JP2652675B2 - Ball valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial Application Field) The present invention adjusts a supply amount, that is, a flow rate of a fluid flowing through a valve, with opening and closing of a flow of a fluid such as cold water, hot water, and fuel oil. More particularly, the present invention relates to a ball valve for flow adjustment having a simple structure that adjusts the flow by changing the opening of the valve according to a signal from a controller.

(Prior Art) An ordinary ball valve has a cylindrical through hole at the center of a ball, and the through hole and the diameter of the downstream ball seal overlap to form an opening area, which changes the flow rate. However, there is a defect that the fluid flow rate does not change linearly with the rotation angle of the ball, and the flow rate changes greatly due to a slight change in the rotation angle of the ball. Was unsuitable for However, in recent years, focusing on various characteristics of a ball valve that has a simple structure in which a stem connected to the ball is rotated and the ball is rotated to open and close, and has excellent operability and sealability,
Some attempts have been made to improve this so that it is also suitable for flow control.

The ball valve described in JP-B-46-36786 is one example. In this ball valve, one of the openings of a cylindrical through hole formed in the center of the ball is formed in a V-shape to adjust the flow rate.

Further, a ball valve described in Japanese Patent Application Laid-Open No. 62-177373 and a ball valve described in Japanese Utility Model Application Laid-Open No. 62-183173 have been proposed.

(Problems to be Solved by the Invention) However, in the structure of the ball valve described in Japanese Patent Publication No. 46-36786, it is extremely difficult to machine the through-hole, and the flow rate changes linearly with the rotation angle of the ball. However, as shown in FIG. 6 of the publication, the problem that the flow rate changes remarkably due to a slight change in the rotation angle of the ball has not been improved much.

Further, the ball valve described in JP-A-62-177373 has better flow characteristics than the above-mentioned ball valve,
The angle of rotation from fully open to fully closed is approximately 90 degrees, and strict flow adjustment requires considerable accuracy in the angle of rotation of the ball. Further, drilling from one side and milling cutter processing from the other side are necessary to machine the through hole of the ball. Therefore, in order to adjust the flow rate with this ball valve, there is a problem that a great deal of labor and cost are required for the processing.

Further, in the ball valve described in Japanese Utility Model Application Laid-Open No. 62-183173, the flow characteristics are further improved, but the processing of the slit formed in at least a part of the through hole requires more labor than the above. And costly.

The present invention has been made in view of the above-described drawbacks of the ball valve used for adjusting the flow rate, and requires much labor and cost to process the ball for adjusting the flow rate. It is an object of the present invention to provide a ball valve that solves the problems that the relationship is not linear and the flow rate characteristics are inferior, and the flow rate significantly changes due to a slight change in the rotation angle of the ball.

Configuration of the Invention (Means for Solving the Problems) The present invention is configured as follows in order to solve the above-described problems.

That is, a ball that adjusts the flow rate of fluid flowing from an inlet at one end of a valve body and flowing out from an outlet at the other end of the valve body in substantially proportion to a rotation angle of a ball mounted at a substantially central portion of the valve body. A ball seat mounted on the inlet side of the valve body and supporting the ball in contact with the ball and having a structure in which the space between the valve body and the ball is not sealed, and the ball seat mounted on the outlet side of the valve body. The downstream ball seat that contacts the ball and supports the ball is a structure that seals between the valve body and the ball, and the ball has a groove whose width and depth increase proportionally on the surface of the ball. Along the equator, it was set to a length of more than 90 degrees and less than 270 degrees in longitude.

(Operation) In the ball valve of the present invention, the upstream ball seat is mounted on the inflow side of the valve body and supports the ball in contact with the ball. For example, a notch is formed in the contact surface with the ball. The valve body and the ball are not sealed by providing a groove. Further, the downstream ball seat is mounted on the outlet side of the valve body, supports the ball in contact with the ball, and has a structure for sealing between the valve body and the ball. Always opens into the space between the valve body and the ball, closing the valve,
That is, it is the downstream ball seat that separates the flow path on the inlet side and the flow path on the outlet side in the valve closed state.

Then, on the surface of the ball, in longitude along the equator of the ball
The groove having a relatively large width and depth provided at a length of more than 90 degrees and less than 270 faces the space between the valve body and the ball and the flow path on the inlet side in the closed state. And does not face the flow path on the downstream side. For this reason, the downstream ball seat is separated from the flow path on the inlet side and the flow path on the outlet side.

When the ball is rotated in the valve-opening direction from the valve-closed state, the groove provided on the surface of the ball passes through the downstream-side ball seat and looks into the flow path on the outlet side. The space and the flow path on the outlet side communicate with each other, and the fluid flows from the inlet side to the outlet side. However, in this case, the flow rate is extremely small because the width and depth of the groove viewed into the flow path on the outlet side are small.

