High-power engine and vehicle

Abstract

A length of a partition of an intake port is set such that the ratio between the length of the partition and the distance between the centers of adjacent intake valves is not less than 0.45 nor more than 0.72. An injector is attached on the upper side of a throttle body. The angle Φ at which the injector is attached is set to be not less than 42 degrees nor more than 55 degrees. The injection starting timing of the injector is set within the periods in which the intake valves are closed.

1 . A high-power engine comprising:
 a cylinder;   a cylinder head provided to form a combustion chamber together with said cylinder, and having an intake port that guides air into said combustion chamber;   a plurality of intake valves disposed to open and close at downstream opening ends of said intake port; and   a fuel injection device disposed to inject fuel toward an inner wall of said intake port in a position that is further upstream than said intake valves,   wherein said intake port has a plurality of branch passages separated by a partition to guide air respectively to said plurality of intake valves, and   a ratio of a length of said partition with respect to a distance between centers of adjacent ones of said intake valves is set to be not less than 0.45 nor more than 0.72.   
     
     
         2 . The high-power engine according to  claim 1 , further comprising a throttle valve that opens and closes in a position further upstream than said intake port, wherein said fuel injection device is disposed on a side where a stronger flow of air is produced than on another side when said throttle valve opens. 
     
     
         3 . The high-power engine according to  claim 1 , further comprising an intake pipe having an inner space that communicates with said intake port,
 wherein said intake port and the inner space of said intake pipe form an approximately linear-shaped air intake passage,   said throttle valve is provided such that its upper end opens to a downstream side and its lower end opens to an upstream side in said intake pipe, and   said fuel injection device is provided on an upper side of said intake pipe such that said fuel injection device injects the fuel toward a lower side of the inner wall of said intake port.   
     
     
         4 . The high-power engine according to  claim 1 , wherein an angle between a direction in which said fuel injection device injects the fuel and a center axis of said intake port is set to be not less than 42 degrees nor more than 55 degrees. 
     
     
         5 . The high-power engine according to  claim 1 , wherein the fuel injection by said fuel injection device is started in a period in which said plurality of intake valves are closed. 
     
     
         6 . A vehicle comprising:
 a high-power engine;   a wheel; and   a transmission mechanism that transmits power generated by said high-power engine to said wheel,   said high-power engine comprising:   a cylinder;   a cylinder head provided to form a combustion chamber together with said cylinder, and having an intake port that guides air into said combustion chamber;   a plurality of intake valves disposed to open and close at downstream opening ends of said intake port; and   a fuel injection device disposed to inject fuel toward an inner wall of said intake port in a position that is further upstream than said intake valves,   wherein said intake port has a plurality of branch passages separated by a partition to guide air respectively to said plurality of intake valves, and   a ratio of a length of said partition with respect to a distance between centers of adjacent ones of said intake valves is set to be not less than 0.45 nor more than 0.72.   
     
     
         7 . The vehicle according to  claim 6 , further comprising a throttle valve that opens and closes in a position further upstream than said intake port, wherein said fuel injection device is disposed on a side where a stronger flow of air is produced than on another side when said throttle valve opens. 
     
     
         8 . The vehicle according to  claim 6 , further comprising an intake pipe having an inner space that communicates with said intake port,
 wherein said intake port and the inner space of said intake pipe form an approximately linear-shaped air intake passage,   said throttle valve is provided such that its upper end opens to a downstream side and its lower end opens to an upstream side in said intake pipe, and   said fuel injection device is provided on an upper side of said intake pipe such that said fuel injection device injects the fuel toward a lower side of the inner wall of said intake port.   
     
     
         9 . The vehicle according to  claim 6 , wherein an angle between a direction in which said fuel injection device injects the fuel and a center axis of said intake port is set to be not less than 42 degrees nor more than 55 degrees. 
     
     
         10 . The vehicle according to  claim 6 , wherein the fuel injection by said fuel injection device is started in a period in which said plurality of intake valves are closed.