JP2008293331A - Glass breakage detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass breakage detection device for detecting the presence/absence of glass with high reliability while simplifying an installation operation. <P>SOLUTION: A closed loop-shaped shielding pattern 2 put in a disconnected state is formed in a window glass 1 when the window glass is broken. Also, a first resonance circuit part 5 and a second resonance circuit part 7 whose electromagnetic coupling is carried out in the disconnected state of the shielding pattern 2 are arranged so as to be opposed to each other in such a state that the shielding pattern 2 is interposed between them. An oscillation part is connected to a second resonance circuit part 7, and the electromagnetic coupling state of the both resonance circuit parts 5 and 7 is monitored, and a control part for detecting the presence/absence of the damage of glass is connected on the basis of the electromagnetic coupling state. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a glass breakage detecting device for detecting breakage of a window glass of a vehicle, for example.

Conventionally, various glass breakage detection devices for detecting breakage of a window glass of a vehicle have been proposed.
As this type of glass breakage detection device, for example, as shown in Patent Document 1, a device that detects the presence or absence of breakage of glass by detecting the presence or absence of disconnection of a resistor disposed on glass has been proposed.
JP 2003-141649 A

  However, in such a conventional glass breakage detection device, it is necessary to electrically connect the resistor disposed on the glass and the detection unit. Therefore, it is necessary to provide such a connection terminal on the glass and to take out a lead wire from the glass frame. Therefore, the installation work of the glass breakage detection device is complicated and the aesthetics are not preferable.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a glass breakage detection device capable of detecting the presence or absence of breakage of glass with high reliability while facilitating installation work. is there.

  In order to solve the above problem, in the invention according to claim 1, a shielding pattern made of a closed loop conductive material that is formed on the glass surface to be detected for breakage and is disconnected when the glass is broken, The first resonance circuit unit and the second resonance circuit unit that are arranged to face each other with the shielding pattern interposed therebetween and electromagnetically couple to each other in the disconnected state of the shielding pattern, and one of the resonance circuit units And a breakage detection means for monitoring the electromagnetic coupling state of both resonant circuit portions and detecting the presence or absence of breakage of the glass based on the electromagnetic coupling state.

  According to the above configuration, since the shielding pattern is made of a closed loop conductive material and is interposed between both resonant circuit portions, both resonant circuit portions are separated by the shielding pattern when the shielding pattern is not disconnected. Is in a state where electromagnetic coupling is difficult. On the other hand, if the shielding pattern is broken due to breakage of the glass, the shielding effect is reduced, so that both resonant circuit portions are easily electromagnetically coupled. Therefore, the breakage detection means can reliably detect the presence or absence of breakage of the glass based on the electromagnetic coupling state of both resonance circuit portions. Moreover, it is not necessary to form one of the two resonance circuit parts on the glass surface, and a shielding pattern for inhibiting electromagnetic coupling between the two resonance circuit parts may be formed on the glass surface. For this reason, it is not necessary to form a high-accuracy resonant circuit portion on the glass surface, and only a shielding pattern that does not require special accuracy needs to be formed on the glass surface. it can.

  According to a second aspect of the present invention, in the glass breakage detecting device according to the first aspect, the shielding pattern is constituted by a plurality of annular objects arranged concentrically.

  According to the above configuration, by using a plurality of concentric annular objects as the shielding pattern, the electromagnetic coupling between both resonant circuit portions is suitably shielded when the glass is not broken. On the other hand, when the glass is broken, these annular objects are disconnected and no closed loop is formed, so that the electromagnetic coupling between both resonant circuit portions is not easily shielded, and electromagnetic coupling is likely to occur. Therefore, since the electrical characteristics of both resonant circuit portions greatly change between the non-breakage state and the breakage state of the glass, the breakage detection means can reliably detect whether or not the glass is broken.

