JP2002112395A - Ultrasonic wave vibrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method that can easily and inexpensively manufacture an ultrasonic wave vibrator having an anisotropic directivity and to provide an ultrasonic wave vibrator that can maintain excellent enclosing performance even for use for a long time. SOLUTION: A piezoelectric element 8 is placed to an inner face of an enclosed face 1a of a case body 1 where one end face is open and the other end face is closed. In the ultrasonic wave vibrator A of a waterproof type having an anisotropic directivity for an ultrasonic wave generated from the enclosing face 1a, the case body 1 consists of a metallic case 2 made of a metal-made plate material 13 and of a resin case 3 made of a synthetic resin material. A coating film 17 is formed to an outer face of the enclosed face 1a of the case body 1 and a coating film 17 coats a joined part between the metallic case 2 and the resin case 3 appearing at the enclosing face 1a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic vibration which can be applied to an ultrasonic sensor used for a vehicle or the like, which oscillates an ultrasonic wave and receives a reflected wave from an obstacle to detect the presence of the obstacle. 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 pulse is oscillated in the air by the ultrasonic sensor, reflected by an obstacle such as a detection target, and reflected by the reflected wave. Is received by an ultrasonic sensor, the received signal is processed, and an alarm or the like is issued.

FIG. 10 shows an attached state of an ultrasonic sensor.
The ultrasonic sensor 20 is mounted on a bumper 19 of an automobile 18. Here, in order to detect an obstacle existing around the bumper 19 and hindering the movement of the car 18 and not to detect an obstacle such as a road surface that does not hinder the movement of the car 18, Therefore, it is necessary to use the ultrasonic sensor 20 having a detection area which is wide in the horizontal direction and narrow in the vertical direction.

[0004] As an ultrasonic sensor 20 having such an omnidirectional directivity characteristic that is wide in the horizontal direction and narrow in the vertical direction with respect to the road surface, there has been conventionally an ultrasonic sensor as shown in FIG. The ultrasonic sensor 20 includes an ultrasonic vibrator A 'for oscillating ultrasonic waves and receiving a reflected wave, and a horn for controlling the directional characteristics of ultrasonic waves in front of the ultrasonic vibrator A'. 21 are provided. The horn 21 is formed as an opening for communicating the ultrasonic vibrator A 'with the outside, and the longitudinal diameter a, the lateral diameter b, and the depth c of the opening are designed to have appropriate dimensions and shapes. It controls the directional characteristics of ultrasonic waves. Here, reference numeral 22 denotes a holding rubber for fixing the ultrasonic transducer A ', and reference numeral 23 denotes a sensor housing. The ultrasonic sensor 20 configured as described above is disposed on the bumper 19 of the automobile 18 so that the horn 21 is opened from the bumper 19 to the outside.

However, the horn 2 shown in FIG.
When the ultrasonic sensor 20 provided with 1 was used, it was easy for rainwater to enter into the horn 21 and for snow and dust to accumulate while the automobile 18 was running. Horn 21
When a foreign object enters the inside, the directional characteristic of the different direction of the ultrasonic wave oscillated from the ultrasonic transducer A 'changes, and the detection area where an obstacle can be detected changes, or the horn 21 changes.
There is a problem in that an internal foreign substance is detected by the ultrasonic sensor 20 and, even though there is no obstacle, it is reported as if there is an obstacle. Further, when the ultrasonic sensor 20 is mounted, the horn 21
Since the horn 21 protrudes from the surface and the opening of the horn 21 is exposed to the outside, there is a problem that the appearance is poor.

Therefore, by providing the ultrasonic transducer A 'itself for generating ultrasonic waves with directivity in different directions,
Attempts have been made to render the horn 21 unnecessary. That is, in the state of attachment to the ultrasonic vibrator A ',
The vibration mode that radiates ultrasonic waves in the horizontal direction with respect to the road surface is different from the vibration mode that radiates ultrasonic waves in the vertical direction. Ultrasonic waves oscillated from the ultrasonic vibrator A ′ have different directivity. Conventionally, as the ultrasonic transducer A ′ having such an omnidirectional directivity to be provided,
The one shown in FIG. 12 has been proposed. The ultrasonic vibrator A 'is formed in a cylindrical shape from metal, and has a concave portion 26 formed from the upper bottom surface to the lower bottom surface. The bottom surface of the concave portion 26 is formed as a vibrating part 4 ′. The vibrating part 4 ′ has a thick part 24 having a large thickness, and is formed on both sides of the thick part 24. A thin portion 25 having a small thickness is formed. In the concave portion 26 of the ultrasonic transducer A ', the piezoelectric element 8 is disposed on the thick portion 24 of the vibrating portion 4' in a state of being electrically connected.
Lead wires 7 are connected to the surface of the piezoelectric element 8 on the side not in contact with the vibrating portion 4 'and the ultrasonic vibrator A', respectively. Then, by applying a voltage between the lead wires 7, the piezoelectric element 8 is vibrated, and the vibrating part 4 'is vibrated accordingly, thereby generating ultrasonic waves from the vibrating part 4'.

[0007] Such an ultrasonic transducer A 'is connected to an automobile 18
When mounting the ultrasonic vibrator A ', the vibrating part 4' of the ultrasonic vibrator A 'is disposed in an opening provided in the bumper 19 or the like so that the vibrating part 4' is exposed from the bumper 19. Are arranged in a horizontal direction.

