Ultrasonic sensor device and vehicle

Abstract

To provide an ultrasonic sensor device having a wide horizontal directivity and an extremely narrow vertical directivity.SOLUTION: An ultrasonic sensor is provided with a bottomed cylindrical case. The case includes a first thin wall section, a first thick wall section having a first protrusion, a second thin wall section, and a second thick wall section having a second protrusion. The first and second thin wall sections face each other. The first and second thick wall sections face each other. All or a part of the first and second protrusions is curved in line symmetry with respect to an X axis. DX is equal to or longer than 20.5% of B and DY is equal to or longer than 34.1% of B, DX representing the lengths of the first and second protrusions on the X axis, DY representing the lengths on a Y axis at midpoints of the lengths of the first and second protrusions on the X axis, and B representing the length of opening from the first thin wall section to the second thin wall section.SELECTED DRAWING: Figure 5A

Description

[Technical Field]

[0001] The present disclosure relates to an ultrasonic sensor device that transmits and / or receives ultrasonic waves, and a vehicle. [Background technology]

[0002] BACKGROUND ART Conventionally, ultrasonic sensors that are attached to the rear end of a vehicle to detect obstacles behind the vehicle are known (for example, Patent Document 1).

[0003] The ultrasonic sensor in Patent Document 1 includes a cylindrical case with a bottom, a piezoelectric element, a pair of lead wires, and a filler. The piezoelectric element is installed on the inner bottom surface of the case, and the filler seals the case. The pair of lead wires supplies power to the piezoelectric element. The inner diameter of the cylindrical case with a bottom has two protrusions facing each other, and each protrusion has a tip. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2016 / 189858 Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved by the present disclosure is to provide an ultrasonic sensor device that has wide directivity in the horizontal direction and extremely narrow directivity in the vertical direction. [Means for solving the problem]

[0006] An ultrasonic sensor device according to one embodiment of the present disclosure includes a cylindrical case with a bottom. The case has a first thin-walled portion formed along the inner wall surface of the case, a first thick-walled portion having a first protrusion protruding from the inner wall surface of the case toward the internal space of the case, a second thin-walled portion formed along the inner wall surface of the case, and a second thick-walled portion having a second protrusion protruding from the inner wall surface of the case toward the internal space of the case. In a cross section parallel to the inner bottom surface of the case, the first thin-walled portion and the second thin-walled portion face each other, and the first thick-walled portion and the second thick-walled portion face each other. The X-axis passes through the center of the case in a direction in which wide-angle directivity is desired for the directional characteristics of the ultrasonic sensor device. The Y-axis passes through the center of the case in a direction in which narrow-angle directivity is desired for the directional characteristics of the ultrasonic sensor device. All or part of the first protrusion and the second protrusion have a curved shape that is line-symmetrical with respect to the X-axis. When the length on the X-axis of each of the first protrusion and the second protrusion is DX, the length on the Y-axis at the midpoint of the length on the X-axis of each of the first protrusion and the second protrusion is DY, and the opening length of the internal space of the case from the first thin wall portion to the second thin wall portion is B, DX has a length of 20.5% or more of B, and DY has a length of 34.1% or more of B. [Brief explanation of the drawings]

[0007] [Figure 1A] FIG. 1 is a perspective view of an ultrasonic device according to an embodiment of the present invention. [Figure 1B] 1 is a cross-sectional view of an ultrasonic device according to an embodiment of the present invention. [Figure 1C] 1C is a cross-sectional view of a cross section perpendicular to the cross section of FIG. 1B in the present embodiment. [Figure 2A] FIG. 2 is a top view of a case of the ultrasonic device according to the present embodiment. [Figure 2B] FIG. 2 is a side view of a case of the ultrasonic device according to the present embodiment. [Figure 2C] FIG. 2 is a front view of a case of the ultrasonic device according to the present embodiment. [Figure 2D] FIG. 2 is a perspective view of a case of the ultrasonic device according to the present embodiment. [Figure 3]FIG. 2 is a cross-sectional view of a case of the ultrasonic device according to the present embodiment. [Figure 4A] FIG. 1 is a block diagram of an ultrasonic sensor according to an embodiment of the present invention. [Figure 4B] FIG. 10 is a block diagram of another ultrasonic sensor according to the present embodiment. [Figure 4C] 1 is a schematic diagram of a vehicle equipped with an ultrasonic sensor according to an embodiment of the present invention; [Figure 5A] FIG. 1 is a perspective view of an ultrasonic device according to a first modified example of the present embodiment. [Figure 5B] FIG. 10 is a cross-sectional view of an ultrasonic device according to a first modified example of the present embodiment. [Figure 6A] FIG. 10 is a perspective view of an ultrasonic device according to a second modification of the present embodiment. [Figure 6B] FIG. 10 is a cross-sectional view of an ultrasonic device according to a second modification of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0009] (Embodiment) It is desirable for the ultrasonic sensor to have a wide horizontal transmission and reception range for ultrasonic waves to detect obstacles far from the vehicle, and a narrow vertical directivity to prevent detection of reflections from the ground or ceiling.

