Motor vehicles – Power – Having specific motor-to-body-frame relationship
Reexamination Certificate
1998-10-15
2001-08-14
Mai, Lanna (Department: 3619)
Motor vehicles
Power
Having specific motor-to-body-frame relationship
C180S300000
Reexamination Certificate
active
06273208
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates, in general, to vehicles and, specifically, to variable displacement vehicle engines and more specifically, to vehicle drive trains.
2. Description of the Art
Vehicle engines are typically provided with an even number of combustion cylinders, i.e., 4, 6, 8, etc., even though certain engine designs with an odd number of cylinders, such as 5 cylinders, are also known. The amount of fuel/air injected into each cylinder is dependent upon the position of the throttle or accelerator pedal and determines the resulting power applied to the vehicle wheels and the speed of the vehicle. A preset fuel/air mixture is provided under idle conditions when the driver has disengaged his or her foot from the accelerator pedal.
It is known that fuel economy can be significantly improved by stopping the operation of some of the vehicle cylinders under light or partial load driving conditions. In such so-called “variable displacement engines,” the injection of fuel into certain cylinders is stopped, with only the remaining cylinders continuing to operate. Various control schemes have been devised to determine the number of cylinders which are operating or rendered inoperable under various driving load conditions.
While variable displacement engines have proven to significantly increase fuel economy and, consequently to reduce fuel emissions, variable displacement engines create two objectionable problems. First, when a cylinder has ceased operation for a considerable period of time, the temperature of the cylinder wall and other surfaces within the cylinder drop as compared to the continuously operating, fuel burning cylinders. The cooler, inoperative cylinders are required under various power needs to suddenly resume operation when power demand increases. This can cause combustion inefficiency compared with the continuously operated, warmer cylinders and brings about a lower average fuel burning efficiency and an increase in fuel consumption and results in higher pollution exhaust gases from the colder operating cylinders. One approach to address this problem is to constantly shift which specific cylinders are working or nonworking under any load condition according to a preset sequence.
Another problem created by variable displacement engines is a result of inevenly spaced, intermittently operated cylinders anti creates objectionable torsional vibration in the passenger cabin as a result of an unbalanced engine operation when the engine is mounted in a conventional manner intimately connected to the cabin. Such vibrations have inhibited the use of variable displacement engine designs since the vibrations, when transmitted to the passenger compartment, are objectionable.
In a conventional rear wheel drive vehicle, power is transferred from the engine and transmission through a drive shaft to the rear axle and then to the two rear wheels. Since the engine is typically mounted in a conventional fore and aft manner on the frame via engine mounts or on an engine cradle or sub-frame intimately connected with the passenger cabin frame rails, any torsional engine vibrations are transferred from the engine to the passenger cabin or through the transmission and rear axle to the vehicle body via the rear wheels which are connected to the vehicle body by springs and shock absorbers. In addition, forces or shocks are transferred via the rear wheels to the passenger cabin as a result of uneven or rough transmission shifts as well as by shocks introduced on the rear wheel by rough pavement, potholes, etc. The end result of all of these forces which are transmitted to the passenger cabin is an uncomfortable ride for the vehicle passengers.
Torque tube type drive trains have been previously used on rear wheel drive vehicles. For example, a torque tube rigid to the rear axle was connected by a universal ball joint to the rear end of the transmission. The engine in this drive train was mounted to the vehicle by a pair of side positioned rubber mounts in an attempt to cushion engine torsional vibrations from the frame rails connected to the passenger cabin.
Thus, it would be desirable to provide a variable displacement engine which overcomes the problems associated with previously devised variable displacement engines. It would also be desirable to provide a variable displacement engine which maintains the temperature of inoperative cylinders at a minimum temperature suitable for efficient combustion and low pollution emissions when the inoperative cylinders are abruptly brought back into an operative state. It would also be desirable to provide a variable displacement engine with a unique drive train which isolates the torsional engine vibrations and other forces generated by the rear wheels of the vehicle from the passenger cabin. It would also be desirable to provide such a unique drive train which can be easily adapted to current vehicle rear wheel drive trains.
SUMMARY OF THE INVENTION
There is disclosed herein a unique variable displacement engine fuel injector firing means in which fuel injector signals are connected to a selected number of fuel injectors under the control of a throttle controlled switch driven by an engine controller which selects the number of cylinders to be operative under any driving load condition. The unique injector firing signal controlling means sequences between states or positions after each complete injector firing cycle to connect the injector firing signals to all of the other cylinders of the engine in a sequential, rolling manner so as to maintain the temperature of each cylinder above a minimum temperature associated with efficient fuel combustion.
According to the present invention, the variable displacement engine includes a plurality of cylinders, each provided with a fuel injector for injecting fuel into each cylinder oil a timed basis controlled by injector firing signals from an engine controller. The engine controller, in response to varying engine loads, selects any number of the maximum number of cylinders for operation at any given time.
Means connects each fuel injection firing signal from the engine controller to a fuel injector. Means cycle the fuel injector connecting means to all of the cylinders in the engine in a sequential manner in the selected number of operative fuel injectors at a time.
Means are also provided for advancing the fuel injector connecting means one position to connect the selected number of fuel injector firing signals to different fuel injectors upon each sequential generation of the fuel injector signals for the selected number of cylinders.
There is also disclosed herein a unique solid torque tube system for a rear wheel drive vehicle drive train which rigidly interconnects tile engine, the transmission and the rear axle such that the natural frequency of oscillation of the rigidly interconnected engine, the transmission and the interconnecting means is higher than any vibrational frequency that can occur during operation of the engine and vehicle.
In a preferred embodiment, the interconnecting means comprises the engine rigidly fixed to the transmission and a rigid torque tube rigidly connected at one end to the transmission and rigidly fixed at an opposed second end to the rear axle. Preferably, the interconnecting means, the engine and the transmission are substantially co-axial with the longitudinal axis of the vehicle.
Means are provided for pivotally connecting the engine to the vehicle chassis for pivotal movement of the rear axle about an axis horizontally transverse to a longitudinal axis of the interconnecting means with respect to the vehicle chassis. The pivotally connecting means preferably comprises a universal pivotal connection mounted between the vehicle chassis and one end of the engine. The pivotally connecting means also includes means for allowing the interconnecting means to pivot about two mutually exclusive axes with respect to the vehicle chassis.
In one embodiment, the pivotally connecting means includes a pivot bar connected t
Mai Lanna
Restifo Jeffrey J.
Young & Basile PC
LandOfFree
Variable displacement vehicle engine and solid torque tube... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Variable displacement vehicle engine and solid torque tube..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Variable displacement vehicle engine and solid torque tube... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2481198