The horizontal vibration mode of the vibration part 4 'of the ultrasonic transducer A' is a simple bending vibration. On the other hand, in the vertical vibration mode, since the outside of the thick portion 24 is easily bent due to the thin portion 25, the thick portion 24
The thin portion 25 is bent to be pulled by the vibration of
Therefore, the plane vibration is larger than in the horizontal vibration mode. As a result, the direction of oscillation of the ultrasonic waves generated by the vibration of the vibrating portion 4 'is sharper in the vertical direction than in the horizontal direction, and the ultrasonic oscillation is given a directivity having a different direction.

[0009]

However, when the ultrasonic transducer A 'having such a shape is made of metal,
Although it is manufactured by forging, in order to control the directivity of ultrasonic oscillation, the thickness accuracy of the thin portion 25 is important, and therefore, a number of forging steps are required. Also thin part 2
Since the dimensional accuracy of 5 is also demanded, a cutting step is required in addition to the forging step, and there has been a problem that it cannot be manufactured by inexpensive processing means.

The present inventor has proposed an ultrasonic transducer for solving such a problem as disclosed in Japanese Patent Application No. 11-2466.
The ultrasonic transducer described in the specification etc. filed as No. 74 is proposed. This ultrasonic vibrator has a piezoelectric element disposed on the inner surface side of a closed surface of a case body having one end surface opened and the other end surface closed, and the ultrasonic waves generated on the closed surface have different directions. In an ultrasonic vibrator having directivity characteristics, a case body includes a metal case formed of a metal plate and a resin case formed of a synthetic resin material.

However, when the case body is made up of a metal case and a resin case as described above, when the ultrasonic vibrator is used outdoors, the waterproofness between the metal case and the resin case is reduced. Need to secure. For this reason, the present inventors have proposed in the above-mentioned application a configuration in which a sheet material is adhered to the closed surface of the case body to improve waterproofness. It was difficult to maintain the airtightness due to peeling off.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is possible to easily and inexpensively manufacture an ultrasonic oscillator having an omnidirectional directivity, and it can be used for a long time. It is an object of the present invention to provide an ultrasonic vibrator that can maintain excellent hermeticity and is excellent in design.

[0013]

According to a first aspect of the present invention, there is provided an ultrasonic vibrator in which a piezoelectric element is provided on an inner surface side of a closed surface of a case body having an open end and a closed end. 8 in the ultrasonic transducer A in which the ultrasonic waves generated on the closed surface 1a have directional characteristics of different directions.
The case body 1 includes a metal case 2 formed from a metal plate 13 and a resin case 3 formed of a synthetic resin material.
A metal case 2 and a resin case 3 which form a coating film 17 on the outer surface side of the closed surface 1a of the case body 1 and appear on the closed surface 1a
Is coated with a coating film 17.

According to a second aspect of the present invention, a first aspect is provided.
In addition to the above configuration, a coating film 17 is formed from the outer surface side of the closed surface 1a of the case body 1 to the outer surface of the case body 1.

[0015] The invention of claim 3 of the present invention is characterized by claim 1
Alternatively, in addition to the structure of 2, the metal case 2 is formed by bending a metal plate 13.

The invention according to claim 4 of the present invention is characterized in that, in addition to the structure of claim 1 or 2, the metal case 2 is formed by subjecting a metal plate material 13 to drawing. Things.

Further, the invention of claim 5 of the present invention is directed to claim 1
In addition to any one of the above-described configurations, the vibrating unit 4 has one surface formed as an ultrasonic transmitting / receiving surface 4c and the other surface formed as an arrangement surface 4d on which the piezoelectric element 8 is arranged, and a vibration suppressing unit. And at least one pair of connecting portions 4 where the vibrating portion 4 and the vibration suppressing portion 5 are directly connected to the outer edge of the vibrating portion 4.
a, and the metal case 2 formed with at least a pair of non-connection portions 4 b to which the vibration portion 4 and the vibration suppression portion 5 are not directly connected are fixed to the resin case 3 in the vibration suppression portion 5. It is characterized by the following.

The invention of claim 6 of the present invention provides the method of claim 5
In addition to the configuration described above, a connection portion 4a and a non-connection portion 4b are alternately formed on the outer edge of the vibration portion 4 of the metal case 2 to form a pair of connection portions 4a and a pair of non-connection portions 4b. The arrangement is such that the arrangement direction of the connection portions 4a and the arrangement direction of the non-connection portions 4b are substantially orthogonal to each other.

Further, the invention of claim 7 of the present invention is directed to claim 1
6, a vibrating part 4 having one surface formed as an ultrasonic transmission / reception surface 4c and the other surface formed as an arrangement surface 4d on which the piezoelectric element 8 is arranged. And a vibration suppressing portion 5 extending from the outer edge of the metal case 2 toward the arrangement surface 4d.
The resin case 3 having an arrangement portion 6 opening on the front and back surfaces, and the vibration suppressing portion 5 of the metal case 2 on the inner surface of the arrangement portion 6.
And an opening on the front side of the disposing portion 6 is closed by the vibrating portion 4 of the metal case 2 to form a closed surface 1a by the front surface of the resin case 3 and the ultrasonic transmitting / receiving surface 4c of the vibrating portion 4. It is characterized by being held as described above.

