JP3412229B2 - Gas shut-off device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas shut-off device for preventing a gas accident from occurring. 2. Description of the Related Art A conventional gas shut-off device of this type will be described with reference to FIG. In the figure, 1 is a shutoff valve for shutting off a gas passage, 2 is a flow measuring means for measuring a flow rate corresponding to a passing gas flow rate, 4 is a valve driving means for opening and closing the shutoff valve 1, and 5 is a valve driving means for opening and closing the shutoff valve 1. A valve opening / closing state detecting means 12 for detecting a difference in characteristic impedance and outputting an opening / closing signal is provided. A valve 12 outputs a driving signal to the valve driving means 4 to shut off the shut-off valve 1 when the gas flow rate measured by the flow rate measuring means is abnormal. A control unit that drives and determines the open / close signal from the valve open / closed state detection means 5 based on a fixed determination value to detect the open / close of the shutoff valve 1;
Reference numeral 8 denotes a warning notifying unit for notifying the open / closed state of the shut-off valve 1 by a warning. Further, as shown in FIG. 4, the characteristic impedance (equivalent inductance) of the shut-off valve 1 varies because the position of the plunger (iron core) is different between the open and closed states. The valve open / closed state detecting means 5 detects the difference in the equivalent inductance as a transient response characteristic with respect to the limiting resistance (by switching with the transistor in FIG. 5) by a circuit as shown in FIG. An opening / closing signal is output as times T1 and T2 when a certain level is exceeded. Control unit 12
Has compared the open / close signals T1 and T2 with a fixed determination value Ts to determine open / close. [0004] However, such a gas shut-off device is used when the shut-off valve 1 is changed in design or when a shut-off valve 1 having a different configuration (the same performance) is connected. In addition, it is necessary to frequently change the determination value Ts of the control unit 12. When this determination value is stored in a microcomputer or the like, it is necessary to change the microcomputer. Alternatively, in some cases, the determination cannot be made with the determination value Ts of the control unit 12. The equivalent inductance when the shut-off valve 1 is opened and closed is determined by the magnetic circuit of the shut-off valve 1 as shown in FIG. Even if the performance is the same, the equivalent inductance easily changes depending on how the magnetic circuit is assembled.
In extreme cases, the equivalent inductance during opening and closing may even reverse. In such a case, it is necessary to change the open / closed judgment value Ts of the control unit 12 in accordance with the magnetic circuit of the shutoff valve 1. Therefore, the gas shut-off device of the present invention can easily determine whether to open or close even if the magnetic circuit of the shut-off valve is changed due to a design change or a shut-off valve having the same performance but a different magnetic circuit configuration is connected. An object of the present invention is to improve the usability of the gas shut-off device by detecting the open / close state of the shut-off valve of the gas shut-off device. [0006] In order to achieve the above object, a gas shut-off device according to the present invention comprises a flow rate measuring means for measuring a flow rate corresponding to a passing gas flow rate, and a shut-off valve for shutting off a gas passage. A valve driving unit that opens and closes the shut-off valve, a valve open-close state detecting unit that detects a characteristic impedance of the shut-off valve and outputs an open-closed signal at the time of opening and closing, and a valve open-closed state output unit. Open / close determination value storage means for storing an open / close determination value based on the open / close signal, storage instruction means for externally instructing the open / close state to the open / close determination value storage means, and a gas flow rate abnormality due to the flow rate measurement means. In this case, a driving signal for driving the valve driving means is output. On the other hand, control means for comparing the open / close signal output from the valve open / closed state detection means with the open / close determination signal stored in the open / close determination value storage means to determine open / close, and a warning notification signal from the control unit And a warning notifying means for notifying a warning. According to the above construction, the gas shut-off device of the present invention determines the difference between the characteristic impedances when the shut-off valve is opened and closed when there is a storage instruction signal from the storage instruction means (such as an external switch). The open / close determination value storage means, which is detected by the detection unit, stores a valve open / close determination value based on the detected open / closed open / close signals. Immediately after opening / closing of the shut-off valve is performed by the valve driving means, etc., a difference in characteristic impedance of the shut-off valve is detected by the valve open / closed state detecting unit, and the control unit stores the detected open / close signal and the open / close determination value storage means. The open / close determination signal is compared with the open / close determination signal to determine whether the shutoff valve is open or closed, and a notification is issued to notify the user that the magnetic circuit of the shutoff valve has changed due to a design change, or that a shutoff valve with a different magnetic circuit configuration has the same performance. Even if
Opening and closing can be easily determined, and the open / closed state of the shutoff valve of the gas shutoff device can be detected to improve the usability of the gas shutoff device. An embodiment of the gas shut-off device according to the present invention will be described below with reference to the accompanying drawings. In FIG. 1, 1 is a shut-off valve for shutting off a gas passage, 2 is a flow measuring means for measuring a flow rate corresponding to a passing gas flow rate, 4 is a valve driving means for opening and closing a shut-off valve, and 5 is a conventional one. The difference in the equivalent inductance of the shut-off valve 1 is detected as a transient response characteristic with respect to the limiting resistance (by switching with the transistor in FIG. 5), and the opening and closing signals are set as time T1 and T2 as shown in FIG. The output valve opening / closing state detecting means 7 calculates the opening / closing determination value T's as T's = (T1 + T2) / 2 from the opening / closing signals T1 and T2 output from the valve opening / closing state detecting means 5, and calculates this value. Open / close determination value storage means for storing, 6 a switch as a storage