JPS6342221Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a self-holding solenoid valve in which the valve body is held open and closed by an excitation coil and a permanent magnet. This makes it possible to detect and ensure safety.

Emergency solenoid valves are known that operate a solenoid valve using the detection signal to cut off the supply of gas, etc. when a gas leak or earthquake is detected. It is desirable to be able to check from the outside whether the door is correctly closed. In that case, attempts have been made to incorporate a micro switch to detect the movement of the movable core for driving the valve body, but in an atmosphere of flammable gas there is a risk of ignition from sparks from the contact. It is safe to use reed switches whose contacts are sealed. Usually, in order to detect a position using a reed switch, a permanent magnet is arranged in a movable manner, and the reed switch is opened and closed by moving the permanent magnet toward and away from the reed switch. However, with this method, a special permanent magnet must be installed, and in consideration of variations in the sensitivity of the reed switch,
There are drawbacks such as the need to accurately adjust the relative positions of the reed switch and the permanent magnet in advance.

The present invention solves these problems by effectively utilizing the magnetic force of the permanent magnet of the self-holding solenoid valve without requiring a special permanent magnet for driving the reed switch, and without making any adjustments. The purpose is to accurately detect the open/closed state of the valve body from the outside. to this end,
The basic structure of the present invention is that an excitation coil and a permanent magnet are arranged adjacent to each other inside a magnetic frame made of a magnetic material, and a movable iron core that extends to the side of the permanent magnet is built into the central hole of the excitation coil. In a self-holding electromagnetic valve in which the movable iron core drives a valve body via a valve stem, the magnetic force of the permanent magnet is used to drive a reed switch.

That is, the movable core is provided with a magnetic pole plate that drives the reed switch, and the reed switch is arranged between the magnetic frame surrounding the permanent magnet and the excitation coil and the magnetic pole plate so that the reed pieces are approximately parallel to the movable core. When the reed switch is installed and the magnetic pole plate is separated from the permanent magnet, the contact part of the reed switch is located between the magnetic plate and the magnetic frame, but when the magnetic pole plate is moved toward the permanent magnet, the reed switch A configuration is adopted in which the magnetic pole plate is positioned between the contact portion of the magnetic frame and the magnetic frame. When the valve body is open, the excitation coil is not energized, and the movable core is attracted to the fixed core by the magnetic force of the permanent magnet, creating a magnetic loop of "permanent magnet - movable core - fixed core - magnetic frame - permanent magnet". is formed, and the valve body is self-retained in the open state. At this time, since the magnetic pole plate is located on the same side as the magnetic frame with respect to the contacts of the reed switch, the contacts of the reed switch are in an open state.

When a detection signal such as an earthquake or gas leak is input and the excitation coil is energized, the magnetic flux of the permanent magnet is canceled by the magnetic flux, so the valve body closes due to the spring pressure of the closing spring, and the movable iron core connects to the fixed iron core. At the same time, the magnetic pole plate is separated from the permanent magnet and passes through the contact position of the reed switch. In other words, since the magnetic pole plate is located on the opposite side of the reed switch contact point from the magnetic frame, the magnetic flux of the permanent magnet flows through the magnetic loop of "permanent magnet - movable iron core - magnetic pole plate - reed switch contact point - magnetic frame - permanent magnet". The contact of the reed switch is closed, and the closure of the valve body is detected externally.

In this way, when the movable iron core is attracted to the fixed iron core by a permanent magnet, the permanent magnet is used exclusively for opening the valve, and when the movable iron core is separated from the fixed iron core and the valve is closed, the permanent magnet is used exclusively for opening the reed switch. Used for contact closure. Furthermore, when the movable iron core is attracted to the fixed iron core and the magnetic pole plate is located near the permanent magnet, the magnetic pole plate and magnetic frame are located on the same side of the reed switch contact, so the reed switch can be operated reliably. The contact becomes open. On the other hand, in the closed state where the movable iron core is separated from the fixed iron core, the magnetic pole plate and the magnetic frame are located on the opposite side to the contact point of the reed switch. That is, since the contact of the reed switch is sandwiched between the magnetic pole plate and the magnetic frame, the magnetic flux reliably passes through the contact of the reed switch, and the contact is closed. Furthermore, since the bridging magnetic body has a magnetic pole face facing the movable core and a contact face with the permanent magnet, the shape of the permanent magnet can be freely selected. As described above, according to the present invention, the permanent magnet for self-holding of the valve body can also be used to drive the reed switch without providing a special permanent magnet for driving the reed switch.
Furthermore, when the reed switch is closed and opened, the magnetic pole plate moves to completely opposite positions relative to the contacts of the reed switch, so the contacts can be opened and closed reliably, and the problem of variations in sensitivity of the reed switch is no longer an issue.

Next, an implementation of the self-holding solenoid valve according to the present invention will be described. FIG. 1 is a longitudinal cross-sectional view showing the overall configuration of a self-holding electromagnetic valve, with the left half of the figure showing the valve in a closed state and the right half showing the valve in an open state. B is the main body of the solenoid valve,
An inlet 1 on the left side and an outlet 2 on the right side communicate with each other through a valve hole 3 and a valve chamber 4. The valve body 5 in the valve chamber 4 is closed by being pressed against the valve seat 7 at the periphery of the valve hole 3 by a closing spring 6. Note that the base end of the closing spring 6 is supported by the lower cover 8. The valve body 5 is connected to a movable iron core 10 via a valve stem 9.

