JP2002262383A - Ultrasonic wave vibrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized ultrasonic wave vibrator with a high output manufactured at a reduced manufacturing cost that has an anisotropic directivity. SOLUTION: A diaphragm 2 of the ultrasonic wave vibrator is made of a metal and configured with a vibration section 4 and a vibration support section 5. One side of the vibration section 4 is formed to be an ultrasonic wave transceiving face 4a and the vibration support section 5 is extended toward a placing face 4b from two sides opposed to each other of an outer edge of the vibration section 4. Furthermore, since the vibration support section 5 is structured to be connected to a metal-made support member 6 placed therearound, the vibration in the vicinity of a side face 1c is suppressed to concentrate the vibration onto the vibration section 4 on which a piezoelectric element 7 is placed, with the result that an output sound pressure can be increased. After the end of oscillation of ultrasonic waves, since the mechanical vibration energy left in the side face 1c is decreased, the reverberation is reduced and the reception accuracy of a reflected wave is enhanced to improve the response performance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates detects the presence of an obstacle by receiving reflected waves from an obstacle while oscillating ultrasonic waves, the ultrasonic vibration can be applied to an ultrasonic sensor used as a vehicle-mounted like It is about the child.

[0002]

2. Description of the Related Art As a conventional ultrasonic sensor for detecting an obstacle mounted on a vehicle, an ultrasonic wave is oscillated in the air from the ultrasonic sensor and is reflected by an obstacle such as an object to be detected. Received by the ultrasonic sensor, processed the received signal,
Some are configured to issue an alarm or the like.

FIG. 2 shows the state of attachment of such an ultrasonic sensor.
It is shown in FIG. The ultrasonic sensor 13 is mounted on a bumper 15 of an automobile 14. Here, in order to detect an obstacle existing around the bumper 15 that hinders the movement of the automobile 14 and not to detect an obstacle such as a road surface that does not hinder the movement of the automobile 14, Therefore, it is necessary to use the ultrasonic sensor 13 having a detection area that is wide in the horizontal direction and narrow in the vertical direction.

[0004] Such an ultrasonic transducer for the ultrasonic sensor 13 having an omnidirectional directivity characteristic that is wide in the horizontal direction and narrow in the vertical direction with respect to the road surface has already been filed by the applicant of the present invention. (Japanese Patent Application Laid-Open No. 2001-78296). The main part of the configuration of this ultrasonic transducer is 22 (a),
It is shown in (b). (a) is a sectional view, and (b) is a sectional view during operation. The ultrasonic vibrator has a closed surface 16a of a case body 16 having an open end and a closed surface 16a at the other end.
The piezoelectric element 7 is disposed on the inner surface side of the case, and has a directional characteristic of the different direction of the ultrasonic wave generated at the closing surface 16a, and the case body 16 is formed of a closing surface 16a formed of a metal plate. And a resin case 18 made of a synthetic resin material. In manufacturing the ultrasonic vibrator, a metal plate for the metal case 17 does not require a forging step or a cutting step, so that the metal case 17 can be formed easily at low cost. .

[0005]

[SUMMARY OF THE INVENTION However, since the above-mentioned ultrasonic vibrator which is part of the metal case 17 is constituted by a plate member, as shown in FIG. 22 (b), the inner peripheral surface of the inner casing 16 The strength of the side portion 16b, which is a region perpendicular to the closed surface 16a, is low, and the side portion 16b
Vibrates in accordance with the vibration of the closing surface 16a provided with. Therefore, mechanical vibration energy is dispersed from the closed surface 16a to the side surface portion 16b, and the vibration energy of the closed surface 16a is smaller than when only the closed surface 16a vibrates.

Further, as conceptually shown in FIG. 22A, the circuit to which the piezoelectric element 7 is connected has a load resistor 19, and the closed surface 16 due to the vibration of the piezoelectric element 7 is provided.
Most of the mechanical residual energy remaining in the case body 16 after the completion of the oscillation of the ultrasonic wave from the piezoelectric element 7 is converted into electrical energy by the piezoelectric element 7 disposed on the closed surface 16a.
Although the heat is consumed as heat by the load resistor 19, when the mechanical vibration energy is dispersed in a portion other than the closed surface 16a in which the piezoelectric element 7 is disposed, the mechanical residual energy is consumed after the end of the ultrasonic oscillation. However, the reverberation becomes longer, the receiving accuracy of the reflected wave deteriorates, and the responsiveness of the ultrasonic transducer deteriorates.

Further, when the ultrasonic vibrator is mounted on the bumper 15 of the automobile 14, the side face 16b is easily displaced by the stress applied to the ultrasonic vibrator by the mounting jig. As a result, the ultrasonic vibrator is displaced. There was a possibility that the vibration characteristics of the device would change.

In order to improve the above point, for example, in the prior application (Japanese Patent Application No. 2000-300884) of the present applicant, as shown in FIGS. Has been proposed to insert and bond the inside of the vibrator, but there are problems such as an increase in the number of parts, the bonding process, etc., resulting in an increase in variation in performance and an increase in the manufacturing cost of the ultrasonic vibrator. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has a small size, a high output, and a low manufacturing cost while ensuring stable vibration characteristics of an ultrasonic vibrator having an omnidirectional directional characteristic. It is an object of the present invention to provide an ultrasonic vibrator in which reduction is achieved.

