JP4481745B2 - Glass break detector - Google Patents

Description

  The present invention relates to a glass breakage detector for detecting breakage of a glass plate of a window or a door.

  Conventionally, a glass breakage detector for crime prevention has been provided for use in crime prevention systems for houses, which is attached to glass plates that divide indoors and outdoors, such as window glass and glass doors, to detect the destruction of glass plates by suspicious persons who are trying to enter the room. Has been. This type of glass breakage detector includes a sensor unit that detects the breakage of the glass plate, a sounding circuit for threatening in response to the detection, or a transmission unit that informs the information detected by the sensor unit, and the like. They are housed in a casing formed of synthetic resin or the like as in Patent Document 1 and Patent Document 2 below.

JP 2004-005057 A Japanese Patent Laid-Open No. 06-176275

  In many of the conventional glass break detectors, the sensor body is fixed inside the housing, and vibrations applied to the glass plate at the time of breakage are received through the bottom plate of the housing attached to the glass plate. Become. However, since the adhesion between the glass plate and the housing has been performed by adhering or applying an adhesive such as a double-sided tape or a solid adhesive to the entire surface of the bottom plate, the sensitivity of the glass breakage detector is low. However, it is greatly affected by temperature and humidity, causing problems such as generating false alarms or making detection impossible. In the case of template glass (glass having irregularities formed on the glass surface), the bonding area is limited by the irregularities, so that the sensitivity is generally lowered and the problem is more remarkable. In addition, depending on the specifications of the double-sided tape, it may not be able to withstand long-term durability such as deterioration due to sunlight and peeling off from the glass.

  The present invention has been made in view of the above circumstances, and is a glass breakage detector having a structure in which the sensitivity is not greatly affected by the type of glass, changes in temperature and humidity, or the passage of time. The purpose is to provide.

  The glass breakage detector according to the present invention, which has been made to solve the above problems, includes a housing mounted on a glass plate that partitions the interior and the exterior, a sensor for detecting breakage built in the housing, and an output of the sensor. And a sensitivity amplifying unit in which a part of the bottom plate is depressed and thinner than the other part is provided in a region of the bottom plate of the housing where the sensor is fixed. A vibration receiving portion that directly contacts the glass plate is provided on the back side of the sensitivity amplification portion.

  The electronic circuit includes an analog circuit that outputs the output of the sensor for detecting the destruction as an analog value, an amplifier circuit that amplifies and outputs, an A / D conversion circuit that outputs the digital value, and an operation that performs an operation on the digital value A circuit or a modulation circuit that performs AM modulation or FM modulation may be used as appropriate. Either a transmission form or wireless or wired connection may be selected. Further, the sensitivity amplifying unit may be provided at the center of the bottom plate of the housing, and a protrusion having a certain height may be formed as the vibration receiving unit so as to cross the sensitivity amplifying unit. In order to increase the adhesive strength to the glass plate, a configuration may be adopted in which an adhesive region opened laterally is provided at the edge of the bottom plate in the housing.

  According to the glass breakage detector according to the present invention, since the vibration is detected by directly contacting the vibration receiving part without touching the adhesive material, the sensitivity of the glass breakage detector due to the humidity or temperature of the adhesive material is not detected. Stabilization can be avoided, and it is possible to reliably detect even the destruction of template glass, which has been difficult to detect in the past. In addition, the sensitivity of the glass breakage detector can be adjusted by adjusting the shape and width of the sensitivity amplification unit and the sensitivity adjustment unit. Further, when the casing is pressed and adhered to the glass plate to be detected, the casing is directed to the glass plate by interposing between the casing and the glass plate excluding the vibration receiving portion. By sticking the glass breakage detector to the glass plate using an adhesive or the like that has a shrinking force to be fixed while being attracted (here, it has a restoring property and an elastic shrinkage property). The effect is more certain. Moreover, after sticking, long-term durability can be provided by applying a silicon-based adhesive to the adhesive region of the lower case.

Hereinafter, embodiments of a glass breakage detector according to the present invention will be described with reference to the drawings.
The example shown in FIGS. 1 and 2 is an example configured to take a form in which a radio signal is transmitted from a glass breakage detector, and is composed of an upper case 6 and a lower case 7 and is made of a synthetic resin and has a box shape. 2, a packing 8 to be loaded in the gap when assembling the upper and lower cases 6, 7, a piezoelectric sensor 3 for detecting vibration (destruction detection sensor) 3, an output determination of the piezoelectric sensor 3, and an alarm signal An electronic circuit including a processing circuit 9 for outputting, a communication circuit comprising a wireless communication circuit or a wired communication circuit for reporting the occurrence of glass breakage based on the alarm signal, and a power supply circuit (not shown) for supplying power to these circuits And a substrate (circuit board 10) on which is mounted.

