JPH0843430A - Piezoelectric type vibration sensor and its manufacture - Google Patents

Abstract

PURPOSE:To provide a piezoelectric type vibration sensor wherein a piezoelectric body is small in quantity. CONSTITUTION:A diaphragm vibration board 2 and a detection part 3 which detects vibration of the diaphragm oscillation board 2 are provided. To the detection part 3, with axes orthogonally crossing together on the center of one face of the diaphragm taken as x-axis and y-axis, a pair of band-like x-axis detection parts arranged on the x-axis with the intersection in between, a pair of band-like y-axis detectian parts arrangeed on the y-axis with the intersection in between, and a pair of band-like z-axis detection parts arranged at point- symmetrical position with the intersection between them are provided. These x-axis, y-axis, and z-axis detection parts contain a band-like piezoelectric bodies 10, common electrodes 11 assigned over the entire surface of one side of the piezoelectric bodies 10, and a pair of detection electrodes 12 arranged on the other side surface af the piezoelectric bodies 10, along the longitudinal direction of the piezoelectric bodies 10. Based on the quantity of charge or potential difference produced between each detection electrode 12 and common electrodes 11, vibration is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric vibration sensor using a piezoelectric element as a detection element and a method for manufacturing the same, and more particularly, to detection of vibration of a transportation machine body and detection of vibration and impact applied to various devices. In transport aircraft, it relates to a piezoelectric vibration sensor and its manufacturing method used in various fields such as attitude control, automobile air bag system, equipment diagnosis of equipment, data protection from vibration / shock of computer hard disk. is there.

[0002]

2. Description of the Related Art Piezoelectric vibration sensors of this type are classified into a cantilever type, a double-supported beam type, a compression type, and a
It is classified as a diaphragm type. Among these, a vibration sensor of a type corresponding to a diaphragm type is a sensor that distorts a piezoelectric element by the flexural vibration of a thin diaphragm diaphragm and detects the vibration by the piezoelectric effect of this piezoelectric element.

In this diaphragm type vibration sensor, a vibration sensor that utilizes the deflection of only the diaphragm and a load body at the center of the diaphragm are provided to increase the amount of deflection when subjected to vibration and to increase the sensitivity of the sensor. There is a vibration sensor. As such a diaphragm, there are known one in which a piezoelectric body is used as a diaphragm diaphragm (a) and one in which the piezoelectric body is bonded to the diaphragm diaphragm (b).

A piezoelectric vibration sensor using a diaphragm of (a) uses a uniform piezoelectric body itself as a diaphragm vibration plate, a detection electrode is provided on one surface of the diaphragm vibration plate, and a common electrode is provided on the other surface. Is provided. In this case, since the stress direction is different between the peripheral part and the central part of the diaphragm diaphragm, the sensing electrode is formed in a shape divided into the central part and the peripheral part of one surface, and the common electrode is the other part of the diaphragm diaphragm. Is provided on the entire surface of the diaphragm, and the potential difference between the detection electrodes at the central portion and the peripheral portion of the diaphragm diaphragm is taken out as an output.

A piezoelectric type vibration sensor using a diaphragm of (b) is a diaphragm vibrating plate that controls vibration, and a uniform piezoelectric body is attached to the diaphragm. The piezoelectric vibration sensor is almost equal to the piezoelectric body or has an elastic modulus higher than that of the piezoelectric body. Higher material is used as the diaphragm. In this case, it is preferable to provide the detection electrode and the common electrode on both surfaces of the piezoelectric body because noise due to current collection can be removed in principle.

In the method (b), since the vibration of the diaphragm diaphragm is controlled not by the piezoelectric body but by the diaphragm diaphragm, when a polymer type piezoelectric body or the like whose elastic modulus changes greatly with temperature is used as the sensing element. It is advantageous.

[0007]

However, in any of the above-mentioned piezoelectric vibration sensors using the diaphragm, it is necessary to use a piezoelectric body on one surface of the diaphragm. In the case of this type of vibration sensor, the diaphragm of the diaphragm is used. In many cases, the diameter is set to 1 cm or more, and the cost of the piezoelectric material of the piezoelectric body occupies a large proportion of the material cost of the piezoelectric vibration sensor, and the cost of the piezoelectric vibration sensor increases.

Further, in order to take out the output from the diaphragm, it is necessary to form an electrode directly on the piezoelectric body,
There is also a problem that it takes time to manufacture because it is necessary to connect a lead wire or the like to take out the output from this electrode. Further, when the polymer-based piezoelectric body is used, the heat resistance is poorer than that of the ceramic-based piezoelectric body, so that there is a problem that the electrode formation is restricted.

