Intake device

1. An intake device including a valve rotatably provided through a shaft, for opening and closing an intake passage that air flows in, wherein the valve is arranged in a manner that, in a fully closed state thereof, the valve extends orthogonal to a direction that the intake passage extends in, and wherein the valve is rotated around the shaft from the fully closed state to open the intake passage in a manner that one end of the valve moves upstream and another end thereof moves downstream, to thereby control a flow rate of the air supplied into an internal combustion engine through the intake passage,

the intake device comprising a flow regulating structure configured to guide, downstream, part of the air flowing in the intake passage, the flow regulating structure being disposed downstream of the valve and arranged to face the one end of the valve in the fully closed state, the flow regulating structure extending along the intake passage and being connected to an inner peripheral surface of the intake passage,

the flow regulating structure including: a round tube body having a circular cross section with a smaller diameter than the intake passage, the round tube body extending along the intake passage with the diameter thereof unchanged and having an outer peripheral surface connected to the inner peripheral surface of the intake passage; and a supporting body that connects the inner peripheral surface of the intake passage and the outer peripheral surface of the round tube body, the flow regulating structure being configured and arranged in a manner that, when the valve is fully open, the flow regulating structure resides in a position that is radially outside of, and out of contact with, the another end of the valve,

the intake device further comprising a throttle body including the valve, and an intake pipe disposed downstream of the throttle body and connected to the internal combustion engine, wherein the intake passage is formed to pass through from the throttle body into the intake pipe, and the flow regulating structure is disposed at an upstream end of the intake passage in the intake pipe,

the round tube body including: a first semicircular arc separated from the inner peripheral surface of the intake passage; and a second semicircular arc connected to the inner peripheral surface of the intake passage, wherein the first semicircular arc is entirely separated from the inner peripheral surface of the intake passage, and the second semicircular arc includes a connected portion connected to the inner peripheral surface of the intake passage and unconnected portions not connected to the inner peripheral surface of the intake passage, the unconnected portions being positioned on both sides of the connected portion in a circumferential direction of the round tube body.

2. The intake device according to claim 1 , wherein the supporting body is shaped like a plate and formed to extend in a radial direction of the intake passage from an outer peripheral surface of the first semicircular arc of the round tube body.

3. The intake device according to claim 1 , wherein the supporting body includes another round tube body that is different from the round tube body.

4. The intake device according to claim 3 , wherein the another round tube body comprises at least two other round tube bodies and the flow regulating structure includes a second supporting body that connects the other round tube bodies to each other.

5. The intake device according to claim 1 , wherein the diameter of the round tube body is set to a maximum length that does not allow the valve to come in contact with the round tube body in a range that the valve rotates in.

6. The intake device according to claim 1 , wherein the supporting body connects to the first semicircular arc of the round tube body at a position diametrically opposed to the connected portion of the semicircular arc of the round tube body.