BOOSTED ENGINE SYSTEM OF A MOTOR VEHICLE
First Claim
1. A method, comprising:
- responsive to a demanded torque being above a threshold while providing boosted air at a first pressure to an engine via a turbocharger compressor, operating an electric compressor arranged in parallel with the turbocharger compressor and fluidly disconnected from the engine to increase a second pressure in a recirculation circuit around the electric compressor; and
responsive to the second pressure reaching the first pressure, fluidly connecting the electric compressor to the engine.
1 Assignment
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Accused Products
Abstract
Methods and systems are provided for a boosted engine system having an engine arranged to receive boosted air from a variable geometry turbocharger and an electrically powered compressor arranged in parallel with the turbocharger. During temporary high torque demands above a predefined level, the electrically powered compressor may be used to supplement the flow of boosted air from the turbocharger. Additionally, a recirculation circuit around the electrically powered compressor may be provided to build up pressure in the electrically powered compressor before it is connected to the engine so as to minimize fluctuations in engine boost pressure upon start-up of the electrically powered compressor.
7 Citations
20 Claims
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1. A method, comprising:
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responsive to a demanded torque being above a threshold while providing boosted air at a first pressure to an engine via a turbocharger compressor, operating an electric compressor arranged in parallel with the turbocharger compressor and fluidly disconnected from the engine to increase a second pressure in a recirculation circuit around the electric compressor; and responsive to the second pressure reaching the first pressure, fluidly connecting the electric compressor to the engine. - View Dependent Claims (2, 3, 4, 5)
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6. A boosted engine system for a motor vehicle, comprising:
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an internal combustion engine; a small capacity variable geometry turbocharger sized to meet demands for boosted air up to a predefined supply level; and an electrically powered compressor arranged in parallel to the turbocharger, the engine being arranged to receive a primary supply of boosted air during normal engine running below the predefined supply level from the turbocharger and to receive a supplementary supply of boosted air from the electrically powered compressor when it is required to meet a temporary high demand for boosted air above the predefined supply level and a recirculation circuit to build up pressure when the electrically powered compressor is started before the electrically powered compressor is connected to the engine, the recirculation circuit comprising an electrically controlled recirculation valve to control the flow of air through a conduit linking an outlet from the electrically powered compressor to an inlet to the electrically powered compressor, an electrically controlled shut-off valve located between the outlet from the electrically powered compressor and the engine to selectively isolate the outlet from the electrically powered compressor from the engine and a backflow control valve to prevent the backflow of air from the inlet to the electrically powered compressor to atmosphere wherein upon starting of the electrically powered compressor the electrically controlled recirculation valve is kept open and the electrically controlled shut-off valve is kept closed until the pressure in the recirculation circuit has reached a predefined limit whereupon the electrically controlled shut-off valve is opened and the electrically controlled recirculation valve is closed. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method of controlling a boosted engine system of a motor vehicle, the system comprising an engine, a variable geometry turbocharger sized to meet demands for boosted air up to a predefined supply level and an electrically powered compressor arranged in parallel to the turbocharger, the engine being arranged to receive a primary supply of boosted air during normal engine running below the predefined level from the turbocharger and to receive a supplementary supply of boosted air from the electrically powered compressor when it is required to meet a temporary high demand for boosted air above the predefined supply level and a recirculation circuit to build up pressure when the electrically powered compressor is started before the electrically powered compressor is connected to the engine, the boosted engine system further comprising a backflow valve to prevent the backflow of air from an inlet to the electrically powered compressor, an electrically controlled shut-off valve to selectively isolate an outlet of the electrically powered compressor from the engine and a recirculation circuit including a electrically controlled recirculation valve, wherein the method comprises:
checking whether at least one condition for using the electrically powered compressor is present and, if the at least one condition is present, energizing the electrically powered compressor while the electrically controlled shut-off valve is kept closed and the electrically controlled recirculation valve is kept open to build up pressure in the recirculation circuit and, when the pressure in the recirculation circuit has reached a pressure at least equal to the pressure of the primary supply of boosted air, closing the recirculation valve and opening the electrically controlled shut-off valve to supply boosted air to the engine. - View Dependent Claims (18, 19, 20)
Specification