JP2005233635A - Gas shut-off device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent wrong detection of flow rate measurement caused by fluctuation, vibration or impact of a gas supply pressure. <P>SOLUTION: This device is equipped with a positive flow rate detection circuit 7 for receiving a positive voltage signal a outputted from a flow sensor 6 when the polarity of a permanent magnet 4 is changed from the N-pole to the S-pole, and outputting a positive flow rate signal b, a negative flow rate detection circuit 8 for detecting a negative voltage signal c outputted from the flow sensor 6 when the polarity of the permanent magnet 4 is changed from the S-pole to the N-pole, and outputting a negative flow rate signal d, and a microcomputer 9 for measuring the positive flow rate signal b and the negative flow rate signal d, and determining it as a gas flow rate. Hereby, wrong detection of flow rate measurement can be prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a gas shut-off device for ensuring safety in use of gas when a gas is used after a gas meter.

FIG. 4 shows a conventional gas shut-off device described in Patent Document 1 regarding this type of gas shut-off device. As shown in FIG. 4, the on / off operation of the reed switch 13 provided facing the passing position of the permanent magnet 4 attached to the rotating body 5 rotating in conjunction with the membrane type measuring unit for measuring the passing flow rate is shown as the flow rate. The detection circuit 14 converts it into an electrical signal. The flow rate detection circuit 14 outputs a flow rate signal voltage obtained by dividing the voltage of the battery 1 by the resistors 15a and 15b. The microcomputer 9 receives an on / off flow rate signal from the flow rate detection circuit 14. The microcomputer 9 is configured to monitor the flow rate value and leakage of the gas flow rate, shut off the shut-off valve 2 via the shut-off valve drive circuit 3 in the event of an abnormality, and perform notification by display on the display unit 10. Is configured to be supplied from the battery 1.
JP 2003-121214 A

  However, in the conventional gas shut-off device, since the reed switch is turned on / off by the magnetic field of the permanent magnet, the reed switch is a mechanical contact, so the contact is turned on / off due to fluctuations in gas supply pressure, vibration, or shock. There are problems such as misdetection of measurement, and there are problems such that the contact interval of the reed switch changes and the on / off moving value shifts, making it impossible to detect the flow rate.

  Furthermore, if the permanent magnet attached to the rotating body that rotates in conjunction with the unit weighing stops within the ON magnetic field of the reed switch, the flow rate detection circuit continues to flow current through the voltage dividing resistor, causing unnecessary power consumption. It has the problem of increasing and shortening the battery life.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a gas shut-off device that can prevent erroneous detection of flow rate measurement due to fluctuations in gas supply pressure, vibration, or impact.

  In order to solve the above-mentioned conventional problems, a gas shut-off device according to the present invention includes a battery as a control power supply, a shut-off valve provided in a gas flow path, a shut-off valve drive circuit for driving the shut-off valve, and a unit A magnet having N polarity and S polarity passing through a fixed position every time the flow rate is measured, and a positive voltage signal and a negative voltage signal each time the magnetic field in the iron core having a large Barkhausen effect is reversed. The flow rate sensor for outputting, the positive flow rate detection circuit for detecting the positive voltage signal and outputting the positive flow rate signal, the negative flow rate detection circuit for detecting the negative voltage signal and outputting the negative flow rate signal, and the positive flow rate signal alternately When the negative flow rate signal is received, it is determined that the gas flow rate is a unit flow rate, and control means for integrating the gas flow rate is provided.

  According to the above, in order to determine the gas flow rate using the positive voltage signal and the negative voltage signal that are alternately generated by reversing the magnetic field of the magnet that passes through the fixed position every unit flow rate measurement, the vibration, shock, gas Misdetection of gas flow rate due to supply pressure fluctuation can be prevented. Further, the flow sensor can be a non-power source.

  According to the gas cutoff device of the present invention, in order to determine the gas flow rate with the positive voltage signal and the negative voltage signal that are alternately generated by reversing the magnetic field of the magnet that passes through a fixed position for each unit flow rate measurement, It is possible to prevent erroneous detection of the gas flow rate due to vibration, impact, and gas supply pressure fluctuation, and to improve flow rate detection accuracy and reliability.

  The first invention is a battery as a control power supply, a shut-off valve provided in a gas flow path, a shut-off valve drive circuit that drives the shut-off valve, and an N polarity that passes through a fixed position for each unit flow rate measurement. A magnet having S polarity, a flow sensor that is provided facing the magnet and outputs a positive voltage signal and a negative voltage signal each time the magnetic field in the iron core having a large Barkhausen effect is inverted, and detects the positive voltage signal A positive flow rate detection circuit for outputting a positive flow rate signal, a negative flow rate detection circuit for detecting the negative voltage signal and outputting a negative flow rate signal, and alternately receiving the positive flow rate signal and the negative flow rate signal, Control means for determining the gas flow rate and integrating the gas flow rate is provided.

