Variable valve device for internal combustion engine

1. A variable valve device for an internal combustion engine, the device comprising:

a camshaft which is rotatably provided in an internal combustion engine while having a cam;

a rocker shaft which is arranged next to the camshaft;

a valve is driven by the cam;

a cam follower rocker which is rotatably provided in the rocker shaft, and is rocked by following the cam;

a valve drive rocker which is rotatably provided in the rocker shaft next to the cam follower rocker, and drives the valve, either a body of the cam follower rocker or a body of the valve drive rocker is made of an iron-based metal material, and the other body is made of a material different from the iron-based metal material, heat treatment being not required in the different material; and

a switching portion which makes the valve drive rocker in a drive state by rendering the cam follower rocker abut on the valve drive rocker, makes the valve drive rocker in a non-drive state by canceling the abutment, and is able to switch the valve drive rocker between the drive state and the non-drive state.

2. The variable valve device for the internal combustion engine according to claim 1 , wherein the switching portion includes:

a switching operation portion which is formed in the other body while having a cylinder and a piston, the cylinder being communicated with an oil passage of the rocker shaft, the piston being slidably inserted into the cylinder; and

an abutment which is formed in one of the bodies while being able to abut on the piston by the slide of the piston, and

a sleeve made of the iron-based metal material is provided in an inner surface of the cylinder.

3. The variable valve device for the internal combustion engine according to claim 2 , wherein the different material is a non iron-based metal material.

4. The variable valve device for the internal combustion engine according to claim 3 , wherein the non iron-based metal material is an aluminum material.

5. The variable valve device for the internal combustion engine according to claim 1 ,

wherein the cylinder extends in a direction substantially perpendicular to the rocker shaft.

6. The variable valve device for the internal combustion engine according to claim 1 , wherein the valve drive rocker includes:

a boss which is rotatably supported by the rocker shaft on both sides in which the cam follower rocker is located therebetween;

a pair of rocker arms wherein the arms extend linearly from the boss to the valve; and

a connecting arm which connects the arms at end portions of the extended arms.

7. The variable valve device for the internal combustion engine according to claim 6 , wherein the switching portion is able to switch a displacement of the cam follower rocker between transmission to the valve drive rocker and non-transmission to the valve drive rocker, and

a part of the switching portion on the valve drive rocker side is provided in the connecting arm.

8. The variable valve device for the internal combustion engine according to claim 7 , wherein the switching portion includes:

a switching operation portion which has a cylinder and a piston, the cylinder being communicated with an oil passage provided in the rocker shaft, the piston being slidably inserted into the cylinder; and

an abutment which is able to abut on the piston by the slide of the piston wherein one of the switching operation portion and the abutment is provided in the connecting arm.

9. A variable valve device for an internal combustion engine, the device comprising:

a camshaft which is rotatably provided in an internal combustion engine while having a cam;

a rocker shaft which is arranged next to the camshaft;

a valve driven by the cam;

a cam follower rocker which is rotatably provided in the rocker shaft, and is rocked by following the cam;

a valve drive rocker which is rotatably provided in the rocker shaft next to the cam follower rocker, and drives the valve, either a body of the cam follower rocker or a body of the valve drive rocker is made of an iron-based metal material, and the other body is made of a material different from the iron-based metal material, heat treatment being not required in the different material;

a switching portion which be able to switch the valve drive rocker between a drive state and a non-drive state,

wherein the valve drive rocker includes:

a boss which is rotatably supported by the rocker shaft on both sides in which the cam follower rocker is located therebetween;

a pair of rocker arms comprising the arms extend linearly from the boss to the valve; and

a connecting arm which connects the arms at end portions of the extended arms.

10. The variable valve device for the internal combustion engine according to claim 9 , wherein the switching portion is able to switch a displacement of the cam follower rocker between transmission to the valve drive rocker and non-transmission to the valve drive rocker, and

a part of the switching portion on the valve drive rocker side is provided in the connecting arm.

11. The variable valve device for the internal combustion engine according to claim 10 , wherein the switching portion includes:

a switching operation portion which has a cylinder and a piston, the cylinder being communicated with an oil passage provided in the rocker shaft, the piston being slidably inserted into the cylinder; and

an abutment which be able to abut on the piston by the slide of the piston, and

one of the switching operation portion and the abutment is provided in the connecting arm.