JPH07286873A - Flow rate detector - Google Patents

Abstract

PURPOSE:To obtain an inexpensive flow rate detector which can be easily and directly set in a pipeline by fitting magnets to the swinging end sections of flappers fitted to a frame in a swingable state and sensing the contact and separation of the magnets with and from reed switches from the outside of the pipeline. CONSTITUTION:A flapper 11a for small flow rate and another flapper 11b for large flow rate are fitted to a shaft 13 in a swingable state and cylindrical hollow magnets 18a and 18b are firmly fixed to the swinging end sections of the flappers 11a and 11b. When a water pump is operated and a prescribed small amount of fluid starts to flow through a pipeline 30, the flapper 11a first swings against the force of a spring 14a and the small flow rate is detected by sensing the separation of the magnet 18a from a reed switch 19a which is a sensing means. When the flow rate of the fluid in the pipeline 30 increases, the flapper 11b swings against the force of another spring 14b and a prescribed large flow rate is detected by sensing the separation of the magnet 18b from another reed switch 19b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow rate detecting device for detecting a predetermined flow rate of a fluid in a pipeline, and more particularly to a flow rate detecting device which can be easily installed in an existing pipeline.

[0002]

2. Description of the Related Art In a water supply system for supplying water supplied from a water supply pump or the like to a predetermined location, a flow rate detecting device for detecting a predetermined flow rate is used in a pipeline.

Generally, such a flow rate detecting device is provided with a casing connected via a flange between pipe lines and a flapper mounted in the casing so that the flapper can swing freely. Based on this, the predetermined flow rate is detected.

[0004]

In the above-mentioned flow rate detecting device, it is necessary to arrange the pipe line in accordance with the flow rate detecting device. That is, pipes to which flanges corresponding to the respective flanges on the inflow side and the outflow side of the casing of the flow rate detecting device are attached are provided on the inflow side and the outflow side of the casing, and the flow rate detecting device is connected via these flanges. It is connected to the pipeline.

For this reason, the work of mounting the pipeline and the flow rate detecting device becomes complicated. Further, if the flow rate detecting device is to be attached later to the portion where the pipeline is already arranged, it becomes necessary to partially or completely replace the pipeline. Further, there is a problem that the manufacturing cost of the casing of the flow rate detecting device is high.

The present invention has been made in view of the above points, and provides a flow rate detecting device which can be directly and easily mounted in an existing pipeline and which can reduce the manufacturing cost. The purpose is to

[0007]

SUMMARY OF THE INVENTION The present invention relates to a flow rate detecting device which is inserted into a conduit through which a fluid flows, and a frame mounted in the conduit and a flapper swingably mounted on the frame. A magnet attached to the swinging end of the flapper, a means arranged outside the pipe for sensing contact and separation of the magnet, and a fixing means for fixing the frame in the pipe. It is characterized by having.

[0008]

According to the present invention, when the flow rate detecting device is mounted in the pipeline, the frame having the flapper is inserted in the pipeline, and the frame is fixed by the fixing means in the pipeline. be able to.

When the fluid flows into the pipe line to which the flow rate detecting device according to the present invention is attached, the flapper oscillates, and the magnet attached to the oscillating end of the flapper is arranged outside the pipe line. The sensing means senses that the fluid has separated from the sensing means, and a predetermined flow rate of the fluid is detected.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 4 are views showing an embodiment of a flow rate detecting device according to the present invention.

In FIG. 1 and FIG. 2, the flow rate detecting device is provided on the frame 10 inserted into a pipe 30 through which a fluid flows, and outside the pipe 30 across the diameter of the pipe 30. And a bracket 15.

The frame 10 has a ring shape, and a pipe 30
Has an outer diameter slightly smaller than the inner diameter of. A shaft 13 is attached to a surface of the frame 10 on the downstream side in the fluid flow direction (direction of arrow L in FIG. 2) orthogonal to the fluid flow direction. When viewed from the front of the frame 10 (see FIG. 1), the shaft 13 is attached while being displaced downward by a certain distance from the center.

The shaft 13 has a large flapper 11a.
And a flapper 11b having a smaller shape than the flapper 11a is swingably attached. Each of these flappers 1
1a and 11b are shaped so as to cover substantially the whole above and below the shaft 13 in the cross section of the conduit 30 when closed.

