JPS6149539B2 - - Google Patents

Description

Detailed Description of the Invention "Industrial Application Field" The present invention relates to a valve device installed in a fluid transport pipe, and more specifically, the upstream fluid pressure (hereinafter referred to as primary pressure) of the valve device. The present invention relates to a valve device that controls the flow rate of a fluid to a predetermined flow rate value regardless of changes in downstream fluid pressure (hereinafter referred to as secondary pressure) or downstream fluid pressure (hereinafter referred to as secondary pressure).

"Prior Art" First, an example of the structure of such a valve device, which is conventionally considered to be the most common, is shown in FIG. 1 and explained as follows.
A hollow piston-shaped throttle valve operating member 3 fitted in a cylindrical valve box is provided with an orifice- or nozzle-shaped reference flow path 5 at its center, and the pressure difference before and after the reference flow path 5 is When changes,
Since the balance between the thrust force that the member 3 receives from the flow and the force of the spring changes, this throttle valve operating member is displaced, and the throttle valve 4 is operated accordingly to adjust the flow rate (reference flow path 5) to keep the flow rate at a constant value, and the operating force of the throttle valve operating member 3 at this time is nothing but the differential pressure generated by the fluid resistance of the member 3. This is accompanied by a pressure loss, and this pressure loss is actually quite large, and can be a decisive drawback for some water supply equipment.

Figure 2 shows the relationship between the difference between the primary pressure and the secondary pressure, that is, the differential pressure P and the flow rate Q, as a (P-Q) characteristic curve diagram for the constant flow valve shown in Figure 1. In the figure, Q ₁ is a constant flow value, and at that time, the pressure difference between the front and rear of the orifice 5 is P ₁ , and the throttle passage 9 is fully open, so it is assumed that there is no throttle loss at that point. .

And the (P-Q) curve is the origin (P=0, Q=
0) to the upper right, A(P ₁ ,
It reaches point Q ₁ ), then becomes a line almost parallel to the horizontal axis and reaches point B (P ₂ , Q ₂ ≈Q ₁ ). Note that (P ₂ − P ₁ )
can be seen as a pressure drop in the throttle passage 9.

Here, the differential pressure P ₁ means the pressure drop due to the fluid resistance of the throttle valve operating member 3 when the flow rate is Q _1. That is, when the differential pressure is less than P ₁ , the flow rate becomes a constant flow rate Q ₁ . This indicates that the target is not reached. In other words, this indicates that in order for the valve to function as a constant flow valve with a constant flow value Q ₁ , a loss pressure of at least P ₁ is required, and this differential pressure P ₁ is called the minimum differential pressure and is used to judge performance. This is one of the requirements above.

However, conventionally, this type of constant flow valve generally has 1
It is installed and used at the branch point of a large number of pipelines, such as injection nozzles and sprinklers, which have relatively high secondary pressure, and the working pressure P ₂ is usually large, and this minimum differential pressure
P ₁ was also smaller than P ₂ and did not pose much of a problem.

``Problems to be solved by the present invention'' In recent years, the issue of effective water resource utilization has become increasingly important, and in fields such as agricultural water and industrial water, there has been a great deal of momentum in streamlining water distribution and planning equipment. With the progress of scale and consolidation, water distribution pipes have become longer and more complex in lower areas, and it has become necessary to install a large number of variable constant flow valves at each important point. Considering the importance of variable constant flow valves, the technical requirements placed on them are actually quite strict, and these can be listed as follows: 1. Place of installation (e.g. narrow underground bit); Maintenance,
The structure must be simple and compact for safety and other reasons. The structure must be as simple or simpler than conventional constant flow valves.

2.The structure must be such that the constant flow rate value can be changed and set accurately and easily.

3. The minimum differential pressure _P1 , which was explained in detail earlier, must be configured to be as low as possible.

