JP2000304761A - Impact sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an impact sensor wherein an impact detecting part is externally fitted to a sensor main body so that it can be set at an arbitrary position away from the sensor main body while a plurality of impact detecting parts are connected to the sensor main body for acquiring a detection signal regardless of a setting position. SOLUTION: The sensor main body 10 comprises an impact detecting means, an alert means, a power source 12, and a CPU 13. The impact detecting means is externally fitted to the sensor main body 10 and the electric output from the impact detecting means is inputted in the CPU 13 through a low-noise low- damping signal line. With a plurality of impact detecting means provided, at least one of them is externally fitted to the sensor main body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an impact sensor. More specifically, the present invention relates to a shock sensor provided with alarm means for detecting a shock in an automobile or the like and issuing an alarm or the like.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram schematically showing a configuration of a conventional impact sensor. This conventional impact sensor,
Shock detection unit as shock detection means mainly composed of piezoelectric elements
The impact detection unit 70 includes a lead wire for fixing the piezoelectric element provided with the vibrating weight on a substrate and picking up an electrical output of the piezoelectric element generated by an impact such as mechanical vibration. Are connected to the electrodes of the piezoelectric element.

The shock sensor main body 60 (hereinafter referred to as "sensor main body") is constituted by the shock detector 70, a power supply 12, a CPU 13 as a central processing unit, and a speaker 14 as alarm means. I have.

Such an impact sensor is installed in, for example, an automobile, and is effective as a safety device that detects an impact due to various road surface irregularities and issues an alarm, and notifies the driver of the impact by the alarm. It is something.

[0005] However, the conventional shock sensor is provided in a space required for a driving operation or a position that does not affect the livability of a driver or a fellow passenger, for example, in an automobile. With respect to this installation position, only the shock detection unit 70 is separated from the sensor main body 60 and is so-called “external”, and is set to a minimum size, and any desired position in the car, for example, where a shock can be easily detected. Although the detection accuracy would be improved if it is installed in the, there is a problem that this cannot be easily realized.

That is, for example, if the lead wire to the shock detection unit 70 is made longer than 50 cm, noise is generated in the lead wire itself, and the electrical output of the piezoelectric element is attenuated in the lead wire. , The level required for signal processing cannot be obtained. For this reason, there is a problem that a new amplifier and its power supply are required to amplify the electric output.

In this case, if an amplifier and a power supply are provided, the size of the shock detecting unit 70 is not so different from that of the sensor main body 60. It becomes impossible to provide the impact detection unit 70 at the position.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has an impact detecting unit provided externally to a sensor main body so that the impact detecting unit is located at an arbitrary position away from the sensor main body. It is an object of the present invention to provide an impact sensor which can be installed, and in which a plurality of impact detection units are connected to the sensor main body and which can obtain a detection signal regardless of the installation position.

[0009]

According to one aspect of the present invention, there is provided a shock sensor comprising a shock detecting means, a warning means, a power supply, and a CPU. Wherein the shock detecting means is externally attached to the sensor main body 10, and an electrical output of the shock detecting means is input to the CPU 13 via a low-noise low-attenuation signal line. I do. With the above-described configuration, the electric output is hardly attenuated by the shock detecting means in the low-noise low-attenuation signal line.

[0010] The impact sensor according to claim 2 of the present invention comprises:
Since the two-core shielded wire 30 is used as the low-noise and low-attenuation signal line, connection with a lead wire and wiring as an impact sensor are easy from the viewpoint of flexibility and the like.

[0011] The shock sensor according to claim 3 of the present invention comprises:
Since the shock detecting means is constituted by the vibrating body 20 using the piezoelectric element 21, mechanical vibration due to a shock is converted into an electric signal with high accuracy and high efficiency.

An impact sensor according to a fourth aspect of the present invention is
A plurality of impact detection means, alarm means, power supply 12, CP
U13, wherein at least one impact detecting means is external to the sensor main body 10, and an electrical output of the at least one impact detecting means is low noise and low attenuation. CPU 13 via signal line
It is characterized by being input to. With the configuration described above,
An impact can be detected at any position where the impact detection means is provided.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

Embodiment 1 In this embodiment, as shown in FIG. 1, the impact sensor includes an impact detection unit 25 as impact detection means, an alarm means, a power supply 12, and a CPU 13. The shock detection unit 25 is configured to be externally attached away from the sensor body 10, and the electrical output of the shock detection unit 25 is input to the CPU 13 via the low-noise low-attenuation signal line 30. . Hereinafter, the main components and the low-noise low-attenuation signal line 30 will be sequentially described.

First, the main part of the impact detecting section 25 is constituted by the same piezoelectric element 21 as in the prior art. That is, the piezoelectric element 21 provided with the vibrating weight 22 is fixed on the substrate 23, and the lead wire 25 for picking up the electrical output of the piezoelectric element 21 generated by the mechanical vibration due to the impact is connected to the electrode of the piezoelectric element 21 (FIG. (Not shown).

The piezoelectric element 21 has electrodes (not shown) on both sides of a piezoelectric ceramic plate 21a made of, for example, lead zirconate titanate having a diameter of about 12 mm and a thickness of about 0.3 mm as shown in FIG. The ceramic plate 21a is bonded to the metal plate 21b. The vibrating body 22 is formed by connecting the vibrating weight 22 to the piezoelectric element 21, and the vibrating body 20 is fixed on the substrate 23 via the mounting member 24 so as to maintain a predetermined distance from the substrate 23. Have been.

The piezoelectric element 21 generates an electrical output by electromechanical conversion with respect to mechanical vibration caused by impact.
As described above, by using the piezoelectric element 21, mechanical vibration can be converted into an electric signal with high accuracy and high efficiency, and the alarm means and the like can be controlled using the electric signal.
Shock detector 25 composed of vibrator 20, substrate 23 and mounting member 24
However, it is preferable because it can be reduced in size and its acquisition and assembly are easy.

The vibrating weight 22 is, for example, a metal cylinder 22 having a diameter of about 4 mm and a length of about 17 mm as shown in FIG.
A metal block 22b having a diameter of 5 mm and a thickness of about 5 mm is joined to a, and the vibrating weight 22 is directly attached to the piezoelectric element 21 and joined. Then, the vibrating weight 22 amplifies the above-described mechanical vibration to facilitate the vibration detection by the piezoelectric element 21.

That is, when the piezoelectric element 21 is used alone, sufficient sensitivity to vibration frequency vibrations in the thickness direction can be obtained, but sensitivity to vibration frequencies in other directions is slightly insufficient. And the required detection sensitivity is obtained irrespective of the vibration direction. In this manner, the vibrating weight 22 can amplify the mechanical vibration of the piezoelectric element 21 and is preferable.

For this reason, the size and weight of the vibrating weight 22 are appropriately set according to the magnitude of the impact to be detected. As such a metal material, for example, brass or the like can be used, and the shape, weight, etc. can be arbitrarily set, and can be manufactured with high precision and at low cost by various processing methods such as shaving or press molding. preferable.

Next, the substrate 23 is a substrate made of glass epoxy or the like, and is attached to the substrate 23 by an attaching member 24 for fixing and attaching one end of the vibrating body 20. The mounting member 24
Is a rigid material that freely generates vibrations in the vibrating body, and is made of synthetic resin, metal, or the like.

As described above, in the present embodiment,
The shock detection unit 25 is configured by using the piezoelectric element 21 or the like, but other principles such as detecting a shock by a method using an electromotive force generated when a conductor moves in a magnetic circuit in a direction to cut off magnetic flux are used. May be used to configure the impact detection unit.

Next, a low noise and low attenuation signal line according to the present invention will be described. As the low-noise and low-attenuation signal line, a signal line having low conductor resistance, low crosstalk between signal lines, high insulation resistance of an insulator, and good shielding properties can be used. Specifically, a two-core shielded wire 30, a coaxial cable, and the like are given as examples.

In this embodiment, for example, as shown in FIG. 3, a two-core lead wire 31a and 31b is connected to a conductor having a conductor resistance of about 250 Ω / km and an insulation resistance of an insulator covering this conductor. 1000 MΩkm, the capacitance of this insulator is about 1
A two-core shielded wire 30 having a shield 32 of 10 pF
The lead wire is configured using the
It is connected to the piezoelectric element 21 via 26.

In this embodiment, the aforementioned piezoelectric element
21, the impact weight is configured using the vibrating weight 22, the two-core shielded wire 30, etc., so that the disposition length of the two-core shielded wire 30 is about 4 m.
Even if the length is longer, the required sensitivity level can be maintained without lowering the impact detection sensitivity due to the piezoelectric element 21. Therefore, the impact detecting means can be arranged at an arbitrary position by lengthening the two-core shielded wire 30 in this way.

The two-core shielded wire 30 has a moderate flexibility, and is easy to connect to the piezoelectric element 21 via the lead wire 26 and to wire the shock sensor as a whole. In this case, it is easy to assemble the impact sensor.

Finally, other components will be described.
The CPU 13 receives the electric signal from the piezoelectric element 21 and controls the alarm unit to emit an alarm sound. In the present embodiment, when a small speaker 14 or the like is provided and the piezoelectric element 21 detects an impact, the user is notified of the detection.

Since the speaker 14 is used in this way, even when the user is driving, there is no need to look at the display and the user can be notified without any trouble. In addition, a display device may be provided and displayed, and even if the warning sound is overlooked, the warning sound can be surely recognized.

The power supply 12 drives the CPU 13 and alarm means. In the present embodiment, since a small battery of 12 V is mounted, the sensor main body 10 can be made small and a power cord is not required, so that there is little restriction on a mounting place of the sensor main body 10. In addition, a power source such as a battery of an automobile can be shared, and there is almost no need for care such as consumable replacement as compared with the small battery.

[0030] In the two embodiments the embodiment, as shown in FIG. 4, a plurality of impact detecting means 20 _1, ..., provided a plurality of 20 _n, at least one impact detection means, Externally attached to the sensor body 10,
The electrical output of these impact detection means is configured to be input to the CPU 13 via a low noise and low attenuation signal line. With this configuration, the impact detecting means can be provided at a plurality of locations, the impact can be detected at any position where it is provided, and the impact can be reliably detected and notified irrespective of the location where the impact occurred.

In the structure of the present embodiment, a detection signal comparing means and an impact position display means are further added to the sensor body, and the detection signal comparing means compares the detection signals of the plurality of impact detecting means with each other. The impact position can be specified, and the specified impact position can be displayed on the impact position display means. Therefore, the impact can be reliably detected regardless of the magnitude and location of the impact, and a measure corresponding to the location where the impact occurred can be taken immediately.

In the first and second embodiments described above, the shock sensor according to the present invention has been described in accordance with an example in which the shock sensor is disposed in an automobile. Embodiment 1 or 2 can be easily arranged and used for utilities for
The same effect can be obtained.

[0033]

In the shock sensor according to the present invention, the shock detecting means is externally attached to the sensor body in the shock sensor, and the electrical output from the shock detecting means is input to the CPU via the low noise and low attenuation signal line. With the configuration, the electric output is not attenuated by the shock detecting means in the low-noise and low-attenuation signal line. Accordingly, the length of the low-noise and low-attenuation signal line can be increased, and the impact detecting means can be disposed at an arbitrary position.

When a two-core shielded wire is used as the low-noise low-attenuation signal line, connection with a lead wire and wiring as an impact sensor are easy from the viewpoint of flexibility and the like.
Easy to assemble the impact sensor.

Further, when the shock detecting means is constituted by a vibrating body using a piezoelectric element, mechanical vibration can be converted into an electric signal with high accuracy and high efficiency, and the alarm means and the like are controlled using the electric signal. can do.

The impact sensor according to the present invention is a shock sensor comprising a sensor body having a plurality of impact detection means, wherein at least one impact detection means is external to the sensor body, and the at least one impact detection means is provided outside the sensor body. The electric output by the shock detecting means of the C is transmitted through a low noise and low attenuation signal line.
With the configuration that is input to the PU, the impact can be detected at any position where the impact detection means is provided, and the impact can be reliably detected and notified regardless of the location where the impact occurred.

[Brief description of the drawings]

FIG. 1 is a block diagram of an impact sensor according to an embodiment of the present invention.

FIG. 2 is a perspective view schematically showing a configuration of an impact detection unit according to the embodiment of the present invention.

FIG. 3 is a perspective view showing a configuration of a two-core shielded wire according to one embodiment of the present invention.

FIG. 4 is a block diagram of an impact sensor according to another embodiment of the present invention.

FIG. 5 is a block diagram showing an example of a conventional impact sensor.

[Explanation of symbols]

10 sensor body, 20 vibrator, 21 piezoelectric element, 22 vibrating weight, 30 core shielded wire

Claims (4)

[Claims] An impact detecting means, an alarm means, and a power supply (12)
And an impact sensor comprising a sensor body (10) including a CPU (13), wherein the impact detecting means is a sensor body (10).
A shock sensor, wherein an electrical output of the shock detection means is input to the CPU (13) via a low-noise and low-attenuation signal line. 2. The shock sensor according to claim 1, wherein a two-core shielded wire is used as the low-noise low-attenuation signal line. 3. The shock sensor according to claim 1, wherein said shock detecting means comprises a vibrating body (20) using a piezoelectric element (21). 4. A plurality of impact detection means, an alarm means,
An impact sensor comprising a sensor body (10) including a power supply (12) and a CPU (13), wherein at least one impact detecting means is externally attached to the sensor body (10), and An electrical output from the impact detecting means is input to the CPU (13) via a low-noise low-attenuation signal line.