[0010] However, with conventional ultrasonic sensors, when the ultrasonic output is increased to detect obstacles at a long distance from the rear end of the vehicle, the vertical detection range also becomes large, and the sensor detects reflections from the ground or ceiling. There is a demand for an ultrasonic device that improves on the above points, having wide directivity in the horizontal direction and extremely narrow directivity in the vertical direction.

[0011] In the past, in such ultrasonic devices, it was desirable to have a vertical half-value angle of 35 degrees or less when the horizontal half-value angle was 63 degrees or more, and a vertical half-value angle of 41 degrees or less when the horizontal half-value angle was 80 degrees or more; in other words, it was required to achieve a flattening ratio (horizontal half-value angle ÷ vertical half-value angle) of 2 or more.

[0012] However, in recent years, there has been an increasing demand for even higher flatness. For example, there are many cases where a flatness of 2.5 or more and a vertical half-power angle of 35 degrees or less are required. Thus, there is a demand for an ultrasonic device that can achieve wide directivity in the horizontal direction and even narrower directivity in the vertical direction.

[0013] Fig. 1A is a perspective view of ultrasonic device 11 according to an embodiment. Fig. 1B is a cross-sectional view of ultrasonic device 11 according to an embodiment. Fig. 1C is a cross-sectional view of an embodiment taken along a line perpendicular to the cross-section of Fig. 1B. In Fig. 1A, dashed lines are hidden lines that indicate parts that are hidden and cannot be seen.

[0014] An ultrasonic device 11 according to the present disclosure includes a cylindrical case 12 with a bottom, a piezoelectric element 13, lead wires 14, and a filler 15. The piezoelectric element 13 is disposed on the inner bottom surface of the case 12. The lead wires 14 are connected to the piezoelectric element 13. The filler 15 seals the case 12.

[0015] Case 12 has a first thin wall portion 21A and a first thick wall portion 22A. First thin wall portion 21A is formed along the inner wall surface of case 12. First thick wall portion 22A has a first protrusion 24A that protrudes from the inner wall surface of case 12 toward the internal space of case 12.

[0016] Case 12 has a cylindrical shape with a bottom, and includes bottom 16 and tubular portion 17. Case 12 is formed of a metal such as aluminum. Bottom 16 is a vibration surface that emits ultrasonic waves, and includes inner bottom surface 19 and outer bottom surface 20. Tube portion 17 includes a pair of opposing thin wall portions 21 and a pair of opposing thick wall portions 22. That is, in FIG. 1A , tubular portion 17 includes first thin wall portion 21A and second thin wall portion 21B. First thin wall portion 21A and second thin wall portion 21B are formed along the inner wall surface of case 12.

[0017] Furthermore, the tubular portion 17 has a first thick wall portion 22A and a second thick wall portion 22B. The first thick wall portion 22A has a first protrusion 24A that protrudes from the inner wall surface of the case 12 toward the internal space of the case 12. The second thick wall portion 22B has a second protrusion 24B that protrudes from the inner wall surface of the case 12 toward the internal space of the case 12.

[0018] The outer shape of the first protrusion 24A includes a first ellipse 25A with a center point 28A, and a first tangent line 26A-1 that contacts the ellipse 25A at a tangent point 27A-1 and a second tangent line 26A-2 that contacts the first ellipse 25A at a tangent point 27A-2 have shapes that expand toward the outer periphery.

[0019] The outer shape of the second protrusion 24B includes a second ellipse 25B with a center point 28B, and a first tangent line 26B-1 that meets the second ellipse 25B at a tangent point 27B-1 and a second tangent line 26B-2 that meets the second ellipse 25B at a tangent point 27B-2 have shapes that expand toward the outer periphery.

