JPH05288582A - Flow meter - Google Patents

Abstract

PURPOSE:To provide a flow meter by which water staying in a cylinder part can be prevented from infiltrating into a case. CONSTITUTION:In a flow meter, a tip blocked-up cylinder part 2, whose inside is partitioned into two chambers 2a and 2b in the shaft direction, is arranged on a front plate 1a having holes 7a and 7b of a case 1 inside which a flow rate sensor part 8 is arranged, and small holes 5a and 5b are arranged in this cylinder part 2 so as to communicate the respective chambers 2a and 2b and an external part with each other. A water stopping plate 13 having a pair of holes 14a and 14b is fitted on the cylinder part so as to be movable in the orthogonal direction to the shaft direction. Thereby, water can be damed up even if it is used in an upsidedown condition.

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 Conventionally, the amount of combustion air in a gas water heater, for example, has been measured by the number of revolutions of a blower or a fan motor. However, the rotation speed of the fan motor only measures the volumetric flow rate, and since it is not possible to make accurate measurements due to the influence of pressure due to altitude differences and the weather conditions in the external environment, it is normal to have more air than required on the safety side. We are supplying.
As a result, there have been problems such as an increase in the size of the equipment itself and the generation of NO _X , which makes it impossible to perform optimal combustion and wastes energy.

Therefore, in order to prevent this problem, as shown in FIG. 4, two cylindrical bodies 2 are made orthogonal to the air flow direction.
1, 22 are arranged side by side in the duct 23, and the tube end projecting to the outside of the duct 23 and the through hole 25 of the sensor body 24 are connected by the tubes 26 and 27, and the flow sensor is provided in the through hole 25. A section 28 is provided. The flow rate sensor unit 28
Is a thermal type flow sensor in order not to be affected by the altitude difference and the external environment, and the flow sensor itself needs to be downsized in order to downsize the entire water heater.
, A diaphragm 52 having a thickness of 20 μm or less is provided on a 1.7 mm square semiconductor chip 51, and a heating resistance pattern 53 and a temperature-sensitive resistance pattern 5 are provided on the diaphragm 52.
This is a configuration in which a microflow sensor in which 4, 55 are arranged is attached.

With the above construction, the hole 21 is formed in the one cylinder 21.
The air flowing in from a is caused to flow out from the hole 22a of the cylindrical body 22 through the tube 26, the through hole 25, and the tube 27, and the output of the flow rate sensor unit 28 based on the flowing air amount is supplied to the drive circuit 29 to perform combustion. Accurate measurement of the amount of air used is performed.

[0005]

Since the conventional flow rate measurement is constructed as described above, since the semiconductor chip 51 is very small, the sensitivity is very good and the accurate measurement can be always performed, but the It is unreliable to dust of 20 to 30 μm and condensed water, and cannot withstand long-term use. In particular,
In the kitchen or kitchen where the gas water heater is installed, the temperature difference between when the gas water heater is used and when the gas water heater is not used is large, dust and the like are likely to adhere, and dew condensation water may be generated to wet the flow rate sensor unit. Since such a flow rate sensor unit is a heat flow type micro flow rate (micro flow) sensor, when it gets wet with dew condensation water, the resistance value of the heat ray changes significantly, and accurate flow rate measurement cannot be performed. Therefore, it is necessary to avoid such a situation. is there.

The present invention has been made in order to solve the above problems, and a flow meter capable of preventing the infiltration of water accumulated due to dew condensation into a sensor portion with one type of product regardless of the direction of use. Is intended to provide.

[0007]

In the flowmeter according to the present invention, a water stop plate having two holes is inserted from the side of the cylinder, and the water stop plate is placed in a direction orthogonal to the axial direction of the cylinder. By moving it, the position of the hole can be adjusted according to the direction of use.

[0008]

[Function] The water is dammed by the part of the fixed length from each hole of the water stop plate to the bottom of each room, and the position of the above part can be changed by moving the water stop plate according to the direction of use. it can.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In each of the drawings, a front surface 1a of a case 1 is provided with a cylindrical tube portion 2, and the front end opening of the tube portion 2 is closed by a front surface 3. Further, the cylindrical portion 2 is partitioned by a partition plate 4 into two chambers 2a and 2b in the axial direction. Two small holes 5a and 5b are provided in the vicinity of the tip of the tubular 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.

Further, in each of the chambers 2a and 2b, a plurality of dust collecting plates 6 arranged alternately on both sides of the partition plate 4 are 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. In the case 1, the flow rate sensor unit 8 is provided with the holes 7a, 7
It is provided in contact with b.

A notch 4a is provided in a portion of the partition plate 4 which is in contact with the front plate 1a, and the front plate 1 of the cylindrical body 2 is cut.
A pair of upper and lower cuts 2c are provided in a portion in contact with a so as to face the cuts 4a.

On the other hand, a water stop plate 13 having a pair of holes 14a and 14b at the top and bottom is prepared. The water stop plate 13 is inserted into the cuts 2c and 4a, and as shown by arrows a and b, the cylindrical portion 2 is formed. Is movably fitted in a direction orthogonal to the axial direction of.

Next, the operation of the above configuration will be described. FIG. 1 shows a state in which the lower small hole 5b is used as an air intake port, in which the water stop plate 13 is moved in the direction of arrow a. In this state, each hole 14 of the water stop plate 13
The height from the lower end of a, 14b to the bottom of each room 2a, 2b is height h. This height h portion can prevent water (not shown in FIG. 1) accumulated in each room 2a, 2b from flowing toward the holes 7a, 7b of the front plate 1a.

When the water stop plate 13 is moved in the direction of arrow b by a length h in the state of FIG. 1, the length from the upper end of each hole 14a, 14b to the ceiling of each room 2a, 2b becomes h. Therefore, if it is used upside down in this state, the length h
Water can be dammed by this part.

FIG. 3 shows another embodiment of the water stop plate 13, in which holes 14a and 14b are provided with a dust removing filter 15,
It is designed to enhance the dust collection effect.

[0016]

According to the present invention, the water stop plate having the two holes is fitted to the cylinder so as to be movable in the direction orthogonal to the axial direction, so that the cylinder is irrespective of the use direction of the flowmeter. Since it is possible to reliably prevent water that has accumulated inside the body from raindrops or dew condensation from entering the case, it is possible to achieve accurate (air) flow rate measurement using a highly sensitive heat wire type minute flow sensor as a flow meter. Further, it is possible to obtain an effect that it can be used for a long period of time under bad conditions such as a water heater, which is apt to cause dew condensation and dust adhesion.

[Brief description of drawings]

FIG. 1 is a side sectional view of a flow meter according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a disassembled state and the whole of the flow meter.

FIG. 3 is a front view showing another embodiment of the water stop plate used in the flow meter.

FIG. 4 is a front view of a conventional flow meter.

FIG. 5 is a perspective view of a flow rate sensor unit.

[Explanation of symbols]

 1 Case 1a Front Plate 2 Cylinders 2a, 2b Room 5a, 5b Small Holes 7a, 7b Holes 8 Flow Sensor 13 Water Stop Plates 14a, 14b Holes

Claims (1)

[Claims] 1. A cylindrical portion in which a front plate 1a having a pair of holes 7a, 7b of a case in which a flow rate sensor portion 8 is provided is internally partitioned into two chambers 2a, 2b in the axial direction and the tip is closed. In the flowmeter, which is provided with 2 and a pair of small holes 5a, 5b for communicating each room with the outside in this tubular part, a water stop plate having a pair of holes 14a, 14b is attached to the tubular part. A flowmeter characterized by being fitted so as to be movable in a direction orthogonal to the direction.