JP4374173B2 - Leak sensor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid leakage sensor that detects liquid leakage.
[0002]
[Prior art]
Conventionally, there is a liquid leakage sensor shown in FIG. This has a pair of detection surfaces 71, 72 that are symmetrically inclined with respect to the outer surface of the translucent member 7 that is disposed opposite to the surface to be submerged F such as the floor surface under the pipe, and from the light projecting unit 81. The detection surface 71 is irradiated with light, and the light reflected by the detection surfaces 71 and 72 is received by the light receiving unit 82. In addition, a bottom surface 73 is provided between the detection surfaces 71 and 72 so as to be in close contact with the surface to be submerged F.
[0003]
When there is no liquid leakage, most of the light emitted from the light projecting unit 81 via the detection surfaces 71 and 72 is received by the light receiving unit 82. On the other hand, when leakage occurs and, for example, the leakage comes into contact with the detection surface 71, the light emitted from the light projecting unit 81 passes through the detection surface 71, thereby exiting the light projecting unit 81 reaching the light receiving unit 82. The light is reduced. Therefore, the amount of light received by the light receiving unit 82 differs between the leaked state and the non-leakage state, and it is determined from this difference whether the liquid leaks.
[0004]
[Problems to be solved by the invention]
By the way, the light from the light projecting unit 81 is diffused so that it also irradiates the bottom surface F, passes through it, is reflected by the surface to be immersed F, and may be received by the light receiving unit 82. The surface to be submerged F is different in color, material, etc. depending on its location, and has a different light reflectance. Therefore, the amount of light from the light projecting unit 81 received by the light receiving unit 82 through the bottom surface 73 is as follows. Depending on the location of the leak sensor, it varies. Therefore, in order to maintain the detection accuracy of leak detection, the sensitivity of the leak sensor must be adjusted according to the installation location. Normally, a leak sensor is installed in a place where an operator cannot easily step in, for example, a gap between apparatuses, or a place where there is a risk that harmful liquid leaks. When the sensitivity adjustment must be performed on the side, there is a concern that the work burden on the worker will increase drastically.
[0005]
The present invention has been completed based on the above circumstances, and an object thereof is to provide a liquid leakage sensor that can avoid the influence of reflected light from the surface to be submerged.
[0006]
[Means for Solving the Problems]
As means for achieving the above object, a first aspect of the invention, a translucent member which have a recess leakage contact surface which contacts the liquid leakage occurred on the flooded surface is formed, and projected A light projecting portion arranged to transmit light obliquely at an incident angle smaller than a critical angle with respect to the liquid leakage contact surface from the inside to the outside of the light transmitting member, and the liquid leakage contact surface Based on the light receiving part arranged so that the light transmitted through the liquid leakage contact surface can be received without passing through the water immersion surface through the recess when the liquid leakage is not in contact, and the amount of light received by the light receiving part And a detecting means for detecting leakage.
[0007]
A second aspect of the present invention, a translucent member which have a recess leakage contact surface which contacts the liquid leakage occurred on the flooded surface is formed, the light projected, the inside from the outside of the translucent member A light projecting portion arranged so as to be transmitted obliquely with respect to the liquid leakage contact surface, and light transmitted through the liquid leakage contact surface when the liquid leakage contact surface is not in contact with liquid leakage The light receiving unit is arranged so as to be able to receive light without passing through the submerged surface while passing through the concave portion, and detection means for detecting leakage based on the amount of light received by the light receiving unit.
[0008]
According to a third aspect of the present invention, in the liquid crystal display device according to the first or second aspect, the light transmitting member is provided with a concave portion for detecting a leak that is opened so as to expand outward. Of these, the liquid leakage contact surface is formed by one end surface.
[0009]
The invention according to claim 4 is arranged with a first leak contact surface in contact with the leak generated on the surface to be submerged, and a space in which the first leak contact surface and the leak can be immersed, and a translucent member that have a second leakage contact surface leakage contacts and are formed recesses, the light projected, the leakage from the inside of the translucent member to the outside can be flooded The first liquid leakage contact surface is obliquely transmitted through the first liquid leakage contact surface at an incident angle smaller than a critical angle toward the space, and is oblique with respect to the second liquid leakage contact surface. through a light projecting unit arranged a to transmit, when said first and second leak to leak contact surface is not in contact, the recess passes through the first leakage contact surface And a light receiving portion arranged so as to be able to receive light that has passed through the second liquid leakage contact surface without passing through the surface to be submerged, and a light receiving amount in the light receiving portion. Characterized in place comprising a detecting means for detecting liquid leakage Te.
