JP2527277Y2 - Screw-in type butterfly valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention mainly relates to a small-diameter butterfly valve used for opening and closing a pipeline of any fluid such as powder, liquid, and gas.

[Problems to be solved by conventional technology and device]

Conventionally, the basic structure of a butterfly valve is roughly divided into a central valve shown in FIG. 4 and an eccentric valve shown in FIG.
In each case, a hollow cylindrical main body (valve main body) 1 made of a metal or non-metal material, a disc-shaped valve body 2 made of a metal or non-metal material rotatably supported in the main body 1, An annular valve seat 3 made of an elastic material is interposed between an inner peripheral surface of the main body 1 and a peripheral portion of the valve body 2, and the valve is opened and closed by the valve body 2 and a valve stem extending radially outward. 4 is performed through a drive mechanism (not shown).

The most significant feature of the butterfly valve described above is that other globe valves,
Compared to general-purpose valves such as gate valves, it is lightweight and small, and adopts a flangeless wafer type without flanges on both sides. The connection with piping is clamped between pipe flanges by bolts etc. Connected. In the wafer type connected by such a pipe flange, the minimum diameter of the valve is 40 to 50 mm as compared with the conventional one, and it is said that there is a difficulty in the above connection method when the diameter is smaller than these. . The reasons are that the number of man-hours for piping and the shape after piping are increased, and that the cost is low. On the other hand, these small-diameter valves are said to have sufficiently exhibited their performance even with the above-mentioned general-purpose valves. However, recently, in terms of operability of operators and ease of maintenance and inspection in the same piping system, the same piping system has been used. There is a great demand for a valve of the same type, that is, a butterfly valve.

At present, there are mainly two types of connection of valves for handling fluids which are used in large quantities without danger and are generally used in large quantities. That is, for small diameters (generally less than 40 to 50 mm), the “screw-in type” is adopted, and for small / medium diameters (generally 40 to 50 mm or more), the “flange type” is adopted.

Valve connections other than the above include union type (for water supply and drainage), brazing type (for copper piping such as hot water supply), socket type,
There are spigot type (all for water supply) etc. Also, for dangerous high temperature and high pressure related to nuclear power, gas and electric power, insertion welding type (for small diameter) and butt welding (for medium and large diameter) etc. There is.

According to JIS, the flange type specifies a nominal diameter of 10 mm or more.
50 mm or more. Further, those having a diameter smaller than the above-mentioned diameter are connected by tapered pipe threads.

In recent years, butterfly valves have also shown remarkable growth in quality, performance, operability, economy, reliability, and the like, and there is a great demand for reducing the diameter of the screw-type butterfly valve from the above-described piping system.

SUMMARY OF THE INVENTION An object of the present invention is to provide a screw-in type butterfly valve which can be used to a small diameter so that the diameter range can be expanded and extended to a small diameter.

[Means for solving the problem]

In order to achieve the above object, the present invention provides an annular elastic member sandwiched between an axially divided pipe-threaded short portion and a split annular body disposed outside thereof. A valve element is provided via a valve seat, and in a butterfly valve for a small diameter, which mainly opens and closes a fluid passage by rotation of the valve element, a valve rod extending through the valve seat and driven from the outside is provided. The valve seat, which is provided integrally with the valve body and penetrated by the valve rod, is constituted by a deformed valve seat formed in a tapered shape having a convex cross section having upper and lower inclined side surfaces whose outer shape is inclined outward. The inner peripheral surface of the valve seat that is in pressure contact with the peripheral portion of the valve body is formed in a spherical seat shape that is synchronized with the rotation of the valve stem in the vicinity of the valve stem pivoting portion. Formed in a deformed hexagonal shape, provided with a plurality of convex bodies in the circumferential direction on the outer tapered surface, It is characterized by omitting the bar.