[0020] The invention of claim 8 of the present invention is directed to claim 1.
In addition to any one of the above-described structures, the case body 1 is formed by integrally molding the resin case 3 with the metal case 2 by insert molding.

[0021]

Embodiments of the present invention will be described below.

First, the ultrasonic transducer A shown in FIG. 1 will be described.

The case body 1 is composed of a metal case 2 and a resin case 3.

The metal case 2 includes a vibrating section 4 and a vibration suppressing section 5.
It is composed of The vibrating portion 4 is formed in a rectangular plate shape having a substantially uniform thickness, one surface is formed as an ultrasonic transmission / reception surface 4c, and the other surface is formed as an arrangement surface 4d on which the piezoelectric element 8 is arranged. ing. The vibration suppressing portion 5 extends from each of a pair of opposing sides of the four sides forming the outer edge of the vibrating portion 4 toward the arrangement surface 4d.
That is, of the four sides forming the outer edge of the vibrating part 4,
A pair of opposing sides is formed as a connecting part 4a directly connected to the vibration suppressing part 5, and another pair of opposing sides is a non-connecting part 4b not directly connected to the vibration suppressing part 5. The connecting portion 4a and the non-connecting portion 4 alternately formed along the outer edge of the vibrating portion 4.
b is arranged such that the arrangement direction of the connection portions 4a and the arrangement direction of the non-connection portions 4b are substantially orthogonal to each other.

The metal case 2 does not need to be designed in thickness to form a thin portion or a thick portion, and has a simple shape, so that a complicated forging process and a cutting process are not required. A simple bending process and a drawing process can be performed on a single metal plate member 13 so that it can be easily manufactured at low cost. For example, as shown in FIG. 3, a rectangular parallelepiped bending jig 14 is provided on the upper surface of a metal plate 13 such as an aluminum plate.
Is formed by bending both sides of the plate 13 upward along the bending jig 14 in a state where is disposed, and a portion disposed below the bending jig 14. Are bent upward along the vibrating portion 4 and the bending jig 14 to form a vibration suppressing portion 5.

The resin case 3 is formed of a synthetic resin material having high rigidity and excellent vibration damping properties. This resin case 3 has a circular shape on the front surface and a circular shape on the rear surface with a larger diameter than the front surface. The outer peripheral surface connecting the front and rear surfaces has a larger diameter on the rear side than on the front side. The step 5a is formed so as to be as follows. The resin case 3 is formed with through-holes in the front-rear direction that are open at the front and back surfaces, and the inside of the through-hole is configured as an arrangement portion 6 in which the metal case 2 is arranged. The inner peripheral shape of the disposing portion 6 is formed in a rectangular shape having substantially the same size and shape as the outer edge shape of the vibrating portion 4 of the metal case 2.

The metal case 2 is provided on the arrangement portion 6 of the resin case 3.
The metal case 2
The vibrating portion 4 is arranged such that the front side opening of the disposing portion 6 of the resin case 3 is closed and the ultrasonic transmission / reception surface 4c of the vibrating portion 4 is substantially flush with the front surface of the resin case 3. Front surface of resin case 3 and ultrasonic transmitting / receiving surface 4 of vibrating part 4
At c, a closed surface 1a is formed. The pair of vibration suppressing portions 5 are arranged in close contact with the inner surface of the arrangement portion 6, and are fixed to the resin case 3 on the inner surface of the arrangement portion 6. For this reason, of the four sides constituting the outer edge of the arrangement portion 6, the pair of connecting portions 4 a is fixed to the resin case 3, and the pair of non-connecting portions 4
b is easy to bend without being fixed.

The piezoelectric element 8 is arranged so as to be electrically connected to the arrangement surface 4d of the vibration section 4. Lead wires 7 are connected to the vibration suppressing portion 5 of the metal case 2 and the surface of the piezoelectric element 8 on the side not connected to the arrangement surface 4d, respectively.

Further, a coating film 17 is formed over the entire outer surface of the closed surface 1a of the case body 1. This coating 1
The paint for forming 7 is not particularly limited, and an appropriate paint that can form the water-resistant coating film 17 can be used. As a specific example, for example, a product name “SOFLEX” manufactured by Kansai Paint Co., Ltd. can be used.

When the coating film 17 is formed on the ultrasonic vibrator A in this manner, when the ultrasonic vibrator A is mounted on a mounting object such as a bumper of an automobile, a color similar to the appearance of the object is obtained. The ultrasonic vibrator A can be disposed on an object with good appearance by forming the coating film 17 having the same on the ultrasonic vibrator A. In addition, by covering the joint between the resin case 3 and the metal case 2 with the coating film 17, the hermeticity of the ultrasonic vibrator A is improved and the ultrasonic vibrator A can be made excellent in waterproofness. Further, when a sheet material is adhered to the closed surface 1a, if a part of the sheet material is peeled off, the whole is peeled off in a chain, and it is difficult to maintain waterproofness for a long period of time. When the coating film 17 is formed as described above, even if a part of the coating film 17 is peeled off, the whole is not peeled off in a chain, and the waterproofness of the ultrasonic vibrator A is reliably maintained for a long time. Is what you can do.

