JPH0118327B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD This invention relates to a fuel cutoff control device that detects an abnormality in gas flow rate and cuts off gas supply. Conventional configuration and its problems There is a fuel cutoff control device that detects the gas flow rate and determines abnormalities such as a large amount of gas continuing to flow without change for a long time to prevent gas explosions and gas suicide. do. As this type of gas cutoff device, there is one having a configuration shown in FIG. In this figure 3, 26 is the gas meter 3
This is a flow rate sensor attached to 2 to detect the flow rate of gas. The flow rate sensor 26 is, for example, a combination of a magnet provided in a diaphragm constituting the gas meter 32 or a part of a link mechanism that transmits the reciprocating motion of the diaphragm to an indicator, and a reed switch that detects the position of this magnet. There is. The gas flow rate can be determined by measuring the time from when the reed switch is turned on to when it is turned on again. Reference numeral 28 denotes a self-holding manual return type solenoid valve which is a combination of a magnet and an electromagnetic coil provided in the gas flow path, and shuts off the gas flow path in response to a cutoff signal from the control unit 31 . This electromagnetic valve 28 is designed to self-maintain in an open state by the force of a magnet, thereby reducing battery consumption as a power source for the device. In addition, the shutoff operation is performed when the self-holding state is released as the electromagnetic force generated by passing current through the electromagnetic coil overcomes the force of the previous magnet that holds the valve in the open state. It will be done. In this way, once the cutoff state is established, the power of the magnet alone cannot
It is never open and no current needs to flow through it anymore. To open the valve, open it manually and use the magnet to hold it in place. Control part 3
1 receives a signal from the flow rate sensor 26, processes this signal according to a predetermined processing procedure, determines whether or not to shut off, and if the shut-off conditions are satisfied, sends a shut-off signal to the solenoid valve 28. Output against. As a processing procedure, for example, it is determined whether the flow rate detected by the flow rate sensor 26 continues to flow at a constant value for a predetermined time period. If it exceeds the flow rate, the equipment corresponding to the flow rate has been used for a longer period of time than the normal usage time, and such a state indicates some kind of abnormality, and a shut-off signal is output. Since this type of device uses a self-holding manual return type solenoid valve, it is necessary for the control section to recognize whether or not the valve is in the cutoff state after the control section outputs a cutoff signal.
For this purpose, for example, a magnet is placed in the movable part of the solenoid valve, and a reed switch is installed at a position where the solenoid valve is turned on when it is open and turned off when it is closed, and the opening and closing states of the valve are controlled by turning the reed switch on and off. Conventionally, recognition was carried out separately. This will now be explained in more detail using FIG. 4. Reference numeral 27 denotes a control circuit that converts the on/off state of the reed switch of the flow rate sensor 26 into voltage "Hi" and "Lo" signals using a resistor 27A. This signal is sent to the microcomputer 27B.
is received and processed according to a predetermined processing procedure stored as a program. If the cutoff conditions are satisfied, the microcomputer 27B outputs a cutoff signal, which turns on the transistor 27C, causing current to flow through the electromagnetic coil of the solenoid valve 28C.
Gas flow path is blocked. 29 is a return detection circuit;
Resistor 29B turns on and off reed switch 29C.
The signal is converted into voltage "Hi" and "Lo" signals and input to the microcomputer 27B. In the cutoff state, the reed switch 29C is off and the return detection circuit 29
The output is “Hi”. If the valve 28C is opened again by manual return operation, the reed switch 29C is turned on and the output of the return detection circuit 29 becomes "Lo", which causes the microcomputer 27B to detect that the valve 28C is open. I can recognize that. 30 is a battery as a device power source. A drawback of such a conventional device is that when the solenoid valve 28C is manually reset, the solenoid valve 28C becomes truly open, and it is not possible to know whether or not the control circuit 27 recognizes this. Purpose of the Invention The present invention is intended to solve these conventional problems, and is to provide a combustion shutoff control device that has a function of displaying the shutoff reason and that allows for reliable return operation without the need for a new display. This is to notify the operator of what has been done. Composition of the Invention In order to achieve this object, there are provided a display section for displaying a shutoff reason, a sensor input section for inputting a fuel flow rate signal, a reset signal input section for inputting a reset signal, and a flow rate for determining shutoff. The basic configuration is a main control unit that has a storage unit that stores data. With this configuration, the display content on the display unit can be reset after measuring the flow rate for a predetermined period of time using a signal from the reset signal input unit. It is easy to see that there are no leaks and that the device has completely returned to its open state. DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.
This will be explained using figures. In FIGS. 1 and 2, 1 is a power source section consisting of a battery, 2 is a clock generator section that generates a clock signal that is a reference for time counting, 3 is a sensor input section that inputs a fuel flow rate signal, and 4 is, for example, An external sensor input section for inputting an external sensor such as an earthquake sensor, 5 a return signal input section to which a return signal is input when the cut-off section is reset, 6 a main control section consisting of a microcomputer, and 7 a plurality of different A display section 8 is made up of a light emitting diode to display the status and shows the reason for the cutoff, and a cutoff section 8 is made up of a self-holding electromagnetic valve that cuts off the fuel supply path. Next, the operation of the above configuration will be explained. First, when the power supply section 1 is turned on, the entire control device becomes operational. The main control section 6 consists of a microcomputer, which inputs the flow rate signal from the sensor input section 3 and the clock signal from the clock generation section 2, and measures the fuel flow rate per unit time from the number of flow rate signals at arbitrary time intervals. . Flow rate data that serves as a reference for shutting off is registered in advance in the microcomputer, and the measurement results and the flow rate data are compared. The registered flow rate is, for example, data on the maximum passing amount that must not be exceeded under normal usage conditions as specified by the gas meter in each home in the gas supply route, or the elapsed time at the same flow rate. If the time stipulated in the above is exceeded, it is determined that the appliance was forgotten to be turned off, and the flow rate data is used to shut it off.
As a result of the comparison, for example, if the maximum flow rate data is exceeded, the data will be displayed as shown in (a) of the table, and if the time exceeds the same flow rate, the data will be outputted to the display section 7 as shown in the table (b). A cutoff output is also provided to the cutoff section 8.

