JPH027339Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a throttle control gate valve that is placed in the middle of a water distribution pipe and adjusts the flow rate and pressure of water, and particularly relates to a throttle control gate valve that allows fine adjustment of the flow rate.

Normally, in water distribution pipe networks, the flow rate is often adjusted by narrowing the opening of the gate valve in response to changes in water demand. The seat a has the same circular shape as the valve body b, and the ratio of the opening cross section c, that is, the cross-sectional area of the flowing water, to the degree of opening is very high. For example, when a gate valve is opened by only 25% of its stroke, the flow cross-sectional area reaches approximately 30%. For this reason, (although this varies depending on the water pressure difference between upstream and downstream of the valve), substantial fluctuations in flow rate only occur when the gate valve reaches its final 10% opening toward closing, making it extremely difficult to control the flow rate. There was a problem with inefficiency.

In addition, when opening and closing a gate valve, at the beginning and end of closing, the cross-sectional area of the flowing water changes greatly due to the change in opening degree as described above, and the flow velocity changes greatly, causing a sudden pressure rise or fall, causing rotation. If the operation is not performed extremely slowly, so-called shock pressure (water hammer) will occur.
There were problems such as the risk of

The present invention was developed in view of the above-mentioned conventional problems and in order to solve these problems. The reinforcement is also large,
The purpose is to provide a gate valve for throttle adjustment that allows smooth opening and closing of the valve body, and is characterized by a gate valve in which the valve body is disposed in a direction perpendicular to the flow path of the valve body. A substantially V-shaped valve seat is provided in a plane direction perpendicular to the axis of the valve, and the valve body is configured to come into sliding contact with the substantially V-shaped valve seat.

Hereinafter, the present invention will be explained in detail based on the illustrated embodiments.

In Figures 2 and 3, 1 is the valve body;
2 is a valve stem disposed within the valve body 1, and 3 is a valve stem 2.
The valve body 4 is threadedly connected to the lower end and formed in a substantially circular shape, and 4 is a substantially V-shaped valve seat on the outflow side. It is attached to a portion forming the passage P in a plane direction perpendicular to the axis of the passage P, that is, in a direction parallel to the valve body 3.
Further, the valve body 3 is arranged to be movable up and down in a direction orthogonal to the flow path P of the valve body 1.

The lower part of the valve stem 2 has a male threaded portion 5 at a predetermined interval.
The valve body 3 has a female screw piece 6 fixed to the upper end of the valve body 3, and is screwed into the female screw piece 6.

Reference numeral 7 denotes a valve box cap, into which a shaft sealing packing 8 is fitted, and a bearing 9 is mounted above it. Reference numeral 10 denotes a valve stem support disposed within the valve box cap 7, and the upper portion of the valve stem 2 passes through the valve stem support 10 and is located further above the shaft seal packing 8 and bearing 9. It stands out.

The valve stem 2 is supported by the valve stem support 10 by the collar 11, and the pin 11 is pressed against the inner surface of the valve box cap 7, so that it cannot move up and down. It is rotatably held by the valve box cap 7.

Further, reference numeral 12 denotes a cap that is attached to the upper end of the valve stem 2 by a pin 13, and the cap 12
A handle (not shown) is fitted into the upper protrusion of the valve and rotated in a predetermined direction, thereby rotating the valve stem 2 together.

In addition, 14 is a valve seat with a valve body fixed to the inflow side of the valve body 1 forming a flow path, 15 is a valve seat with a valve body on the inflow side that makes sliding contact with the valve seat 14 with the valve body, 16
is a valve seat with a valve body on the outflow side that slides into contact with the substantially V-shaped valve seat 4 on the outflow side.

FIG. 4 shows a substantially V-shaped valve seat 4 on the outflow side, which is a feature of the present invention, and its sliding side wall 17 is opened in a substantially V-shape. Specifically, the water passage opening 20 of the valve seat 4 includes a substantially V-shaped opening 18 corresponding to the middle or lower part of the flow path P in the vertical direction, and a substantially semicircular opening 21 corresponding to the upper portion of the flow path P. , is formed by.
The radius of curvature of the approximately semicircular opening 21 is set to be approximately the same as the radius of curvature of the cross-sectional shape of the flow path P in order to reduce the fluid passage resistance in the water passage opening 20 when it is fully opened.

The operation of the throttle control gate valve constructed as described above will be described below.

First, the handle is fitted into the upper protrusion of the cap 12, and when rotated in one direction, the valve stem 2 rotates together. Due to the rotation of the valve stem 2, its male threaded portion 5
The female screw piece 6 screwed into the valve body 6 rises, and the valve body 3 also has its valve seats 15 and 16 on the outflow side and the valve seat with the valve body on the inflow side. 14
It slides into contact with and rises.

This opening state is shown in Fig. 5, and as shown in the figure,
As the valve body 3 rises, the substantially V-shaped opening 18 of the substantially V-shaped valve seat 4 on the outflow side gradually opens larger.