In forming the coating film 17 on the ultrasonic vibrator A, as shown in FIG. 2, not only the outer surface side of the closed surface 1a but also the gap between one end surface and the other end surface of the case body 1 is formed. The coating film 17 can also be formed on the outer side surface. When the coating film 17 is formed from the closed surface 1a of the case body 1 to the outer surface in this manner, the edge of the coating film 17 where peeling easily occurs is not disposed on the outer edge of the closed surface 1a, and the closed surface 1a In this case, the peeling of the coating film 17 can be effectively prevented, and the waterproofness can be maintained more reliably. In addition, when the sheet material is stuck from the closed surface 1a to the outer surface, when one sheet material is turned from the closed surface 1a of the case body 1 to the outer surface, a fold or a seam is formed on the outer surface. And the appearance deteriorates.
Is formed, such folds and seams are not formed, and a good appearance can be maintained.

Next, the ultrasonic transducer A shown in FIGS.

The case body 1 is composed of a metal case 2 and a resin case 3.

The metal case 2 is formed in a substantially cylindrical shape with a bottom. The bottom of the metal case 2 is formed as a vibrating part 4. The vibrating part 4 is formed to have a substantially uniform thickness. One surface is formed as an ultrasonic transmitting / receiving surface 4c, and the other surface is formed as an arrangement surface 4d on which the piezoelectric element 8 is arranged. Further, the side surface portion extends from the outer edge of the vibrating section 4
It is formed as a vibration suppressing portion 5 extending toward the d side. An opening 9 communicating between the inside and outside of the metal case 2 is formed at a portion where the vibration section 4 and the vibration suppression section 5 are connected. The opening 9 is formed in a shape in which a part where the vibration part 4 and the vibration suppression part 5 are connected is partially cut away. The two openings 9 are formed substantially symmetrically with respect to a plane perpendicular to the vibrating part 4 that cuts both sides of the metal case 2, and the vibrating part 4 of the opening 9 is formed.
The outer edge portion on the side is formed substantially point-symmetric with respect to the center of the vibrating portion 4. That is, a portion of the outer edge of the vibrating portion 4 adjacent to the opening 9 is formed as a pair of linear non-connecting portions 4b that are not directly connected to the vibration suppressing portion 5,
The portions other than the non-connection portions 4b are formed as a pair of arc-shaped connection portions 4a directly connected to the vibration suppressing portion 5, and the connection portions alternately formed along the outer edge of the vibration portion 4. The portion 4a and the non-connection portion 4b are arranged such that the direction in which the connection portions 4a are arranged and the direction in which the non-connection portions 4b are arranged are substantially orthogonal. The connecting portion 4a is formed in an arc shape, and the non-connecting portion 4b is formed in a straight line. Therefore, the vibrating portion 4 is formed in an oval shape. Further, on the outer periphery of the end of the vibration suppressing portion 5 opposite to the vibrating portion 4, a rib 10 protruding outward over the entire periphery is formed.

The metal case 2 does not need to be designed with a thickness to form a thin portion or a thick portion, and has a simple shape, so that a complicated forging process and a cutting process are not required. A simple bending process and a drawing process can be performed on a single metal plate member 13 so that it can be easily manufactured at low cost. For example, as shown in FIG. 6, it is formed by drawing a metal plate 13 such as an aluminum plate. That is, first, a disk-shaped metal plate material 13 as shown in FIG. 6A is subjected to drawing and formed into a bottomed cylindrical shape having a flange 15. This drawing process is shown in FIG.
As shown in (d), the drawing is performed through three stages of drawing processes of shallow drawing, medium drawing, and deep drawing. Then, as shown in FIG. 6 (e), a punch 16 is formed at the connection between the bottom and the peripheral surface.
Drilling is performed at two places using a pair of openings 9.
Is formed, and the metal case 2 is formed by cutting the flange 15 portion while leaving the portion to be the rib 10.

The resin case 3 is formed of a synthetic resin material having high rigidity and excellent vibration damping properties. This resin case 3 has a circular shape on the front surface and a circular shape on the rear surface with a larger diameter than the front surface. The outer peripheral surface connecting the front and rear surfaces has a larger diameter on the rear side than on the front side. The step 5a is formed so as to be as follows. The resin case 3 is formed with through-holes in the front-rear direction that are open at the front and back surfaces, and the inside of the through-hole is configured as an arrangement portion 6 in which the metal case 2 is arranged. The inner peripheral shape of the disposing portion 6 is formed to have a substantially circular cross section having substantially the same shape and dimensions as the outer peripheral surface shape of the vibration suppressing portion 5 of the metal case 2.

The metal case 2 is provided on the arrangement portion 6 of the resin case 3.
The metal case 2
The vibrating portion 4 is disposed so as to close the opening on the front side of the disposing portion 6 of the resin case 3 and that the ultrasonic transmission / reception surface 4 c of the vibrating portion 4 is substantially flush with the front surface of the resin case 3. In addition, the pair of vibration suppression units 5 are arranged closely to the inner surface of the arrangement unit 6,
The inner surface of the arrangement portion 6 is fixed to the resin case 3. Therefore, a pair of connecting portions 4 in the outer edge of the arrangement portion 6
"a" is fixed to the resin case 3, and the pair of non-connection portions 4b are not fixed but are easily bent. In addition, here
A projection 12 projecting from the opening 9 of the metal case 2 toward the inside of the metal case 2 protrudes from an opening on the side closed by the vibrating portion 4. The opening on the side closed by the portion 4 is formed in an oval shape having substantially the same shape and dimensions as the vibrating portion 4. A rib receiving portion 11 having a shape corresponding to the rib 10 of the metal case 2 is provided on the inner periphery of the opening of the disposing portion 6 opposite to the side closed by the vibrating portion 4 over the entire periphery. Has been established.

