Intake system for motorcycle engines having V-shaped cylinder arrangement

Abstract

A motorcycle engine having a V-shaped cylinder arrangement in which a space is defined between the fore and aft cylinders. Carburetors for the fore and aft cylinder are disposed in the space between the cylinders and an air filter is located behind the engine. The motorcycle has a frame which is formed with an inside cavity connected with the air filter and the carburetors so that the inside cavity constitutes a part of the intake passage.

We claim: 
     
       1. A motorcycle comprising a frame, an engine mounted on said frame and including at least one fore cylinder and at least one aft cylinder which are arranged in a V-shaped configuration with a laterally-extending space therebetween, each cylinder having intake port means formed at a side facing into said space, carburetor means disposed in said space and connected with said intake port means in the cylinders, said frame having a closed cavity at least at a portion which is located above the engine, said frame being formed with inlet and outlet port means respectively leading into and out of the cavity, said outlet port means being connected with said carburetor means so that intake air is passed through the cavity in the frame to the carburetor means, and air filter means for passing therethrough the intake air before it is introduced into the closed cavity, said air filter means being disposed behind the engine and mounted on the frame and said inlet port means of the frame is connected with said air filter means so that the intake air is passed from the air filter means through the cavity in the frame to the carburetor means, said air filter means being of a box type configuration having a side cover and a back wall which are connected together to constitute a closed box, said back wall being provided with air inlet and outlet ports and supporting an air filter element disposed between the inlet and outlet ports so that air is passed from said inlet port through the air filter element to the outlet port. 
     
     
       2. A motorcycle in accordance with claim 1 in which said inlet port of the air filter means is associated with an upwardly directed inlet pipe so as to avoid induction of warm air which has been heated by the engine. 
     
     
       3. A motorcycle in accordance with claim 1 in which separate carburetors are provided respectively for the fore and aft cylinders and the carburetors are arranged in a side-by-side relationship. 
     
     
       4. A motorcycle in accordance with claim 3 in which the fore and aft cylinders are transversely offset with each other. 
     
     
       5. A motorcycle according to claim 1 in which said closed cavity is spaced from said cylinders to avoid heating of air in said cavity by said cylinders. 
     
     
       6. A motorcycle comprising; a frame, an engine mounted on said frame and including at least one fore cylinder and at least one aft cylinder which are arranged in a V-shaped configuration with a laterally-extending space therebetween, each cylinder having intake port means formed at a side facing into space, a pair of independent carburetor means, one respective to a fore and one to an aft cylinder, disposed in said space and independently connected with a respective one of said intake port means of a respective one of said cylinders, said frame having a closed cavity at least at a portion which is located above the engine, said frame being formed with inlet port means leading into said cavity, and a pair of outlet port means, each said outlet port means being connected with a respective one of said carburetor means so that intake air is passed through the cavity in the frame to said outlet means, and independently to each of said carburetor means, and air filter means for passing therethrough the intake air before it is introduced into the closed cavity, said aft cylinder having an intake passage extending forwardly through said carburetor means and connected with said cavity at a front portion thereof, said fore cylinder having an intake passage extending rearwardly through said carburetor means and connected with said cavity at a rear portion thereof. 
     
     
       7. A motorcycle in accordance with claim 6 in which said air filter means is disposed behind the engine and mounted on the frame, and said inlet port means of the frame is connected with said air filter means so that the intake air is passed from the air filter means through the cavity to the carburetor means, said air filter being of a box type configuration having a side cover and a back wall which are connected together to constitute a closed box, said back wall being provided with air inlet and outlet ports and supporting an air filter element disposed between the inlet and outlet ports so that air is passed from said inlet port through the air filter element to the outlet port. 
     
     
       8. A motorcycle in accordance with claim 7 in which said inlet port of the air filter means is associated with an upwardly directed inlet pipe so as to avoid induction of warm air which has been heated by the engine. .Iadd. 
     
     
       9.  A motorcycle comprising a frame, an engine mounted on said frame with its crankshaft extending transversely to said frame and including at least one fore cylinder and at least one aft cylinder which are arranged in a V-shaped configuration with a laterally-extending space therebetween, each cylinder having intake port means formed at a side facing into said space, charge forming means disposed contiguous to said space and connected with said intake port means of said cylinders, a closed cavity at least at a portion which is located above the engine and in juxtaposition to said space, said cavity being formed with inlet and outlet port means respectively leading into and out of the cavity, said outlet port means being connected with said charge forming means so that intake air is passed through the cavity to said charge forming means, and air filter means for passing therethrough intake air before it is introduced into the closed cavity through said inlet port, said air filter means comprising an air filter chamber having an intake and an outlet in communication with said cavity inlet port and an air filter element disposed between said intake and said outlet for filtering air before delivery to said cavity. .Iaddend. .Iadd.10. A motorcycle as set forth in claim 9 further including a fuel tank carried by the frame and extending above the engine, said cavity being juxtaposed to said fuel tank. .Iaddend. .Iadd.11. A motorcycle as set forth in claim 10 wherein the fuel tank is saddle shaped and the cavity extends at least in part into the area defined by the saddle. .Iaddend. .Iadd.12. A motorcycle as set forth in claim 11 wherein the air filter element is removable without removing any component of the induction system other than the air filter element and a portion of the 
     
     
        housing surrounding it. .Iaddend. .Iadd.13.  A motorcycle as set forth in claim 10 wherein the air filter intake is associated with an upwardly directly intake pipe so as to avoid induction of warm air which has been heated by said engine. .Iaddend. .Iadd.14. A motorcycle as set forth in claim 10 wherein the air filter chamber is disposed at a side of the closed cavity. .Iaddend. .Iadd.15. A motorcycle comprising: a frame, an engine mounted on said frame with its crankshaft extending transversely to said frame and including at least one fore cylinder and at least one aft cylinder which are arranged in a V-shaped configuration with a laterally-extending space therebetween, each cylinder having intake port means formed at a side facing into said space, a pair of charge forming means disposed contiguous to said space and each being associated with a respective one of said intake port means of a respective one of said cylinders, a closed cavity at least at a portion which is located above the engine and contiguous to said space, inlet port means leading into said cavity, and a pair of outlet port means, each said outlet port means being connected with a respective one of said charge forming means so that intake air is passed through the cavity to said outlet port means, and independently to each of said charge forming means, and air filter means for passing therethrough the intake air before it is introduced into the closed cavity, said aft cylinder having an intake passage extending forwardly through said charge forming means and connected with said cavity at a front portion thereof, said fore cylinder having an intake passage extending rearwardly through said charge forming means and connected with 
     
     
        said cavity at a rear portion thereof. .Iaddend. .Iadd.16.  A motorcycle as set forth in claim 15 further including a fuel tank carried by the frame and extending above the engine, said space being juxtaposed to said fuel tank. .Iaddend. .Iadd.17. A motorcycle as set forth in claim 16 wherein the fuel tank is saddle shaped and the space extends at least in part into the area defined by the saddle. .Iaddend. .Iadd.18. A motorcycle as set forth in claim 17 wherein the air filter element is removable without removing any component of the induction system other than the air filter element and a portion of the housing surrounding it. .Iaddend. .Iadd.19. A motorcycle as set forth in claim 18 wherein the air filter chamber is disposed at a side of the closed cavity. .Iaddend.