JP7104946B2 - Vibration sensor, vibration sensor unit, and detection axis configuration change method - Google Patents

Description

The present invention relates to a vibration sensor, a vibration sensor unit, and a detection axis configuration changing method, and more particularly to a method for changing the detection axis of a vibration sensor.

A vibration sensor is a sensor that detects vibration of a railway vehicle or the like during running and acceleration of the vibration. For example, by quickly detecting abnormal vibrations due to a collision accident or the like, it is possible to immediately brake the power system or activate an airbag. For example, the semiconductor acceleration sensor disclosed in Japanese Patent Laid-Open No. 2002-200001 has a silicon substrate formed with a constricted weight portion, a detection wiring formed thereon, and a magnet disposed above the substrate separated from the detection wiring, It is a configuration in which a permanent magnetic field is formed by a magnet around the detection wiring. Vibration acceleration is measured based on changes in the permanent magnetic field caused by external vibration, the resistance value of the detection wiring, and the current.

Further, in Patent Document 2, a detection coil is wound around a central column of a T-shaped yoke, bar-shaped magnets are erected at both ends of the yoke, and a diaphragm is stretched over the central column and two magnets to form a magnetic sensor. An acceleration sensor having a structure in which a body-made weight plate is attached is disclosed. With this configuration, when the weight plate vibrates up and down due to external vibration, the magnetic flux around the weight plate changes and a periodic voltage is induced in the detection coil, and the vibration acceleration of the external vibration is measured based on this electromotive force. It is possible.

Japanese Unexamined Patent Publication No. 9-203748 "Semiconductor Acceleration Sensor" Japanese Unexamined Patent Publication No. 8-5655 "Acceleration sensor"

Now, in a vibration sensor, the direction (axis) of vibration to be detected may be important. For example, when it is desired to detect vibration in the traveling direction of a railroad vehicle, to detect vibration in the lateral direction (perpendicular to the traveling direction), or to detect both. However, with conventional vibration sensors, it was necessary to change the type of vibration sensor in order to change the detection axis.

FIG. 6 is a side sectional view showing the structure of a conventional vibration sensor. FIG. 7 is an explanatory diagram showing a configuration example of a vibration sensor unit using the vibration sensor of FIG. FIG. 7 shows three types of vibration sensor units 610 and the like each including the vibration sensor 62 and the like and the amplifier circuit 66 and the like. As shown in FIG. 6, a conventional vibration sensor 62 is constructed by providing a piezoelectric element 63 in a support 64 . Since the piezoelectric element 63 is provided with an inclination of 0° in the vibration sensor 62, it detects acceleration in the horizontal direction, but cannot detect acceleration in the vertical direction. In other words, since it has sensitivity only in the horizontal direction, the only possible output is the horizontal acceleration output.

Therefore, in the conventional vibration sensor unit 610 or the like, when it is desired to detect vertical acceleration or both of this and horizontal acceleration, that is, when changing the detection axis, it is necessary to change the type of vibration sensor, change the mounting pattern, or It is necessary to change the circuit constants. Depending on the product configuration, it may not be possible to change the detection axis, or the cost may be considerably high.

Therefore, the problem to be solved by the present invention is to eliminate the problems of the prior art, and to provide a vibration sensor capable of changing and selecting the detection axis without changing the type, mounting pattern, and circuit constants of the vibration sensor. and to provide a vibration sensor unit.

As a result of studying the above problem, the inventors of the present application found that it is possible to obtain a configuration in which two vibration sensors of a single specification are used, and the detection axis can be easily selected by combining the direction of arrangement and connection. Based on this, the present invention has been completed. That is, the inventions claimed in the present application, or at least the inventions disclosed as means for solving the above problems, are as follows.

[1] A vibration sensor unit formed by connecting two single-specification vibration sensors, wherein the piezoelectric element has an inclination within the vibration sensor so that the vibration sensor has sensitivity in the horizontal and vertical directions. By changing the combination of the arrangement direction of the two vibration sensors and the connection relationship between the two vibration sensors, vertical axis detection, horizontal axis detection, or vertical + horizontal axis detection can be performed without changing circuit constants. A vibration sensor unit characterized in that any pattern of detection is possible .
[ 2 ] The vibration sensor unit according to [1] , wherein the inclination is 40° or more and 50° or less.
[ 3 ] The vibration sensor unit according to any one of [1] and [2], characterized by comprising a wired amplifier circuit.