The piezoelectric element 8 is arranged so as to be electrically connected to the arrangement surface 4d of the vibration section 4. Lead wires 7 are connected to the vibration suppressing portion 5 of the metal case 2 and the surface of the piezoelectric element 8 on the side not connected to the arrangement surface 4d, respectively.

In the case shown in FIG. 4, the coating film 17 is formed over the entire closed surface 1a of the case body 1 as in the case shown in FIG. As shown in FIG. 2, a coating film 17 is formed on the entire surface from the outer surface of the closed surface 1a to the outer surface of the case body 1 as in the case shown in FIG.

Next, the ultrasonic vibrator A shown in FIGS.

The case body 1 is composed of a metal case 2 and a resin case 3.

The metal case 2 includes a vibrating section 4 and a vibration suppressing section 5.
It is composed of The vibrating portion 4 is formed in a rectangular plate shape having a substantially uniform thickness, one surface is formed as an ultrasonic transmission / reception surface 4c, and the other surface is formed as an arrangement surface 4d on which the piezoelectric element 8 is arranged. ing. The vibration suppressing portion 5 extends from the outer edge of the vibrating portion 4 toward the arrangement surface 4d, and is formed in a cylindrical shape. Here, an opening 9 communicating between the inside and outside of the metal case 2 is provided between a pair of opposing sides of the four sides constituting the outer edge of the vibrating section 4 and the vibration suppressing section 5. Therefore, the pair of sides is formed as the non-connection portions 4b of the vibration suppressing portion 5 which are not directly connected. The other pair of opposing sides is a connecting portion 4 a directly connected to the vibration suppressing portion 5.
Respectively. That is, the connecting portions 4 a and the non-connecting portions 4 alternately formed along the outer edge of the vibrating portion 4.
b is arranged such that the arrangement direction of the connection portions 4a and the arrangement direction of the non-connection portions 4b are substantially orthogonal to each other.

The metal case 2 does not need to be designed in thickness to form a thin portion or a thick portion, and has a simple shape. It can be manufactured easily and inexpensively by subjecting a single metal plate 13 to simple bending or drawing. For example, as shown in FIG. 9, one metal plate 13 is bent and formed. It is formed by doing. That is, as the plate member 13, a total of 4 from the both ends in the longitudinal direction of the rectangular main plate 13a toward both sides.
One formed by extending the sub-plates 13b is used.
The main plate 13a is bent in a U-shape, the bent portions at both ends are formed as the vibration suppressing portions 5 and the portion sandwiched between the vibration suppressing portions 5 is formed as the vibrating portion 4. This bending is performed inside the portion where the sub-plate 13b is formed. At this time, the two pairs of sub-plates 13b are arranged so as to face each other. Further, the sub-plate 13b is bent toward the opposing sub-plate 13b, and the ends of the opposing sub-plates 13b abut each other.
At this time, on the outer edge of the vibrating portion 4, a connection portion 4a is formed at a fold portion of the main plate 13a, and the other portion is formed as a non-connection portion 4b. An opening 9 communicating the inside and the outside of the metal case 2 is formed in a portion surrounded by the non-connection portion 4b and the outer edge of the portion formed by the sub-plate 13b of the vibration suppressing portion 5.
Is formed.

The resin case 3 is formed of a synthetic resin material having high rigidity and excellent vibration damping properties. This resin case 3 has a circular shape on the front surface and a circular shape on the rear surface with a larger diameter than the front surface. The outer peripheral surface connecting the front and rear surfaces has a larger diameter on the rear side than on the front side. The step 5a is formed so as to be as follows. The resin case 3 is formed with through-holes in the front-rear direction that are open at the front and back surfaces, and the inside of the through-hole is configured as an arrangement portion 6 in which the metal case 2 is arranged. The inner peripheral shape of the disposing portion 6 is formed in a substantially rectangular cross section having substantially the same shape and dimensions as the outer peripheral surface shape of the vibration suppressing portion 5 of the metal case 2.

The metal case 2 is provided on the arrangement portion 6 of the resin case 3.
The metal case 2
The vibrating portion 4 is disposed so as to close the opening on the front side of the disposing portion 6 of the resin case 3 and that the ultrasonic transmission / reception surface 4 c of the vibrating portion 4 is substantially flush with the front surface of the resin case 3. The vibration suppressing portion 5 is arranged in close contact with the inner surface of the arrangement portion 6, and is fixed to the resin case 3 on the inner surface of the arrangement portion 6. Therefore, of the outer edges of the arrangement portion 6, the pair of connecting portions 4a are fixed to the resin case 3, and the pair of non-connecting portions 4b are not fixed and are easily bent. Here, the opening 1 on the side closed by the vibrating portion 4 of the disposing portion 6 has a protruding portion 1 protruding from the opening 9 of the metal case 2 toward the inside of the metal case 2.
2 are protruding.

The piezoelectric element 8 is arranged so as to be electrically connected to the arrangement surface 4 d of the vibrating section 4. Lead wires 7 are connected to the vibration suppressing portion 5 of the metal case 2 and the surface of the piezoelectric element 8 on the side not connected to the arrangement surface 4d, respectively.

