Cylinder injection type internal combustion engine and combustion control method at starting thereof

Abstract

A cylinder injection type internal combustion engine includes a fuel injection valve for directly injecting a fuel into a cylinder and a catalyst for cleaning up an exhaust in an exhaust gas and has at least two combustion control patterns for activating rapidly the catalyst. The combustion control patterns are switched over based on a temperature of the catalyst. Furthermore, a stratified combustion is provided at the time of starting by making a configuration of the combustion engine optimum.

What is claimed is:  
     
         1 . A cylinder injection type internal combustion engine, comprising: 
 a fuel injection valve for directly injecting a fuel into a cylinder; and    a catalyst to be activated by HC in an exhaust gas,    wherein a first combustion control pattern of the engine before said catalyst satisfies a temperature condition for enabling activation of the catalyst with the HC in the exhaust gas is different from a second combustion control pattern of the engine after that.    
     
     
         2 . The cylinder injection type internal combustion engine according to    claim 1   , wherein said fuel injection valve has an air inlet provided downward from a fuel measuring section and is configured to inject an air-fuel mixture produced by mixing the air supplied from said inlet and the fuel into the cylinder.  
     
     
         3 . The cylinder injection type internal combustion engine according to    claim 1   , wherein said injection valve has a fuel spray pattern having low rate of deformation for pressure changes in the cylinder.  
     
     
         4 . A method for controlling combustion of a cylinder injection type internal combustion engine at the time of starting, the internal combustion engine comprising a catalyst to be activated by unburned HC, wherein a combustion control pattern in which an amount of the exhausted unburned HC is small and an exhaust gas temperature is high is performed until said catalyst reaches a temperature which enables the unburned HC in the exhaust gas to be cleaned up, and another combustion control pattern in which the exhaust gas containing the unburned HC to be supplied to the catalyst is exhausted is performed after said catalyst reaches the temperature which enables the unburned HC in the exhaust gas to be cleaned up.  
     
     
         5 . A method for controlling combustion of a cylinder injection type internal combustion engine at the time of starting, the cylinder injection type internal combustion engine comprising a fuel injection valve for directly injecting a fuel into a cylinder, and a catalyst to be activated by unburned HC, wherein there are at least two combustion control patterns for activating rapidly said catalyst, and said combustion control patterns are switched over based on a temperature of the catalyst.  
     
     
         6 . A method for controlling combustion of a cylinder injection type internal combustion engine at the time of starting, the engine comprising a fuel injection valve for directly injecting a fuel into a cylinder, and a catalyst to be activated by unburned HC, and having a function of injecting the fuel two times during a combustion stroke and a function of switching over combustion control pattern based on a cooling water temperature of the engine, wherein until a temperature of the catalyst reaches a predetermined value, if the water temperature is lower than a predetermined temperature, the fuel is injected one time during an intake stroke and an ignition timing is retarded near a top dead center, and if the water temperature is higher than the predetermined temperature, the fuel is first injected during a compression stroke and the next injection is preformed during an expansion stroke.  
     
     
         7 . A method for controlling combustion of a cylinder injection type internal combustion engine at the time of starting, the engine comprising a fuel injection valve for directly injecting a fuel into a cylinder and a catalyst to be activated by unburned HC, wherein until a temperature of said catalyst reaches a predetermined value, said injection valve injects the fuel two times during a compression stroke and during the first half of an expansion stroke, and after the temperature of said catalyst reaches the predetermined value, said injection valve injects the fuel two times during the compression stroke and during the latter half of the expansion stroke.  
     
     
         8 . The method for controlling combustion of a cylinder injection type internal combustion engine at the time of starting according to    claim 7   , wherein the injection which occurs during the first half of the expansion stroke is further divided into two injections.  
     
     
         9 . The method for controlling combustion of a cylinder injection type internal combustion engine at the time of starting according to    claim 4   , wherein the fuel is injected during the compression stroke and a stratified combustion operation is conducted at the time of cranking.  
     
     
         10 . The method for controlling combustion of a cylinder injection type internal combustion engine at the time of starting according to    claim 5   , wherein the fuel is injected during the compression stroke and a stratified combustion operation is conducted at the time of cranking.  
     
     
         11 . The method for controlling combustion of a cylinder injection type internal combustion engine at the time of starting according to    claim 6   , wherein the fuel is injected during the compression stroke and a stratified combustion operation is conducted at the time of cranking.  
     
     
         12 . The method for controlling combustion of a cylinder injection type internal combustion engine at the time of starting according to    claim 7   , wherein the fuel is injected during the compression stroke and a stratified combustion operation is conducted at the time of cranking.  
     
     
         13 . The method for controlling combustion of a cylinder injection type internal combustion engine at the time of starting according to    claim 8   , wherein the fuel is injected during the compression stroke and a stratified combustion operation is conducted at the time of cranking.  
     
     
         14 . A method for controlling combustion of a cylinder injection type internal combustion engine at the time of starting, the cylinder injection type internal combustion engine comprising a fuel injection valve for directly injecting a fuel into a cylinder, and a catalyst for cleaning up an exhaust gas in an exhaust pipe, wherein there are two types of combustion control patterns for rapidly activating the catalyst, and after a temperature of the catalyst reaches a predetermined value, combustion is controlled with a combustion control pattern for activating the catalyst, and in the combustion control, the fuel is injected two times during a compression stroke and expansion stroke.  
     
     
         15 . A method for controlling combustion of a cylinder injection type internal combustion engine at the time of starting, the engine comprising a fuel injection valve for directly injecting a fuel into a cylinder, and a catalyst for cleaning up an unburned HC in an exhaust pipe, wherein when a temperature of the catalyst is equal to or lower than a predetermined value, a first fuel injection occurs during a compression stroke and second fuel injection occurs during a early stage in an expansion stroke, and after the temperature of the catalyst reaches the predetermined value, said second fuel injection occurs during a middle stage in the expansion stroke or later.  
     
     
         16 . The method for controlling combustion of a cylinder injection type internal combustion engine at the time of starting according to    claim 7   , wherein the second fuel injection is changed in accordance with a concentration of oxygen in the exhaust gas.  
     
     
         17 . The method for controlling combustion of a cylinder injection type internal combustion engine at the time of starting according to    claim 14   , wherein the second fuel injection is changed in accordance with a concentration of oxygen in the exhaust gas.