Therefore, when the conventional constant flow valve shown in FIG. 1 is examined in terms of the above-mentioned requirements, it is clear that problems exist with respect to the requirements of items 2 and 3. That is, the first
In the constant flow valve shown in the figure, the constant flow value can be changed by changing the cross-sectional area of the reference flow path 5 (by moving the tip of the rod-shaped member 10 in and out of the flow path 5). It is also well known that the mechanism is complicated because the throttle valve operating member 3 is provided with variable pressure, and that there are problems with accuracy and practicality. Furthermore, considering the principle of operation, the lowest differential pressure
As I have explained in detail, P ₁ cannot be made very small (therefore, there is a problem with requirement 3 above).

Next, as a conventional constant flow valve device, unlike the above-mentioned constant flow valve (orifice type), there is also a structure in which the minimum differential pressure _P1 can be made as low as the one of the present invention.

For example, the "automatic flow rate adjustment device" described in Japanese Patent Publication No. 35-14986 and Publication Utility Model Publication No. 39-29225
It can be seen in

This device has a well-known basic configuration as a flow rate adjustment means using a ventilate tube. A part of the main flow pipe is made into a ventilate tube shape, and the differential pressure in the tube is applied to the upper and lower sides of the diaphragm box. It is easy to see that it is an exaggerated structure that is difficult to put into practical use in the technical field referred to in this application.

Apart from this, in the present invention, the reference flow path, which is an essential component, is configured to be variable, and this point has an important and unique technical meaning in terms of structure and operation effect. Therefore, its technical philosophy is different from the above-mentioned "automatic flow rate adjustment device."

As stated above, the present invention aims to create a variable constant flow valve device that has a structure and performance that can readily meet new technical demands in the future water technology field, and is more suitable for universal use. By adopting the configuration described below, all the problems in conventional variable constant flow valve devices are solved.

B. Structure of the Invention ``Means for Solving Problems'' [1] A throttle valve member for controlling the flow rate to a predetermined value and a throttle valve operating mechanism linked thereto are similar to the constant flow valve illustrated in FIG. Compact and simple structure that can be stored compactly within the valve box.

[2] As mentioned above, in the conventional constant flow valve, the operating force of the throttle valve operating member is mainly due to the fluid resistance acting on the member, but the present invention provides a throttle valve operating member installed in the valve box. Applying different static pressures to two corresponding surfaces of the member at different positions of a variably configured flow path within the valve box,
The configuration is such that the resultant force is used as the operating force.

The basic configuration of the present invention has been described above in accordance with the principle, and an embodiment of this configuration is shown in FIG. 3 and will be explained below.

FIG. 3 shows the center line of the lift valve member spindle in an embodiment of the structure in which the flow passage constructed in the valve device of the present invention is constructed between the valve member of the lift valve device and the inner wall surface of the valve box. A vertical cross-section screen is shown in a plane containing . Reference numeral 11 is a valve box having a substantially bowl-like shape, and reference numeral 12 is an introduction pipe forming an inflow opening flow path a leading to the valve box inlet b. Reference numeral 13 denotes a displaceable flow path constituting member, which extends into the valve seat 14 provided at the entrance to the valve box 11 and is screwed into a screw hole 17 provided at the center of a boss portion 16 provided on the valve box lid 15. Threaded part 1
It is held and fixed on a spindle 19 having a diameter of 8. Therefore, when the spindle 19 is turned from the outside, the member 13 moves up and down perpendicularly to the upper surface, that is, the closing surface, of the valve seat 14, and its lower surface is displaced while maintaining parallel to the upper surface of the valve seat 14, thereby increasing the distance between them. This is similar to a normal lift valve in that when the pressure is changed and both sides are crimped, the reference flow path c is closed and the closed state is established.

