JP5448920B2 - Gate open / close sensor and gate open / close monitoring system - Google Patents

Description

  The present invention relates to a gate opening / closing sensor that detects opening / closing of a gate such as a sluice or lock gate, and a gate opening / closing monitoring system that monitors an opening / closing state of a gate based on a light output from the gate opening / closing sensor.

  In the field of gate opening and closing monitoring of locks, sluices, etc. installed in rivers managed by the country, various problems such as cost and local cooperation are indispensable for ITV cameras and visual monitoring. There is. Therefore, as a technique for monitoring the open / close state of the water channel gate, a method using an optical contact has been proposed (for example, Patent Document 1). Here, the optical contact is a general term for an element having a configuration for controlling light emitted to the optical fiber according to the open / closed state of the gate (for example, controlling on / off of light output).

Patent Document 1 discloses a gate open / close monitoring system using a Faraday element type optical contact as an example. Specifically, as shown in FIG. 4, an optical contact 1 is provided at one end of the optical fiber 2, this optical contact 1 is installed on a support member (not shown) such as a support near the gate 5, and the permanent magnet 3 is attached. A gate open / close monitoring system is built at the gate 5.
In such a gate open / close monitoring system, the magnetic field applied to the optical contact 1 by the magnet 3 increases when the magnet 3 approaches the optical contact 1 (gate closed state) and when the magnet 3 moves away (gate open state). Get smaller. The optical contact 1 controls on / off of light emitted to the optical fiber 1 according to the open / closed state of the gate, utilizing the property of the Faraday element that rotates the polarization plane of light according to the strength of the magnetic field. . That is, in the gate open / close monitoring system, the open / close state of the gate is determined based on the presence or absence of light emitted from the optical contact 1 to the optical fiber 2.

Japanese Patent No. 3643738

By the way, in the gate open / close monitoring system described in Patent Document 1, the permanent magnet 3 installed on the gate 5 moving up and down is such that the strength of the magnetic field applied to the optical contact 1 corresponds to the open / closed state of the gate. In addition, it is necessary to operate normally within the influence range of the magnetic force (the range in which the magnetic field is applied to the optical contact 1 by the magnet 3).
However, there may be a problem that normal operation is not possible within the influence range of the magnetic force due to aging of facilities such as support members and gates or the influence of wind and rain with the passage of time of operation. For example, the strength of the magnetic field applied to the Faraday element fluctuates even when the relative distance from the magnet 3 is shifted by several centimeters. Therefore, the rattling of the gate 5 is erroneously regarded as a change in the open / close state of the gate 5. May be judged. Therefore, there is a demand for a gate opening / closing monitoring system for solving such a problem.

  An object of the present invention is to provide a technique capable of accurately monitoring the open / close state of a gate in a gate open / close sensor and a gate open / close monitoring system using an optical contact.

The invention described in claim 1 is made in order to achieve the above object, and an optical contact that controls light emitted to an optical fiber according to the strength of a magnetic field;
A magnetic field generator for applying a constant magnetic field to the optical contact;
A magnetic field shielding unit that shields the magnetic field applied to the optical contact by the magnetic field generation unit according to an open / closed state of a gate such as a sluice or a lock gate,
The gate contact sensor is characterized in that the optical contact and the magnetic field generator are installed so as to maintain a constant separation distance regardless of the gate open / close state.

According to a second aspect of the present invention, in the gate opening / closing sensor according to the first aspect, the optical contact is a Faraday element that rotates the polarization plane of the light emitted from the light source in accordance with the strength of the magnetic field.
And a polarizer capable of blocking light that has passed through the Faraday element.

  The invention according to claim 3 is the gate opening / closing sensor according to claim 1 or 2, wherein the magnetic field shielding part is a plate-like member capable of physically separating the optical contact and the magnetic field generation part, The magnetic field applied to the optical contact is shielded by moving in conjunction with opening and closing of the gate.

  According to a fourth aspect of the present invention, in the gate opening / closing sensor according to any one of the first to third aspects, the magnetic field shielding portion is made of a magnetic material.

The invention according to claim 5 is a gate opening / closing sensor according to any one of claims 1 to 4,
An open / close monitoring system comprising: an open / close detection device that detects the open / closed state of the gate by receiving light emitted from the gate open / close sensor.

  According to a sixth aspect of the present invention, in the gate opening / closing monitoring system according to the fifth aspect, the optical contact and the magnetic field generator are fixed to the same structure.

  According to the gate opening / closing sensor and the gate opening / closing monitoring system according to the present invention, it is possible to accurately monitor the opening / closing state of the gate and to improve the reliability irrespective of the passage of the operation year and month.

