JP3240399B2 - Liquid leak detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention enables early detection of whether or not a leak has occurred in a leak detection target area, thereby preventing a disaster due to the leak or avoiding damage to facilities. The present invention relates to an improvement of a liquid leakage detection device.

[0002]

[Prior art] In factory facilities and other facilities,
Leakage can cause disaster or damage the facility itself, so it is necessary to know early on the occurrence of leakage. For this reason, various proposals have been made in addition to monitoring by personnel in the past, but optical confirmation means has been proposed as a simple and reliable means. For example, when light is irradiated to a filter made of thin paper or the like and liquid leaks into the thin paper, a change in the amount of transmitted light or reflected light related to the filter can be detected to determine whether there is liquid leakage. Such an apparatus has been proposed (Japanese Patent Application No. 35353 in 1987).
issue). However, as apparent from the description of the specification, the invention is directed to water, an acidic solution, an alkaline solution, an alcohol, a thinner, benzene, and the like, and a liquid having a high viscosity hardly penetrates thin paper and is not useful. However, when resetting, it requires replacement of thin paper, which is troublesome and expensive, and it is not suitable for a so-called clean room that dislikes fibrous dust because it operates thin paper, and above all, liquid with high risk has penetrated Occasionally, when handling thin paper, an unexpected disaster may occur if the handler does not pay much attention.
Further, conventionally proposed devices are characterized by breakage of the device itself due to leakage of liquid into the casing of the liquid leakage detection device, occurrence of a leakage accident based on the device, and furthermore, generation of heat or ignition due to incorrect wiring. Insufficient countermeasures were taken against the disaster, and the installation of the leak detection device could have led to a disaster. Therefore, a means has been proposed in which the filter is used also as a casing member of the liquid leakage detection device to avoid these drawbacks.
No. 01153) There is a disadvantage that the degree of change in the amount of transmitted light and reflected light of the filter is not always sufficient.

[0003]

Therefore, in order to solve the above-mentioned problems, the present invention can use a liquid leak detecting device regardless of the property of a liquid to be detected, and without using a consumable member. It is a liquid leakage detection device that can be reused any number of times, can be used safely regardless of the place of use, without causing a disaster, and accurately detects changes in the light passing and reflected by the filter. It is an object of the present invention to propose a device that can detect the presence or absence of liquid leakage accurately and quickly.

[0004]

Technical Solution In order to solve the above-mentioned problems, the present invention is arranged with respect to a liquid leakage detection target area, and has an isosceles triangle having a cross-sectional shape having an apex angle of 90 ° on an outer surface. A light-transmitting plate having a plurality of saw-toothed irregularities formed thereon to form irregularities, a light source circuit for irradiating the irregularities, and a light-receiving circuit for receiving light reflected from the transparent plate A detection signal generation circuit for detecting a change in the amount of light received by the light receiving circuit and outputting a detection result as a signal; a display circuit for displaying the change in the amount of light received by the light receiving circuit; , A current limiting circuit for coping with ignition, and the light-transmitting plate constitutes a casing member for accommodating each of the circuits described above.

[0005]

According to the present invention, as described in detail below, a transparent material or a translucent material is used to form a light-transmitting plate, and on the outer surface thereof,
Since a plurality of sawtooth-shaped irregularities having a cross-sectional shape of an isosceles triangle having an apex angle of 90 ° are engraved horizontally and in parallel, a plurality of irregularities are provided to irradiate light to the irregularities. When the light transmitting plate is placed in the liquid leakage detection target area in a state without liquid, the light can obtain desired reflected light by the concave and convex portions without being substantially affected by the brightness, color, etc. of the liquid leakage detection target area. it can. That is, when the light source circuit and the light receiving circuit are simply arranged on the same plane, for example, as shown in FIG. 3 or FIG. 4, the incident light L and the reflected light L * run in parallel and are arranged on the same plane as the light source circuit. Although the reflected light L * does not reach the light receiving circuit, in the present invention, the light receiving circuit is arranged not only on the same plane as the light source circuit but also in parallel with the horizontal direction of the unevenness, as shown in FIG. When the liquid converges and a certain amount of light is emitted, if a liquid leaks and the liquid adheres to the surface of the uneven portion, the ratio of the light from the light source to the reflected light decreases, and more light passes through the uneven portion. Therefore, since a change occurs in which the amount of light reaching the light receiving circuit decreases, the occurrence of liquid leakage can be confirmed by detecting this change. In this case, as described above,
As shown in FIG. 2, since the light from the light source is converged,
Even when the liquid only adheres to some surfaces of the projection,
Since the amount of light reaching the light receiving circuit decreases and changes,
In other words, it is possible to detect liquid leaks quickly on the entire transparent plate.
You. Not only that, as will be described later,
The convex is also on the outer surface of the casing component
According to this embodiment, the liquid to be detected can be detected without being affected by the level of the viscosity, and since it does not use consumable parts such as thin paper unlike conventional products, it can be reused many times. It is possible and does not generate dust due to conversion of consumable parts, so there is no obstacle to use in clean rooms etc. Even if the target liquid is in contact with the human body and is dangerous, there is no work to convert consumable parts, so handling is easy. is there. In the present invention, the casing further includes a light-transmitting plate as a constituent member in some embodiments , and is configured to be hermetically sealable. Thus, a disaster can be prevented, and the liquid leakage detection device can be used safely.

