JPH0687822U - Fluidic gas meter with security function - Google Patents

Abstract

(57) [Summary] [Purpose] Simplify the flow path body mold and facilitate secondary processing. It facilitates the assembly of the flow sensor, piezoelectric film sensor, pressure switch and shutoff valve, and facilitates automation of assembly. Also, it prevents fogging of the window glass due to condensation of moisture, short circuit of the electric circuit, and generation of rust. [Structure] A flow sensor (not shown), a piezoelectric film sensor, and a pressure switch 3 and a shutoff valve 4 are attached to the front surface of the flow path body 5. A pressure switch cover 37 is provided between the front case 24 to which the window glass 29 is attached and the pressure switch 3 so as to cover the outside air introduction side of the pressure switch 3. The atmospheric pressure from the vent hole 28A of the front case is the pressure switch cover 3
The diaphragm of the pressure switch 3 is caught through the ventilation hole 37a of the pressure switch 3.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fluidic gas meter having a security function for shutting off gas in an emergency.

[0002]

[Prior art]

 A fluidic gas meter is known that has a security function that displays the amount of gas used, displays abnormal gas flow rate, abnormal gas pressure, and earthquake, and shuts off the gas for safety in an emergency (Actual Kaihei 4 -120330 and Jitsukaihei 4-326015).

These fluidic gas meters include a piezoelectric film sensor for detecting fluid vibration of the fluidic oscillation element and converting it into an electric signal, and the oscillation of the fluidic oscillation element is unstable or does not oscillate. In order to measure the amount of gas used in the minute flow rate range, a flow sensor for detecting the flow velocity is provided on the rear wall surface of the nozzle of the fluidic oscillator.

Since the flow path of the nozzle portion is narrowed and the flow velocity increases, a so-called thermal flow sensor is arranged in this portion, and the flow velocity is detected to measure the gas usage amount in the minute flow rate region. This is particularly described in detail in the above-mentioned Japanese Laid-Open Patent Publication No. 4-326015.

As a configuration for fulfilling the security function, a flow sensor for detecting the amount of gas used, a piezoelectric film sensor, a pressure switch, a vibration sensor, a shutoff valve (solenoid valve), an electronic circuit having a microcomputer, and Batteries were used.

As described in Japanese Utility Model Laid-Open No. 4-326015, a flow sensor and a piezoelectric film sensor are mounted on the rear surface of a die-cast flow path body forming a fluidic oscillation element, and a pressure switch is By attaching the flange surface to the upper surface of the flow channel body, the pressure of the flow channel was exerted on the diaphragm of the pressure switch. Also, the shutoff valve was attached to the left side surface of the flow path body.

Further, as described above, the diaphragm of the pressure sensor is provided with a vent hole in the case of the gas meter so that the gas pressure of the flow path is applied to one surface of the diaphragm and the outside air pressure is introduced to the other surface. Was there. The outside air from the vent has a structure in which it communicates with most of the rest of the gas meter except for the flow path (see particularly Japanese Utility Model Laid-Open No. 4-120330).

[0008]

[Problems to be solved by the device]

 In the conventional technology, the flow sensor and the piezoelectric film sensor are mounted on the rear surface of the flow channel body, the pressure switch is mounted on the upper surface of the flow channel body, and the shutoff valve is mounted on the left side surface of the flow channel body. Therefore, these sensors, switches, and valves are installed in multiple directions (three directions), which hinders automation of mounting when assembling the gas meter.

In addition, forming the mounting surface for mounting the sensor, switch, and valve on the flow path body not only complicates the die-casting mold splitting, but also impedes secondary processing of the mounting portion. There was a problem.

Furthermore, since the outside air pressure applied to one surface of the diaphragm of the pressure switch communicates with the entire remaining portion of the meter case except the inside of the flow path main body, the humidity of the outside air is collected from the ventilation hole into the meter case, and the temperature rises. There was a problem that the inside of the window glass, which is easily affected by the difference, is fogged due to dew condensation, which makes it difficult to read the integrated value of gas usage, which hinders meter reading.

There is also a problem that the moisture that has entered the meter case through the ventilation holes also condenses between the electrical connection terminals in the case, causing a short circuit between the terminals. In addition, there is a problem in that long-term use with a valid inspection period of 10 years causes problems due to corrosion due to ingress of moisture.

Therefore, an object of the present invention is to provide a fluidic gas meter having a security function capable of solving such a problem.

[0013]

[Means for Solving the Problems]

 To achieve the above object, a first invention is a flow sensor and a piezoelectric film sensor for detecting a gas usage amount, a pressure switch for detecting a gas pressure, and a shutoff for shutting off a gas in an emergency. In a fluidic gas meter with a valve, a flow sensor, a piezoelectric membrane sensor, a pressure switch, and a shutoff valve are attached to one side of the front surface or the rear surface of the flow path body equipped with the fluidic oscillation element. is there.

