JP2002350458A - Falling object detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately and surely detect falling in the whole area of a receiving plate upper surface without generating an insensitive area, and freely discriminate the size of a falling object by the size of the detecting output. SOLUTION: This falling object detecting device has a receiving plate vibratingly supported by butting with the falling object, and an acceleration sensor installed on this receiving plate. The acceleration sensor detects the falling of the falling object on the receiving plate by detecting vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Detailed description of the invention]

[0002]

2. Description of the Related Art In recent years, in order to prevent the occurrence of train accidents caused by the falling of a person from a platform or the falling of articles,
It has been proposed to lay a fallen object detection device along a track under a platform. A so-called mat switch is widely used as such a falling object detection device.

As schematically shown in FIG. 10, a mat switch a is formed by a pair of upper and lower tape-like electrode pairs c facing each other at a small interval inside a rubber-bag-like protective cover b which is airtightly closed. Are arranged in parallel with each other. Then, when pressure is applied in the vertical direction, the upper and lower electrode pieces c1 and c2 facing each other come into contact with each other to be electrically connected, and the presence or absence of a drop is detected. The symbol d is a cushion material for separating the electrode pieces c1 and c2.

[0004]

However, this one is
Since the electrode pair c is accommodated in the protective cover b, a dead area e having a width of, for example, about 4 cm is inevitably formed around the electrode pair c. Therefore, a drop occurring in the dead area e can be detected. There is a problem of disappearing. The protective covering b is made of a flexible material having excellent weather resistance, such as natural rubber, but has a low strength and is susceptible to deterioration due to aging or tobacco fire. The durability is inferior, for example, due to the deterioration of the insulation caused by the penetration of water.

Accordingly, the present invention is based on the fact that a receiving plate for receiving a falling object is supported so as to be able to vibrate and an acceleration sensor is attached to this receiving plate. An object of the present invention is to provide a fallen object detection device that can accurately and surely detect a fallen object, can freely identify the size of a fallen object by the magnitude of its detection output, and can exhibit excellent durability.

[0006]

In order to achieve the above object, an object of the present invention is to provide a receiving plate which receives a dropped object and which is supported so as to be able to vibrate by abutment with the dropped object. An acceleration sensor attached to the plate and detecting the vibration to detect the fall of the falling object onto the receiving plate.

[0007] The invention according to claim 2 is characterized in that the receiving plate is supported by a support means for supporting the receiving plate floating above a road surface.

According to the third aspect of the present invention, the support means includes:
It is characterized in that the receiving plate is supported via elastic means for facilitating vertical vibration of the receiving plate.

According to a fourth aspect of the present invention, the receiving plate is a grating plate.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present invention will be described.
This will be described together with the illustrated example. FIG. 1 is a perspective view showing a falling object detecting device of the present invention, and FIG.

In FIG. 1, a falling object detecting device 1 includes a receiving plate 2 for receiving a falling object, and an acceleration sensor 3 attached to the receiving plate 2, and the acceleration sensor 3 is provided by a collision with the falling object. By detecting the acceleration of the generated vibration of the receiving plate 2, the falling of the falling object onto the receiving plate 2 is detected.

Therefore, it is indispensable that the receiving plate 2 can vibrate by abutment with a falling object. For this purpose, the receiving plate 2 is supported by the leg-like supporting means 4 so as to float from the road surface S.

In order to transmit the vibration of the receiving plate 2 without absorbing the impact with the falling object, the receiving plate 2 is made of, for example, a rigid plate made of metal, wood, ceramic, plastic, or the like. Is formed as This receiving plate 2
Although the size of is not particularly limited, for example, a width of 20 cm and a width of 1 cm
A horizontally long rectangular shape of about 00 cm can be suitably used.

Next, the supporting means 4 are arranged at a plurality of positions on the receiving plate 2 so as to float the receiving plate 2 from the road surface S and support it substantially horizontally. In this example, the support means 4
Is a frame-shaped leg 5 extending in the width direction of the receiving plate 2,
The case where the receiving plate 2 is arranged at three positions, that is, both ends in the longitudinal direction and a central portion thereof is illustrated. It may be arranged only at both ends.