[0006]

The present invention will be described with reference to the drawings. FIG. 1 is an explanatory view showing an outline of an embodiment of the present invention, and the present invention is not limited to this. For the detection of liquid leakage, a casing for protecting the liquid from entering the apparatus is required. In the present invention, the entire light transmitting plate (11A) is not formed into a flat plate, but a cylinder or an upper opening. The casing (11) was formed in a box shape so that each of the circuits could be accommodated, and a lid (11B) was fitted to the circuit. Therefore, in the present invention, the light-transmitting plate (11A) is, as described above, an object to be irradiated from the light source circuit, and has a role as a constituent member of the casing (11) for accommodating each circuit.

Therefore, in order to assume the role of the former, in the center of the outer surface of the bottom of the light-transmitting plate (11A), a sawtooth-shaped unevenness having a cross-sectional shape of an isosceles triangle having a vertex angle of 90 ° is oblong and oblong. Plural pieces are cut in parallel to form a concavo-convex portion (12) so that light can be emitted from the nearest light source.

Next, in order to take the role of the latter, the locking projection (11A) is formed on the inner periphery of the opening of the light transmitting plate (11A).
1), a locking fitting (11B1) is formed at the base of the lid (11B), and the locking projection (11A1) and the locking fitting (11B1) are fitted together to form the casing (11B). ). In addition, in order to secure a seal, the lid (11
An installation groove (11B2) is formed in the outer periphery of the lower part of the base of B),
It is desirable to fit an O-ring (11C).

Therefore, the transparent plate (11A) and the lid (11)
B) and the material of the connection wire sheath may be a resin which is not damaged by liquid leakage, for example, a tetrafluoroethylene polymer, etc., in order to protect the contents, but is of course not limited to this.

The cover (11B) may be provided with a connection line lead portion (11B3) as shown in FIG. 1, for example, to protect the connection line from liquid leakage. It is preferable to screw the attachment member (11D). That is, the screw portion (11D1) formed on the inner peripheral surface of the fastening member (11D) is screwed to the screw portion (11B4) formed on the outer peripheral surface of the connection wire lead-out portion (11B3) and tightened. The tapered portion (11D2) formed on the upper inner peripheral surface of the member (11D) presses the outer periphery of the distal end of the connection line lead-out portion (11B3) inward to eliminate a gap formed between the member and the connection line Ln.

FIG. 5 is a block circuit diagram for explaining an embodiment of each of the circuits, but the configuration of each of the circuits is not limited to this.

FIG. 6 is a circuit diagram of the liquid leakage detecting circuit (2) shown in FIG.
FIG. 2 is an electric circuit diagram for explaining an example of a circuit configuration of 0) in detail.

