JP3509946B2 - Flow sensor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impeller type flow sensor suitable for measuring a minute flow rate.

[0002]

2. Description of the Related Art In order to measure a minute flow rate of a liquid such as water, there is a demand for an inexpensive flow rate sensor which is used by being incorporated in equipment such as a shower toilet, a water purifier or a coffee maker.

As a flow rate sensor used for minute flow rate measurement, an actual measurement type flow meter such as a gear type volume meter driven by an upstream / downstream pressure difference, and an impeller flow meter for rotating an impeller by a water flow of a nozzle. The speculative flow meter is known.

In the impeller type flow meter, a magnet (permanent magnet) is attached to the upper end of the impeller in order to extract the flow rate pulse as an electric signal, and the rotation of this magnet is detected by a magnetic sensor to determine the flow rate pulse. I was taking it out. Mounting position of the magnet, it was higher than the fulcrum is a contact of the pin bot and the impeller position.

As a method for measuring the rotation of the impeller of an impeller type flow meter, a measuring method using light is also known.

[0006]

As a flow rate sensor incorporated in a device such as a shower toilet, a water purifier, or a coffee maker, the actual measurement type flow meter of the above-mentioned prior art is used. Since it has to be as severe as possible, there is a problem that it becomes expensive as a result. There is also a problem in that the movable part is fixed by foreign matter and the fluid does not flow.

In the speculative type flowmeter, the rotational force at the same flow rate is smaller than the rotational force of the actual measurement type flowmeter, so it is necessary to minimize mechanical loss due to friction of the rotating portion.
However, in the impeller-type flow meter, in which the magnet fixed to the upper end (tip) of the impeller is sensed from the surroundings, the center of gravity of the impeller is considerably above the fulcrum, and the balance of the impeller is increased. I couldn't get it.

Therefore, in addition to the frictional force due to its own weight, the frictional force due to the moment is also applied to hinder the smooth rotation of the impeller in the minute flow rate range. This is because in the minute flow rate range, the impeller rotates at a low speed, and as described above, the imbalance of the impeller is unbalanced and a larger frictional force is applied.

For this reason, such an impeller type flow meter has not been put to practical use as a flow rate sensor to be used by incorporating it in equipment such as a shower toilet, a water purifier or a coffee maker.

Further, the impeller type flow meter for detecting the rotation of the impeller has a problem that the detection circuit element is expensive and measurement becomes impossible if the light transmittance is obstructed. This, too, has not been put into practical use as a flow rate sensor to be used by incorporating it in equipment such as a shower toilet, a water purifier or a coffee maker.

In view of the above, the present invention takes advantage of the advantage that the impeller type flow meter in which a magnet is attached to the impeller is lower in cost than the actual measurement type flow meter, and furthermore, the core runout in the minute flow rate range is reduced. Dissolved, impeller type flow sensor that allows the impeller to rotate smoothly, especially shower toilets,
An object of the present invention is to provide an impeller-type flow rate sensor suitable for being used by incorporating it in a device such as a water purifier or a coffee maker.

[0012]

To SUMMARY OF THE INVENTION To achieve the above object, a first aspect of the present invention, attached a magnet to the impeller which is rotatably supported by a pin bot, the movement of the magnet by the magnetic sensor In the impeller type flow sensor for sensing and detecting the rotation of the impeller , the bottom of the main body case (1)
Upright from the upper part, and impeller (6) at its upper end
The pivot (5) that supports the
A hole is formed vertically in the center and is located above the hole.
An impeller (6) on which a pebbles (7) is placed and fixed, and an impeller
Two places in the lower part of (6) that divide the circumference into two, that is, an impeller
On the diameter of and equidistant from the vertical axis
Magnets (11) (11) fixed symmetrically in place
On the lower side of the body case (1) and on the axis of the pivot (5)
On the other hand, the magnets (11) (1
Magnetic sensor (12) (1) that senses the movement of 1)
2) and the magnets (11) (11) and the magnetic sensor
The magnetic attraction force acting between the support (12) and (12) varies.
It is characterized by acting as a sensor .

The invention of claim 2 is characterized in that, in the invention of claim 1, an air chamber (9) is provided in an upper portion of the impeller (6).

[0014]

[Function] The mounting position of the magnets (11) (11) is
Bot (5) by becomes lower position than the support point for supporting the impeller (6), the center of gravity of the impeller is reduced, the rotation is balanced to stabilize. Moreover, a magnetic sensor (12)
Provide (12) at two locations that are axisymmetric with respect to the axis of the pivot
Therefore, the magnet (11) (11) and the magnetic sensor (1
2) The magnetic attractive force acting between (12) and
Acts and is averaged.