[0010]

In order to solve the above-mentioned problems, an ultrasonic vibrator according to the first aspect of the present invention has a substantially uniform edge having two edges which are linearly symmetric with each other. A vibrating portion made of a metal plate having a thickness, and including a center of gravity of the vibrating portion, and having a plane-symmetric relationship with respect to a plane orthogonal to the vibrating portion and the two edges, and A vibration support portion extending in the same direction from two sides opposed to each other, and an ultrasonic transducer including at least a piezoelectric element disposed on a surface of the vibration portion on the side having the vibration support portion, The vibration support portion has a structure connected to a support member provided around the vibration support portion.

In the ultrasonic vibrator according to the second aspect of the present invention, a vibrating portion made of a metal plate having a substantially uniform thickness and having two edges that are in a line-symmetrical relationship with each other is provided. A support including a center of gravity and having a plane-symmetric relationship with respect to a plane orthogonal to the vibrating portion and the two edges, and extending in the same direction from two opposing sides of the outer edge of the vibrating portion. In an ultrasonic vibrator including at least a member and a piezoelectric element disposed on a surface of the vibrating portion on a side having the support member, the supporting member has two sides of an outer edge of the vibrating portion facing each other. , Characterized by having an annular structure bridged by the vibrating part.

According to a third aspect of the present invention, in the ultrasonic transducer according to the first aspect, the vibration supporting portion is joined to the annular support member surrounding the vibration supporting portion. It is a feature.

According to a fourth aspect of the present invention, in the ultrasonic vibrator according to the first aspect, the vibration support portion is formed integrally with the annular support member. Is what you do.

According to a fifth aspect of the present invention, there is provided an ultrasonic vibrator according to any one of the first to third aspects, wherein the supporting member is a metal plate constituting the vibrating portion. It is characterized in that it is made of a metal material having a greater longitudinal elastic modulus.

According to a sixth aspect of the present invention, in the ultrasonic vibrator according to the fifth aspect, the support member is made of a metal material containing iron as a main component, and the vibrating portion is formed. It is characterized by being composed of a metal material containing aluminum as a main component (here, a metal material containing iron as a main component refers to a metal material containing 50% by weight or more of iron and mainly containing aluminum. The term “metal material as a component” means a metal material containing 50% by weight or more of aluminum.)

According to a seventh aspect of the present invention, in the ultrasonic vibrator according to any one of the first to sixth aspects, the support member is parallel to the two opposite sides. It has an external plane orthogonal to the vibrating section.

In the ultrasonic vibrator according to an eighth aspect of the present invention, in the ultrasonic vibrator according to the seventh aspect, the portion of the support member having the external plane is larger than other portions of the support member. It is characterized in that it is made thick.

According to a ninth aspect of the present invention, in the ultrasonic transducer according to any one of the first to eighth aspects, the support member has an upper open edge,
The upper open edge is formed at substantially the same height as the diaphragm.

According to a tenth aspect of the present invention, in the ultrasonic vibrator according to any one of the first to ninth aspects, the support member comprises at least one kind of liquid crystal polymer. It is characterized in that it is completely covered with a resin molding material.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. The ultrasonic vibrator of the present invention is not limited to the embodiment described below, and it goes without saying that various changes can be made without departing from the scope of the present invention.

The basic structure of the ultrasonic transducer according to the present embodiment will be described with reference to FIGS. FIG. 1 shows a main part of an ultrasonic vibrator according to claim 1, wherein (a) is a cross-sectional view cut in a direction without a vibration support portion, and (b) is a cross-sectional view cut in a direction having a vibration support portion. It is sectional drawing. FIG. 2 shows a part of a manufacturing process of the ultrasonic vibrator according to the present invention, and is a view sequentially showing connection and molding of a diaphragm and a support member.
3A and 3B show a part of the manufacturing process of the ultrasonic vibrator according to the present invention, wherein FIG. 3A is a diagram showing an example of connection between a diaphragm and a support member, and FIG. It is a figure which shows the example of a connection with the support member of a different shape. The case body 1 includes a metal diaphragm 2 and a synthetic resin resin case 3 as shown in FIG.
It is comprised including. The vibration plate 2 is made of a metal material containing aluminum as a main component, and includes a vibration portion 4 and a vibration support portion 5. The vibrating portion 4 is made of a metal plate having a substantially uniform thickness and having two edges 4c in a line-symmetrical relationship with each other. Here, the vibrating portion 4 is formed in a rectangular plate shape having a substantially uniform thickness. Is the ultrasonic transmitting / receiving surface 4a
The other surface is formed as an arrangement surface 4b on which the piezoelectric element 7 is arranged. The vibration support portion 5 includes a center of gravity of the vibration portion 4 and has a plane-symmetric relationship with respect to a plane orthogonal to the vibration portion 4 and the two edges 4c. It extends in the same direction from two opposing sides, and here extends from two opposing sides of the outer edge of the vibrating part 4 toward the arrangement surface 4b. On the other hand, the remaining two sides are formed as the non-connection portions 4c that are not directly connected to the vibration support portion 5, that is, the two edges. Another pair of opposing sides is a connecting portion 4 where the vibrating portion 4 and the vibration supporting portion 5 are connected.
d. That is, in the present embodiment, the non-connecting portions 4c and the connecting portions 4d alternately formed along the outer edge of the vibrating portion 4 have the arrangement direction of the non-connecting portions 4c and the arrangement direction of the connecting portions 4d. They are arranged so as to be substantially orthogonal.