[0020] Here, the first thin wall portion 21A and the second thin wall portion 21B are collectively referred to as the thin wall portion 21. The first thick wall portion 22A and the second thick wall portion 22B are collectively referred to as the thick wall portion 22. The first protrusion 24A and the second protrusion 24B are collectively referred to as the protrusion 24. The first ellipse 25A and the second ellipse 25B are collectively referred to as the ellipse center point 28A and the second ellipse center point 28B are collectively referred to as the ellipse center point 28. The first tangent 26A-1 and the second tangent 26A-2 of the first ellipse 25A and the first tangent 26B-1 and the second tangent 26B-2 of the second ellipse 25B are collectively referred to as the tangent 26.

[0021] The thin wall portion 21 is a portion with a relatively thin wall thickness, and has a substantially arcuate shape and a substantially constant wall thickness. Here, the thickness of the thin wall portion 21 is preferably within a range of ±10% or less of the average thickness of the thin wall portion 21.

[0022] The piezoelectric element 13 is a source of ultrasonic vibrations fixed to the inner bottom surface 19 of the case 12, and has a piezoelectric body (not shown) and electrodes (not shown) provided on both sides thereof. The pair of lead wires 14 is made of a conductor. Electrodes (not shown) are formed on both sides of the piezoelectric element 13. At least one of the lead wires 14 is connected to one electrode of the piezoelectric element 13. Power is supplied to the piezoelectric element 13 through the pair of lead wires 14.

[0023] The filler 15 is made of a resin material such as a foamed silicone resin, and seals the piezoelectric element 13 inside the case 12 .

[0024] Next, the structure of case 12 will be described with reference to Figures 2A to 2D and 3. Figure 2A is a top view of case 12 of ultrasonic device 11 according to the embodiment. Figure 2B is a side view of case 12 of ultrasonic device 11 according to the embodiment.

[0025] Fig. 2C is a front view of case 12 of ultrasonic device 11 according to the embodiment. Fig. 2D is a perspective view of case 12 of ultrasonic device 11 according to the embodiment. Fig. 3 is a cross-sectional view of case 12 of ultrasonic device 11 according to the embodiment. Fig. 3 roughly corresponds to a cross-sectional view of tubular portion 17 of case 12 when case 12 is cut along a plane parallel to inner bottom surface 19.

[0026] 2A and 1C, the case 12 has a center point 23. Furthermore, as shown in FIGS. 1A and 2A to 2C, an X direction, a Y direction, and a Z direction are defined in the ultrasonic device 11.

[0027] 2A, the location where the piezoelectric element 13 is placed relative to the inner bottom surface 19 of the case 12 is indicated by a rectangular dashed line. The piezoelectric element 13 is placed so that the center of the inner bottom surface 19 of the case 12 and the center of the piezoelectric element 13 are approximately aligned.

[0028] As shown in FIG. 3, the dimensions of case 12 are represented by the outer diameter A of cylindrical portion 17, the opening length B of thin-wall portion 21, the minimum opening length C of thick-wall portion 22, the wall thickness D of thin-wall portion 21, the diameter DX of the ellipse in the X direction of thick-wall portion 22, the diameter DY of the ellipse in the Y direction of thick-wall portion 22, and the length LC in the X direction from tangent point 27 where ellipse 25 and tangent line 26 meet to the center line of the ellipse.

[0029] FIG. 4A is a block diagram of an ultrasonic sensor 30 according to this embodiment. FIG. 4B is a block diagram of another ultrasonic sensor 30 according to this embodiment. The ultrasonic sensor 30 includes an ultrasonic device 11, a wave-transmitting circuit 71, and a housing case 73. The ultrasonic device 11 is used as an ultrasonic transducer. The wave-transmitting circuit 71 drives the ultrasonic device 11 to generate ultrasonic waves. The housing case 73 holds the ultrasonic device 11 and the wave-transmitting circuit 71.

[0030] 4B, the housing case 73 may hold only the ultrasonic device 11. In other words, the housing case 73 may be configured to hold at least the ultrasonic device 11.

[0031] 4C is a schematic diagram of a vehicle 31 equipped with an ultrasonic sensor 30 according to this embodiment. The ultrasonic sensor 30 detects the presence of obstacles around the vehicle 31 and the distance to the obstacles by emitting ultrasonic waves and receiving reflected ultrasonic waves.