[0015] air chamber when the metering liquids, since to reduce the weight of the impeller (6) by buoyancy, Pi bot (5)
Reduce the force applied to.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of FIG. 1, reference numeral 1 is a body case of a flow sensor, which is formed by molding plastic. Two
Inlet fluid (water), 3 outlets, 4 the impeller chamber, 5 is a pin bot was implanted on the bottom of the main body case 1, the main body case 1
It stands vertically from the bottom of the.

[0017] 6 in the impeller, that the center hole is the peak bot 5 in the vertical direction is inserted are formed, jewel 7 is fixedly positioned on top of the hole. Reference numeral 8 is an impeller cap fixed to the upper end of the impeller 6, 9 is an air chamber in which a gas such as air is sealed, and 10 is an upper case, which is airtightly fixed to the main body case 1.

Reference numerals 11 and 11 denote small magnets which are attached to the lower portion of the impeller 6 in a balanced manner. In the embodiment, they are symmetrically provided at two locations on the diameter of the impeller and at an equidistant distance from the vertical axis of the impeller 6 at equal distances, that is, at two locations where the circumference of the impeller is divided into two equal parts. , It is fixed to the impeller by heat staking.

Reference numerals 12 and 12 denote magnetic sensors, which are the main body case 1
Below the, it is provided at two positions axially symmetric relative to the axis of the pin bot 5. The fluid to be measured (water) causes the impeller 6 to rotate by the water flow flowing into the impeller chamber 4 from the nozzle of the inlet 2.
This action is the same as in the case of a so-called tangential flow impeller water meter.

[0020] The center of gravity of the impeller 6, the upper end of the pin bot 5,
That positioned below the point of supporting the impeller 6, the impeller 6, is supported on the pin bot as a so-called balancing toy, it rotates a balance.

[0021] Thus, even in low-speed rotation of the fine flow rate range, the frictional force between the pin Bo Tsu <br/> DOO is constant, there is no possibility to increase as in the prior art. As a result, despite being a speculative formula,
It is possible to measure the flow rate in a minute flow rate range, and it is possible to measure a wide flow rate range from a small flow to a large flow.

When the magnets 11 and 11 are provided at positions close to the vertical axis of the impeller 6, the inertial force of the impeller is reduced and the measurement error is reduced.

[0023]

Since the flow rate sensor of the present invention is configured as described above, it is possible to measure a wide range of flow rate though it is an impeller type inexpensive structure and is a speculative type. Especially, the balance of rotation of the impeller is good in the minute flow range.
Since the impeller rotates stably, the instrumental difference performance is also improved. In addition, the magnetic attraction force between the magnetic sensor and the magnet may vary.
Therefore, there is no deterioration in instrumental error performance due to magnetic attraction.
Yes.

[0024] In the invention of claim 2, in the case of metering liquids, friction fulcrum pin bot decreases, measurement performance is further improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of the present invention.

[Explanation of symbols]

1 the main body case 5 pin bot 6 impeller 7 jewel 9 air chamber 10 upper case 11 magnet 12 magnetic sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 5-87512 (JP, A) JP 60-128371 (JP, A) JP 55-90818 (JP, A) Actual flat 6- 56726 (JP, U) Actual development 4-21916 (JP, U) Actual development Sho 56-117313 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01F 1/075

Claims (2)

(57) [Claims] 1. A mounting a magnet on the impeller which is rotatably supported by a pin bot, the vane wheel flow sensor for detecting the rotation of the impeller by sensing the movement of the magnet by the magnetic sensor, the body case It is erected vertically upward from the bottom of (1).
A pivot (5) for supporting the impeller (6) at the upper end of the and a hole into which the pivot (5) is inserted are formed in the central vertical direction.
And the stone (7) was fixed at the top of the hole.
The impeller (6) and two parts of the circumference of the impeller (6) at the lower part, namely,
On the diameter of the impeller and equidistant from the vertical axis
Magnets (11) (1
1) and the lower side of the body case (1) with respect to the axis of the pivot (5)
The magnets (11) (11) at the two axially symmetric
Magnetic sensor (12) (12) that senses movement
Provided with a magnet (11) (11) and a magnetic sensor (1
2) The magnetic attractive force acting between (12) and
A flow sensor characterized in that it acts as a device . 2. A flow sensor according to claim 1, characterized in that an air chamber (9) is provided in the upper part of the impeller (6).