JP2000146100A - Gas safety device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent use of gas in a wrong connection condition, by providing an ultrasonic sensor for measuring a flow rate of gas flowing in a flow passage, confirming a connection direction of a gas passage by a control circuit by a flow rate measuring signal from this ultrasonic sensor, and actuating a cutoff valve in the case of reverse connection. SOLUTION: In this gas safety device, an operating signal is fed to an ultrasonic sensor drive circuit 3 from a control circuit 4, an instantaneous flow rate of gas flowing in a flow passage 2 is measured by operating an ultrasonic sensor 1, and an integrated gas amount used is measured based on this instantaneous flow rate data. Here two data t1, t2 measured through the ultrasonic sensor 1 are calculated as t1-t2 by the control circuit 4, and recognition as a flow rate measurement data by +, - of the calculation result or recognition as a wrong connection of a gas passage is determined. In the case of recognizing the wrong connection, a signal is fed to a cutoff valve drive circuit 6 from the control circuit 4, so as to prevent flowing of gas by closing a cutoff valve 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention measures a gas flow rate and shuts off a gas passage when an abnormal flow rate is measured.
The present invention relates to a gas safety device for ensuring safety in using gas.

[0002]

2. Description of the Related Art In recent years, when a gas meter for measuring the amount of gas used has measured a large amount of flow or has been used for an unusually long time, it is determined that an abnormality has occurred and the gas passage is determined. The one with a built-in security device that shuts off and ensures safety is widely used.

[0003] In this type of flow rate measurement system for a gas safety device, a membrane-type meter that measures the flow rate from the volume that has passed through the meter within a predetermined time, and an ultrasonic sensor that operates at a predetermined time interval to measure the instantaneous flow rate. Meters for measuring are common.

A conventional gas safety device using an ultrasonic sensor will be described with reference to FIG. When measuring the normal gas consumption, an operation signal is sent from the control circuit 4 to the ultrasonic sensor driving circuit 3 at predetermined time intervals, and the ultrasonic sensor 1 is operated to instantaneously flow the gas flowing through the flow path 2 Is measured.
Then, the integrated gas usage is measured based on the instantaneous flow rate data returned from the ultrasonic sensor driving circuit 3. Also,
The control circuit 4 determines whether or not the measured gas usage is abnormal. If the measured usage is abnormal, an operation signal is transmitted to the shut-off valve driving circuit 6 to close the shut-off valve 7 and stop the gas.

[0005]

However, in the flow measurement method using the ultrasonic sensor, the gas can flow in the direction opposite to the normal direction, and the flow rate cannot be measured in that case. there were.

[0006]

In order to solve the above-mentioned problems, according to the present invention, a state in which the gas flows in a direction opposite to the normal direction is detected by a flow rate signal from an ultrasonic sensor, a shutoff valve is closed, and Then, gas cannot be used.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A gas safety device according to a first means of the present invention comprises a flow path for flowing gas, an ultrasonic sensor for measuring a flow rate of gas flowing through the flow path, and an ultrasonic sensor. An ultrasonic sensor driving circuit for driving, a shut-off valve for shutting off a gas passage when an abnormality occurs, a shut-off valve driving circuit for operating the shut-off valve, and a control circuit for controlling the shut-off valve and the ultrasonic sensor; The control circuit checks the connection direction of the gas passage based on the flow rate measurement signal from the acoustic wave sensor, and operates the shut-off valve when the connection is reverse. As a result, it cannot be used with the reverse connection, and it is possible to prevent the flow rate from being undetected when the gas passage is incorrectly connected.

The gas safety device according to the second means of the present invention is the gas security device according to the first means, wherein the control circuit confirms the connection direction of the gas passage by a flow rate measurement signal from the ultrasonic sensor, and performs reverse connection. In some cases, the control circuit corrects the flow rate measurement signal according to a predetermined program so that it can be used in the same manner as in a normal connection.

Thus, even if the gas passage is reversely connected by mistake, the flow rate can be measured normally.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a configuration diagram of a gas safety apparatus according to Embodiment 1 of the present invention, and FIG. 2 is a flowchart thereof. The basic configuration is the same as that of the description of the conventional example, and the difference between the present embodiment and the conventional example is that the notification unit 5 is added.

According to this embodiment of the present invention, two data t measured through the ultrasonic sensor 1 as shown in FIG.
1 and t2 are calculated by the control circuit 4 as t1−t2, and it is determined whether to recognize as a flow measurement data or a misconnection of the gas flow passage based on the resulting value + −. I do.

When the connection is recognized as being erroneous, a signal is sent from the control circuit 4 to the shut-off valve drive circuit 6, and the shut-off valve 7 is closed to prevent gas from flowing.

The notifying unit 5 notifies the outside that there is an erroneous connection. The notification unit may be a display by a display, or may be a sound unit or a communication unit.

(Embodiment 2) FIG. 3 is a flow chart of a gas safety apparatus according to Embodiment 2 of the present invention.

According to this embodiment, as in the first means, the value calculated by the control circuit 4 is first determined as +-, and when + is recognized as normal measurement data, -Indicates that only the value is recognized as the measurement data by the predetermined correction program.

[0017] Thus, at the time of an erroneous connection, the measured data becomes a negative value and is not recognized, but the flow rate can be measured correctly.

[0018]

As is apparent from the above description, the gas safety device of the present invention has the following effects. Since the erroneous connection of the gas passage can be detected, it is possible to prevent the flow rate from being undetected at the time of the erroneous connection, and to prevent the use of gas in that state.

Further, there is no restriction on the connection direction of the gas passage,
Either way, the flow rate can be measured accurately.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a gas security device according to a first embodiment of the present invention.

FIG. 2 is a flowchart of the apparatus.

FIG. 3 is a flowchart of a gas security device according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram showing a conventional gas safety device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ultrasonic sensor 2 Flow path 3 Ultrasonic sensor drive circuit 4 Control circuit 5 Notification unit 6 Shutoff valve drive circuit 7 Shutoff valve

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Fujii 1006 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. F-term (reference) 3J071 AA02 BB11 BB14 EE02 EE18 EE25 EE31 EE37

Claims (2)

[Claims] A gas flow path for flowing a gas; an ultrasonic sensor for measuring a flow rate of the gas flowing through the gas flow path; an ultrasonic sensor drive circuit for driving the ultrasonic sensor; A shutoff valve that shuts off the passage, a shutoff valve drive circuit that operates the shutoff valve, and a control circuit that controls the shutoff valve and the ultrasonic sensor, wherein the control circuit is configured to control the control circuit based on a flow signal from the ultrasonic sensor. A gas safety device that checks a flow direction of a gas flowing through a gas passage and closes the shutoff valve if the flow is in a reverse direction. A gas flow path for flowing gas; an ultrasonic sensor for measuring a flow rate of the gas flowing through the gas flow path; an ultrasonic sensor drive circuit for driving the ultrasonic sensor; A shutoff valve for shutting off the passage, a shutoff valve drive circuit for operating the shutoff valve, and a control circuit for controlling the shutoff valve and the ultrasonic sensor, wherein the control circuit controls the gas by a flow signal from the ultrasonic sensor. A gas safety device which checks the flow direction of gas flowing in a passage, and in the case of reverse flow, the control circuit corrects the flow signal in accordance with a predetermined program and can be used in the same manner as in a normal connection.