  According to a third aspect of the present invention, in the glass breakage detecting device according to the first or second aspect of the present invention, the frequency variable oscillation means for varying the oscillation frequency for the first resonance circuit unit or the second resonance circuit unit is provided. The breakage detecting means changes the oscillation frequency within a preset range including the resonance frequency of the second resonance circuit unit, and based on a change in electrical characteristics of the resonance circuit unit accompanying the change The gist of the invention is to monitor the electromagnetic coupling state of both resonant circuit parts and detect the presence or absence of breakage of the glass based on the electromagnetic coupling state.

  According to the above configuration, since the change tendency of the electrical characteristics at frequencies near the resonance frequency is greatly different between the state where both resonant circuit parts are electromagnetically coupled and the state where they are not electromagnetically coupled, even if there is a manufacturing error, etc. Even if the resonance frequency of each resonance circuit section is shifted by the above, the breakage detecting means can reliably detect the presence or absence of breakage of the glass based on the change tendency of the electrical characteristics.

  Invention of Claim 4 is a glass breakage detection apparatus as described in any one of Claims 1-3. WHEREIN: The said shielding pattern adheres a thermosetting conductive resin material to the said glass surface. It is made up of that.

  According to the above configuration, it is possible to easily and reliably form a shielding pattern that is surely disconnected due to glass breakage. As a result, the presence or absence of breakage of the glass can be detected with high reliability.

  The gist of the invention according to claim 5 is the glass breakage detection device according to any one of claims 1 to 4, wherein the breakage detection object is a window glass for an automobile.

  Generally, the window glass for motor vehicles is comprised so that the whole may be shattered by breakage of one place. For this reason, even if it is a case where a shielding pattern is arrange | positioned in any site | part of a window glass, a shielding pattern will be disconnected with breakage of this window glass. That is, it is not always necessary to provide a shielding pattern in the assumed portion assuming a portion where the window glass may be broken. Therefore, the freedom degree of arrangement | positioning in the window glass of a shielding pattern is raised.

  According to a sixth aspect of the present invention, in the glass breakage detecting device according to the fifth aspect, the window glass is provided so as to be capable of opening and closing with respect to an automobile door, and the shielding pattern is provided in the window glass. The gist is that it is provided in a portion that is always housed in the door regardless of the open / closed state.

  When the breakage detection target of the glass breakage detection device is a window glass for automobiles that can be opened and closed with respect to the door, the shielding pattern is related to the open / close state of the window glass as shown in the present invention. It is preferable to form it in a part that is always housed inside the door. According to this configuration, since the shielding pattern is always hidden behind the door, the appearance of the vehicle is good.

  The gist of the invention according to claim 7 is the glass breakage detection device according to any one of claims 4 to 6, wherein the thermosetting conductive resin material is a silver paste. .

  Unlike the case where the shielding pattern is a wire coil, for example, the shielding pattern constituted by the silver paste is surely disconnected as the window glass is broken. In particular, the breakage of the window glass can be reliably detected by applying the shielding pattern of the silver paste according to the present invention together with the window glass for an automobile described in claim 5 or 6.

  As described above in detail, according to the present invention, it is possible to detect the presence or absence of glass breakage with high reliability while facilitating installation work.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS.
As shown in FIGS. 1A and 1B, a shielding pattern 2 made of a conductive material is formed at a lower portion of one surface (for example, an indoor side surface) of a window glass 1 of a vehicle (automobile). . The shielding pattern 2 is fixed by applying and heating a paste-like thermosetting conductive resin (here, silver paste) on the glass surface of the window glass 1, and is disconnected when the window glass 1 is broken. It has become. The shielding pattern 2 is constituted by a plurality (five in this embodiment) of annular objects 2a formed concentrically, and when the window glass 1 is broken, all these annular objects 2a are disconnected. ing. By the way, the glass used as the window glass of the vehicle is configured so that the whole is broken in pieces when one place is broken. Be sure to disconnect.

  As shown in FIG. 2, the shielding pattern 2 is formed in a portion that is always housed in the door 6 even when the window glass 1 is fully closed. In addition, the first resonance circuit unit 5 and the second resonance circuit unit 7 are disposed to face each other with the window glass 1 interposed therebetween. These resonant circuit portions 5 and 7 are disposed in the door 6 so as to be separated from the window glass 1 at positions corresponding to the shielding pattern 2.

