To reduce a fluid flow rate passing through clearance between its member, while constituting a flow passage opening-closing member in a noncontact state in full closure.
This throttle valve device 1 is used in an intake air passage of an engine; and has a body 3 including a bore 2, two rotary valve plates 4 and 5 rotatably arranged in the body 3 by crossing the bore 2 and mutually arranged in parallel in a noncontact state, a first motor 6 and a second motor 7 for rotating the respective rotary valve plates 4 and 5. The two rotary valve plates 4 and 5 include throttle holes 4a and 5a capable of mutually overlapping by rotation. The overlapping area of the two throttle holes 4a and 5a is changed by relatively rotating the two rotary valve plates 4 and 5 for changing opening. While the two throttle holes 4a and 5a keep an apparent full closure state of becoming nonoverlapping, the two rotary valve plates 4 and 5 are mutually synchronously rotated. A speed of synchronous rotation is changed for further finely adjusting an air flow rate of the apparent full closure state.
Ikuo Yamanaka
Akika Okado