JPH0844957A - Alarm device for steal of automobile or the like - Google Patents

Abstract

PURPOSE:To provide the alarm device for the steal of the automobile, etc., which generates proper alarms corresponding to vibrations in all directions and reacts to only vibrations due to mischief, a stealing act, etc., as to an automobile alarm device which uses a piezoelectric element as a detecting means that detects vibrations of the automobile due to mischief, a stealing act, etc. CONSTITUTION:This device is provided with a vibration member 12 which is arranged in contact with the piezoelectric element 11 and a helical spring 13 which is fixed to the surface of the vibration member 12, and proper alarms can be generated by both the vibration member 12 and helical spring 13 according to the directions and frequency bands of the vibrations due to the mischief and stealing act.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alarm device for theft of a vehicle, and more particularly to the above alarm device using a piezoelectric element as a detecting means for detecting vibration of the vehicle caused by mischief or theft.

[0002]

2. Description of the Related Art By arranging the vehicle at a predetermined place in a parked car, when the car is mischievous or stolen, the owner at a distant place is notified to that effect, or There is provided an alarm device that emits a loud alarm sound.

FIG. 3 is a block circuit diagram of a conventional alarm device, and FIG. 4 is a block diagram of its detecting means. 3 and 4
The alarm device shown in (1) is disclosed in Japanese Utility Model Laid-Open No. 5-46623, and a piezoelectric element 51 is used for its detecting means 50. A weight 52 is attached to the piezoelectric element 51, and at least a part of the surface of the piezoelectric element 51 and the weight 52 is covered with a silicone rubber coating 53. The piezoelectric element 51, the weight 52, and the silicon-based rubber coating 53 are supported at a predetermined height position by a metal piece 52 erected on the substrate P.

According to the above construction, the weight 52 vibrates in response to the illegal contact with the automobile, and the weight 51 causes the piezoelectric element 5 to move.
By pressing 1 intermittently, its impedance is changed and the output of the piezoelectric element 51 is taken out as a detection signal.

Therefore, as shown in FIG. 4, and on the output side of the piezoelectric element 51, there is provided a low-pass filter 61 for outputting only a signal in the ultralow frequency range of 1 to 5 Hz accompanying the swing of the vehicle body. , And a bandpass filter 62 for outputting only a signal in a low frequency range of 30 to 50 Hz due to the vibration of the vehicle body are connected in parallel with each other, and the judging means 63, 64 corresponding to each of them.
Is output to a notification means (not shown) in the subsequent stage.

With this configuration, vibrations of relatively high frequency such as external siren sound and acoustic noise are blocked by the low pass filter 61 and the band pass filter 62,
Only the signals in the ultra-low frequency range that occur when an automobile is jacked up illegally or the low-frequency range signals that occur when a window glass is tapped are detected to prevent malfunction of the notification means in the subsequent stage. be able to.

Further, the silicone rubber coating 53
Since the piezoelectric element 51 is protected by this, the impedance change of the piezoelectric element 51 due to the instantaneous temperature change or the light amount change can be prevented, and the malfunction can be prevented.

[0008]

However, while vibrations in all directions such as up, down, left and right are applied to the mischief or theft of the automobile, the vibration direction reflected in the impedance change of the piezoelectric element 51 is the above-mentioned actual vibration. Only the component of the arrangement direction (arrow direction in FIG. 3) of the weight 52 and the piezoelectric sensor 51 in the direction. Therefore, for example, when a mischief that vibrates with a constant amplitude in the vertical direction with respect to the automobile but is hardly shaken in the direction of the arrow is applied, the weight 52 almost does not press the piezoelectric element 51. Since it does not vibrate, there is a case in which the output of the piezoelectric element 51 does not change sufficiently and an alarm is not issued even though mischief is added, which may cause malfunction.

Further, detecting means 50 (piezoelectric element 51, weight 5)
Since 2) itself is a component having a large natural frequency, it tends to have low sensitivity to the above-mentioned vibration of an ultra-low frequency of about 1 to 3 Hz, and an appropriate alarm may not be issued.

The present invention has been proposed in view of the above-mentioned conventional circumstances, and an appropriate alarm is issued in response to vibrations in all directions, and only vibrations caused by mischief or theft are reacted. The present invention aims to provide an alarm device for a stolen car or the like.

[0011]

In order to achieve the above object, the present invention provides an alarm for theft of a vehicle using a piezoelectric element as a detection means for detecting the vibration of a parked vehicle caused by mischief or theft. The following means are adopted in the device. That is, as shown in FIG. 1, the vibrating member 12 closely attached to the piezoelectric element 11 and the spiral spring 13 fixed to the surface of the vibrating member 12 are provided.