[Action]

Since the present invention is configured as described above, the two pipe screw-in short portions mounted from the left and right sides in a state where the butterfly valve is assembled are modified valve seats having upper and lower inclined side surfaces inclined outward. Opposite inner ends formed in advance with concave portions that fit into the convex hexagonal convex tapered portions of
Since these two pipe screw-in short parts are fitted into the convex taper part of the valve seat, the horizontal core easily comes out, and is properly clamped by the split annular body disposed outside, and the pressure resistance is improved. Becomes one with.

In this state, since the inner surface of the deformed valve seat and the peripheral portion of the valve body are pressed against each other by the spherical seat in the vicinity of the valve rod rotating portion, the pressure contact is not forcibly applied, and the rotation of the valve is smooth. It has excellent durability and pressure resistance.

When the valve is closed, the pressure (reaction force) generated at the deformed valve seat toward the center of the valve against the peripheral portion of the valve body formed in a spherical shape is supported by the valve body via a valve rod formed integrally with the valve body. In addition to this, the back is backed up by the fitting inner surface of the short screw portion of the pipe via the inclined side surface of the outer shape of the deformed valve seat, so that it effectively acts on the peripheral portion of the valve body. A strong sealing force is exerted, and the sealing effect at the press contact surface between the peripheral portion of the valve element and the deformed valve seat is maintained. On the other hand, when the valve is opened, the external shape of the deformed valve seat is formed in a convex tapered shape having upper and lower inclined side surfaces which are inclined outward and is fitted to a short screwed portion of the pipe, so that the valve seat is in a flow of fluid. Accordingly, the protrusion (escape) inward in the radial direction is prevented.

Also, since a plurality of convex bodies are provided in the circumferential direction on the outer tapered surface of the deformed valve seat, leakage from the back side of the deformed valve seat is prevented.

Further, when the valve stem is omitted below the valve body, the pressure loss (resistance) at the time of opening the valve is reduced, and this is particularly remarkable in the case of a small-diameter valve. Further, since the valve body is supported via a valve rod formed integrally with the small-diameter valve valve body, and
Working pressure or surface pressure (meaning the total pressure applied to the valve body)
Thus, the cantilever structure is sufficient for the valve body.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1A is a sectional view showing a closed state of a butterfly valve showing one embodiment of the present invention, and FIG. 1B is a front view of the same.

In the figure, a pipe threaded short portion 11 divided into two in the axial direction is inserted from the left and right so as to abut the inner end surface 11a, and the outside of the annular convex portion 11b including the inner end surface 11a is inserted. An annular annular main body 12 having an annular concave portion 12a fitted on the inner surface of the annular convex portion 11b is attached so as to surround the annular convex portion 11b, and the hexagonal hole bolt 13 is tightened to form the annular convex portion 11b. The two pipe screwing short portions 11 are connected to the contact end surface 1 via the inclined surfaces 12b formed on both the fitting side surfaces of the annular concave portion 12a.
1a is connected to hermetically so as to be integrated.

A valve body 15 integrated with a valve stem 14 is housed in a central portion of the both pipe screwing short portions 11 across the contact end surface 11a, and the valve stem 14 has a lower valve stem omitted. Only the upper valve stem 14 penetrating above the main body 12 has a cantilever structure.

When the valve is closed, an annular elastic valve seat 16 is provided on the inner surface of the pipe threaded short portion 11 which is in contact with the peripheral portion of the valve body 15.
As shown in FIG. 3, the valve seat 16 has a substantially deformed hexagonal cross section having upper and lower inclined side surfaces inclined outward.
The pressure contact portion between the valve body 16 and the peripheral edge of the valve body 15 forms a spherical seat 16a concentric with the center O of the valve, and the hole 16b through which the valve rod 14 integral with the valve body 15 penetrates is formed by a cylinder. The center of the part has a conical shape, and the tightening force at the time of valve stem insertion is increased to prevent leakage due to rotation of the valve stem.

Also, upper and lower inclined side surfaces 16d inclined outwardly of the valve seat 16.
A plurality of circumferentially extending convex bodies 16c are formed on the outer surfaces of the pressure fluid and the pressure fluid 16e so that the pressure fluid exerts a labyrinth effect (pressure reduction effect) during use so as to prevent leakage of the pressure fluid. I have. However, at the time of assembling the valve, the convex body 16c is compressed by the inner surface of the fitting with the pipe screwing short portion 11, and the first
It becomes flat as shown in FIG.

