JP2933288B2 - Fluidic gas meter with micro 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 a fluidic gas meter with a microflow sensor in which a flow rate in a small flow rate range is detected by a micro flow sensor, and a flow rate in a flow rate range higher than that is detected by a fluid flow element. Things.

[0002]

2. Description of the Related Art In the case of a fluidic gas meter with a microflow sensor, measurement in a small flow rate region where it is difficult to measure accurately with a fluidic element is performed by an electronic microflow sensor. The values detected by the micro flow sensor and the fluidic element are calculated by using a flow rate calculation device (CP
U) is used to calculate the flow rate.

In a gas meter, all power sources depend on batteries.

The fluidic gas meter with a microflow sensor employs the above-described configuration and system. However, if an error occurs in the output of the microflow sensor or the fluidic element, the cause of the error is as follows. If you continue to use without recovering normally,
Not only an error occurs in the integrated value, but also a so-called microcomputer gas meter that monitors an abnormality based on a flow rate detected by a micro flow sensor and a fluidic element, for example, may not function properly. This is the same when a failure occurs in the arithmetic unit.

Further, since the power supply of the gas meter including the micro flow sensor employs a battery drive system, if the battery voltage drops, it will cause a major malfunction, and in this case, the gas meter functions normally. Disappears.

[0005] An object of the present invention is to provide a fluidic gas meter with a microflow sensor, which is configured to stop the gas immediately when an abnormality occurs in the microflow sensor, the fluidic element, the flow rate calculating device, and the battery so as not to cause a problem. To provide.

[0006]

The configuration of the present invention is as follows. Detection of the flow rate of a small flow rate region is carried out in a micro flow sensor, the gas meter of more of the flow rate detection is performed at fluidic element method in flow rate range, the Ma <br/> Lee black flow sensor and fluidic elements Compare the flow signals from both in a certain flow range where both operate, and if a difference of more than a certain range occurs in this flow signal, output a shut-off signal to a gas shut-off valve installed in the gas flow path along with the integration of the sensor abnormality check circuit, said Mai
Detected by Cloflow sensor or fluidic element
Abnormality of the arithmetic unit that calculates the gas flow rate based on the flow rate signal or
Diagnoses a failure, and if it is determined that the
Computing device check circuit that outputs a shutoff signal to the shutoff valve
The micro flow sensor and the full
Idick element and sensor abnormality check circuit and arithmetic unit
The voltage of the power supply circuit for the
Output a shut-off signal to the gas shut-off valve
Fluidic gas meter with a micro flow sensor incorporating a check circuit .

[0007]

The flow rate signals from the micro flow sensor and the fluidic element are input to a flow rate calculation device, where the flow rate calculation is performed, and displayed on a display unit, for example. In this operation, in a certain range in which the flow rate signals from both the micro flow sensor and the fluidic element are input, the flow rate is calculated based on both the flow rate signals, and a difference of a certain value or more occurs in the calculated value. In this case, the gas shutoff valve in the gas flow path is closed.

Similarly, since the flow rate calculating device is provided with a check circuit based on, for example, a watchdog timer method, if the check circuit is judged to be abnormal, the gas shutoff valve is closed. Further, the battery voltage is monitored by a voltage check circuit, and when the voltage drops below a certain value, the gas shutoff valve is closed.

[0009]

In FIG. 1, reference numeral 1 denotes a gas flow path, 2 denotes a gas cutoff valve attached to the gas flow path 1, and 3 denotes a gas flow detecting unit, which comprises a micro flow sensor 4 and a fluidic element 5. .

Reference numeral 6 denotes a flow rate calculating device (CPU). The flow rate calculating device 6 calculates a flow rate based on the flow rate signal from the gas flow rate detecting section 3 and displays the calculated value on a display section 8.
And the flow signal of the micro flow sensor 4 and the flow signal of the fluidic element 5 output from the gas flow detecting unit 3 in a certain flow rate range. And a sensor abnormality check circuit 9 for outputting a shut-off signal to the gas shut-off valve 2 via the sensor.

Reference numeral 11 denotes an arithmetic unit check circuit for checking an abnormality of the flow rate arithmetic unit 6. When an abnormality is detected by the circuit 11, a shutoff signal is sent to the gas shutoff valve 2 via an shutoff command circuit 12. Is output.

Reference numeral 13 denotes a voltage check circuit for checking the voltage of a battery 14 serving as a power supply for the entire gas meter. When the voltage check circuit 13 detects a voltage lower than a predetermined value, the gas cutoff valve 2 is shut off. The signal of is output.

[0013]

As described above, according to the present invention, when an abnormality occurs in the gas flow rate detection sensor, the flow rate calculation device and the battery voltage, the gas shut-off valve is immediately closed. There is no need to worry about it and it is effective for safety measures.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 gas flow path 2 gas cutoff valve 3 gas flow rate detection unit 4 micro flow sensor 5 fluidic element 6 flow rate calculation device 7 calculation circuit 8 display unit 9 sensor abnormality check circuit 10 cutoff command circuit 11 calculation device check circuit 12 cutoff command circuit 13 Voltage check circuit 14 Battery

Claims (1)

(57) [Claims] [Claim 1] Detection of the flow rate of a small flow rate region is carried out in a micro flow sensor, the detection of the flow rate at no more flow area in the gas meter of a method of performing in fluidic element, before
Both serial micro flow sensor and a fluidic device compares the flow signal from both at some flow rate region to operate,
If a difference of more than a certain range occurs in this flow signal,
In addition to incorporating a sensor abnormality check circuit that outputs a shutoff signal to a gas shutoff valve installed in the gas flow path,
Detected by micro flow sensor or fluidic element
Calculation device that calculates the gas flow rate based on the
Diagnosis of normal or malfunction, and when it is judged to be abnormal or malfunction,
Checking the arithmetic unit that outputs a shut-off signal to the gas shut-off valve
A circuit, further comprising the microflow sensor and
Fluidic element and sensor abnormality check circuit and function
The voltage of the power supply circuit for the arithmetic unit check circuit is low below a certain value.
Output a signal to the gas shutoff valve when shut down.
Fluidic gas meter with a micro flow sensor incorporating a voltage check circuit .