In FIG. 7, as in the case shown in FIG. 1, the coating film 17 is formed over the entire closed surface 1a of the case body 1, and as shown in FIG. As shown in FIG. 2, a coating film 17 is formed on the entire surface from the outer surface of the closed surface 1a to the outer surface of the case body 1 as in the case shown in FIG.

The ultrasonic transducer A constructed as shown in FIGS. 1, 2, 4, 5, 7, and 8 applies a pulse voltage between the lead wires 7 and generates a pulse voltage between the lead wires 7. By connecting a control circuit that measures the voltage to be applied, the device can be configured as an ultrasonic sensor. Then, when a pulse voltage is applied between the lead wires 7, the piezoelectric element 8 vibrates, and the vibrating part 4 vibrates accordingly to oscillate ultrasonic waves. Further, the ultrasonic wave oscillated from the vibrating part 4 is reflected on an obstacle or the like, and when the reflected wave hits the ultrasonic transmitting / receiving surface 4c of the vibrating part 4, the vibrating part 4 vibrates, and the piezoelectric element 8 vibrates accordingly. I do. At this time, an electromotive force is generated in the piezoelectric element 8, and by detecting the electromotive force between the lead wires 7,
The presence or absence of an obstacle can be detected.

When such an ultrasonic vibrator A is mounted on an object to be mounted, such as a bumper of an automobile, the ultrasonic vibrator A is inserted into an opening formed in the object, and the case body 1 is closed at the opening 9. It is arranged so that the surface 1a is exposed to the outside. At this time, in particular, when the ultrasonic vibrator A is mounted on a vehicle bumper or the like for a vehicle, the closed surface 1
a is arranged substantially perpendicular to the horizontal plane,
Are arranged so that a pair of connecting portions 4a are arranged in a horizontal direction, and a pair of non-connecting portions 4b are arranged so as to be arranged in a vertical direction.

When ultrasonic waves are oscillated from the ultrasonic vibrator A, the vibration mode in the horizontal direction (the direction from one connecting portion 4a to the other connecting portion 4a) in the vibrating portion 4 is a simple bending vibration. The vibration mode in the vertical direction (the direction from one non-connection portion 4b to the other non-connection portion 4b) is easy to bend because the non-connection portion 4b is not fixed to the resin case 3; The plane vibration is greater than the vibration mode in the direction, and even if the vibration section 4 is formed in a flat plate shape having a substantially uniform thickness, a plurality of types of vibration modes can be generated in the vibration section 4. As a result, the oscillating direction of the ultrasonic wave generated by the vibration of the vibrating part 4 becomes sharper without spreading in the vertical direction than in the horizontal direction, and becomes sharper.
The ultrasonic wave oscillated from the antenna is provided with a directivity having a different direction in which the spread in the horizontal direction as a whole but the spread in the vertical direction is narrowed. Accordingly, the detection area of the ultrasonic transducer A 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 transducer A is used especially for a vehicle, it is possible to prevent the detection of an object that does not hinder the movement of the vehicle, such as a road surface.

Since the ultrasonic wave oscillated from the ultrasonic oscillator A itself has directivity having a different direction, the directivity of the ultrasonic wave from the ultrasonic oscillator A in the forward direction which is the oscillation direction of the ultrasonic wave is increased. It is not necessary to provide a horn or the like for providing the ultrasonic vibrator A without forming a depression or the like in front of the ultrasonic vibrator A.
Can be directly exposed to the outside, preventing foreign matters such as rainwater, snow, dust and the like from accumulating in front of the ultrasonic transducer A. Ultrasonic waves oscillated from the ultrasonic transducer A by such foreign substances can be prevented. It can prevent changes in the directional characteristics and malfunctions of the sound waves in different directions, and can change the detection area where obstacles can be detected. It is possible to prevent such a situation as notifying.

When the ultrasonic vibrator A is attached to the object to be mounted, the closed surface 1a of the case body 1 can be disposed so as to be flush with the surface of the object to be mounted. Thus, the appearance in the mounted state can be improved without protruding from the surface of the mounting object or exposing the opening to the outside.

In the ultrasonic vibrator A as shown in FIGS. 1, 2, 4, 5, 7, and 8, when the resin case 3 is provided, the metal case 2 is disposed in the cavity of the molding die. The case body 1 can be manufactured by integrally molding the resin case 3 with the metal case 2 by insert molding for molding the resin case 3 in the cavity. By doing so, the case body 1 can be manufactured at the same time as the resin case 3 is formed, and the manufacturing steps of the ultrasonic vibrator A can be reduced. The connection between the vibrating portion 4 of the metal case 2 and the connecting portion 4 a of the metal case 2 can be stably fixed to the resin case 3 by improving the adhesion to the inner surface of the arrangement portion 6 of the resin case 3. Stability can be improved.

