JPS6225906B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for shutting off fluid such as fuel gas, and in particular, it is normally open and does not obstruct the flow of fluid, but if any abnormality occurs, it is immediately closed to shut off fluid. The present invention relates to a fluid breaker that reliably prevents the flow of fluid.

For example, in the event of an unexpected accident such as a gas leak or an earthquake, it is absolutely necessary to first shut off the gas to prevent it from causing a major secondary disaster. By the way, fluid circuit breakers used for such purposes are required to meet strict conditions different from those of ordinary valve devices. First of all, this type of fluid circuit breaker not only consumes no power when it is on standby, but also can be driven with a small amount of power. It must be possible for the system to be maintained without any problems. That is, it must be mechanically triggered. This is to prevent the device from returning to its pre-operation state even if an accident such as a power outage occurs later. This is extremely important in order to eliminate the inconvenience of, for example, having once cut off the gas due to a gas leak, but then due to an accident such as a power outage, the circuit breaker returns to its original state and the gas leak returns again. That's true.

Furthermore, considering the purpose of this type of fluid circuit breaker, it is not operated on a daily basis and is left in an inoperative standby state for a long period of time, so there is no risk of failure. However, it is very difficult to discover. Therefore, in this type of fluid circuit breaker,
The structure is as simple as possible, and even if it is left inactive for a long period of time, it can operate reliably and quickly, and it is sufficiently designed to prevent breakdowns in the unlikely event that it does. Must have high reliability.

In view of the above conditions, the reality is that conventional fluid circuit breakers are still unsatisfactory. For example, as shown in Utility Model Application Publication No. 52-35625, a hard magnetic ball supported in a downward position by the resultant force of the attraction force of a permanent magnet and its own weight is levitated by the magnetomotive force of a solenoid, and is then floated by another permanent magnet above. Fluid cutoff valves that close the flow path by attraction are also known, but the operating force of the electromagnetic drive device is generally weak, and even with this, the solenoid itself is required to levitate the hard ball attracted by the permanent magnet. However, it was not only extremely large and costly, but also had major problems in terms of reliability.

This invention was made in view of the above circumstances, and its purpose is to first simplify the configuration, increase reliability, and prevent breakdowns even if left in an inactive state for a long period of time. It is possible to operate reliably by eliminating critical elements and without causing any problems.
Moreover, it is an object of the present invention to provide a fluid circuit breaker that can be realized at low cost. A further object of the present invention is to reduce the required drive current for operation, enable trigger operation, facilitate movement with gas leak detectors, earthquake detectors, etc., and speed up operation. An object of the present invention is to provide a fluid breaker that can quickly respond to the operation of a sensor or the like.

Hereinafter, embodiments of a fluid circuit breaker according to the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1a and 1b show an embodiment of a fluid circuit breaker according to the present invention. First, a valve chamber 6a is formed in a non-magnetic casing 6 disposed horizontally. A magnetic movable member 2 is provided integrally with the valve body 1, and the valve body 1 is connected to the valve seat 1a.
a first spring 3 that elastically biases the magnetic movable member 2 in a direction away from the casing 6; an annular permanent magnet 4; an excitation coil 5 disposed outside the casing 6 at an intermediate position between the permanent magnet 4 and the magnetic movable member 2;
It consists of a second spring 7 that always elastically urges the permanent magnet 4 toward the valve seat 1a and that allows the permanent magnet to move in a direction away from the valve seat 1a. The magnetic movable member 2 has a first region d1 where the elastic force of the first spring 3 overcomes the magnetic force acting between it and the permanent magnet 4, and a second region d1 where the magnetic force overcomes the elastic force. area d2 of
It is provided so that it can be moved between. Further, at all times, the magnetic movable member 2 is moved in the first area close to the boundary between the first area d1 and the second area d2 due to the balance between the magnetic force and the elastic force. It is located in In an emergency,
When the excitation coil 5 is excited, it moves the magnetic movable member 2 from the first region d1 to the second region d.
It is provided so as to exert a magnetic force sufficient to drive up to 2.

Here, the valve body 1 and the magnetic movable member 2 are made of soft magnetic material and are integrally formed in a bullet shape as shown in FIGS. 1a and 1b. The valve body 1 integrally formed with the movable member 2 is movably housed in a valve chamber 6a formed in a tubular non-magnetic casing 6. In addition, the first spring 3
Although a coil spring is used in the example,
This is provided in the casing 6 so as to always elastically urge the magnetic movable member 2 in a direction to move it away from the valve seat 1a.

Now, the fluid circuit breaker configured as above is
First, in the open state, which is the standby state, as shown in FIG. It is stabilized at a position within the first region close to the boundary between the first region and the second region due to a spring force acting approximately in proportion to the distance. In this stable position, the elastic force of the spring device 3 slightly overcomes the magnetic force acting between it and the permanent magnet 4, so that the valve body 1 is pulled to the retracted position away from the valve seat 1a. Hold. When a slight driving current is supplied to the excitation coil 5, the valve body 1 is driven to move toward the valve seat 1a together with the movable member 2, as shown in FIG. 2a. When the amount of movement reaches a certain threshold value, that is, when the movable member 2 is driven to move to the second region d2 where the magnetic force exceeds the elastic force, the valve body 1 As shown in FIG. 2b, it is rapidly drawn toward the valve seat 1 together with the movable member 2, closing the flow path. This closed state of the flow path continues to be maintained due to the magnetic force acting between the flow path and the permanent magnet 4 even after the drive current to the excitation coil 5 is cut off. At this time, the valve body 1 closes the valve seat 1a because the magnetic force acting between the magnetic movable member 2 and the permanent magnet 4 increases rapidly in inverse proportion to the square of the distance between them. Once the magnetic movable member 2 crosses the boundary between the first region d1 and the second region d2, it can move very quickly and with a strong force. In addition, when the valve body 1 closes the valve seat 1a, the movable member 2 comes closest to the permanent magnet 4, so the position of the movable member 2 is affected by the strong magnetic force when it approaches. is stabilized, and therefore even high-pressure fluid flows can be reliably blocked. What should be noted here is that
The force that keeps the valve body 1 in the first region d1 is determined by a spring force that is approximately proportional to the distance, and the force that causes the valve body 1 to block the valve seat 1a in the second region d2 is determined by the distance. The magnetic force of the permanent magnet is determined to be inversely proportional to the square of the square, and the magnetic movable member 2 is normally operated at the first position by the balance between the magnetic force of the permanent magnet 4 and the elastic force of the first spring 3. The first region is located close to the boundary between the first region and the second region. Thereby, the valve body 1 can be stabilized in any of the first and second regions d1 and d2 without any particularly critical elements, and the valve body 1 can be stabilized in any of the first and second regions d1 and d2. The transition from the first region d1 to the second region d1 can be smoothly performed, and as a result, reliable operation can be obtained. As a result, the excitation coil 5 can be made compact and simple in structure, consumes low power, and only needs to be triggered for a short period of time. This excitation coil 5
Compared to the drive solenoid in a conventional electromagnetic valve device, the solenoid can be made much simpler and cheaper, and moreover, can be made less prone to failure.

Furthermore, if the movable member 2 is configured to be in a fluid flow path controlled by the valve body 1 and the valve seat 1a as in the embodiment, the movable member 2 may flow in the fluid flow path. The pressure of the fluid causes the first spring 3 to
The flow direction of the fluid is selected so as to resist the elastic force of, that is, the direction of the valve seat 1a, and the elastic force of the first spring 3 and the retracted position of the movable member 2 are appropriately selected. This allows the movable member 2 to move from the first region d1 to the second region d2 even when the pressure difference between the inflow side and the outflow side of the fluid exceeds a predetermined value or when the flow rate of the fluid flowing through the flow path exceeds a predetermined value. It can be driven to move. Therefore, it is possible to configure the system so that the shutoff operation is automatically performed even when there is an abnormal increase in the pressure difference or the flow rate. If such a configuration is added, for example, when a fuel gas pipe is accidentally disconnected, the system can also be activated by the abnormal outflow of gas and automatically shut off the gas. Therefore, when used as a gas circuit breaker, even better safety effects can be obtained. In this case, the movable member 2 does not necessarily have to be configured as shown in the drawings, as long as it is configured to be biased in the direction of the permanent magnet 4 by the pressure of the fluid flowing through the flow path. good.

Note that the drive current to the excitation coil 5 is applied when the movable member 2 moves from the first region d1 to the second region d2.
It is only necessary to supply the driving current for a very short period of time until the motor is driven to move.
Although not shown, it is preferable to use, for example, a timer or a time constant element for control.

By the way, the circuit breaker that has been closed as described above can be easily restored by temporarily removing the permanent magnet 4 or by separating it from the movable member 2. In the example, FIG.
As shown in FIG. 2, once the permanent magnet 4 is manually moved in front of the valve seat 1a against the elastic force of the spring 7 that holds it in place, the valve body 1 is moved as follows. It is pulled together with the movable member 2 by the first spring 3 and returns to its original rear position. Thereafter, by returning the permanent magnet 4 to its original semi-fixed position, it is possible to easily return to the standby state as shown in FIG. 1a. in this way,
The fact that the return operation can be performed easily also greatly contributes to simplifying the inspection of the operation.

FIG. 3 shows an example of how to use the circuit breaker described above, in which the circuit breaker 9 is operated in conjunction with the operation of the gas leak alarm 8.
The gas leak detector 8 includes a gas sensor 8a that detects leakage of reducing gas, that is, fuel gas, by a change in the conductivity of a semiconductor;
The buzzer 8c is connected to a power source 8b via a normally open contact P that closes in response to the sensing output of the sensor a. When gas is detected by the gas sensor 8a, the contact P closes, the buzzer 8c is driven, and an alarm is emitted. At this time, the buzzer 8c
The drive current supplied to the drive terminal is also branched and supplied to the circuit breaker 9 via the timer circuit 9a, whereby the gas is also cut off along with the alarm. In this way, once the gas is cut off, the circuit breaker 9 continues to maintain the cutoff state even after the gas sensor 8a returns to the non-sensing state. After this, if the cause of the gas leak is completely eliminated, the permanent magnet 4 can be moved to restore the original state.

FIG. 4 specifically shows the connection status between the gas leak detector 8 and the circuit breaker 9. During normal operation, that is, when there is no gas leak, the gas sensor 8a is simply maintained in a standby state. Since it consumes only a small amount of current, even if used for a long period of time, the power consumption is small. Further, even if the circuit breaker 9 operates to cut off the gas while the user is away, no power is consumed to maintain the cutoff state, so there is no need to worry even if the user is away for a long time. And circuit breaker 9
As mentioned above, the excitation coil 5, which is the starting device, can be configured very simply, so that the operation is reliable and highly reliable, and maintenance and inspection are also very easy.

In this example, a commercial power source (AC, 100V) is used as the power source 8b, but due to its low power consumption, a battery can also be sufficient.

FIG. 5 shows another example of the use of the circuit breaker, in which a mercury switch 10 whose contacts are closed by vibration or tilting is attached to the circuit breaker 9. By intervening this mercury switch 10 in series between the excitation coil and the power source, it is possible to automatically shut off the gas in the event of an earthquake or the like.

Note that the mercury switch 10 may of course be replaced by another detection switch, and by directly attaching the mercury switch 10 and the circuit breaker 9 to a gas appliance, the gas appliance can be made to have an earthquake-resistant structure. can do.

Although the application example as a gas circuit breaker has been mainly explained above, the fluid circuit breaker according to the present invention is
For example, it can be applied to applications such as shutting off tap water or liquid fuel.

As described above, the fluid circuit breaker according to the present invention has
The difference in properties between the spring force, whose acting force is approximately proportional to the distance, and the magnetic force from a permanent magnet, whose acting force is inversely proportional to the square of the distance, is utilized to make the magnetic movable member always stay in the first position. The first area is located in the first area close to the second area, which eliminates critical elements that would make the operation unstable, ensures the operation, and improves the structure. It is possible to simplify the process, increase reliability, operate reliably without failure even if left inactive for a long period of time, and achieve the effects of low cost. can. Furthermore, the required drive current for activation can be reduced, and moreover, it can be activated by trigger drive. Further, since the operating speed can be increased, it is possible to easily link the sensor with a gas leak detector, an earthquake sensor, etc., and to quickly respond to the operation of the sensor, etc.

[Brief explanation of the drawing]

Figures 1a and 1b show the fluid circuit breaker according to the present invention in an open state, where a is a sectional view and b is a cross-sectional view.
is a sectional view taken along line A-A in figure a, figure 2 a, b,
c is a sectional view showing each state of the fluid circuit breaker, FIG. 3 is a circuit diagram showing an example of the use of the gas circuit breaker, FIG. 4 is a perspective view showing its usage state, and FIG. 5 is a diagram showing other uses. It is a sectional view showing an example. 1... Valve body, 2... Magnetic movable member, 3... First
spring, 4... permanent magnet, 5... excitation coil, 6
……casing.

Claims (1)

[Claims] 1. A magnetic movable member provided integrally with a valve body within a valve chamber formed in a non-magnetic casing disposed in the horizontal direction, and a magnetic movable member that is elastically attached in a direction in which the valve body moves away from a valve seat. a first spring that is biased;
an annular permanent magnet disposed outside the casing and exerting a magnetic force on the magnetic movable member to bias the valve body toward the valve seat; an excitation coil disposed at an intermediate position between the two, and a second magnet configured to always elastically bias the permanent magnet toward the valve seat and to allow the permanent magnet to move in a direction away from the valve seat. The magnetic movable member includes a first region where the elastic force of the first spring overcomes the magnetic force acting between it and the permanent magnet, and a second region where the magnetic force overcomes the elastic force. The magnetic movable member is provided so as to be movable between the first region and the second region at all times due to the balance between the magnetic force and the elastic force. The excitation coil is located within the first region, and when the excitation coil is excited in an emergency, the excitation coil connects the first region to the magnetic movable member.
A fluid breaker, characterized in that it is provided to exert a magnetic force sufficient to drive the fluid from the region to the second region.