[0012]

The vibration frequency of the car caused by mischief or theft is in the ultra-low frequency range of about 1 to 4 Hz, or a number 1
As shown in FIG. 1, the low-frequency range is around 0 Hz, and the vibration direction at that time is the X-axis direction, which is the arrangement direction of the piezoelectric element 11 and the vibration member 12, the Y-axis direction, which is the vertical direction, and the horizontal direction. Z, which is the direction perpendicular to the X-axis direction.
It can be regarded as a combination of vibration components in three directions orthogonal to each other in the axial direction.

Therefore, in the above structure, the vibrating member 12 is mainly tuned to the vibration in the low frequency region of about several tens Hz, and the above X
It vibrates with an amplitude according to the axial vibration component. On the other hand, the spiral spring 13 synchronizes with the vibration of the above-mentioned ultra-low frequency such that the vibrating member 12 does not vibrate in synchronism with each other, and further, the spiral spring 13 and the vibrating member 12 are responsive to each vibration component in the Y-axis direction and the Z-axis direction. It swings about the joint. The swinging motion of the spiral spring 13 vibrates and drives the vibrating member 12 in the X-axis direction, and as a result, all of the vibration vibrates regardless of the vibration frequency or the vibration direction of the vibration that is illegally applied to the automobile. It is detected as the amplitude of the vibration component of the member 12 in the X-axis direction, and the variation in the sensitivity of the alarm device caused by the vibration frequency and the vibration direction is corrected.

The vibration member 12 and the spiral spring 1 are mainly used for high-frequency vibration caused by noise outside the vehicle.
Both 3 are less likely to vibrate, and a malfunction that issues an alarm is prevented even though there is no mischief or theft.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a side view of a detecting portion of an embodiment according to the present invention. As shown in FIG. 1, the detection means 1 of this embodiment
The piezoelectric element 11 is used for
A vibrating member 12 made of a metal plate having a predetermined weight is closely arranged on one surface side of 1. Further, a spiral spring 13 is fixed to the surface of the vibrating member 12 on the side opposite to the piezoelectric element 11 so that its axial center is perpendicular to the surface direction of the vibrating member 12.

The piezoelectric element 11, the vibrating member 12 and the spiral spring 13 are supported at a predetermined height position by a metal piece 14 standing on the substrate P. A predetermined voltage is applied to the piezoelectric element 11 by turning on the main switch Sw, and the displacement of the impedance of the piezoelectric element 11 accompanying the vibration of the vibrating member 12 will be described later. Will be reflected in the output So from the detection means 1.

FIG. 2 is a block circuit diagram of an embodiment according to the present invention. As shown in FIG. 2, the output So of the detecting means 1 is amplified by the amplifying means 2 and input to the judging means 3, The determination means 3 is adapted to generate an alarm signal Sa indicating that an alarm should be issued when a voltage displacement above a predetermined level is detected.

Incidentally, it is possible to provide the judging means 3 with a low-pass filter for removing an ultra-low frequency component of the output So of the detecting means 1 or a band-pass filter for passing only the low-frequency component. Only the vibration associated with the illegal intrusion can be selectively detected and used as the criterion.

The alarm signal Sa thus formed in the judging means 3 is input to the timer means 5 through the OR gate 31 and sets the timer means 5. When the timer means 5 is set in this way, the timer means 5 measures a predetermined time, and if the main switch Sw is not turned off within the predetermined time, the timer means 5 outputs a time-up signal, The alarm signal Sa is input to the notification means 4 via the AND gate 32, and thereby the notification means 4 is activated.

Basically, the notification means 4 operates even when the owner of the vehicle opens the door while the main switch Sw is turned on, but the timer means 5 notifies from the vibration detection. Since the grace time is set before the operation of the means 4, the notification means 4 is provided within the grace time.
Does not work.

Further, the ON signal Son of the main switch Sw is also inputted to the timer means 5 via the OR gate 31, and the main switch Sw is turned ON.
Further, the notification means 4 is not operated within a predetermined time, thereby preventing the owner from issuing an alarm between the time when the owner sets the alarm device and the time when the owner leaves the car.

When vibration caused by mischief or theft is applied to an automobile equipped with the alarm device having the above-mentioned configuration, the vibration frequency is in the ultra low frequency range of about 1 to 4 Hz, or several tens of Hz. In the front and rear low frequency regions, and the vibration direction at that time is as shown in FIG.
And the vibration member 12 are arranged in the X-axis direction, the vertical Y-axis direction, and the horizontal direction and the Z-axis direction that is a direction perpendicular to the X-axis direction. Can be regarded as the composition of.

