Intake valve timing in multi-valve, camless engines

Abstract

Two intake valves are independently operated by electromechanical actuators and activated by the engine electronic controller. One tumble-type intake valve and one conventional intake valve are provided in each cylinder. The valve members are individually opened and closed to achieve a desired air flow pattern in the combustion chamber to optimize combustion which increases fuel economy and reduces undesirable emissions. The opening and closing of the valve members depends on the engine speed, engine load, and other factors.

1. A method for generating turbulence of an air-fuel mixture in a combustion chamber of a multi-valve engine, said engine having at least first and second intake valve members each independently activated by an actuator member, with the activation of the actuator member being controlled by an engine controller unit, the method comprising the steps of:
 determining a first operating condition, a second operating condition, and a third operating condition of the engine; 
 separately operating the intake valve members to generate an air-fuel turbulence in the engine combustion chamber corresponding at least In in part to the first, second and third operating conditions, so that under a first operating condition a high swirl, no tumble turbulence is formed, under a second operating condition a swirl and tumble turbulence is formed, and under a third operating condition a tumble, no swirl turbulence is formed; 
 wherein the optimum air-fuel turbulence is created for the operating condition to maximize fuel efficiency and minimize undesirable emissions. 
 
     
     
       2. The method for generating turbulence as set forth in  claim 1  wherein a look-up table is utilized to operate the actuator members and accompanying intake valve members depending on engine load and speed. 
     
     
       3. The method for generating turbulence as set forth in  claim 1  wherein said intake valve members are operated in accordance with a look-up table which has been established for the engine. 
     
     
       4. The method for generating turbulence as set forth in  claim 1  wherein said first intake valve member is a tumble-type intake valve member. 
     
     
       5. The method for generating turbulence as set forth in  claim 1  wherein said second intake valve member is a conventional intake valve member. 
     
     
       6. The method for generating turbulence as set forth in  claim 1  wherein said first intake valve member is a tumble-type intake valve member and said second intake valve member is a conventional intake valve member. 
     
     
       7. The method for generating turbulence as set forth in  claim 6  wherein in light-load conditions of the engine, said first valve member is disabled and only said second valve is operated. 
     
     
       8. The method for generating turbulence as set forth in  claim 6  wherein in light-load conditions of the engines, said first valve member is disabled and a swirl air flow motion is generated in the combustion chamber. 
     
     
       9. The method for generating turbulence as set forth in  claim 6  wherein in a first mid-load condition, an inclined swirl air flow motion is generated in the combustion chamber. 
     
     
       10. The method for generating turbulence as set forth in  claim 9  wherein said inclined swirl air flow is generated by first opening said second valve for a first portion of the intake process and then concurrently opening said first valve for a second portion of the intake process. 
     
     
       11. The method for generating turbulence as set forth in  claim 9  wherein said second valve is disabled. 
     
     
       12. The method for generating turbulence as set forth in  claim 1  wherein in a second mid-load condition of the engine, a tumble air flow motion is generated in the combustion chamber. 
     
     
       13. The method for generating turbulence as set forth in  claim 12  wherein said tumble air flow motion is generated by timing the openings of both of said first and second valve members during the intake process. 
     
     
       14. The method for generating turbulence as set forth in  claim 1  wherein in a full-load condition of the engine, both of said first and second valve members are operated at conventional timings for the engine. 
     
     
       15. A process for optimizing the air-flow motion in the cylinder combustion chambers of a multi-valve engine, each of said cylinders having a first intake valve and a second intake valve, both of said first and second intake valves being individually and independently operated, and the engine having an electronic controller for operating said first and second intake valves, said process comprising the steps of:
 establishing a plurality of operating conditions for the engine based on engine load and speed; 
 preparing a look-up table based on said plurality of operating conditions; 
 operating said first and second intake valves depending on the look-up table relative to a first engine load and speed; and 
 generating an air flow motion in the cylinder combustion chamber corresponding to one of said plurality of operating conditions, so that under a first operating condition of said plurality of operating conditions a high swirl, no tumble turbulence is formed, under a second operating condition of said plurality of operating conditions a swirl and tumble turbulence is formed and, and under a third operating condition of said plurality of operating conditions a tumble, no swirl turbulence is formed. 
 
