JP2001078296A - Ultrasonic wave vibrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic wave vibrator that can oscillate an ultrasonic wave with an isotropic directivity and easily be manufactured at a low cost. SOLUTION: A piezoelectric element 8 is placed on an inner face of an enclosed face 1a of a case body 1 whose one end face is open and the other end face is closed in this ultrasonic wave vibrator. The ultrasonic wave vibrator A generates an ultrasonic wave in the enclosed face 1a with an isotropic directivity. The case body 1 consists of a metallic case 2 formed with a metal- made plate 13 and of a resin case 3 made of a synthetic resin material.

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. 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 vibrator 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 the opening provided in the bumper 19 or the like so that the vibrating part 4 is exposed from the bumper 19.
Are arranged so that the thin portions 25 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.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and enables an ultrasonic oscillator having an omnidirectional directional characteristic to be easily manufactured at a low cost. It is an object of the present invention to provide an ultrasonic transducer excellent in design.

[0011]

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.
In the ultrasonic vibrator A in which ultrasonic waves generated on the closed surface 1a have directional characteristics of different directions, the case body 1 is made of a metal case 2 formed from a metal plate material 13.
And a resin case 3 made of a synthetic resin material.

[0012] The invention of claim 2 of the present invention is based on claim 1.
In addition to the configuration described above, the metal case 2 is formed by bending a metal plate 13.

The invention according to claim 3 of the present invention is characterized in that, in addition to the structure of claim 1, a metal case 2 is formed by subjecting a metal plate 13 to a drawing process. is there.

According to a fourth aspect of the present invention, a first aspect is provided.
In addition to any one of the above-described configurations, the vibrating unit 4 includes 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.

Further, the invention of claim 5 of the present invention is directed to claim 4
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.

[0016] The invention of claim 6 of the present invention is characterized by claim 1
In addition to any one of the configurations described above, the vibrating unit 4 includes 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.

[0017] The invention of claim 7 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.

[0018] The invention of claim 8 of the present invention is characterized by claim 1
In addition to any one of the above-described structures, the sheet member 17 is provided on the closed surface 1a of the case body 1.

According to a ninth aspect of the present invention, an eighth aspect is provided.
In addition to the above configuration, the sheet material 1
7, the sheet material 17 is provided on the closed surface 1a.

According to a tenth aspect of the present invention, in addition to the constitution of the eighth or ninth aspect, the outer peripheral edge of the sheet member 17 is extended to the outer peripheral surface of the resin case 3. It is assumed that.

[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. 2, 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.

Next, the ultrasonic transducer A shown in FIG. 3 will be described.

The case body 1 includes a metal case 2 and a resin case 3.

The metal case 2 is formed in a substantially bottomed cylindrical shape. 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.
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 linear shape. Therefore, the vibrating portion 4 is formed in an oval shape. Further, a rib 10 is formed on the outer periphery of the end of the vibration suppressing portion 5 opposite to the vibrating portion 4 so as to protrude outward over the entire circumference.

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 or cutting process is 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. 4, it is formed by drawing a metal plate 13 such as an aluminum plate. That is, first, a disk-shaped metal plate 13 as shown in FIG. 4A is drawn 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. 4 (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.

Next, the ultrasonic transducer A shown in FIG. 5 will be described.

The case body 1 includes 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 its shape is simple, so that a complicated forging process or cutting process is not required. A simple bending process or drawing process can be performed on a single metal plate material 13 to make it cheap and easy. For example, as shown in FIG. 6, one metal plate material 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 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.

The ultrasonic transducer A constructed as shown in FIGS. 1, 3 and 5 applies a pulse voltage between the lead wires 7 and controls a voltage generated between the lead wires 7. 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. When the ultrasonic wave oscillated from the vibrating section 4 is reflected on an obstacle or the like and the reflected wave hits the ultrasonic transmitting / receiving surface 4c of the vibrating section 4, the vibrating section 4
Vibrate, and the piezoelectric element 8 vibrates accordingly. 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 a mounting object such as a bumper of an automobile, the ultrasonic vibrator A is closed in an opening formed in the mounting 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 the pair of connecting portions 4a are vertically arranged, and the pair of non-connecting portions 4b are arranged horizontally.

When an ultrasonic wave is oscillated from the ultrasonic vibrator A, the vibration mode of the vibration part 4 in the horizontal direction (the direction from one non-connection part 4b to the other non-connection part 4b) is a simple bending vibration. However, the vibration mode in the vertical direction (the direction from one connecting portion 4a to the other connecting portion 4a) is easy to bend because the non-connecting 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. That is, the vibration portion 4 has a small amplitude near the connection portion 4a because the connection portion 4a is fixed.
The amplitude in the inner portion sandwiched between them is increased. As a result, the direction of oscillation of the ultrasonic waves generated by the vibration of the vibrating part 4 is sharper without spreading in the vertical direction than in the horizontal direction, and the ultrasonic waves oscillated from the vibrating part 4 are totally horizontal in the horizontal direction. A directivity is provided which has an anomalous direction in which the spread in the vertical direction is widened but narrow in the vertical direction. 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.