[4] The vibration sensor unit according to any one of [1], [2], and [3], which is used for monitoring the condition of railway vehicles.
[ 5 ] A vibration sensor for constituting the vibration sensor unit according to any one of [1], [2], [3], and [4] , wherein the internal piezoelectric element tilts within the vibration sensor. A vibration sensor, characterized in that it comprises:
[ 6 ] In the vibration sensor unit according to any one of [1], [2], [3], and [4] , the combination of the arrangement direction of the two vibration sensors and the connection relationship between the two vibration sensors is A method for changing the configuration of a detection axis in a vibration sensor unit, characterized in that any pattern of vertical axis detection, horizontal axis detection, or vertical + horizontal axis detection is possible without changing circuit constants. .

Since the vibration sensor, the vibration sensor unit, and the detection axis configuration changing method of the present invention are configured as described above, according to these, the vibration sensor type, mounting pattern, and circuit constants can be changed more easily. , the detection axis can be changed and selected. The vibration sensor unit and the like of the present invention are particularly useful for monitoring the condition of railway vehicles .

1 is a side sectional view showing the structure of a vibration sensor according to the present invention; FIG. FIG. 2 is an explanatory diagram showing a configuration example of a vibration sensor unit using the vibration sensor of FIG. 1; FIG. 4 is an explanatory diagram showing a configuration example of a detection axis in the vibration sensor unit of the present invention; FIG. 4 is an explanatory diagram showing vibration excitation directions in the Z-axis detection type vibration sensor unit in FIG. 3 ; 5 is a graph showing the sensitivity of each axis in the same Z-axis detection type vibration sensor unit. FIG. 10 is a side cross-sectional view showing the structure of a conventional vibration sensor; FIG. 7 is an explanatory diagram showing a configuration example of a vibration sensor unit using the vibration sensor of FIG. 6;

The present invention will be described in detail below with reference to the drawings.
FIG. 1 is a side sectional view showing the structure of a vibration sensor according to the present invention. FIG. 2 is an explanatory diagram showing a structural example of a vibration sensor unit using the vibration sensor of FIG. FIG. 2 shows three types of vibration sensor units each composed of a vibration sensor and an amplifier circuit. As shown in these drawings, the vibration sensor unit 5 of the present invention is composed of two single-specification vibration sensors 2 connected together, and the vibration sensors 2 are configured to have sensitivity in the horizontal and vertical directions. is the main configuration. Note that the vibration sensor 2 is configured by providing a piezoelectric element 3 in a support 4 . Further, the structure having sensitivity in the horizontal direction and the vertical direction is specifically a structure in which the piezoelectric element 3 of the vibration sensor 2 is formed with an inclination within the vibration sensor 2 .

With such a configuration, the vibration sensor 2 according to the present invention has sensitivities in the horizontal direction and the vertical direction, and the acceleration output is output as the combined sum thereof. in short;
Output = vertical acceleration output + horizontal acceleration output. The vibration sensor unit 5 of the present invention uses the two vibration sensors 2 having such a configuration, and by changing the combination of the arrangement direction and wire connection, it is possible to select the detection axis. Any pattern of vertical axis detection, horizontal axis detection, and vertical + horizontal axis detection can be constructed using the vibration sensor 2 having exactly the same specifications. A specific example will be described later with reference to FIG.

The tilt angle of the piezoelectric element 3 in the vibration sensor 2 is arbitrary as long as it has sufficient sensitivity in the horizontal and vertical directions, but is preferably 40° or more and 50° or less, or 45° as shown in the figure. can be done. In the present invention, a vibration sensor unit having a configuration in which two vibration sensors 2 and the like are connected is referred to as a vibration sensor unit 5 and the like, and a vibration sensor unit including a connected amplifier circuit 6 and the like is referred to as a vibration sensor unit 10 and the like. .

As described above, in the vibration sensor unit of the present invention, the detection axis can be changed without changing the circuit constant by changing at least one of the arrangement direction of the two vibration sensors or the connection relationship between the two vibration sensors. 3A and 3B are explanatory diagrams showing an example of a configuration of detection axes in the vibration sensor unit of the present invention. The figure (table) summarizes the presence or absence of sensitivity when vibrating in the Z, Y, and X directions in each of the differences in the detection axis due to the arrangement/connection method of the vibration sensor.

