Power plants – Fluid motor means driven by waste heat or by exhaust energy... – With supercharging means for engine
Reexamination Certificate
2000-05-11
2001-08-07
Denion, Thomas (Department: 3748)
Power plants
Fluid motor means driven by waste heat or by exhaust energy...
With supercharging means for engine
C123S559100, C415S204000, C415S206000, C415S164000
Reexamination Certificate
active
06269643
ABSTRACT:
The invention relates to an internal combustion engine/turbocharger system in accordance with the precharacterizing clause of claim
1
.
Internal combustion engine/turbocharger systems of the abovementioned type are known, for example, from DE 42 32 400 C1. In this case, an annular insert can be slid axially into the region in the form of an annular nozzle starting from the flow duct and opening onto the turbine rotor, this insert being designed in part as a guide vane system and having guide vanes at different angles of incidence, which are brought into effect as a function of the axial setting of the annular insert. The annular insert, which is formed by a displaceable tubular sleeve component, has an axial region which is moved into axial overlap, as a shut-off device, with the inlet region in the form of an annular nozzle, for the braking mode and the cross section of passage of which is dimensioned in such a way that, acting as a restrictor for the exhaust gas, it defines the narrowest cross section of flow—invariable in braking mode—at the transition to the turbine rotor. In this way, it is possible to achieve high braking powers, but there are difficulties in implementing these braking powers at low thermal loading of the internal combustion engine, especially in a suitable relationship with the engine speed and over a sufficiently wide engine-speed band, resulting overall in difficulties in finding an appropriate internal combustion engine/turbocharger configuration which meets these requirements.
The invention is intended to provide an internal combustion engine/turbocharger system which will make possible the high braking powers desired for the braking mode in a suitable relationship with the engine speeds significant for the driving mode, while combining this with relatively low thermal loads.
This is achieved in internal combustion engine/turbocharger systems by a design in accordance with the features of Claim
1
, according to which the main parameters of the turbine are defined in such a way, in relation to the total displacement of the internal combustion engine, that maximum braking powers are made possible with comparatively low thermal loading of the internal combustion engine and in a sufficiently broad engine-speed range suitable for the operation of commercial vehicles.
In this context, the following relation applies:
TBF
=
A
T
×
D
T
V
H
where A
T
denotes the cross section of flow exposed by the shut-off device acting as a fixed restrictor and the blow-off valve in the exhaust path to the turbine at maximum braking power, D
T
denotes the inlet diameter of the turbine rotor and V
H
denotes the displacement of the internal combustion engine. TBF forms a turbo-braking factor, which, in the context of the invention, is less than 0.005 (5%) and is preferably 0.001 to 0.003 (1-3%).
Based on maximum braking power as the design point, the cross section of flow exposed in the exhaust path to the turbine at maximum braking power in the context of the invention is formed by a cross-sectional component exposed at the transition to the turbine by the shut-off device, covering a lower engine-speed range, and a variable cross-sectional component, which is larger than that for the design point, namely maximum braking power, and is formed by the outflow cross section exposed by the blow-off valve. In the context of the invention, the ratio of the additional, variable cross-sectional component, which increases towards the maximum braking power and corresponds to the outflow cross section exposed by the blow-off valve, to the cross-sectional component exposed by the shut-off device, is greater than 0.2 for the design point, namely maximum braking power, and is preferably in the range between 0.2 and 1. With a small ratio, the braking power in the lower engine-speed range is relatively low and rises relatively steeply in the upper engine-speed range; with a large ratio, a higher braking power is obtained in the lower engine-speed range, with a less steep rise in the braking power towards the point of maximum braking power as the design point, in comparison with smaller ratios. Based on the speed band of the engine, the upper speed range, in which the additional, variable outflow cross section defined by the blow-off valve is exposed, begins at about ⅔ to ¾ of the speed at maximum braking power, the speed at maximum braking power lying within a range which is about ¼ to ⅓ times greater than the rated speed of the internal combustion engine, i.e. the speed at the maximum power of the internal combustion engine.
REFERENCES:
patent: 4474006 (1984-10-01), Price et al.
patent: 4617799 (1986-10-01), Todokoro et al.
patent: 4809509 (1989-03-01), Hohkita
patent: 5146752 (1992-09-01), Bruestle
patent: 5839281 (1998-11-01), Sumser et al.
patent: 39 02 049 A1 (1990-07-01), None
patent: 42 32 400 (1993-08-01), None
patent: 198 53 360 A1 (2000-05-01), None
Patent Abstracts of Japan—Publication No. 01104925, Publication Date Apr. 21, 1989.
Schmidt Erwin
Sumser Siegfried
Crowell & Moring , L.L.P.
Daimler-Chrysler AG
Denion Thomas
Trieu Thai-Ba
LandOfFree
Turbocharger system for internal combustion engines does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Turbocharger system for internal combustion engines, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Turbocharger system for internal combustion engines will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2457718