The present invention effectively solves at least one of the above problems, and an object of the present invention is to provide a piezoelectric vibration sensor capable of reducing the manufacturing cost by reducing the amount of the piezoelectric body, and a manufacturing method thereof. .

[0010]

SUMMARY OF THE INVENTION A piezoelectric vibration sensor of the present invention is a piezoelectric vibration sensor having a diaphragm diaphragm and a detector arranged on one surface of the diaphragm diaphragm for detecting vibration of the diaphragm diaphragm. In the type vibration sensor, the detection unit has a pair of strips arranged on the x-axis across the intersection when the axes orthogonal to the center of one surface of the diaphragm are the intersections. An x-axis detector and a pair of strip-shaped y's arranged on the y-axis across the intersection.
It has an axis detecting section and a pair of band-shaped z-axis detecting sections arranged at point-symmetrical positions with the intersection point therebetween, and these x-axis, y-axis,
The z-axis detection unit is provided on a strip-shaped piezoelectric body, a common electrode arranged over substantially the entire one surface of the piezoelectric body, and the other surface of the piezoelectric body along the longitudinal direction of the piezoelectric body. It is characterized in that it has a pair of detection electrodes that are formed, and detects vibration from the amount of electric charge or the potential difference generated between each of these detection electrodes and the common electrode.

It is preferable that the sensing electrode and an electric circuit connected to the sensing electrode are formed on one surface of the diaphragm diaphragm. The manufacturing method of the present invention is characterized in that the sensing electrode and the electric circuit are provided on one surface of the diaphragm diaphragm in advance, and then the piezoelectric body and the common electrode are provided.

A piezoelectric vibration sensor of the present invention and a method of manufacturing the same will be described below with reference to the drawings. As shown in Figure 1,
Reference numeral 1 denotes a piezoelectric vibration sensor. The piezoelectric vibration sensor 1 includes a diaphragm diaphragm 2 on which an electric circuit is formed by printing, and a detection unit 3 provided on the diaphragm diaphragm 2 and connected to the electric circuit. And a support body 4 that is fixed around the diaphragm diaphragm 2 and supports the diaphragm diaphragm 2.

The shape of the diaphragm diaphragm 2 is not particularly limited and varies depending on the direction of vibration to be detected, the number of detection axes, etc., but any detection axis is different from the diaphragm diaphragm 2 orthogonal to it. By forming a horizontal line segment as a line object, the sensitivity of the other axis can be minimized. Examples of this shape include a circle, a regular polygon, a rectangle, and a rhombus.

The detector 3 has a pair of strip-shaped x's arranged on the x-axis across the intersection, where the axes orthogonal to the center of one surface of the diaphragm 2 are the x-axis and the y-axis. It has an axis detection unit 5, a pair of belt-shaped y-axis detection units 6 on the y-axis across the intersection, and a pair of belt-shaped z-axis detection units 7 arranged at point-symmetrical positions with the intersection therebetween. As shown in FIG. 3, the x-axis detector 5, the y-axis detector 6, and the z-axis detector 7,
A strip-shaped piezoelectric body 10, a common electrode 11 arranged over the entire upper surface of the piezoelectric body, and a detection electrode 12 formed on the upper surface of the diaphragm diaphragm 2 located on the lower surface of the piezoelectric body 11.
And have respectively. These detection electrodes 12 are the piezoelectric body 1.
Pairs are provided in parallel along the longitudinal direction of 0.

In the x-axis detecting section 5 and the y-axis detecting section 6, as shown in FIG. 4, the detection electrodes sandwiching the intersection are connected to each other. Further, in the z-axis detection unit 7, as shown in FIG. 5, a detection electrode near the center of one z-axis detection unit,
The other z-axis detection unit is connected to the outer detection electrode. In the electric circuit connected to these detection electrodes, a signal processing circuit (impedance conversion circuit, amplification circuit, etc.) for processing the signals of the detection electrodes is formed around the diaphragm diaphragm 2.

The material of the diaphragm diaphragm 2 is also not particularly limited, but satisfies the relationship of E _d t ³ _d ≧ 10E _p t ³ _{p with} respect to the partially arranged piezoelectric body 10. By doing so, the vibration of the diaphragm diaphragm 2 can be a constant vibration regardless of the rigidity of the piezoelectric body 10. Here, E _d and E _p represent elastic moduli of the diaphragm diaphragm 2 and the piezoelectric body 10, respectively, and t _d and t _p are
The thicknesses of the diaphragm diaphragm 2 and the piezoelectric body 10 are shown.