[0032] 1A, the X and Y directions of the ultrasonic device 11 are horizontal, and the Z direction is vertical. However, when the ultrasonic device 11 is mounted on the vehicle 31, the Y direction of the ultrasonic device 11 is set to the up-down direction (i.e., the approximately vertical direction) and the X direction is set to the left-right direction (i.e., the approximately horizontal direction).

[0033] That is, the ultrasonic device 11 is installed so that the X and Z directions are approximately horizontal to the ground, and the Y direction is approximately vertical. Here, the direction in which ultrasonic waves are transmitted or received is the Z direction.

[0034] By setting the direction of the ultrasonic device 11 and defining the shape of the ultrasonic device 11 in this way, it is possible to control the directivity in the horizontal direction while ensuring narrow directivity in the vertical direction.

[0035] The Z direction may be at a slight angle relative to the horizontal direction of the vehicle 31. The Y direction may also be at a slight angle relative to the vertical direction. Furthermore, the direction in which ultrasonic waves are transmitted or received may be tilted slightly upward or downward from the horizontal.

[0036] Here, the directivity of the ultrasonic device 11 refers to the directivity of the ultrasonic reception sensitivity when the ultrasonic device 11 is used to receive ultrasonic waves, and refers to the directivity of the ultrasonic radiation intensity when the ultrasonic device 11 is used to transmit ultrasonic waves.

[0037] Table 1 shows the evaluation results of the examples examined in this embodiment.

[0038] In Examples 1 to 50 shown in Table 1, the outer diameter A of the cylindrical portion 17 is 15.5 mm. The opening length B of the thin-walled portion 21 is 14.62 mm. The wall thickness D of the thin-walled portion 21 is 0.44 mm. The minimum opening length C of the thick-walled portion 22 is 6.6 mm. The diameter DX in the X direction of the ellipse 25 of the protruding portion 24 of the thick-walled portion 22 is 2.0 mm or more and 8.0 mm or less, and the diameter in the Y direction is 3.0 mm or more and 9.0 mm or less. The tangent 26 of the ellipse 25 forming the protruding portion 24 has a contact point 27 on the ellipse 25 that is a distance (denoted as LC) of 0.8 mm in the X direction from the center line passing through the center point 28 of the ellipse 25.

[0039] However, if the contact point 27 cannot be located inside the thin wall portion 21 of the cylindrical portion 17, the shape of the protrusion 24 may be a shape consisting of only the ellipse 25.

[0040] [Table 1]

[0041] Table 1 shows the dimensions DX and DY of case 12, and the vertical directivity angle, horizontal directivity angle, and flattening ratio (horizontal directivity angle ÷ vertical directivity) at half the maximum output (-6 dB) when ultrasonic waves were emitted. All of Nos. 1 to 50 had a flattening ratio of more than 2.5, with examples with a flattening ratio of more than 2.5 being rated "G (Good)" and examples with a vertical directivity angle of 35 degrees or less being rated "E (Excellent)." In other words, simply including an ellipse 25 in the outer shape of protrusion 24 results in a good flattening ratio.

[0042] Also, (Table 2) is (Table 1) rearranged on the DX and DY axes.

[0043] [Table 2]

[0044] From (Table 2), it was found that the good directivity characteristic "E" depends on DX and DY. Good directivity angle characteristics can be obtained when DX is 3.0 mm or more, that is, has a length of 20.5% or more of the opening length B of the thin-walled portion 21, and DY is 5.0 mm or more, that is, has a length of 34.1% or more of the opening length B of the thin-walled portion 21.

[0045] Furthermore, when examining the distribution of "E", it was found that it is concentrated in a range of 2 mm, that is, 13.6% of the opening length B of the thin-walled portion 21, mainly when the relationship of a linear function where the slope of DY with respect to DX is 0.5 and the offset is 4.0 mm, that is, 27.3% of the opening length B of the thin-walled portion 21, holds.

[0046] When expressed by a mathematical formula, a more vertically narrow-angle directivity can be obtained when the relationship of DY - B×0.136 < (DX×0.5 + B×0.273) < DY + B×0.136 is satisfied.

