JPS5853287B2 - resistance valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resistance valve used to extract differential pressures in a flow path for sensing a flow path.

In recent years, pumps used in wells, etc., have either significantly smaller pressure tanks or so-called tankless pumps, which omit the pressure tank and automate the drive of the pump in the same way as pumps with pressure tanks. Although tankless pumps are being developed, in order to operate automatically, it is necessary to control the flow rate so that the switch does not open and close frequently, even if the amount of water used is small.

As one of the control methods, a resistance valve is installed at an appropriate position in the flow path, and the differential pressure between the resistance valve and the upstream and downstream sides changes depending on the flow rate l, and when the flow rate is less than a very small fixed amount, There are some devices that take advantage of the fact that the differential pressure disappears, extract the differential pressure, detect the flow rate, and control the opening and closing action of the switch.

Conventionally, the resistance valve used in the above case is equipped with a coil spring 7E so that the valve body 2 faces in the flow direction as shown in FIG.
The coil spring 1 is pressed by a trowel and is configured to apply resistance to the fluid by the pressing force of the coil spring 7 and generate a differential pressure. , δ is the deflection due to the change in flow rate), so when the flow rate increases and the deflection δ increases, the coil spring 7E
The applied load F increases proportionally, and the resistance given to the fluid increases.

Normally, the strength of the coil spring 7 is set so that a differential pressure is generated even when the flow rate is small, so the larger the flow rate, the greater the resistance, which impedes the fluid flow and causes a large disadvantage in resistance loss. .

Furthermore, by making the coil spring longer, the rate of increase in resistance can be reduced to some extent, but it still increases, and there are problems such as the structure of the resistance valve becomes larger, making it difficult to manufacture and increasing the cost.

Furthermore, setting the strength of the coil spring in order to reduce the resistance when the flow rate is large is not practical because the desired differential pressure cannot be obtained when the flow rate is small.

Therefore, with conventional resistance valves, it is unavoidable that the resistance increases at high flow rates, and pump efficiency also decreases at high flow rates due to resistance loss, as shown in the flow rate-head characteristic curve diagram in Figure 2. There was a drawback that the value decreased as much as possible.

In addition, the coil spring E tends to get caught in dirt, which may impede its function as a resistance valve.

The present invention has been devised to eliminate the above-mentioned drawbacks, and to provide a small resistance during large flow rates and a large resistance during low flow rates to obtain the desired differential pressure. It uses suction.

Examples thereof will be described below with reference to the drawings.

In FIG. 3, reference numeral 11 denotes a horizontal flow path connected to a pump or the like, which is expanded at a suitable location.

Reference numeral 12 denotes a valve body supported by swinging freely from the upper part of the channel wall 14 near the upstream flow channel 11 in the expanded portion 13, and swings around the support point 15 depending on the flow rate to close the channel 11. It is provided so that it can be opened and closed, and constitutes a swing valve 10. In particular, when the valve body 12 is fully opened, most of the valve body 12 fits into the expanded portion 13, thereby reducing the resistance given to the fluid. The diameter of the flow path is made larger than the diameter of the flow path 11 to prevent it from swinging in the opposite direction when the flow path is closed.

The valve body 12 has at least a lower end portion, which is a free end 17, made of a magnetic material.

The lower part of the road wall 14 facing the support point 15, that is, the position facing the free end 17 when the swing valve 10 is closed, or the vicinity thereof, is provided with a valve body when the valve body 12 approaches the closed state. A magnet 16 that can magnetically attract the fluid is embedded therein, and when the flow rate is small, the attraction force of the magnet 16 provides resistance to the fluid.

The specific gravity of the valve body 12 is made larger than 1 so that when the flow rate changes from a large flow rate to a small flow rate, the valve body 12 can automatically swing in the closing direction using the action of gravity.

Roughly speaking, when the swing valve 10 is in the closed state, the valve body 1
2 and the road wall 14 provided with the magnet 16, there is a gap 1 through which a flow rate of a certain amount, which is as small as water leakage, can pass through, so that no differential pressure occurs when the flow rate is less than a certain amount, which is very small. Keep it.

A slit may be formed in the valve body 12 instead of the gap l, but if the valve body 12 is adhered to the road wall 14 due to the magnetic force of the magnet 16, it will be difficult to separate, so the minimum gap should be made as described above. It is desirable to have one.