As shown in FIG. 2, the annular supporting member 6 is integrated so as to sandwich the vibration supporting portion 5 of the diaphragm 2 from both sides to form an insert member 23, which is formed into a composite material having excellent vibration damping properties. It is molded simultaneously with the cylindrical resin case 3 made of resin. Further, when arranging the piezoelectric element 7 later, at the time of molding of the resin case 3 so as not to cause inconvenience, disposition surface 4b of the oscillating portion 4
It is necessary to take care that the molding material resin does not flow around. The vibrating part 4 of the vibrating plate 2 is formed so as to close the opening on the front side of the resin case 3 and the ultrasonic transmitting / receiving surface 4 a of the vibrating part 4 is substantially flush with the front surface of the resin case 3. constitute a blocking surface 1b. The support member 6 is made of a metal material and has an annular shape. However, even if the support member 6 has a substantially elliptical shape as indicated by reference numeral 6 in FIG.
In (b), it may be a polygonal one as indicated by reference numeral 6a, and there is no limitation as long as it contributes to solving the above-mentioned problem.

A pair of non-connecting portions 4c of the vibrating portion 4 of the ultrasonic vibrator are fixed by the resin case 3 so as to be easily bent, while a pair of connecting portions 4d are formed of the metal vibration supporting portion 5 and the And is fixed by a supporting member 6 connected to the supporting member 6. The piezoelectric element 7 is fixed and disposed on an arrangement surface 4b of the vibration section 4 with an adhesive. A lead wire 8 is connected to the vibration supporting portion 5 of the metal case 2, and a lead wire 9 is connected to a surface of the metal case 2 which is not connected to the arrangement surface 4 b of the piezoelectric element 7.

A sound absorbing material 10 made of felt or the like is disposed inside the resin case 3. The sound absorbing material 10 is provided on the opposite side of the vibrating portion 4 of the piezoelectric element 7 from the piezoelectric element 7. 7 are arranged slightly apart from each other.

As shown in FIG. 1, the resin case 3 is filled with a filler 11 made of resin from the surface of the sound absorbing material 10 to the open end 1a. Are sealed with resin. As the filler 11 made of this resin, a resin that cures over time can be used, and for example, a silicone resin can be used.

The ultrasonic vibrator thus constructed is configured by applying a pulse voltage between the lead wires 8 and 9 and connecting a control circuit for measuring a voltage generated between the lead wires 8 and 9. , Can be configured as an ultrasonic sensor. Then, when a pulse voltage is applied between the lead wires 8 and 9, the piezoelectric element 7 vibrates, and the vibrating part 4 vibrates accordingly to oscillate ultrasonic waves. When the ultrasonic wave oscillated from the vibrating section 4 hits an obstacle or the like and is reflected, and the reflected wave hits the ultrasonic transmitting / receiving surface 4a of the vibrating section 4, the vibrating section 4 vibrates, and the piezoelectric element 7 vibrates accordingly. I do. At this time, an electromotive force is generated in the piezoelectric element 7, and the lead wires 8,
The presence or absence of an obstacle can be detected by detecting the electromotive force between the nine.

FIG. 4 is a view showing an example of a use form of the ultrasonic vibrator according to the present invention. That is, when such an ultrasonic vibrator is mounted on a mounting object such as a bumper of an automobile, the vibrator is housed in the ultrasonic sensor housing, and the closed surface of the case body 1 is formed in the opening 12 formed in the mounting object. 1
b is disposed so as to be exposed to the outside. At this time, particularly when the ultrasonic vibrator is mounted on a vehicle bumper or the like for use in a vehicle, the closed surface 1b of the case body 1 is disposed substantially perpendicular to the horizontal plane, and a pair of non-connection portions 4c are arranged in the horizontal direction, and a pair of connecting portions 4d are arranged in the vertical direction.

When oscillating an ultrasonic wave from an ultrasonic transducer,
The vibration mode in the horizontal direction (the direction from one connecting portion 4d to the other connecting portion 4d) in the vibrating portion 4 is a simple bending vibration, but is vertical bending (from one non-connecting portion 4c to the other non-connecting portion). In the vibration mode (direction toward 4c), the non-connection portion 4c is fixed to the resin case 3 and is supported by the resin, so that the vibration is easy to bend. Therefore, the plane vibration is larger than the horizontal vibration mode. That is, even if the vibrating portion 4 is formed in a flat plate shape having a substantially uniform thickness, the vibrating portion 4 can generate a substantially saddle-shaped vibration mode. As a result, the direction of oscillation of the ultrasonic waves generated by the vibration of the vibrating part 4 is sharper than the horizontal direction and does not spread in the vertical direction. Spreading is provided, but directivity having an anomalous direction in which spreading in the vertical direction is narrowed is provided. Accordingly, the detection area of the ultrasonic transducer is wide in the horizontal direction and narrow in the vertical direction, and the transmission output of the ultrasonic wave is improved. Therefore, when such an ultrasonic vibrator is used, for example, for use in a vehicle, it is possible to prevent detection of an object that does not hinder the movement of the vehicle such as a road surface.