To explain the problem with reference to FIG. 5 and FIG. 6, the liquid leakage detecting device (10) according to the present invention has a power input terminal connected to a suitable constant-voltage power line (power line) L01, L02. (Not shown) and a liquid leakage detection circuit (2
Connection lines (power lines) L11, L12 to the power input end
The power output terminal is connected via the
0) is connected to the signal input terminal via connection lines (signal lines) L12 and L13, and the liquid leakage detection circuit (2)
0) supplies necessary power from the power output to the power input terminal via connection lines (power lines) L11 and L12, and connects a signal line from the signal output terminal of the liquid leakage detection circuit (20) to the signal input terminal. Lines) L12 and L13 to receive and process the leak detection signal S1, and to process the signal from the signal output end to the connection line (signal line) L
It is conceivable to provide a liquid leakage detection processing circuit (30) for giving to a subsequent alarm device (not shown) via 03 to L05 (the connection line L12 is used as a power line and a signal line as described above). The leak detection signal processing circuit (3
0) is grounded. ).

The leak detection circuit (20) has one end connected to the leak detection signal processing circuit (30) and one end connected to the other end of a connection line (power line) L11 for supplying appropriate power. D21, the other end of which is connected to the liquid leakage detection signal processing circuit (30) at one end, and the other end of a connection line (ground line) L12 for supplying appropriate power. It is directly connected, generates light L, and transmits light to the light transmitting plate (11
A connection line (power line) that is connected at one end to a light source circuit (21) for irradiating the uneven portion (12) of A) and a liquid leakage detection signal processing circuit (30) and supplies appropriate power.
One end is connected to the other end of L11 via the diode D21, and the other end is directly connected to the other end of the connection line (ground line) L12, and is irradiated by the light source circuit (21). A light receiving circuit (22) for receiving the reflected light L * obtained by reflecting the reflected light L on the concave / convex portion (12).

The light source circuit (21) has an input terminal connected to the cathode of the diode D21, a constant current generating circuit CR for generating and outputting a constant current power, and an output terminal of the constant current generating circuit CR. , One end is connected via a protection resistor R201, and the other end is connected to the slider and the control end of the constant current generating circuit CR. A variable resistor R202 for adjusting the current amount of the constant current power output from the controller and feeding back a control signal to the constant current generating circuit CR;
An anode is connected to the other end of the transistor 202, and a cathode is directly connected to a connection line (ground line) L12, which is provided through a constant current generating circuit CR, a protection resistor R201, and a variable resistor R202. And a photodiode PD21 for generating light L in accordance with the constant current power and irradiating the light L toward the uneven portion (12).

The light receiving circuit (22) has a collector connected to a resistor R20.
3, an emitter is connected to the cathode of the diode D21, the emitter is connected to the other end of the connection line (ground line) L12, and the light transistor for receiving the reflected light L * by the uneven portion (12). PTR21 is included. Therefore, the optical transistor PTR21 is in a conductive state when the liquid leak does not adhere to the uneven portion (12) because the reflectance at the uneven portion (12) is high and the amount of the reflected light L * is large. On the other hand, when the liquid leaks to the concave and convex portions (12), most of the irradiated light L becomes transmitted light, and the reflectance in the concave and convex portions (12) becomes low.

The leak detection circuit (20) has one end connected to the leak detection signal processing circuit (30) and the other end of a connection line (signal line) L13 for supplying the leak detection signal S1. One of the signal output terminals (power input terminals) is a diode D22
The other end of the signal output terminal (power input terminal) is connected to the liquid leakage detection signal processing circuit (30) at one end to supply a liquid leakage detection signal S1 (signal line).
L12 is directly connected to the other end, and the signal input end is directly connected to the signal output end of the light receiving circuit (22). When the amount of light received by the circuit (22) changes, it is detected and a leak detection signal S1 is generated to generate a leak detection signal processing circuit (30).
Signal generation circuit / current limiting circuit (23) for outputting to the other end, and the other end of the connection line (power line) L11 having one end connected to the liquid leakage detection signal processing circuit (30). A connection line (power line) L having one of the power input terminals connected via a diode D21 and the other of the power input terminals having one end connected to the liquid leakage detection signal processing circuit (30).
12 is directly connected to the other end, and the signal input terminal is directly connected to the signal output terminal of the light receiving circuit (22). Light receiving circuit (2
A display circuit (2) for detecting when the amount of received light changes in (2) and visually indicating that a liquid leak has occurred.
4).