[0054]

As described above, in the ultrasonic vibrator according to the first aspect of the present invention, the piezoelectric element is disposed on the inner side of the closed surface of the case body having one open end and the other open end. And
In an ultrasonic vibrator in which ultrasonic waves generated on the closed surface have directional characteristics of different directions, a case body is composed of a metal case formed of a metal plate material and a resin case formed of a synthetic resin material. Then, a coating film is formed on the outer surface side of the closed surface of the case body, and the joint between the metal case and the resin case that appears on the closed surface is coated with the coating film, and has a super-directional characteristic of a different direction. The case body of a waterproof ultrasonic oscillator that emits sound waves can be formed by molding a metal plate and a synthetic resin material, and there is no need to provide a horn or the like for controlling the directional characteristics of the ultrasonic waves. An ultrasonic vibrator can be formed easily at low cost,
In addition, when the ultrasonic vibrator is disposed on a mounting object such as a bumper of an automobile, a coating film having a color similar to the appearance of the object is formed on the ultrasonic vibrator, and the ultrasonic vibrator is formed. It can be arranged on the object with good appearance. In addition, by covering the joint between the resin case and the metal case with a coating film, the sealing property of the ultrasonic vibrator is improved, and the waterproof property can be improved.
Even if a part of the coating film is peeled off, the whole is not peeled off in a chain, so that the waterproofness of the ultrasonic vibrator A can be reliably maintained for a long time.

The invention of claim 2 of the present invention is directed to claim 1
In addition to the above configuration, a coating film is formed from the outer surface side of the closed surface of the case body to the outer surface of the case body, and the edge of the coating film that is easily peeled may be arranged at the outer edge of the closed surface. In addition, it is possible to effectively prevent the peeling of the coating film on the closed surface, and to more reliably maintain the waterproofness, and to use the sheet material adhered from the closed surface to the outer surface. In the case, when one sheet material is turned from the closed surface of the case body to the outer surface, a fold or a seam is formed on the outer surface, and the appearance is deteriorated,
When forming a coating film, such folds and seams are not formed, and a good appearance can be maintained.

The third aspect of the present invention provides the first aspect.
Or, in addition to the configuration 2, the metal case is formed by bending a metal plate material, and the metal case can be formed without a forging process or a cutting process. It can be easily formed.

According to a fourth aspect of the present invention, in addition to the constitution of the first or second aspect, a metal plate is subjected to drawing to form a metal case, and a forging step or a cutting step is performed. Accordingly, the metal case can be formed without causing the problem, and the metal case can be formed easily at low cost.

Further, the invention of claim 5 of the present invention provides the method of claim 1
In addition to the configuration of any one of (1) to (4), the vibrating section includes one surface formed as an ultrasonic transmission / reception surface and the other surface formed as a surface on which the piezoelectric element is disposed, and a vibration suppressing portion. On the outer edge of the vibrating part, at least one pair of connecting parts where the vibrating part and the vibration suppressing part are directly connected, and at least one pair of non-connecting parts where the vibrating part and the vibration suppressing part are not directly connected are formed. The metal case is to be fixed to the resin case at the vibration suppression part, and the non-connection part is fixed to the resin case to suppress vibration near the non-connection part in the vibration part,
Even if the vibrating part is formed in a flat plate shape with a substantially uniform thickness, it is possible to make the ultrasonic waves emitted from the vibrating part have anisotropic directivity by generating a plurality of vibration modes in the vibrating part. It is.

The invention of claim 6 of the present invention provides the method of claim 5
In addition to the configuration described above, the connecting portion and the non-connecting portion are alternately formed on the outer edge of the vibrating portion of the metal case to form a pair of connecting portions and a pair of non-connecting portions, and the arrangement direction of the connecting portions. And the direction of arrangement of the non-connection portions are substantially orthogonal to each other, and the vibration portion has a small amplitude near the connection portion because the connection portion is fixed, and instead, the vibration portion is between the connection portions. The amplitude in the sandwiched inner part becomes large, and the oscillation direction of the ultrasonic wave generated by the vibration of the vibrating part becomes sharper without spreading in the vertical direction than in the horizontal direction,
The ultrasonic wave emitted from the vibrating part can be given a directivity having an anomalous direction that spreads in the horizontal direction but narrows in the vertical direction as a whole, and can further improve the transmission output. You can do it. Therefore, when used especially for 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.

Further, the invention of claim 7 of the present invention is directed to claim 1
In addition to the configuration of any one of (a) to (c), a vibrating part whose one surface is formed as an ultrasonic transmitting / receiving surface and the other surface is formed as a mounting surface on which a piezoelectric element is provided, and which is provided from an outer edge of the vibrating unit A metal case is constituted by the vibration suppressing portion extending toward the surface side, and the metal case is formed on a resin case having a disposing portion opening at the front surface and the rear surface, and a vibration suppressing portion of the metal case is formed on the inner surface of the disposing portion. And the opening on the front side of the disposing portion is closed by the vibrating portion of the metal case, and the front surface of the resin case and the ultrasonic transmitting / receiving surface of the vibrating portion are held so as to form a closed surface. By exposing the ultrasonic transmitting / receiving surface to the closed surface, the ultrasonic wave can be efficiently oscillated from the closed surface, and the metal transmitting case is disposed inside the resin case to eliminate the ultrasonic transmitting / receiving surface. Metal case and this The piezoelectric element electrically connected to the metal case can be protected from the surroundings, the operation stability of the ultrasonic vibrator can be improved, and the vibration suppressor of the metal case is attached to the resin case. The metal case can be firmly held and the metal case can be firmly held by the resin case.

The invention of claim 8 of the present invention provides the method of claim 1
In addition to any one of the above structures, the case body is formed by integrally molding the resin case with the metal case by insert molding, and the case body can be produced at the same time as the resin case is formed. The manufacturing process of the vibrator can be reduced, and the adhesion between the vibration suppression part of the metal case and the inner surface of the placement part of the resin case is improved. Thus, the operation stability of the ultrasonic vibrator can be improved.

