JPS626357Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a closed butterfly valve.

In general, butterfly valves are small, lightweight, have a simple structure, and require little opening/closing force, so they have a wide range of applications and are used in a variety of applications.

However, the butterfly valve has a drawback in that it is extremely difficult to achieve complete contact between the valve body and the valve body due to its structure, and some fluid leaks even in the fully closed state. Of course, so-called sealed butterfly valves that prevent such leakage are also in practical use, but such sealed valves have drawbacks such as a complex structure, high manufacturing costs, and easy failure. ing.

The present invention was developed based on the above circumstances, and the purpose is to provide a butterfly valve that has a simple structure yet provides a satisfactory sealing structure, and also allows easy attachment and removal of the elastic sealing material. .

That is, in order to achieve the above purpose, the present invention
A circumferentially continuous groove is integrally formed on the outer circumferential surface of the valve body, bypassing the upstream side of the bearing part of the valve shaft, and an annular elastic seal is placed in this groove that tightly contacts the valve seat surface of the valve body in the fully closed state. It is characterized by being fitted with wood.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

In the figure, 1 is a valve box having a substantially short cylindrical shape. A fluid passage 16 having a circular cross section is formed inside the valve box 1, and fluid flows through the passage 16 in the direction of the arrow. Flange portions 2, 2 for connecting pipes are provided on the edge surfaces of the opening at both ends of the valve box 1, and a plurality of bolt insertion holes 3 are formed in each flange portion 2, 2 at equal pitches. An upper bearing part 4 is provided at the center of the upper part of the valve body 1, and a lower bearing part 7 is provided at the center of the lower part of the valve body 1, facing the bearing part 4. A valve shaft 11 is rotatably supported between the upper and lower bearing parts 4 and 7 in a direction perpendicular to the passage direction of the fluid passage 16. The upper end of the valve stem 11 passes through the upper bearing part 4 and is led out, and the upper bearing part 4 accommodates a packing 5 that ensures liquid tightness of the part through which the valve stem 11 is inserted. There is. The gasket 5 is held within the bearing portion 4 by a cover plate 6 so as not to come off.

A valve body 10 as shown in FIG. 2 is supported on the valve shaft 11. The valve body 10 has a disk shape with an outer diameter slightly smaller than the inner diameter of the valve seat surface 1a of the valve body 1, and the valve stem 11 passes through a valve stem hole 12 formed in the center thereof and extending in the vertical direction. Fixed. Therefore, when the valve shaft 11 is rotated, the valve body 10 is rotationally displaced within the fluid passage 16 to open and close the fluid passage 16. Further, the thickness of the valve body 10 is determined by the thickness of both side edges 10 on both sides of the valve shaft 11 as shown in FIGS. 2 and 3.
It is thinnest at points a and 10a, gradually increases in thickness as it approaches the center, and reaches its maximum thickness near the portion through which the valve stem 11 passes. A continuous groove 14 is integrally formed on the outer peripheral surface of such a valve body 10 over the entire circumference. This groove 14 draws a gentle curve near the insertion part of the valve stem 11, and the upstream side of the valve stem 11,
That is, it is provided so as to bypass the pressure receiving surface A side of the valve body 10. An elastic annular sealing material such as an O-ring 15 is fitted into the groove 14 . This O-ring 15 protrudes beyond the outer circumferential surface of the valve body 10, and is adapted to tightly contact the valve seat surface 1a of the valve body 1 to maintain liquid or airtightness when the valve body 10 is fully closed.

According to the butterfly valve having such a configuration, the groove 14 that bypasses the upstream side of the valve shaft 11 and continues in the circumferential direction is provided on the outer circumferential surface of the valve body 10. The ring 15 is continuously provided around the entire circumference of the valve body 10 without being cut in the middle. Therefore, the gap between the valve body 10 and the valve seat surface 1a caused by thermal expansion of the valve body 1 and the valve body 10 can be filled over the entire circumference, and the groove 14 is filled with O2.
The valve body 1 can be easily assembled by simply fitting the ring 15.
A complete seal can be achieved when the valve is fully closed at zero. In addition, the O-ring 15 is such that the valve stem 11 is connected to the valve body 10.
Since the part through which the valve is inserted passes upstream of the valve shaft 11, when the valve shaft 11 is fully closed, the bearing parts 4 and 7 of the valve shaft 11 as well as the seals that ensure the fluid tightness of the bearing part 4 are inserted. 5 can be completely shielded from the fluid.