[0010]
According to a fifth aspect of the present invention, in the invention according to the fourth aspect, the translucent member is provided with a concave portion for detecting a leak that is opened so as to expand outward, and an end surface constituting the concave portion. Is characterized in that the first and second liquid leakage contact surfaces are formed.
[0011]
According to a sixth aspect of the present invention, in the first to third aspects of the present invention, the light projecting portion is composed of the other end portion of an optical fiber having one end opposed to the light projecting device, and the light receiving portion serves as the light receiving device. It is characterized in that it is composed of the other end of the optical fiber with one end opposed.
[0012]
[Action and effect of the invention]
<Invention of Claim 1>
When no liquid leakage occurs, the light emitted from the light projecting unit is refracted at a predetermined refraction angle when passing through the liquid leakage contact surface, and the light transmitted from the liquid leakage contact surface is received by the light receiving unit. Is done. On the other hand, when a leak occurs and the leak comes into contact with the leak contact surface, the refraction angle at the leak contact surface changes, and the optical path of the emitted light from the light projecting unit changes to reach the light receiving unit. As the amount of light decreases, the amount of received light decreases, and the detection means determines that the liquid is leaking based on the amount of received light. Therefore, when no liquid leakage occurs, the light emitted from the light projecting unit reaches the light receiving unit without being reflected by the submerged surface where the liquid can be submerged. Therefore, the light is stable regardless of the reflectivity of the submerged surface. The received light amount can be obtained.
[0013]
<Invention of Claim 2>
When no liquid leakage occurs, the light emitted from the light projecting unit is refracted at a predetermined refraction angle when passing through the liquid leakage contact surface, and the light transmitted from the liquid leakage contact surface is received by the light receiving unit. Is done. On the other hand, when a leak occurs and the leak comes into contact with the leak contact surface, the refraction angle at the leak contact surface changes, and the optical path of the emitted light from the light projecting unit changes to reach the light receiving unit. As the amount of light decreases, the amount of light received decreases, and the detection means determines that the liquid is leaking based on the amount of light received. Therefore, when there is no leakage, the light emitted from the light projecting unit reaches the light receiving unit without irradiating the surface to be submerged where the leakage can be submerged, so that it is stable regardless of the reflectance of the surface to be submerged. The received light amount can be obtained.
[0014]
<Invention of Claim 4>
When no liquid leakage occurs, the light emitted from the light projecting unit is refracted at a predetermined refraction angle when passing through the first liquid leakage contact surface, and passes through the space where the liquid leakage can be submerged to pass through the second leakage. Head to the liquid contact surface. And even when it passes through the second liquid leakage contact surface, it is refracted at a predetermined refraction angle and reaches the light receiving portion. On the other hand, when a leak occurs and the leak comes into contact with the first leak contact surface and the second leak contact surface, the refraction angle at these leak contact surfaces changes, and the emitted light from the light projecting unit changes. The amount of received light decreases as the light path changes and the light reaching the light receiving portion decreases, and the detection means determines that the liquid is leaking based on the amount of received light.
In this way, the optical path when the liquid leak occurs can be made much different from the optical path when the liquid leak does not occur, so that the detection accuracy of the liquid leak detection can be improved.
[0015]
<Invention of Claim 3 and Claim 5>
According to invention of Claim 3 and Claim 5, cleaning tools, such as a waste, come to reach the whole leak contact surface. According to this, for example, since it becomes easy to wipe off the liquid leakage, workability at the time of maintenance can be improved.
In the invention of claim 5, for example, if a ceiling surface is provided in the recess and the cross-sectional shape thereof is formed in a trapezoidal shape, the space of the inner part of the translucent member of both liquid leakage contact surfaces can be expanded. If it does in this way, it will become easy to put cleaning tools, such as waste cloth, in the back, and workability at the time of maintenance can be improved further.
