Ultrasonic Transducers

Abstract

To provide an ultrasonic transducer in which contact of members connecting an electrode of a piezoelectric element and a terminal of a case can be prevented.SOLUTION: An ultrasonic transducer 10 comprises: a piezoelectric element 21 including a first electrode 25 on a first surface 23 and a second electrode 26 on a second surface 24; a tabular member 22 electrically connected to the second electrode 26; a first terminal portion 44 and a second terminal portion 45 provided in a case 40; a first connection member 50 electrically connecting the first electrode 25 and the first terminal portion 44; and a second connection member 60 electrically connecting the second electrode 26 and the second terminal portion 45. The tabular member 22 includes a contact point portion 27 protruding to outside from an outer edge of the second surface 24 and opposing the second terminal portion 45. The first connection member 50 can be elastically contacted to the first electrode 25 and the first terminal portion 44. The second connection member 60 is formed in a cylindrical shape enclosing an outer peripheral side of the first connection member 50 while separating from the first connection member 50 and can come in elastic contact with the contact portion 27 and the second terminal portion 45.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an ultrasonic transducer. [Background technology]

[0002] Conventionally, ultrasonic transducers used for transmitting and receiving ultrasonic waves are known. For example, the ultrasonic transducer described in the following Patent Document 1 electrically connects the electrodes of the piezoelectric element and the terminals built into the case by a connector. The connector is an elastic member having electrical conductivity. This can reduce the number of assembly steps compared to the case where the electrodes of the piezoelectric element and the terminals of the case are connected by soldering lead wires, and can also prevent defects caused by solder peeling and the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 4-187000 Summary of the Invention [Problem to be solved by the invention]

[0004] In an ultrasonic transducer having the above-described configuration, if the members connecting the electrodes of the piezoelectric elements and the terminals of the case are disposed in close proximity to each other, there is a risk that the connecting members may come into contact with each other.

[0005] The present invention was developed based on the above-mentioned circumstances, and its object is to provide an ultrasonic transducer that can prevent contact between the components connecting the electrodes of the piezoelectric element and the terminals of the case. [Means for solving the problem]

[0006] The ultrasonic transducer of the present invention comprises a piezoelectric element having a first electrode on a first surface formed on one side in the thickness direction and a second electrode on a second surface formed on the other side in the thickness direction, a plate-shaped member joined to the second surface and electrically connected to the second electrode, a case for housing the piezoelectric element and the plate-shaped member, a first terminal portion and a second terminal portion provided on the side of the case facing the first surface, a first connecting member electrically connecting the first electrode and the first terminal portion, and a second connecting member electrically connecting the second electrode and the second terminal portion, wherein the plate-shaped member has a contact portion that protrudes outward from the outer edge of the second surface and faces the second terminal portion, the first connecting member is capable of elastically contacting the first electrode and the first terminal portion in the opposing direction of the first electrode and the first terminal portion, and the second connecting member is tubular and surrounds the outer periphery of the first connecting member while being separated from the first connecting member, and is capable of elastically contacting the contact portion and the second terminal portion in the opposing direction of the contact portion and the second terminal portion. Effect of the Invention

[0007] According to the present invention, the first and second electrodes of the piezoelectric element and the first and second terminals provided on the case can be connected without soldering lead wires. Furthermore, since the first and second connecting members are arranged apart from each other, contact between the first and second connecting members can be prevented. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view showing an ultrasonic transducer according to a first embodiment; [Diagram 2] 1 is an exploded cross-sectional view of an ultrasonic transducer showing a vibrator, a resonator, a first connecting member, and a second connecting member; [Diagram 3] FIG. 3 is a diagram showing the positional relationship between the first connection member and the first surface of the piezoelectric element, as viewed from the position AA in FIG. 2; [Figure 4] FIG. 3 is a diagram showing the positional relationship between the second connection member and the contact portion of the plate-like member, as viewed from the position BB in FIG. 2 . [Diagram 5]FIG. 11 is a partially enlarged cross-sectional view showing the vicinity of an end portion of a first connecting member of an ultrasonic transducer according to a second embodiment; [Figure 6] FIG. 11 is a partially enlarged cross-sectional view showing an end portion and its vicinity of a first connecting member of an ultrasonic transducer according to a third embodiment; [Figure 7] FIG. 11 is a cross-sectional view showing an ultrasonic transducer according to a fourth embodiment. [Figure 8] FIG. 13 is a cross-sectional view showing an ultrasonic transducer according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A preferred embodiment of the present invention is described below.

