Methods and apparatus to use engine valves as both intake and exhaust valves

Abstract

Methods and apparatus to selectively use engine valves as both intake and exhaust valves and to selectively operate the engine as a 2 cycle or as a 4 cycle engine. In a disclosed embodiment, the intake valves and the exhaust valves, are manifolded together through a small manifold, with the manifold being connectable to the intake manifold or the exhaust manifold through two-way valves. In preferably a camless engine, the engine valves may be controlled to operate the intake valves as intake valves only or to operate as both intake valves and exhaust valves, and to operate the exhaust valves as exhaust valves only or to operate the exhaust valves as both intake valves and exhaust valves. Exemplary embodiments are disclosed.

1 . A piston engine comprising: 
 at least one intake valve and at least one exhaust valve per piston engine cylinder; and,    a flow control valve system for controllably coupling the at least one intake valve to an intake manifold or to an exhaust manifold, and for controllably coupling the at least one exhaust valve to an exhaust manifold or to an intake manifold;    the at least one intake valve and at least one exhaust valve per piston engine cylinder being actuated by camless actuators.    
   
   
       2 . The piston engine of  claim 1  wherein the flow control system comprises two, two-way valves per cylinder.  
   
   
       3 . The piston engine of  claim 2  wherein for each intake valve, a first two-way valve controllably couples the intake valve to the intake manifold or blocks the coupling of the intake valve to the intake manifold, and for each exhaust valve, a second two-way valve controllably couples the exhaust valve to the exhaust manifold or blocks the coupling of the intake valve to the exhaust manifold, the at least one intake valve and the at least one exhaust valve being manifolded together.  
   
   
       4 . The piston engine of  claim 3  wherein a first two-way valve controllably couples the at least one intake valve to the intake manifold or blocks the coupling of the at least one intake valve to the intake manifold, and a second two-way valve controllably couples the at least one exhaust valve to the exhaust manifold or blocks the coupling of the at least one intake valve to the exhaust manifold, the at least one intake valve and the at least one exhaust valve being manifolded together.  
   
   
       5 . The piston engine of  claim 1  further comprising a control system for controlling the camless actuators and the flow control valve system to operate the engine as a four cycle engine or as a two cycle engine.  
   
   
       6 . The piston engine of  claim 1  further comprising a control system for controlling the camless actuators and the flow control valve system to operate the engine using the intake valves for intake and the exhaust valves for exhaust, and to operate the engine using the intake valves for both intake exhaust and the exhaust valves for both intake and exhaust.  
   
   
       7 . The piston engine of  claim 1  wherein the flow control system couples the intake valves to the intake manifold or blocks the coupling of the intake valves to the intake manifold, and couples the exhaust valves to the exhaust manifold or blocks the coupling of the exhaust valves to the exhaust manifold, the at least one intake valve and the at least one exhaust valve being manifolded together.  
   
   
       8 . The piston engine of  claim 1  wherein the piston engine is a camless engine further comprising: 
 a control system for each cylinder to control the intake and exhaust valves so that;    at times, the piston engine operates as a 4 cycle engine using the at least one intake valve as intake valves and the at least one exhaust valve as exhaust valves; and    at other times, the piston engine operates as a 4 cycle engine using all the intake and exhaust valves as intake valves and all intake and exhaust valves as exhaust valves.    
   
   
       9 . The piston engine of  claim 8  further comprising at still other times, the control system controls the intake and exhaust valves so that the piston engine operates as a 2 cycle engine.  
   
   
       10 . The piston engine of  claim 9  wherein the piston engine sometimes operates as a 2 cycle engine using all the intake and exhaust valves as intake valves and all intake and exhaust valves as exhaust valves.  
   
   
       11 . A method of operating a camless piston engine having at least one intake valve and at least one exhaust valve per cylinder comprising: 
 for each cylinder;    at times, operating the piston engine as a 4 cycle engine using the at least one intake valve as intake valves and the at least one exhaust valve as exhaust valves; and    at other times, operating the piston engine as a 4 cycle engine using all the intake and exhaust valves as intake valves and all intake and exhaust valves as exhaust valves.    
   
   
       12 . The method of  claim 11  further comprising at still other times, operating the piston engine as a 2 cycle engine.  
   
   
       13 . The method of  claim 12  wherein the piston engine is sometimes operated as a 2 cycle engine using all the intake and exhaust valves as intake valves and all intake and exhaust valves as exhaust valves.  
   
   
       14 . In a piston engine, the improvement comprising: 
 at least one intake valve and at least one exhaust valve per piston engine cylinder; and,    a flow control system for each cylinder for controllably coupling the at least one intake valve to an intake manifold or to an exhaust manifold, and for controllably coupling the at least one exhaust valve to an exhaust manifold or to an intake manifold.    
   
   
       15 . The improvement of  claim 14  wherein the flow control system comprises one two-way valve per intake valve and one two-way valve per exhaust valve.  
   
   
       16 . The improvement of  claim 15  wherein for each intake valve, a first two-way valve controllably couples the intake valve to the intake manifold or blocks the coupling of the intake valve to the intake manifold, and for each exhaust valve, a second two-way valve controllably couples the exhaust valve to the exhaust manifold or blocks the coupling of the exhaust valve to the exhaust manifold, the at least one intake valve and the at least one exhaust valve being manifolded together.  
   
   
       17 . The improvement of  claim 15  wherein the piston engine includes multiple intake valves and multiple exhaust valves, the flow control system having an air flow area at least as large as the combined intake and exhaust valve air flow area when coupling the intake and exhaust valves to an intake manifold, and when coupling the intake and the exhaust valves to an exhaust manifold.  
   
   
       18 . The improvement of  claim 14  wherein the flow control system couples the intake valves to the intake manifold or blocks the coupling of the intake valves to the intake manifold, and couples the exhaust valves to the exhaust manifold or blocks the coupling of the exhaust valves to the exhaust manifold, the at least one intake valve and the at least one exhaust valve being manifolded together.