[0016]
<Invention of Claim 6>
According to the sixth aspect of the invention, since the optical fiber having a small diameter is used for the light projecting unit and the light receiving unit, the space around the exit surface and the entrance surface can be saved.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
<First Embodiment>
A first embodiment of a liquid leakage sensor according to the present invention will be described with reference to FIGS. In FIG. 1, the direction of arrow X is the front.
The liquid leakage sensor of the present embodiment is attached to a surface to be submerged F of a liquid receiving pan (container) provided below a liquid storage tank (not shown), for example. This liquid leakage sensor is composed of a sensor body 1 and a holder 2, and the sensor body 1 is held by a holder 2 fixed to the surface to be submerged F.
[0018]
The holder 2 has a substantially L shape in which a rising wall portion 22 is vertically raised from two ring-shaped base portions 21, and the base portion 21 is fixed to the surface to be submerged F with bolts (not shown). In addition, the sensor main body 1 is fixed in contact with the side surface of the rising wall portion 22. The rising wall portion 22 is generally T-shaped when viewed from the front, and a holding piece 23 extends from the upper portion toward the front. Engaging grooves 24, 24 that engage with engaging ridges 12 (described later) of the case main body 11 </ b> A (described later) are formed on the opposing surfaces of the holding piece 23 in the vertical direction, leaving the central portion. Yes. In addition, a rectangular container-like accommodation recess 25 is formed on the rear side of the rising wall portion 22, and the permanent magnet 4 is accommodated therein.
[0019]
The sensor body 1 includes a substantially rectangular sensor substrate 5 on which the electric circuit shown in FIG. 7 is mounted, and a sensor case 11 formed of a translucent resin. A sensor substrate 5 is accommodated in a case main body 11A (corresponding to the translucent member described in the claims) of the sensor case 11 having a flat box shape, and a signal line C led out from the sensor substrate 5 is a case. The lid 11 </ b> B that closes the open upper surface of the main body 11 </ b> A is passed through and pulled out to the outside.
[0020]
Engagement ridges 12 and 12 are formed on the left and right sides of the case main body 11A so as to engage with the engagement recesses 24 of the rising wall portion 22 from the substantially center toward the vertical direction. As a result, the lower surface of the case main body 11A is held at a position (normal position) in contact with the surface to be submerged F.
[0021]
The electric circuit mounted on the sensor substrate 5 has a configuration as shown in FIG. A light projecting element 51 (corresponding to the light projecting part described in the claims) and a light receiving element 52 (corresponding to the light receiving part described in the claims) are arranged below the front surface of the sensor substrate 5, while The Hall IC 53 is mounted at a position facing the permanent magnet 4 directly in front at the normal position.
[0022]
The light projecting element 51 is driven by the light projecting circuit 54, and the light receiving signal from the light receiving element 52 is amplified by the light receiving circuit 56 while being synchronized by the synchronizing circuit 55. When the light receiving circuit 56 outputs a light receiving signal corresponding to the amount of light received by the light receiving element 52, this is provided to the liquid leakage detecting circuit 58 (corresponding to the detecting means described in the claims) via the integrating circuit 57, where The liquid leakage is detected by giving the result of comparison with the reference level to the abnormality detection circuit 60.
[0023]
The Hall IC 53 outputs a high level signal when the magnetic field received from the permanent magnet 4 reaches a predetermined magnetic field strength. In this embodiment, the sensor main body 1 is attached to the normal position. Sometimes a high level signal is output. The output of the Hall IC 53 is given to the attachment detection circuit 59 as shown in FIG. The attachment detection circuit 59 determines whether the output of the Hall IC 53 is a high level signal or a low level signal, and gives the result to the abnormality detection circuit 60, thereby detecting the attachment abnormality.
[0024]
As shown in FIG. 6, the central portion of the lower surface of the case main body 11A is provided with a recess 13 composed of a ceiling surface and two inclined surfaces inclined in a direction away from each other toward the outside from the ceiling surface. The cross-sectional shape is substantially trapezoidal. These inclined surfaces constitute an exit surface 13A (corresponding to a first liquid leak contact surface described in claim 4) and an incident surface 13B (corresponding to a second liquid leak contact surface described in claim 4). Further, in the case main body 11A on the opposite side to the concave portion 13, a convex portion 14 is formed in a position corresponding to the concave portion 13 so as to protrude in the inner direction, and the steps formed at the left and right ends of the convex portion 14 are formed. The portions 15A and 15B are provided with slits 16A and 16B.