  The first resonance circuit unit 5 includes a first planar coil unit 3 formed on a substrate 21 made of a printed wiring board, a flexible printed circuit board, or the like, and both ends of the first planar coil unit 3 mounted on the substrate 21. It is comprised by the 1st capacitor | condenser functional part 4 to connect. The first capacitor function unit 4 includes, for example, a surface mount type chip capacitor and a connection unit that connects both ends of the chip capacitor to both ends of the first planar coil unit 3.

  On the other hand, the second resonant circuit unit 7 is formed on the printed wiring board 8 and has a second planar coil unit 9 disposed opposite to the first planar coil unit 3 of the first resonant circuit unit 5 with the shielding pattern 2 interposed therebetween. A capacitor 10 as a second capacitor function unit connected to one end of the second planar coil unit 9 is provided. As shown in FIG. 3, the oscillating unit 11 is between the end of the second planar coil unit 9 on the side opposite to the capacitor 10 and the end of the capacitor 10 on the side opposite to the second planar coil unit 9. It is connected. A detector 12 is connected between the connection point between the second planar coil unit 9 and the capacitor 10 and the end of the second planar coil unit 9 opposite to the capacitor 10. For this reason, the second resonance circuit unit 7 is a series resonance circuit. The detection unit 12 is connected to a control unit 13 as a breakage detection unit. The glass breakage detection device 14 is configured by the first resonance circuit unit 5, the second resonance circuit unit 7, the oscillation unit 11, the detection unit 12, and the control unit 13.

  The first resonance circuit unit 5 and the second resonance circuit unit 7 are set to the same resonance frequency (resonance frequency fc shown in FIG. 4), and the oscillation frequency of the oscillation unit 11 is set to the resonance frequency fc. For this reason, the second resonance circuit unit 7 and the first resonance circuit unit 5 are in an electromagnetically coupled state at the resonance frequency fc and a frequency in the vicinity thereof.

  The detection unit 12 detects a voltage change accompanying the impedance change of the second resonance circuit unit 7 and outputs the detection signal to the control unit 13. Since the second resonance circuit unit 7 is a series resonance circuit, in the non-electromagnetic coupling state with the first resonance circuit unit 5, as shown in FIGS. 4A and 4B, the second resonance circuit unit 7. The impedance Z of 7 is minimized at the resonance frequency fc, and the detection voltage V is maximized. On the other hand, since the first resonance circuit unit 5 functions as a parallel resonance circuit, when the resonance circuit units 5 and 7 are in an electromagnetically coupled state, as shown in FIG. The impedance Z becomes maximum at the resonance frequency fc, and the detection voltage V becomes minimum.

  The control unit 13 determines whether or not the window glass 1 is broken based on the detection signal from the detection unit 12. Specifically, as shown in FIGS. 4B and 4C, a preset voltage threshold Vth is recorded in the control unit 13, and the control unit 13 monitors a voltage change at the resonance frequency fc. . When the window glass 1 is not damaged, the electromagnetic coupling between the resonant circuit portions 5 and 7 is hindered by the shielding pattern 2, so that the resonant circuit portions 5 and 7 are not easily electromagnetically coupled. Therefore, the electrical characteristics of the second resonance circuit unit 7 in this case are electrical characteristics according to the non-electromagnetic coupling state. For this reason, as shown in FIG. 4B, the detection voltage V at the resonance frequency fc is higher than the voltage threshold Vth.

  On the other hand, when the window glass 1 is broken, the first resonance circuit unit 5 and the second resonance circuit unit 7 are likely to be electromagnetically coupled by the disconnection of the shielding pattern 2. Therefore, the electrical characteristics of the second resonance circuit unit 7 in this case are electrical characteristics according to the electromagnetic coupling state. For this reason, as shown in FIG.4 (c), the detection voltage V in the resonant frequency fc becomes lower than the voltage threshold value Vth.

