WO2007091609A1

WO2007091609A1 - Ultrasonic sensor

Info

Publication number: WO2007091609A1
Application number: PCT/JP2007/052145
Authority: WO
Inventors: Taku Matsumoto; Junshi Ota; Masanaga Nishikawa
Original assignee: Murata Manufacturing Co., Ltd.
Priority date: 2006-02-10
Filing date: 2007-02-07
Publication date: 2007-08-16
Also published as: JPWO2007091609A1

Abstract

A rectangular ultrasonic sensor excellent in reverberation characteristics and directivity. The ultrasonic sensor (10) comprises case (12) having a bottomed generally-rectangular tube shape composed of a bottom portion (14) having a generally rectangular plate shape and a side surface portion (16) of generally-rectangular tube shape. The thickness of the side surface portion (16) is greater than that of the bottom portion (14). The thickness of the opposed side parts (16a, 16a) of the side surface portion (16) is less than that of the other opposed side parts (16b, 16b) thereof. The inner surface of the parts (16a, 16a) is concave and having a circular-arc cross-section. Therefore, the thickness of the parts (16a, 16a) changes gradually. A piezoelectric element (20) is provided on the bottom portion (14) of the case (12). Signal wires (22a, 22b) of a cable (22) are electrically connected to the piezoelectric element (20), and a capacitor (24) for temperature compensation is parallel connected to the piezoelectric element (20). A sound-absorbing member (26) is disposed on the piezoelectric element (20), and an insulating resin (28) is placed inside the case (12).

Description

Specification

Ultrasonic sensor

Technical field

TECHNICAL FIELD [0001] The present invention relates to an ultrasonic sensor, and more particularly to an ultrasonic sensor used in, for example, a back sonar for an automobile.

Background art

FIG. 10 is a front schematic view showing an example of a conventional ultrasonic sensor, and FIG. 11 is a side schematic view of the ultrasonic sensor. The ultrasonic sensor 1 includes a bottomed substantially quadrangular cylindrical case 2 made of aluminum or the like. Case 2 has a rectangular or oval opening. One surface of the piezoelectric element 3 is bonded to the bottom surface inside the case 2. In addition, one signal line 4a of the cable 4 is soldered to one electrode of the temperature compensating capacitor 5 and also to the inner surface of the case 2. Further, the other signal line 4 b of the cable 4 is soldered to the other electrode of the capacitor 5 and is also soldered to the electrode on the other surface of the piezoelectric element 3. Accordingly, the piezoelectric element 3 and the temperature compensation capacitor 5 are connected in parallel between the signal lines 4a and 4b of the cable 4. On the other surface of the piezoelectric element 3, for example, a sound absorbing material 6 made of felt is disposed. In addition, the case 2 is filled with an insulating resin 7 having a strong force such as silicon rubber or urethane rubber. The insulating resin 7 seals the piezoelectric element 3 and the sound absorbing material 6 in a sealed state, and also insulates the signal lines 4a and 4b from the capacitor 5.

When measuring the distance to the object to be detected using the ultrasonic sensor 1, the piezoelectric element 3 is excited by applying a drive voltage to the signal lines 4 a and 4 b of the cable 4. Due to the vibration of the piezoelectric element 3, the bottom surface of the case 2 also vibrates, and ultrasonic waves are emitted in a direction perpendicular to the bottom surface. When the ultrasonic wave emitted from the ultrasonic sensor 1 is reflected by the object to be detected and reaches the ultrasonic sensor 1, the piezoelectric element 3 vibrates and is converted into an electric signal, and the electric signal is transmitted from the signal lines 4a and 4b of the cable 4. A signal is output. Therefore, the distance from the ultrasonic sensor 1 to the object to be detected can be determined by measuring the time from when the drive voltage is applied until the electrical signal is output. [0004] In this ultrasonic sensor 1, for example, when it is attached to a bumper of an automobile and used as a back sonar for detecting an obstacle, a reverberation characteristic with a small reverberation for detecting an obstacle at a short distance, Furthermore, in order not to detect the ground or curb, vertical and narrow horizontal directions are required, and wide directivity is required. In this ultrasonic sensor 1, in particular, the thickness T1 of the side surface of the case 2 is made larger than the thickness T2 of the bottom surface of the case 2 in order to suppress the vibration of the side surface of the case 2 and reduce reverberation ( (See Patent Document 1).