A second invention is the same as the first invention, except that the pressure switch (3) is covered with a pressure switch cover (37), and the inside of the pressure switch cover is provided in a meter case (26) with a vent hole (28A). ) Through the open air.

[0015]

[Action]

 Since the flow sensor, piezoelectric film sensor, pressure sensor, and shutoff valve are installed in one direction, automation of assembly is easy and assembly is easy. In addition, the die cutting of the flow path main body is simplified, and the secondary processing is also simplified because the processing directions are the same and the mass productivity is improved.

Further, in the second invention in which the pressure switch is surrounded by the pressure switch cover and the outside air is introduced into the inside of the pressure switch cover, the outside air enters from the ventilation hole of the meter case through the pressure switch cover. It is limited to the inside of the meter case, and enters the other parts inside the meter case such as the electronic unit, flow sensor, piezoelectric film sensor, shut-off valve, and other electrical functional parts, and the inside of the glass window that monitors the gas usage. No condensation.

[0017]

【Example】

 The first embodiment of FIGS. 1 to 3 corresponds to the first invention, in which 1 is a flow sensor, and its thermal tip portion 1A is disposed on the rear wall surface of the nozzle portion of the fluidic oscillation element and is a nozzle. To detect the flow velocity of the part. 2 is a piezoelectric film sensor for detecting fluid vibration of a fluidic oscillation element, 3 is a pressure switch for gas pressure detection, 4 is a shutoff valve, and these flow sensors 1 to 4 are die-cast flow path main bodies 5 It is mounted on the rear surface of.

In the flow path body 5, a mouthpiece 6 that forms an inlet 6A and a mouthpiece 7 that forms an outlet 7A are integrally formed side by side on the lower left and right when viewed from the front of the meter. It is a gas meter. A shutoff valve mounting seat 8, a valve seat 9, a pressure switch mounting seat 10, a flow sensor mounting seat 11, a piezoelectric film sensor mounting seat 12 and a fluidic oscillation element 13 are integrally formed in the flow path body 5. Has been done. Reference numeral 14 is a nozzle portion of the fluidic vibration element 13.

The flow path body 5 is arranged such that the depth of the nozzle portion 14 of the fluidic oscillation element 13 is in the front-rear direction, and a lid 16 is fixed to the front surface thereof with a screw 17 via a gasket 15. ing.

The flow sensor 1, the piezoelectric membrane sensor 2, the pressure switch 3 and the shutoff valve 4 are the flow sensor mounting seat 11, the piezoelectric membrane sensor mounting seat 12, the pressure switch mounting seat 10 and the shutoff valve on the rear surface of the flow path body 5. It is fixed to the mounting seat 8 by mounting screws 18, 19, 20 and 21, respectively.

Reference numeral 22 denotes a valve element of the shutoff valve 4, which is pressed against the valve seat 9 when the shutoff valve acts in an emergency and is applied to one surface of the diaphragm (not shown) of the pressure switch 3. Outside pressure (atmospheric pressure) is applied to the other side of the diaphragm.

Reference numeral 24 is a front case, and 26 is a rear case, and the meter case 26 is constituted by both of these cases. Reference numeral 27 is a seal member interposed between the front case 24 and the rear case 25. Reference numeral 28 denotes a vent hole provided on the lower slope of the rear case 25, which introduces the outside air pressure to the other surface of the diaphragm of the pressure switch 3.

Reference numeral 29 is a window glass provided on the front case 24, and is provided on the front surface of the display unit 30 so that the numerical value of the display unit 30 for displaying the gas usage amount (integrated value) can be visually recognized. Reference numeral 31 is a wiring plate, to which a terminal 32 of the flow sensor 1, a terminal 33 of the piezoelectric film sensor 2, a terminal 34 of the pressure switch 3 and a terminal 35 of the shutoff valve 4 are soldered and connected to an electronic unit (not shown). To do.

4 and 5 show a second embodiment of the present invention, which corresponds to the second invention. In this second embodiment, the flow sensor 1, the piezoelectric film sensor 2, the pressure switch 3 and the shutoff valve 4 are mounted on the front surface of the flow path body. In the drawing, only the mounting state of the pressure switch 3 and the shutoff valve 4 is shown, and the flow sensor 1 and the piezoelectric film sensor 2 are not shown. 8A is a shut-off valve mounting surface formed on the front surface of the flow path body 5, and 10A is a pressure switch mounting surface.

The flange 3 a of the pressure switch 3 is attached to the pressure switch mounting surface 10 A on the front surface of the flow path body 5 via the gasket 36. The gas pressure of the flow path body 5 is applied from the hole 23 to one surface of the diaphragm of the pressure switch 3. A pressure switch cover 37 is covered on the outside air introduction side which is the other side (the right side in FIG. 4) of the flange 3a, and the flange 37a of the pressure switch cover 37 sandwiches an O-ring-shaped first seal member 38. The pressure switch 3 and the flange 3a of the pressure switch 3 are overlapped with each other, and are fixedly mounted on the pressure switch mounting surface of the flow path body 5 together with the pressure switch 3 and the gasket 36 by three mounting screws 20.