     
     
       16. A system for generating turbulence of an air-fuel mixture in a combustion chamber of a multi-valve engine, said engine having at least first and second intake valve members, and a controller unit, said system comprising:
 means for determining a first operating condition, a second operating condition, and a third operating condition of the engine; 
 means for separately operating said first and second intake valve members in order to generate a desired air-fuel turbulence in the engine combustion chamber corresponding at least in pan part to said first, second and third operating conditions, so that under a first operating condition a high swirl, no tumble turbulence is formed, under a second operating condition a swirl and tumble turbulence is formed, and under a third operating condition a tumble, no swirl turbulence is formed; 
 wherein an optimum air fuel turbulence is created for said operating condition to maximize fuel efficiency and minimize undesirable emissions. 
 
     
     
       17. The system as set forth in  claim 16  wherein said means for determining an operating condition comprises a look-up table. 
     
     
       18. The system as set forth in  claim 16  wherein said first intake valve member is a tumble-type intake valve member and said second intake valve member is a conventional intake valve member. 
     
     
       19. The system as set forth in  claim 16  wherein a plurality of operating conditions are established for the engine based on engine load and engine speed and said first and second intake valve members are separately operated in accordance with one of said operating conditions in order to generate a corresponding air flow motion in the combustion chamber. 
     
     
       20. The system as set forth in  claim 17  wherein said look-up table contains a plurality of operating conditions for the engine based on engine load and engine speed, and said first and second intake valve members are separately operated in accordance with one of said operating conditions in order to generate a corresponding air flow motion in the combustion chamber. 
     
     
       21. A multi-valve engine for a vehicle, the multi-valve engine comprising:
 at least one cylinder including:
 a combustion chamber; 
 an air intake passageway; 
 a first intake valve positioned at the interface of the combustion chamber and the air intake passageway; 
 a first electromechanical actuator configured to operate the first intake valve; 
 a second intake valve positioned at the interface of the combustion chamber and the air intake passageway; and 
 a second electromechanical actuator configured to operate the second intake valve; 
   a controller configured to independently operate each intake valve via the first and second electromechanical actuators;   the controller being further configured to produce time phasing of the opening and closing of the valve members relative to each other during the intake stroke;   where variable operation of the first and second intake valves produces varying amounts of swirl and/or tumble turbulence.   
     
     
       22. The multi-valve engine of claim 21, where the first intake valve member is a conventional intake valve member. 
     
     
       23. The multi-valve engine of claim 21, where the second intake valve member is a tumble-type intake valve member. 
     
     
       24. The multi-valve engine of claim 21, where the first intake valve member is a conventional intake valve member and the second intake valve member is a tumble-type intake valve member. 
     
     
       25. The multi-valve engine of claim 21, where a high swirl, no tumble turbulence is formed by operating the first valve member without operating the second valve member. 
     
     
       26. The multi-valve engine of claim 21, where a swirl and tumble turbulence is formed by operating the first and second valve members. 
     
     
       27. The multi-valve engine of claim 21, where a high tumble, no swirl turbulence is formed by operating the second valve member without operating the first valve member. 
     
     
       28. The multi-valve engine of claim 21, where an inclined swirl air flow motion is generated by first opening the first valve for a first portion of the intake process and then concurrently opening the second valve for a second portion of the intake process. 
     
     
       29. An electromechanical valve control system for a multi-valve engine for a vehicle, the control system comprising:
 a cylinder including
 a first electromechanically-operated intake valve; and 
 a second electromechanically-operated intake valve; 
   a controller in electronic communication with the first and second intake valves, the controller being configured to receive information related to the operating condition of the vehicle and independently operate the first and second intake valves in response to the operating condition;   where, under a first operating condition, the first intake valve is operated and the second intake valve is not operated, and under a second operating condition, the second intake valve is operated and the first intake valve is not operated; and   where variable operation of the first and second intake valves produces varying amounts of swirl and/or tumble turbulence.   
     
     
       30. The multi-valve engine of claim 29, where the first intake valve member is a conventional intake valve member. 
     
     
       31. The multi-valve engine of claim 29, where the second intake valve member is a tumble-type intake valve member. 
     
     
       32. The multi-valve engine of claim 29, where the first intake valve member is a conventional intake valve member and the second intake valve member is a tumble-type intake valve member. 
     
     
       33. The multi-valve engine of claim 29, where a high swirl, no tumble turbulence is formed by operating the first valve member without operating the second valve member. 
     
     
       34. The multi-valve engine of claim 29, where a swirl and tumble turbulence is formed by operating the first and second valve members. 
     
     
       35. The multi-valve engine of claim 29, where a high tumble, no swirl turbulence is formed by operating the second valve member without operating the first valve member. 
     
     
       36. The multi-valve engine of claim 29, where an inclined swirl air flow motion is generated by first opening said first valve for a first portion of the intake process and then concurrently opening said second valve for a second portion of the intake process. 
     