Patent Document 1: Japanese Patent Laid-Open No. 9 284896

Disclosure of the invention

Problems to be solved by the invention

However, in the rectangular ultrasonic sensor 1 shown in FIG. 10, the inner peripheral surface and the outer peripheral surface of the thin portion of the side surface of the case 2 are parallel to each other. There is a problem that the reverberation characteristic is deteriorated. FIG. 12 shows a graph of the reverberation waveform in the case of using the case 2 made of aluminum, the sound absorbing material 6 made of felt, and the insulating resin 7 also having a silicon rubber force in the rectangular ultrasonic sensor 1.

Therefore, in the rectangular ultrasonic sensor 1 shown in FIG. 10, in order to reduce reverberation, when the thickness of the side surface portion of the case 2 is further increased, the vibration area of the case 2 is reduced, There is a problem that the directivity in the vertical direction becomes wide.

[0008] Therefore, a main object of the present invention is to provide a rectangular ultrasonic sensor excellent in reverberation characteristics and directivity.

Means for solving the problem

[0009] An ultrasonic sensor according to the present invention includes a bottomed substantially quadrangular cylindrical case having a bottom surface portion and a side surface portion, and a piezoelectric element formed on the inner surface of the bottom surface portion of the case. Of the case is formed thicker than the thickness of the bottom surface portion of the case, and the opening of the case is formed longer in the thickness direction of the opposite one side portion of the case side portion, and on the side portion of the case perpendicular to that direction. It is formed shorter in the thickness direction of the opposite other side portion, and the thickness of one side portion in the direction in which the opening is formed longer than the thickness of the other side portion in the direction in which the opening is formed shorter in the side surface portion of the case. The thickness of the case is at least one side of the side of the case.

It is an ultrasonic sensor that is formed to change in a slanting manner!

[0010] In the ultrasonic sensor according to the present invention, the thickness of the other side portion of the side surface portion of the case is also configured to change in an inclined manner in a direction parallel to the main surface of the bottom surface portion of the case. /! I like to do it! /

In the ultrasonic sensor according to the present invention, the thickness of the side surface portion of the case is made larger than the thickness of the bottom surface portion of the case in order to suppress the vibration of the side surface portion of the case and reduce reverberation. In this case, the thickness of at least one thin side portion of the side surface portion of the case is formed so as to change in an inclined manner instead of being uniform, so that vibration of the side surface portion of the case is suppressed and reverberation is reduced. , Reverberation characteristics are improved. As described above, since the reverberation characteristics are improved in the ultrasonic sensor according to the present invention, it is possible to arbitrarily set the thickness of the one side portion having a small thickness on the side surface portion of the case, and the necessary directivity. It becomes easy to obtain.

The reason why reverberation is suppressed when the thickness of the one side portion of the case is formed so as to change in a slanting manner on the side surface portion of the case as in the case of an ultrasonic sensor that is powerful in the present invention is as follows. . In other words, if the thickness of the side surface of the case on both sides in the longitudinal direction of the case opening is uniform and the opposing main surfaces are parallel, the case resonates at the natural vibration frequency determined by the thickness and width. However, this resonance increases the reverberation. On the other hand, the present inventors have found that the reverberation can be suppressed because it does not resonate by changing the thickness of the side surface of the case in an inclined manner like the ultrasonic sensor according to the present invention. It is.

Further, in the ultrasonic sensor that is effective in the present invention, the one side portion having a small thickness on the side surface portion of the case is on both sides in the longitudinal direction of the opening portion of the case, and the thickness V on the side surface portion of the case is increased. By having the side portions on both sides in the short direction of the opening of the case, directivity can be further reduced and reverberation can be further prevented.

[0012] In the ultrasonic sensor according to the present invention, if the thickness of the side surface portion of the case is formed so that the thickness of the other side portion is not uniform and changes in an inclined manner. The vibration of the side surface of the slab is further suppressed, and reverberation is further reduced. The invention's effect

[0013] According to the present invention, a rectangular ultrasonic sensor having excellent reverberation characteristics and directivity can be obtained.

The above-described object, other objects, features, and advantages of the present invention will become more apparent from the following description of the best mode for carrying out the invention with reference to the drawings.

Brief Description of Drawings

[0015] FIG. 1 is an illustrative front view showing an example of an ultrasonic sensor according to the present invention.

FIG. 2 is an illustrative side view of the ultrasonic sensor shown in FIG.