FIG. 3 shows a state in which the cross-sectional area of this reference flow path c is maximized. A nose cone 20 is formed in the center of the lower surface of the member 13 so that the flow from the inlet b can be easily diverted to the side (perpendicular to the axis). The flow path forming member 13 (hereinafter abbreviated as member 13 for the sake of explanation) has a substantially cylindrical portion 21 concentric with the center line of the spindle 19 at its outer peripheral portion, and the outer surface of the cylindrical portion 21 and the valve box Flow paths c, d, and e whose cross-sectional area smoothly expands between the inner wall surface of 11 and the inner wall surface are formed. A flow path c is formed inside the upper part 22 of the valve box 11.
A partition wall portion 23 is formed at the end portion of the wall portion 23, protruding toward the center, and having a circular hole concentric with the spindle 19 to form a flow path f. And the partition wall part 2
A throttle valve passage g having a width approximately equal to the maximum lift of the member 13 is provided above the valve box 11 over the entire circumference of the valve box 11, and a passageway for allowing the flow flowing upward through the flow passage f to flow out to the side. Nasu. Note that the outflow flow from the throttle valve passage g is collected in a collecting passage h formed on the outer periphery of the throttle valve passage g, and is directed toward the discharge opening 36 in the pipe line 2.
It flows out from the discharge opening channel i formed in 4. 2
Reference numeral 4 denotes a cylindrical hole concentric with the spindle 19 formed inside the valve box from above the throttle passage g to the upper end surface of the valve body 11, the length of which is greater than the width of the throttle passage g, and the diameter of which is larger than the partition wall portion 23. Almost equal to that of the hole provided in the center. A cylindrical throttle valve member 25 having approximately the same length as the axial length of the hole 24 is fitted tightly and slidably into the hole 24 . Therefore, when the throttle valve member 25 is slid in the axial direction within the hole 24, the passage area of the throttle passage q changes, giving a throttling effect to the flow. Reference numeral 28 is a flower pot-shaped throttle valve operating member whose outer shape is approximately a trapezoidal rotating body, and its bottom portion 26 is connected to the cylindrical portion 21 of the member 13.
A hole 27 is formed concentrically with the spindle 19.
The upper part 29 has a hole 30 in the center of the spindle 19.
It is tightly and slidably fitted and held in the holder. Thus, the throttle valve operating member 28 has its inner and outer surfaces separated, and obtains its operating force by applying different pressures to each surface. Note that 31 is a connecting member between the throttle valve operating member 28 and the throttle valve member 25. Reference numeral 32 denotes a bag chamber composed of the member 13 and the throttle valve operating member 28, and in this embodiment, the chamber 32
A communicating passage 33 is provided to communicate with the reference passage c, which is the part of the passage within the valve box that has the narrowest passage cross-sectional area. Reference numeral 34 denotes a coil spring, one end of which is supported on the lower surface side of the throttle valve operating member 28, and the other end is supported and interposed on the upper surface of the lift valve member 13, which is a member that fixes it to the valve box. It is provided with elasticity that balances the downward force acting on the throttle valve operating member 28 in the flow state.

"Operation" Now, the structural diagram shown in FIG. 3 shows the passage state when the primary and secondary pressure difference is approximately the minimum pressure difference and the flow rate is at the maximum constant flow state. At this time, the throttle valve passage g is fully open, and the lowest differential pressure therebetween corresponds to the pressure loss of the entire flow passage. At this time, as the primary pressure increases, the flow velocity in the flow path increases accordingly, and the difference in static pressure between flow paths with different cross-sectional areas changes (increases), so the force acting on the throttle valve operating member also increases. When the flow rate changes (increases), the throttle valve member 25 is pushed down and provides a throttle effect to suppress an increase in flow velocity and maintain approximately a predetermined flow rate value.

Figure 4 shows the characteristic curve of the conventional constant flow valve shown in Figure ₁ , and the characteristic curve (P'-Q '), and the differential pressure P
Expand the axis scale and find the lowest differential pressure point A (P ₁ ,
_Q1 ) Indicates the situation in the vicinity. I have already stated that the lowest differential pressure P ₁ in a conventional constant flow valve is both a pressure loss and an operating pressure. However, in the present invention, the lowest differential pressure _P'1 is not directly related to the operating pressure and simply represents the flow loss in the flow path, and therefore it is clearly demonstrated that it can be made sufficiently low.