The material of the piezoelectric body 10 is not particularly limited, and may be a synthetic resin piezoelectric material such as polyvinylidene fluoride, polyvinyl fluoride, a copolymer of tetrafluoroethylene and trifluoroethylene, or titanium. A ceramic piezoelectric material having a perovskite structure such as an acid metal salt can be used. Here, for a material having a relatively high temperature dependence of the elastic modulus, such as a polymer-based piezoelectric body, by using a ceramic or a metal material having a small temperature dependence of the elastic modulus for the diaphragm diaphragm, It is possible to suppress the temperature dependence to a small level. That is, the material of the piezoelectric body 10 is ceramics, polymer,
Various materials such as a composite material of both can be used.
The size of the piezoelectric body 10 is not particularly limited, either,
High sensitivity can be obtained by arranging not the entire surface of the diaphragm diaphragm 2 but the width, the length and the like.

The support 4 for supporting the diaphragm is made of fiber reinforced resin (FRP) such as glass fiber reinforced epoxy resin obtained by impregnating epoxy resin with glass fiber, and is fixed around the diaphragm 2. The size of the support 4 is not particularly limited, but is formed to have substantially the same shape as the outer shape of the diaphragm diaphragm 2.

Detection of vibration in each axial direction of such a piezoelectric vibration sensor will be described. 1. Operation of Z-axis detection unit (1) When vibration in Z direction is received As shown in FIG. 5, the piezoelectric bodies on the detection electrodes Z11 and Z23 are subjected to stress of the same magnitude in the same direction. Similarly, the piezoelectric bodies on the detection electrodes Z13 and Z21 are also subjected to the same amount of stress in the same direction. The detection electrode Z11 (Z23) and the detection electrode Z13 (Z21) have different stress directions and magnitudes. Therefore, between the sensing electrode and the common electrode, that is,
Between Z11-Z12 (Z23-Z22) and Z13-Z12 (Z21-
(Between Z22), when a certain vibration is applied, a potential difference having different polarities is generated. In this case, the wiring of the Z-axis detection unit can be regarded as equivalent to the case where a certain AC generator is connected in series, so that an output (Vz) can be obtained for a certain vibration. Vz = V (11-12) -V (13-12) + V (23-22) -V (21-22) where V (11-12) = V (23-22), V (13-12) ) = V (21-22) Therefore, Vz = 2V (11-12) -2V (13-12) (V (11-12) and V (13-12) have different polarities.)

(2) When subjected to vibration in the X or Y direction The Z-axis detector is formed point-symmetrically with respect to the intersection of the detection axes. The stress when it is subjected to horizontal vibration has the same absolute value but different polarity at this point-symmetrical position. Therefore, in the wiring of the Z-axis detection unit, between the detection electrode and the common electrode, between Z11 and Z12 and between Z23 and Z22,
Although the absolute values are the same, stresses with different polarities are applied, and therefore the potential differences that occur are canceled out by the same relationship. Similarly, the outputs of the electrodes Z13-Z12 and Z23-Z22 are offset, and as a result, the output (Vz) is offset between the electrodes, resulting in no sensitivity. Vz = V (11-12) -V (13-12) + V (23-22) -V (21-22) where V (11-12) =-V (23-22), V (13- 12) =-V (21
-22) Therefore, Vz = 0

2. Operation of X-axis detection unit (1) When vibration in X direction is received The relationship between this vibration and stress is the same as in 1- (2) above. Therefore, as shown in FIG. 4, between the detection electrode and the common electrode, that is, between X11 and X12 and between X23 and X22, there is a potential difference between the electrodes X13 and X12, although the absolute values are the same but the polarities are different. And the electrodes X21-X22 also generate a potential difference having the same absolute value but different polarities. The output of the wiring of the X-axis detector is obtained as follows. Vx = V (11-12) -V (13-12) + V (21-22) -V (23-22) where V (11-12) =-V (23-22), V (13- 12) =-V (21
-22) Therefore, Vx = 2V (11-12) -2V (13-12) (V (11-12) and V (13-12) have different polarities.)

(2) When receiving vibrations in the Y direction Since the X-axis detecting section is provided on the X-axis, when receiving vibrations in the Y-direction, it is not supported on the support shaft (rotating shaft) of the vibration. Since it is located, almost no stress due to vibration occurs. The piezoelectric body is formed with a certain width, but since it is formed in line symmetry with respect to the X axis (support axis), it has
Since the generated voltages are canceled in the Y direction and the -Y direction), no output can be obtained.