[Fig. 3] Position of the side surface of the case in the ultrasonic sensor shown in Fig. 1 with a non-uniform thickness on the side of the case and the ultrasonic sensor shown in Fig. 10 with a uniform thickness ( It is a graph which shows the simulation result of the displacement amount with respect to (height).

FIG. 4 is a graph showing a reverberation waveform of the ultrasonic sensor shown in FIG.

FIG. 5 shows the vibration of an ultrasonic sensor in which the thickness of the other side portion in the direction in which the opening is formed shorter than the thickness of the one side portion in the direction in which the opening is formed longer on the side surface portion of the case. It is a figure of the simulation which shows a state.

[FIG. 6] Ultrasound in which the thickness of the one side portion in the direction in which the opening is formed long and the thickness of the other side portion in the direction in which the opening is formed short have the same dimensions on the side surface of the case It is a figure of the simulation which shows the vibration state of a sensor.

[FIG. 7] Vibration of an ultrasonic sensor in which the thickness of the other side portion in the direction in which the opening is formed shorter than the thickness of the one side portion in the direction in which the opening is formed longer on the side surface portion of the case It is a figure of the simulation which shows a state.

FIG. 8 is an illustrative front view showing another example of the ultrasonic sensor according to the present invention.

FIG. 9 is a side view of the ultrasonic sensor shown in FIG.

FIG. 10 is an illustration of a front view showing an example of a conventional ultrasonic sensor.

FIG. 11 is a side view of the ultrasonic sensor shown in FIG.

FIG. 12 is a graph showing a reverberation waveform of the ultrasonic sensor shown in FIG.

Explanation of symbols

[0016] 10 Ultrasonic sensor 12 cases

14 Bottom

14a End part

16 Side

16a One side part

16b The other side

18 opening

20 Piezoelectric element

22 Cable

22a, 22b Signal line

24 capacitors

26 Sound absorbing material

28 Insulating grease

BEST MODE FOR CARRYING OUT THE INVENTION

[0017] FIG. 1 is a front schematic view showing an example of an ultrasonic sensor that is useful in the present invention, and FIG. 2 is a side schematic view of the ultrasonic sensor. The ultrasonic sensor 10 includes a case 12 having a substantially quadrangular cylindrical shape with a bottom made of a metal such as aluminum. Case 12 is abbreviated

It is composed of a quadrangular plate-like bottom portion 14 and a substantially quadrangular cylindrical side portion 16. The opening 18 inside the case 12 is formed, for example, in a substantially oval cross section.

That is, in this case 12, the outer shape of the bottom surface portion 14 is formed in a substantially quadrangular shape with four rounded corners of the square, and the outer shape of the side surface portion 16 is also substantially corresponding to the outer shape of the bottom surface portion 14. Formed into a quadrangular shape.

[0019] In this case 12, the thickness T1 of the thinnest portion of the side surface portion 16 is formed to be thicker than the thickness T2 of the bottom surface portion 14. That is, in the case 12, the side surface portion 16 is formed to have a thickness greater than that of the bottom surface portion 14.

Furthermore, in this case 12, the thickness of the one side portions 16a, 16a facing each other at the side surface portion 16 is made thinner than the thickness T3 of the other side portions 16b, 16b facing each other at the side surface portion 16. Therefore, in the side surface portion 16 of the case 12, the opposing one side portions 16a, 16a The thinnest part exists.

[0021] Further, in this case 12, in the side surface portion 16, the inner peripheral surfaces of the thin one side portions 16a, 16a are formed to be recessed in a circular arc shape, and the one side portions 16a, 16a The outer peripheral surface is formed in a flat shape. Accordingly, the thickness of the one side portions 16a, 16a is formed so as to gradually increase from the center which is not uniform toward the other side portions 16b, 16b on both sides, that is, the bottom surface of the case 12. It is formed so as to change in an inclined manner in a direction parallel to the main surface of the portion 14.

[0022] Further, in this case 12, in the side surface portion 16, the inner peripheral surface and the outer peripheral surface of the thicker other side portion 16b, 16b are formed in a flat shape, respectively, and accordingly, the other side portion 16b, The thickness T3 of 16b is formed uniformly.

[0023] Further, in this case 12, the opening 18 is formed long in the thickness direction of the one side portion 16a of the side surface portion 16, and the thickness direction of the other side portion 16b of the side surface portion 16 orthogonal to that direction is short. It is formed.