Also, since the ultrasonic waves oscillated from the ultrasonic vibrator have directivity having different directions, the directivity is imparted to the ultrasonic waves in the forward direction, which is the oscillation direction of the ultrasonic waves from the ultrasonic vibrator. It is not necessary to provide a horn or the like, and the ultrasonic vibrator can be directly exposed to the outside without forming a depression or the like in front of the ultrasonic vibrator, and rainwater, Prevents foreign substances such as snow and dust from accumulating. Such foreign substances may change the detection area where ultrasonic transducers can detect obstacles. This can prevent malfunction such as notifying.

Further, when the ultrasonic vibrator is attached to the object to be mounted, the closed surface 1b of the case body 1 can be disposed so as to be flush with the surface of the object to be mounted. It is possible to improve the appearance in the mounted state without protruding from the surface of the object or exposing the opening to the outside.

In the ultrasonic vibrator thus constructed, the waterproof end of the ultrasonic vibrator is improved by closing the opening end 1a of the case body 1 with the filler 11.
An ultrasonic sensor of drip-proof specification can be obtained. When the piezoelectric element 7 is vibrated to oscillate ultrasonic waves, a region near the inner peripheral surface of the support member 6 of the vibration support portion 5 shown in FIG. Closed surface 1 on which piezoelectric element 7 is disposed by being fixed to rigidity
Vibration energy concentrates on b, and the output sound pressure increases. After the vibration of the piezoelectric element 7 is stopped and the driving of the ultrasonic vibrator is completed, the mechanical vibration energy remaining in the ultrasonic vibrator is converted into electric energy by the piezoelectric element 7 and connected to the piezoelectric element 7. When it is consumed as heat by the load resistor 19 (not shown) of the circuit,
When the vibration of the case body 1 is concentrated on the closing surface 1b on which the piezoelectric element 7 is disposed, the mechanical vibration energy is efficiently converted into electric energy by the piezoelectric element 7 and further consumed by the load resistance. . As a result, in which the vibration of the ultrasonic vibrator reverberation is shortened becomes to be quickly attenuated, and improves reception accuracy of the reflected wave is improved responsiveness of the ultrasonic transducers.

Further, the rigidity of the side surface portion 1c is ensured by the annular support member 6, so that it is not necessary to pack the rigid member in the case body 1 and bond it as in the conventional case, and the structure can be simplified. Therefore, the manufacturing cost can be reduced. The support member 6 in order to be able to a metal material of high rigidity, can be thinner in thickness to ensure a predetermined rigidity can be configured reduce the height of the case body 1.

FIGS. 5 and 6 show variations of the diaphragm 2 and the support member 6 and the connection between them. That is, FIG.
As shown in FIG. 3, the case body 1 is integrated with the annular support member 6 so as to sandwich the vibration support portion 5 of the diaphragm 2 from both sides to form an insert member 23, which is formed into a cylindrical shape of synthetic resin. Can be formed simultaneously with the resin case 3, but the form of connection between the diaphragm 2 and the support member 6 is not limited to this. 5A is a cross-sectional view when the diaphragm 2 is joined at the bottom surface of the support member 6, FIG.
(b) is a cross-sectional view when the diaphragm 2 is joined and joined at the bottom and side surfaces of the support member 6, and (c) is a cross-sectional view when the diaphragm 2 a is joined at the top surface of the support member 6. In the drawings, the joining portions are portions 20, 21, and 22 indicated by broken lines. That is, the vibration in the vicinity of the side surface portion 1c is suppressed regardless of whether the joining portion is any one of the above 20, 21 and 22, so that the vibration is generated in the piezoelectric element 7.
Is concentrated on the vibrating section 4 disposed as described above, and as a result, the output sound pressure can be improved. FIG. 6 shows a part of a manufacturing process different from that shown in FIGS. 2 and 3 of the ultrasonic transducer according to the present invention.
This corresponds to the form of connection between the diaphragm 2a and the support member 6 in (c). Also in this case, as in the case shown in FIG. 2, the insert member 23 is formed, and this is formed simultaneously with the cylindrical resin case 3 made of synthetic resin to form the case body 1. In any of the above cases, regarding the material configuration, for example, when the diaphragm 2 is made of a metal material containing aluminum as a main component (aluminum-based metal material), the support member 6 is the same material as the diaphragm 2. Even a metal material containing aluminum as a main component has a higher longitudinal elastic modulus than a metal material containing aluminum as a main component, and is a highly rigid metal material containing iron as a main component (iron-based metal material), such as stainless steel and SPCC. Of different materials. Regarding the joining method, when both the diaphragm 2 and the support member 6 are made of a metal material mainly composed of aluminum, ultrasonic welding is performed.
It is joined by resistance welding or the like, and in the case of another material as described above, it is joined by a method which can join different metals such as aluminum solder, laser welding, caulking, adhesion and the like. As shown in FIG. 5, the joining portion can be any of the bottom surface, the side surface, and the top surface of the support member 6, and can be joined by an optimal joining method according to each joining portion.