[0025]
Next, the arrangement relationship among the light projecting element 51, the light receiving element 52, the exit surface 13A, and the entrance surface 13B will be described. First, the light projecting element 51 is obliquely incident at an incident angle smaller than the critical angle of total reflection with respect to the outgoing surface 13A (the critical angle in a state where no liquid leaks in contact with the outgoing surface 13A). Has been placed. The incident surface 13B is arranged so that the transmitted light from the exit surface 13A when the liquid leakage is not in contact is incident obliquely, and the light receiving element 52 is the incident surface when the liquid leakage element is not in contact with the liquid leakage. It arrange | positions in the position which receives the emitted light from the light projection element 51 which permeate | transmitted 13B.
[0026]
Therefore, when no liquid leak occurs, that is, when the liquid leak does not contact both the detection surfaces 13A and 13B, the light emitted from the light projecting element 51 has a predetermined refraction when passing through the light emission surface 13A. An optical path L that is refracted at a predetermined refraction angle and reaches the light receiving element 52 is also formed when the light is refracted at an angle toward the incident surface 13B and transmitted through the incident surface 13B (see FIG. 6). Further, when liquid leakage occurs, the refraction angle when passing through the exit surface or 13A and the entrance surface 13B is different, and the light emitted from the light projecting element 51 deviates from the optical path L and does not reach the light receiving element 52 (FIG. 8). reference).
The slit 16A plays a role of narrowing the light emitted from the light projecting element 51 within a predetermined range and eliminating light deviating from the optical path L. The slit 16B is a case where the transmitted light from the incident surface 13B is other than the optical path L. It plays the role of removing light incident on the main body 11A.
[0027]
Next, the operation of the liquid leakage sensor of this embodiment will be described.
First, the holder 2 is attached to the surface to be submerged F, and the engaging ridges 12 of the case main body 11A are pushed down from above so as to engage with the engaging grooves 24, and are held in the normal position. If the sensor case 11 is not held at the normal position, the signal level from the Hall IC 53 becomes a low level, and the abnormality detection circuit 60 receives this result from the attachment detection circuit 59 and outputs an abnormality detection signal. As a result, a mounting abnormality is detected.
[0028]
When no liquid leakage occurs, the light emitted from the light projecting element 51 passes through the optical path L, passes through the light exit surface 13A and the light incident surface 13B, and reaches the light receiving element 52 (see FIG. 6). Then, since most of the light emitted from the light projecting element 51 is received by the light receiving element 52, the light receiving level of the amount of received light exceeds the reference level set in the leakage detection circuit 58, and this result is detected as an abnormality. The circuit 60 determines that there is no leakage.
[0029]
Here, when a leak occurs for some reason, the leak comes into contact with the exit surface 13A and the entrance surface 13B. Then, since the light emitted from the light projecting element 51 has a refraction angle different from the refraction angle when the leaked liquid is not in contact with the light exiting surface 13A, the light transmitted through the light exiting surface 13A passes through the submerged surface F. It is reflected and travels toward the incident surface 13B or directly toward the incident surface 13B. Further, since the refraction angle is different also on the incident surface 13B, the light does not reach the light receiving element 52, and the light incident from the point deviating from the optical path L is prohibited from entering the case main body 11A by the slit 16B. Does not reach the light receiving element 52 (see FIG. 8).
As a result, the level of light received from the light receiving element 52 is much lower than that in the case where no leakage occurs, and the leakage detection circuit 58 determines that the level is below the reference level and receives this result. The abnormality detection circuit 60 detects the occurrence of leakage.
[0030]
As described above, according to the liquid leakage sensor of the present embodiment, when no liquid leakage occurs, the light emitted from the light projecting element 51 is received by the light receiving element 52 without passing through the immersion surface F. Thus, a stable amount of received light can be obtained regardless of the light reflectance of the surface F to be immersed.