In addition, as shown in FIG.
Shading a on the outer and inner surfaces of the pipe screwing short section 11 and the main body 12
The anti-corrosion measures indicated by are indicated. However, it goes without saying that it is not applied to the screw portion 11c. In addition, nylon coating, resin coating, nickel plating, etc. are used for the above anticorrosion measures.

Also, the short outer shape 11d of the threaded portion 11c of the pipe screwed short portion 11
As shown in FIG. 1 (b), has an octagonal shape, which is convenient for pipe-proof work (screw-in).

With the above configuration, when assembling the valve, the valve seat
16 is a slightly deformed state, and inserts the square tip of the valve rod 14 formed integrally with the valve body 15 radially outward from the inner diameter direction of the valve seat 16, and moves the valve body 15 to the valve seat 15. Assemble within 16. At this time, the outer diameter of the valve body 15 is slightly larger than the inner diameter of the valve seat 16, and the difference in the dimensions seals the fluid pressure. Therefore, the outer diameter of the valve seat 16 in the assembled portion is slightly extended outward.

In addition, the deformed hexagonal shape of the valve seat 16 allows the horizontal core of the two pipe screw-in short portions 11 to easily come out, tighten the annular annular body 12 with the hexagonal bolt 13 and clamp it from above and below. The cores in the horizontal and vertical directions are aligned with each other, and the assembly is completed.

Also, the length between both outer ends of both pipe screwing short portions 11,
In other words, the dimension 1 between the valve faces (FIG. 2)
Are formed by abutment with each other, at which point the valve seat
16 is slightly compressed in the horizontal direction, and ground leakage from the back side of the valve seat is prevented by the annular convex body 16c in the circumferential direction.

Further, since the pressure contact portion between the inner surface of the valve seat 16 and the peripheral portion of the valve body 15 forms a concentric spherical seat 16a including the vicinity of the valve rod rotating portion, the rotation of the valve body is smooth, durable and pressure resistant. It has excellent resistance and does not require excessive pressure.

Further, when the valve is closed, the valve element 1 generated on the spherical seat 16a of the elastic valve seat 16 is formed.
The reaction force b toward the center O of the valve against the spherical periphery of 5 is
Together with the fact that the valve element is supported via a valve rod formed integrally with the valve element, the inner surface of the pipe screwing short portion 11 is formed through the inclined side face 16d of the tapered valve seat 16 having a hexagonal shape. Therefore, the reaction force effectively acts on the peripheral edge of the valve body and exerts a strong sealing force, thereby reliably preventing leakage from the peripheral edge of the valve body when the valve is closed. Can be.

On the other hand, when the valve is open, the inclined side surface on the inner side of the convex tapered portion
16e prevents the fluid flowing in the main body from protruding (escape) inward in the radial direction.

Further, in this embodiment, the lower valve stem is omitted to form a cantilever structure. However, since the valve is a small-diameter valve, it can sufficiently withstand the surface pressure and requires less pressure resistance when the valve is opened. There are advantages. The surface pressure, that is, the total pressure applied to the valve element is, for example, π / 4D ² × 5 = 24.5 kg when the working pressure is 5 kg / cm ² in a valve having a diameter (D) of 25 mm.

[Effect of the invention]

As described above, according to the present invention, the pipe screwed short portion divided into two in the axial direction and the split annular body disposed outside the pipe screwed short portion are sandwiched. A valve having a valve element provided through an annular elastic valve seat, and a fluid passage is opened and closed by rotation of the valve element. A rod is provided integrally with the valve body, and the valve seat penetrated by the valve rod is formed in a tapered shape having a convex cross section having upper and lower inclined side surfaces having an outer shape inclined outward. By forming the inner peripheral surface in the shape of a spherical seat in the vicinity of the valve shaft rotating portion, the following effects are achieved.

