JP2584935B2 - Flowmeter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow meter for accurately measuring the amount of combustion air in a gas-fired water heater, for example.

[0002]

2. Description of the Related Art Heretofore, for example, the measurement of the amount of combustion air in a gas water heater or the like has been performed by measuring the number of revolutions of a blower or a fan motor. However, the number of rotations of the fan motor only measures the volumetric flow rate, and accurate measurements cannot be made due to the effects of pressure due to altitude differences and external weather conditions. Supplying.
As a result, or large in size also instrument itself, there is a problem such as generation of NO _X, was also caused a problem of wasting such as energy can not optimum combustion.

Therefore, in order to prevent this problem, as shown in FIG.
The ends of the cylindrical body protruding to the outside of the duct 23 are connected to the through holes 25 of the sensor main body 24 by tubes 26 and 27, and the flow sensor is provided in the through holes 25. A part 28 is provided. Such a flow sensor unit 28
Is designed to be less sensitive to altitude differences and the outside world,
In order to use a thermal flow sensor and to reduce the size of the entire water heater, the flow sensor itself needs to be downsized.
A structure in which a diaphragm 32 having a thickness of 20 μm or less is provided on a 1.7 mm square semiconductor chip 31 as shown in FIG. 3, and a micro flow sensor having a heating resistance pattern and a temperature-sensitive resistance pattern is mounted on the diaphragm. It is.

[0004] With the above configuration, the hole 21 is formed in one of the cylindrical bodies 21.
The air that has flowed in through the tube 26, the through hole 25, and the tube 27 flows out of the hole 22 a of the cylindrical body 22, and the output of the flow rate sensor unit 28 based on the amount of flowing air is supplied to the drive circuit 29, and the combustion is performed. Accurate measurement of the working air volume is performed.

[0005]

Since the conventional flow rate measurement is constructed as described above, the flow rate sensor section 28 is very small, so that the sensitivity is very good and accurate measurement can always be performed. Poor reliability with respect to adhesion and dew condensation of dust of 30 μm, and does not withstand long-term use. In particular, in a kitchen or a kitchen in which a gas water heater is installed, there is a problem that the temperature difference between when it is used and when it is not used is large, dust and the like easily adhere, and dew condensation tends to occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to obtain a flow meter having an excellent effect of collecting dirt, dust and small insects.

[0007]

According to the present invention, the surfaces of the partition plate and the dust collecting plate are provided with fine irregularities such as satin finish, or the surface is coated with an adhesive or a hygroscopic agent.

[0008]

With the above-mentioned fine uneven surface or an adhesive or a hygroscopic agent, dirt and dust can be adhered to the partition plate or the dust collecting plate. The effect is enhanced.

[0009]

【Example】

Embodiment 1 FIG. In FIG. 1, a cylindrical portion 2 of a cylindrical body is provided on a front plate 1 a of a case 1, and a distal end opening of the cylindrical portion 2 is closed by a front surface 3. The cylindrical portion 2 is axially partitioned by a partition plate 4 into two chambers 2a and 2b. Two small holes 5a and 5b are provided near the tip of the cylindrical portion 2,
The small hole 5a communicates the room 2a with the outside air, and the small hole 5b communicates the room 2b with the outside air.

In each of the rooms 2a and 2b, a plurality of dust collecting plates 6 alternately arranged on both sides of the partition plate 4 from both sides.
Is provided. The front plate 1a is provided with a hole 7a communicating with the room 2a and a hole 7b communicating with the room 2b. A flow sensor unit using a hot wire type flow sensor is provided in the case 1.

Further, fine irregularities are formed on the front and back surfaces 4a of the partition plate 4 and the front surface 6a of each of the burnt plates 6. The fine unevenness is, for example, satin. As a method of forming the satin, for example, (1) a method by chemical corrosion. For example, when an ABS resin is used for plastic molding, the surface is treated with chromic acid after molding. (2) A satin is formed in a molding die. (3) By sandblasting. And the like.

As the fine irregularities, a large number of small holes may be provided on the surfaces 4a and 6a. When the flowmeter configured as described above is arranged in the air flow path such that air flows in from the lower small hole 5b, for example, the air flowing from the small hole 5b passes through the room 2b and further flows into the hole 7b.
The flow rate is measured from b through a sensor unit (not shown) in the case 1. The air that has passed through the sensor section flows out of the small hole 5a on the upper side through the room 7a from the hole 7a.

The air that has entered the room 2b through the small holes 5b, when passing between the partition plate 4 and the dust collecting plate 6,
Garbage, small insects, and the like are collected by the unevenness of the surface 4a of the partition plate 4 and the surface 6a of the dust collecting plate 6.

In the above description, air is taken in from the lower hole 2a and air is made to flow out from the upper small hole 5a. Conversely, air is taken in from the upper small hole 5a and May be used to allow air to flow out of the small hole 5b. In that case, dust and dirt in the air entering through the small holes 5a are collected by the dust collecting plate 6 in the room 2a.

Embodiment 2 FIG. Further, an adhesive may be applied to each of the surfaces 4a and 6a. As the pressure-sensitive adhesive, for example, a pressure-sensitive adhesive such as an acrylic pressure-sensitive adhesive that exhibits pressure-sensitive adhesive properties when air is acting thereon is used.

Embodiment 3 FIG. Further, each of the above surfaces 4a, 6a
May be coated with a moisture absorbent. As the hygroscopic agent, for example, non-dry oil such as camellia oil is used.

Embodiment 4 FIG. The above-mentioned fine unevenness, an adhesive, a hygroscopic agent, etc. may be provided on the inner surface of the cylindrical portion 2 as necessary.

[0018]

According to the present invention, fine irregularities, an adhesive, a hygroscopic agent, etc. are provided on the surfaces of the partition plate and the dust collecting plate, so that dirt, dust, small insects, etc. can be adhered. If it adheres, it will not be scattered again by airflow,
The dust collecting effect can be further enhanced. In addition, when the adhesive is provided, dust and the like during storage in a warehouse for a long time after production are surely adsorbed, so that the dust does not fly up after assembly and has no adverse effect. In addition, it goes without saying that the present invention has a high utility value in the air flow, the gas flow, and the like as long as a problem with dust or the like occurs.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a flow meter according to an embodiment of the present invention.

FIG. 2 is a front view of a conventional flow meter.

FIG. 3 is a perspective view of a flow sensor unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 1a Front plate 2 Cylindrical body 2a, 2b Room 4 Partition plate 4a Surface 5a, 5b hole 6 Dust collecting plate 6a Surface 7a, 7b hole 8 Flow rate sensor part

Claims (1)

(57) [Claims] 1. A front plate having a hole provided in a case provided with a flow rate sensor section therein, a pipe section having an interior partitioned into two chambers in an axial direction by a partition plate, and a valve end closed. In a flowmeter provided with a pair of small holes that respectively communicate each room and the outside, and further provided with a dust collecting plate on both sides of the partition plate, fine irregularities are formed on the surfaces of the partition plate and the dust collecting plate. A flow meter, provided or provided with an adhesive or a hygroscopic agent.