In the case 12, the piezoelectric element 20 is attached to the inner surface of the bottom surface portion 14. The piezoelectric element 20 is formed by, for example, forming electrodes on both main surfaces of a disk-shaped piezoelectric substrate. The piezoelectric element 20 is bonded to the bottom surface portion 14 with an electrode force conductive adhesive or the like on one main surface side.

[0025] In addition, an intermediate portion of one signal line 22a of the cable 22 is soldered to one electrode of a capacitor 24 for temperature compensation, and a tip portion of the signal line 22a is an inner surface of the side surface portion 16 of the case 12. Soldered to. Further, the intermediate force S of the other signal line 22b of the cable 22 is soldered to the other electrode of the capacitor 24, and the tip of the signal line 22b is soldered to the electrode on the other main surface side of the piezoelectric element 20. The Accordingly, the piezoelectric element 20 and the temperature compensation capacitor 24 are connected in parallel between the signal lines 22a and 22b of the cable 22.

[0026] On the other main surface of the piezoelectric element 20, a sound absorbing material 26 made of felt, for example, is disposed. Further, the inside of the case 12 is filled with an insulating resin 28 having a force such as silicon rubber or urethane rubber. The insulating resin 28 seals the piezoelectric element 20 and the sound absorbing material 26 in a hermetically sealed state, as well as for signal lines 22a and 22b of the cable 22 and for temperature compensation. The capacitor 24 is insulated.

In the ultrasonic sensor 10, the piezoelectric element 20 is excited by applying a drive voltage to the signal lines 22 a and 22 b of the cable 22. Due to the vibration of the piezoelectric element 20, the bottom surface portion 14 of the case 12 also vibrates, and ultrasonic waves are emitted in a direction orthogonal to the bottom surface portion 14. When the ultrasonic wave emitted from the ultrasonic sensor 10 is reflected by the object to be detected and reaches the ultrasonic sensor 10, the piezoelectric element 20 vibrates and is converted into an electric signal, and is transmitted from the signal lines 22a and 22b of the cable 22. An electrical signal is output. Therefore, the distance from the ultrasonic sensor 10 to the object to be detected can be measured by measuring the time from when the drive voltage is applied until the electrical signal is output.

[0028] In the ultrasonic sensor 10, the opening 18 of the case 12 is formed long in the thickness direction of the one side portion 16a of the side surface portion 16 of the case 12, and the other of the side surface portions 16 orthogonal to the direction. Since it is formed short in the thickness direction of the side portion 16b, it is narrow in the thickness direction of the one side portion 16a and wide in the thickness direction of the other side portion 16b, and has directivity. Therefore, when this ultrasonic sensor 10 is used, for example, as a back sonar for an automobile, the thickness direction of the one side portion 16a becomes the vertical direction on the side surface portion 16 of the case 12, and the thickness direction of the other side portion 16b. Are arranged in a horizontal direction.

In this ultrasonic sensor 10, the thickness of the side surface portion 16 of the case 12 is made larger than the thickness of the bottom surface portion 14 of the case 12 in order to suppress the vibration of the side surface portion 16 of the case 12 and reduce reverberation. ing. In this case, the ultrasonic sensor 10 is formed such that the thickness of the one side portion 16a, 16a having a small thickness is not uniform in the side surface portion 16 of the case 12, but is changed in an inclined manner. Vibration of part 16 is suppressed, reverberation is reduced, and reverberation characteristics are improved.

[0030] FIG. 3 shows an ultrasonic sensor 10 shown in FIG. 1 in which the thickness of the thin side of the side surface of the case is made uneven in this way, and the ultrasonic sensor 1 shown in FIG. 10 in which the thickness is made uniform. 6 is a graph showing a simulation result of a displacement amount with respect to a position (height) of a side surface portion of a case. Fig. 3 shows the outline of the ultrasonic sensor 10, 1 using a case made of aluminum with a height of 10mm, a sound absorbing material made of felt, and an insulating grease made of silicon rubber. As is apparent from the graph of FIG. 3, in the ultrasonic sensor 10 shown in FIG. 1 having a non-uniform thickness, the displacement amount is very small over the entire side surface portion 16 of the case 12. On the other hand, in the ultrasonic sensor 1 shown in FIG. 10 in which the thickness is uniform, the amount of displacement in the portion opposite to the piezoelectric element 3 in the side surface portion of the case 2 is very large.