(3) When receiving vibration in the Z direction The relationship between this vibration and stress is the same as in 1- (1) above. Therefore, between the sensing electrode and the common electrode, that is, X
Between 11 and X12 and between X23 and X22, a potential difference with the same polarity and absolute value is generated, and the same relationship holds between X13 and X12 and between X21 and X22. Therefore, the wiring of the X-axis detector has no sensitivity as described below. Vx = V (11-12) -V (13-12) + V (21-22) -V (23-22) where V (11-12) = V (23-22), V (13-12) ) = V (21-22) Therefore, Vx = 0

3. Action of Y-Axis Detection Unit This can be considered in the same manner as the action of the X-axis detection unit.

A method of manufacturing such a piezoelectric vibration sensor will be described. In advance, an electric circuit is formed on one surface of the diaphragm diaphragm 2 and the detection electrode 12 connected to this electric circuit is formed in advance. Then
The diaphragm vibrating plate 2 is attached to the support 4, the piezoelectric body 10 is attached to the diaphragm vibrating plate 2, the common electrode 11 is provided on the piezoelectric body, and the piezoelectric vibration sensor 1 is assembled.

(Modification 1) Further, in the piezoelectric vibration sensor of the present invention, as shown in FIG. 6, the load body 20 may be fixed to the diaphragm diaphragm 2 in order to improve the sensitivity. When the load body 20 is fixed to the center of the diaphragm diaphragm 2,
By providing each of the detection units 5, 6, and 7 near the fixed end of the load body 20 located at the center of the diaphragm diaphragm 2, higher stress is generated and sensitivity can be increased. That is, in the case of the diaphragm type, it is the outer peripheral portion and the central portion of the diaphragm diaphragm 2 that generate high stress due to the vibration, and when the load body 20 is fixed to the central portion of the diaphragm diaphragm 2, It is desirable to fix the detectors 5, 6, and 7 so that the fixed end shows a high stress concentration and the fixed end is applied to this region.

[0027]

EXAMPLES Examples of the piezoelectric vibration sensor of the present invention will be described below with reference to a test example of a triaxial detection type piezoelectric vibration sensor. (Test Example 1) The diaphragm diaphragm is made of alumina having a detection electrode and an electric circuit, and is 30 mm x 30 m.
It is formed in a size of m × 1.0 mm ^t . A glass fiber reinforced epoxy resin is used as a support for supporting the diaphragm diaphragm, and the outer shape thereof is 30 mm × 30 mm × 5 mm.
It is formed to a size of ^t , and a 10 mmφ hole is formed in the center thereof. The piezoelectric body is polyvinylidene fluoride (PVDF)
It used, (the length varies by the detection axes) which 2mm ^w × 110μm ^t formed to the size of the. The electrode pattern is formed similarly to FIG. That is, a detection electrode and an electric circuit are formed in advance on the diaphragm diaphragm, and then a piezoelectric body and a common electrode are provided.

(Test Example 2) The diaphragm diaphragm was made of alumina on which a detection electrode and an electric circuit were formed.
It is formed in a size of mm × 30 mm × 0.4 mm ^t . The support that supports the diaphragm diaphragm is made of glass fiber reinforced epoxy resin and has an outer shape of 30 mm x 30 mm.
× 5mm ^t in size, 10mmφ in the center
To form holes. The piezoelectric body uses PZT, which is 2 m
m ^w × 450 μm ^t (length varies depending on the detection axis). The electrode pattern is formed similarly to FIG.

(Test Example 3) The diaphragm diaphragm was made of alumina on which a detection electrode and an electric circuit were formed.
It is formed into a size of mm × 30 mm × 0.5 mm ^t . The support that supports the diaphragm diaphragm is made of glass fiber reinforced epoxy resin and has an outer shape of 30 mm x 30 mm.
× 10mm ^t size, 10mm in the center
Form a φ hole. Furthermore, as shown in FIG. 6, a load body is fixed to the central portion of this diaphragm diaphragm. This load body is made of brass and has an outer shape of approximately 8 mmφ × 8 mm ^t . The portion of the load body fixed to the diaphragm diaphragm is formed to have a size of 3 mmφ × 1 mm ^t . The piezoelectric material is polyvinylidene fluoride (PVD
F) is used, and this is formed into a size of 2 mm ^w × 110 μm ^t (the length varies depending on the detection axis). The electrode pattern is formed similarly to FIG.