instruction means for instructing the open / close determination of the open / close state to the open / close determination value storage means, and 3 a flow rate measurement means 2 detects an abnormality in the gas flow rate. In this case, a drive signal for driving the valve drive means 4 is output, and the open / close signal Ti output from the valve open / close state detecting means 5 is compared with the open / close determination signal Ts stored in the open / close determination value storage means 7. Control means 8 for judging the opening / closing by means of a warning is provided. When the equivalent inductance of the shut-off valve 1 changes (when the design of the shut-off valve 1 is changed, or when a differently configured shut-off valve 1 is connected), the memory is stored by pressing the switch of the storage instruction means 6 from outside. An instruction signal is output, and the open / close determination value storage means 7 obtains a determination value T's from the closed time T1 and the open time T2 detected from the valve open / closed state, and stores this. When there is an abnormality in the gas flow rate from the flow rate measuring means 2, the control section 3 sends a drive signal to the valve driving means 4 to close the shutoff valve 1. At this time, whether or not the shut-off valve 1 has been operated reliably is determined by comparing the open / close signal Ti sent from the valve open / close state detecting means 5 with the open / close determination signal T's stored in the open / close determination value storage means 7. If Ti <T's, it means that the shut-off valve 1 has operated reliably, and if reverse Ti>T's, it detects that it has not operated. In addition, even when the shut-off valve 1 is driven to open, it is possible to reliably detect whether or not the shut-off valve 1 is opened. The above-mentioned opening / closing determination value storage means 7 and control unit 3
This can be realized by using a calculation or determination function by a program operation of a microcomputer or the like. The above-mentioned open / close determination value storage means 7 and control unit 3
FIG. 2 shows a program flowchart up to detecting the open / closed state of the shut-off valve 1. In the figure, a process 20 determines whether or not there is a storage instruction signal from a switch of the storage instruction means 6. If there is no storage instruction signal, T ′ in process 21
It is determined whether or not s is stored. If T's is not stored, the process returns to step 20. On the other hand, if there is a storage instruction signal from the switch of the storage instruction means 6 in the processing 20, the processing calculates T's = (T1 + T2) / 2 in the processing 22, and the processing 23
Stores T's. Next, returning to the process 20, the process proceeds to the process 24 since Ts is stored in the process 21. In step 24, the opening / closing signal Ti from the valve opening / closing state detecting means 5 is fetched.
i is compared with Ts to determine whether the valve is open or closed, and the process proceeds to step 26. In process 26, the open / closed state of the shutoff valve 1 is displayed,
Alternatively, an abnormal display is made when the shutter is not closed when it should be closed or when it should not be opened when it should be opened. The timing of detecting the open / closed state is not immediately after the opening / closing of the shut-off valve 1 except for the impact detecting means (for example, detecting the electromotive force generated when the plunger of the shut-off valve 1 is moved by an impact). For example, it may be possible immediately after impact detection. Further, the current state of the shutoff valve 1 can be detected from outside the gas shutoff device by means of communication with the outside. As the valve opening / closing state detecting means 7, there is a method based on a resonance frequency by an equivalent inductance and a capacitor. In this case, the above configuration can be adopted by using the number of pulses in a predetermined time as the opening / closing signal. As is apparent from the above invention, the gas shut-off device of the present invention has a change in the magnetic circuit of the shut-off valve due to a design change, or a shut-off valve having the same performance but a different magnetic circuit configuration. Even in the case of being connected, the detection signal of the valve opening / closing state detecting means is updated and stored in the opening / closing determination value storage means by the storage instructing means, and the changed open / close determination reference value of the shutoff valve can be changed, so that the open / close determination can be easily performed. Thus, the usability of the gas shut-off device can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a functional block diagram of a gas shut-off device according to an embodiment of the present invention; FIG. 2 is a flowchart of the device; FIG. 3 is a conventional functional block diagram; Sectional view when the valve is open (b) Sectional view when the shut-off valve is closed [Figure 5] Typical transient response detection circuit diagram [Figure 6] (a) Characteristics showing the transient response waveform when the shut-off valve is closed (B) Characteristic diagram showing a transient response waveform when the shut-off valve is open [Explanation of symbols] 3 control means 4 valve driving means 5 valve open / closed state detecting means 6 storage instruction means 7 open / close determination value storage means 8 warning notification means

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor ▲ Yoshi ▼ Miho Tadashi 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-59-122818 (JP, A) JP-A 63-172097 (JP, A) JP-A-60-33425 (JP, A) JP-A-2-146387 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23N 5 / 24-5/26 F17D 5/02 F16K 17/36

Claims (1)

(57) [Claim 1] A flow rate measuring means for measuring a flow rate corresponding to a passing gas flow rate, a shutoff valve for shutting off a gas passage, a valve driving means for opening and closing the shutoff valve, Valve open / closed state detecting means for detecting a characteristic impedance of the shut-off valve and outputting an open / closed signal at the time of opening and closing; and an open / closed determination value storage for storing an open / closed determination value based on the open / close signal output from the valve open / closed state detecting means. Means, a storage instructing means for externally instructing the open / close state to the open / close determination value storage means, and a drive signal for driving the valve drive means when the gas flow rate is abnormal by the flow rate measuring means. On the other hand, control means for comparing the open / close signal output from the valve open / closed state detection means with the open / close determination signal stored in the open / close determination value storage means to determine whether the valve is open or closed, and a warning notification from the control means. By signal Gas cutoff apparatus provided with a warning notification unit that tell notification.