A self-holding solenoid S is mounted on the main body B via a mounting plate 11. The self-holding solenoid S is arranged with an excitation coil 13 and a permanent magnet 14 stacked on top of each other in a frame 12 made of a magnetic material, and a movable solenoid that extends to the side of the permanent magnet 14 is placed in a hole of the excitation coil 13. Iron core 10 is inserted. A fixed iron core 15 is built in and fixed to the lower end of the hole of the excitation coil 13, and the movable iron core 10 is attracted to and separated from the fixed iron core 15 within the excitation coil 13. A magnetic pole plate 16 made of a magnetic material is fixed to the movable iron core 10 at a position outside the permanent magnet 14 . As shown in the left half of the figure, when the valve body 5 is closed and the movable iron core 10 and the magnetic pole plate 16 are raised, the contact 17 is positioned between the outer end of the magnetic pole plate 16 and the magnetic frame 12. , reed switch 18 are provided. As shown in the right half of the figure, the movable core 10 is connected to the fixed core 15.
When the valve body 5 is opened, the magnetic pole plate 1
6 moves to a position below the contact 17 of the reed switch, that is, to a position near the magnetic frame 12.

Self-holding solenoid S and reed switch 18
are built into the casing 19, but an operating rod 20 extending from the movable core 10 projects outside the casing 19, and is provided with an operating button 21 at the tip of the protruding portion. A cap 22 is attached to the casing 19 to cover the operation button 20 to prevent it from being accidentally operated. Note that the casing 19 and the operating rod 20 are sealed with a bellow ram 23, the casing 19 and the main body B are sealed with a packing 24, the body B and the valve stem 9 are sealed with a bellow ram 25, and the main body B and the lower cover 8 are sealed.
The spaces between the two are sealed with sealing pads 26, respectively.

Next, the operation will be explained. To open the valve body from the closed state as shown in the left half of the figure, remove the cap 22,
Push down the operation button 21 against the closing spring 6,
The movable iron core 10 is attracted to the fixed iron core 15. That is, when the movable iron core 10 is moved toward the fixed iron core 15 side, the magnetic flux of the permanent magnet 14 passes through the closed loop of "permanent magnet 14 - movable iron core 10 - fixed iron core 15 - magnetic frame 12 - permanent magnet 14", so the movable iron core 1
0 is attracted to the fixed iron core 15, and as shown in the right half of the figure, the valve body 5 resists the closing spring 6,
The valve is held open. At this time, the magnetic pole plate 16 is
Since it is located below the contact 17 of the reed switch, no magnetic flux passes through the contact 17, and therefore the reed switch contact 17 is in an open state. That is, no detection signal is generated from the reed switch 18, and it is detected externally that the valve body 5 is open.

The valve body 5 opens and the controlled fluid such as gas enters the inlet 1.
When the excitation coil 13 is energized by a detection signal such as an earthquake or a gas leak while the magnetic flux is flowing from the permanent magnet 14 to the exit 2, the magnetic flux of the permanent magnet 14 is transferred to the excitation coil 13.
Since the excitation coil 13 is excited in a direction that is canceled by the magnetic flux generated by the magnetic flux, the magnetic attraction force between the movable iron core 10 and the fixed iron core 15 due to the permanent magnet is weakened. Therefore, the valve body 5 and the movable core 10 are pushed up by the spring force of the closing spring 6, and the valve body 5 contacts the valve seat 7, thereby closing the valve. At this time, the magnetic pole plate 16
is also pushed up and moved above the position of the reed switch contact 17, and the reed switch contact 17 is located between the magnetic pole plate 16 and the upper end of the magnetic frame 12 as shown in the left half of the figure. In this state, the magnetic flux caused by the permanent magnet 14 is
The magnetic flux at this time closes the reed switch contact 17 and maintains it in the closed state because it passes through the closed loop of "-movable iron core 10 - magnetic pole plate 16 - reed switch contact 17 - magnetic frame 12 - permanent magnet 14" . The signal when the reed switch contact closes notifies the outside that the valve body 5 is closed, and using this signal, the closed state of the valve can be confirmed by lighting a lamp or sounding a buzzer.

Next, when opening the valve body to allow the controlled fluid to pass through again, remove the cap 22 as described above, press down the operation button 21, and move the movable iron core 10 to the permanent magnet 14.
It is attracted to the fixed iron core 15 by the magnetic force of.