  According to the above, in order to determine the gas flow rate using the positive voltage signal and the negative voltage signal that are alternately generated by reversing the magnetic field of the magnet that passes through the fixed position every unit flow rate measurement, the vibration, shock, gas Misdetection of gas flow rate due to supply pressure fluctuation can be prevented. Further, the flow sensor can be a non-power source.

  In the second invention, in particular, the control means of the first invention is configured not to determine the gas flow rate when the gas flow rate is detected a plurality of times when the positive flow rate signal and the negative flow rate signal are input within a predetermined time. Is.

  According to the above, when the positive flow rate signal and the negative flow rate signal that are greater than or equal to the normally assumed gas flow rate are input a plurality of times, it is determined as an erroneous signal due to noise, vibration, shock, or gas supply pressure fluctuation. Misdetection of the gas flow rate can be prevented.

  According to the third aspect of the invention, in particular, when the control means of the first or second aspect of the invention is opened after the gas flow rate is detected after the gas flow passage is shut off, either the positive flow rate signal or the negative flow rate signal is received. The gas flow rate is determined.

  According to the above, when the gas flow path is opened, the gas leakage after the gas shut-off device can be detected earlier.

  In the fourth invention, in particular, when the control means of any one of the first to third inventions detects the gas flow rate when either the positive flow rate signal or the negative flow rate signal is continuously input, the flow rate detection circuit It is configured to be judged as abnormal.

  According to the above, the soundness of the flow rate detection circuit can be confirmed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiment.

(Embodiment 1)
FIG. 1 is a configuration diagram of a gas cutoff device according to Embodiment 1 of the present invention. 2 is a structural diagram of the flow sensor, and FIG. 3 is a timing chart showing a flow signal output from the flow sensor.

  In FIG. 1, a battery 1 as a control power source, a shut-off valve 2 provided in a gas flow path, a shut-off valve drive circuit 3 for driving the shut-off valve 2, and a permanent magnet 4 are a membrane type that measures a passing flow rate. The N-polarity and S-polarity magnets are attached to the rotating body 5 that rotates in conjunction with the weighing unit, and are arranged at 180 ° positions. The flow sensor 6 is provided facing the passing position of the permanent magnet 4 and outputs a pulse voltage every time the polarity of the permanent magnet 4 is reversed from the N pole to the S pole and from the S pole to the N pole. A positive flow rate detection circuit 7 using a transistor and a resistor for receiving a positive voltage signal a output from the flow rate sensor 6 when the polarity of the permanent magnet 4 changes from N pole to S pole; A negative flow rate detection circuit 8 using a transistor and a resistor for detecting a negative voltage signal c output from the flow rate sensor 6 when the polarity of the permanent magnet 4 changes from the S pole to the N pole; And a microcomputer 9 as a control means for measuring the positive flow rate signal b output from the positive flow rate detection circuit 7 and the negative flow rate signal d output from the negative flow rate detection circuit 8 to determine the gas flow rate. The computer 9 is configured to monitor the flow rate value and leakage of the gas flow rate, shut off the shut-off valve 2 via the shut-off valve drive circuit 3 in the event of an abnormality, and alert the display unit 10. 1 It is an al supply configuration.

  Next, the operation and action will be described. The flow sensor 6 has a structure as shown in FIG. 2, and 11 is an iron core having a large Barkhausen effect, and a detection coil 12 is wound around it. As an iron core having a large Barkhausen effect, an amorphous element having a fiber shape is disclosed. When the polarity of the applied magnetic field in the direction shown in the figure is reversed, positive and negative pulse voltages are induced in the detection coil 12 in response to a sudden change in magnetic flux.

  The pulse voltage is synchronized with the polarity of the permanent magnet 4 passing through the flow sensor 6 as shown in FIG. 3, and the flow sensor 6 has a polarity of the permanent magnet 4 from N pole to S pole and from S pole to N pole. A pulse voltage is output each time the signal is inverted. A positive flow rate detection circuit 7 that receives a positive voltage signal a output from the flow sensor 6 when the polarity of the permanent magnet 4 changes from N pole to S pole, and outputs a positive flow signal b, and the permanent magnet 4 from the flow sensor 6. The negative flow rate signal b output from the positive flow rate detection circuit 7 and the negative flow rate detection circuit 8 that detects the negative voltage signal c that is output when the polarity changes from the S pole to the N pole and outputs the negative flow rate signal d. The negative flow rate signal d output from the negative flow rate detection circuit 8 is measured, and when both are input, it is determined that the unit metered gas flow rate has passed.

