JPH023243B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a flow switch for detecting a small flow rate;
In particular, it relates to a composite type flow switch with a check valve function.

[Technical background of the invention and its problems]

In a water supply system that supplies water sent from a water supply pump to a predetermined location, a flow switch is used to detect the flow rate in the water supply pipe and accurately control the amount of water supplied. . As such a flow switch, one that can accurately detect even a small amount of water flow and start or stop the pump has been developed (for example, Japanese Patent Application Laid-Open No. 1989-1999).
Publication No. 65803).

By the way, in a normal water supply system, consideration must be taken to prevent water hammer that occurs when the pump stops during a power outage and water backflows.

However, in the above-mentioned conventional flow switch, the small flapper is swingably suspended in a rectangular notch formed in the lower part of the first flapper, so when water backflow occurs, teeth,
The small flap swings toward the inlet side of the flow switch, causing water to flow backwards through the flow switch, causing water hammer.

Therefore, when using the above conventional flow switch, it was necessary to provide a check valve for preventing water hammer on the outflow port side (downstream side) of the flow switch.

In this way, arranging the flow switch and the check valve separately and independently reduces the piping space and causes an increase in costs.

[Purpose of the invention]

The present invention has been made with these points in mind, and it is an object of the present invention to provide a flow switch having the function of a check valve.

[Summary of the invention]

The flow switch according to the present invention has a small inlet formed in a large flap that is swingably installed vertically in a hollow casing that is open at both ends, and the small flap that closes the small inlet is swung on the downstream side of the large flap. The large flapper and the small flapper are each spring-biased toward the inlet, and a detection switch is placed close to the small flapper to detect the swinging movement of the small flapper. It is a feature.

According to the present invention, a small flow rate can be reliably detected by the rocking motion of the small flapper, and a control signal for the water supply system can be obtained, and when the pump is stopped, the large flapper and the small flapper quickly close the inlet, It is possible to prevent backflow in the pipe line and effectively prevent water hammer.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 are a front sectional view and a sectional view taken along the line of FIG. 1 of a flow switch according to the present invention. In the figure, reference numeral 11 indicates inlet ports 12 at both ends.
and an outlet 13, and inside this hollow casing 11 there is an inlet 1.
A flow path 14 is formed that communicates the outlet port 13 with the outlet port 13 . A valve seat 15 formed by protruding a part of the inner wall of the casing 11 is provided in the flow passage 14, and a large flap 16 is vertically provided so as to come into contact with the valve seat 15. The large flap 16 is formed of a web-shaped plate, and has a size that allows it to come in close contact with the valve seat 15 and completely block the flow path 14. A swing shaft 17 is disposed above the valve seat 15 with both ends rotatably supported by the casing 11, and the upper part of the large flapper 16 is inserted and held in a swingable manner with respect to the swing shaft 17. has been done. A part of the swing shaft 17 has an outlet 1 of the large flapper 16.
A spring 18 is wound around the side 16a facing 3 (downstream side). This spring 18 acts to bias the large flapper 16 toward the valve seat 15. Swing axis 17
Also, there are inlet ports 12 at both ends of the large flapper 16.
The upper ends of a pair of levers 19 that abut from the sides are fitted, and a handle 20 for rotating the swing shaft 17 is fitted on one end of the casing 11 that projects outside.

A small inlet 2 with a small diameter is located at the lower part of the large flapper 16.
A small valve seat 22 is formed at the end of the small inlet 21 facing the outlet 13. A small flapper 23 that is in close contact with the small valve seat 22 and closes the small inlet 21 is swingably installed vertically on the downstream side 16a of the large flapper 16. The upper part of the small flapper 23 is rotatably inserted into and held by a swing pin 24 fixed on the downstream side 16a of the large flapper 16, and the spring 25 wound around the swing pin 24 It is urged toward the small valve seat 22 by one end. A magnet 26 is attached to the lower end of the small flap 23, and a detection switch, such as a reed switch 27, which is operated by the swinging motion of the magnet 26, is disposed below the small flap 23. code 28
is a switch case in which the reed switch 27 is housed.

Next, the operation of this embodiment having such a configuration will be explained.

First, during normal operation, water is forced into the inlet 12 by the water supply pump, and when it enters the casing 11, the pressure energy of the water causes the small flap 23 to
is pressed and swings by an angle according to the flow rate. This swinging motion of the small flapper 23 causes the magnet 26 to actuate the reed switch 27, and the fact that water is being fed through the water supply system and its flow rate are detected. When the amount of water supply increases further, a large flattening occurs.
6 also swings according to the flow rate. If the swinging motion of the large flapper 16 is detected by operating a reed switch or visually, as in the method disclosed in JP-A-54-65803, the flow rate in the water supply system can be completely detected. It is also possible to control multiple pumps. for example,
When the demand for water is high and the large flapper 16 is swinging, multiple pumps are operated at the same time, and when the demand for water is low and the large flapper 16 is no longer swinging, one pump is operated. It is possible to perform operation control such that only one pump is operated and the remaining pumps are stopped, and when the small flapper 23 stops swinging, all pumps are stopped. As a result, the operating time of the pump can be reduced, the durability of the pump can be improved, and running costs can be reduced.

