| 摘要 |
PROBLEM TO BE SOLVED: To provide a valve device which can prevent the displacement of a valve-opening start angle even if a relative position between a valve opening and a seat opening is displaced to an axial direction.SOLUTION: A valve device changes a communication degree of a valve opening 1b and a seat opening 2b by turning a ball valve 1, is opened by the communication of the valve opening 1b and the seat opening 2b, and closed by the non-communication of the valve opening 1b and the seat opening 2b. A linear part α which is vertical to a turning direction of the ball valve 1 is arranged at a valve-opening start point of the valve opening 1b. By this constitution, even if a relative position between the valve opening 1b and the seat opening 2b is displaced to an axial direction by an assembling error, a dimension allowance or the like, the displacement of a valve-opening start angle can be prevented since a valve opening is started at the linear part α. Therefore, a variation of a flow rate caused by the displacement of the valve-opening start angle, and the reliability of flow rate control with respect to the valve device can be enhanced.SELECTED DRAWING: Figure 2 |