  Then, the control unit 13 determines whether or not the window glass 1 is damaged based on whether or not the voltage value detected by the detection unit 12 is higher than the voltage threshold Vth, and determines that the window glass 1 is damaged. In this case, a control signal is output to a preset control target. Specifically, the control unit 13 outputs an operation control signal to, for example, a notification device as a control target, and when the breakage of the window glass 1 is detected, activates the notification device to notify the breakage of the window glass 1. For example.

Therefore, according to the present embodiment, the following effects can be obtained.
(1) Since the shielding pattern 2 is composed of a closed loop conductive material and is interposed between the resonance circuit portions 5 and 7, the shielding pattern 2 is not disconnected by the shielding pattern 2. Both resonant circuit portions 5 and 7 are in a state in which electromagnetic coupling is difficult. On the other hand, if the shielding pattern 2 is disconnected due to the breakage of the window glass 1, the shielding effect is reduced, and the two resonance circuit portions 5 and 7 are easily electromagnetically coupled. Therefore, the control unit 13 can reliably detect the presence or absence of breakage of the window glass 1 based on the electromagnetic coupling state of the two resonance circuit units 5 and 7. In addition, it is not necessary to form one of the two resonance circuit portions 5 and 7 on the glass surface, and if the shielding pattern 2 for inhibiting electromagnetic coupling between the resonance circuit portions 5 and 7 is formed on the glass surface. Good. For this reason, since it is not necessary to form a highly accurate resonance circuit part on a glass surface, and only the shielding pattern 2 which does not need special precision should be formed on a glass surface, the glass breakage detection apparatus 14 is comprised easily. be able to.

  (2) Since both the resonance circuit portions 5 and 7 can be formed on the substrate 21 or the printed wiring board 8, the both resonance circuit portions 5 and 7 having the resonance frequency fc with high accuracy can be created. Therefore, the manufacturing error range of the resonance frequency fc can be reduced.

  (3) Since the shielding pattern 2 is composed of a plurality of concentric annular objects 2a, the electromagnetic coupling between both resonant circuit portions is suitably shielded when the window glass 1 is not broken. On the other hand, when the window glass 1 is broken, the annular object 2a is disconnected and does not constitute a closed loop. Therefore, the electromagnetic coupling between the resonance circuit portions 5 and 7 is hardly shielded, and the electromagnetic coupling is likely to occur. Therefore, the electrical characteristics of the resonance circuit portions 5 and 7 greatly change between the non-damaged state and the broken state of the window glass 1, so that the control unit 13 can reliably detect whether or not the window glass 1 is broken.

  (4) The shielding pattern 2 was configured by fixing a thermosetting conductive resin material to the glass surface of the window glass 1. For this reason, it is possible to easily and reliably form the shielding pattern 2 that is surely disconnected due to breakage of the window glass 1. As a result, the presence or absence of breakage of the glass can be detected with high reliability.

  (5) The glass breakage detector 14 detects whether or not the window glass 1 for automobiles provided to be capable of opening and closing the door 6 is broken. Generally, the window glass 1 for automobiles, in particular, the side glass and the rear glass is configured so that the whole is broken in pieces at one place. For this reason, even if the shielding pattern 2 is disposed in any part of the window glass 1, the shielding pattern 2 is disconnected as the window glass 1 is broken. That is, it is not always necessary to provide the shielding pattern 2 at the assumed part of the assumed part where the window glass 1 may be damaged. Therefore, the freedom degree of arrangement | positioning in the window glass 1 of the shielding pattern 2 is raised.

  (6) When the breakage detection target of the glass breakage detection device 14 is the window glass 1 for an automobile that can be opened and closed with respect to the door 6, the shielding pattern 2 is related to the open / close state of the window glass 1. It is preferable to always form in the part accommodated in the inside of the door 6. In this way, since the shielding pattern 2 is always hidden behind the door 6, the appearance of the vehicle is good.