Therefore, it is possible to reliably prevent fluid from leaking from the bearings 4 and 7 when the bearings are fully closed, contributing more effectively to the above-mentioned complete sealing.

Moreover, since the groove 14 on the outer circumferential surface of the valve body 10 draws a gentle curve and detours around the valve stem 11, it is extremely easy to fit an O-ring, and it is especially suitable for use with hard seals for high temperatures. Even when fitting the ring, there is an advantage that the fitting operation can be easily performed. In addition, due to long-term use, O-ring 1
Even if the O-ring 5 deteriorates over time, it can be replaced with a new O-ring 15 very easily, so that a perfect seal can always be achieved. Furthermore,
The valve body 10 does not directly contact the valve seat surface 1a of the valve body 1,
Since it always contacts the valve seat surface 1a via the O-ring 15, the valve seat surface 1a will not wear out and the valve body 10 will not be damaged.

Note that FIGS. 5 to 7 show other embodiments of this invention, and the valve body 10 according to this embodiment has a disk shape with a uniform thickness, and only around the valve stem hole 12. A columnar thick portion 29 is formed. An annular groove 30 (only the upper side is shown) is formed on the outer circumferential surface of the valve body 10 around the valve stem hole 12, and a linear groove 14 is formed on the outer circumference by cutting through the annular groove 30. It is placed along the surface.
That is, these grooves 14 and 30 are continuous over the entire circumference of the outer peripheral surface of the valve body 10. An O-ring 15 is fitted into these grooves 14 and 30, avoiding the valve shaft 11. This O-ring 15
In the annular groove 30, the valve body 10
The groove 30 is fitted through a semicircular portion on the pressure receiving surface A side, and a semicircular filling member 33 shown in FIG. It is included. The filling member 33 is made of the same material as the valve body 10, for example, and is shaped so that the inner circumferential side protrudes more than the outer circumferential side, as shown in the figure.

The annular groove 30 is formed in an annular shape for ease of machining, and is formed in a semicircular shape only in the upstream portion of the valve shaft 11 where the O-ring 15 is normally fitted. It is good as long as it is formed.

However, in this embodiment as well, the O-ring 15
Since the valve body 10 is provided continuously over the entire circumference of the valve body 10 without being interrupted in the middle, it is possible to completely close and seal the valve body 1 when the valve body 10 is fully closed.

Note that the sealing material is not limited to the O-ring 15 mentioned above, but in short, it has a certain degree of elasticity, and when fully closed, the valve seat surface 1a of the valve body 1
It suffices if it can be in close contact with.

According to the present invention described in detail above, a circumferentially continuous groove is integrally formed on the outer peripheral surface of the valve body, and an annular elastic sealing material that tightly contacts the valve seat surface of the valve body in the fully closed state is attached to this groove. Once fitted, the elastic sealing material can fill the gap between the valve body and the valve seat surface over the entire circumference. Moreover, since the groove bypasses the upstream side of the bearing part of the valve stem, when the valve body is fully closed, the elastic sealing material that fits into the groove completely protects the bearing part of the valve stem from fluid. This can reliably prevent fluid from leaking from the bearing. Therefore, complete sealing can be achieved with a simple configuration. Further, since the elastic sealing material can be simply fitted into the groove, there is no need to disassemble the valve body when attaching and removing the sealing material, and there is an advantage that the attachment and detachment work can be performed extremely easily.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of this invention, in which Figure 1 is a longitudinal sectional view of a butterfly valve, Figure 2 is a perspective view of the valve body, and Figure 3 is a line taken along the line shown in Figure 1. 4 is an enlarged sectional view of the portion shown in FIG. 3, FIGS. 5 to 7 show other embodiments of the invention, FIG. 5 is a perspective view of the valve body, and FIG. The figure is a top view of the valve body, and FIG. 7 is a perspective view of the filling member. 1... Valve box, 4, 7... Bearing part, 10... Valve body, 11
... Valve stem, 14... Groove, 15... O-ring (sealing material), 16... Fluid passage, 30... Annular groove (groove).

Claims (1)

[Scope of utility model registration request] In a butterfly valve in which a valve stem is rotatably attached to a bearing part of a valve body, and a disc-shaped valve element provided on the valve stem opens and closes a fluid passage within the valve body, the outer circumferential surface of the valve element is A circumferentially continuous groove is integrally formed around the upstream side of the bearing part of the valve stem, and an annular elastic sealing material that tightly contacts the valve seat surface of the valve body in the fully closed state is fitted into this groove. A butterfly-shaped valve featuring