FIG. 4 is a graph showing the reverberation waveform of the ultrasonic sensor 10 of FIG. 1, in which the graph of FIG. 3 shows the result of the displacement. FIG. 12 is the graph of FIG. 11 is a graph showing a reverberation waveform of the ultrasonic sensor 1 of FIG.

From the graph of FIG. 4 and the graph of FIG. 12, it can be seen that, in the ultrasonic sensor 10 shown in FIG. 1, the amplitude of reverberation is reduced in a short time compared to the ultrasonic sensor 1 shown in FIG.

[0034] Further, in this ultrasonic sensor 10, from the above results, the thickness T1 of the thinnest portion of the side surface portion 16 of the case 12 can be set to an arbitrary thickness, so that necessary directivity is obtained. This is easy.

Furthermore, in this ultrasonic sensor 10, the one side portion 16 a having a small thickness on the side surface portion 16 of the case 12 is on both sides in the longitudinal direction of the opening portion 18 of the case 12, and the side surface portion 16 of the case 12 has In addition, since the thickness of the other side portion 16b is on both sides in the short direction of the opening 18 of the case 12, directivity can be further reduced and reverberation can be further prevented.

Furthermore, in this ultrasonic sensor 10, the temperature compensating capacitor 24 is connected in parallel to the piezoelectric element 20, so that the temperature tracking is good and the temperature drift can be reduced.

[0037] In addition, the maximum length in the longitudinal direction of the opening 18 of the case 12 is set to 12 mm, the length in the short direction is set to 6 mm, and the simulation of the vibration state when the thickness of the side surface portions 16 facing each other is changed. Went. FIG. 5 shows the direction in which the opening 18 is formed shorter than the thickness of the one side portion 16a in the direction in which the opening 18 is formed long in the side surface 16 of the case 12 (the minimum thickness is 0.5 mm, for example). FIG. 6 is a simulation diagram showing a vibration state of the ultrasonic sensor 10 in which the thickness of the other side portion 16b is increased to 4 mm, for example. 6 shows the minimum thickness of the one side portion 16a in the direction in which the opening 18 is formed long in the side surface portion 16 of the case 12, and the thickness of the other side portion 16b in the direction in which the opening 18 is formed short. The vibration state of the ultrasonic sensor 10 with the same dimensions, for example, 0.5 mm It is a figure of the simulation shown. Further, FIG. 7 shows the minimum thickness of one side portion 16a in the direction in which the opening 18 is formed longer in the side surface portion 16 of the case 12, for example, the other side in the direction in which the opening 18 is formed shorter than 0.5 mm. FIG. 6 is a simulation diagram showing the vibration state of the ultrasonic sensor 10 in which the thickness of the portion 16b is formed to be thin, for example, 0.25 mm. In FIGS. 5, 6, and 7, the state in which the case 12 is most deformed by vibration is indicated by a solid line, and the state in which the case 12 is not deformed is indicated by a two-dot chain line.

As shown in FIG. 5, when the thickness of the other side portion 16b in the direction in which the opening 18 is formed short in the side surface portion 16 of the case 12 is made larger than the thickness of the one side portion 16a, vibration is generated at the end portion of the case 12. 6 and 7, as shown in FIGS. 6 and 7, the thickness of the other side portion 16b in the direction in which the opening 18 is formed short in the side surface portion 16 of the case 12 is equal to or less than the thickness of the one side portion 16a. If it is formed to have a thickness of 5 mm, vibration will increase at the end of the case 12, and the reverberation will increase due to the vibration.

