JP-7854858-B2 - Butterfly valve

JP7854858B2JP 7854858 B2JP7854858 B2JP 7854858B2JP-7854858-B2

Inventors

野口拓馬
佐藤栄治
大川丈典

Assignees

オイレス工業株式会社

Dates

Publication Date: 20260507
Application Date: 20220526

Claims (4)

A butterfly valve that opens and closes an exhaust pipe that communicates with the exhaust port of an engine, A valve plate provided inside the exhaust pipe, A valve stem that crosses the exhaust pipe and holds the valve plate, A bearing unit that slidably supports the valve shaft, having an annular sealing bush and a support bush separately into which the valve shaft is inserted, The system comprises a housing that is attached to the exhaust pipe and houses the bearing unit located outside the exhaust pipe, The support bush of the bearing unit is positioned between the housing and the sealing bush of the bearing unit, and the outer circumferential surface of the support bush abuts against the housing. The sealing bush of the bearing unit slidably contacts the housing with its outer circumferential surface and contacts the flange of the valve shaft with the valve shaft facing surface of the sealing bush. A butterfly valve characterized in that the sealing bush of the bearing unit slides against the housing on its outer circumferential surface when the sealing bush and the flange of the valve shaft are fixed together .
The sealing bush of the bearing unit is softer than the support bush of the bearing unit. The butterfly valve according to claim 1, characterized in that the inner diameter of the sealing bush is greater than or equal to the inner diameter of the support bush.
A gap is formed between the support bush and the valve stem. The butterfly valve according to claim 1, characterized in that the inner diameter of the sealing bush is larger than the inner diameter of the support bush.
The butterfly valve according to any one of claims 1 to 3, characterized in that the coefficient of linear expansion of the support bush and the coefficient of linear expansion of the housing are substantially the same.

Description

This invention relates to a butterfly valve, and more particularly to a butterfly valve for opening and closing an exhaust pipe that communicates with the exhaust port of an engine. Conventionally, an exhaust device (butterfly valve) for controlling the exhaust gas flow in an exhaust pipe communicating with the exhaust port of a motorcycle engine is known. This device comprises a valve body (valve plate) positioned within the exhaust pipe, a valve stem fixed to or integrally formed with the valve body and positioned to traverse the exhaust pipe, and a pair of bearing members rotatably supporting both ends of the valve stem in the axial direction, with the valve body rotating around the valve stem axis (for example, Patent Document 1). Japanese Patent Publication No. 2008-169797 (see, for example, Figure 5) A perspective view of an exhaust pipe incorporating a butterfly valve, which is a first embodiment of the present invention.Longitudinal section view of Figure 1.Enlarged view of III in Figure 2.Enlarged view of IV in Figure 3.An enlarged cross-sectional view of the main part of a butterfly valve, which is a second embodiment of the present invention.An enlarged cross-sectional view of the main part of a butterfly valve, which is a third embodiment of the present invention.An enlarged cross-sectional view of the main part of a butterfly valve, which is a fourth embodiment of the present invention.An enlarged cross-sectional view of the main part of a butterfly valve, which is a fifth embodiment of the present invention.Enlarged view of IIIVB in Figure 8A.Exploded perspective view of the bearing unit in the butterfly valve of the sixth embodiment of the present invention.Enlarged cross-sectional view of the main part of the butterfly valve in the IXB-IXB section of Figure 9A. The present invention relates to a butterfly valve for opening and closing an exhaust pipe communicating with the exhaust port of an engine, comprising: a valve plate provided in the exhaust pipe; a valve shaft that traverses the exhaust pipe and holds the valve plate; a bearing unit that slidably supports the valve shaft by having an annular sealing bush and a support bush separately inserted into the valve shaft; and a housing that is attached to the exhaust pipe and houses the bearing unit which is located outside the exhaust pipe, wherein the support bush of the bearing unit is positioned between the housing and the sealing bush of the bearing unit and abuts the housing with the outer surface of the support bush; the sealing bush of the bearing unit slidably abuts the housing with the outer surface of the sealing bush and abuts the flange of the valve shaft with the valve shaft facing surface of the sealing bush; and the sealing bush of the bearing unit slides with the housing with the outer surface of the sealing bush when the sealing bush and the flange of the valve shaft become fixed , so that exhaust gas is less likely to leak out of the exhaust pipe even under high back pressure, and the seal bush continues to function even if the sealing bush and the flange of the valve shaft become fixed . Any specific embodiment of the present invention is acceptable as long as these are ensured. For example, the butterfly valve in the present invention is installed in an exhaust pipe that communicates with the exhaust port of an engine of a four-wheeled vehicle. However, the butterfly valve of the present invention is not limited to four-wheeled vehicles; it may also be installed in a motorcycle, and the four-wheeled vehicle may be a gasoline vehicle or a diesel vehicle. In other words, the engine with the connected exhaust pipes can be either a gasoline engine or a diesel engine. Furthermore, while diesel engines used in trucks generally have higher back pressure than gasoline engines used in passenger cars, the butterfly valve according to the present invention can sufficiently suppress the leakage of exhaust gas outside the exhaust pipe.