(Test Example 4) The diaphragm diaphragm uses alumina on which a detection electrode and an electric circuit are formed.
It is formed into a size of mm × 30 mm × 0.5 mm ^t . A glass fiber reinforced epoxy resin is used as a support for supporting the diaphragm diaphragm, and the outer shape thereof is 30 mm × 30 mm × 10.
mm ^t , and a 10 mmφ hole is formed in the center thereof. Further, the load body is fixed to the central portion of the diaphragm diaphragm. This load body is made of brass and is formed to have an outer shape of approximately 8 mmφ × 8 mm ^t . The portion of this load body that is fixed to the diaphragm diaphragm is 3 mmφ ×
Form to 1 mm ^t . The piezoelectric body is PZT, 2 mm ^w
× 450 μm ^t (length varies depending on the detection axis). The electrode pattern is formed similarly to FIG.

(Comparative Example 1) The diaphragm diaphragm is made of alumina and is formed to have a size of 15 mmφ × 1.0 mm ^t . The support that supports the diaphragm diaphragm is made of glass fiber reinforced epoxy resin, which is 15 mmφ × 5 mm.
^It is formed at ^t and a hole of 10 mmφ is formed at the center. For the piezoelectric body, polyvinylidene fluoride (PVDF) is used, and it has the same size as the diaphragm diaphragm and a thickness of 110 μm.
To form. As shown in FIG. 7, the electrode pattern is configured such that the detection electrodes 31, ... Are provided on the upper surface of the piezoelectric body 32 and the common electrode 33 is provided on the lower surface of the piezoelectric body 32. This piezoelectric body 3
2 has the same size as the diaphragm diaphragm 2 and a thickness of 11
It is formed to 0 μm and attached to the diaphragm diaphragm 2.

(Comparative Example 2) The diaphragm diaphragm is made of alumina and is formed to have a size of 15 mmφ × 0.4 mm ^t . The support that supports the diaphragm diaphragm uses glass fiber reinforced epoxy resin, which is 15 mmφ (outer circumference).
× 5 mm ^t , and a 10 mmφ hole is formed in the center. As the piezoelectric body, PZT is used, and this is formed to have a size similar to that of the diaphragm diaphragm and a thickness of 450 μm ^t . The electrode pattern is the same as in FIG. 7.

(Comparative Example 3) A diaphragm is made of alumina and is formed to have a size of 15 mmφ × 0.5 mm ^t . A glass fiber reinforced epoxy resin is used as a support for supporting the diaphragm diaphragm, which is 15 mmφ × 10 m.
m ^t , and a 10 mmφ hole is formed in the center.
Further, the load body is fixed to the lower surface of the central portion of the diaphragm diaphragm. The load body, using a brass, which forms the outer shape substantially 8 mm × 8 mm ^t. The part where this load is fixed to the diaphragm is 3mmφ x 1mm ^t.
To form. As the piezoelectric body, PZT is used, and this is formed to have a size similar to that of the diaphragm diaphragm and a thickness of 450 μm ^t . The electrode pattern is the same as in FIG. 7.

(Comparative Example 4) The diaphragm diaphragm is made of alumina and is formed to have a size of 15 mmφ × 0.5 mm ^t . A glass fiber reinforced epoxy resin is used for the support that supports the diaphragm diaphragm, and the outer shape is 15 mmφ ×
It is formed to 10 mm ^t, and a hole of 10 mmφ is formed in the center thereof. Furthermore, at the center of this diaphragm diaphragm,
Fix the load body. The load body, using a brass, which forms the outer shape substantially 8 mm × 8 mm ^t. The part where this load is fixed to the diaphragm diaphragm is 3mmφ x 1m
It is formed on the m ^t. As the piezoelectric body, PZT is used, and this is formed to have a size similar to that of the diaphragm diaphragm and a thickness of 450 μm ^t . The electrode pattern is the same as in FIG. 7.

With respect to each of the above-mentioned examples, a sensor was prototyped and its performance was evaluated. Moreover, the manufacturing cost in each example was compared. The results are shown in Table 1.

[Table 1]

In Table 1, the performance is standardized by the Z-axis sensitivity of Example 1, and the cost is standardized by Example 1. From Table 1, it is possible to provide a sensor with low material cost by arranging the detection unit having the strip-shaped piezoelectric body on the diaphragm diaphragm. Further, since the pattern of the detection electrodes can be directly formed on the diaphragm and the signal processing circuit can be formed on the same substrate, it is possible to provide a sensor with low manufacturing cost.