  The peripheral portions of the upper and lower cases 6, 7 are provided with side walls 12, 13 that are fitted to each other over the entire circumference, and the packing 8 is elastically formed in a gap formed when the fitting is performed. Thus, watertightness inside and outside the housing 2 is ensured (see FIGS. 1A, 1B, 1D, and 2F). At the four corners of the side wall 12 of the upper case 6, holes (not shown) for passing the screws 11 are provided, respectively, and at the four corners of the side wall 13 of the lower case 7, screw holes (not shown) for screwing the screws of the screws 11 are shown. The upper and lower cases 6 and 7 are held in the shape of the casing 2 by the screws 11 (see FIGS. 1E and 2C).

  That is, the upper case 6 is provided with decorative ribs 15 and the like and is positioned like an upper cover of the housing 2, but in the lower case 7, the bottom plate fixes the piezoelectric sensor 3 and the circuit board 10. The base is positioned like a diaphragm that can adjust the sensitivity of the piezoelectric sensor 3.

  The lower case 7 includes a sensitivity amplifying unit 4 in which the central portion of the outer surface of the bottom plate is recessed in a rectangular shape and is thinner than the peripheral portion, and has a certain height across the sensitivity amplifying unit 4. A protrusion is provided as the vibration receiving portion 5. In addition, an adhesive region 14 that is depressed in a square shape is formed on the outer surface of the bottom plate of the lower case 7 so as to sandwich the sensitivity amplifying unit 4 up and down, and each adhesive region 14 is coated with an adhesive as the adhesive. When selecting, the side wall of the lower case 7 is opened in a notched state for the convenience of good fixing to the glass plate 1 such as releasing excess of the applied adhesive. (See FIGS. 1C and 1E and FIG. 2B).

  The sensitivity amplifying unit 4 that has been depressed into the rectangular shape is divided into two regions, wide and narrow, with the vibration receiving unit 5 as a boundary, and the wider region is used as an adhesive region 16 where an adhesive is fixed, and the narrower region is used as a sensitivity adjustment region. 17 A fixing region 18 of the piezoelectric sensor 3 is provided on the opposite side of the region where the vibration receiving unit 5 is provided. For example, the sensitivity adjustment region 17 such as a ratio between the sensitivity adjustment region 17 and the adhesion region 16 is provided. The sensitivity of the glass breakage detector will be adjusted depending on the way of providing. In this example, the vibration receiving portion 5 that vertically cuts the lower case 7 is formed at a position about 1/8 of the lower case 7, and the sensitivity adjustment region 17 and the adhesion region are disposed on both sides of the vibration receiving portion 5. 16 and the width ratio of the two is about 1: 7 (see FIGS. 1C, 1D, and 1F). If necessary, a region near the wider vibration receiving portion 5 and not having an adhesive attached may be used as the sensitivity adjustment region 17.

  The piezoelectric sensor 3 in this example has a disk shape and is fixed to the fixing region 18 with an adhesive. The circuit board 10 has an arch-shaped notch having a rounded shape sufficiently larger than the diameter of the piezoelectric sensor 3, and is arranged so as to expose the piezoelectric sensor 3. The circuit board 10 is formed with positioning holes at its four corners for fitting with downwardly extending protrusions protruding from the four corners of the bottom plate in the lower case 7, and in addition, four side walls 13 in the lower case. Since the claw that inclines inwardly protrudes downward (not shown), the circuit board 10 pushed below the lower case 7 has a tight fit between the protrusion and the positioning hole. As a result, the edge of each claw bites into the peripheral edge of the circuit board 10 and is fixed to a predetermined position on the bottom plate.

  The glass breakage detector having such a structure is attached to the glass plate 1 to be detected by using a flexible and relatively thick double-sided tape or an adhesive such as a silicon-based adhesive. For example, when the double-sided tape 19 is used, when the casing 2 is pressed and adhered to the glass plate 1 to be detected, the glass plate 1 and the casing 2 are avoided in a manner that avoids the vibration receiving portion 5. The glass breakage detector is affixed to the glass plate 1 by using a double-faced tape 19 having a contraction force that is interposed between and retracts the casing 2 toward the glass plate 1 and is fixed.