When the diaphragm 2 is made of a metal material containing aluminum as a main component, the diaphragm 2 can be suitably formed by punching and bending a plate material. In this case, the resonance frequency, which is an important vibration characteristic of the ultrasonic vibrator, depends on the thickness of the vibrating portion 4 of the vibrating plate 2, and the thickness of the vibrating portion 4 is controlled by the thickness of the base material. Thereby, the error between individual resonance frequencies can be reduced. When both the diaphragm 2 and the support member 6 are formed of a metal material containing aluminum as a main component, the joining time between the support member 6 and the diaphragm 2 is short, such as ultrasonic welding and resistance welding, and the joining state is stable. It is possible to stably manufacture at low cost.

On the other hand, when the supporting member 6 is formed of a metal material containing iron as a main component, such as a stainless steel material or an SPCC material, which is a different material from the diaphragm 2, the supporting member 6 has a large longitudinal modulus of elasticity. Even if the thickness of the member 6 is reduced, its rigidity can be sufficiently ensured, and the height of the resin case 3 in the direction perpendicular to the vibrating portion 4 can be reduced. As a result, the height of the ultrasonic vibrator can be kept low, the ultrasonic sensor can be downsized, and the depth can be kept low.
A dimensional allowance for the depth can be ensured.

Hereinafter, an embodiment of the invention according to claim 2 will be described. FIGS. 7 to 9, 11, 12, and 14 to 16 show an ultrasonic transducer which can be formed in the same manner as the ultrasonic transducer shown in FIG. That is, the one shown in FIGS. 7 and 8 has a structure in which the vibration supporting portion 5 of the insert member 23 is completely integrated with the supporting member 6 as compared with the one shown in FIG. Since the plate 2 has a structure connected to the supporting member 6 provided around the plate 2, the vibration concentrates on the diaphragm 2 on which the piezoelectric element 7 is disposed, and as a result, the output sound pressure can be improved. After the oscillation of the ultrasonic wave is completed, the reverberation is shortened, the receiving accuracy of the reflected wave is improved, and the response performance can be improved. In addition, the support member 6 shown in FIG. 7 can be manufactured from a pre-made cylindrical pipe, and the support member 6 shown in FIG. 8 can be manufactured by bending a plate, so that mass production is easy. It can also contribute to rationalization requests.

9 is similar to the above in that the output sound pressure and the response performance can be improved, but the annular support member 6 has a linear outer peripheral portion 24a as shown in FIG. After the formation of the insert member 23, the annular support member 6 forms an outer flat surface 25a that is parallel to the connecting portion 4d, which is the two opposing sides of the diaphragm 2, and that is orthogonal to the vibrating portion 4. Therefore, the corresponding case body 1 after molding can be formed into a molded body having the same outer shape plane 26a, and the direction of the ultrasonic sensor can be determined by using the outer shape plane 26a of the case body 1 as a clue. Can be mounted correctly, and the directional characteristics of the ultrasonic sensor can be reliably exhibited.

On the other hand, the one shown in FIG. 11 is also similar to that shown in FIG.
Although having the point 5b is the same as that shown in FIG. 9, it can be said that the point having the independent vibration support part 5 is rather the same as that shown in FIG. In addition to the improvement of the output sound pressure and the response performance, the point that the direction of the ultrasonic sensor can be correctly mounted by using the outer flat surface 26b of the case body 1 as a clue is the same as that shown in FIG.

The one shown in FIG.
Form after formation of 3, it is similar to that shown in FIG. 9,
As shown in FIG. 13, the annular support member 6 is
In addition to having a cross-sectional shape with c, the portion having the straight outer peripheral portion 24c, that is, the portion having the outer flat surface 25c of the annular support member 6 is thicker than other portions of the annular support member 6. It is configured. As a result, the rigidity of the annular support member 6 can be further increased, and the effect unique to the present invention of improving the output sound pressure and the response performance is further enhanced as compared with the one shown in FIG.

FIGS. 14 to 16 show an embodiment in which the upper open edge 27 of the annular support member 6 after the formation of the insert member 23 is formed at substantially the same height as the diaphragm 2.

FIG. 17 is a sectional view of the case body 1 formed by simultaneously molding the insert member 23 having such a structure with the resin case 3, and FIG. FIG. 18 is a cross-sectional view corresponding to FIG. When the upper end of the annular support member 6 is formed with a uniform height, the resin portion 28 facing the edge 4c of the diaphragm 2 in FIG. 18A is replaced with the corresponding resin portion 28 in FIG. Larger than. As a result, in the ultrasonic sensor shown in FIG. 18, the temperature dependence of the directivity characteristics by vibration mode change of the ultrasonic sensor, large temperature dependency, such as resonance frequency, a stable problem that it is difficult to secure the sensor characteristics Will have. That is, the resin material has a large temperature dependency of the elastic modulus as compared with the metal material, and the ultrasonic sensor shown in FIG. 18 in which the resin portion 28 is large has a relatively large temperature dependency such as a directional characteristic and a resonance frequency. Because it is big. Conversely, the upper open edge 2 of the annular support member 6 after the formation of the insert member 23
By making the height 7 substantially the same as the height of the diaphragm 2, in the ultrasonic sensor shown in FIG. 17 in which the resin portion 28 is made smaller, it is possible to reduce the temperature dependency such as the directional characteristics and the resonance frequency, and to secure stable sensor characteristics. Can be done.

