| 摘要 |
PROBLEM TO BE SOLVED: To provide a technology that secures the sealability of a valve and inhibits wear of a valve body without using a housing having a special structure.SOLUTION: A butterfly valve has: a housing having a passage in which a fluid passes; a rotary valve shaft; and a valve body which is provided in the passage, changes a distance from the valve shaft according to a rotation angle of the valve shaft, and has a discoid shape. A distance between the valve body and the valve shaft which is formed when the valve body is in a first position where the valve body blocks the passages is longer than a distance between the valve body and the valve shaft which is formed when the valve body is in a second position where the valve body does not block the passage.SELECTED DRAWING: Figure 4 |
