Variable Valve Operating Apparatus

Abstract

The present invention relates to a variable valve operating apparatus having a switching mechanism for switching between a dual valve variable control mode and a single valve variable control mode, and enhances the durability of the switching mechanism. In an idle state prevailing before a vehicle starts moving, the operating state of an internal combustion engine is in a single valve small lift region (point A). In this instance, the single valve variable control mode prevails. After the vehicle starts moving, the operating state changes from point A through point B to point C and switches to a dual valve great lift region. Subsequently, when an accelerator pedal is released with a clutch disengaged for upshifting, the operating state reverts to point A in the single valve small lift region. In the above situation, as the operating state remains in the dual valve great lift region for a short period of time, a switch to the dual valve variable control mode does not constitute a considerable advantage. Therefore, the switch to the dual valve variable control mode is prohibited when the operating state changes from point B to point C.

1 - 7 . (canceled) 
   
   
       8 . A variable valve operating apparatus comprising:
 a valve mechanism having a switching mechanism for switching between a dual valve variable control mode in which the valve opening amounts of a first valve and a second valve, which are provided for the same cylinder and of the same type, are varied continuously or in multiple steps and a single valve variable control mode in which the valve opening amount of the first valve is varied continuously or in multiple steps with the valve opening amount of the second valve fixed;   storage means for storing rules for dividing an operating region of an internal combustion engine into a dual valve variable control region, for which the dual valve variable control mode should be selected, and a single valve variable control region, for which the single valve variable control mode should be selected;   normal control means for causing the switching mechanism to perform a switching operation in accordance with the rules; and   disable means which, when the operating state of the internal combustion engine is changed from the dual valve variable control region to the single valve variable control region or vice versa within a predetermined period of time after a gear shift by a transmission positioned between the internal combustion engine and vehicle driving wheels, avoids the switching operation by disabling the switching operation in anticipation that the operating state will revert to the previous region within a short period of time.   
   
   
       9 . A variable valve operating apparatus comprising:
 a valve mechanism having a switching mechanism for switching between a dual valve variable control mode in which the valve opening amounts of a first valve and a second valve, which are provided for the same cylinder and of the same type, are varied continuously or in multiple steps and a single valve variable control mode in which the valve opening amount of the first valve is varied continuously or in multiple steps with the valve opening amount of the second valve fixed;   storage means for storing rules for dividing an operating region of an internal combustion engine into a dual valve variable control region, for which the dual valve variable control mode should be selected, and a single valve variable control region, for which the single valve variable control mode should be selected;   normal control means for causing the switching mechanism to perform a switching operation in accordance with the rules;   condition judgment means for judging, when the operating state of the internal combustion engine switches from the dual valve variable control region to the single valve variable control region or vice versa, whether a predefined condition is established for anticipating that the operating state will revert to the previous region within a short period of time;   disable means for disabling the switching operation when the predefined condition is established; and   enable means which, if the operating state of the internal combustion engine does not revert to a previous region within a predetermined period of time after a switch from the dual valve variable control region to the single valve variable control region or vice versa, enables the switching operation no matter whether the predefined condition is established.   
   
   
       10 . A variable valve operating apparatus comprising:
 a valve mechanism having a switching mechanism for switching between a dual valve variable control mode in which the valve opening amounts of a first valve and a second valve, which are provided for the same cylinder and of the same type, are varied continuously or in multiple steps and a single valve variable control mode in which the valve opening amount of the first valve is varied continuously or in multiple steps with the valve opening amount of the second valve fixed;   storage means for storing rules for dividing an operating region of an internal combustion engine into a dual valve variable control region, for which the dual valve variable control mode should be selected, and a single valve variable control region, for which the single valve variable control mode should be selected;   normal control means for causing the switching mechanism to perform a switching operation in accordance with the rules;   condition judgment means for judging, when the operating state of the internal combustion engine switches from the dual valve variable control region to the single valve variable control region or vice versa, whether a predefined condition is established for anticipating that the operating state will revert to the previous region within a short period of time;   disable means for disabling the switching operation when the predefined condition is established;   measurement means for measuring the number of times the switching operation was disabled or the cumulative time during which the switching operation was disabled; and   permission means which, when a predetermined value is exceeded by the number of times the switching operation was disabled or the cumulative time during which the switching operation was disabled, permits the switching mechanism to perform a switching operation no matter whether the predefined condition is established.   
   
   
       11 . A variable valve operating apparatus comprising:
 a valve mechanism having a switching mechanism for switching between a dual valve variable control mode in which the valve opening amounts of a first valve and a second valve, which are provided for the same cylinder and of the same type, are varied continuously or in multiple steps and a single valve variable control mode in which the valve opening amount of the first valve is varied continuously or in multiple steps with the valve opening amount of the second valve fixed;   storage means for storing rules for dividing an operating region of an internal combustion engine into a dual valve variable control region, for which the dual valve variable control mode should be selected, and a single valve variable control region, for which the single valve variable control mode should be selected;   normal control means for causing the switching mechanism to perform a switching operation in accordance with the rules;   condition judgment means for judging, when the operating state of the internal combustion engine switches from the dual valve variable control region to the single valve variable control region or vice versa, whether a predefined condition is established for anticipating that the operating state will revert to the previous region within a short period of time;   disable means for disabling the switching operation when the predefined condition is established; and   valve opening amount limitation means for limiting a target valve opening amount when the switching operation is disabled by the disable means.   
   