  Therefore, in order to determine the gas flow rate based on the positive voltage signal and the negative voltage signal that are alternately generated by reversing the magnetic field of the magnet that passes through a fixed position for each unit flow rate measurement, vibration, shock, and gas supply pressure fluctuations are determined. Can prevent misdetection of gas flow rate. Further, the flow sensor can be a non-power source.

  The microcomputer 9 measures a predetermined time and does not determine the gas flow rate when the positive flow signal b and the negative flow signal d are input a plurality of times within the predetermined time.

  Next, the operation and this action will be described. Normally, the gas flow rate through the gas shut-off device is within 10 times the unit meter per second. However, when the permanent magnet 4 vibrates due to fluctuations in gas supply pressure or the like, a flow rate signal more than 10 times the unit meter is erroneously input per second even though the gas flow rate is actually small. There is.

  Therefore, the microcomputer 9 measures a predetermined time when receiving the positive flow signal b or the negative flow signal d, and does not determine the gas flow rate when the positive flow signal b or the negative flow signal d is input within the predetermined time. Further, when a positive flow rate signal b or a negative flow rate signal d is received, a predetermined time is measured, and when the positive flow rate signal b or the negative flow rate signal d is not input within the predetermined time, it is determined as a gas flow rate.

  Therefore, when a positive flow rate signal and negative flow rate signal that are greater than the normal assumed gas flow rate are input multiple times, an erroneous signal due to noise, vibration, shock, or gas supply pressure fluctuation is detected. Can be prevented.

  In addition, when the microcomputer 9 is opened after the gas flow path is shut off, the microcomputer 9 determines that the gas flow rate is received by receiving either the positive flow rate signal b or the negative flow rate signal d. When the plug is opened, the gas leakage after the gas shut-off device can be detected earlier.

  The microcomputer 9 determines that the flow rate detection circuit is abnormal when one of the positive flow rate signal b and the negative flow rate signal d is continuously input. If the detection circuit 8 is normal, the positive flow rate signal b and the negative flow rate signal d are alternately input to the microcomputer 9 every time there is a gas flow rate, but the positive flow rate detection circuit 7 or the negative flow rate detection circuit 8 Occurs, the positive flow rate signal b and the negative flow rate signal d are not input to the microcomputer 9 alternately.

  Accordingly, the microcomputer 9 determines that the flow rate detection circuit is abnormal when either the positive flow rate signal b or the negative flow rate signal d is continuously input.

  Therefore, the soundness of the flow rate detection circuit can be confirmed.

  As described above, the gas shut-off device according to the present invention has the gas flow rate with the positive voltage signal and the negative voltage signal that are alternately generated by reversing the magnetic field of the magnet passing through the fixed position every unit flow rate measurement. Therefore, it is possible to prevent erroneous detection of the gas flow rate due to vibration, impact, or gas supply pressure fluctuation. In addition, since the flow sensor can be a non-power source, it can also be applied to measuring instruments such as a water meter and an electric meter that measure the flow rate by changing the magnetic field.

Configuration diagram of a flow rate detection device according to a first embodiment of the present invention. Configuration diagram of the flow sensor according to the first embodiment of the present invention. Timing chart showing flow rate signal of embodiment 1 of the present invention Configuration diagram of conventional gas meter flow rate detection device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery 2 Shut-off valve 3 Shut-off valve drive circuit 4 Permanent magnet (magnet)
5 Rotating body 6 Flow rate sensor 7 Positive flow rate detection circuit 8 Negative flow rate detection circuit 9 Microcomputer (control means)

Claims (4)

A battery as a control power source, a shut-off valve provided in the gas flow path, a shut-off valve drive circuit for driving the shut-off valve, and a magnet having N polarity and S polarity that pass through a fixed position every unit flow rate measurement And a flow rate sensor that outputs a positive voltage signal and a negative voltage signal each time the magnetic field in the iron core having a large Barkhausen effect is reversed, and detects the positive voltage signal and outputs a positive flow rate signal. A positive flow rate detection circuit that detects the negative voltage signal and outputs a negative flow rate signal, and alternately receives the positive flow rate signal and the negative flow rate signal to determine that the unit gas flow rate is a gas flow rate. A gas shut-off device composed of control means for integrating the flow rate. The gas shut-off device according to claim 1, comprising a control means that does not determine the gas flow rate when a positive flow rate signal and a negative flow rate signal are input a plurality of times within a predetermined time. 3. The gas shut-off device according to claim 1 or 2, comprising a control means for determining the gas flow rate when receiving either the positive flow rate signal or the negative flow rate signal when the plug is opened after the gas flow passage is shut off. The gas shut-off device according to any one of claims 1 to 3, comprising a control means that determines that the flow rate detection circuit is abnormal when either the positive flow rate signal or the negative flow rate signal is continuously input.

Images