  (7) As the thermosetting conductive resin material constituting the shielding pattern 2, a silver paste having a fragility that is surely disconnected when the window glass 1 is broken was adopted. For this reason, for example, unlike the case where the shielding pattern 2 is a wire coil, the window glass 1 is surely disconnected as the window glass 1 is broken. In particular, the breakage of the window glass 1 can be reliably detected by applying the shielding pattern 2 made of silver paste together with the window glass 1 for automobiles.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. Here, points different from the first embodiment will be mainly described, and common points will be simply denoted by the same member numbers, and description thereof will be omitted.

  As shown in FIG. 5, the glass breakage detection device 14 according to the present embodiment is configured such that the oscillation unit 11 is changed to a frequency variable oscillation unit 23 as frequency variable oscillation means, and the frequency variable oscillation unit 23 is controlled by the control unit 13. This is different from the above embodiments in that the oscillation frequency is controlled.

  Specifically, the variable frequency oscillation unit 23 is configured to be able to oscillate at a plurality of types of frequencies including the resonance frequency fc of both the resonance circuit units 5 and 7, and the oscillation frequency is changed based on a control signal from the control unit 13. .

  When monitoring whether the window glass 1 is broken or not, as shown in FIG. 6, the control unit 13 starts a search end frequency set higher than the resonance frequency fc from a search start frequency fs set lower than the resonance frequency fc. In the frequency band up to the frequency fe, a control signal for changing to a plurality of frequencies including the resonance frequency fc is output to the frequency variable oscillator 23. And the control part 13 judges the presence or absence of the damage of the window glass 1 based on the change tendency of the detection voltage V in those frequencies.

  Specifically, when the window glass 1 is broken, as shown in FIG. 6, the detection voltage V decreases as the frequency approaches the resonance frequency fc, and increases as the distance increases. Therefore, the control unit 13 recognizes a voltage value that changes from “high → low → high” when the oscillation frequency is changed in order from the search start frequency fs to the search end frequency fe. For example, as shown by a one-dot chain line and a two-dot chain line in the figure, it is assumed that the resonance frequency fc is shifted to an error frequency fcα, fcβ, etc. due to an error in manufacturing the resonance circuit portions 5 and 7. Similarly, “High → Low → High”.

  On the other hand, when the window glass 1 is not damaged, as shown in FIG. 4B, the detection voltage V becomes the highest at the resonance frequency fc, and becomes lower as the distance from the resonance frequency fc increases. Therefore, the control unit 13 changes the oscillation frequency from the search start frequency fs to the search end frequency fe in order, “low → high → low”, or “high” when the search range is set narrower. Recognizes the voltage value that changes as “→ High → High”.

Therefore, the control unit 13 can reliably recognize the presence or absence of breakage of the window glass 1 without monitoring the voltage value change tendency without using the voltage threshold value Vth as a reference.
Therefore, according to this embodiment, in addition to the effects described in the above (1) to (7) in the first embodiment, the following effects can be obtained.

  (8) Since the change tendency of the electrical characteristics at a frequency near the resonance frequency fc is significantly different between the state where both the resonance circuit portions 5 and 7 are electromagnetically coupled and the state where they are not electromagnetically coupled. Even if the resonance frequency fc of each of the resonance circuit units 5 and 7 is shifted due to an error or the like, the control unit 13 can reliably detect whether or not the glass is broken based on the change tendency of the electrical characteristics. .

In addition, you may change embodiment of this invention as follows.
The shielding pattern 2 does not necessarily need to be configured by a plurality of concentric annular objects 2a, and may be configured by another shape such as a lattice, or may be singular. However, it is desirable that the shielding pattern 2 has a loop shape from the viewpoint of the shielding effect.

  -The 1st capacitor | condenser functional part 4 does not necessarily need to be comprised by the chip capacitor. For example, the first capacitor function unit 4 is made of a conductive material, electrodes are formed at both ends thereof, and electrodes are formed at both ends of the first planar coil unit 3. And it is good also as a capacitor | condenser functional part which consists of this electrode and a dielectric material by connecting both electrodes via a dielectric material between these electrodes.

The detection unit 12 and the control unit 13 are not necessarily connected to the second resonance circuit unit 7, and may be connected to the first resonance circuit unit 5.
-The 2nd resonance circuit part 7 does not necessarily need to be a series resonance circuit, and may be comprised by the parallel resonance circuit.