At this time, the flow rate of water is, for example, if θ is 80°,
As shown in Fig. 6, when the opening degree of the valve body 3 is 10%, the water flow cross-sectional area is approximately 2% (13% in the conventional gate valve shown in Fig. 1).
When the opening degree of the valve body 3 is 25%, it is approximately 8% (approximately 30% for the conventional gate valve shown in Fig. 1), and the rate of change in the cross-sectional area of the flowing water in the part where the valve body 3 is open less than that of the conventional gate valve is It will be slower in comparison.

The opening degree and opening cross-sectional area ratio of the throttle control gate valve of the present invention and the conventional gate valve are shown in the graph of FIG. In the graph curve, S indicates the conventional gate valve, and t indicates the throttle control gate valve of the present invention. The opening degree is the opening degree l/L of the valve body in Figures 1 and 5, and the opening cross-sectional area is the opening area when the valve seat is fully opened and the opening area when the valve seat is open. It shows the ratio, ie, e/E.

As clearly shown in this graph, it can be seen that the opening of the valve seat due to the rise of the valve body is much more gradual in the throttle adjustment gate valve of the present invention.

Note that the size of the θ angle of the approximately V-shaped opening 18 may be changed, or the left and right inclined sides 19, 1 forming the approximately V-shaped opening 18 may be changed as shown in FIGS. 7, 8, and 9.
By forming 9 into a curved shape, the characteristic of the rate of change in the opening area of the valve seat relative to the opening degree of the valve body can be selected depending on the application.

It is also possible to attach an opening gauge to the valve, and by visually adjusting the opening gauge, you can see the opening at a glance.
It is very convenient to operate and does not cause any mistakes.

Moreover, since most of the valve body 3 rises while constantly sliding against the opening peripheral wall of the substantially V-shaped valve seat 4, the strength of the valve body 3 is greatly reinforced, and durability is good, and the valve body 3 can be opened and closed smoothly. It has the effect that can be achieved.

As described above, the present invention is arranged such that the valve body 3 is movable up and down in a direction perpendicular to the substantially circular flow path P of the valve body 1, and approximately in a surface direction perpendicular to the axis of the flow path P. It is a gate valve for throttle adjustment configured by disposing a V-shaped valve seat 4, and the water passage opening 20 of the substantially V-shaped valve seat 4 is arranged in a substantially V-shaped valve corresponding to the vertically middle or lower part of the flow path P. The valve body 3 is formed by a mold opening 18 and a substantially semicircular opening 21 corresponding to the upper part of the flow path P, and the valve body 3 is formed in a substantially circular shape. Since the radius of curvature and the radius of curvature of the cross-sectional shape of the flow path P are set to be approximately the same, as the valve body 3 opens, the approximately V-shaped valve seat 4
Since the valve opens gradually, the rate of change in the cross-sectional area of the water flowing in areas where the degree of opening is small (when the valve begins to open) is slower than before, making it easier to finely adjust the water flow rate when the valve begins to open. It is particularly effective when used to suppress the flow rate and reduce the pressure, and also prevents so-called water hammer because pressure fluctuations at the beginning of opening and at the end of closing can be alleviated. When the flow path P is closed by the valve body 3, that is, when the valve body 3 is at the lowest position, the center of the valve body 3 coincides with the axis of the flow path P, so the lower end of the valve body 3 The vertical position of the lower end of the substantially V-shaped opening 18 can be made to match. Therefore, the valve body 1 has a compact shape without protruding downward. A substantially semicircular opening 21 of the water passage opening 20 of the substantially V-shaped valve seat 4 is arranged at the upper part of the flow path P, and the radius of curvature of the cross section of the flow path P is similar to that of the substantially semicircular opening 21. Since the dimensions are set to be approximately the same, the fluid passage resistance when the valve is fully opened can be reduced.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the open state of the valve body and valve seat of a conventional gate valve, and FIG. 2 is a longitudinal cross-sectional view of an embodiment of the present invention.
Fig. 3 is a partially cutaway side view, Fig. 4 is an approximate V
Fig. 5 is an explanatory diagram of the opening state of the valve body and the approximately V-shaped valve seat, and Fig. 6 shows the opening degree of the valve body in the conventional gate valve and the throttle adjustment gate valve of the present invention. Diagrams showing the opening cross-sectional area ratio of the valve seat, Figures 7, 8, and 9
The figure is a front view showing another embodiment of the substantially V-shaped valve seat of the present invention. 1... Valve body, 3... Valve body, 4... Approximately V-shaped valve seat.

Claims (1)

[Scope of utility model registration request] The valve body 3 is arranged to be movable up and down in a direction perpendicular to the substantially circular flow path P of the valve body 1, and the flow path P
A gate valve for throttle adjustment is constructed by arranging a substantially V-shaped valve seat 4 in a plane direction perpendicular to the axis of the substantially V-shaped valve seat 4.
The water passage opening 20 of the molded valve seat 4 is formed into a substantially V-shaped opening 18 corresponding to the middle or lower part in the vertical direction of the flow path P, and a substantially semicircular opening 21 corresponding to the upper part of the flow path P.
The valve body 3 is formed into a substantially circular shape, and the radius of curvature of the substantially semicircular opening 21 and the radius of curvature of the cross-sectional shape of the flow path P are set to be substantially the same. A gate valve for regulating an orifice.