JP3009319B2 - Ball valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to water in various industries,
The present invention relates to a ball valve used in a pipeline for transporting fluid such as oil, gas, chemicals or food, and more particularly, to a ball valve which can easily adjust a flow rate by changing an opening degree.

[0002]

2. Description of the Related Art A ball valve is normally a valve which can be opened and closed by being rotated by about 90 degrees, has a simple structure and is economical. However, since the flow rate changes abruptly according to the opening, the flow rate can be adjusted. It was unsuitable for use.

Various proposals for preventing such a rapid change in the flow rate have been made in the past, one example of which is disclosed in Japanese Utility Model Laid-Open Publication No. 2-36667. The ball valve described in the publication is a valve that opens and closes by rotating a closing member having a through hole by approximately 90 degrees,
The cross-sectional shape of the outflow-side opening of the through hole is substantially triangular or elongated rectangular extending in the rotation direction of the closing member.

That is, by making the cross-sectional shape substantially triangular, it is possible to adjust the flow rate by changing the flow rate in a quadratic manner in accordance with the opening degree of the valve, and to make the cross-sectional shape substantially rectangular. By doing so, the flow rate can be adjusted by changing the flow rate linearly in accordance with the opening degree of the valve.

[0005]

However, in the above-mentioned ball valve, it is necessary to prepare two closing members for adjusting the flow rate in case the transport state of the fluid cannot be predicted or in the case of a change in the transport state, which leads to an initial cost and management. This has led to an increase in expenses. Further, when replacing the closing member as needed, it is necessary to disassemble the valve, and there has been a problem that the transportation of the fluid is stopped or the fluid is scattered.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object the two flow characteristics required for flow control, that is, the relationship between the opening degree of the valve and the flow is almost linearly proportional. It is an object of the present invention to provide a ball valve in which the same ratio characteristics as those obtained by one ball valve element can be obtained.

[0007]

The structure of the present invention for solving the above-mentioned problems will be described with reference to FIGS.

The ball valve according to the present invention is a ball valve which opens and closes a valve by rotating a ball valve body 3 having a through hole 5 therein by engaging with the spindle 4 by rotating the spindle 4. One opening 5 of the through hole 5
a (indicated by a dotted line) is circular, the other opening 5b is substantially sector-shaped in cross section in the rotation direction of the ball valve body 3, and the diameter of the circular opening 5a and the sector-shaped opening 5b When the length of the sector opening is D, the length of the short side of the sector is L, the inclination angle of the oblique side of the sector with respect to the rotation direction is θ, and 0.1D ≦ L ≦ 0.3D 10 degrees ≦ The cross-sectional shape is formed so that the relationship of θ ≦ 25 degrees is satisfied at the same time, and the ball valve element 3 is mounted so as to be rotatable 90 degrees in the right and left directions from the closed state. It is.

The sectional shape of the fan-shaped opening 5b of the ball valve element 3 must be formed so as to satisfy the above two conditions at the same time. At the same time, it cannot be obtained with high accuracy.

A more preferable range of the above two conditions is 0.1.
15D ≦ L ≦ 0.25D, 10 degrees ≦ θ ≦ 20 degrees,
By forming them in these ranges, the two flow characteristics can be obtained with higher accuracy.

The material of the ball valve of the present invention may be plastic or metal, and is not particularly limited. The direction of the inflow and outflow of the fluid is not limited, and the fluid may be introduced from either side of the ball valve.
There is no difference in its adjustment function.

[0012]

The operation of the present invention having the above configuration will be described with reference to a ball valve shown in FIG. 1 (valve closed state).
Ball valve element 3 moves rightward through spindle 4 (arrow A)
The fan-shaped opening 5b can be rotated from the short side by 90 degrees to the left and 90 degrees to the left (arrow B).
The flow rate can also be increased from the long side. When the ball valve element 3 is rotated 90 degrees to the right (in the direction A) from the state shown in FIG. 1, the fan-shaped opening 5b opens from the short side, and an equal ratio characteristic is obtained. ), The sector opening opens from the long side, and a linear proportional characteristic is obtained.

When the fan-shaped opening 5b is formed in the opposite direction to the rotation direction, the relationship between the rotation direction and the characteristics is opposite to that described above.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the drawings showing the embodiments, but it goes without saying that the present invention is not limited to the embodiments.

FIG. 1 is a longitudinal sectional view showing an embodiment of the ball valve of the present invention in a closed state (the ball valve body 3 is shown in a front view).

In FIG. 1, reference numeral 1 denotes a substantially hollow cylindrical valve body, and a hollow cylindrical union 2 is screwed into openings at both ends. Reference numeral 6 denotes a body cap connected to a pipe or the like (not shown). The body cap 6 is detachably fixed to both ends of the valve body 1 via the union 2 by cap nuts 7 screwed to outer circumferences of both ends of the valve body 1. ing. In the valve body 1, a ball valve element 3 which engages with a spindle 4 and has a through hole 5 therein is sandwiched by a seat ring 8 mounted on the union 2, and is rotated rightward (A direction) by the spindle 4. And 90 in the left direction (B direction)
It is provided rotatable by degrees.

When the ball valve element 3 is turned to the right, the through-hole 5 has a circular opening 5a on the outlet flow path 10 side.
The cross-sectional shape of the opening 5b on the inlet flow path 9 side is substantially sector-shaped in the rotation direction of the ball valve body 3, and the diameter of the circular opening 5a and the length D of the sector-shaped opening 5b are the same. Is formed. When the ball valve element 3 is turned to the left, the above positional relationship is reversed.