It is explanatory drawing which shows the outline | summary of the gate opening / closing sensor which concerns on this invention. It is explanatory drawing which shows an example of an internal structure of a Faraday element type optical contact. It is explanatory drawing which shows an example of the concrete mounting aspect of a gate opening / closing sensor. It is explanatory drawing which shows the outline | summary of the conventional gate opening / closing sensor.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an explanatory diagram showing an outline of a gate opening / closing sensor according to the present invention. In FIG. 1, a sluice 100 of a pull-up gate is shown as an example. That is, in the sluice 100 shown in FIG. 1, the water level of a channel such as a river is adjusted by opening and closing (raising and lowering) the gate 5 by the pulling mechanism 7.

  As shown in FIG. 1, the gate open / close sensor 10 includes an optical contact 1 that emits light to an optical fiber 2, a magnet 3 that generates a predetermined magnetic field, and a magnetic field applied to the optical contact 1 in an open / closed state of the gate 5. And a shielding plate 4 that shields according to the above.

  As shown in FIG. 2, the optical contact 1 includes, for example, a collimator lens 11 that converts the light Li emitted from the optical fiber 2 into parallel light, a polarizer 12 that transmits only specific linearly polarized light, and a magnetic field strength. The Faraday element 13 that rotates the plane of polarization of the light and the reflection mirror 14 that reflects the light transmitted through the Faraday element 13 are provided.

For example, the Faraday element 13 is configured to rotate the plane of polarization of light by 45 ° when the magnetic field B is applied by the magnet 3.
With this configuration, when the magnetic field B is applied to the Faraday element 13, the polarization plane of the polarized light that has passed through the polarizer 12 rotates 45 ° when passing through the Faraday element 13. Then, this transmitted light is reflected by the reflection mirror 14 and further rotated by 45 ° when passing through the Faraday element 13 again. That is, when the magnetic field B is applied to the Faraday element 13, the polarization plane of the polarized light emitted from the optical fiber 2 and transmitted through the polarizer 12 is rotated by 90 ° as a result, so that it is absorbed by the polarizer 12 in the return path, and the optical fiber 2 is not emitted.
On the other hand, if no magnetic field is applied to the Faraday element 13, the polarization plane of polarized light that has passed through the polarizer 12 does not rotate when passing through the Faraday element 13, so that it is reflected by the reflection mirror 14 and passes through the polarizer 12 as it is. The light is emitted to the optical fiber 2.

An optical contact 2 is connected to one end of the optical fiber 2, and an open / close detection device (not shown) for detecting the open / closed state of the gate 5 by receiving light (reflected light) emitted from the optical contact 1 at the other end. Is connected. That is, the open / close detection system and the gate open / close sensor 10 constitute a gate open / close monitoring system according to the present invention. The open / close detection device incorporates a light source, and light from the light source is emitted to the optical contact 1 via the optical fiber 2.
An existing optical fiber network can be used for the optical fiber 2. Therefore, if the optical fiber network is laid to the vicinity of the sluice gate, the gate opening / closing sensor 10 can be easily applied.

The optical contact 1 and the magnet 3 are installed on the support portion 6 so as to maintain a constant separation distance regardless of the open / closed state of the gate. For example, a structure such as a wall constituting the sluice body serves as the support portion 6. Since the separation distance between the optical contact 1 and the magnet 3 is always kept constant, if there is nothing that shields the magnetic field B, the magnet 3 applies a constant magnetic field B to the optical contact 1.
The shielding plate 4 is made of, for example, a magnetic material such as iron or nickel, and is disposed between the optical contact 1 and the magnet 3. That is, the shielding plate 4 can be physically and magnetically separated from each other.

FIG. 3 is an explanatory diagram showing an example of a specific mounting mode of the gate opening / closing sensor 10. In FIG. 3, the top view which looked at the sluice 100 from upper direction is shown.
As shown in FIG. 3, the optical contact 1 and the magnet 3 are fixed to the same structure (supporting part) 6 such as a wall body constituting the sluice main body. The shielding plate 4 is processed into a key shape in plan view, for example, by bending a plate-like member made of iron or nickel. The shielding plate 4 is fixed to the gate 5 on the other side so that one surface is interposed between the optical contact 1 and the magnet 3.

  Here, the shape and size of the shielding plate 4 and the mounting position are set so that at least when the gate 5 is in a closed state, the magnetic field applied to the optical contact 1 due to rattling of the gate 5 does not fluctuate. In other words, it is desirable that the magnetic field be designed to be completely shielded regardless of the backlash of the gate 5 in the closed state.

  As shown in FIG. 1 (a), when the gate 5 is in the closed state, the shielding plate 4 is interposed between the optical contact 1 and the magnet 3 arranged opposite to each other. No magnetic field is applied to 1. If no magnetic field is applied to the optical contact 1 (Faraday element 13), the light with the maximum intensity is emitted from the optical contact 1 to the optical fiber 2. Therefore, the open / close detection device detects when the light with the maximum intensity is received. It is detected as a gate closed state.