Therefore, in the above construction, the vibrating member 12 is mainly tuned to the vibration in the low frequency range of about several tens Hz, and the above X
It vibrates with an amplitude according to the axial vibration component. On the other hand, the spiral spring 13 reacts with the vibration in the extremely low frequency range such that the vibrating member 12 does not vibrate in synchronism with each other, and further, the spiral spring 13 and the vibrating member 12 respond to the respective vibrating components in the Y-axis direction and the Z-axis direction. It swings about the joint. Such a spiral spring 13
The oscillating motion of the motor drives the vibrating member 12 in the X-axis direction. As a result, regardless of the vibration frequency or the vibration direction of the vibration that is illegally applied to the vehicle, all the vibration is generated in the X-axis of the vibrating member 12. It is detected as the amplitude of the vibration component in the direction, and the variation in the sensitivity of the alarm device caused by the vibration frequency and the vibration direction is corrected.

The vibration member 12 and the spiral spring 1 are mainly used for high-frequency vibrations caused by noise outside the vehicle.
Both 3 are less likely to vibrate, and a malfunction that issues an alarm is prevented even though there is no mischief or theft.

As an example of the above-mentioned vibration, when a vibration mainly in the vertical direction (Y-axis direction) is applied at an extremely low frequency of 1 to 3 Hz due to an illegal jack-up, the spiral spring 13 is mainly used. It oscillates greatly, so that the vibrating member 1
2 is driven so as to vibrate in the X-axis direction, and the impedance of the piezoelectric element 11 is displaced. This gives the output So with a voltage displacement sufficient for the determination means 3 to generate the alarm signal Sa.

When a vibration mainly in the lateral direction (X or Z axis direction) is applied at a frequency of several tens Hz higher than the above frequency, such as hitting a window glass, a vibration component in the X axis direction. The amplitude of the vibrating member 12 due to the swinging motion of the spiral spring 13 due to the vibration component in the Z-axis direction is added to the amplitude of the vibrating member 12 to cause a sufficient level of voltage displacement in the output of the piezoelectric element 11. An alarm signal Sa is generated in the judging means 3.

Further, when vibration in the lateral direction (X or Z-axis direction) is applied at a relatively low frequency such as shaking the vehicle laterally, the vibrating member 12 and the spiral spring 13 are both moved in the same manner as above. Since it vibrates (swings), the piezoelectric element 11
A sufficient level of voltage displacement appears.

Furthermore, it is difficult for both the vibrating member 12 and the spiral spring 13 to vibrate with respect to vibrations of high frequency such as ambient environmental noise and siren sound of an emergency car, and the output of the piezoelectric element 11 is difficult. Even if no voltage displacement appears and no mischief or theft is applied, a malfunction such as issuing an alarm is prevented.

As described above, according to the above-mentioned embodiment, the spiral spring 1 is wound around the vibrating member 12 which is closely attached to the piezoelectric element 11.
Although it has a very simple structure of fixing 3
An alarm can be issued based on the absolute amount of vibration for vibrations in all directions with respect to a parked car such as mischief or theft, and the alarm means 4 operates for vibrations that do not cause actual damage such as ambient noise. There is no malfunction that would cause it.

Further, the natural frequency of the spiral spring 13 can be arbitrarily set, and even if the piezoelectric element 11 or the vibrating member 12 is made into a minute component, the response sensitivity to the vibration of the ultra low frequency is impaired. It is possible to reduce the size of the alarm device itself.

In the above-mentioned embodiment, since no special circuit structure for improving the response sensitivity to vibrations of ultra-low frequency and low frequency is adopted, the alarm device itself can be provided at low cost.

However, the present invention is not limited to the above-mentioned embodiment, for example, the circuit constitution of the latter stage of the detecting means 1 is arbitrary, and for example, the circuit constitution as shown in FIG. 4 can be adopted. The notification means can be adopted not only in a structure in which a large volume is used for notification, but also in a structure in which a notification signal is transmitted to a receiving device brought by a holder in a remote place.

[0033]

As described above, according to the present invention, by adopting a very simple structure in which a spiral spring is fixed to a vibrating member closely arranged on a piezoelectric element, the absolute vibration of vibrations in all directions applied to an automobile can be obtained. The alarm can be issued based on the amount, and the alarm can be issued only in response to vibrations caused by mischief or theft. Therefore, according to the present invention, a malfunction that issues an alarm without actually using any special circuit configuration and does not give an alarm even if there is actual mischief or theft, but does not have any malfunction or mischief or theft. Has the effect of being eliminated.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a detection unit according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of an embodiment according to the present invention.

FIG. 3 is a configuration diagram of a detection unit of a conventional example.

FIG. 4 is a block diagram showing a circuit configuration of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Detecting means 11 Piezoelectric element 12 Vibration member 13 Spiral spring

Claims (1)

[Claims] 1. An alarm device for theft of a vehicle using a piezoelectric element as a detection means for detecting the vibration of a parked vehicle caused by mischief or theft, wherein a vibrating member closely attached to the piezoelectric element is provided. An alarm device for theft of an automobile, comprising a spiral spring fixed to the surface of the vibrating member.