In this embodiment, the sectional shape of the fan-shaped opening 5b is provided such that L = 0.22D and θ = 13.5 degrees. (See Fig. 2)

The operation of the ball valve according to the present embodiment having the above configuration will be described with reference to FIG. In the figure, since the inlet flow path 9 and the outlet flow path 10 are closed by the ball valve element 3, the flow of the fluid flowing from the inlet flow path 9 is stopped, and the valve is completely closed. Here, when the ball valve element 3 is rotated rightward (A direction) via the spindle 4 by an automatic control device or manual operation, the fan-shaped opening 5
Since b is opened from the short side, the flow rate can be increased and adjusted almost equally to the valve opening. When it is further turned, it turns 90 degrees and becomes a fully open state. (FIG. 3
reference)

On the other hand, when the ball valve body 3 is rotated leftward (arrow B) from the closed state, the fan-shaped opening 5b opens from the long side, so that the flow rate is substantially linearly proportional to the valve opening. Can be increased and adjusted. When it is further turned, it turns 90 degrees and becomes a fully open state.

With the above operation, two kinds of flow rates can be adjusted with one ball valve element. In other words, it is not necessary to prepare two types of closing members in case the state of transport of the fluid cannot be predicted or for the change of the state of transport, and the two kinds of flow rate adjustments merely change the rotation angle of the ball valve body. It can be easily selected, and complicated work such as disassembling the ball valve and replacing the closing member is not required.

Here, a bore 80 having the structure shown in FIG.
An actual flow test was performed using a ball valve with A and D = 68.5 mm, L = 15 mm, and θ = 13.5 degrees under the following conditions.
In addition, those having a cross-sectional shape deviating from the above-mentioned condition range (diameter 80A, D = 68.5 mm, L = 0 mm, θ = 10 degrees) were simultaneously performed. [Conditions] Fluid: Water Fluid temperature: 25 ° C Pressure difference across the valve: 0.5 kgf / cm ²

[0023]

[Table 1]

The results are shown in FIG. 4 and Table 1. FIG.
In FIG. 7, the opening degree is 90% to the right from the closed state (0%), and the opening degree is 100%, and the rotation to the left is 90 degrees, and the opening degree is -100%. Curve A
1 and A2 represent the products of this example, and B1 and B2 represent those whose cross-sectional shapes are out of the above-mentioned range.

Table 1 shows the opening degrees 30 to 100 in FIG.
% (-30 to -100%) (dotted line) (a
1, b1, a2, b2)) (%)
(Corresponding to C1, D1, C2, D2).

As can be seen from FIG. 4 and Table 1, in the product of the present embodiment, 9
By rotating by 0 °, the maximum error is reduced to + 11% in the case of the equal ratio characteristic and −5.5% in the case of the linear proportional characteristic, and both characteristics are obtained with high accuracy.

On the other hand, when the maximum error is out of the above condition range, the maximum error is as large as + 19.5% in the case of the proportional characteristic, and as large as + 24% in the case of the linear proportional characteristic, and sufficient performance is not obtained.

[0028]

The following effects can be obtained by using the ball valve of the present invention described above. Two flow characteristics required for flow control, that is, a linear proportional characteristic and a proportional characteristic in which the relationship between the valve opening and the flow rate is obtained by one ball valve body. Therefore, when the transport state of the fluid cannot be predicted, or when two or more types of closing members are not prepared in preparation for a change in the transport state, initial costs and maintenance costs can be reduced. The two types of flow rate adjustment can be easily obtained only by changing the rotation direction of the ball valve body. As a result, the transportation of fluids has stopped,
Work such as disassembly of a ball valve for replacing the closing member is omitted, and work efficiency is greatly improved. Since there is no need to replace the closing member, there is no problem such as splashing of a chemical solution, and the safety of workers is ensured, and environmental pollution can be prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view including a partial front view showing an embodiment of a ball valve of the present invention.

FIG. 2 is a front view of the ball valve body in FIG. 1 on the side of a fan-shaped opening.

FIG. 3 is a longitudinal sectional view showing a fully opened state of the ball valve in FIG. 1;

FIG. 4 is a flow rate characteristic chart showing results of an actual flow test.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Ball valve main body 2 ... Union 3 ... Ball valve body 4 ... Spindle 5 ... Through-hole 5a ... Circular opening 5b ... Sector-shaped opening 6 ... Body cap 7 ... Cap nut 8 ... Seat ring 9 ... Inlet flow path 10 ... Outlet Channel

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-38767 (JP, A) JP-A-49-16918 (JP, A) JP-A-62-177373 (JP, A) 126674 (JP, U) Japanese Utility Model 2-36667 (JP, U) Japanese Utility Model 63-201265 (JP, U) Japanese Utility Model Utility Model 62-155270 (JP, U) Japanese Utility Model 4-62969 (JP, U) J-Publication 3-29656 (JP, Y2) (58) Field surveyed (Int. Cl. ⁷ , DB name) F16K 5/00-5/22

Claims (1)

(57) [Claims] 1. A ball valve which engages with a spindle and rotates a ball valve body having a through hole therein by rotating the spindle to open and close the valve. The other opening has a circular cross-section in the direction of rotation of the ball valve element, and the diameter of the circular opening is equal to the length of the fan-shaped opening. Length: D Length of the short side of the sector: L When the inclination angle of the oblique side of the sector with respect to the rotation direction is θ: 0.1D ≦ L ≦ 0.3D 10 degrees ≦ θ ≦ 25 degrees. A ball valve having a cross-sectional shape, wherein the ball valve body is mounted so as to be rotatable by 90 degrees in the right and left directions from the closed state.