Further, in a state where liquid leakage has occurred, the light emitted from the light projecting element 51 travels in a direction deviating from the optical path L toward the light receiving element 52 by both the detection surfaces 13A and 13B. The liquid leakage is detected accurately based on this. Further, since light from other than the optical path L is prevented from reaching the light receiving element 52 by the slits 16A and 16B, the detection accuracy is higher.
[0031]
Furthermore, since the recess 13 is formed so that the cross-sectional shape thereof becomes a trapezoidal shape, the cleaning tool or the like can easily reach the entire surfaces 13A and 13B when cleaning the exit surface 13A and the entrance surface 13B for maintenance or the like. There is also an advantage.
[0032]
Second Embodiment
Next, a second embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part same as 1st Embodiment, the overlapping description is abbreviate | omitted, and description of the same effect | action and effect is also abbreviate | omitted.
In the liquid leakage sensor of this embodiment, the light projecting unit and the light receiving unit are configured by the open ends 61A and 62A of the optical fibers 61 and 62, respectively. That is, the light emitted from the light projecting element 51 is emitted from the opening end 61A toward the emitting surface 13A via the optical fiber 61, and the light from the opening end 61A that has passed through the incident surface 13B is emitted from the opening end of the optical fiber 62. In this configuration, the light enters the light receiving element 52 and enters the light receiving element 52. In this way, it is possible to save the space around the exit surface 13A and the entrance surface 13B in the case body 11A, and is particularly suitable when the space around the exit surface 13A and the entrance surface 13B is limited. It is.
[0033]
<Third Embodiment>
A third embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part same as 1st Embodiment, the overlapping description is abbreviate | omitted, and description of the same effect | action and effect is also abbreviate | omitted.
In the liquid leakage sensor of the present embodiment, the light exit surface 13A (corresponding to the liquid leakage contact surface according to claim 1) is formed obliquely with respect to the surface to be submerged F so that the incident surface 13B is vertical. Forming. Specifically, the light projecting element 51 obliquely enters the emitted light with an incident angle smaller than the critical angle of total reflection with respect to the outgoing surface 13A (the critical angle in a state where no liquid leakage is in contact with the outgoing surface 13A). In addition, the transmitted light when the liquid leakage is not in contact is disposed so as to be perpendicularly incident on the incident surface 13B, and the light receiving element 52 is disposed at a position for receiving the transmitted light from the incident surface 13B. Yes. Thus, an optical path L is formed between the light projecting element 51 and the light receiving element 52 (see FIG. 10A).
[0034]
Hereinafter, the operation of the present embodiment will be described.
In a state where no liquid leakage occurs, the light emitted from the light projecting element 51 reaches the light receiving element 52 along the optical path L. On the other hand, in the state where liquid leakage has occurred, the refraction angle at the light exit surface 13A differs from that when the liquid leak is not in contact with the liquid leak coming into contact with the light exit surface 13A. Accordingly, since the light path L deviates from the light receiving element 51, the light receiving element 52 does not receive light (see FIG. 10B).
[0035]
<Fourth embodiment>
The fourth embodiment of the present invention will be described below with reference to FIG. In addition, the same code | symbol is attached | subjected to the part same as 1st Embodiment, the overlapping description is abbreviate | omitted, and description of the same effect | action and effect is also abbreviate | omitted.
In the liquid leakage sensor of the present embodiment, the exit surface 13A is formed to be perpendicular to the surface to be submerged F, and the incident surface 13B (corresponding to the liquid contact surface according to claim 2) is inclined obliquely. Forming. Specifically, the light projecting element 51 is arranged so that the emitted light is perpendicularly incident on the exit surface 13A, and the incident surface 13B has a critical angle of total reflection of the transmitted light from the exit surface 13A (leakage is caused on the entrance surface 13B). It is arranged so that it is incident obliquely at an incident angle smaller than the critical angle in a non-contact state. The light receiving element 52 is disposed at a position for receiving the transmitted light from the incident surface 13B. Thus, an optical path L is formed between the light projecting element 51 and the light receiving element 52 (see FIG. 11A).
[0036]
Hereinafter, the operation of the present embodiment will be described.