[0037]

As described above, according to the piezoelectric type vibration sensor of the present invention, the diaphragm diaphragm and the detection unit arranged on one surface of the diaphragm diaphragm for detecting the vibration of the diaphragm diaphragm. In the piezoelectric vibration sensor having, the detection unit is arranged on the x-axis with the intersection point sandwiched, when the axes orthogonal to the intersection point of the center of one surface of the diaphragm are the x-axis and the y-axis. A pair of strip-shaped x-axis detection units, a pair of strip-shaped y-axis detection units arranged on the y-axis across the intersection, and a pair of strip-shaped z arranged at point-symmetrical positions across the intersection. It has an axis detector and these x
The axis, the y-axis, and the z-axis detection unit include a strip-shaped piezoelectric body and a common electrode that is arranged on almost one entire surface of the piezoelectric body.
The other surface of the piezoelectric body has a pair of detection electrodes arranged along the longitudinal direction of the piezoelectric body, and vibrates from a charge amount or a potential difference generated between each of the detection electrodes and the common electrode. Is detected, the vibration of each axis can be detected by the belt-shaped piezoelectric body. Therefore, the amount of expensive piezoelectric material used can be reduced, and the material cost of the piezoelectric vibration sensor can be reduced.

According to the manufacturing method of the present invention, the sensing electrode and the electric circuit connected to the sensing electrode are provided on one surface of the diaphragm diaphragm in advance, and then the diaphragm diaphragm and the piezoelectric body are assembled. It is not necessary to take out the electrode from the piezoelectric body with a lead wire or the like, and the manufacturing work process of the piezoelectric vibration sensor can be reduced. Further, since the detection electrode is formed on the diaphragm diaphragm, it is not necessary to directly form an electrode on the piezoelectric body having poor heat resistance, and the electrodes can be arranged on both surfaces of the piezoelectric body. Therefore, various piezoelectric materials can be used, and the piezoelectric vibration sensor having various performances can be manufactured.

[Brief description of drawings]

FIG. 1 is a perspective view showing a piezoelectric vibration sensor of the present invention.

FIG. 2 is a cross-sectional view showing the piezoelectric vibration sensor of FIG.

FIG. 3 is an enlarged sectional view of FIG.

4 is a configuration diagram showing a signal processing circuit of the X-axis detection unit of FIG. 1. FIG.

5 is a configuration diagram showing a signal processing circuit of the Z-axis detection unit of FIG. 1. FIG.

FIG. 6 is a cross-sectional view showing a modified example of FIG.

FIG. 7 is a cross-sectional view showing a comparative example.

[Explanation of symbols]

1 ... Piezoelectric vibration sensor, 2 ... Diaphragm diaphragm, 3 ...
Detection unit, 4 ... Support, 10 ... Piezoelectric body, 11 ... Common electrode,
12 ... Detection electrode.

Claims (3)

[Claims] 1. A piezoelectric vibration sensor having a diaphragm diaphragm and a detector arranged on one surface of the diaphragm diaphragm for detecting the vibration of the diaphragm diaphragm, wherein the detector is a diaphragm of the diaphragm. When the axes orthogonal to each other with the center of one surface as an intersection point are defined as x axis and y axis, a pair of strip-shaped x's arranged on the x axis across the intersection point.
An axis detection unit, a pair of band-shaped y-axis detection units arranged on the y-axis across the intersection, and a pair of band-shaped z-axis detection units arranged at point-symmetrical positions across the intersection. Have these x
The axis, the y-axis, and the z-axis detection unit include a strip-shaped piezoelectric body and a common electrode that is arranged on almost one entire surface of the piezoelectric body.
The other surface of the piezoelectric body has a pair of detection electrodes arranged along the longitudinal direction of the piezoelectric body, and vibrates from a charge amount or a potential difference generated between each of the detection electrodes and the common electrode. A piezoelectric vibration sensor, which is characterized by detecting 2. The piezoelectric vibration sensor according to claim 1, wherein the sensing electrode and an electric circuit connected to the sensing electrode are formed on one surface of the diaphragm diaphragm. 3. The method for manufacturing a piezoelectric vibration sensor according to claim 2, wherein the sensing electrode and the electric circuit are provided on one surface of the diaphragm diaphragm in advance, and then the piezoelectric body A method for manufacturing a piezoelectric vibration sensor, characterized in that electrodes are provided.