Internal combustion engine electric discharge structure

Abstract

An internal combustion engine electric discharge structure is provided which comprises a first electrode and a dielectric material. The first electrode includes a first voltage receiving end and a second engine attachment end with a long thin conductive material that discharges non-equilibrium plasma. The dielectric material covers the first electrode.

1 . An internal combustion engine electric discharge structure comprising:
 a first electrode including a first voltage receiving end and a second engine attachment end with a long thin conductive material that discharges non-equilibrium plasma by a barrier discharge; and   a dielectric material covering the first electrode.   
   
   
       2 . The internal combustion engine electric discharge structure of  claim 1 , further comprising
 a second electrode facing the first electrode on a periphery of the dielectric material.   
   
   
       3 . The internal combustion engine electric discharge structure of  claim 2 , wherein
 the second electrode includes a tubular electrode surrounding at least a portion of the first electrode.   
   
   
       4 . The internal combustion engine electric discharge structure of  claim 3 , further comprising
 a cylinder head having the second electrode attached thereto, with the first electrode including a linear central electrode.   
   
   
       5 . The internal combustion engine electric discharge structure of  claim 2 , wherein
 the first electrode includes a linear central electrode; and   the second electrode is disposed as at least part of one of a wall surface of a combustion chamber and a top surface of a piston.   
   
   
       6 . The internal combustion engine electric discharge structure of  claim 2 , further comprising
 a fuel injection valve for supplying fuel into a combustion chamber of an internal combustion engine; and   a voltage application device operatively coupled to the first voltage receiving end of the first electrode for applying a voltage between the first electrode and the second electrode, such that the non-equilibrium plasma generates radicals within the combustion chamber before an air-fuel mixture in the combustion chamber undergoes autoignition.   
   
   
       7 . The internal combustion engine electric discharge structure of  claim 6 , further comprising
 a control unit operatively coupled to the voltage application device to vary a discharge start timing of the non-equilibrium plasma discharge in accordance with a mechanical load of the internal combustion engine.   
   
   
       8 . The internal combustion engine electric discharge structure of  claim 7 , wherein
 the control unit sets the discharge start timing of the non-equilibrium plasma discharge to occur during an intake stroke when the mechanical load of the internal combustion engine is comparatively low.   
   
   
       9 . The internal combustion engine electric discharge structure of  claim 8 , wherein
 the control unit sets the discharge start timing of the non-equilibrium plasma discharge to be increasingly advanced as the mechanical load of the internal combustion engine becomes lower.   
   
   
       10 . The internal combustion engine electric discharge structure of  claim 7 , wherein
 the control unit sets the discharge start timing of the non-equilibrium plasma discharge to occur during a compression stroke when the mechanical load of the internal combustion engine is comparatively high.   
   
   
       11 . The internal combustion engine electric discharge structure of  claim 10 , wherein
 the control unit sets the discharge start timing of the non-equilibrium plasma discharge to be increasingly delayed as the mechanical load of the internal combustion engine increases.   
   
   
       12 . The internal combustion engine electric discharge structure of  claim 6 , further comprising
 a control unit operatively coupled to the voltage application device to set a discharge start timing of the non-equilibrium plasma discharge to occur after an intake valve has opened.   
   
   
       13 . The internal combustion engine electric discharge structure of  claim 6 , further comprising
 a control unit operatively coupled to the voltage application device to set a discharge ending timing of the non-equilibrium plasma discharge to occur before an intake valve has closed.   
   
   
       14 . The internal combustion engine electric discharge structure of  claim 6 , further comprising
 a control unit operatively coupled to the voltage application device to set a discharge energy of the non-equilibrium plasma discharge such that the discharge energy increases as the mechanical load of the internal combustion engine becomes lower when the mechanical load of the internal combustion engine is in a low load range.   
   
   
       15 . The internal combustion engine electric discharge structure of  claim 14 , wherein
 the control unit increases the discharge energy of non-equilibrium plasma discharge by at least one method selected from
 increasing a voltage value of an AC voltage applied between the first and second electrodes, 
 increasing a frequency of the AC voltage applied between the first and second electrodes, and 
 increasing an application duration of the AC voltage applied between the first and second electrodes. 
   
   
   
       16 . The internal combustion engine electric discharge structure of  claim 6 , further comprising
 a variable compression ratio mechanism arranged to change a mechanical compression ratio of the internal combustion engine; and   a control unit operatively coupled to the variable compression ratio mechanism to reduce the mechanical compression ratio so that an air-fuel mixture does not undergo compression ignition when a mechanical load of the internal combustion engine is in a high load range, and volumetric ignition is performed.   
   
   
       17 . The internal combustion engine electric discharge structure of  claim 6 , further comprising
 a fuel injection control unit operatively coupled to the fuel injection valve to control injection of fuel directly into a cylinder of the internal combustion engine such that a stratified air-fuel mixture is formed in the cylinder when a mechanical load of the internal combustion engine is in a low load range.   
   
   
       18 . An internal combustion engine control method for controlling an operating state of an internal combustion engine, comprising:
 determining a mechanical load of the internal combustion engine;   injecting fuel into a combustion chamber of the internal combustion engine;   applying a voltage to an electric discharge device having a first electrode and a second electrode to produce a non-equilibrium plasma discharge generating radicals within the combustion chamber before an air-fuel mixture of the fuel undergoes autoignition; and   setting a discharge start timing of the non-equilibrium plasma discharge such that the discharge start timing varies in accordance with the mechanical load.