Further, the displacement amount of the bottom surface portion 14 of the case 12 and the displacement amount near the opening of the side surface portion 16 of the case 12 of each ultrasonic sensor 10 shown in FIGS. The amount of displacement in the vicinity of the opening of the side surface portion 16 of the case 12 relative to the amount of displacement of the bottom surface portion 14 was compared. Here, the amount of displacement is a combination of the amount of displacement in the vertical direction and the amount of displacement in the parallel direction with respect to the bottom surface portion 14 of the case 12. As a result, in the ultrasonic sensor 10 shown in FIG. 5, the displacement near the opening of the side surface portion 16 with respect to the bottom surface portion 14 of the case 12 is as small as 0.067, and the vibration of the side surface portion 16 of the case 12 is the case 12. It was found that there was only a negligible vibration with respect to the vibration of the bottom surface portion 14 of the. On the other hand, in the ultrasonic sensor 10 shown in FIG. 6, the displacement near the opening of the side surface portion 16 with respect to the bottom surface portion 14 of the case 12 is as large as 0.8. Also in the ultrasonic sensor 10 shown in FIG. The amount of displacement near the opening of the side surface portion 16 with respect to the bottom surface portion 14 of 12 is as large as 1.0, and the vibration of the side surface portion 16 of the case 12 generates the same vibration as the side surface portion 14 of the case 12, respectively. I was strong. Thus, the side surface of the case 12 is formed by making the structure in which the thickness of the one side portion 16a in the direction in which the opening 18 is formed long is thinner than the thickness of the other side portion 16b in the direction in which the opening 18 is formed short. It can be seen that the vibration of part 16 can be suppressed and the reverberation can be reduced. FIG. 8 is a front view solution view showing another example of the ultrasonic sensor according to the present invention, and FIG. 9 is a side view solution view of the ultrasonic sensor. In the ultrasonic sensor 10 shown in FIG. 8, compared to the ultrasonic sensor 10 shown in FIG. 1, in the side surface portion 16 of the case 12, the intermediate portion of the inner peripheral surface of the other side portions 16 b and 16 b is recessed in a circular arc shape. It is formed as follows. Accordingly, in the side surface portion 16 of the case 12, the thickness of the intermediate portion of the other side portions 16b, 16b is formed so as to gradually increase from the center toward the one side portions 16a, 16a on both sides, that is, The case 12 is formed so as to change in an inclined manner in a direction parallel to the main surface of the bottom surface portion 14.

Furthermore, in the ultrasonic sensor 10 shown in FIG. 8, in the bottom surface portion 14 of the case 12, the central portion where the piezoelectric element 20 is provided and the thin side portions 16a and 16a of the side surface portion 16 of the case 12 are provided. The thickness of the substantially oval plate-like end portions 14a, 14a between the two is less than the thickness T2 of the central portion of the bottom surface portion 14 of the case 12.

In the ultrasonic sensor 10 shown in FIG. 8, no capacitor is provided, and no capacitor is connected to the signal lines 22a and 22b.

As described above, in the ultrasonic sensor 10 shown in FIG. 8, the thicknesses of the other side portions 16b and 16b having a large thickness in the side surface portion 16 of the case 12 are not uniform as compared with the ultrasonic sensor 10 shown in FIG. Since it is formed so as to change in an inclined manner, vibration of the side surface portion 16 of the case 12 is further suppressed, and reverberation is further reduced.

Furthermore, in the ultrasonic sensor 10 shown in FIG. 8, compared to the ultrasonic sensor 10 shown in FIG. 1, the side surface portion 16 of the case 12 has a thinner one side portion in the bottom surface portion 14 of the case 12. Since the end portions 14a and 14a, which are the portions on the 16a and 16a sides, are formed thin, it is possible to improve characteristics such as directivity and reverberation characteristics.

In each ultrasonic sensor 10 described above, each part is defined by a specific size, shape, arrangement, material, and number, but in the present invention, these may be arbitrarily changed. By changing in this way, characteristics such as directivity and reverberation characteristics may be further improved.

[0045] Further, in each of the ultrasonic sensors 10 described above, the signal lines 22a and 22b are used for electrical connection with the outside. Pin terminals are used for electrical connection with the outside. It's good. Industrial applicability

The ultrasonic sensor according to the present invention is used in, for example, a pack sonar for an automobile.

Claims

The scope of the claims

[1] a substantially quadrangular cylindrical case with a bottom surface and a side surface, and

Comprising a piezoelectric element formed on the inner surface of the bottom surface of the case;

The thickness force of the side surface portion of the case is formed to be thicker than the thickness of the bottom surface portion of the case, and the opening portion of the case is formed longer in the thickness direction of the opposite one side portion of the side surface portion of the case. In the thickness direction of the opposite side portion of the side surface portion of the case orthogonal to each other, it is formed to be short,

In the side surface portion of the case, the thickness of the one side portion in the direction in which the opening is formed long is thinner than the thickness of the other side portion in the direction in which the opening is formed short,

The ultrasonic sensor is formed such that the thickness of at least the one side portion of the side surface portion of the case changes in an inclined manner in a direction parallel to the main surface of the bottom surface portion of the case. .

[2] In the side surface portion of the case, the thickness of the other side portion is in a direction parallel to the main surface of the bottom surface portion of the case! Formed to change in a slanting manner! The ultrasonic sensor according to claim 1.