Hybrid car

Abstract

By a lean burn operation, a highly efficient operation region is enlarged, the proportion of engine operation in a low torque condition is increased, and the proportion of motor operation using a battery is decreased. It is possible to provide a hybrid car of an engine-electric motor configuration which can effect a highly efficient operation without increasing the capacity of motor and that of battery.

1 . A hybrid car comprising: 
 an engine;    a power distributing mechanism for distributing the power of said engine;    a torque assisting motor generator disposed on an output shaft of said power distributing mechanism;    a driving shaft connected to said torque assisting motor generator;    a differential motor generator connected to an input shaft of said power distributing mechanism;    a battery connected electrically to both said torque assisting motor generator and said differential motor generator through an inverter;    an engine controlling unit which makes the air/fuel ratio of said engine variable.    
     
     
         2 . A hybrid car according to    claim 1   , wherein said engine is a cylinder-direct fuel injection type engine.  
     
     
         3 . A hybrid car according to    claim 1   , wherein the engine is operated at an air/fuel ratio leaner than a stoichiometric air/fuel ratio, and the air/fuel ratio can be varied linearly.  
     
     
         4 . A hybrid car according to    claim 1   , wherein the engine is operated at an air/fuel ratio leaner than a stoichiometric air/fuel ratio, the air/fuel ratio is varied stepwise, and said torque assisting motor generator is operated as a motor so that there is no difference in driving torque at the time of changing the air/fuel ratio.  
     
     
         5 . A hybrid car according to    claim 1   , wherein the intention of a driver of the vehicle is judged on the basis of at least data including the degree of opening of an accelerator pedal, and an operating point of the engine is controlled to ensure a marginal torque for acceleration.  
     
     
         6 . A hybrid car according to    claim 1   , wherein for deceleration in an operational condition of a large throttle valve opening, said torque assisting motor generator is operated as a generator, thereby effecting the recovery of energy and the application of an engine brake.  
     
     
         7 . A hybrid car according to    claim 1   , wherein a transmission is disposed between a torque distributor and the driving shaft.  
     
     
         8 . A hybrid car according to    claim 1   , wherein when the engine torque is smaller than a predetermined value, said torque assisting motor generator is operated as a motor, allowing the vehicular operation to be performed with the motor, while when a larger engine output is required, the vehicular operation is performed with the engine, and the air/fuel ratio in the engine is varied from a value corresponding to a lean air/fuel ratio to smaller values according to engine torques.  
     
     
         9 . A hybrid car comprising: 
 an engine;    a power distributing mechanism for distributing the power of said engine;    a torque assisting motor generator disposed on an output shaft of said power distributing mechanism;    a driving shaft connected to said torque assisting motor generator;    a differential motor generator connected to an input shaft of said power distributing mechanism;    a battery connected to both said torque assisting motor generator and said differential motor generator through an inverter; and    an engine controlling unit which makes the valve timing of intake and exhaust valves in the engine variable.    
     
     
         10 . A hybrid car comprising: 
 an engine;    a battery connected to a torque assisting motor generator through an inverter;    a lean NOx catalyst for reducing NOx in the exhaust gas from the engine in a lean burn operation; and    a control unit which causes the air/fuel ratio and a torque distribution between the engine and the torque assisting motor generator to be varied.    
     
     
         11 . A hybrid car according to    claim 10   , wherein said lean NOx catalyst causes NOx component to be adsorbed thereon in a lean burn operation and causes it to be reduced in a rich burn operation.  
     
     
         12 . A hybrid car according to    claim 11   , wherein the catalyst when deteriorated by being poisoned with SOx contained in fuel is regenerated by the rich burn operation.  
     
     
         13 . A hybrid car according to    claim 11   , further including: 
 an NOx adsorption estimating means;    an SOx deterioration estimating means; and    a regeneration control determining means;    wherein the air/fuel ratio in regeneration control is set richer than a stoichiometric air/fuel ratio and at the same time the engine torque is decreased and the motor torque is controlled so that there is no difference in a driving shaft torque.    
     
     
         14 . A hybrid car comprising: 
 an engine;    a transmission connected to driving wheels;    a motor generator disposed between said engine and said transmission;    an inverter connected to said motor generator;    a battery A connected to said inverter;    a DC-DC converter for stepping down the voltage of said battery A;    a battery B connected to said DC-DC converter; and    an injector supplied with a driving voltage from said battery A.    
     
     
         15 . A hybrid car according to    claim 14   , wherein said motor generator functions to start the engine, assist a driving torque in acceleration, and recover energy in deceleration.  
     
     
         16 . A hybrid car according to    claim 14   , wherein an injector driving circuit is incorporated in an engine control unit.  
     
     
         17 . A hybrid car according to    claim 14   , wherein said motor generator is cooled with water, said water being used in common to an engine cooling water.  
     
     
         18 . A hybrid car according to    claim 17   , wherein a water-cooling passage for the motor generator is formed upstream of an engine cooling water passage.  
     
     
         19 . A hybrid car comprising: 
 an engine;    a transmission connected to driving wheels;    an alternator A and an alternator B which are different in generated voltage;    a battery A and a battery B which are connected to said alternator A and alternator B, respectively; and    an injector supplied with a driving voltage from said battery A;    wherein the voltage of said battery A is higher than the voltage of said battery B.