Also, since the ultrasonic wave oscillated from the ultrasonic oscillator A 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 mounted on 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 providing the resin case 3 in the ultrasonic transducer A as shown in FIGS. 1, 3 and 5, the resin case 3 is provided in the cavity while the metal case 2 is disposed in the cavity of the molding die. The case body 1 can be produced by integrally molding the resin case 3 with the metal case 2 by insert molding for molding the metal case 2. 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.

Next, the ultrasonic transducer A shown in FIG. 7 will be described. This ultrasonic vibrator A is obtained by providing a sheet member 17 on the ultrasonic vibrator A shown in FIG. The sheet member 17 is preferably formed of a material having excellent weather resistance, and may be formed of, for example, a vinyl chloride resin.
The sheet material 17 is provided so as to cover the entire closed surface 1a of the case 1 of the ultrasonic transducer A. That is, the sheet member 17 includes the vibrating portion 4 of the metal case 2 and the resin case 3.
Is formed in substantially the same shape and dimensions as the closed surface 1a formed by the front surface of the ultrasonic transducer A, and is disposed in alignment with the closed surface 1a of the ultrasonic transducer A.

When the sheet material 17 is provided on the ultrasonic vibrator A as shown in FIG. 7, when the ultrasonic vibrator A is arranged on a mounting object such as a bumper of an automobile, etc.
By providing a sheet material 17 having a color similar to the appearance of the object on the ultrasonic vibrator A, the ultrasonic vibrator A can be arranged on the object with good appearance. Further, the color of the exposed surface of the ultrasonic vibrator A can be more easily matched to the object to be mounted than when the ultrasonic vibrator A is painted. By covering the joint between the resin case 3 and the metal case 2 with the sheet material 17, the ultrasonic vibrator A
Can be improved and the waterproofness can be improved. Here, when the sheet material 17 is provided, if the sheet material 17 and the closed surface 1a of the case body 1 of the ultrasonic transducer A are bonded with an adhesive, the sheet material 17 is securely attached to the closed surface 1a. As a result, the mounting strength of the sheet member 17 can be improved, and the sealing performance of the closing surface 1a can be further improved to further improve the waterproofness.

Next, the ultrasonic transducer A shown in FIG. 8 will be described. This ultrasonic vibrator A is obtained by providing a sheet member 17 on the ultrasonic vibrator A shown in FIG. The sheet member 17 is preferably formed of a material having excellent weather resistance, and may be formed of, for example, a vinyl chloride resin.
The sheet material 17 is provided so as to cover the entire closed surface 1a of the case 1 of the ultrasonic transducer A, and to extend to the side peripheral surface of the case 1 that is continuous with the closed surface 1a. The sheet member 17 includes the vibrating portion 4 of the metal case 2 and the resin case 3.
Is formed in substantially the same shape as the closed surface 1a formed by the front surface of the front surface, and is formed to have a slightly larger size than the closed surface 1a. At the outer edge of the sheet material 17, a plurality of V-shaped cuts 17b are formed over the entire circumference,
The portion sandwiched between the cuts 17b is formed as a folded portion 17a. The portion surrounded by the folded portion 17a is formed to have substantially the same shape and dimensions as the closed surface 1a of the case body 1. When the sheet material 17 is provided on the ultrasonic vibrator A, the folded portion 17 of the sheet material 17 is used.
The portion inside the portion a is aligned with the closing surface 1a of the case body 1, and the folded portion 17a is folded toward the side peripheral surface of the case body 1 that is continuous with the closing surface 1a.

When the sheet material 17 is provided on the ultrasonic vibrator A as shown in FIG. 8, when the ultrasonic vibrator A is disposed on a mounting object such as a bumper of an automobile, etc.
By providing a sheet material 17 having a color similar to the appearance of the object on the ultrasonic vibrator A, the ultrasonic vibrator A can be arranged on the object with good appearance. Further, the color of the exposed surface of the ultrasonic vibrator A can be more easily matched to the object to be mounted than when the ultrasonic vibrator A is painted. By covering the joint between the resin case 3 and the metal case 2 with the sheet material 17, the ultrasonic vibrator A
Can be improved and the waterproofness can be improved. Further, since the sheet member 17 is attached not only to the closed surface 1a but also to the side peripheral surface of the case body 1, the attachment strength of the sheet member 17 is improved. Here, when the sheet material 17 is provided, the sheet material 17 and the closed surface 1a and the side peripheral surface of the case body 1 of the ultrasonic transducer A are bonded with an adhesive, so that the sheet material 17 is
a, the mounting strength of the sheet member 17 can be improved, and the sealing property of the closed surface 1a can be further improved, and the waterproof property can be further improved.

[0053]

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. The case body of a waterproof ultrasonic oscillator that emits ultrasonic waves having directional characteristics of different directions can be formed by molding a metal plate material and a synthetic resin material. An ultrasonic vibrator that does not need to be provided with a horn or the like for controlling directional characteristics can be easily formed at low cost.

