Patent ID: 7404384

Claim:
A variable valve device for an internal combustion engine comprising: a camshaft which is rotatably provided in a body of an internal combustion engine; a pair of rocker shafts which is arranged next to the camshaft; an inlet valve which is driven by rotation of the camshaft; an exhaust valve which is driven by the rotation of the camshaft; a first hydraulic rocker arm which is rockably supported by one of the rocker shafts, and is able to switch drive of one of the inlet valve and the exhaust valve at least between a normal drive state and a first mode which is different from the normal drive state; a second hydraulic rocker arm which is rockably supported by the other rocker shaft, and is able to switch drive of the other of the inlet valve and the exhaust valve at least between the normal drive state and the first mode which is different from the normal drive state; a first switching oil passage which is formed along an axial direction in one of the rocker shafts, the first rocker arm being switched to the first mode by applying oil pressure to the first rocker arm through the first switching oil passage; and a second switching oil passage which is formed along an axial direction in the other rocker shaft, the second rocker arm being switched to the first mode by applying oil pressure to the second rocker arm though the second switching oil passage, a plurality of relay oil passages communicating the first switching oil passage and the second switching oil, the first switching oil passage, the second switching oil passage, and the relay passages being formed in a ladder shape each relay oil passage releasing oil pressure in the second switching oil passage to the first switching oil passage.