[Brief description of the drawings]

FIG. 1 shows an example of an embodiment of the present invention,
(A) is a front view, (b) is a side sectional view, (c) is a bottom sectional view, and (d) is a rear view.

FIG. 2 shows another example of the embodiment of the present invention,
(A) is a front view, (b) is a side sectional view, (c) is a bottom sectional view, and (d) is a rear view.

FIGS. 3A to 3C are cross-sectional views illustrating steps of manufacturing a metal case in the embodiment.

4A and 4B show still another example of the embodiment of the present invention, wherein FIG. 4A is a front view, FIG. 4B is a side sectional view, FIG. 4C is a bottom sectional view, and FIG. FIG.

5A and 5B show still another example of the embodiment of the present invention, in which FIG. 5A is a front view, FIG. 5B is a side sectional view, FIG. 5C is a bottom sectional view, and FIG. FIG.

6 (a) to 6 (e) show a manufacturing process of the metal case in the embodiment described above, wherein FIG. 6 (a) is a perspective view and FIG. 6 (b) to FIG. 6 (e) are sectional views.

7A and 7B show still another example of the embodiment of the present invention, wherein FIG. 7A is a front view, FIG. 7B is a side sectional view, FIG. 7C is a bottom sectional view, and FIG. FIG.

8A and 8B show still another example of the embodiment of the present invention, wherein FIG. 8A is a front view, FIG. 8B is a side sectional view, FIG. 8C is a bottom sectional view, and FIG. FIG.

FIG. 9 is a perspective view showing a metal case in the embodiment.

FIG. 10 is a perspective view showing an attached state of the ultrasonic sensor to the automobile.

11A and 11B show an example of the prior art, in which FIG. 11A is a side sectional view and FIG. 11B is a front view.

FIGS. 12A and 12B show another example of the prior art, in which FIG. 12A is a front view, and FIG. 12B is a sectional view of a bottom surface.

[Explanation of symbols]

 A Ultrasonic vibrator 1 Case body 2 Metal case 3 Resin case 4 Vibrating part 4a Connecting part 4b Non-connecting part 4c Ultrasonic transmitting / receiving surface 4d Arranging surface 5 Vibration suppressing part 6 Arranging part 8 Piezoelectric element 13 Plate material 17 Coating film

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoshi Kajiyama 1048 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd. 72) Inventor Takashi Otani 1048 Kazuma Kadoma, Osaka Pref.Matsushita Electric Works, Ltd. (72) Inventor Masahiko Adachi 1048 Odaka Kazuma, Kadoma, Osaka Pref. EE01 EE04 FF01

Claims (8)

[Claims] 1. A piezoelectric element is provided on an inner surface side of a closed surface of a case body having one end surface opened and the other end surface closed,
In an ultrasonic vibrator in which ultrasonic waves generated on the closed surface have directional characteristics of different directions, a case body is composed of a metal case formed of a metal plate material and a resin case formed of a synthetic resin material. An ultrasonic vibrator characterized in that a coating film is formed on the outer surface side of the closed surface of the case body and a joint between the metal case and the resin case that appears on the closed surface is coated with the coated film. 2. The ultrasonic transducer according to claim 1, wherein a coating film is formed from an outer side of the closed surface of the case body to an outer side surface of the case body. 3. The ultrasonic transducer according to claim 1, wherein a metal case is formed by bending a metal plate material. 4. The ultrasonic vibrator according to claim 1, wherein a metal case is formed by subjecting a metal plate to a drawing process. 5. A vibrating portion, one surface of which is formed as an ultrasonic transmitting / receiving surface and the other surface of which is formed as a mounting surface on which a piezoelectric element is provided, and a vibration suppressing portion. The metal case formed with at least one pair of connection parts where the vibration part and the vibration suppression part are directly connected, and at least one pair of non-connection parts where the vibration part and the vibration suppression part are not directly connected, The ultrasonic vibrator according to any one of claims 1 to 4, wherein the ultrasonic vibrator is fixed to the resin case at the portion. 6. A pair of connecting portions and a pair of non-connecting portions are formed alternately on the outer edge of the vibrating portion of the metal case to form a pair of connecting portions and a pair of non-connecting portions. The ultrasonic transducer according to claim 5, wherein the ultrasonic transducer is formed so that a direction in which the non-connection portions are arranged is substantially orthogonal to each other. 7. A vibrating portion, one surface of which is formed as an ultrasonic transmitting and receiving surface and the other surface of which is formed as a mounting surface on which a piezoelectric element is mounted, and a portion extending from an outer edge of the vibrating portion toward the mounting surface. A metal case is configured with the output vibration suppression unit, and the metal case is arranged in a resin case having an arrangement portion that opens on the front and back surfaces, and the outer surface of the vibration suppression portion of the metal case is arranged on the inner surface of the arrangement portion. An opening on the front side of the disposing portion is closed by a vibrating portion of the metal case, and the front surface of the resin case and the ultrasonic transmitting / receiving surface of the vibrating portion are held so as to form a closed surface. 7. The ultrasonic vibrator according to any one of 1 to 6. 8. The ultrasonic transducer according to claim 1, wherein a case body is formed by integrally molding a resin case with a metal case by insert molding.