Subsequently, when the ball is rotated in the valve opening direction, the width and depth of the groove passing through the downstream ball seat and looking into the flow path on the outlet side are relatively increased, so that the flow rate is relatively increased. Then, when the ball is rotated until the width and depth of the groove looking into the outlet-side channel become maximum, the flow rate becomes maximum.

As described above, in the ball valve of the present invention, the function of adjusting the flow rate is performed by the groove provided on the surface of the ball. In particular, since the groove is provided so that the width and the depth are proportional, the relationship between the rotation angle of the ball and the flow rate is linear.

Also, the length of this groove is 90 in longitude along the equator of the ball.
Since it is more than 270 degrees and less than 270 degrees, as described above, the groove can not only face the space between the valve body and the ball in the open state, but also can face the flow path on the outlet side. Therefore, the rotation angle of the ball from the valve open state to the valve closed state can be set to more than 90 degrees and up to 270 degrees. Therefore, unlike a conventional ball valve in which the ball valve is changed from the closed state to the fully opened state within a rotation angle of 90 degrees, the flow rate does not significantly change due to a slight difference in the rotation angle of the ball.

(Example) Hereinafter, one example of the present invention will be described with reference to the drawings.

FIG. 1 is a partially cutaway perspective view showing one embodiment of the ball valve of the present invention.

In FIG. 1, 1 is a ball valve, 2 is a valve body of the ball valve 1, and the valve body 2 has two parts.
2a and 2b. Reference numeral 3 denotes an inflow port provided at one end of the valve body 2, and 4 denotes an outflow port provided at the other end of the valve body 2. Fluid flows in from the inflow port 3 and flows out from the outflow port 4 as shown by arrows. I do.

In the figure, reference numeral 5 denotes a ball connected to the stem 8, reference numeral 6 denotes an upstream ball seat mounted on the inlet 3 of the valve body 2 to support the ball 5, and reference numeral 7 denotes a ball mounted on the outlet 4 of the valve body 2. A downstream ball seat that contacts the supporting ball 5 and supports the ball 5, and the upstream ball seat 6 is
The downstream ball seat 7 has a structure that seals the space between the valve body 2 and the ball 5 without sealing the space between the ball 5 and the ball 5.

8 is a stem connected to the ball 5,
Usually, it is connected to a driving device (not shown) for rotating the stem in response to a signal from the controller.

FIG. 2 is a view showing the upstream ball seat 6.
(A) is a side view, (b) is a longitudinal sectional view, and a notch groove 6b is provided on a contact surface 6a of the upstream ball seat 6 with the ball 5, and FIG. The flow path on the side of the inlet 3 always communicates with the space 9 between the valve body 2 and the ball 5, and the size of the cutout groove 6 b becomes a size suitable for the maximum flow rate of the ball valve 1. ing.

In order to provide a structure in which the upstream ball seat 6 does not seal the space between the valve body 2 and the ball 5, a method of providing a fluid flow path such as the cutout groove 6b in the upstream ball seat 6 as described above is not necessarily required. Not limited to this, a groove may be provided in the step portion 2c of the valve body 2 where the upstream ball seat 6 is mounted, and a fluid flow path passing outside the upstream ball seat 6 may be provided.

Next, FIG. 3 is a cross-sectional view of the ball 5, (a) is a cross-sectional view, and (b), (c), (d), (e), (f) and (g) are the same (a). 3) is a partial longitudinal sectional view of B, C, D, E, F and G sections.

As can be seen from these figures, along the surface equator of the ball 5, a groove 5c having a relatively large width 5a and depth 5b is provided, and the length 5d of the groove 5c along the equator is represented by longitude. It is slightly shorter than 270 degrees. The length 5d of this groove exceeds 90 degrees
Although it is less than 270 degrees, the longer the length, the smaller the change in the flow rate due to a slight change in the rotation angle. The ball 5 shown in FIG. 3 is in the fully closed state when there is an A section at the center of the outlet 4, and when the ball 5 is rotated counterclockwise, the G section comes to the center of the outlet 4. Fully open, that is, a state of the maximum flow rate.

Next, the operation of the embodiment shown in FIGS. 1 to 3 will be described.

An upstream ball seat 6 is mounted on the inflow port 3 side of the valve body 2 and supports the ball 5 in contact with the ball 5. As described above, a cutout groove 6b is provided in the contact surface 6a with the ball 5, and the space between the valve body 2 and the ball 5 is not sealed. The downstream ball seat 7 is mounted on the outflow port 4 side of the valve body 2, and is in contact with the ball 5.
And a structure that seals the space between the valve body 2 and the ball 5, so that the flow path on the inflow port 3 side always communicates with the space between the valve body 2 and the ball 5. 1 is closed, that is, in order to isolate the flow path on the inlet 3 side and the flow path on the outlet 4 side in the valve closed state,
This is the downstream ball seat 7.