On the other hand, as shown in FIG. 1B, when the gate 5 is in a fully open state, the shielding plate 4 is positioned above and the shielding plate 4 is not interposed between the optical contact 1 and the magnet 3. Therefore, the magnetic field B is applied to the optical contact 1. Here, the completely open state is a state in which the magnetic field applied to the optical contact 1 becomes the magnetic field B, and the magnetic field applied to the optical contact 1 gradually varies as the gate 5 rises or falls. It is distinguished from.
When a magnetic field B is applied to the optical contact 1 (Faraday element 13), no light is emitted from the optical contact 1 to the optical fiber. Therefore, in the open / close detection device, when no light is received, the gate is open (completely open). ) To detect.

As described above, the gate opening / closing sensor 10 according to this embodiment includes the optical contact 1 that controls the light emitted to the optical fiber 2 according to the strength of the magnetic field, and the magnet that applies a constant magnetic field B to the optical contact 1. (Magnetic field generating part) 3 and a shielding plate (magnetic field shielding part) 4 that shields the magnetic field B applied to the optical contact 1 by the magnet 3 according to the open / closed state of the gate 5.
The optical contact 1 and the magnet 3 are installed so as to maintain a constant separation distance regardless of the open / closed state of the gate 5.

As described above, in the gate opening / closing sensor 10, the optical contact 1 and the magnet 3 are installed so as to maintain a constant separation distance regardless of the open / closed state of the gate 5, and the magnetic field B applied to the optical contact 1 is blocked by the shielding plate 4. Therefore, the open / close state of the gate 5 can be accurately monitored, and the reliability can be improved regardless of the operation time.
Specifically, by appropriately designing the size, shape, etc. of the shielding plate 4, it is possible to easily completely block the magnetic field applied to the optical contact 1 in the gate closed state. If a state in which no magnetic field is applied to the optical contact 1, that is, a state in which light having the maximum intensity is emitted from the optical contact 1, corresponds to the gate closed state, the gate open state ( Therefore, it is possible to reliably monitor the opening and closing of the gate.
Further, since the gate opening / closing sensor 10 is realized by a simple structure, it can be easily manufactured and the mounting work on the sluice gate is also facilitated.

As mentioned above, although the invention made by this inventor was concretely demonstrated based on embodiment, this invention is not limited to the said embodiment, It can change in the range which does not deviate from the summary.
In the above embodiment, the light source incorporated in the open / close detection device is used to monitor the open / close state of the gate 5 by comparing incident light and reflected light by the open / close detection device, but the optical contact 1 incorporates the light source. It is also possible to monitor the open / closed state of the gate 5 by detecting the emitted light emitted from the light source with an open / close detection device.
The internal configuration of the optical contact 1 is not particularly limited as long as the light emission state from the optical contact 1 to the optical fiber 2 can be associated with the open / close state of the gate 5.

Further, when the gate 5 shifts from the closed state to the completely open state, or vice versa, a magnetic field weaker than the magnetic field B is applied to the optical contact 1 (Faraday element 13). At this time, since the polarization plane of the polarized light transmitted through the polarizer 12 rotates in the range of 0 to 45 °, the intensity of the light emitted from the optical contact 1 is smaller than the maximum intensity when the gate is closed. .
Therefore, it is conceivable to detect the opening degree (how much open) of the gate 5 is based on the intensity of light emitted from the optical contact 1 to the optical fiber 2.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 Optical contact 2 Optical fiber 3 Magnet (magnetic field generator)
4 Shielding plate (magnetic shielding part)
5 Gate 6 Support 7 Gate Lifting Mechanism 10 Gate Open / Close Sensor 100 Sluice Gate

Claims (6)

An optical contact that controls the light emitted to the optical fiber according to the strength of the magnetic field;
A magnetic field generator for applying a constant magnetic field to the optical contact;
A magnetic field shielding unit that shields the magnetic field applied to the optical contact by the magnetic field generation unit according to an open / closed state of a gate such as a sluice or a lock gate,
The gate opening / closing sensor, wherein the optical contact and the magnetic field generation unit are installed so as to maintain a constant separation distance regardless of an opening / closing state of the gate. The optical contact is a Faraday element that rotates the polarization plane of the light emitted from the light source according to the strength of the magnetic field;
The gate opening / closing sensor according to claim 1, further comprising a polarizer capable of blocking light that has passed through the Faraday element.   The magnetic field shielding part is a plate-like member capable of physically and magnetically separating the optical contact and the magnetic field generation part, and is applied to the optical contact by moving in conjunction with opening and closing of the gate. The gate opening / closing sensor according to claim 1 or 2, wherein the magnetic field is shielded.   The gate opening / closing sensor according to any one of claims 1 to 3, wherein the magnetic field shielding portion is made of a magnetic material. A gate opening / closing sensor according to any one of claims 1 to 4,
An open / close monitoring system comprising: an open / close detection device that detects an open / closed state of the gate by receiving light emitted from the gate open / close sensor.   6. The gate opening / closing monitoring system according to claim 5, wherein the optical contact and the magnetic field generator are fixed to the same structure.

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