Next, as stated in the Objects of the Invention section, another important object of the present invention is to provide the present constant flow valve device with a wide range of constant flow values in the construction itself, which is optionally and easily. The purpose is to provide a satisfactory structure that can be reliably changed.

That is, the basic structure of the present invention is that the flow paths having different static pressures in the flow path configured in the valve box are configured by members belonging to the fixed joint, so the structural feature is that the flow paths have different static pressures. In a portion (reference flow path) that can be selected at an appropriate location, a simple means can be taken to change the reference flow path by easily changing the constituent members of the flow path from the outside, regardless of the operating parts such as the throttle valve operating member. At the point.

To explain this in detail based on the embodiment shown in FIG.
When the flow path constituting member 13 is pushed down, the flow path c is narrowed, and if the throttle valve operating member 28 does not move at this time, there will be no change in the throttle passage area and the flow velocity will increase. Since the applied differential pressure also changes, the throttle valve member 25 is operated and the flow velocity in the reference flow path c is restored to the predetermined flow velocity.
The constant flow value has therefore been reduced. Even if the differential pressure P' is changed in this state, the flow rate is controlled to this predetermined value by performing the same operation as previously explained for the maximum constant flow state. By further pushing down the member 13 in the same way,
The constant flow value can be varied steplessly up to zero or cut-off.

"Example" In carrying out the present invention, in accordance with the gist of the present invention,
Although various structural changes can be made, FIG. 5 shows an embodiment of the structure in which a flow path is configured to flow through a throttle valve operating member. Incidentally, in this second embodiment, if the primary pressure is so low that it would be disadvantageous to increase the flow velocity in the pipe in order to obtain a pressure difference that acts on the throttle valve operating member, the flow path in the valve box is temporarily It will also be explained that it is even possible to construct a flow path in which the flow velocity is decelerated and then returned to the in-pipe flow velocity in the reference flow path.

FIG. 5 is a longitudinal sectional view of this second embodiment,
Reference numeral 51 indicates a valve box, and reference numeral 52 indicates an inlet introduction pipe. Bento box 51
Inside, an inlet opening flow path k is formed from below, and a flow path is formed on the outside of a flow dividing member 55 fixed to the center of the bulging flow path portion 53 by a rib 54. The upper end of the flow dividing member 55 forms a plane perpendicular to the axis, and its shape is approximately equal to the diameter of the flow path k. A cylindrical hole 5 whose diameter is approximately equal to the diameter of the flow path k formed in the upper edge of the flow dividing member 55 and the valve box 51 on the downstream side thereof.
8, and a cylindrical throttle valve member 59 is tightly and slidably fitted into the cylindrical hole 58. and the throttle valve member 59
A flange-shaped throttle valve operating member 61 is integrally formed on the upper end portion 60 perpendicular to the center line of the member 59, and an outer circumferential portion 62 of the member 61 is provided on a portion 64 extending in the outer circumferential direction at the upper part of the valve box. cylindrical hole 72
It is tightly and slidably fitted to the Reference numeral 65 denotes a compression coil spring, whose lower end is supported by a step 63 within the valve box 51, and whose upper end is placed against the lower surface of the throttle valve operating member 61. The upper end surface of the valve box is sealed with a valve box lid 66 whose center part is shaped like an upside-down bowl, and a screw hole 67 provided in the center boss of the lid 66 is screwed into a screw hole 67. A flow path forming member 68 is attached to the spindle 69 that is passed through the held spindle 69 . The flow path forming member 68 is formed in a downward concave shape,
The lower surface of the outer periphery forms an annular surface 71 in a plane perpendicular to the axis, and faces the upper end surface of the cylindrical hole 72, forming a reference flow path s therebetween. Therefore, when the spindle 69 is rotated, it can be displaced in the axial direction and the reference flow path s can be changed. Note that t is a collection flow path for discharge flows from the flow path s, and u is an outlet flow path. Reference numeral 73 denotes a bag chamber formed by the flow path forming members 61 and 65, and the chamber 73, ie, the lower surface side of the throttle valve operating member, is communicated with the reference flow path s through a communication path 74.

