JPH0226512B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a gas cutoff device for preventing explosion accidents caused by city gas, propane gas, etc.

Configuration of conventional examples and their problems Conventional gas cutoff devices include, for example,
As disclosed in Japanese Patent No. 140981, there is a structure shown in FIG. That is, gas meter 1,
A flow rate sensor 2 that outputs a flow rate signal according to the amount of gas passing through the gas meter is attached, and the flow rate signal from the flow rate sensor 2 is input to a cutoff determination section 3. This cutoff determination section 3 calculates the amount of gas passing through the gas meter from the flow rate signal, and outputs a cutoff signal when the gas amount as the calculation result satisfies a predetermined condition stored in advance. This cutoff signal activates a solenoid valve provided in the gas passage to cut off the gas passage. From the point of view of the safety of the entire device, a battery is used as the power source for the device, so the solenoid valve is of a one-shot self-holding type. Therefore, although the valve is opened manually, the solenoid valve 4 outputs a return signal when the valve is opened, etc., in order to notify the shutoff determining section 3 that the valve has been opened. FIG. 2 is a block diagram of the shutoff determining section 3 and the electromagnetic valve 4. A flow rate signal from the flow rate sensor 2 is inputted to the input terminal i1 of the microcomputer 6 via the signal processing circuit 5. A typical flow rate sensor is a combination of a magnet provided in a mechanism that operates in connection with metering in a gas meter, and a reed switch that detects the magnetic field of the magnet. A typical signal processing circuit 5 is a chatter absorption circuit of a reed switch that constitutes the flow rate sensor 2. The microcomputer 6 calculates the amount of gas passing through the meter from the flow rate signal, and when the calculation result satisfies a predetermined condition stored in its ROM part, the microcomputer 6 outputs the output terminal O.
1 to output a cutoff signal for a predetermined period of time. This cutoff signal drives the driver 7, energizes the coil 4A of the solenoid valve 4, and cuts off the gas passage. When the solenoid valve 4 is in the closed state, a reed switch 4B as a valve position detector provided on the solenoid valve 4 is turned off. When the solenoid valve 4 is opened manually, the reed switch 4A is turned on, and this is inputted to the microcomputer 6 as a return signal, and the operation based on the signal from the flow rate sensor 2 is resumed thereafter. When the solenoid valve 4 is in the closed state, the microcomputer 6 constantly monitors whether a reed switch 4B on signal is input as a return signal. The disadvantage of this device is that even when the solenoid valve 4 is in a closed state, the microcomputer 6 is always in operation, so even if the microcomputer uses a CMOS process as a low power consumption process, it cannot be used as a device power supply. This means that the battery consumption is large.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and aims to reduce the current consumption of the device when the solenoid valve is closed, and to extend the life of the battery as the device's power source.

Configuration of the Invention In order to achieve the above object, the gas cutoff device of the present invention includes a cutoff determination section, a standby mode,
It is equipped with a mode switching terminal that can switch from standby mode to normal mode by external input, and the reset signal of the cut-off section is input to this mode switching terminal.By using this standby mode, electromagnetic This greatly reduces battery consumption when the valve is closed, thereby allowing the battery to be used for a long period of time.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 3, the cutoff determination section 8 includes a microcomputer 9 having a standby mode. The microcomputer 9 is switched from normal mode to standby mode by software. Here, the normal mode indicates a state in which the microcomputer 9 is operating normally, and all functions are in an operating state. On the other hand, in the standby mode of the microcomputer 9, most of its functions are stopped, so its current consumption is reduced to about one tenth of that in the normal mode.
Once the microcomputer 9 enters standby mode, its mode switching input terminal RS1
Then, the standby mode is maintained until a return signal from the reed switch 4B is input, and when the return signal is input, the mode returns to the normal mode. In other words, in Figure 4,
In the normal mode, the microcomputer 9
A cutoff signal is output at time t1 (Figure 4b). As a result, at time t2, when the solenoid valve 4 serving as a shutoff section is brought into a closed state, the reed switch 4B is switched from on to off (FIG. 4c). At time t3, the predetermined time has elapsed from time t1, so the output of the cutoff signal is stopped.
Thereafter, the microcomputer 9 switches from the normal mode to the standby mode at time t4 (FIG. 4A).
At time t5, when the solenoid valve 4 is opened, the reed switch 4B is turned on, and this is input to the mode switching terminal RS1 of the microcomputer 9 as a return signal, so the microcomputer 9 switches from standby mode to normal mode again. Then, reading the signal from the flow rate sensor 2 is started.

As described above, according to this embodiment, the microcomputer constituting the shutoff determination unit is a microcomputer with a standby function, and when the solenoid valve is in the closed state, the microcomputer is placed in standby mode, thereby placing the shutoff determination unit in standby mode. By reducing the current consumption of the device during this period, it is possible to use the battery as a power source for the device for a long period of time.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) By setting the cutoff determination section to standby mode, current consumption when the cutoff section is closed can be reduced.

(2) Since the current consumption is low, when using the same battery, it can be used for a longer period of time than the conventional example.

(3) Since the current consumption is low, the battery capacity can be lower than that of the conventional example for the same battery life, thereby reducing the battery size and making the entire device smaller and lighter.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of a general gas cutoff device.
FIG. 2 is a block diagram of the same device, FIG. 3 is a block diagram of a gas cutoff device according to an embodiment of the present invention, and FIG. 4 is a timing chart for explaining the operation of the device. 1...Gas meter, 2...Flow rate sensor, 4...
Solenoid valve, 8... cutoff determination section.

Claims (1)

[Claims] 1. A flow rate sensor installed in the gas passage and proper gas usage conditions are memorized in advance, and the usage status is determined based on the flow rate signal from the flow rate sensor, and if the proper usage conditions are deviated from, it is determined to be abnormal and a cutoff signal is issued. A shutoff determination section, a shutoff section that shuts off a gas passage in response to a shutoff signal from the shutoff determination section and outputs a return signal upon restoration, and a battery as a power source of the device, and the shutoff determination section is configured to operate in a standby mode. and a normal mode, and enters a standby mode after issuing a cutoff signal, and is provided with a mode switching terminal capable of switching from the standby mode to the normal mode,
A gas cutoff device configured to input a return signal of the cutoff section to the mode switching terminal.