JPH02127864U - - Google Patents

Description

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view showing an embodiment of the ball valve according to the present invention, Fig. 2 is a cross-sectional view taken along the - line arrow in Fig. 1, and Fig. 3 is a view when the ball in Fig. 2 is rotated by 90 degrees. 4 and 5 are explanatory diagrams showing the relationship between the radii R and r of the above embodiment, respectively. FIG. 6 is a sectional view showing a modification of the above embodiment. Figures 7 and 8 are longitudinal sectional views of the ball according to the present invention, Figure 9 is a vertical sectional view of a conventional top entry type ball valve, and Figure 10 is a longitudinal sectional view of another conventional top entry type ball valve. FIG. 1...Valve body, 4...Ball accommodating part, 5...
... Distribution hole, 6 ... Ball, 7 ... Seat packing, 11 ... Fluid passage, 12 ... First curved surface area, 1
3...Second curved surface area, R...Radius of the first curved surface area, r...Radius of the second curved surface area, a...Amount of eccentricity.

Claims (1)

[Claims for Utility Model Registration] 1. A valve body having a ball accommodating portion and a plurality of fluid passages; a valve body that is rotatably accommodated in the ball accommodating portion and extends perpendicularly to the rotation axis; A ball valve comprising: a ball having a communication hole formed at a position facing the fluid passage; and a seat gasket interposed between the valve body and the ball so as to surround the fluid passage. In the ball, a first curved surface region having the communication hole formed therein and a second curved surface region connected to the first curved surface region are respectively formed at positions facing the sheet packing by rotation of the ball. , the first curved surface area is a curved surface with a radius R centered on the rotation axis, the second curved surface area is a curved surface with a radius r centered on a position eccentric from the rotation axis by a predetermined amount, and the radius A ball valve characterized in that R and r are selected such that the first curved surface region does not substantially compress the seat packing and the second curved surface region compresses the seat packing. 2 The first and second curved surface regions are offset from each other by about 90 degrees, the radii R and r and the predetermined amount a satisfy the condition (R-a)<r≦R, and the eccentric amount a is about 0. 2. The ball valve of claim 1, having a diameter of .05 to 2.5 mm. 3. A valve body having a ball accommodating portion and a plurality of fluid passages; the valve body is rotatably accommodated in the ball accommodating portion along with a rotation axis, and a communication hole extending perpendicularly to the rotation axis faces the fluid passage. In the ball valve, the ball is provided with a ball that is perforated at a possible position; and a seat gasket that is interposed between the valve body and the ball so as to surround the fluid passage, and the ball has the fluid passage. A first curved surface region having holes formed therein and a second curved surface region connected to the first curved surface region are respectively formed at positions facing the sheet packing by the rotation of the ball, and the first curved surface region is formed in the above-mentioned shape. It is a curved surface with a radius R centered on the rotation axis, the second curved surface region is elliptical, and the first curved surface region and the second curved surface region are such that the former does not substantially compress the sheet packing. A ball valve, characterized in that the latter is selected to compress the seat packing. 4. The ball valve of claim 3, wherein the first and second curved areas are offset from each other by about 90 degrees.