In the above configuration, the fluid introduced from the inlet channel k flows through the channels m and n, which have the same cross-sectional area, and turns laterally in the wide channel q, becoming a decelerated flow and static pressure. , then enters the reduced flow path r, increases the flow velocity there, restores to the initial flow velocity in the pipe, and flows out from the reference flow path s. This valve device has the above-mentioned structure, and the mode of its operation can be easily understood from the detailed explanation given above, so a detailed explanation will be omitted. Note that 75 indicates a drift prevention member provided on the lower inner surface of the flow path forming member 68 variably fixed to the valve box, and indicates a conventional means such as a suitable guide vane, metal thread, or a flexible protruding piece. shall be.

D. Effects of the Invention As described above in detail with respect to its configuration and its effects, the present invention has a configuration that can theoretically reduce the minimum differential pressure to an infinitely low level, and therefore a simple and compact throttle valve operating mechanism is compactly housed inside the valve box. It is easy to see that the storage structure is reliable and its operation is highly reliable. Moreover, since it is applicable to a wide range of primary and secondary pressure differences, it is a variable constant flow valve device that is extremely versatile both from the perspective of use and from the perspective of production. It fully satisfies the requirements and is suitable not only for fields where conventional constant flow valves are used, but also for fields where conventional constant flow valves are used.
It can also be used in fields where it cannot be used due to its drawbacks and in the above-mentioned water technology fields where strict performance is required, and its unique effects are remarkable.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a conventional constant flow valve device, Figure 2 is a vertical sectional view of a conventional constant flow valve device;
The figure is a characteristic diagram showing the relationship between the primary and secondary pressure difference and the flow rate in a conventional constant flow valve device, and FIG. 3 is a longitudinal sectional view of an embodiment of the variable constant flow valve device according to the present invention.
Fig. 4 is a comparison diagram on a characteristic diagram between a conventional constant flow valve device and a constant flow valve device according to the present invention, and Fig. 5 is a vertical cross section of another embodiment of the variable constant flow valve device according to the present invention. It is a front view. 11, 51... Valve box, 15, 66... Valve box lid,
a, k...Inlet opening channel, i, u... Outlet opening channel, 13, 68... Channel forming member (equipped with displacement means), c, s... Reference channel, 19, 69... ... Spindle, 27, 72 ... Hole made concentric with the variable shaft, 28, 61 ... Throttle valve operating member, d, e,
q, r...Flow path whose cross-sectional area is smoothly changed, g, m... Throttle passage, 25, 59... Throttle valve member, 33, 74... Communication path, 34, 65... Spring, 32,73...bag room.

Claims (1)

[Claims] 1 A flow path forming member 13, 68 that is close to one of the two open flow paths provided in the valve box, is fixed to the valve box portion, and is movable at any time.
, and valve seat-like members 14 and 64 fixed to the valve box portion, which correspond to the flow path forming members 13 and 68, constitute variable reference flow paths C and S, and from the reference flow paths C and S, Channels d, e, q, and r whose cross-sectional areas smoothly change toward the other openings i and u are formed, and throttle valve members 25,
59 are provided, and throttle valve operating members 28, 61 connected to the throttle valve members 25, 59 are fitted into the bag chambers 32, 73 formed in the flow path constituent members, The throttle valve operating member 28, 6
The two isolated pressure-receiving surfaces of 1 are provided with means for applying static pressure of flow channels having different cross-sectional areas, that is, communication passages 33 and 74, and furthermore, the throttle valve operating members 28 and 61 are arranged in a predetermined manner. The throttle valve operating member 2 has an elastic spring that balances the force received from the fluid in the flow state.
8, 61 and a variable constant flow valve device interposed between the member fixed to the valve box.