JP2523948Y2 - Center type butterfly valve body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a center type butterfly valve in which a valve body is supported by a valve stem mounted on a central axis, and in particular, the valve stem is vertically moved. The present invention relates to a two-part valve stem that is divided into two parts and a central butterfly valve.

[Conventional technology]

Conventionally, as shown in a front view of FIG. 4 and a side view of FIG. 5, a valve stem two-part central type butterfly valve is constituted by two valve stems (not shown) in which a valve body 1 is vertically divided into two parts. An upper boss 3 having a thickness greater than that of the disc portion 2 is supported by a body (valve body) (not shown).
And the lower boss 4 respectively.

[Problems to be solved by the invention]

As shown in FIG. 6 (cross-sectional view taken along line XX of FIG. 4), the above-described conventional valve stem two-part central type butterfly valve is operated by a pressure from a high-pressure type fluid when the valve is operated and when closing and pressurizing. And y
Axis, i.e. the moment M _y about the axis of the street valve stem axis direction the valve element centers, as shown in FIG. 5, x-axis, that is the moment around the axis perpendicular to the street valve stem axis of the valve body center M _x occurs.

Above with respect to both moments M _y and M _x, this type valve stem 2
If the partial butterfly valve is generally than bending stress sigma _y generated by M _y, it is to increase the value of the bending stress sigma _x generated by the M _x, overload, such as water hammer is applied,
As shown in FIG. 7, there is a problem that bending fracture occurs in the XX section.

Stress sigma _x bent in the sectional view taken along line X-X is where _{σ x = M x / Z x} , Z x is a section modulus at section X-X, a Z _x = DT ^2/6.

As described above, in order to reduce the bending stress σ _x , Z _x may be increased. For that purpose, the value of the valve body diameter D or the valve body thickness T may be increased. However, since the value of the diameter D cannot be changed for ensuring the sealing property, the value of the thickness T of the valve body must be increased.

As a result, the volume of the disc portion 2 of the valve element increases as a whole, and the weight increases. In addition, there is a problem that the rate of increase in the weight of the valve body is large.

The present invention does not increase the weight and prevents bending failure especially in the XX cross section along the x-axis of the valve body even when an overload such as a water hammer action is applied. It is an object of the present invention to provide a two-part central type butterfly valve having a reduced valve body fluid resistance at the time of opening.

[Means for solving the problem]

In order to achieve the above object, the present invention inserts and fixes two valve stems, which are divided into upper and lower portions, into upper and lower boss portions formed thicker than the disc portion of the valve body. In the center type butterfly valve of the two-way valve stem, a reinforcing plate joined to both upper and lower bosses in the valve stem direction and having substantially the same width as both bosses is provided integrally on both sides of the valve body. It is characterized by.

[Action]

Since the present invention is configured as described above, the section modulus Z _x ′ in the XX section along the x axis of the valve body is Becomes

Here, 1g: an axis g parallel to the x axis passing through the centroid g of the reinforcing plate
K: the distance between the x-axis and the g-axis A: the cross-sectional area of the reinforcing plate As described above, since the cross-sectional modulus Z _x ′ is affected by the function of the square of k, the cross-sectional area A is Even if it does not increase too much, it is possible to increase the value of Z _x 'by increasing the value of k.

Therefore, rather than increasing the thickness of the valve disc, the reinforcing plates are integrally provided on both sides by connecting the upper and lower bosses formed thicker than the valve disc in the valve stem direction. This can suppress the overall weight increase and ensure the necessary strength.

Further, since the reinforcing plate has a simple structure which is joined to the upper and lower boss portions and has substantially the same width as the both boss portions, the fluid resistance on both sides of the valve body when the valve is opened can be reduced. .

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

FIG. 1 is a front view of a valve body showing one embodiment of the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a sectional view taken along the line XX of FIG. The same reference numerals as those shown in FIG. 6 indicate the same or similar parts.