Among the ultrasonic transducers according to the present invention which have improved sensor characteristics, the one shown in FIG. 14 can improve the performance and also can manufacture the support member 6 with a pre-made cylindrical pipe. It is easy to mass-produce and can contribute to rationalization requests.

Further, the one shown in FIG.
However, since it is configured with a uniform thickness and can be manufactured by bending a plate material having a uniform thickness, mass production is easy and it can contribute to a request for rationalization. Since the corresponding case body 1 after molding has a contoured body 26 having the same outer contour plane 26 as having the outer contour plane 25 which is parallel to the connection part 4d which is two opposite sides and is orthogonal to the vibrating part 4, The direction of the ultrasonic sensor can be correctly attached using the outer surface 26 as a clue, so that the directional characteristics of the ultrasonic sensor can be surely exhibited.

FIG. 16 shows an insert member 2
The form after formation of 3 is similar to that shown in FIG. 15, but the portion of the annular support member 6 having the outer flat surface 25 is configured to be thicker than other portions of the annular support member 6.
As a result, the rigidity of the annular support member 6 can be further increased, and the effect unique to the present invention of improving the output sound pressure and the response performance is further enhanced as compared with the one shown in FIG. Further, in this case, it is possible to manufacture the annular support member 6 by forging, which also has an advantage that mass production is easy and can contribute to a request for rationalization.

FIG. 19 shows a part of a different manufacturing process of the diaphragm and the supporting member from the above. This means that, for example, the diaphragm 2b and the support member 6b made of a metal material containing aluminum as a main component are integrally processed and formed by a manufacturing method such as forging, die casting, or shaving. Therefore, in this case, there is no need to join the support member and the diaphragm, and the integrated member of the diaphragm 2b and the support member 6b is simultaneously formed as the insert member 23 with the synthetic resin cylindrical resin case 3 as it is. As a result, the case body 1 can be formed, and there is an advantage that an inter-individual error in characteristics due to individual differences in the joint can be eliminated.

FIG. 20 is a sectional view showing an embodiment in which the support member 6 is completely covered with the resin molding material in the case body 1 formed by simultaneously molding the insert member 23 with the resin case 3. That is, in contrast to FIG. 1, the support member 6 is not completely covered with the resin case 3 but is partially exposed. In this case, when a resin molding material containing at least one type of liquid crystal polymer is used as the resin molding material for forming the resin case 3, the residual vibration of the support member can be further quickly reduced due to the vibration damping characteristics of the liquid crystal polymer. That is, it can be efficiently attenuated. The liquid crystal polymer that can be used is not particularly limited as long as it contributes to solving the above-mentioned problem. For example, an aromatic polyester-type polymer can be suitably used.

[0047]

As described above, in order to solve the above-mentioned problems, the ultrasonic vibrator according to the first aspect of the present invention has a substantially uniform shape having two edges which are linearly symmetric with each other. A vibrating portion made of a metal plate having a large thickness, including a center of gravity of the vibrating portion, and having a plane-symmetric relationship with respect to a plane orthogonal to the vibrating portion and the two edges, and an outer edge of the vibrating portion. A vibration support portion extending in the same direction from two sides facing each other, and an ultrasonic transducer including at least a piezoelectric element disposed on a surface of the vibration portion having the vibration support portion, Since the vibration supporting portion has a structure connected to a supporting member provided around the vibration supporting portion, the vibration of the side surface portion, which is a region near the inner surface inside the case body 1, is suppressed, so that the vibration is provided to the piezoelectric element. It is possible to concentrate on the diaphragm, thereby improving the output sound pressure. It exhibits the excellent effect of that.
In addition to this, after the oscillation of the ultrasonic wave is completed, the mechanical vibration energy remaining on the side surface is reduced, so that the reverberation is shortened, the receiving accuracy of the reflected wave is improved, and the response performance can be improved. I can play.

In the ultrasonic vibrator according to the second aspect of the present invention, a vibrating portion made of a metal plate having a substantially uniform thickness and having two edges which are linearly symmetric with each other, A support including a center of gravity and having a plane-symmetric relationship with respect to a plane orthogonal to the vibrating portion and the two edges, and extending in the same direction from two opposing sides of the outer edge of the vibrating portion. In an ultrasonic vibrator including at least a member and a piezoelectric element disposed on a surface of the vibrating portion on a side having the support member, the supporting member has two sides of an outer edge of the vibrating portion facing each other. In the above, since the vibration portion has an annular structure, the vibration of the side surface portion, which is a region near the inner surface inside the case body, is suppressed, so that the vibration is concentrated on the vibration plate on which the piezoelectric element is disposed. That the output sound pressure can be improved as a result. It exhibits an excellent effect. In addition, after the oscillation of the ultrasonic wave is completed, the mechanical vibration energy remaining on the side surface is reduced, so that the reverberation is shortened, and the reception performance of the reflected wave is improved, and the response performance can be improved. I can play.

According to a third aspect of the present invention, in the ultrasonic transducer according to the first aspect, the vibration supporting portion is joined to the annular support member surrounding the vibration supporting portion. In addition to the effects of the first aspect of the present invention, the diaphragm can be easily formed by punching and bending, and the thickness accuracy of the diaphragm can be easily formed by forming the support member as a separate member from the diaphragm. And it is possible to reduce the inter-individual error in the resonance frequency of the vibration resonance frequency.