   
       12 . A variable valve operating apparatus comprising:
 a valve mechanism having a switching mechanism for switching between a dual valve variable control mode in which the valve opening amounts of a first valve and a second valve, which are provided for the same cylinder and of the same type, are varied continuously or in multiple steps and a single valve variable control mode in which the valve opening amount of the first valve is varied continuously or in multiple steps with the valve opening amount of the second valve fixed;   a storage device for storing rules for dividing an operating region of an internal combustion engine into a dual valve variable control region, for which the dual valve variable control mode should be selected, and a single valve variable control region, for which the single valve variable control mode should be selected;   a normal control device for causing the switching mechanism to perform a switching operation in accordance with the rules; and   a disable device which, when the operating state of the internal combustion engine is changed from the dual valve variable control region to the single valve variable control region or vice versa within a predetermined period of time after a gear shift by a transmission positioned between the internal combustion engine and vehicle driving wheels, avoids the switching operation by disabling the switching operation in anticipation that the operating state will revert to the previous region within a short period of time.   
   
   
       13 . A variable valve operating apparatus comprising:
 a valve mechanism having a switching mechanism for switching between a dual valve variable control mode in which the valve opening amounts of a first valve and a second valve, which are provided for the same cylinder and of the same type, are varied continuously or in multiple steps and a single valve variable control mode in which the valve opening amount of the first valve is varied continuously or in multiple steps with the valve opening amount of the second valve fixed;   a storage device for storing rules for dividing an operating region of an internal combustion engine into a dual valve variable control region, for which the dual valve variable control mode should be selected, and a single valve variable control region, for which the single valve variable control mode should be selected;   a normal control device for causing the switching mechanism to perform a switching operation in accordance with the rules;   a condition judgment device for judging, when the operating state of the internal combustion engine switches from the dual valve variable control region to the single valve variable control region or vice versa, whether a predefined condition is established for anticipating that the operating state will revert to the previous region within a short period of time;   a disable device for disabling the switching operation when the predefined condition is established; and   an enable device which, if the operating state of the internal combustion engine does not revert to a previous region within a predetermined period of time after a switch from the dual valve variable control region to the single valve variable control region or vice versa, enables the switching operation no matter whether the predefined condition is established.   
   
   
       14 . A variable valve operating apparatus comprising:
 a valve mechanism having a switching mechanism for switching between a dual valve variable control mode in which the valve opening amounts of a first valve and a second valve, which are provided for the same cylinder and of the same type, are varied continuously or in multiple steps and a single valve variable control mode in which the valve opening amount of the first valve is varied continuously or in multiple steps with the valve opening amount of the second valve fixed;   a storage device for storing rules for dividing an operating region of an internal combustion engine into a dual valve variable control region, for which the dual valve variable control mode should be selected, and a single valve variable control region, for which the single valve variable control mode should be selected;   a normal control device for causing the switching mechanism to perform a switching operation in accordance with the rules;   a condition judgment device for judging, when the operating state of the internal combustion engine switches from the dual valve variable control region to the single valve variable control region or vice versa, whether a predefined condition is established for anticipating that the operating state will revert to the previous region within a short period of time;   a disable device for disabling the switching operation when the predefined condition is established;   a measurement device for measuring the number of times the switching operation was disabled or the cumulative time during which the switching operation was disabled; and   a permission device which, when a predetermined value is exceeded by the number of times the switching operation was disabled or the cumulative time during which the switching operation was disabled, permits the switching mechanism to perform a switching operation no matter whether the predefined condition is established.   
   
   
       15 . A variable valve operating apparatus comprising:
 a valve mechanism having a switching mechanism for switching between a dual valve variable control mode in which the valve opening amounts of a first valve and a second valve, which are provided for the same cylinder and of the same type, are varied continuously or in multiple steps and a single valve variable control mode in which the valve opening amount of the first valve is varied continuously or in multiple steps with the valve opening amount of the second valve fixed;   a storage device for storing rules for dividing an operating region of an internal combustion engine into a dual valve variable control region, for which the dual valve variable control mode should be selected, and a single valve variable control region, for which the single valve variable control mode should be selected;   a normal control device for causing the switching mechanism to perform a switching operation in accordance with the rules;   a condition judgment device for judging, when the operating state of the internal combustion engine switches from the dual valve variable control region to the single valve variable control region or vice versa, whether a predefined condition is established for anticipating that the operating state will revert to the previous region within a short period of time;   a disable device for disabling the switching operation when the predefined condition is established; and   a valve opening amount limitation device for limiting a target valve opening amount when the switching operation is disabled by the disable device.