In this supporting means 4, in order to facilitate the vertical vibration of the receiving plate 2, the leg 5 itself is formed of an elastic material such as rubber or hard sponge, for example, as shown in FIG. Can be. For the same purpose, the leg 5 may be formed of a hard inelastic body, and the receiving plate 2 may be supported via elastic means 6 using, for example, a spring.

In the present embodiment, the latter (through the elastic means 6) is adopted from the viewpoints of ease, stability, reliability, strength and the like of the vertical vibration.

More specifically, as shown in an enlarged manner in FIG. 2, the elastic means 6 stands on the leg 5 and guides the receiving plate 2 to be slidable up and down.
And a spring 10 for urging the receiving plate 2 upward.

In the present embodiment, the guide 9 is provided with the receiving plate 2.
Cylindrical guide tube 9A inserted into hole 2A provided in
And a flange 9B projecting in a flange shape at the upper end thereof, and is fixed to the upper surface of the leg 5 via a bolt fitting (including screws) 11 passing through the inside of the guide cylinder 10A.

In the present embodiment, the spring 10 is a wound spring, and is disposed between the upper surface of the leg 5 and the lower surface of the receiving plate 2 and on the outer periphery of the guide tube 9A, so that the receiving plate 2 is raised. Energize and support.

That is, in the present embodiment, the receiving plate 2 can be moved up and down between an upper limit position where it comes into contact with the flange 9B and a lower limit position where the spring 10 is almost in close contact. Supported.

Next, the acceleration sensor 3 detects the acceleration of the vibration of the receiving plate 2 caused by the collision with the falling object, and is, for example, a servo type, a piezoelectric type, a piezoresistive type, a capacitance type. Various known types can be used. The acceleration sensor 3 may be a one-axis type, a two-axis type, or a three-axis type as long as it can detect acceleration at least in the Z-axis direction (vertical direction). The case where a three-axis type is used is illustrated.

The acceleration sensor 3 is protected by a protective case 12 in a waterproof manner, and the receiving plate 2
Attached to the lower surface of the. As the protective case 12, a protective cover b in the conventional mat switch a is used.
It is not necessary to use a flexible material such as rubber as shown in FIG. 10, and it can be formed of a member having excellent strength, durability, weather resistance and the like such as metal and plastic. The mounting position of the acceleration sensor 3 is not particularly limited as long as it is located on the lower surface of the receiving plate 2. In this example, the case where the acceleration sensor 3 is provided between the legs 5 is exemplified.

As described above, since the acceleration sensor 3 is attached to the vibratingly supported receiving plate 2 of the falling object detecting device 1 of the present embodiment, the vibration of the receiving plate 2 caused by the collision with the falling object is detected. Thus, it is possible to detect the fall of the falling object onto the receiving plate 2.

At this time, the accuracy and reliability of the detection can be improved, for example, the falling object can be abutted on the entire upper surface of the receiving plate 2, that is, there is no dead area, and the fall can be detected reliably over the entire upper surface. can do. Further, since only one acceleration sensor 3 is required, the circuit and wiring are simple and a compact design is possible.

In addition, since the size of the falling object can be recognized based on the magnitude of the detection output, it is possible to identify and detect, for example, the difference between the fall of a person and the fall of an article and the size of an article. Appropriate responses can be taken promptly to anticipated accidents.

In order to perform the detection more uniformly over the entire area of the upper surface, it is preferable to support the entire receiving plate 2 vertically slidably via the elastic means 6 as in this embodiment. As a result, it is possible to obtain a uniform acceleration gain without substantially affecting the collision position with the falling object and the attachment position of the acceleration sensor 3, and it is possible to improve the detection uniformity.

In the falling object detecting device 1 of the present embodiment, the receiving plate 2 can be formed of a grating plate 20, as shown in FIG. At this time, because the grating is rough,
For example, it is possible to prevent small animals such as rats from getting on the receiving plate 2 and also to blow off the wind pressure generated by the passing train. Therefore, in addition to the weight reduction, an effect of suppressing erroneous detection due to the wind pressure of the small animal or the train can also be achieved.