  The thickness and properties required for the double-sided tape 19 are inconvenient if the thickness is such that the attachment to the glass plate 1 is hindered, such as peeling from the glass plate 1 due to the presence of the vibration receiving portion 5. For example, before being attached to the glass plate 1 in a state where one surface is attached to the adhesive region 16, it protrudes about 0.1 mm to 0.5 mm from the surface of the vibration receiving portion 5 and glass. After being attached to the plate 1, the rubber property is such that the vibration receiving portion 5 does not float from the surface of the glass plate 1 without being peeled off while being reduced in thickness as compared to before being attached to the glass plate 1. It is necessary to have. This is the same even if a silicon adhesive having a high weather resistance is applied in place of the double-sided tape 19 (which may be used in combination). Needless to say, these adhesives are required to have weather resistance since they are used in an environment exposed to sunlight, moisture, or drying.

  In the example shown in the figure, an acrylic foam is used as a base material, and a double-sided tape having a thickness of 0.4 mm in which an acrylic adhesive material is applied on both sides thereof, the depression of the back surface of the lower case 7 is 0.3 mm, The protruding height from the surface of the vibration receiving portion 5 is 0.1 mm. The double-sided tape has a tough bonding force, excellent deformation followability and vibration absorbability depending on its material and structure, and satisfies the above thickness and properties.

  In the circuit board 10, a band-pass circuit, a comparison circuit, and an arithmetic processing circuit are formed as the processing circuit 9. When an impact due to the breakage occurs on the glass plate 1, the piezoelectric sensor 3 built in the glass breakage detector attached to the glass plate 1 has an amplitude proportional to the strain of the glass plate 1 caused by the impact. An output voltage is generated (see FIG. 3).

  The output voltage is input to the band-pass circuit constituting the processing circuit 9, and the band-pass circuit detects only the natural frequency component when the glass plate breaks from the output voltage. The natural frequency component that has passed through the band-pass circuit is further input to the comparison circuit, and when the amplitude exceeds a predetermined threshold value, the natural frequency component is detected as an alarm signal. The alarm signal is A / D converted as alarm data by the arithmetic processing circuit and output as a digital signal obtained by encoding the converted alarm data. The digital signal formed by these processing circuits 9 is modulated by the communication circuit and wirelessly transmitted from the antenna.

  As described above, the alarm data is transmitted to the monitoring device such as the home controller 20 that manages the alarm data by the electronic circuit on the circuit board 10. In this example, the alarm data is further transmitted to the outside by the notification device 21. It will be reported. In the monitoring device, it is also possible to receive the alarm and sound an alarm alarm. In the notification device 21, a resident's mobile phone or security service provider is provided through a telephone line or the like. Alternatively, it may be a specification that automatically performs processing such as reporting to the police. If the threshold adjustment circuit 22 is provided in the comparison circuit, the detection sensitivity can be adjusted relatively easily according to the specification of the glass to be attached and the installation environment.

  Since it relates to a simple and effective structural change of the housing without changing the sensor main body and the electronic control method, it contributes to the low cost and high reliability of the glass breakage detector used in the security system and the like.

An example of a glass breakage detector according to the present invention, (A): (C) BB cross section, (B): (C) CC cross section, (C): bottom view, (D ): DD sectional view of (C), (E): Side view, (F): Enlarged sectional view of essential parts of (D). 1A is a plan view of FIG. 1, FIG. 1B is a cross-sectional view taken along line AA of FIG. 1A, and FIG. It is a block diagram which shows an example of the electronic circuit structure of the system using the glass breakage detector by this invention.

Explanation of symbols

1 glass plate, 2 housing, 3 sensor, 4 sensitivity amplification unit, 5 vibration receiving unit,
6 Upper case, 7 Lower case, 8 Packing, 9 Processing circuit, 10 Circuit board,
11 screws, 12 side walls (upper), 13 side walls (lower), 14 bonding areas, 15 decorative ribs,
16 Adhesion area, 17 Sensitivity adjustment area, 18 Fixing area, 19 Double-sided tape,
20 home controller, 21 reporting device, 22 threshold adjustment circuit,

Claims (3)

The housing (2) mounted on the glass plate (1) for partitioning the interior and exterior, the sensor (3) for destruction detection built in the housing (2), and the output of the sensor (3) are reflected. And an electronic circuit for sending information,
Wherein the region for fixing the sensor (3) in the bottom plate of the housing (2), the sensitivity amplification unit outer surface of the bottom plate becomes thinner than depression and other portions provided with a (4), the sensitivity amplification unit The glass breakage detector which provided the vibration receiving part (5) which contact | abuts directly on the said glass plate (1) on the outer surface of (4) .   The sensitivity amplifying part (4) is provided at the center of the bottom plate of the casing (2), and a protrusion having a certain height is formed as the vibration receiving part (5) in a form crossing the sensitivity amplifying part (4). The glass breakage detector according to claim 1.   The glass breakage detector according to claim 1 or 2, wherein an adhesive region (14) opened laterally is provided at an edge of a bottom plate of the housing (2).

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