Patent Application
20080087482
As shown in
Centrifugal compressor 26 is powered by variable speed motor 22. Motor 22 is operated by controller 78 and powered by traction battery 74. Traction battery 74 is preferably a high voltage, high current traction battery having operating voltage in the range of 12 to 1000 volts, depending upon the weight of vehicle 8 and the desired engine performance.
Air box 38 includes a naturally aspirated airflow control valve, 42, and a compressed air control valve, 46, with purpose of the control valves to allow air to flow into engine 10 through either compressed air inlet 30 or naturally aspirated air inlet 34. Optionally, intercooler 32 may be interposed between the outlet of compressor 26 and control valve 46.
Engine 10 is connected with a generator, 50, through a planetary gearset, 54. Ring gear 54a of planetary gearset 54 is connected by a gear train, 62, to axle 60, upon which road wheels 66 are mounted. A brake, 58, is positioned between planetary gearset 54 and generator 50, and allows either the generator or gear train 62 to be driven selectively by engine 10. Brake 58 is optional equipment which may be specified according to the needs of any particular vehicle to which the present invention is being applied.
The output of generator 50 is directed to traction battery 74, which is operably connected with traction motor 70, which too, is operated by controller 78. Thus it may be seen that engine 10 may either drive vehicle 8 alone, or traction motor 70 may be used alone to drive vehicle, or a combination of engine 10 and traction motor 70 may be used to power the vehicle.
Controller 78 operates charge air booster 18 as a function of several vehicle operating parameters. In general, it is desired to obtain higher output from engine 10 in response to driver commands such as the time rate of change of position of accelerator pedal 86. Of course, the output of charge air booster 18 is dependent upon the supplied voltage and current available from traction battery 74, as well. Moreover, engine load and speed are important parameters in the calculation of the desired boost from charge air booster 18. A number of operating parameter sensors, 82, are provided. These sensors include a position sensor for accelerator pedal 86, as well as sensors for the state of charge of traction battery 74, various operating temperatures, vehicle speed, engine speed, and yet other parameters known to those skilled in the art and suggested by this disclosure.
Controller 78 operates variable speed motor 22 so as to achieve a desired boost in response to the values of chosen operating parameters. For example, if the time rate of change of the position of accelerator pedal 86 is used as a parameter, a quick depression of the accelerator pedal may be read as an indication that the vehicle's driver has desired maximum or near-maximum acceleration performance, and charge air booster 18 will be energized and operated at a substantial rotational speed. If, however, the time rate of change of the position of accelerator pedal 86 is low, it is a sign that the driver is not attempting to achieve high rates of vehicle acceleration and charge air booster 18 may be operated at a concomitantly lower rotation rate.
As noted above, the battery of sensors 82 tracks various vehicle parameters such as vehicle speed, temperatures such as ambient temperature and engine operating temperature, ambient pressure, battery temperature, battery state of charge, transmission gear position, and other operating parameters known to those skilled in the art and suggested by this disclosure. Such parameters are useful for determining appropriate regimes for powering charge air booster 18. For example, if traction battery 74 is discharged, or if the temperature of engine 10 is too great, charge air booster 18 will not be operated. Manual control 90 is yet another device monitored by sensors 82. Control 90 may be embodied as a driver-selectable switch mounted in the location of other driver-accessible controls. Control 90 could be activated by the motorist so as to power up charge air booster 18 whenever engine 10 is delivering power at speeds above idle.
While particular embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art. Accordingly, it is intended that the invention be limited only in terms of the appended claims.
