Abstract: A link couples a support body and a valve body in a first arrangement where a first link-forming member is rotationally movably supported by the support body and in which a second link-forming member is rotationally movably supported by the valve body. The link includes: a link length that is a length of the first link-forming member, as measured between a rotation axis with respect to the support body and a rotation axis with respect to the second link-forming member; and a link length that is a length of the second link-forming member, as measured between a rotation axis with respect to the valve body and a rotation axis with respect to the first link-forming member. The link lengths differ from each other. The link is also configured to enable coupling between the support body and the valve body in a second arrangement inverted with respect to the first arrangement.

Abstract: A valve device for an exhaust flow passage includes a toggle mechanism, in which a support-side link member and a valve-side link member form a first stopper mechanism and a second stopper mechanism. The first stopper mechanism is configured to limit a link angle formed by the support-side link member and the valve-side link member by abutment of a first support-side stopper portion formed in the support-side link member and a first valve-side stopper portion formed in the valve-side link member against each other. The second stopper mechanism is configured to limit the link angle by abutment of a second support-side stopper portion formed in the support-side link member and a second valve-side stopper portion formed in the valve-side link member.

Abstract: A link couples a support body and a valve body in a first arrangement where a first link-forming member is rotationally movably supported by the support body and in which a second link-forming member is rotationally movably supported by the valve body. The link includes: a link length that is a length of the first link-forming member, as measured between a rotation axis with respect to the support body and a rotation axis with respect to the second link-forming member; and a link length that is a length of the second link-forming member, as measured between a rotation axis with respect to the valve body and a rotation axis with respect to the first link-forming member. The link lengths differ from each other. The link is also configured to enable coupling between the support body and the valve body in a second arrangement inverted with respect to the first arrangement.

Abstract: A valve device for an exhaust flow passage includes a toggle mechanism, in which a support-side link member and a valve-side link member form a first stopper mechanism and a second stopper mechanism. The first stopper mechanism is configured to limit a link angle formed by the support-side link member and the valve-side link member by abutment of a first support-side stopper portion formed in the support-side link member and a first valve-side stopper portion formed in the valve-side link member against each other. The second stopper mechanism is configured to limit the link angle by abutment of a second support-side stopper portion formed in the support-side link member and a second valve-side stopper portion formed in the valve-side link member.

Abstract: A valve device includes a butterfly valve and a first link member each supported by a stay so as to be rotationally movable about a first rotation axis and a second rotation axis, respectively, a second link member supported by the butterfly valve so as to be rotationally movable about a third rotation axis, and a spring to bias the butterfly valve in a valve closed direction. The first link member and the second link member are connected to each other so as to be mutually rotationally movable about a fourth rotation axis. An angle formed by a first link line connecting the second rotation axis and the fourth rotation axis to each other and a second link line connecting the third rotation axis and the fourth rotation axis to each other is formed to be the largest when the butterfly valve is in a valve closed state.

Abstract: A valve device includes a butterfly valve and a first link member each supported by a stay so as to be rotationally movable about a first rotation axis and a second rotation axis, respectively, a second link member supported by the butterfly valve so as to be rotationally movable about a third rotation axis, and a spring to bias the butterfly valve in a valve closed direction. The first link member and the second link member are connected to each other so as to be mutually rotationally movable about a fourth rotation axis. An angle formed by a first link line connecting the second rotation axis and the fourth rotation axis to each other and a second link line connecting the third rotation axis and the fourth rotation axis to each other is formed to be the largest when the butterfly valve is in a valve closed state.