A detection signal generating circuit / current limiting circuit (23)
Has a collector connected to the cathode of the diode D22,
The base is connected to the signal output terminal of the light receiving circuit (22) via the resistor R204, that is, the collector of the phototransistor PTR21, and the emitter is connected to the resistor R205 and the resistor R20.
6 is connected to the other end of the connection line (ground line) L12 through the series circuit of FIG.
Is in a non-conducting state when it is in a conducting state, and the phototransistor PTR21 has a reflected light L *
When the transistor TR21 is in a non-conducting state because it cannot receive light sufficiently, the transistor TR21 is in a conducting state and outputs its operation state as a liquid leakage detection signal S1 to a liquid leakage detection signal processing circuit (30); Is connected to the base of the transistor TR21, and the base is connected to the resistor R205 and the resistor R20.
6, the emitter is connected to the other end of the connection line L12, and when the amount of current passing through the transistor TR21 is less than a predetermined value, the transistor TR21 is turned off. A transistor TR22 for preventing the amount of current passing through the transistor TR21 from becoming excessive when the amount of current passing therethrough reaches a predetermined value, thereby preventing the occurrence of the disaster. Has been taken. The detection signal generation circuit / current limiting circuit (23) receives the current from the liquid leakage detection signal processing circuit (30) via the diode D22 and the connection lines L12 and L13 when the transistor TR21 is in the conductive state, and outputs the current from the transistor TR21. Is in a non-conducting state, the diode D
Since no current is received from the liquid leakage detection signal processing circuit (30) through the connection lines L12 and L13, this current is output as the liquid leakage detection signal S1.

The display circuit (24) has an input terminal connected to the cathode of the diode D21 and an output terminal connected to the resistor R207.
And a connection line (ground line) via a series circuit of
L12 is connected to the other end, and the control end is connected to the connection point of the resistor R207 and the resistor R208.
A constant voltage generating circuit VR for generating a constant voltage power (for example, 5 V) from the constant voltage power (for example, a constant voltage of 5 to 24 V) supplied from the liquid leakage detection signal processing circuit (30) via L12. And a collector connected to the output terminal of the constant voltage generating circuit VR via a resistor R209, and a base connected via a resistor R210 to a signal output terminal of the light receiving circuit (22).
Connected to the collector of the optical transistor PTR21, and
The emitter is connected to the other end of the connection line (ground line) L12 via the photodiode PD22,
When the transistor TR21 is in the conductive state, it is in the non-conductive state, the photodiode PD22 is turned off, and the optical transistor P22 is turned off.
When the transistor TR21 is in a conductive state when it is in a non-conductive state, the transistor TR for causing the photodiode PD22 to emit light
23, and the collector is connected to a constant voltage generating circuit V via a resistor R211.
R, and the base is connected to the collector of the transistor TR23 via the resistor R212, and
The emitter is connected to the other end of the connection line (ground line) L12 via the photodiode PD23, and the transistor TR
When the transistor TR23 is in a non-conductive state, the photodiode PD23 is turned off, and when the transistor TR23 is in a non-conductive state, the photodiode PD23 is in a non-conductive state.
And a transistor TR24 for causing 23 to emit light. By the way, the photodiode PD22 visually indicates that no liquid leak has adhered to the concave and convex portions (12) when the light is in a darkened state, and has a liquid leakage adhered to the concave and convex portions when it is in a light emitting state. It is displayed visually. When the photodiode PD23 is in the light emitting state, the liquid leaks from the uneven portion (1).
In 2), it is visually displayed that no liquid is attached, and when it is in the light-off state, it is displayed that liquid leak is attached to the uneven portion (12). The photodiodes PD22 and PD23
When both are in the light-off state, it can be understood that this indicates that the power supply from the liquid leakage detection signal processing circuit (30) is stopped.

The outline of the structure of the liquid leakage detection signal processing circuit (30) is as shown in FIG. 5, but is not limited to this. Briefly, the detection signal receiving circuit (3)
1), detection circuit type compatible circuit (32), display circuit (3
5), relay device driving circuit (33), relay device (3)
4) The present invention can be utilized by providing connection lines L03, L04, L05, etc. to an alarm device or the like. In the drawing, S2 denotes a liquid leakage detection signal reception signal, S3 denotes a liquid leakage detection standardized signal, and S4 denotes a relay device drive signal.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an outline of an embodiment.

FIG. 2 is an explanatory diagram of an arrangement of a light receiving circuit and reflected light.

FIG. 3 is an explanatory diagram showing a relationship between incident light and reflected light.