In the figure, the valve body 1 is provided with an upper boss 3 and a lower boss 4 which are thicker than the disk portion 2 in order to mount a valve stem (not shown) which is divided into upper and lower parts. ) Is no different.

In this embodiment (the present invention), both upper and lower bosses 3 in the valve stem direction are used.
And 4 are straddled, and reinforcing plates 5 having substantially the same width as both bosses are joined and attached to both sides of the valve body 1.

Next, to explain the action, moment of inertia I _x1 is the x-axis of the disc portion ^{_{2, I x1 = DT 3/}} 12 second moment I _x2 to x-axis of the reinforcing plate 5, I _x2 = I _g + k ² A Here, _Ig is a second moment of area with respect to the g axis (the axis passing through the centroid g of the reinforcing plate 5 and parallel to the x axis). k is the distance between the x-axis and the g-axis. A is the cross-sectional area of the reinforcing plate 5. A = bt. Therefore, the resultant second moment of area I _x around the x-axis is I _x = I _x1 + 2 × I _x2 = DT ³ / 12 + 2 ( _Ig + k ² A) The section modulus Z _x ′ is (Here, e: maximum distance to the periphery of the reinforcing plate).

According to this embodiment, the reinforcing plate 5 is joined and attached to both sides of the valve body 1 so as to straddle the upper and lower boss portions 3 and 4 so that the sectional modulus Z of the valve body 1 in the XX section is provided. _x ′
Is affected by the function of the square of k. Therefore, even if the cross-sectional area A does not increase so much, the value of k, that is, the distance between the x-axis and the g-axis is increased, so that the cross-sectional coefficient Z _x 'Can be increased.

Therefore, the provision of the reinforcing plate 5 suppresses the overall weight increase and makes it possible to secure necessary strength, rather than increasing the thickness T of the valve disc portion 2.

Further, since the reinforcing plate 5 has a simple structure in which the reinforcing plate 5 is joined and attached to both sides of the valve body 1 and is formed to have substantially the same width as both boss portions, the fluid resistance on both sides of the valve body when the valve is opened is also reduced. Less is needed.

[Effect of the invention]

As described above, according to the present invention, in the center type butterfly valve of the valve stem bifurcated type, the reinforcing plate which is joined to both upper and lower bosses in the valve stem direction and has substantially the same width as the both bosses is provided. By being provided integrally on both sides of the body, the sectional modulus Z _x ′ in the XX section along the x-axis of the valve body is defined by the x-axis and the axis passing through the centroid of the reinforcing plate and parallel to the x-axis. Since it is affected by the function of the square of the distance k, the cross-sectional area does not increase so much.
Makes it possible to increase the value of the section modulus Z _x ′.

Therefore, without increasing the thickness of the valve disc portion, the increase in overall weight can be suppressed by the reinforcing plate, and the necessary reinforcement can be secured. In addition, these reinforcing plates joined to and attached to both boss portions formed thicker than the disc portion on both sides of the valve body have a simple structure formed to have approximately the same width as both boss portions. Therefore, the fluid resistance on both sides of the valve body when the valve is opened can be reduced.

[Brief description of the drawings]

1, 2 and 3 are a front view, a side view and a sectional view taken along line XX of FIG. 1, FIG. 4, FIG. 5 and FIG. The figure shows a valve stem 2 showing a conventional example.
XX sectional view of the front view, side view and FIG. 4 of the split valve body,
FIG. 7 is a side view showing a state in which a conventional valve element is bent and broken. DESCRIPTION OF SYMBOLS 1 ... Valve element, 2 ... Disk part, 3 ... Upper boss, 4 ... Lower boss,
5. Reinforcement plate.

Claims (1)

(57) [Scope of request for utility model registration] 1. A two-part valve stem of a two-part valve stem which is inserted into and fixed to two upper and lower boss portions formed thicker than a disk portion of a valve body, respectively. In a center type butterfly valve, a reinforcing plate joined to both upper and lower bosses in the valve stem direction and having substantially the same width as the both bosses is provided integrally on both sides of the valve body. Valve body.