In the above embodiment, the valve body 12 is suspended and supported from the upper part of the road wall 14 as the swing valve 10, but as shown in FIG. It can also be supported by being pivotally supported on the wall 14 so that it can swing freely, and in this case, it is also possible to carry out the method shown in FIG. 5 even in the upward flow path 11.

Furthermore, the present invention can be implemented in the same manner whether the valve body 12 is ball-shaped as shown in FIG. 3 or plate-shaped as shown in FIGS. 5, 6.

Further, when the flow path 11 is formed in a small diameter upstream portion 11a and a large diameter downstream portion 11b as shown in FIG. 6, the swing valve 10 can be provided at the inlet of the downstream portion 11b.

Note that, contrary to the above embodiments, the present invention uses a magnet 16.
It is also possible to implement this by providing a magnetic material on the road wall at least at the free end 17 of the valve body 12 of the swing valve 10.

The present invention is constructed as described above, and when the flow rate is either zero or less than a certain amount such as water leakage, the valve body 12 of the swing valve 10 is in a closed state and is magnetically attracted by the magnet 16.

At this time, no differential pressure is generated between the upstream side and the downstream side of the valve body 12.

When the flow rate increases, the valve body 12 is pushed by the fluid and swings downstream, gradually opening the flow path 11, but the valve body 12 is moved in the closing direction by the magnetic attraction action of the magnet 16. Because it is pulled by the valve body 1
2 resists the flow of the fluid due to the attraction force of the magnet 16, and can provide a large resistance to the fluid.
The desired differential pressure can be obtained.

When the flow rate increases further, the valve body 12 swings open further, but until the magnetic force of the magnet 16 reaches the range, that is, until the valve body 12 is no longer pulled by the magnetic attraction action of the magnet 16, the attraction force It can provide resistance to the fluid, and as the suction force decreases, the resistance gradually decreases.

When the flow rate increases and the valve body 12 is no longer magnetically attracted by the magnet 16, no resistance is generated due to the attraction force of the magnet 16, and only a slight resistance is generated due to the gravitational action of the valve body 12.

Furthermore, since the resistance valve of the present invention is a swing valve in which the valve body 12 opens and closes by swinging, the surface that receives resistance pressure against the fluid is inclined so as to be almost parallel to the flow direction as it swings in the valve opening direction. First, since the valve body 12 escapes from the central flow area, the larger the flow rate, the less it obstructs the fluid flow, and the less resistance it provides to the fluid.

Furthermore, the structure is simple and there is no risk of dirt getting caught like with coil springs.

Therefore, in the present invention, there is almost no resistance and the resistance loss of the fluid is extremely small when the flow rate is large, but when the flow rate is small, a large resistance can be generated by the magnetic attraction action of the magnet, and the desired difference can be reliably achieved. It can obtain pressure, and can exhibit extremely excellent effects especially when detecting the flow rate by extracting the differential pressure at a small flow rate.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a conventional resistance valve, Fig. 2 is a flow rate-head characteristic curve diagram of a pump when using a conventional resistance valve,
FIG. 3 is a sectional view showing an embodiment of the present invention, and FIG. 4 is a cross-sectional view showing an embodiment of the present invention.
5 and 6 are cross-sectional views taken along line V-IV, respectively, showing different embodiments. 10...-swing valve, 11... flow path,
12...Valve body, 13...Expansion part, 1
4... Road wall, 16... Magnet, 1
7...Free end, l...Gap.

Claims (1)

[Claims] 1. A swing valve 10 is provided in the flow path 11, and a magnet 16 is attached to at least one of the free end 17 of the swing valve 10 and a position facing the free end 17 when the swing valve 10 is closed, and a magnet 16 is attached to the other. A resistance valve characterized in that a magnetic material is provided to provide resistance to the attraction force of the magnet 16 to the fluid when the flow rate is small. 2. The resistance valve according to claim 1, wherein the valve body 12 of the swing valve 10 is suspended and supported from the upper part of the passage wall 14 in the lateral flow path 11. 3. A resistor according to claim 1 or 2, which has a gap l between the free end 17 and the road wall 14 when the swing valve is closed.