[Table] * However, ○ is on and × is off. In this way, various flow rate data that can be used as criteria for shutting off, etc. are registered in the main control unit 6, and it is possible to detect when a gas valve is opened or a device is forgotten to be turned off. At the same time, display data is output according to the type of flow rate data to notify the reason. Furthermore, when a return signal is input to the return signal input circuit 5 during manual return operation of the cutoff section 8, the flow rate is measured again and after confirming that there is no flow pulse for a predetermined period of time, the reason for the cutoff is erased and the return is resumed. It is possible to notify the operator that the operation has been performed reliably. Further, by measuring the flow rate from when the return signal is input until the reason for the shutoff is removed, it is possible to prevent the terminal device from being returned with the door open, for example, during a return operation. FIG. 2 shows a specific embodiment based on the block diagram of FIG. The same numbers as in FIG. 1 indicate the same contents. 10 is a crystal oscillator whose frequency is divided by a counter 21, and is connected to the input terminal of the main controller 6, for example.
This is to generate a clock pulse with a period of 0.1 seconds on _I1 . Reference numeral 11 is a reed switch for measuring the fuel flow rate, which is installed close to the meter so that a magnet responds to the gas flow rate, for example.
Transistor 12 responds to the operation of reed switch 11 via resistor 9 and the like. Therefore, the main control unit 6 measures the fuel flow rate per unit time at any given time based on the number of pulses coming into the input terminal _I3 and the time counted by the clock pulses coming into the input terminal _I1 . be able to. 13,1
4 and 15 are transistors that supply current to light emitting diodes (LEDs) 16, 17, and 18 connected to each other, and these are controlled by output terminals O ₁ , O ₂ , and O ₃ of the main control unit 6. Ru. 19 is a transistor for driving the self-holding shutoff valve 20. 22 is a transistor that turns on and off in response to a signal input to the external sensor terminal 25. Reference numeral 23 denotes a switch for generating a return signal, which may be configured to be turned on when the shutoff valve 20 is reset, and is inputted to the input terminal I ₄ of the main control unit 6 via the transistor 24 . Effects of the Invention As described above, the fuel cutoff control device of the present invention provides the following effects. It is possible to notify the operator that the return operation has been reliably performed without providing a new indicator. At the time of return, it is also possible to prevent accidents such as gas leakage that would occur if the terminal device was returned with its handle left open. The reason for the shutdown is displayed even during recovery (during a leak check), so even if the user performs the recovery operation in a hurry, the reason for the disconnection will not be overlooked and maintenance can be performed properly according to the reason. Can be done.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a fuel cutoff control device according to an embodiment of the present invention, FIG. 2 is a circuit diagram of the same device, FIG. 3 is a block diagram of a conventional fuel cutoff control device, and FIG. 4 is a block diagram of a conventional fuel cutoff control device. FIG. 3...Sensor input section, 5...Return signal input section, 6...Main control section, 7...Display section, 8...Shutoff section.

Claims (1)

[Claims] 1. A sensor input section into which a fuel flow rate signal is input, a cutoff section that cuts off the fuel supply path, a display section that displays the reason for the cutoff, and a return signal input section that detects when the cutoff section is reset. , the display section,
Signals from an output terminal that drives each of the cutoff parts, the sensor input part, and the return signal input part are inputted, and at least a plurality of flow rate data serving as a reference for driving the cutoff part and cutoff reason data related to the flow rate data are input. and a main control section that has a program ROM registered in advance and that resets the display data of the display section after comparing the flow rate sensor signal with a predetermined flow rate for a predetermined period of time when the return signal is input. .