Patent Publication Number: US-5297510-A

Title: Volume ignition system

Description:
DESCRIPTION 
     1. Technical Field 
     The present invention relates to spark plugs for internal combustion engines. 
     2. Background Art 
     A typical internal combustion engine is equipped with a spark plug generally similar to standard design including a body member supporting a pair of electrodes to provide a spark gap. This gap is about 1 mm long with a core diameter of spark about 0.1 mm. Transfer of electrical and heat energy to fuel through this very narrow shell around this spark is not efficient. Processes of ignition, combustion and increase of pressure in an engine cylinder are long. 
     A plasma jet system with a spark inside of an insulator with longer gap demands a much higher level of voltage for initiation of the spark. 
     3. Disclosure of Invention 
     This invention is an effort to improve combustion efficiency, emission characteristics and better fuel economy by increasing spark and ignition areas causing transfer of a higher level of electrical and heat energy into the burned fuel. 
     Instead of a very small surface of ignited fuel in a typical spark plug there are created volume ignition processes: 
     discharges basically from a high voltage electrode mainly to a low voltage electrode connected to a spark plug body as sliding discharges and to other low voltage electrodes as a piston and a ring connected to this piston 
     spark plasma injection from a ring connected to a piston into a combustion chamber. 
     For example sliding discharges may be over a cylindrical surface 15 mm long with a diameter of 10 mm. 
     Discharges with a diameter over 10 mm are igniting fuel inside the ring with a resulting injection of plasma outside of it, during the piston&#39;s and the ring&#39;s movement around the high voltage electrode. 
    
    
     Brief Description of Drawing 
     FIG. 1 is a schematic drawing of the invention. 
    
    
     In this figure reference numbers indicate: 
     1. a high voltage electrode; 
     2. a low voltage electrode connected to a spark plug&#39;s body; 
     3. a part of insulation with sliding discharges; 
     4. a metallization of an inner conical surface of a part of insulation with sliding discharges; 
     5. a ring-a low voltage electrode, connected to a piston, moving around a high voltage electrode; 
     6. a piston-a low voltage electrode; and 
     7. a central hollow inside a high voltage electrode. 
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Electrical discharges are developing simultaneously basically from a high voltage electrode 1, during movement of a piston 6 with a connected ring 5, as low voltage electrodes, around this high voltage electrode 1, and to a low voltage electrode 2 connected to the spark plug body. 
     Sliding discharges are created between the high voltage electrode 1 and the low voltage electrode 2 along a metallization 4 of an inner conical surface of an insulator 3, which material has a higher dielectric constant, over a long cylindrical outer surface of the insulator 3, with a large diameter. Those sliding discharges are symmetrical and cause volume ignition of fuel in an upper part of an engine&#39;s cylinder. 
     At the beginning fuel inside the ring 5 and between a central hollow 7 of the high voltage electrode 1 and the piston 6 is ignited by discharges from the high voltage electrode 1, during the piston 6 and ring&#39;s movement around this high voltage electrode 1. After it flames spread outside, from inside of the central hollow 7 of the high voltage electrode 1 and the ring 5, causing elongation of discharge plasma. This is another volume ignition process of fuel in a bottom part of the engine cylinder. 
     The first process of increasing pressure is between the high voltage electrode 1 and the ring 5 and the piston 6 where burning process of fuel is the shortest. The next pressure increase occurs throughout the engine cylinder.