FIG. 4 is an explanatory diagram showing a relationship between incident light and reflected light.

FIG. 5 is a block circuit diagram showing an outline of an embodiment.

FIG. 6 is an electric circuit diagram showing an embodiment of a liquid leakage detection circuit.

[Explanation of symbols]

Reference numeral 10: Liquid leakage detection device 11: Casing 11A: Translucent plate 11A1: Locking projection 11B ······ Lid 11B1 ····· Locking fitting part 11B2 ································································ · Screw part 11C ······ O-ring 11D ······ Tightening member 11D1 ······ Screw part 11D2 ························· ····· Uneven portion 20 ······ Leakage detection circuit D21, D22 ···· Diode L · ····· Light L * ···· ... Reflected light L11, L13. ..Resistance PD21 ... Photodiode 22... Light receiving circuit PTR21... Phototransistor R203. ··· Detection signal generation circuit · Current limiting circuit R204 to R206 ··· Resistors TR21 and TR22 ··· Transistor 24 ······· Display circuit R207 to R212 ··· Resistors TR23 and TR24 ······ Transistor PD22, PD23 ··· Photodiode VR ························································・ ・ ・ ・ ・ ・ Detection signal receiving circuit 32 ・ ・ ・ ・ ・ ・ ・ ・ ・ Detection circuit type corresponding circuit 33 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Relay device drive circuit 34 ・ ・ ・ ・ ・ ・ ・ ・ ・..Relay device 35... Display circuit

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01M 3/38 G01M 3/02

Claims (5)

(57) [Claims] 1. A liquid leakage detection area, wherein:
A transparent material or a translucent material in which a plurality of saw-toothed irregularities having an isosceles triangle having a vertical angle of 90 ° on the outer surface are engraved horizontally and in parallel to form a plurality of irregularities (12). A light-transmitting plate (11A) and a parallel arrangement with the horizontal direction of the unevenness of the unevenness (12) for irradiating the unevenness (12) from the nearest.
A light source circuit (21) which is in the same plane as the light source circuit (21), and the concavo-convex portion (12) arranged parallel to the horizontal direction of the unevenness of the reflected light from said light transmitting plate (11A) leak detection device characterized by Ru and a light receiving circuit for receiving (22) a 2. The light source circuit according to claim 1 , wherein the light transmitting plate (11A) is provided with the light source circuit.
(21) Light receiving circuit (22) and light receiving circuit (22)
To detect a change in the amount of light and output the detection result as a signal.
Signal generation circuit and current limiting circuit (23)
The casing component member which performs
1. Liquid leakage detection device 3. The light source circuit according to claim 2 , wherein the light transmitting plate (11A) is provided with the light source circuit.
(21) Light receiving circuit (22) and light receiving circuit (22)
To detect a change in the amount of light and output the detection result as a signal.
Signal generation circuit / current limiting circuit (23) and light receiving circuit
A display cycle for displaying a change in the amount of light received by the road (22)
A casing component for accommodating the road (24)
The liquid leakage detecting device according to claim 1, wherein 4. The light transmitting plate (11A) is connected to the concave and convex portions (1).
2) is formed in a cylindrical body arranged at the center of the bottom outer surface.
A locking projection (11A1) is provided on the inner periphery of the opening of the cylindrical body.
And a member protruding from the base of the lid (11B) formed separately.
The stop fitting portion (11B1) and the locking protrusion (11A1)
The light source circuit (21) and the light receiving circuit (22) are fitted together and detected.
A housing for accommodating the informing signal generation circuit / current limiting circuit (23)
3. The method as claimed in claim 2, wherein said step (c) comprises:
Liquid leak detection device 5. The light transmitting plate (11A) is provided with the concave and convex portions (1).
2) is formed in a cylindrical body arranged at the center of the bottom outer surface.
A locking projection (11A1) is provided on the inner periphery of the opening of the cylindrical body.
And a member protruding from the base of the lid (11B) formed separately.
The stop fitting portion (11B1) and the locking protrusion (11A1)
The light source circuit (21) and the light receiving circuit (22) are fitted together and detected.
An informing signal generating circuit / current limiting circuit (23) and a display circuit (2
4 ) that the casing (11) accommodating the
4. A liquid leakage detection device according to claim 3, wherein: