JPH09280941A - Vibration detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration detector which prevents response to fine vibration, noise-like vibration or impact by canceling them intrinsically undesired to be detected in an apparatus to detect the presence of mechanical vibration or impact such as seismic vibration. SOLUTION: A steel ball 2 is movably housed freely in a case 1 and when the steel ball 2 is displaced relatively according to mechanical vibration applied from outside, a switch part provided at a specified layout generates an ON or OFF output according to this displacement. A magnet 4 is provided in the case 1 at a proper layout and exerts an attraction force to the steel ball 2 in a neutral state where no vibration is applied to restrain the movement thereof. As a result, initial mobile response of the steel ball 2 is variably controlled to vibration. A means is provided to variably adjust a magnetic attraction force exerted to the steel ball 2 (by providing a core part 3 for variably adjusting position, variably adjusting the position of the magnet 4, replacing the magnet 4, employing an electric magnet or the like) to accomplish the adjustment of the sensitivity of response.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting the presence or absence of mechanical vibration or shock such as earthquake motion, and more particularly to a device for detecting the presence or absence of vibration or shock of a predetermined amount or more.

[0002]

2. Description of the Related Art An electrodynamic vibration sensor is known which detects vibration by converting mechanical vibration into an electric signal by the principle opposite to that of a voice coil of a speaker. A piezoelectric vibration sensor is known to detect mechanical strain applied to a piezoelectric element as vibration.

[0003]

Conventionally known electrodynamic vibration sensors use a spring to exclusively pick up vibrations in one direction, and complex vibrations in multiple lateral and vertical directions such as seismic motions. The phenomenon could not be detected. Further, although it is possible to prevent the vibration from exceeding a certain level due to the inertia of the spring, this can also only respond to a certain direction, and the accuracy is poor. On the other hand, since the piezoelectric vibration sensor uses a piezoelectric element itself as a spring element, it has a high natural frequency and is hardly damped. Therefore, it is completely unsuitable for vibration detection such as earthquake motion. In any case, the conventional vibration detection device has a large number of malfunctions because of insufficient countermeasures for canceling the small vibration or noise-like vibration that should not be detected and not responding to it. Therefore, when an earthquake motion is detected and, for example, an automatic system is configured to automatically tighten the gas cylinder main plug, when a conventional vibration detection device is used, a vibration other than the earthquake motion is erroneously detected and malfunctions. There was a problem to do. The present invention has been made in view of the above points, and in a device that detects the presence or absence of mechanical vibration or shock such as seismic motion, cancels vibration or shock that is essentially unnecessary to detect and responds to it. The present invention intends to provide a vibration detection device that does not.

[0004]

A vibration detecting device according to the present invention includes a main body, a movable magnetic body arranged so as to be relatively movable with respect to the main body according to gravity, and a predetermined portion in the main body. And a switch part that produces an on or off output according to the relative position of the movable magnetic body part with respect to the main body part, and the movable magnetic part with respect to the main body part in response to mechanical vibration applied from the outside. In a vibration detecting device that obtains the ON or OFF output according to the relative displacement of the body part, the magnetic field generation part provided in the main body part is arranged in a contactless proximity to the movable magnetic body part in a neutral state. Further, it is characterized in that the movable responsiveness of the movable magnetic body portion to the mechanical vibration is controlled by an attractive force generated by the magnetic field generated by the magnetic field generating portion.
When there is no vibration or no impact, the movable magnetic body portion is positioned in a predetermined neutral state by its own weight. The magnetic field generating section may be, for example, a permanent magnet or an electromagnet, and is provided in the main body section in a non-contacting proximity to the movable magnetic body section in the neutral state. With this configuration, the movable magnetic body portion is attracted by the attractive force of the magnetic field generated by the magnetic field generation portion, and the movable responsiveness of the movable magnetic body portion to mechanical vibration applied from the outside is controlled. That is, by attaching the magnetic field generator to a predetermined position of the main body, the magnetic force of the magnetic field suppresses the free movement of the movable magnetic body to some extent. Even if it is added from the above, the movable magnetic body part does not easily move due to the attraction force of the magnetic field generated by the magnetic field generation part, and such minute vibrations or noise-like vibrations or shocks are canceled so as not to respond to it. It has an excellent effect that it can be done.

Adjusting / controlling the magnitude of the force that suppresses the free movement of the movable magnetic body by attaching or detaching the magnetic field generator, or by replacing it with a magnetic field generator that generates a different magnetic force. You can More preferably, it further comprises means for adjusting the strength of the magnetic force exerted on the movable magnetic body portion by the magnetic field generation portion. Various examples of such adjusting means can be designed. When the magnetic field generation unit is a permanent magnet, a magnetic body core portion for deriving the magnetic field is provided, and the arrangement of the magnetic body core portion is variably adjusted by an appropriate means such as a screw so that the magnetic body core portion By variably adjusting the protrusion amount (that is, the gap amount) of the one end portion with respect to the movable magnetic body portion, the strength of the magnetic force exerted on the movable magnetic body portion can be adjusted. Alternatively, the strength of the magnetic force exerted on the movable magnetic body portion can be adjusted by variably adjusting the arrangement itself of the magnetic field generation unit (for example, a permanent magnet) by an appropriate means such as a screw. Alternatively, if the magnetic field generation unit is configured by an electromagnet, the intensity of the magnetic force exerted on the movable magnetic body unit can be adjusted by variably adjusting the exciting current.

Therefore, if the present invention is defined according to another aspect, a vibration detecting device according to the present invention comprises a main body portion and a movable magnetic body portion arranged so as to be movable relative to the main body portion in accordance with gravity. , The permanent magnet provided in the main body, and the position thereof is adjustable in a magnetic field generated by the permanent magnet, and one end of the permanent magnet is close to the movable magnetic body part with a gap, and the gap is adjusted by this position adjustment. A magnetic body core portion capable of adjusting the attractive force of the magnetic field of the permanent magnet with respect to the movable magnetic body portion by variably adjusting the distance between the movable body portion and the main body portion; A switch section for generating an on or off output in accordance with the relative position of the movable magnetic body section, and the switch for the main body section in response to mechanical vibration applied from the outside. It is obtained so as to obtain the ON or OFF output depending on the relative displacement of the magnetic body. As a result, as described above, by adjusting the position of the magnetic body core portion, the gap amount of the one end portion of the magnetic body core portion with respect to the movable magnetic body portion is variably adjusted, and the magnetic force exerted on the movable magnetic body portion is adjusted. You can adjust the strength.

When the present invention is further defined according to another aspect, a vibration detecting device according to the present invention includes a main body portion, a DC magnetic field generating portion provided in the main body portion, the magnetomotive force being adjustable, and the DC magnetic field generating portion. In the magnetic field generated by, is arranged so as to be movable relative to the body portion according to gravity,
A movable magnetic body part to which a braking force is added according to the magnetic force of the magnetic field and a predetermined arrangement in the main body part, and ON or OFF output depending on the relative position of the movable magnetic body part to the main body part And a switch unit for generating the ON or OFF output according to a relative displacement of the movable magnetic body unit with respect to the main body unit caused by a mechanical vibration applied from the outside. As a result, as described above, the strength of the magnetic force exerted on the movable magnetic body portion can be adjusted by adjusting the electromotive force of the DC magnetic field generator.

In one embodiment, the main body section includes a concave curved case made of a non-magnetic material, and the movable magnetic body section is a spherical body rotatably housed in the case. Good. In another embodiment, the movable magnetic body portion may be provided in a pendulum shape in the main body portion. The present invention is applicable not only to repetitive vibrations but also to instantaneous shocks and tilt detection above a certain level, and the term "impact" or "tilt" is included in the category of mechanical vibration in the present invention. Is also included.

[0009]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic vertical cross-sectional view showing an embodiment of the vibration detecting device of the present invention. The concave curved case 1 (that is, the main body) made of a non-magnetic and non-conductive material has a partial spherical shape like a bowl, for example. The top of the case 1 may be covered or covered as appropriate. In the case 1, a steel ball 2 made of a magnetic material such as iron is housed, and the steel ball 2 is movable in the case 1 according to gravity. Therefore, when there is no vibration, as shown in the figure, the steel ball 2 is positioned at the bottom of the case 1 by its own weight, and this position of the steel ball 2 is the neutral position. A permanent magnet 4 is fixedly or semi-fixedly arranged on the lower surface of the outside of the case 1 with an appropriate amount of gap, and in the magnetic field generated by the permanent magnet 4, the magnetic core portion 3 is screw Alternatively, it is arranged so that the position can be adjusted via other appropriate means. The tip of the magnetic core portion 3 is close to the movable magnetic portion, that is, the steel ball 2 with a gap. The magnetic core portion 3 arranged in the magnetic field of the permanent magnet 4 is magnetized, and magnetic lines of force are emitted from its tip. Therefore, by variably adjusting the position of the magnetic core portion 3, the distance of the gap formed between the tip of the magnetic core portion 3 and the steel ball 2 is variably adjusted, and the magnetic force applied to the steel ball 2 depends on the gap amount. It is variably adjusted. Thereby, the attraction force exerted on the steel ball 2 by the magnet 4 is variably adjusted,
The movable responsiveness of the steel ball 2 to the mechanical vibration applied from the outside is variably controlled. That is, when the steel ball 2 is attracted to the magnet 4 with a force according to the gap amount, the free movement of the steel ball 2 is suppressed to some extent, and it is possible to detect a slight vibration or noise that is unnecessary. Even if such a vibration is applied from the outside, the steel ball 2 does not easily move, and it is possible to cancel such a slight vibration or a noise-like vibration so as not to respond to it. Here, the boundary vibration condition in which the steel ball 2 starts to move can be variably adjusted by the suction force according to the gap amount. Of course, when the magnetic core portion 3 is formed by a male screw, there is no need to cut a female screw on the magnet itself, and although not particularly shown, an appropriate member provided with a female screw is fixed to the magnet 4, It is only necessary to provide a space that allows the magnetic core portion 3 to pass through.

A switch portion for detecting the relative displacement of the steel ball 2 with respect to the case 1 may be appropriately arranged inside the case 1. For example, as shown in FIG. 2, two electrical contacts 5a and 5b are arranged corresponding to the neutral position of the steel ball 2 at the bottom of the case 1, and the steel ball 2 is located at the neutral position. At this time, the steel ball 2 may contact both contacts 5a and 5b to electrically close the contacts. When the steel ball 2 is displaced relative to the case 1 by a predetermined amount or more due to vibration applied from the outside, the steel ball 2 deviates from the neutral position and does not come into contact with at least one of the contacts 5a, 5b. Is electrically opened. In this way, the switch portion, that is, the electrical contact 5
On / off outputs are generated from a and 5b in accordance with the presence or absence of externally applied mechanical vibration of a predetermined amount or more. The outputs of the contacts 5a and 5b are input to an appropriate processing circuit 6 and are used as an oscillation detection signal for appropriate control and display. It should be noted that FIG. 2 is merely an example, and can be appropriately changed. For example, when two contact points 5a and 5b are provided side by side on the same surface as shown in FIG. 2, since the movable magnetic body part 2 is a sphere, the height (thickness) of the contact points must be set to a certain degree, and the steel ball 2 is compared. The contact-off output will be output after only a slight amount of movement. On the other hand, in order to output the contact-off when the steel ball 2 moves by a relatively large amount,
For example, one contact 5a is provided with an appropriate width to form the case 1
The other contact 5b is provided above the other contact 5b with an appropriate width by an appropriate means, and the steel ball 2 in the neutral position is located between the upper and lower contacts 5a, 5b. It suffices if the contact is made conductive. Then, when the steel ball 2 moves to some extent and comes off from between the upper and lower contacts 5a and 5b, a contact-off output can be obtained.

In the example of FIG. 2, the switch portion, that is, the electrical contacts 5a and 5b are constructed as normally closed contacts.
Not limited to this, it may be configured as a normally open contact. For example, as shown in FIG. 3, the case 1 may include a bottom portion 1a and a lid portion 1b.
The distance between the bottom portion 1a and the lid portion 1b is smaller than the diameter of the steel ball 2 at a position separated from the neutral position by a predetermined distance, and the bottom portion 1a and the lid portion 1b at that position have contact points. 7a and 7b are provided. As a result, when the steel ball 2 is in the neutral position, the contacts 7a, 7b
When the steel ball 2 moves to the contact points 7a, 7b due to vibration, the case 1 is tilted and the contact points 7a, 7b are opened.
The space between b is closed. The configuration of the electrical contact is not limited to this and may be appropriately designed.

As described above, the case 1 and the permanent magnet 4 are integrated so that the steel ball 2 can move freely relative to the case 1. In use,
This detection device is fixedly or semi-fixedly attached to a place or facility where vibration is to be detected by screwing or pasting or other appropriate means. Then, when mechanical vibration (for example, seismic motion) is applied to the detection target place or equipment from the outside, the integrated structure of the detection device including the case 1 and the permanent magnet 4 is vibrated accordingly. Since the movement of the steel ball 2 is regulated or buffered by the attractive force of the magnet 4, the steel ball 2 does not move easily when the vibration applied from the outside is small or is momentary. It is possible to cancel such slight vibrations and noise-like vibrations so that no output corresponding to them is generated. When the vibration applied from the outside is larger than a predetermined value, the steel ball 2 begins to move after the suction by the magnet 4 is shaken out, whereby the ON or OFF output for detecting the vibration from the electrical contact parts (5a, 5b, 7a, 7b) Is obtained. Here, by variably adjusting the position of the magnetic core portion 3, the gap amount is variably adjusted, the attraction force of the magnet 4 exerted on the steel ball 2 is adjusted, and the movement of the steel ball 2 is regulated. The force or cushioning force is variably adjusted. Therefore, it is possible to cancel a noise-like vibration in the light of a detection purpose (for example, seismic vibration detection) and obtain a detection signal that responds more efficiently to a desired vibration.

The means for variably adjusting the position of the magnetic core portion 3 inserted in the magnet 4 is not limited to the screw type as shown in the drawing, but may be appropriately designed such as a slide structure or a latch slide structure. Alternatively, the magnetic attraction force to the steel ball 2 at the neutral position may be variably adjusted by moving the magnet 4 itself without providing the magnetic core portion 3 for deriving the magnetic force line. FIG. 4 is an enlarged cross-sectional view showing an example thereof. A male screw 8a is provided around the cylindrical magnet 4, and a female screw 8b is provided on the lower surface of the case 1. The position can be adjusted to move closer to or further away from. Also in this case, the means for variably adjusting the position of the magnet 4 is not limited to the screw type as shown in the drawing, but may be appropriately designed with a slide structure or a latch slide structure. Also, the permanent magnet 4
The object of the present invention may be achieved by adjusting the permanent magnet to a permanent magnet having a different performance, or removing or installing the permanent magnet depending on the application. FIG. 5 is an enlarged view of an example of the case.
An appropriate attachment / detachment mechanism 9 is provided on the lower surface of, and the permanent magnet 4 is attached or detached via this attachment / detachment mechanism 9 or a permanent magnet having a different magnetic force is appropriately replaced.

The movable magnetic member is the steel ball 2 as in the above embodiment.
However, other suitable structures may be used. FIG.
Shows an example of using a pendulum-like structure as the movable magnetic body part. Above the inside of the non-magnetic and non-conductive case 11, there is provided a conductive support portion 12a forming a first electrical contact, and a pendulum-like movable magnetic body portion with respect to the conductive support portion 12a. An upper sphere 13a of 13 is swingably supported. Pendulum-like movable magnetic body part 13
Is a structure in which the upper sphere 13a and the lower sphere 13c are connected by the arm portion 13b, the lower sphere 13c corresponds to the weight of the pendulum, the whole is a conductor, and at least the lower sphere 13c is made of a magnetic material. For example, iron is a suitable material. A conductive box 12b forming a second electrical contact is provided in the lower part of the case 11, and the pendulum-shaped movable magnetic body part 1 is provided in the box 12b.
The lower sphere 13c of 3 has entered. Output conductors are drawn out from the conductive support portion 12a that is the first electrical contact and the conductive box 12b that is the second electrical contact, and are input to the appropriate processing circuit 6. When the lower sphere 13c of the pendulum-shaped movable magnetic body portion 13 is stationary at the neutral position, the contact is off, and the lower sphere 13c sways in response to vibration to cause the conductive box 12b to move as indicated by the two-dot chain line in the figure. When it comes into contact with the wall surface of the conductive support portion 12a, which is the first electrical contact, the upper sphere 13 of the pendulum-like movable magnetic body portion
The a, the arm portion 13b, the lower sphere 13c, and the conductive box 12b, which is the second electrical contact, are electrically connected to generate a contact-on output.

A permanent magnet 4 is fixedly or semi-fixedly arranged on the lower surface of the outside of the case 11, and in the magnetic field generated by the permanent magnet 4, the magnetic core portion 3 is arranged in the same manner as in FIG. , The position is adjustable via a screw type or other appropriate means. The tip of the magnetic core 3 is
It passes through the case 11 and the wall surface of the box 12b and enters the space inside the box 12b, and is close to the movable magnetic body portion, that is, the lower sphere 13c with a gap. Similarly to the above, the magnetic core portion 3 arranged in the magnetic field of the permanent magnet 4 is magnetized, and the magnetic force lines are emitted from the tip portion thereof. Therefore, by variably adjusting the position of the magnetic core portion 3, the distance of the gap formed between the tip of the magnetic core portion 3 and the sphere 13c is variably adjusted, and the magnetic force applied to the sphere 13c is varied according to the gap amount. Adjusted. As a result, similarly to the above, the attraction force exerted on the pendulum ball 13c by the magnet 4 is variably adjusted, and the movable responsiveness of the pendulum ball 13c to the mechanical vibration applied from the outside is variably controlled.

It is needless to say that an electromagnet may be used instead of the permanent magnet 4 in each of the above embodiments. In that case,
By variably adjusting the exciting current of the electromagnet, the magnetic attraction force exerted on the movable magnetic body portion (steel ball 2 or pendulum ball 13c) can be variably adjusted, so that the magnetic body core portion 3 is not provided. Alternatively, even if provided, the position may not be variably adjusted. Moreover, not only a DC electromagnet but an AC magnetic field generator may be used. In addition, the movable magnetic body portion (steel ball 2) in case 1
Alternatively, the switch unit for detecting that the position of the pendulum ball 13c) is relatively displaced is not limited to the above-described electrical contact that responds to the presence or absence of contact of the movable magnetic body unit, and other appropriate ON -Off output generation mechanism may be adopted. For example, an optical detector may be used. The response characteristic to vibration can also be selected by appropriately selecting the mass of the movable magnetic body-for example, not responding to small vibrations but responding to slow and large vibrations. Therefore, it is possible to have a resonance characteristic with respect to a desired seismic wave, so that noise-like vibration can be canceled in light of the detection purpose (for example, seismic wave detection), and the desired seismic wave vibration can be improved. It is also possible to obtain a detection signal that responds.

[0017]

As described above, according to the present invention, the initial movement of the movable magnetic member is suppressed by the attractive force of the permanent magnet or the electromagnet, so that it is possible to prevent unnecessary vibrations and noises. Even if vibration, shock, or inclination is applied from the outside, the movable magnetic body part does not easily move, and it is possible to cancel such minute vibration or noise-like vibration so that it does not respond to it. It has an excellent effect. Further, by variably adjusting the magnetic attraction force exerted on the movable magnetic body portion, it is possible to easily adjust the vibration detection sensitivity, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing an embodiment of a vibration detecting device according to the present invention.