It is preferable that a protective cover (not shown) in the form of a rubber sheet be provided on the upper surface of the receiving plate 2 in order to prevent injury (primary disaster) when a person falls. .

In the falling object detecting device 1, the supporting means 4
Is not always necessary, and as shown in FIG. That is, when there is the protruding object 13 on the road surface S, the support means 4 can be eliminated, and the falling object detecting device 1 can be constituted by the receiving plate 2 and the acceleration sensor 3.

Although the preferred embodiment of the present invention has been described in detail above, the present invention is not limited to the illustrated embodiment, but may be implemented in various forms.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A prototype of a fallen object detecting device 1 having the structure shown in FIG. 1 is manufactured, and as shown in FIGS. 6A and 6B, a position A on the acceleration sensor 3 between the legs 5 and 5, and Each of the legs 5 has a weight of 0.
24 kg (umbrella) and weight 6.8 kg (cable package)
Was dropped from a height of 60 cm. At this time, the vibration of the receiving plate 2 measured by the acceleration sensor 3 is shown in FIG.
8 is shown.

As shown in FIGS. 7 and 8, it can be confirmed that the waveform of the vibration changes according to the weight of the falling object without substantially affecting the position of the falling object. In particular, when comparing the waveform of FIG. 7 with the waveform of FIG. 8, the difference in the area between the reference line (voltage 0) and the + side waveform (or the − side waveform) clearly shows the difference due to the weight of the falling object. Represents.

Next, the above-mentioned fall is performed 5 times each,
FIG. 9 shows the maximum value of the vibration at that time. As shown in FIG. 9, similarly, it can be confirmed that the maximum value of the vibration changes according to the weight of the falling object without substantially affecting the position of the falling object.

Therefore, by obtaining the waveform of the vibration by the acceleration sensor 3 and calculating the area between the reference line and the + side waveform, or by obtaining the maximum value of the vibration, not only the presence or absence of the drop but also the The weight itself can be estimated.

[0035]

As described above, according to the present invention, a receiving plate for receiving a falling object is supported so as to be able to vibrate, and an acceleration sensor is attached to this receiving plate.
The fall can be accurately and reliably detected over the entire area of the upper surface of the receiving plate. In addition, the size of the falling object can be freely identified by the magnitude of the detection output. In addition, excellent durability and strength can be exhibited over a long period of time.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a falling object detection device of the present invention.

FIG. 2 is a sectional view showing the supporting means together with an elastic means.

FIG. 3 is a side view showing another example of the support means.

FIG. 4 is a perspective view showing another example of the receiving plate.

FIG. 5 is a schematic view showing another example of the falling object detection device.

FIGS. 6A and 6B are schematic diagrams showing a drop position in a drop test.

FIGS. 7A and 7B show a falling object M1 at positions A and B;
5 is a vibration waveform when dropped.

FIGS. 8A and 8B show a falling object M2 at positions A and B;
5 is a vibration waveform when dropped.

FIG. 9 is a diagram showing the maximum value of vibration when each drop is repeated five times.

FIG. 10 is a cross-sectional view illustrating the structure of a conventional mat switch.

[Explanation of symbols]

 2 receiving plate 3 acceleration sensor 4 support means 6 elastic means

Claims (4)

[Claims] 1. A receiving plate which receives a falling object and is supported so as to vibrate by abutment with the falling object, and is attached to the receiving plate and detects the vibration so that the falling object is transferred to the receiving plate. A fallen object detection device comprising an acceleration sensor for detecting a fall. 2. The fallen object detecting device according to claim 1, wherein said receiving plate is supported by a support means for supporting said receiving plate floating above a road surface. 3. The falling object detecting device according to claim 2, wherein said support means supports said receiving plate via elastic means for facilitating vertical vibration of said receiving plate. 4. The falling object detecting device according to claim 1, wherein said receiving plate is a grating plate.