According to a fourth aspect of the present invention, in the ultrasonic vibrator according to the first aspect, the vibration support portion is formed integrally with the annular support member. Therefore, in addition to the effect of the first aspect of the present invention, there is no need to join the support member and the diaphragm, and there is no inter-individual error in characteristics due to individual differences in the joining portion, so that a simpler structure can be achieved. It has an excellent effect.

In the ultrasonic vibrator according to the fifth and sixth aspects of the present invention, in the ultrasonic vibrator according to any one of the first to third aspects, the supporting member is connected to the vibrating portion. Since it is made of a metal material having a greater longitudinal elastic modulus than the metal plate to be made, in addition to the effect of the invention according to any one of claims 1 to 3, the length in the direction perpendicular to the diaphragm is shortened. By reducing the thickness of the support member, an excellent effect of further downsizing can be achieved.

In the ultrasonic vibrator according to the seventh aspect of the present invention, in the ultrasonic vibrator according to any one of the first to sixth aspects, the support member is parallel to the two opposing sides and Since it has an external plane orthogonal to the vibrating portion, in addition to the effect of the invention according to any one of claims 1 to 6, the corresponding case body after molding also has the same external plane. It is possible to have a molded body having
Using the outer surface of the case body as a clue, the direction of the ultrasonic sensor can be correctly mounted, and an excellent effect that the directional characteristics of the ultrasonic sensor can be reliably exhibited.

According to an eighth aspect of the present invention, in the ultrasonic vibrator according to the seventh aspect, the portion of the support member having the external plane is more than the other portion of the support member. Since it is characterized in that it is configured to be thick, in addition to the effect of the invention described in claim 7, the rigidity of the annular support member can be further increased, thereby further improving the output sound pressure and the response performance. It has an excellent effect that it can be enhanced.

According to a ninth aspect of the present invention, in the ultrasonic transducer according to any one of the first to eighth aspects, the support member has an upper open edge,
Since the upper open edge is formed at substantially the same height as the diaphragm, the vibration mode of the ultrasonic sensor is added to the effect of the invention according to any one of claims 1 to 8. temperature dependence of the directivity characteristics due to the change, it is possible to reduce the temperature dependence of such resonance frequency, an excellent effect of being able to secure a stable sensor characteristics.

According to a tenth aspect of the present invention, in the ultrasonic vibrator according to any one of the first to ninth aspects, the support member comprises at least one type of liquid crystal polymer. It is characterized by being completely covered with a resin molding material containing the resin material. In addition to the effect of the invention according to any one of claims 1 to 9, the support member remains due to the vibration damping characteristics of the liquid crystal polymer. This provides an excellent effect that vibration can be attenuated more quickly and efficiently.

[Brief description of the drawings]

FIGS. 1A and 1B show a main part of an ultrasonic transducer according to the present invention, in which FIG. 1A is a cross-sectional view cut in a direction without a vibration support part, and FIG. It is sectional drawing.

FIG. 2 is a view showing a part of a manufacturing process of the ultrasonic vibrator according to the present invention, and sequentially showing connection and molding of a diaphragm and a support member.

3A and 3B show a part of a manufacturing process of the ultrasonic vibrator according to the present invention, wherein FIG. 3A is a diagram showing an example of connection between a diaphragm and a support member, and FIG. It is a figure which shows the example of a connection with the support member of a different shape.

FIG. 4 is a diagram showing an example of a usage form of the ultrasonic transducer according to the present invention.

FIGS. 5A and 5B show a mode of joining a diaphragm and a support member of the ultrasonic transducer according to the present invention, wherein FIG. 5A is a cross-sectional view when both are joined at the bottom surface, and FIG. Is a cross-sectional view in a case where the two are joined by a bottom surface and a side surface, and FIG.

FIG. 6 is a view showing a part of a manufacturing process of the ultrasonic vibrator according to the present invention, and is a diagram sequentially showing a diaphragm, a support member, and connection and molding of both.

FIG. 7 is a view showing an ultrasonic vibrator according to the present invention, showing a form of connection of a diaphragm and a support member different from the above and a form after molding.

FIG. 8 is a view showing an ultrasonic vibrator according to the present invention, showing a form of connection of a diaphragm and a support member different from the above and a form after molding.

FIG. 9 is a view showing an ultrasonic vibrator according to the present invention, showing a form of connection between a diaphragm and a support member different from the above and a form after molding.

FIG. 10 is a cross-sectional view of the annular support member constituting the ultrasonic transducer according to the present invention shown in FIG.

FIG. 11 is a view showing an ultrasonic vibrator according to the present invention, showing a form of connection between a diaphragm and a support member different from the above and a form after molding.

FIG. 12 is a view showing an ultrasonic vibrator according to the present invention, showing a form of connection between a diaphragm and a support member different from the above and a form after molding.

FIG. 13 is a cross-sectional view of the annular support member constituting the ultrasonic transducer according to the present invention shown in FIG.

FIG. 14 is a view showing an ultrasonic vibrator according to the present invention, showing a form of connection between a diaphragm and a support member different from the above and a form after molding.

FIG. 15 is a view showing an ultrasonic vibrator according to the present invention, showing a form of connection between a diaphragm and a support member different from the above and a form after molding.