In order to obtain the desired detection axis type, it is only necessary to change the orientation of the two vibration sensors and the connection relationship, as shown in this figure. Each of these will be described below.
<1> When using only one vibration sensor (individually) The detection axis is the Z/Y axis. That is, it has sensitivity to both Z-axis excitation and Y-axis excitation. It has no sensitivity to X-axis excitation.
<2> Two vibration sensors are used, arranged in reversed phase, and the wiring method is "cross" in which both + and - are connected.
The detection axis is the Z-axis. That is, it has sensitivity to Z-axis excitation, but does not have sensitivity to Y-axis excitation. It has no sensitivity to X-axis excitation.

<3> Two vibration sensors are used, arranged in opposite phase, and connected in parallel by connecting + and - of both.
The detection axis is the Y-axis. In other words, it has sensitivity to Y-axis excitation, but does not have sensitivity to Z-axis excitation. It has no sensitivity to X-axis excitation.
<4> Two vibration sensors are used, arranged in the same phase, and connected in parallel.
The detection axis is the Z/Y axis. That is, it has sensitivity to both Z-axis excitation and Y-axis excitation. It has no sensitivity to X-axis excitation.

<5> Two vibration sensors are used, arranged in the same phase, and connected in a "cross" manner.
There is no detection axis (non-detection). That is, it has no sensitivity to either Z-axis excitation or Y-axis excitation. In addition, it has no sensitivity to X-axis excitation.

FIG. 4 is an explanatory diagram showing the direction of excitation in the Z-axis detection type vibration sensor unit (<2>) in FIG. (a) is a side view, and (b) is a plan view.
FIG. 5 is a graph showing the sensitivity of each axis in the same Z-axis detection type vibration sensor unit. From the figure, it can be confirmed that the Z-axis, which is the main axis, has good sensitivity, while the other axes, the Y-axis and the X-axis, have almost no sensitivity.

The vibration sensor itself in which the piezoelectric element inside is formed with an inclination, which can constitute the vibration sensor unit described above, is also within the scope of the present invention. Further, in the vibration sensor unit, by changing at least one of the arrangement direction of the two vibration sensors or the connection relationship between the two vibration sensors, the detection axis can be changed without changing the circuit constant. is also within the scope of the present invention.

According to the vibration sensor, the vibration sensor unit, and the detection axis configuration changing method of the present invention, the detection axis can be changed and selected more easily without changing the type, mounting pattern, or circuit constant of the vibration sensor. . Therefore, the invention has high industrial applicability in the field of manufacturing vibration sensors, the field of vibration sensor application such as condition monitoring of railway vehicles, and all related fields, including shaft temperature vibration sensors.

2, 2b, 2c Vibration sensor 3 Piezoelectric element 4 Support 5, 5b, 5c Vibration sensor unit 6, 6b, 6c Amplifier circuit 10, 10b, 10c, 310 Vibration sensor unit (including amplifier circuit)
62, 62b, 62c Vibration sensor 63 Piezoelectric element 64 Support 66, 66b, 66c Amplifier circuit 610, 610b, 610c Vibration sensor unit

Claims (6)

A vibration sensor unit comprising two single-specification vibration sensors connected together, wherein a piezoelectric element is formed with an inclination within the vibration sensor so that the vibration sensor has sensitivity in the horizontal and vertical directions. cage,
Any pattern of vertical axis detection, horizontal axis detection, or vertical + horizontal axis detection can be achieved without changing the circuit constant by changing the combination of the arrangement direction of the two vibration sensors and the connection relationship between the two vibration sensors. A vibration sensor unit characterized in that it is also possible to 2. The vibration sensor unit according to claim 1 , wherein said inclination is 40[deg.] or more and 50[deg.] or less. 3. The vibration sensor unit according to claim 1, further comprising a wired amplifier circuit. 4. The vibration sensor unit according to claim 1 , wherein the vibration sensor unit is used for condition monitoring of railway vehicles. A vibration sensor for constructing the vibration sensor unit according to any one of claims 1 , 2, 3, and 4 , wherein the piezoelectric element inside is formed with an inclination within the vibration sensor. A vibration sensor, characterized by: 5. In the vibration sensor unit according to claim 1 , the circuit constant can be changed by changing the combination of the arrangement direction of the two vibration sensors and the connection relationship between the two vibration sensors. A detection axis configuration change method in a vibration sensor unit, characterized in that any pattern of vertical axis detection, horizontal axis detection, or vertical + horizontal axis detection is possible without requiring.

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