FIGS. 2 and 3 are diagrams showing the magnetic path configuration in the reed switch 18 when the valve is open, that is, when the magnetic pole plate 16 is lowered. The movable core 10 is the fixed core 1
5, most of the magnetic flux from the permanent magnet flows to the magnetic pole plate 16 side because it passes through the closed loop of "permanent magnet 14 - movable iron core 10 - fixed iron core 15 - magnetic frame 12 - permanent magnet 14". The magnetic flux is extremely small, and the magnetic pole plate 16 is located on the same side of the reed switch contact 17 as the magnetic frame 12. Therefore, as shown in FIG. 3, the magnetic flux does not pass through the contact 17, and even if a small amount of leakage magnetic flux passes through the lower lead piece 27 of the reed switch,
Since the two contacts in the contact portion 17 have the same polarity, no magnetic attraction force is generated, and therefore there is no possibility that a malfunction such as the contact 17 closing occurs.
Note that leakage magnetic flux also passes between the magnetic pole plate 16 and the magnetic frame 12, and it appears that almost no magnetic flux reaches the reed switch reed piece.

When the movable iron core 10 rises and the valve is closed, the magnetic pole plate 16 is positioned above the contact 17 of the reed switch, that is, on the opposite side of the magnetic frame 12 with respect to the contact 17. Then, as shown in FIG. 5, the magnetic flux due to the permanent magnet 14 becomes
It passes through a closed loop of the movable iron core 10 - the magnetic pole plate 16 - the upper lead piece 28 of the reed switch - the lower lead piece 27 - the magnetic frame 12 - the permanent magnet 14.
Therefore, as shown in FIG. 5, if the lower end of the upper lead piece 28 becomes the S pole, the lower lead piece 2
Since the upper ends of the contacts 7 serve as opposite north poles, a magnetic attraction force is generated between the two opposing contacts in the contacts 17, and the contacts are closed. Moreover, since the movable iron core 10 is separated from the fixed iron core 15, the permanent magnet 14
Most of the magnetic flux passes through the contact 17, and almost all of the magnetic force of the permanent magnet is transferred to the contact 17.
It can be used to close the contacts, ensuring reliable contact closure. Note that in order to reduce leakage magnetic flux between the movable core 10 and the fixed core 15, at least the portion of the valve stem 9 between the movable core 10 and the fixed core 15 is preferably made of a non-magnetic material. FIG. 6 is a cross-sectional view taken along the line -' in FIG. 2, in which a rectangular parallelepiped block is used as the permanent magnet 14, and a magnetic body is provided with a magnetic pole surface 29 facing the movable iron core 10 and a contact surface 30 between the permanent magnet 14. A bridging member 31 made of . Therefore, magnetic flux passes between the permanent magnet 14 and the movable iron core 10 via this bridging magnetic body 31, but since the bridging magnetic body can be easily manufactured into any shape compared to permanent magnets,
The permanent magnet 14 can have a simple shape.
FIG. 7 shows yet another embodiment, in which the bridging magnetic material is 31a
This is an example in which the magnet is divided into two parts, 31b and 31b, and a non-magnetic material 32 such as plastic is interposed between them, so that the left permanent magnet and the right permanent magnet have independent magnetic paths.

As described above, according to the present invention, when the magnetic force of the permanent magnet in the self-holding solenoid valve is not used to drive the valve body, the contact part of the reed switch is interposed in the middle of the magnetic loop formed by the permanent magnet. A permanent magnet, a movable iron core, a magnetic pole plate, a reed switch, and a magnetic frame are arranged in the . Therefore, the permanent magnet of the self-holding solenoid valve can also be used to drive the reed switch, and the reed switch operates accurately and there is no risk of malfunction.
There is no need for adjustments due to variations in reed switch sensitivity. Moreover, since the magnetic bridging body is interposed between the permanent magnet and the movable iron core, the permanent magnet can be made into a simple shape.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing the overall structure of the self-holding solenoid valve according to the present invention, Figs. 2 and 3 are views showing the magnetic path structure of the reed switch section when the valve is open, and Figs. 4 and 5. This figure shows the magnetic path configuration of the reed switch when the valve is closed, and FIGS. 6 and 7 are sectional views showing different embodiments of the magnetic bridging body. In the figure, S is a self-holding solenoid, 5 is a valve body, 9 is a valve stem, 10 is a movable core, 12 is a magnetic frame, 13 is an exciting coil, 14 is a permanent magnet, 1
5 is a fixed iron core, 16 is a magnetic pole plate, 17 is a contact (part),
18 is a reed switch, 27 and 28 are reed pieces, and 31, 31a, and 31b are magnetic bridge members.

Claims (1)

[Claims for Utility Model Registration] An excitation coil and a permanent magnet are arranged adjacent to each other inside a magnetic frame made of a magnetic material, and a movable iron core extending to the side of the permanent magnet is built into the central hole of the excitation coil, In the self-holding solenoid valve in which the movable core drives the valve body via the valve stem, a permanent magnet is provided on the inner surface of the magnetic frame, and a contact surface between the magnetic pole face facing the movable core and the permanent magnet is provided. The movable core is provided with a magnetic pole plate that drives the reed switch, and when the movable core is separated from the fixed core, the magnetic frame surrounding the permanent magnet and the excitation coil is connected to the magnetic pole plate. The contact section is located between them, and when the movable core is attracted to the fixed core, the magnetic pole plate is positioned closer to the permanent magnet than the contact section, and the lead pieces are approximately parallel to the movable core. A self-holding solenoid valve comprising the reed switch.