[0047] (Modification Example 1) Note that the outer shapes of the first protruding portion 24A and the second protruding portion 24B are not limited to ellipses. As shown in FIGS. 5A and 5B, they may be parabolas. The first tangent line 26C-1 and the second tangent line 26C-2 of the parabola have a shape that spreads toward the outer periphery. Here, the outer shapes of the first protruding portion 24A and the second protruding portion 24B may be quadratic curves, the outer shape may be a circle, or the outer shapes of the first protruding portion 24A and the second protruding portion 24B may be hyperbolas. Also, at least one of the outer shapes of the first protruding portion 24A and the second protruding portion 24B may be a quadratic curve shape.

[0048] (Modification Example 2) Also, there may be cases where the tips of the first protruding portion 24A and the second protruding portion 24B are flat. In FIGS. 6A and 6B, the protruding portion tip portions 40A and 40B of the protruding portions 24A and 24B are flat, and the protruding portion side wall portions 41A-1, 41A-2 and 41B-1, 41B-2 of the protruding portions 24A and 24B may be quadratic curves 25A and 25B, and cases of circles, ellipses, hyperbolas, or parabolas are conceivable. Also, there may be cases where the lead wire 14 is joined to the protruding portion 24A or the protruding portion 24B.

[0049] In the present embodiment, the thickness of the first thick wall portion 22A and the second thick wall portion 22B does not change in the Z direction of the ultrasonic device 11, but the present disclosure is not limited to this. In the ultrasonic device of the present disclosure, the thickness of the thick wall portion may change partway in the Z direction, or the thick wall may disappear partway. It is sufficient that at least a portion of the ultrasonic device in the Z direction forms a thick wall portion.

[0050] The ultrasonic device of the present disclosure includes a cylindrical case 12 with a bottom, a piezoelectric element 13, lead wires 14, and a filler 15. The piezoelectric element 13 is installed on an inner bottom surface 19 of the case 12. The lead wires 14 are connected to the piezoelectric element 13. The filler 15 seals the case 12.

[0051] Case 12 has a first thin wall portion 21A, a first thick wall portion 22A, a second thin wall portion 21B, and a second thick wall portion 22B. First thin wall portion 21A and second thin wall portion 21B are formed along the inner wall surface of case 12. First thick wall portion 22A has a first protrusion 24A that protrudes from the inner wall surface of case 12 toward the internal space of case 12. Second thick wall portion 22B has a second protrusion 24B that protrudes from the inner wall surface of case 12 toward the internal space of case 12.

[0052] In addition, the first thick wall portion 22A has a first protrusion 24A that protrudes from the inner wall surface of the case 12 toward the internal space of the case 12, and the second thick wall portion 22B has a second protrusion 24B that protrudes from the inner wall surface of the case 12 toward the internal space of the case 12.

[0053] The outer shape of the first protrusion 24A includes a first ellipse 25A, and its first tangent line 26A-1 and second tangent line 26A-2 have shapes that widen toward the outer periphery. The outer shape of the second protrusion 24B includes a second ellipse 25B, and its first tangent line 26B-1 and second tangent line 26B-2 have shapes that widen toward the outer periphery.

[0054] Assume the direction for obtaining wide directivity is the X direction, the direction for obtaining narrow directivity is the Y direction, the diameter in the X direction of ellipse 25A or ellipse 25B is DX, the diameter in the Y direction is DY, and the opening length of the thin-walled portion 21 is B. Then, DX has a length of 20.5% or more of B, and DY satisfies a length of 34.1% or more of B.

[0055] Furthermore, when DX and DY satisfy the relationship of DY - B×0.136 < (DX×0.5 + B×0.273) < DY + B×0.136, a narrower directivity in the Y direction can be obtained.

[0056] As described above, the ultrasonic device 11 of this embodiment has a piezoelectric element 13 on the inner bottom surface 19 of the bottomed cylindrical case 12. And the cylindrical portion 17 of the case 12 has, in a cross-section parallel to the inner bottom surface 19 of the case 12, a thin-walled portion 21 whose inner wall surface is a substantially arc shape centered on the center point 23 of the case 12, and a thick-walled portion 22 having a wall thickness thicker than that of the thin-walled portion 21 and whose inner wall surface protrudes toward the inner space of the case.