     
       37. A multi-valve engine for a vehicle, the multi-valve engine comprising:
 at least one cylinder including:
 a combustion chamber; 
 an air intake passageway; 
 a first intake valve positioned at the interface of the combustion chamber and the air intake passageway; 
 a first electromechanical actuator configured to operate the first intake valve; 
 a second intake valve positioned at the interface of the combustion chamber and the air intake passageway; and 
 a second electromechanical actuator configured to operate the second intake valve; 
   a controller configured to independently operate each intake valve via the first and second electromechanical actuators; and   the controller being further configured to produce time phasing of the opening and closing of the valve members relative to each other during an intake stroke.   
     
     
       38. The multi-valve engine of claim 37, where the time phasing produces a delay in the operation of the first intake valve relative to the second under a first predetermined operating condition. 
     
     
       39. The multi-valve engine of claim 37, where the time phasing produces a delay in the operation of the second intake valve relative to the first under a second predetermined operating condition. 
     
     
       40. The multi-valve engine of claim 39, where the controller is further configured to prevent operation of the first intake valve under a third predetermined operating condition. 
     
     
       41. The multi-valve engine of claim 40, where the controller is further configured to prevent operation of the second intake valve under a fourth predetermined operating condition. 
     
     
       42. The multi-valve engine of claim 37, where solo operation of the first valve is configured to produce a first flow pattern. 
     
     
       43. The multi-valve engine of claim 37, where solo operation of the second valve is configured to produce a second flow pattern. 
     
     
       44. The multi-valve engine of claim 37, where simultaneous operation of the first and second valves is configured to produce a third flow pattern. 
     
     
       45. The multi-valve engine of claim 37, where delayed operation of the first valve relative to the second is configured to produce a fourth flow pattern. 
     
     
       46. The multi-valve engine of claim 37, where delayed operation of the second valve relative to the first is configured to produce a fifth flow pattern. 
     
     
       47. An electromechanical valve control system for a multi-valve engine for a vehicle, the control system comprising:
 a cylinder including
 a first electromechanically-operated intake valve; and 
 a second electromechanically-operated intake valve; 
   a controller in electronic communication with the first and second intake valves, the controller being configured to receive information related to the operating condition of the vehicle and independently operate the first and second intake valves in response to the operating condition;   wherein, under a first operating condition, the first intake valve is operated and the second intake valve is not operated; and under a second operating condition, the second intake valve is operated and the first intake valve is not operated.   
     
     
       48. The multi-valve engine of claim 47, where solo operation of the first valve is configured to produce a first flow pattern. 
     
     
       49. The multi-valve engine of claim 47, where solo operation of the second valve is configured to produce a second flow pattern. 
     
     
       50. The multi-valve engine of claim 47, where simultaneous operation of the first and second valves is configured to produce a third flow pattern. 
     
     
       51. The multi-valve engine of claim 47, where delayed operation of the first valve relative to the second is configured to produce a fourth flow pattern. 
     
     
       52. The multi-valve engine of claim 47, where delayed operation of the second valve relative to the first is configured to produce a fifth flow pattern. 
     
     
       53. A method for operating a multi-valve engine under various operating conditions, the multi-valve engine including at least one cylinder having at least a first and a second electrically-controlled intake valve, the method comprising:
 under a first vehicle operating condition, operating the first intake valve but not the second; and   under a second vehicle operating condition, operating the second intake valve but not the first.   
     
     
       54. The method of claim 53 further comprising:
 under a third vehicle operating condition, time phasing the operation of the first and second intake valves relative to each other during an intake stroke.   
     
     
       55. The method of claim 54 where the step of time phasing the operation of the first and second intake valves relative to each other comprises delaying operation of the first or second intake valve in relation to the other during an intake stroke. 
     
     
       56. The method of claim 53 further comprising:
 under a fourth vehicle operating condition, opening the first intake valve to a lesser or greater extent than the second intake valve.   
     
     
       57. A method for operating a multi-valve engine under various operating conditions, the multi-valve engine including at least one cylinder having at least a first and a second electrically-controlled intake valve, the method comprising:
 under a first operating condition, time phasing the operation of the first and second valves relative to each other during an intake stroke.   
     
     
       58. The method of claim 57, where the step of time phasing the operation of the first and second valves relative to each other comprises delaying the timing of operation of the first or second intake valve in relation to the timing of the other. 
     
     
       59. The method of claim 58, where delaying operation of the timing of the first intake valve relative to the timing of the second intake valve produces a first flow pattern. 
     
     
       60. The method of claim 59, where delaying operation of the timing of the second intake valve relative to the timing of the first intake valve produces a second flow pattern.