The flappers 11a and 11b are pressed against the frame 10 in the closing direction by springs 14a and 14b attached to the shaft 13, respectively. The flappers 11a and 11b are closed until the fluid flows at the respective predetermined flow rates, and when the fluid flows further, the springs 14a and 11b are closed.
It is designed to open against the force of a and 14b. Hollow cylindrical magnets 18a and 18b are fixed to the swinging end portions of the flappers 11a and 11b, respectively.

The predetermined flow rate at which each flapper 11a, 11b is opened is determined by the elastic force of each spring 14a, 14b and the point of its force, the shape of each flapper 11a, 11b, and each flapper 11a including each magnet 18a, 18b. 11b
It can be changed according to the weight and the position of the center of gravity.
In the present embodiment, the predetermined flow rate at which the large shape flapper 11a opens is set to be smaller than the small shape flapper 11b, the large shape flapper 11a is used for the small flow rate flapper, and the small shape flapper 11b is used for the large flow rate flapper. I am trying.

On the other hand, as shown in FIG. 1, the bracket 15
Has a shape of a substantially octagonal half when viewed from the front, and both ends 15a and 15b are arranged so as to face each other across the diameter of the conduit 30. Further, a pair of ribs denoted by reference numeral 16 is provided on the outer side of the bracket 15, and the bracket 15 is reinforced so that the space between both end portions 15a and 15b does not spread.

Set screws 20 are respectively screwed into both ends 15a and 15b of the bracket 15 so as to face each other in the diameter direction of the conduit 30. Further, the set screw 20 is also screwed into the central portion of the bracket 15 so as to face the center of the conduit 30. Further, a lock nut 24 for fixing each set screw 20 to the bracket 15 is screwed onto the thread portion 21 of each set screw 20.

Next, the set screw 20 will be described in detail with reference to FIG. As shown in FIG. 3, a pin-shaped tip portion 22 concentric with the thread portion 21 projects from the tip surface 21 a of the thread portion 21 of the set screw 20, and a recess 21 is formed around the base end of the tip portion 22.
b is formed in a ring shape. And in this recess 21b,
A seal member 23 such as an O-ring is fitted.

On the other hand, as shown in FIG. 2, in the pipe line 30 and the frame 10, three holes 32 and 12 penetrating in the radial direction of the pipe line 30 are formed in correspondence with the tips 22 of the set screws 20.
The distal end portion 22 penetrates the hole 32 of the conduit 30 and enters the hole 12 of the frame 10 at each of the positions.

Further, both ends 15a, 1 of the bracket 15 are
5b is provided with a mounting plate 26, which is fitted into the set screw 20 and fixed by a lock nut 24. On the mounting plate 26, the respective sensing means 19a, 19b such as a reed switch, and the respective magnets 18a, 18 are provided.
It is attached so as to be located near the surface of the conduit 30 corresponding to b.

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

First, the mounting operation of the flow rate detecting device will be described. From the pipeline connection opening such as a flange portion near the flow rate detection device mounting position of the pipeline 30 in which the hole 32 is provided in advance,
The frame 10 to which the flappers 11a and 11b are attached is inserted into the conduit 30. The frame 10 inserted into the conduit 30 is moved to the flow rate detection device mounting position using a jig or the like, and each hole 12 of the frame 10 is replaced with each hole 32 of the conduit 30.
Are aligned to correspond to.

Next, the set screw 20, the lock nut 24, and the sensing means 19a, 19b, etc. are temporarily fixed to the bracket 15, and the bracket 15 is arranged so as to straddle the pipe 30 in the diametrical direction. Set screw 20 tip 22
Are aligned with corresponding holes 32 in line 30. Then, each set screw 20 is screwed into the bracket 15 so that the tip 22 of each set screw 20 penetrates the hole 32 of the conduit 30 and enters the hole 12.

The set screws 20 are completely screwed in to fix the frame 10 and the bracket 15 to the conduit 30, and the sealing member 23 of each set screw 20 is sufficiently crimped to the surface of the conduit 30, and then the lock nut 24 is tightened. To fix each set screw 20 and the mounting plate 26. In this way, the sensing means 19
a, 19b are connected to the magnet 18a,
It is fixed at a position corresponding to 18b.