-The surface of the shielding pattern 2 may be subjected to a protective treatment such as covering with an insulating film.
-The shielding pattern 2 formed on the glass surface of the window glass 1 does not necessarily need to be composed of a thermosetting conductive resin material, and has a fragile conductivity that is surely disconnected when the window glass 1 is broken. What is necessary is just to be comprised with the property material.

-The coil part (the 1st plane coil part 3 and the 2nd plane coil part 9) which comprises each resonance circuit part 5 and 7 does not necessarily need to have comprised the planar shape.
The glass breakage detection device 14 is not necessarily applied as a breakage detection device for the window glass 1 of the vehicle, and may be applied as a breakage detection device for a window glass of a house, for example. The glass breakage detection device 14 is not necessarily applied as a breakage detection device for movable glass, and may be applied as a breakage detection device for fixed glass.

(A) is a perspective view which shows roughly the arrangement | positioning state of the glass breakage detection apparatus of one Embodiment of this invention, (b) is the partially expanded view of (a). Sectional drawing which shows roughly the installation state of the glass breakage detection apparatus of the embodiment. The circuit diagram which shows roughly the electrical structure of the glass breakage detection apparatus of the embodiment. (A)-(c) is a graph which shows the detection waveform characteristic of the glass breakage detection apparatus of the embodiment. The circuit diagram which shows schematically the electric constitution of the glass breakage detection apparatus of 2nd Embodiment of this invention. The graph which shows the detection waveform characteristic of the glass breakage detection apparatus of the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Window glass, 2 ... Shielding pattern, 2a ... Ring, 4 ... 1st capacitor function part, 5 ... 1st resonance circuit part, 7 ... 2nd resonance circuit part, 3, 9 ... Planar coil part, 10 ... Capacitor DESCRIPTION OF SYMBOLS 11 ... Oscillation part, 12 ... Detection part, 13 ... Control part as a breakage detection means, 14 ... Glass breakage detection apparatus, 23 ... Frequency variable oscillation part.

Claims (7)

A shielding pattern made of a closed loop conductive material that is formed on the glass surface to be broken and is broken when the glass is broken;
A first resonant circuit unit and a second resonant circuit unit that are arranged opposite to each other with the shielding pattern interposed therebetween and electromagnetically coupled to each other in the disconnected state of the shielding pattern;
Oscillating means connected to one of the resonant circuit sections;
A glass breakage detection device comprising: a breakage detection unit that monitors the electromagnetic coupling state of both resonant circuit portions and detects whether or not the glass is broken based on the electromagnetic coupling state.   The glass breakage detection device according to claim 1, wherein the shielding pattern includes a plurality of annular objects arranged concentrically. A variable frequency oscillation means for varying an oscillation frequency for the first resonance circuit unit or the second resonance circuit unit;
The breakage detection means changes the oscillation frequency within a preset range including the resonance frequency of the second resonance circuit unit, and performs both resonances based on a change in electrical characteristics of the resonance circuit unit due to the change. The glass breakage detection device according to claim 1 or 2, wherein the glass coupling state of the circuit unit is monitored and the presence or absence of breakage of the glass is detected based on the electromagnetic coupling state. In the glass breakage detection device according to any one of claims 1 to 3,
The said shielding pattern is a glass breakage detection apparatus comprised by adhering a thermosetting conductive resin material to the said glass surface. In the glass breakage detection device according to any one of claims 1 to 4,
The breakage detection target is a glass breakage detection device that is a window glass for automobiles. In the glass breakage detection device according to claim 5,
The window glass is provided so that it can be opened and closed with respect to the door of the automobile,
The said shielding pattern is a glass breakage detection apparatus provided in the site | part which will always be accommodated in the inside of a door irrespective of the opening / closing state in the said window glass. In the glass breakage detection device according to any one of claims 4 to 6,
The said thermosetting conductive resin material is a glass breakage detection apparatus which is a silver paste.

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