JPS6244152B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for shutting off fluids such as fuel gas, and in particular, it is always open and does not obstruct the flow of fluid, but if any abnormality occurs, it is immediately closed. The present invention relates to a fluid breaker suitable for use in reliably blocking fluid flow.

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. Therefore, fluid circuit breakers used for such purposes are required to meet stricter conditions than ordinary valve devices. For example, first of all, this type of fluid circuit breaker not only consumes no power when on standby, but also can be driven with a small amount of power. must be maintained regardless of the presence or absence of That is, it must be possible to maintain the open or closed state without consuming any power, and to move between the open and closed states easily and reliably with a small amount of power. This is extremely important in order to prevent normal operation from becoming impossible even if an accident such as a power outage occurs.

Furthermore, fluid circuit breakers used in the above-mentioned applications are not designed to be operated on a daily basis, and are left in an inoperative standby state for long periods of time. , even if a failure were to occur, it would be extremely difficult to detect. Therefore, in this type of fluid circuit breaker, the structure is simplified as much as possible to eliminate components that may cause failure, and even if it is left inactive for a long period of time, when it is activated, It must be able to operate reliably and quickly, and must have sufficiently high reliability to prevent failures in the unlikely event that it occurs.

By the way, if we consider the conventional fluid circuit breakers that are thought to have been developed in view of the above background, we find that the one shown in Figure 1 is already publicly known (Utility Model Publication No. 52-35533). Publication No.). In this valve chamber 1b formed in a non-magnetic casing 1a, a magnetically induced valve body 1c which is movable within the valve chamber 1b is provided.
Two permanent magnets 1d and 1e are provided to remotely attract magnetically from the outside of the casing 1a in opposite directions. Here, the valve body 1c is remotely attracted by one permanent magnet 1d, and the other permanent magnet 1e is used to resist this attraction force to attract the valve body 1c to a position away from the valve seat 1f. This keeps the valve open. Then, a driving current is applied to the excitation coil 1g provided on the outside of the casing 1a, and the valve body 1c is magnetically attracted to the point where the magnetic attraction force of one permanent magnet 1d becomes stronger than that of the other permanent magnet 1e. It is becoming more and more popular. The magnetically attracted position is held by the one permanent magnet 1d. This device uses the magnetic force of remote attraction from permanent magnets.
At first glance, it gives the illusion that it is very cleverly constructed, but in reality, the valve body 1c is subjected to the magnetic remote attraction forces of the two permanent magnets 1d and 1e. In addition, it is difficult to stabilize the fluid under the pressure of the fluid, and in particular, the magnetic force of the permanent magnets 1d and 1e and the setting of their positions are very sensitive elements, and it is difficult to adjust them to ensure reliable operation. It was extremely difficult. Furthermore, in connection with this, variations in products tend to occur, making it impossible to provide high reliability. Therefore, it has to be said that the conventional device as shown in FIG. 1 is extremely unsuitable for practical use as a product.

The present invention has been made in view of the above-mentioned drawbacks in the prior art, and its purpose is to avoid the above-mentioned critical elements, to be easily constructed, and to be able to operate under the action of fluid pressure. It is an object of the present invention to provide a fluid breaker that can operate reliably even when there is a problem, has excellent production suitability when commercialized, and is highly reliable.

According to the knowledge of the inventor of the present application, when a fixed magnetic member and a relatively small movable magnetic member are placed in a magnetic field formed by a permanent magnet and magnetized, the movable magnetic member separates from the fixed magnetic member. If they are even slightly apart, the movable magnetic member will be attracted to the permanent magnet. However, when the movable magnetic member is in direct contact with the fixed magnetic member, the movable magnetic member receives an attractive force that tends to move toward the permanent magnet, but the above-mentioned force between the movable magnetic member and the fixed magnetic member Both are attracted by the induced magnetic attraction force formed by the permanent magnet, and even if the permanent magnet is brought closer to the movable magnetic member to strengthen the magnetic attraction force to the movable magnetic member, the induced magnetic attraction force will also be strengthened. Therefore, the movable magnetic member does not separate from the fixed magnetic member. However, if a magnetic force with a polarity opposite to that of the permanent magnet is applied to the fixed magnetic member under this condition, the induced magnetic attraction force between the movable magnetic member and the fixed magnetic member due to the permanent magnet is significantly weakened or canceled. As a result, the movable magnetic member is separated from the fixed magnetic member and attracted to the permanent magnet.

The present invention was made based on the above knowledge,
In the fluid circuit breaker according to the present invention, a fixed magnetic member is disposed in a valve chamber formed in a non-magnetic casing arranged substantially horizontally, in front of a valve seat in this valve chamber and at a position away from the valve seat. At the same time, a magnetic floating valve body is provided that is movable between the valve seat in the valve chamber and the end of the fixed magnetic member, and magnetic attraction is provided to bias the magnetic floating valve body in a direction to seat the magnetic floating valve body on the valve seat. An annular permanent magnet that exerts a force is disposed outside the casing at a position where the magnetic floating valve body and the end of the fixed magnetic member are magnetized by magnetic induction, A reset coil is disposed on the outer periphery of the casing, and the magnetic floating valve element is normally moved away from the valve seat and brought into contact with the end surface of the fixed magnetic member, and the permanent magnet resets the magnetic floating valve. While receiving an attractive force directed toward the valve seat, the body maintains a state of being attracted to the fixed magnetic member by the induced magnetic attraction force of the permanent magnet, and in the event of an abnormality, the reset coil is configured to change the polarity of the permanent magnet. An energizing means is provided for generating a magnetic field of opposite polarity, and the opposite polarity sufficiently weakens or cancels the induced magnetic attraction force, so that the magnetic floating valve body is caused to be attracted by the attraction force of the permanent magnet. The valve seat is spaced apart from the fixed magnetic member and closes the valve seat.

Embodiments of the fluid circuit breaker according to the present invention will be described below with reference to the accompanying drawings.

FIG. 2 shows a typical embodiment of the fluid circuit breaker 2 according to the present invention. In the one shown in FIG. 2, a valve chamber 3a is formed in a non-magnetic casing 3. Then, in this valve chamber 3a, the valve chamber 3
A fixed magnetic member 4 is provided in front of the valve seat 3b (to the right in the figure) at a position away from the valve seat, and the valve seat 3b in the valve chamber 3a and the end 4a of the fixed magnetic member 4 are provided. A spherical magnetic floating valve body 5 is provided which is movable between the valve body and the valve body. Further, an annular permanent magnet 6 is provided at a position surrounding the valve seat 3b on the outside of the casing 3 so as to exert a magnetic attraction force that urges the magnetic floating valve body 5 in a direction to seat the valve seat 3b. . This permanent magnet 6 is attached to the casing 3
The permanent magnet 6 is normally biased toward the outer circumferential position of the valve seat 3b by a coil spring 8 provided on the outer circumference of the valve seat 3b, and in the case of a reset described later, the permanent magnet 6 compresses the coil spring 8 while moving the fixed magnetic member. 4
It is possible to move up to the outer periphery of the Further, a reset coil 7 is provided on the outer periphery of the fixed magnetic member 4 on the outside of the casing 3, and a constant current is applied to this reset coil in response to a detection signal from a gas leak detector or the like (not shown). This current causes the reset coil 7 to form a magnetic field with a polarity opposite to that of the permanent magnet 6. A micro switch 9 is provided on the opposite side of the coil spring 8 across the permanent magnet 6. This micro switch 9 is connected to a gas leak detector etc. as described above, and the contact point of the micro switch 9 is connected to the permanent magnet 6. When the permanent magnet 6 compresses the coil spring 8 and is moved toward the fixed magnetic member 4, the contact point of the micro switch 9 is actuated, and the contact point of the micro switch 9 is activated. Can be used to provide a reset signal.

The above-mentioned magnetic floating valve body 5 is seated on the valve seat 3b by the magnetic attraction force of the permanent magnet 6 to shut off fluid, and in a first stable state, and as shown in FIG. A second stable state can be achieved in which the fluid is magnetically attracted and forms a fluid flow path within the casing 3.

Here, the magnetic coupling force that maintains the magnetic floating valve body 5 in the second stable state is based on the magnetic force of the permanent magnet. The permanent magnet 6 is required to have a relatively strong magnetic force in order to magnetically attract the floating valve body 5, and due to the magnetic induction effect of this strong magnetic force, the permanent magnet This produces magnetization between the member 4 and the member 4 for mutual magnetic attraction.

In this way, when the valve body 5 and the fixed magnetic member 4 are made to magnetically attract each other by magnetic induction from the permanent magnet 6, the magnetic attraction force increases as the magnetic force of the permanent magnet 6 becomes stronger. Become stronger. Therefore, even if the magnetic force of the permanent magnet 6 is strengthened to strongly magnetically attract the valve body 5 toward the valve seat 3b, the magnetic attraction force also increases as the magnetic attraction force increases. The above-mentioned second stable state is not broken, but rather can be moved in a more stable direction. Moreover, as a result, the magnetic force of the permanent magnet 6 can be greatly increased, so that the first stable state in which the valve body 5 is seated on the valve seat 3b can be further stabilized.

The reset coil 7 is used to release the magnetically attracted state between the valve body 5 and the fixed magnetic member 4 when energized. At the same time, a current is supplied that generates a magnetic field that significantly weakens or cancels the magnetic attraction between the valve body 5 and the fixed magnetic member 4 caused by the magnetic induction. Such current may be a direct current, or it may be a normal commercial alternating current since it is sufficient to momentarily release the magnetic attraction state. In any case, the power supply to the reset coil 7 only needs to temporarily release the magnetic attraction state, and does not need to be sustained.

By energizing the reset coil 7 as described above,
When the magnetic attraction between the valve body 5 and the fixed magnetic member 4 is significantly weakened or canceled, the valve body 5 is pulled away from the fixed magnetic member 4 because the attraction force of the permanent magnet 6 is originally acting on the valve body 5. Permanent magnet 6
is moved toward the center of the casing 1, and is seated on the valve seat 3b, thereby blocking the flow path within the casing 1.

Now, FIG. 3 a, b, c, d, and e show each operating state when the above-mentioned fluid circuit breaker 2 is used. First, in the state shown in FIG. 5 and the fixed magnetic member 4 overcome the magnetic attraction force of the permanent magnet 6 and are magnetically attracted to each other. As shown in FIG. , 4b... are formed. Therefore, in this state, the circuit breaker 2 is open and fluid such as gas can flow approximately along the arrow.

In this open state, the reset coil 7
When an alternating current is supplied to the coil 7, a magnetic field with a polarity opposite to that of the permanent magnet is momentarily generated, which causes the valve body 5 and the fixed magnetic member 4 to
The magnetically attracted state between the valve body and the valve body is no longer maintained, and the valve body is magnetically attracted by the permanent magnet 6 and seats on the valve seat 3b, as shown in FIG. 3B, thereby closing the flow path.
Of course, this closed state is maintained even after the drive current to the reset coil 7 is cut off.

FIG. 3c shows the case where the closed state shown in FIG. 3b is returned to the open state shown in FIG. When the valve body 5 is forcibly moved toward the fixed magnetic member 4 side, the valve body 5 moves toward the fixed magnetic member 4 side together with the permanent magnet 6, and the end portion 4a of the fixed magnetic member 4 is moved toward the fixed magnetic member 4 side.
and is magnetically attracted there. Once the valve body 5 is magnetically attracted to the fixed magnetic member 4, the magnetically attracted state is maintained even if the permanent magnet 6 is returned to its original normal position as shown in FIG. That is,
The return operation is easily completed by simply moving the permanent magnet 6.

After the return operation, as shown in FIG. 3d, the permanent magnet 6 is pressed against the valve seat 3b, thereby allowing the microswitch 9 to return to its original non-operating position. Therefore, after the reset operation, for example, the reset coil 7
It is also possible to easily provide a reset signal to a gas detector or the like that controls the drive current to the gas detector.

4a and 4b show another embodiment of the present invention, and only the differences from the previous embodiment will be described. Here, the fixed magnetic member 4 is formed in a tubular shape, and this It is inserted along the inner surface of the casing 3. In this case, in order to prevent the flow path from being blocked when the valve body 5 is magnetically attracted to the end 4a, a suitable notch 4c is formed in the end 4a.

Further, the fixed magnetic member 4 can also be formed in a lattice shape, as shown in FIGS. 5a and 5b.

Furthermore, as shown in FIGS. 6a and 6b, the fixed magnetic member 4 may be formed in a part of the casing 3. In this case, the casing 3 is the valve seat 3
While the b side is formed of a non-magnetic material, the portion corresponding to the fixed magnetic member 4 is formed of a magnetic material.