Next, on the surface of the ball 5, a width 5a and a depth 5 provided at a length of more than 90 degrees and less than 270 in longitude along the equator of the ball 5 are described.
The groove 5c, which increases b in proportion, faces the space 9 between the valve body 2 and the ball 5 and the flow path on the inlet 3 side in the valve closed state, and the downstream ball seat 7 and the outlet It does not face the flow path on the fourth side. For this reason, the flow path on the inflow port 3 side and the flow path on the outflow port side 4 are isolated by the downstream ball seat 7.

When the stem 8 is operated from the valve closed state to rotate the ball 5 to the valve open state, a groove 5c formed on the surface of the ball 5 is formed.
Is passed through the downstream ball seat 7 and looks into the flow path on the outflow port 4 side. The space 9 between the valve body 2 and the ball 5 communicates with the flow path on the outflow port 4 side, and the fluid flows. It flows from the inflow port 3 side to the outflow port 4 side. However, since the width 5a and the depth 5b of the groove 5c viewed in the flow path on the outlet 3 side in this case are small, the flow rate is extremely small.

Subsequently, when the ball 5 is rotated in the valve-opening direction, the groove 5c passes through the downstream ball seat 7 and looks into the flow path on the outlet 4 side.
The flow rate increases proportionately because the width 5a and the depth 5b of the hole are relatively increased. When the ball 5 is rotated until the width 5a and the depth 5b of the groove 5c looking into the flow path on the outlet 4 side become maximum, the flow rate becomes maximum.

As described above, in the ball valve 1 of the present embodiment, the function of adjusting the flow rate is performed by the groove 5c provided on the surface of the ball 5, and particularly, the groove 5c is formed so that the width 5a and the depth 5b are proportional. Since it is provided, the relationship between the rotation angle of the ball 5 and the flow rate is linear.

The groove 5c can be machined by rotating the ball 5 with an end mill having a hemispherical tip or a milling cutter having an arc-shaped outer edge, or by using a precision structure (lost wax) or the like. Processing can be performed easily and inexpensively, for example, by forming a shape, and it is not necessary to perform a V-shaped processing of the through hole or a difficult processing such as providing a slit in at least a part of the through hole.

In this embodiment, the groove 5c and the length 5d are only slightly shorter than 270 degrees in longitude along the equator of the ball 5,
In the open state, the groove 5c can face not only the space 9 between the valve body 2 and the ball 5 but also the flow path on the outflow port 4 side. When the rotation angle of the ball 5 exceeds 90 degrees as in the present embodiment,
Can be up to 270 degrees. For this reason, unlike the conventional ball valve in which the valve is changed from the closed state to the fully opened state within the rotation angle of 90 degrees, the flow rate does not significantly change due to a slight difference in the rotation angle of the ball 5.

Effects of the Invention As is clear from the above description, the ball valve of the present invention has the following excellent effects.

(1) Since the groove provided in the ball is formed so that the width and the depth increase proportionally, the relationship between the rotation angle of the ball and the flow rate is linear, and excellent flow rate characteristics can be realized. .

(2) It has a simple structure, and it is easy to form a groove for a ball so as to allow the flow rate to be adjusted.

(3) The rotation angle from the fully opened state to the fully closed state can be up to 270 degrees, and the flow rate does not significantly change due to a slight change in the rotation angle of the ball. Sex is greatly improved.

[Brief description of the drawings]

FIG. 1 is a half sectional view showing an embodiment of the ball valve of the present invention, FIG. 2 is a view showing an upstream ball seat shown in FIG. 1, FIG. 1 (a) is a side view, and FIG. Is a vertical sectional view, the third
FIG. 1 is a cross-sectional view of the ball shown in FIG. 1, in which (a) is a cross-sectional view, and (b), (c), (d), (e), (f) and (g) are the same. FIG. 3 is a partial longitudinal sectional view taken along a line B, C, D, E, F and G in FIG. 1 Ball valve 2 Valve body 3 Inlet 4 Outlet 5 Ball 5a Width 5b Depth 5c Groove 5d Length 6 Upstream Side ball seat 7: Downstream ball seat

Claims (1)

(57) [Claims] The flow rate of a fluid flowing from an inlet at one end of a valve body and flowing out from an outlet at the other end of the valve body is substantially proportional to a rotation angle of a ball mounted at a substantially central portion of the valve body. A ball valve to be adjusted, wherein a ball seat mounted on the inflow side of the valve body and supporting the ball in contact with the ball has a structure that does not seal between the valve body and the ball. The downstream ball seat mounted on and in contact with the ball to support the ball has a structure for sealing between the valve body and the ball, and the ball has a groove whose width and depth increase proportionately on the surface of the ball. A ball valve with a length of more than 90 degrees and less than 270 degrees in longitude along the equator of the ball.