(I) At the time of assembling the valve, the upper and lower inclined side surfaces inclined outwardly of the deformed valve seat easily come out of the cores of both the pipe screwing short portions,
The horizontal and vertical cores are aligned by fastening the split annular body,
It can be an integral type having pressure resistance.

(Ii) The accuracy of the inter-plane dimension of the valve and the compressive strength of the elastic valve seat are maintained by the abutment (joining) between the inner end faces of the pipe screwing short portions.

(Iii) The valve is closed by forming the outer shape of the valve seat penetrated by a valve stem integral with the valve body into a convex tapered shape having upper and lower inclined side surfaces inclined outward like a deformed hexagon. At this time, the pressure (reaction force) generated at the deformed valve seat toward the center of the valve against the peripheral edge portion of the spherical valve body is supported by the valve body via a valve rod formed integrally with the valve body. In conjunction with this, since the back surface is backed up by the fitting inner surface of the pipe screwing short portion through the inclined side surface of the outer shape of the deformed valve seat, it effectively acts on the valve body peripheral portion, and a strong seal is provided. It exerts force and maintains the sealing effect at the pressure contact surface between the valve element peripheral edge and the deformed valve seat, while the convex shape has upper and lower inclined side surfaces in which the outer shape of the deformed valve seat is outwardly inclined when the valve is opened The valve seat is formed into a tapered shape and fitted to the short section where the pipe is screwed in. It is prevented from projecting (escape) radially inwardly.

(Iv) Since the valve seat is formed in a spherical seat shape on the inner peripheral surface and in the vicinity of the valve rod rotating portion, the pressure contact does not take place when the valve body rotates,
Rotation is smooth, durability and pressure resistance are excellent, and torque is reduced.

(V) By providing a plurality of convex bodies in the circumferential direction on the outer tapered surface of the valve seat, leakage from the back side of the valve seat can be prevented.

(Vi) Since the valve element is supported via the valve rod formed integrally with the valve element, the lower portion of the valve rod can be omitted,
The structure is simplified as a small-diameter valve, and the pressure loss when the valve is opened can be reduced.

[Brief description of the drawings]

1 (a) is a side sectional view of a butterfly valve showing one embodiment of the present invention, FIG. 1 (b) is a front view, FIG. 2 is a side sectional view of the butterfly valve which has been subjected to anticorrosion measures, FIG. 3 is a sectional view of a main part, and FIGS. 4 and 5 are sectional side views of different types of butterfly valves of a conventional example. 11 ... Piping short section, 12 ... Split annular body, 13 ...
... Hexagon socket head bolt, 14 ... Valve stem, 15 ... Valve body, 16 ... Deformed valve seat, 16a ... Spherical seat, 16b ... Valve stem through hole, 16c ...
... convex, 16d, 16e ... inclined side surface, O ... center of valve.

Claims (2)

(57) [Scope of request for utility model registration] 1. An annular elastic valve seat which is sandwiched between an axially divided pipe screwing short portion divided into two in an axial direction and a split annular body disposed outside the pipe screwing short portion. In a butterfly valve for a small diameter, which is provided with a valve body and opens and closes a fluid passage by rotation of the valve body, a valve rod extending through the valve seat and driven from the outside is integrated with the valve body. And the valve seat penetrated by the valve stem is constituted by a deformed valve seat formed in a tapered shape having a convex cross section having upper and lower inclined side surfaces whose outer shape is inclined outward, and a valve body of the valve seat. A screw-type butterfly valve, wherein an inner peripheral surface pressed against a peripheral edge portion is formed in a spherical seat shape synchronized with rotation of a valve stem in the vicinity of a valve stem rotation part. 2. An annular elastically deformable valve seat is formed in a hexagonal shape with a deformed cross section, and a plurality of convex bodies are provided circumferentially on upper and lower inclined side surfaces inclined outward, and a valve is provided at a lower portion of the valve body. 2. The screw-type butterfly valve according to claim 1, wherein said valve has no rod.