Next, the flow rate detecting function of the flow rate detecting device will be described.

When the water supply pump (not shown) is stopped and the fluid is not flowing in the pipeline, each flapper 11a, 11b.
Is in the closed position indicated by the solid line in FIGS. When the water supply pump operates and the fluid begins to flow in the direction of the arrow L in FIG. 2 for a predetermined small flow rate (for example, 10 l / min), the small flow rate flapper 11a first resists the force of the spring 14a. It swings in the direction of arrow A in FIG. 2, and the sensing means 19a senses that the magnet 18a is separated from the sensing means 19a, and detects a predetermined small flow rate.

For example, when the sensing means 19a is a reed switch, the separation of the magnet 18a can be sensed by turning off the reed switch and stopping the current flow.

Further, the flow rate of the fluid in the conduit 30 increases,
A predetermined large flow rate (eg, 20 l /
min), the large flow rate flapper 11b swings in the direction of arrow B in FIG. 2 against the force of the spring 14b, and the sensing means 19b senses that the magnet 18b has separated from the sensing means 19b. Detect a predetermined large flow rate.

As described above, according to the present embodiment, the flow rate detecting device can be directly and easily installed in the existing pipeline, and it is necessary to specially dispose the pipeline for mounting the flow rate detecting device. Absent. Further, since it is not necessary to provide a casing for the flow rate detecting device, the manufacturing cost can be reduced.
Further, since the flapper for the small flow rate and the flapper for the large flow rate are provided, it is possible to detect the predetermined flow rate in two steps of large and small with one flow rate detecting device.

Although the example in which the bracket 15 has the rib 16 has been described, the rib 16 is not limited to this, and the bracket 16 may be omitted as long as the bracket 15 has sufficient rigidity and can hold each set screw 20 firmly. Alternatively, the bracket 15 may have another shape such as a semicircle or a U-shape when viewed from the front (direction of FIG. 1). Also, the bracket 1
5. The central set screw 20 and the corresponding pipe line 30 and the holes 12 and 32 of the frame 10 are for more stably fixing the frame 10 and the bracket 15 to the pipe line 30. Can be omitted.

Further, the bracket 1 provided outside the conduit 30
Although the example in which the frame 10 is fixed by 5 is described, the frame 10 may be fixed by sandwiching the frame 10 from the upstream side and the downstream side with a spacer or the like in the conduit 30.

Further, the sensing means 19a and 19b are not limited to the reed switches, and other means may be used as long as they can sense the contact and separation of the magnets 18a and 18b.

[0033]

As described above, according to the present invention, when the flow rate detecting device is installed in the pipeline, the frame having the flapper attached is inserted into the existing pipeline and the frame is fixed by the fixing means. Since the flow rate detecting device can be attached only by fixing it in the pipeline, the mounting work is easy and there is no need to specially dispose the pipeline for mounting the flow rate detecting device. Further, it is not necessary to provide a casing for the flow rate detecting device, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a flow rate detecting device according to the present invention.

FIG. 2 is a side sectional view of the flow rate detection device shown in FIG.

3 is a partial vertical cross-sectional view showing details of a set screw of the flow rate detection device shown in FIG.

[Explanation of symbols]

 10 Frames 11a, 11b Flapper 15 Brackets 18a, 18b Magnets 19a, 19b Sensing means 20 Set screw 22 Tip part 30 Pipeline

Claims (3)

[Claims] 1. A flow rate detecting device which is inserted into a pipe through which a fluid flows, a frame mounted in the pipe, a flapper swingably attached to the frame, and a swing end of the flapper. A magnet attached to the section, means for detecting contact / separation of the magnet disposed outside the pipe, and fixing means for fixing the frame in the pipe. Flow rate detector. 2. The flow rate detecting device according to claim 1, wherein the flapper comprises a large flow rate flapper and a small flow rate flapper. 3. The fixing means comprises a bracket extending outside the conduit in the diametrical direction of the conduit, and a pair of set screws screwed into the bracket so as to face the diametrical direction of the conduit. 3. The flow rate detection device according to claim 1, wherein the pair of setscrews have their tip end portions penetrating a pipe line and engaged with the frame.