In a state where no liquid leakage occurs, the light emitted from the light projecting element 51 reaches the light receiving element 52 along the optical path L. On the other hand, in a state in which leakage has occurred, by leakage to the incident surface 13B contacts, the refraction angle of the incident surface 13B is different from when the leak is not in contact. Therefore, since the light path L deviates from the light receiving element 52 , the light receiving element 52 does not receive light (see FIG. 11B).
[0037]
<Fifth Embodiment>
Hereinafter, a fifth embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part same as 1st Embodiment, the overlapping description is abbreviate | omitted, and description of the same effect | action and effect is also abbreviate | omitted.
In the liquid leakage sensor of the present embodiment, the exit surface 13A (corresponding to the first liquid leakage contact surface described in claim 4) and the incident surface 13B (corresponding to the second liquid leakage contact surface described in claim 4). And the exit surface 13A and the entrance surface 13B are inclined so as to be separated from each other in the direction away from the surface to be submerged F. Also in this embodiment, an optical path L is formed between the light projecting element 51 and the light receiving element 52. When no liquid leakage occurs, the light from the light projecting element 51 is received by the light receiving element 52 (see FIG. 12A). When the liquid leakage occurs, the light receiving element 52 deviates from the optical path L. Light is not received (see FIG. 12B).
[0038]
<Sixth Embodiment>
The sixth embodiment of the present invention will be described below with reference to FIG. In addition, the same code | symbol is attached | subjected to the part same as 1st Embodiment, the overlapping description is abbreviate | omitted, and description of the same effect | action and effect is also abbreviate | omitted.
In the liquid leakage sensor according to the present embodiment, the emission surface 13A (corresponding to the first liquid leakage contact surface described in claim 4) is provided in parallel with the immersion surface F, and the incident surface 13B (claim 4). (Corresponding to the second liquid leakage contact surface) is provided obliquely with respect to the surface to be submerged F. Also in this embodiment, an optical path L is formed between the light projecting element 51 and the light receiving element 52. Thus, when no liquid leakage occurs, the light from the light projecting element 51 is received by the light receiving element 52 (see FIG. 13A), and when liquid leakage occurs, the light receiving element deviates from the optical path L. 52 does not receive light (see FIG. 13B).
[0039]
<Seventh embodiment>
The seventh embodiment of the present invention will be described below with reference to FIG. In addition, the same code | symbol is attached | subjected to the part same as 1st Embodiment, the overlapping description is abbreviate | omitted, and description of the same effect | action and effect is also abbreviate | omitted.
In the liquid leakage sensor according to the present embodiment, the emission surface 13A (corresponding to the first liquid leakage contact surface according to claim 4) and the incident surface 13B (second liquid leakage contact according to claim 4) face each other. (Corresponding to the surface) is provided in parallel with the surface to be submerged F, and the exit surface 13A is located farther from the surface to be submerged F than the incident surface 13B. Also in this embodiment, an optical path L is formed between the light projecting element 51 and the light receiving element 52. Thus, when no liquid leakage occurs, the light from the light projecting element 51 is received by the light receiving element 52 (see FIG. 14A), and when liquid leakage occurs, the light receiving element deviates from the optical path L. 52 does not receive light (see FIG. 14B).
[0040]
<Eighth Embodiment>
Hereinafter, an eighth embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part same as 1st Embodiment, the overlapping description is abbreviate | omitted, and description of the same effect | action and effect is also abbreviate | omitted.
In the liquid leakage sensor of the present embodiment, as shown in FIG. 14, the base portion 21 of the holder 2 is fixed by a bolt to the back side of the plate surface P projecting from a wall surface (not shown). The sensor body 1 is held with the lower surface of the case body 11A facing downward.
In this way, even if leakage occurs, the holder 2 does not come into contact with the leakage, so that it is possible to save the trouble of wiping off the leakage.
[0041]
<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) In the third to seventh embodiments, the configuration using the light projecting element 51 and the light receiving element 52 is shown. However, for example, an optical fiber may be used. It is particularly suitable when the space around the entrance / exit surface is limited as in the fifth and seventh embodiments.