Next, when the pump stops due to a power outage, etc., the large flapper 16 and the small flapper 23
However, due to the urging force of springs 18 and 25,
Perform a rapid closing action to completely block the flow path before backflow occurs in the line. This rapid closing action effectively prevents water hammer. Further, the reed switch 27 is actuated by the swinging of the small flapper 23, and a pump stop signal is generated, and the pump brake is actuated to prevent the pump from reversing.

〔Effect of the invention〕

As explained above, according to the present invention, a small flow rate in a water supply system can be easily and accurately detected by the swinging motion of the small flapper, and if a flow rate detection mechanism is attached to the large flapper, It has excellent effects as a water supply system control device, such as being able to control the operation of multiple pumps. Furthermore, when the pump is stopped, the inlet is quickly closed, preventing backflow in the supply line and effectively preventing water hammer. In addition, the reed switch is activated by the swing of the small flapper.
The pump brake can also be activated, preventing damage to the pump and piping equipment.
Moreover, the functions of such a flow switch and check valve can be performed by one device, and there is no need to arrange them separately as in the conventional case. Therefore, the piping space does not become narrow, and costs can be reduced. Furthermore, since the number of members in the pipe is reduced, pressure loss can be reduced. In addition, the large flapper is swung by a handle 20 attached to the end of the swiveling shaft,
You can check the operation of the reed switch 27, and if the large flap is caught on something and becomes inoperable, you can check the situation with the handle 20 and lever 19, even if it is a minor condition. For example, the caught state can be released using the flapper weight and spring force.

In this embodiment, a horizontal type flow switch has been described, but it can also be used as a vertical type by adjusting the biasing force of the spring. The detected flow rate is determined by the size of the inlet, the strength of the spring, the weight of the flapper, the position of the detection switch, etc., and can be freely adjusted as desired.

FIGS. 3 and 4 are diagrams showing examples of small flaps used to provide the flow switch according to the present invention with the function of a slow-closing check valve. In this example, a small flap 31 vertically installed on a large flap
A dash pot mechanism 33 is attached to a swing pin 32 that swingably holds the small flapper 31 so that the closing operation is performed slowly. That is, as shown in FIG. 4, a fluid-filled space 34 is formed between the swing pin 32 and the upper part 31a of the small flapper 31 inserted and held therein, and the inner wall of the small flapper upper part 31a and the space 34 are filled with fluid. Brake pieces 35 and 36 projecting into the space 34 are arranged and fixed at predetermined intervals on the swing pin 32, respectively.

Therefore, such a dart pot mechanism 3
If the small flapper 31 installed in No. 3 is used, when the flow in the pipe line stops, such as when the pump is stopped, the small flapper 31 will be gently moved by the brake pieces 35, 36 and the fluid resistance in the space 34. It swings to close the small inlet provided through the large flap.

In this way, the small flapper 31 can be used as a slow-closing check valve, and water hammer can be effectively prevented. Since anti-closing check valves have relatively small pressure changes, they are particularly effective when used in water supply systems with large flow rates.

In addition, the small flap 23 for the quick-close check valve mentioned above
If the small flapper 31 for the slow-closing check valve can be replaced with the same large flapper,
It is possible to use different flow switches depending on the application, and it is also possible to reduce manufacturing costs.

[Brief explanation of drawings]

Fig. 1 is a front sectional view of the flow switch according to the present invention, Fig. 2 is a sectional view taken along the line of Fig. 1, Fig. 3 is a view showing a small flapper for a slow-closing check valve, and Fig. 4 is a sectional view of a flow switch according to the present invention.
FIG. 3 is a sectional view showing a dart pot mechanism used in the small flapper shown in the figure. 11...Casing, 12...Inflow port, 13...
...Outflow port, 14...Flow passage, 15...Valve seat, 16
...Big Fratupa, 18...Spring, 21...
Small inlet, 22...Small valve seat, 23...Small flap, 25...Spring, 27...Reed switch.

Claims (1)

[Scope of Claims] 1. A hollow casing comprising an inlet, an outlet, and a flow path that communicates the inlet and the outlet and has a valve seat formed in the middle; a large flapper that is swingably installed vertically so as to contact and close the valve seat; a spring that biases the large flapper toward the valve seat; a spring that is provided through the large flapper and that controls the flow of the casing; a small inlet in which a small valve seat having a continuous peripheral edge is formed at the end facing the outlet; a small valve of the small inlet on the side of the large flap facing the outlet of the casing; a small flapper that is swingably installed vertically so as to abut and close the seat; a small spring that biases the small flapper toward the small valve seat; a small flapper that is disposed close to the small flapper; A flow switch comprising: a detection switch for detecting rocking motion; 2. The flow switch according to claim 1, wherein the small flapper is vertically disposed below the large flapper.