between them is always sufficient to prevent any lateral contact between the cylindrical means irrespective of the operating conditions of the auxiliary combustion chamber; and third throttle means having a variable flow section are mounted upstream of or at the coupled passages of the second throttle means, depending on the direction in which the air flows in the second branch of the bypass, and are actuated so that: (a) their minimum flow section is zero and (b) irrespective of the amounts to which the second and third throttle means are instantaneously opened, the flow section of the third throttle means is always either zero or much greater than the free section of the coupled passages of the second throttle means.