[Brief description of the drawings]
FIG. 1 is a perspective view of a leak sensor according to the first embodiment. FIG. 2 is a top side view of the leak sensor. FIG. 3 is a side view of the leak sensor. ] AA side sectional view of the leak sensor [FIG. 6] BB sectional view of the leak sensor showing the optical path in a non-leakage state [FIG. 7] A diagram showing the configuration of the electric circuit of the leak sensor FIG. 8 is a cross-sectional view of the leak sensor BB showing the optical path in the leaked state. FIG. 9 is a schematic diagram of the leak sensor according to the second embodiment. FIG. 10 is a schematic diagram of a liquid leakage sensor according to the third embodiment. FIG. 11A is a light path in a non-leakage state. FIG. 10B is a light path in a liquid leakage state. Schematic diagram of sensor (A) Optical path in non-leakage state (B) Optical path in liquid leakage state [FIG. 12] Schematic diagram of liquid leakage sensor according to the fifth embodiment (A) Optical path in liquid leakage state (B) Optical path in liquid leakage state [FIG. 13] Schematic diagram of liquid leakage sensor according to the sixth embodiment (A) Optical path in non-leakage state (B) Optical path in liquid leakage state [FIG. Schematic diagram of leak sensor according to seventh embodiment (A) Optical path in non-leak state (B) Optical path in leak state [FIG. 15] Perspective view of leak sensor according to eighth embodiment [FIG. Schematic diagram of liquid leakage sensor [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Sensor main body 13A ... Outgoing surface 13B ... Incident surface 51 ... Light projecting element 52 ... Light receiving element 58 ... Liquid leak detection circuit

Claims (6)

And a translucent member to have a recess leakage contact surface leakage occurring on the flooded surfaces are in contact is formed,
A light projecting portion arranged to transmit the projected light obliquely at an incident angle smaller than a critical angle with respect to the liquid leakage contact surface from the inside to the outside of the light transmitting member;
A light receiving portion disposed so as to be able to receive the light transmitted through the liquid leakage contact surface when the liquid leakage contact surface is not in contact with the liquid immersion surface without passing through the water immersion surface while passing through the concave portion;
A liquid leakage sensor comprising: a detecting means for detecting liquid leakage based on the amount of light received by the light receiving unit. And a translucent member to have a recess leakage contact surface leakage occurring on the flooded surfaces are in contact is formed,
A light projecting unit arranged to transmit the projected light obliquely with respect to the liquid leakage contact surface from the outside to the inside of the translucent member;
A light receiving portion disposed so as to be able to receive the light transmitted through the liquid leakage contact surface when the liquid leakage contact surface is not in contact with the liquid leakage without passing through the water immersion surface through the recess;
A liquid leakage sensor comprising: a detecting means for detecting liquid leakage based on the amount of light received by the light receiving unit.   The translucent member is provided with a recess for detecting a leak that is opened so as to expand outward, and the leak contact surface is formed by one end face of the recess. The liquid leakage sensor according to claim 1 or 2. The first leak contact surface that contacts the leak generated on the surface to be submerged, and the first leak contact surface and the space where the leak can be immersed are arranged, and the leak contacts. and a translucent member Ru with a recess in which the second leak contact surface is formed,
The projected light is directed toward the space where the liquid leakage can be submerged from the inside to the outside of the translucent member, with respect to the first liquid leakage contact surface at an incident angle smaller than a critical angle. A light projecting unit arranged to transmit obliquely through the liquid contact surface and to transmit obliquely with respect to the second liquid leakage contact surface;
When no liquid leaks in contact with the first and second liquid leak contact surfaces, the second liquid leaks through the first liquid leak contact surface, passes through the recess, and does not pass through the submerged surface. A light receiving portion arranged to be able to receive light transmitted through the leakage contact surface;
A liquid leakage sensor comprising: a detecting means for detecting liquid leakage based on the amount of light received by the light receiving unit.   The translucent member is provided with a recess for detecting a leak that is opened so as to expand outward, and the first and second leak contact surfaces are formed by the end surfaces constituting the recess. The liquid leakage sensor according to claim 4, wherein: The light projecting part is composed of the other end of the optical fiber with one end facing the light projecting element,
The liquid leakage sensor according to any one of claims 1 to 5, wherein the light receiving portion is configured with an other end portion of an optical fiber having one end opposed to the light receiving element.

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