Engine with direct turbo compounding

• US 6,276,138 B1
• Filed: 09/10/1999
• Issued: 08/21/2001
• Est. Priority Date: 09/10/1999
• Status: Expired due to Fees

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Welch, Peter Damien
• Primary Examiner(s): Denion, Thomas
• Assistant Examiner(s): TRIEU, THAI BA
• Application Number:
  US09/393,876
• Time in Patent Office: 711 Days
• Field of Search: 606/02, 606/051, 605/97, 605/98, 123/198.F, 123/198.DB, 123/90.16, 123/90.41
• US Class Current: 60/602
• CPC Class Codes: F02D 17/02 Cutting-out cutting-out engines in multiple engine arrangements F02D25/04

Abstract

A multi-cylinder Otto cycle internal combustion direct compound engine for motor vehicles with an exhaust-gas turbocharger providing direct turbo compounding upon the engine control module receiving a speed signal indicating that the vehicle is traveling in a predetermined cruise-speed mode. Upon receipt of the signal the module turns-off each fuel injector feeding a second group of the cylinders, while maintaining fuel injection to a first group of cylinders and fully opening the electronic intake-air induction throttle. As a result the unfired second group of cylinder pistons are driven solely by compressed inlet-air pressure during the time the vehicle travels at or above a predetermined light-load cruising-speed, while positive pumping work occurs in all the cylinders. The engine thus conserves fuel during light load cruising speed while maintaining low pollutant emissions.

Claims

1. A multi-cylinder Otto cycle direct compound internal combustion engine for a motor vehicle comprising:

a compressor of an exhaust-gas turbocharger draws-in and compresses outside air, for delivery, via an electronic throttle valve and an intake manifold, to first and second groups of engine cylinders;

the first group of cylinders are connected to a first exhaust manifold for delivery of their exhaust-gas to drive a turbine of the turbocharger, via an electronic by-pass valve;

the by-pass valve being operable, by pressure sensing means of a power-train control module, to direct part or all of the exhaust-gas to drive the turbine, and whereby the exhaust-gas from the first group of pistons is exited, through first catalytic converter means, to the atmosphere;

the second group of cylinders are connected to a second exhaust manifold, whereby during the time the second group of cylinders are fired their exhaust-gas is exited, through second catalytic converter means, to the atmosphere; and

the control module adapted for regulating a fuel injector for each of the engine cylinders, whereby upon speed sensor means of the control module indicating the vehicle speed has reached a predetermined light-load cruise-speed mode, wherein the control module deactivates each second group cylinder fuel injector, resulting in each second group cylinder being powered solely by compressed air boost pressure, via the intake manifold, such that the engine achieves increased fuel efficiency during operation of the vehicle in the cruising-speed mode.

2. The direct compound engine as recited in claim 1 wherein the first and second catalytic converter means comprising first and second catalytic converters with the first catalytic converter positioned juxtaposed a second catalytic converter, wherein during each time interval that the engine is operated in its cruise-speed mode, resulting in only compressed intake air flowing through the second catalytic converter, such that sufficient heat transfer occurs from the first converter to the second converter thereby maintaining the second converter at or above its predetermined operating temperature;

and

upon the vehicle speed falling below the cruise-speed mode, speed sensor means of the control module activates each second group fuel injector, whereby the second catalytic converter is adapted to immediately convert pollutants in the exhaust-gas flow from the second group cylinders to less harmful substances, by virtue of maintaining the second converter at or above its operating temperature during the vehicle'"'"'s light-load cruise-speed mode.

3. The direct compound engine as recited in claim 2 wherein the first and second primary catalytic converters each having an outer metal casing enclosing its associated catalyst materials, and wherein the first converter outer casing of a predetermined size such that it encloses the second converter outer casing, thereby providing maximum heat transfer from the first converter to the second converter during operation of the vehicle in its cruise-speed mode.

4. The direct compound engine as recited in claim 3 wherein the first and second catalytic converters each have a cylindrical outer metal casing, and wherein the first converter outer casing is concentrically disposed about the second converter outer casing, thereby minimizing the space occupied by the first and second converters.

5. The direct compound engine as recited in claim 1 wherein the engine is an in-line four-cylinder engine, and wherein a first pair of adjacent cylinders comprise the first group of cylinders and a second pair of adjacent cylinders comprise the second group of cylinders.

6. The direct compound engine as recited in claim 1 wherein the engine is provided with dual-event camshaft/rocker arm means, such that during the light-load cruise-speed mode the operation of the second group of cylinders is converted from four-cycle air expanders to two-cycle air expanders thereby increasing the fuel efficiency of the engine during the cruise-speed mode.

7. A method for increasing the fuel economy of a vehicle internal combustion direct compound engine operated by a power-train control module, the engine provided with an exhaust-gas turbocharger having turbine and compressor elements located on a common shaft, and wherein first and second groups of engine cylinders are each supplied fuel by an associated fuel injector, the method comprising:

expelling exhaust-gas from the first group of fired cylinders, via a first exhaust manifold, to drive the turbine by means of the engine exhaust gas, via a first exhaust manifold, and directing the exhaust-gas from the first group of cylinders through first catalytic converter means;

sensing a predetermined vehicle light-load cruise-speed by the power-train control module, wherein the fuel injector of each second group cylinder is deactivated;

drawing in fresh intake air by a compressor of the turbocharger for supply, in compressed form, to drive each second group unfired cylinder, whereby each second group cylinder is powered solely by compressed intake-air during operation of the vehicle in a light-load cruise-speed mode;

expelling exhaust-gas by the fired second group of cylinders, via a second exhaust manifold, for flow through a second catalytic converter means, during operation of the vehicle in a speed range below its cruise-speed range, wherein the fuel injector of each second group cylinder is activated;

expelling intake-air by the unfired second group of cylinders, via a second exhaust manifold, for flow through second catalytic converter means, during operation of the vehicle in its predetermined light-load cruise-speed mode; and

applying heat to the second converter means during the cruise speed mode, thereby maintaining the second converter means at or above its predetermined operating temperature, whereby the second converter means is operative to immediately convert pollutants in the exhaust-gas, delivered to the second converter means from the second group of cylinders, into less harmful substances.

8. The method recited in claim 7 wherein the first and second catalytic converter means are in the form of first and second juxtaposed catalytic converters that sufficient heat is transferred from the first converter to the second converter during the cruise-speed mode, thereby maintaining the second converter at or above its predetermined operating temperature.

9. The method recited in claim 8 wherein the first converter surrounds the second catalytic converter in a sealed manner to provide maximum heat transfer from the first converter to the second converter.

10. The method recited in claim 7 wherein converting the second group of unfired cylinders from four-cycle operation to two-cycle operation by installing a dual-event camshaft/rocker arm, thereby increasing engine fuel efficiency during the cruise speed mode.