FIG. 7 shows yet another embodiment, in which a spring 10 is provided that constantly presses the magnetic floating valve body 5 toward the end of the fixed magnetic member 4. . This spring 1
0 is provided to assist the valve body 5 in transitioning from the first stable state to the second stable state, thereby facilitating the reset operation under strong fluid flow pressure. It can be made more stable. For this reason, it is appropriate that the spring constant of the spring 10 is set so as to substantially cancel out the flow pressure of the fluid that the valve body 5 receives. Further, the spring constant must be set within a range where at least the first stable state and the second stable state can exist together. The above spring 10
is provided on the valve seat 3b side in the embodiment, but it can also be provided on the fixed magnetic member 4 side.

FIG. 8 shows yet another embodiment,
Here, in order to obtain the second stable state or to make the state even more stable, a second annular permanent magnet 11 is fixedly provided on the fixed magnetic member 4 side. This second permanent magnet 11 is attached to the fixed magnetic member 4 in cooperation with the permanent magnet 6.
provides the necessary magnetization state to maintain the stable state of the magnet more stably.

The embodiments shown in FIGS. 7 and 8 are particularly effective in cases where fluid pressure is particularly strong, such as city gas.

In both embodiments, the valve body 5 and the fixed magnetic member 4 are made of soft magnetic material.

As described above, the fluid circuit breaker according to the present invention has
While the valve body and the fixed magnetic member are attracted to each other by the induced magnetic attraction force of the permanent magnet provided on the valve seat side, the valve body is attracted to the magnetic member by the permanent magnet. Therefore, it is only necessary to instantaneously flow through the reset coil a magnetic field generating current sufficient to weaken the above-mentioned induced magnetic attraction force, so the coil is small and only a small amount of current is required, and it is not possible to There is no critical element for the operation of the valve body, and an extremely reliable fluid breaker that operates reliably can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a conventional fluid breaker, FIG. 2 is a sectional view showing an embodiment of a fluid breaker according to the present invention, and FIGS. Cross-sectional views showing each operating state when using the fluid circuit breaker, Figure e is A-A in Figure a.
4a is a sectional view showing another embodiment; FIG. 4b is a sectional view taken along line B-B in FIG. 5a; FIG. 6A is a sectional view showing still another embodiment, and FIG. 6B is a sectional view taken along D--C in FIG. 6A.
D sectional view, FIG. 7, and FIG. 8 are sectional views showing still further embodiments. 2...Fluid circuit breaker, 3...Non-magnetic casing,
4...Fixed magnetic member, 5...Magnetic floating valve body, 6...
...Permanent magnet, 7...Reset coil, 3a...Valve chamber, 3b...Valve seat.

Claims (1)

[Claims] 1 In a valve chamber formed in a non-magnetic casing disposed approximately horizontally, a fixed magnetic member is disposed in front of a valve seat in this valve chamber at a position away from the valve seat, and a fixed magnetic member is disposed in a position away from the valve seat in the valve chamber, and A permanent annular valve body is provided with a magnetic floating valve body that is movable between the seat and the end of the fixed magnetic member, and that exerts a magnetic attraction force that urges the magnetic floating valve body in a direction to seat the magnetic floating valve body on the valve seat. A magnet is disposed outside the casing at a position where the magnetic floating valve body and the end of the fixed magnetic member are magnetized by magnetic induction, and a reset coil is provided on the outer periphery of the casing outside the fixed magnetic member. The magnetic floating valve body is always separated from the valve seat and brought into contact with the end face of the fixed magnetic member, and the magnetic floating valve body is directed toward the valve seat side by the permanent magnet. While receiving an attractive force, the magnet remains attracted to the fixed magnetic member by the induced magnetic attraction force of the permanent magnet, and in the event of an abnormality, generates a magnetic field in the reset coil with a polarity opposite to that of the permanent magnet. An energizing means is provided, and the opposite polarity sufficiently weakens or cancels the induced magnetic attraction force, whereby the magnetic floating valve body is separated from the fixed magnetic member by the attraction force of the permanent magnet, and the valve body is separated from the fixed magnetic member. A fluid circuit breaker characterized in that it is configured to cover a seat.