The second aspect of the present invention is the first aspect of the present invention.
In addition to the above configuration, a 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 formed.

According to a third aspect of the present invention, in addition to the configuration of the first aspect, a metal plate is subjected to drawing to form a metal case, which involves a forging step and a cutting step. A metal case can be formed without using a metal case, and the metal case can be formed easily at low cost.

Further, the invention of claim 4 of the present invention is directed to claim 1
In addition to the configuration of any one of (1) to (3), the vibration control unit includes a vibration unit having one surface formed as an ultrasonic transmission / reception surface and the other surface formed as an arrangement surface on which the piezoelectric element is arranged, and a vibration suppression unit. 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 5 of the present invention is directed to claim 4
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,
Ultrasonic waves emitted from the vibrating part can be given a directivity with a different direction that spreads in the horizontal direction but narrows in the vertical direction as a whole. Is what you can do. Therefore,
In particular, when used 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.

The invention of claim 6 of the present invention is directed to claim 1
In addition to any one of the above-described structures, a vibrating portion having one surface formed as an ultrasonic transmission / reception surface and the other surface formed as a mounting surface on which a piezoelectric element is provided, and provided from an outer edge of the vibrating portion 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.

Further, the invention of claim 7 of the present invention is directed to claim 1
In addition to any one of the above configurations, 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.

The invention of claim 8 of the present invention provides the method of claim 1
In addition to any one of the above-described structures, a sheet material is provided on the closed surface of the case body, and the sheet material having a color similar to the appearance of the mounting object to which the ultrasonic vibrator is mounted is attached to the ultrasonic vibrator. In this way, the ultrasonic transducer can be disposed on the object with good appearance, and the sealing performance of the ultrasonic transducer can be improved and the waterproof property can be improved. It is.

The invention of claim 9 of the present invention is directed to claim 8
In addition to the above configuration, the sheet material is provided on the closed surface by bonding the sheet material to the closed surface of the case body, so that the sheet material can be securely attached to the closed surface and the mounting strength of the sheet material is improved. In addition, the sealing performance of the closed surface can be further improved, and the waterproofness can be further improved.

According to a tenth aspect of the present invention, in addition to any one of the eighth and ninth aspects, the outer peripheral edge of the sheet material extends to the outer peripheral surface of the resin case. Since it is mounted not only on the closed surface but also on the side peripheral surface of the case body, the mounting strength of the sheet material 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.

FIGS. 2A to 2C are cross-sectional views illustrating steps of manufacturing a metal case according to the embodiment.

FIG. 3 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.

4 (a) to 4 (e) show a manufacturing process of the metal case in the embodiment described above, wherein FIG. 4 (a) is a perspective view and FIGS. 4 (b) to 4 (e) are sectional views.

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.

FIG. 6 is a perspective view showing a metal case in the embodiment.

FIGS. 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, and FIG.

8 shows still another example of the embodiment of the present invention, wherein (a) is a front view, (b) is a side sectional view, and (c) is a bottom sectional view. FIG.

FIGS. 9A and 9B show still another example of the embodiment of the present invention, wherein FIG. 9A is an exploded perspective view and FIG. 9B is a perspective view.

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 17 Sheet material

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoshi Kajiyama 1048 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd. (72) Inventor Ken Takeshi 1048 Kazuma Kazuma, Kadoma City, Osaka Matsushita Electric Works Co., Ltd. (72) Inventor Yusuke Hashimoto 1048 Kadoma Kadoma, Kadoma City, Osaka Prefecture (72) Inventor Takashi Otani 1048 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inventor Matsushita Electric Works Co., Ltd. (72) Masahiko Adachi Kadoma Kadoma, Osaka Prefecture 1048 Matsushita Electric Works Co., Ltd. F-term (reference) 5D019 AA26 BB12 EE01 EE02 FF01 5D107 AA02 BB09 CC01 CC10 DD11

Claims (10)

[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 transducer characterized by comprising: 2. The ultrasonic vibrator according to claim 1, wherein a metal case is formed by bending a metal plate material. 3. The ultrasonic vibrator according to claim 1, wherein a metal case is formed by subjecting a metal plate to a drawing process. 4. 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 claim 1, wherein the ultrasonic vibrator is fixed to a resin case at the portion. 5. A connecting portion and a 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. The ultrasonic vibrator according to claim 4, wherein the non-connecting portions are formed so as to be substantially orthogonal to the arrangement direction. 6. A vibrating portion having one surface formed as an ultrasonic transmitting / receiving surface and the other surface formed as a mounting surface on which a piezoelectric element is mounted, and 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. 6. The ultrasonic transducer according to any one of 1 to 5. 7. 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. 8. The ultrasonic transducer according to claim 1, wherein a sheet material is provided on a closed surface of the case body. 9. The ultrasonic transducer according to claim 8, wherein a sheet material is provided on the closed surface by bonding a sheet material to the closed surface of the case body. 10. The sheet material according to claim 8, wherein an outer peripheral edge of the sheet material is extended to an outer peripheral surface of the resin case.
4. The ultrasonic transducer according to claim 1.