JPS6143019Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is an emergency gas cutoff valve that automatically stops the gas supply in the event of an emergency such as a gas leak or an earthquake. This relates to a drive circuit.

(Prior art) In order to avoid dangerous situations such as ignition and explosion caused by leaking gas, this type of gas cutoff valve does not maintain the closed state of the gas cutoff by continuing energization, but only for a short period of time in an emergency. A method is becoming widely adopted in which the closed state is maintained by applying electricity and maintaining the closed state without applying electricity.

This type of gas cutoff valve uses a permanent magnet's magnetomotive force to attract and hold a movable iron piece in a standby position.
The operating coil magnetically opposed to the permanent magnet is momentarily energized for a short time only in an emergency to reduce the attractive magnetic field of the permanent magnet to the movable iron piece, and the valve body interlocked with the released movable iron piece opens the valve opening. The gas closed state is maintained by means such as a spring that does not require energization.

Conventionally, this instantaneous short-time energization is performed using the discharge current of the capacitor. This basic circuit is as shown in FIGS. 1 and 4.

That is, the emergency state detector 1, such as a gas leak detection alarm or an earthquake sensor, and the gas cutoff valve drive circuit 2 may be separate or integrated, but in either case, the capacitor C of the drive circuit 2 Electric power is constantly supplied from the charging power source _P2 , and the capacitor C is maintained in a charged state.

When an emergency condition occurs and the output switch SW ₁ of the emergency condition detector 1 driven by the power source P ₁ closes,
Charge/discharge control switch linked to relay RL
SW ₂ is closed, and the charge stored in the capacitor C is discharged to the operating coil L of the gas cutoff valve 3, and the operating coil L is excited by this discharge current.

(Problems to be solved by the invention) In this discharge method, a charge/discharge control switch SW 2 receives a signal from the emergency state detector 1 and switches the capacitor C _of the drive circuit 2 from a charging state to a discharging state.
Therefore, it is necessary to incorporate a contact switch or a non-contact switch such as a semiconductor, and to add a separate circuit for its operation.

However, the increase in the number of parts due to the addition of such a circuit not only causes an increase in manufacturing costs but also inevitably becomes a factor in increasing the failure rate.

Given the original mission of gas shutoff valves, which is to ensure safety in emergencies, reliable operation is an absolute requirement, but as mentioned above, there is a risk that this may lead to a decline in reliable operation and reliability. Some conventional circuits have a drawback in this respect.

Therefore, the purpose of this invention is to simplify the circuit configuration, reduce the number of parts as much as possible, and improve the reliability of operation, while basically adopting an operating method of instantaneous short-time energization and no energization when the gas is closed. It is an object of the present invention to provide an emergency gas cutoff valve drive circuit that has the following features.

The emergency gas cutoff valve drive circuit of the present invention will be described below using the reference numerals in the attached drawings.
For the operating coil L driven by the same power source P as the emergency state detector 1 in the gas cutoff valve 3 which opens by short-time energization and closes the valve port with the valve body in conjunction with the movable iron piece. A capacitor C is connected in series, a bypass resistor R is connected in parallel to the capacitor C, and when the detection output of the emergency state detector 1 occurs, the capacitor C
is charged, and the operating coil L is excited by the charging current at this time. When the detection output of the emergency state detector 1 disappears, the electric charge stored in the capacitor C is discharged through the bypass resistor R, and the charge current is used to excite the operating coil L. This is to return C to an uncharged state.

(Embodiment) In the embodiment shown in FIGS. 3 and 4, when the emergency state detector 1 consisting of a gas leak detection alarm or an earthquake sensor is activated and its output switch SW ₁ is closed, the A single power supply P is applied to the uncharged capacitor C and the operating coil L connected in series to it.
A current momentarily flows from the gas cutoff valve 3 to close the gas cutoff valve 3, and at the same time, the capacitor C is charged.

Then, when the output signal of the gas leak detection alarm or the earthquake sensor 1 disappears, the bypass resistor R connected in parallel with the capacitor C discharges the charge in the capacitor C in preparation for the next drive. Return C to uncharged state. The resistance value of this bypass resistance R is the operating coil L
is sufficiently higher than the impedance of capacitor C.
It may be set to a value that is sufficiently higher than the initial charging impedance of .

(Effects of the invention) As described above, the gas cutoff valve drive circuit of the invention has the following features:
The operating principle is completely different from the conventional discharge type circuit,
The capacitor C, which is connected in series to the operation coil L connected to the same power source P as the emergency state detector 1 and is normally uncharged, is charged when the detection output of the emergency state detector 1 occurs. At this time, the charging current excites the operating coil L, and when the detection output of the emergency state detector 1 disappears, the capacitor C
Since this method discharges the electric charge that had been charged in the capacitor C through the bypass resistance R of the capacitor C and returns the capacitor C to an uncharged state, the power supply P for driving the emergency state detector 1 is sufficient as the power source. , charger C
There is no need to provide a separate power supply circuit to charge and store the battery, and in response to the detection output of the emergency state detector 1, the capacitor C can be moved from a non-charging state to a charging state, or conversely, it can be discharged from a charging state. There is no need for a charge/discharge control switch or switching circuit to change the state.

Furthermore, when a contact switch is inserted into the discharge circuit of a capacitor as a charge/discharge control switch in the conventional discharge method, a spark prevention circuit of the switch contact and a power supply circuit for operating the spark prevention circuit are connected to prevent leakage gas from igniting. However, in the charging type drive circuit of the present invention, these additional circuits are, of course, completely unnecessary.

Such reduction and simplification of the circuit not only brings about the economic effect of cost savings, but also reduces the probability of failure due to the reduction in the number of parts, which is the most required operation for an emergency gas cutoff valve. It also has the technical effect of further increasing the certainty and reliability of the system.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a conventional emergency gas cutoff valve drive circuit. FIG. 2 is a schematic system diagram of an emergency gas cutoff valve drive circuit according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of an emergency gas cutoff valve driving circuit according to another embodiment of the present invention. FIG. 4 is a specific circuit diagram of the conventional drive circuit shown in FIG. 1. FIG. 5 is a detailed circuit diagram of the drive circuit of the present invention shown in FIG. 3. 1... Emergency state detector, 2... Drive circuit, 3...
...Gas cutoff valve, C...Condenser, L...Operation coil, R...Shirt resistance, P...Power supply.

Claims (1)

[Scope of utility model registration request] In the gas cutoff valve 3, a movable iron piece attracted and held by a permanent magnet is released by short-term energization of the operating coil L, and the valve opening is closed by a valve body interlocked with the movable iron piece. When a capacitor C is connected in series to an operating coil L driven by the same power source P, and a bypass resistor R is connected in parallel to the capacitor C, a detection output of the emergency state detector 1 is generated. The battery C is charged, and the charging current excites the operation coil L, while the emergency state detector 1
When the detection output disappears, the charge stored in the capacitor C is discharged through the bypass resistor R,
An emergency gas cutoff valve drive circuit that returns the electricity storage device C to a non-charging state.