[0057] By including the ellipse 25 in the shape of the protruding portion 24, a directivity design exceeding the conventional directivity level becomes possible. As a result, while ensuring a wide directivity in the X direction, an extremely narrow directivity in the Y direction can be realized. By equipping the vehicle 31 with the ultrasonic sensor 30 provided with the ultrasonic device 11 as an ultrasonic transducer and using it for detecting obstacles, the influence caused by reflections from the road surface or from the ceiling of a garage or the like can be reduced, and detection with a wide directivity in the horizontal direction becomes possible.

[0058] For example, obstacles behind the vehicle can be accurately detected. Further, when a narrower directivity in the Y direction is required, it is desirable that the diameter DX in the X direction of the ellipse 25 has a length of 20.5% or more of the opening length B of the thin-walled portion 21, and the diameter DY in the Y direction has a length of 34.1% or more of the opening length B of the thin-walled portion 21.

[0059] Also, when DX and DY satisfy the relationship of DY - B×0.136 < (DX×0.5 + B×0.273) < DY + B×0.136, a narrower directivity in the Y direction can be obtained.

[0060] In this embodiment, the thickness of the thin wall portion 21 is set to be approximately constant, but it is also possible for it to be a thickness that is not approximately constant. For example, the thickness of the thin wall portion 21 may be inclined. With the above configuration, the ultrasonic device and ultrasonic sensor of the present disclosure have a wide directivity in the horizontal direction, while having an extremely narrow directivity in the vertical direction. [Explanation of symbols]

[0061] 11 Ultrasonic devices 12 cases 13 Piezoelectric element 14 Lead wire 15 Filler 16 Bottom 17 Cylinder part 19 Inner bottom surface 20 Outer bottom surface 21 Thin wall section 21A First thin-walled section 21B Second thin-walled section 22 Thick wall section 22A First Thick Wall 22B Second thick wall section 23 Center point 24 Protrusion 24A First protrusion 24B Second protrusion 25 oval 25A First Oval 25B Second ellipse 26 tangent 26A-1, 26B-1 First tangent 26A-2, 26B-2 First tangent 27 Contacts 27A-1 Contact 27B-1 Contact 28A-1 Contact 28B-1 Contact 28 Ellipse Center Point 28A First ellipse center point 28B Second ellipse center point 30 Ultrasonic Sensor 31 vehicles 71 Transmitting circuit 73 Housing Case A Outside diameter B Opening length C Minimum opening length D Wall thickness DX diameter DY diameter

Claims

1. It has a cylindrical case with a bottom, The case includes a first thin wall portion formed along an inner wall surface of the case; a first thick wall portion having a first protrusion protruding from an inner wall surface of the case toward an internal space of the case; a second thin wall portion formed along an inner wall surface of the case; a second thick wall portion having a second protrusion protruding from an inner wall surface of the case toward an internal space of the case, In a cross section parallel to an inner bottom surface of the case, the first thin wall portion and the second thin wall portion face each other, and the first thick wall portion and the second thick wall portion face each other, a direction passing through the center of the case and in which wide-angle directivity is desired for the directional characteristics of the ultrasonic sensor device is defined as an X-axis, and a direction passing through the center of the case and in which narrow-angle directivity is desired for the directional characteristics of the ultrasonic sensor device is defined as a Y-axis; all or a part of the first protrusion and the second protrusion have a curved shape that is line-symmetric with respect to the X-axis, a length on the X-axis of each of the first protrusion and the second protrusion is defined as DX, and a length on the Y-axis at a midpoint of the length on the X-axis of each of the first protrusion and the second protrusion is defined as DY; In the internal space of the case, when an opening length from the first thin wall portion to the second thin wall portion is defined as B, DX has a length of 20.5% or more of B, and DY has a length of 34.1% or more of B. Ultrasonic sensor device.

2. the shapes of the first protrusion and the second protrusion include a curve that is line-symmetric with respect to the X-axis and two tangent lines that are tangent to the curve that is line-symmetric with respect to the X-axis, and the two tangent lines expand toward the outer periphery of the case; The ultrasonic sensor device according to claim 1 .

3. The DX and the DY The relationship DY−B×0.136<(DX×0.5+B×0.273)<DY+B×0.136 is satisfied. The ultrasonic sensor device according to claim 1 .

4. The curve that is symmetrical with respect to the X-axis is any one of a parabola, a quadratic curve, and a circle. The ultrasonic sensor device according to claim 1 .

5. An ultrasonic sensor device comprising: an ultrasonic sensor device according to any one of claims 1 to 4; vehicle.

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