FIG. 16 is a view showing an ultrasonic vibrator according to the present invention, showing a form of connection between a diaphragm and a support member different from the above and a form after molding.

FIG. 17 shows a case body formed by simultaneously molding an insert member of the ultrasonic transducer according to the present invention with a resin case,
The upper open edge of the annular support member after the formation of the insert member is formed at substantially the same height as the diaphragm.
(b) is a cross-sectional view cut in a direction having no d. FIG.
It is sectional drawing cut | disconnected in the direction which has.

FIG. 18 shows a case body formed by simultaneously molding an insert member of the ultrasonic transducer according to the present invention with a resin case,
The upper end of the annular support member has a uniform height,
(a) is a cross-sectional view cut in a direction not having the connection portion 4d,
(b) is a cross-sectional view cut in a direction having a connection portion 4d.

FIG. 19 is a view showing a part of a manufacturing process of the ultrasonic vibrator according to the present invention and sequentially showing different connection forms of the diaphragm and the support member and subsequent forming.

FIG. 20 shows an embodiment in which the support member is completely covered with a resin molding material in the case body of the ultrasonic transducer according to the present invention, and FIG. FIG. 4B is a cross-sectional view taken along a direction including the connecting portion 4d.

FIG. 21 is a diagram illustrating an example of a usage form of an ultrasonic sensor to which an ultrasonic transducer according to a conventional example is applied.

FIGS. 22A and 22B show an ultrasonic transducer according to a conventional example, in which FIG. 22A is a cross-sectional view showing a main part of the configuration, and FIG.

23 (a) is a perspective view showing an essential part of the configuration, FIG. 23 (b) is a cross-sectional view taken along the line AA ′ of FIG. 23 (a), and FIG. Is a cross-sectional view during operation.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 case body 1a open end 1b closing surface 1c side surface portion 2 diaphragm 3 resin case 4 vibrating portion 4a ultrasonic transmitting / receiving surface 4b disposing surface 4c end edge (non-connecting portion) 4d connecting portion 5 vibration supporting portion 6 supporting member 7 piezoelectric Element 8 Lead wire 9 Lead wire 10 Sound absorbing material 11 Filler 12 Opening 13 Ultrasonic sensor 14 Automobile 15 Bumper 16 Case body 16a Closed surface 16b Side surface 17 Metal case 18 Resin case 19 Load resistance 20 Joint 21 Joint 22 Joint Location 23 Insert Member 24 Straight Outer Part 25 Outer Plane 26 Outer Plane 27 Top Open Edge 28 Resin

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kaoru Shibata 1048 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd. (72) Inventor Yusuke Hashimoto 1048 Kadoma Kadoma, Kadoma City, Osaka Matsushita Electric Works F Terms (reference) 5D019 AA01 EE03 FF01 GG09 5D107 AA03 AA16 BB09 CC02 CC10 FF01 FF07 5J083 AA02 AB13 AC16 AC31 AE10 AF09 CA17 CA32 CA35 CA38 CB01

Claims (10)

[Claims] 1. A vibrating portion made of a metal plate having a substantially uniform thickness and having two edges in a line relationship with each other, and a center of gravity of the vibrating portion, wherein the vibrating portion and the two edges are included. Having a plane-symmetric relationship with respect to a plane perpendicular to and having a vibration support portion extending in the same direction from two mutually opposing outer edges of the vibration portion, and the vibration support portion of the vibration portion. An ultrasonic vibrator comprising at least a piezoelectric element disposed on a side surface of the ultrasonic vibrator, wherein the vibration support portion has a structure connected to a support member provided around the ultrasonic vibrator. 2. A vibrating portion made of a metal plate having a substantially uniform thickness and having two edges in a line-symmetrical relationship with each other, a center of gravity of the vibrating portion, and the vibrating portion and the two edges. And a support member extending in the same direction from two mutually opposing sides of the outer edge of the vibrating portion, and a support member of the vibrating portion on the side having the support member. An ultrasonic vibrator having at least a piezoelectric element disposed on a surface, wherein the support member has an annular structure bridged by the vibrating portion on two mutually opposing sides of an outer edge of the vibrating portion. An ultrasonic vibrator characterized in that: 3. The ultrasonic vibrator according to claim 1, wherein said vibration support portion is joined to said annular support member surrounding said vibration support portion. 4. The ultrasonic vibrator according to claim 1, wherein said vibration support portion is formed integrally with said annular support member. 5. The ultrasonic vibration according to claim 1, wherein said support member is made of a metal material having a higher longitudinal elastic modulus than a metal plate forming said vibrating portion. Child. 6. The ultrasonic vibrator according to claim 5, wherein said support member is made of a metal material mainly containing iron, and said vibrating part is made of a metal material mainly containing aluminum. . 7. The ultrasonic transducer according to claim 1, wherein said support member has an external plane parallel to said two opposing sides and orthogonal to said vibrating part. 8. The ultrasonic vibrator according to claim 7, wherein a portion of said support member having said external plane is thicker than other portions of said support member. Wherein said support member comprises an upper open edge, wherein the upper open edge to any one of claims 1 to 8, characterized in that configured in substantially the same height as the diaphragm Ultrasonic transducer. 10. The ultrasonic wave according to claim 1, wherein the support member is completely covered with a resin molding material containing at least one type of liquid crystal polymer. Vibrator.