A vent hole 37a communicating with a vent hole 28A provided in the front case 24 of the meter is opened on the front surface of the pressure switch cover 37 (the right end in FIG. 4). An insect screen 39 for preventing invasion is provided. Reference numeral 40 denotes a blind plate fixed to the front case 24 so as to cover most of the front case 24 except the lower part of the ventilation hole 28A, and prevents rainwater from entering the meter case. The front end shoulder portion of the cylindrical protrusion 37b forming the vent hole 37a of the pressure switch 3 is engaged with the annular recess of the front case 24 via the second O-ring seal member 41. Further, a cylindrical portion 37c through which the two terminals 34 penetrate is formed on the front surface of the pressure switch cover 37, and an O-ring-shaped third seal member 42 fitted to the inner surface of the cylindrical portion 37c is provided on the terminal 34 and the pressure switch. Seal with the cover 37.

Reference numeral 43 denotes an electronic unit that calculates the gas usage amount and numerically displays it on the display, or operates the shut-off valve 4 to shut off the gas in an emergency such as an abnormal flow rate or abnormal pressure of the gas. It is electrically connected to the flow sensor 1, the piezoelectric film sensor 2, and the pressure switch 3 via. Reference numeral 44 is a lead wire that connects the shutoff valve 4 and the wiring board 31A.

The outside air pressure (atmospheric pressure) is introduced so as to be applied to the other surface of the diaphragm of the pressure switch 3 through the communication holes 28A and 37a, and its introduction path is the flange 3a, the first seal member 38, and the pressure. Since it is surrounded by the switch cover 37, the second and third sealing members 41, 42 and the terminal 34 and is isolated from the other parts of the meter case 26, the humidity of the outside air (atmosphere) prevents the wiring board 31A inside the meter case. It is also possible to prevent the dew condensation on the lead wire 44, the terminals 32, 33 and 34, the electronic unit 43, the window glass 29 and the like.

The flange 3a of the pressure switch 3 is a metal plate, the pressure switch cover 37 is a resin, and the first, second, and third seal members 38, 41, 42 are NBR O-rings. Strictly speaking, the meter case 26 is composed of a part of the flow path main body 5, the front case 24 and the rear case 25, and is composed of the seal member 27 and the seal member 27A shown in FIG. Combined with the seal structure, it has a structure that does not ventilate outside air into the meter case other than the pressure switch.

As described above, in the second embodiment, the pressure switch 3 is attached to the front surface of the flow path body 5, so that the ventilation hole 28A of the front case 24 is guided to the atmosphere introduction side of the diaphragm of the pressure switch 3. A pressure switch cover 37 is attached between the flange 3a of the pressure switch 3 and the front case 24 to provide a simple structure such that the humidity of the atmosphere does not enter the majority of the meter case such as the electronic unit part and the window glass part. It was realized. Even when the pressure switch 3 is attached to the rear surface of the flow path body 5 as in the first embodiment, a pressure switch cover is provided to prevent condensation on the electronic circuit unit, terminals, window glass, etc. The same can be done as in the second embodiment.

[0031]

[Effect of device]

 Since the fluidic gas meter of the present invention is configured as described above, the flow sensor, the piezoelectric film sensor, the pressure switch, and the shutoff valve can be attached to the flow path body from the same direction, and these parts can be easily attached. Become. Further, the die cutting of the flow path body is simplified, and the secondary processing becomes easy.

Further, since it is possible to prevent outside air from entering into a portion other than a necessary portion, the window glass is not fogged to improve the visibility at the time of meter reading, and the rust preventive effect of the parts in the meter case and the electrical shortness are improved. Prevention can be expected.

[Brief description of drawings]

FIG. 1 is a rear front view of the first embodiment of the present invention showing a state in which a rear case and a wiring board are not attached.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view taken along the line BB of FIG.

FIG. 4 is a sectional view of a second embodiment of the present invention.

5 is a C-C view of FIG. 4. FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Flow sensor, 2 ... Piezoelectric film sensor, 3 ... Pressure switch, 4 ... Isolation valve, 5 ... Flow path main body, 13 ... Fluidic oscillation element, 24 ... Front case, 25 ... Rear case, 26 ... Meter case, 28A … Ventilation hole, 37… Pressure switch cover.

Claims (2)

[Scope of utility model registration request] 1. A fluidic gas meter having a flow sensor and a piezoelectric film sensor for detecting the amount of gas used, a pressure switch for detecting gas pressure, and a shutoff valve for shutting off gas in an emergency. A fluidic gas meter equipped with a flow sensor, a piezoelectric film sensor, a pressure switch, and a shutoff valve, which is integrally provided on one side of the front surface or the rear surface of a flow path body equipped with a fluidic oscillator. 2. The flue having a security function according to claim 1, wherein the pressure switch is covered with a pressure switch cover on the outside air introduction side, and the inside of the pressure switch cover is communicated with the outside air through a ventilation hole provided in the meter case. Dick type gas meter.