2 is a schematic plan view showing a configuration example of electrical contacts in the detection device of FIG. 1. FIG.

FIG. 3 is a schematic vertical cross-sectional view showing another configuration example of the electrical contacts in the detection device of FIG.

FIG. 4 is a schematic vertical cross-sectional view showing a modified example of the detection device of FIG. 1, showing an example in which the arrangement of magnets can be variably adjusted.

5 is a schematic vertical cross-sectional view showing another modification of the detection device shown in FIG. 1, in which the magnet can be removed or replaced.

FIG. 6 is a schematic vertical sectional view showing another embodiment of the vibration detecting device according to the present invention.

[Explanation of reference numerals] 1,11 Case 2 Steel ball 3 Magnetic core part 4 Permanent magnet 13 Movable magnetic part 5a, 5b, 7a, 7b, 12a, 12b Electrical contact

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Nobuyuki Akazu 2-1453-43, Niibori, Higashiyamato-shi, Tokyo (72) Inventor Kazuya Sakamoto 1-1-5 Kawasaki, Hamura-shi, Tokyo, MAC Hamura Court II- 405 (72) Inventor Hiroshi Sakamoto 896-8 Yamada, Kawagoe-shi, Saitama (72) Inventor Akio Yamamoto 1-13-29 Nishi, Kunitachi-shi, Tokyo KM Heights 101

Claims (6)

[Claims] 1. A main body part, a movable magnetic body part arranged so as to be movable relative to the main body part in accordance with gravity, a movable magnetic body part provided in a predetermined arrangement in the main body part, A switch section that produces an on or off output according to the relative position of the body section, and the on or off state according to the relative displacement of the movable magnetic body section with respect to the main body section in response to mechanical vibration applied from the outside. In a vibration detecting device for obtaining an off output, a magnetic field generating section provided in the main body section is arranged in a non-contact manner in proximity to the movable magnetic body section in a neutral state, and a magnetic field generated by the magnetic field generating section. A vibration detection device, wherein the movable responsiveness of the movable magnetic body part to the mechanical vibration is controlled by the suction force of the. 2. The vibration detecting device according to claim 1, further comprising means for adjusting the strength of the magnetic force exerted by the magnetic field generating section on the movable magnetic body section. 3. A main body, a movable magnetic body arranged so as to be movable relative to the main body according to gravity, a permanent magnet provided on the main body, and a magnetic field generated by the permanent magnet. A magnetic field of the permanent magnet with respect to the movable magnetic body portion by variably adjusting the distance of the gap by this position adjustment. A magnetic core part capable of adjusting the attraction force by the switch, and a switch part provided in a predetermined arrangement in the main body part and generating an on or off output according to the relative position of the movable magnetic body part with respect to the main body part. And a vibration detecting device that obtains the ON or OFF output in accordance with relative displacement of the movable magnetic body portion with respect to the main body portion that occurs in response to mechanical vibration applied from the outside. 4. A main body, a DC magnetic field generator capable of adjusting a magnetomotive force provided in the main body, and in a magnetic field generated by the DC magnetic field generator, relative to the main body according to gravity. A movable magnetic body part that is movably arranged and to which a braking force is applied according to the magnetic force of the magnetic field; and a movable magnetic body part that is provided in a predetermined arrangement in the main body part and is located at a relative position to the main body part. And a switch section for generating an ON or OFF output in response to the vibration detection for obtaining the ON or OFF output according to a relative displacement of the movable magnetic body section with respect to the main body section caused by an externally applied mechanical vibration. apparatus. 5. The main body section includes a concave curved case made of a non-magnetic material, and the movable magnetic body section is a sphere housed in the case so as to be rollable.
The vibration detection device according to any one of 1. 6. The movable magnetic body portion is provided in a pendulum shape in the main body portion.
The vibration detection device according to any one of 1.