[0010] In the ultrasonic transducer of the present invention, the first connecting member may be cylindrical and in contact with a region of the first surface that is outside the midpoint between the center point of the first surface and the outer edge of the first surface. The center of the piezoelectric element is a portion that is an antinode of vibration or a portion near the antinode of vibration. According to this configuration, the first connecting member contacts the outer region of the first surface while avoiding the portion that is the antinode of vibration. Therefore, it is possible to prevent the first connecting member from interfering with the vibration of the piezoelectric element, and thus ultrasonic waves can be transmitted and received efficiently.

[0011] In the ultrasonic transducer of the present invention, the second connection member may be in contact with a region of the contact portion that is on the inside of a midpoint between an outer edge of the second surface and an outer edge of the contact portion. The outer edge of the plate-shaped member is a portion that is an antinode of vibration or a portion near the antinode of vibration. According to this configuration, the second connection member is in contact with an inner region of the plate-shaped member, avoiding the portion that is an antinode of vibration. Therefore, it is possible to prevent the second connection member from interfering with the vibration of the piezoelectric element, and thus to efficiently transmit and receive ultrasonic waves.

[0012] In the ultrasonic transducer of the present invention, the first connection member may be a coil spring formed by winding a conductive wire in a spiral shape to form a plurality of annular portions aligned in the axial direction, and the end of the wire that contacts the first electrode may extend at an angle closer to perpendicular to the axial direction than the other annular portions in a natural state before contacting the first electrode. With this configuration, the end of the first connection member that contacts the first electrode is aligned with the first electrode, so that the tip of the first connection member can be prevented from making point contact with the first electrode.

[0013] In the ultrasonic transducer of the present invention, the first connection member may be a coil spring formed by winding a conductive wire in a spiral shape to form a plurality of annular portions aligned in the axial direction, and an end face of the wire that contacts the first electrode may be ground perpendicular to the axial direction in a natural state before contacting the first electrode. With this configuration, the end face formed on the end of the first connection member that contacts the first electrode is aligned with the first electrode, so that the tip of the first connection member can be prevented from making point contact with the first electrode.

[0014] <Example 1> An embodiment of the present invention will be described in detail below with reference to Figs. 1 to 4. The ultrasonic transducer 10 in this embodiment is used in a medical or industrial ultrasonic device. The ultrasonic transducer 10 is electrically connected to a control unit (not shown) and transmits and receives ultrasonic waves.

[0015] The ultrasonic transducer 10 includes a vibrator 20, a resonator 30, a case 40, a first connecting member 50, and a second connecting member 60. The ultrasonic transducer 10 is an open type, and the case 40 has a mesh-like opening 41 formed therein.

[0016] The vibrator 20 includes a piezoelectric element 21 and a plate-like member 22. The piezoelectric element 21 is made of PZT (lead zirconate titanate), KNN (potassium sodium niobate), or the like, and is in the form of a substantially circular plate. A first surface 23 is formed on one side of the thickness direction of the piezoelectric element 21 (lower side in FIG. 1), and a second surface 24 is formed on the other side of the thickness direction of the piezoelectric element 21 (upper side in FIG. 1). The first surface 23 and the second surface 24 are concentric circular shapes. The first surface 23 and the second surface 24 are parallel to each other. The area of ​​the first surface 23 and the area of ​​the second surface 24 are equal.

[0017] The piezoelectric element 21 has a first electrode 25 and a second electrode 26. The first electrode 25 and the second electrode 26 are formed by vapor deposition, plating, sputtering, baking, or the like of gold, silver, copper, tin, or the like. The first electrode 25 and the second electrode 26 are circular. The first electrode 25 is formed on the entire first surface 23 of the piezoelectric element 21. The second electrode 26 is formed on the entire second surface 24 of the piezoelectric element 21.

[0018] The plate-shaped member 22 is a vibration plate made of a metal plate. The plate-shaped member 22 is disposed on the second surface 24 of the piezoelectric element 21. The plate-shaped member 22 is attached to the second surface 24 with an adhesive 43. The plate-shaped member 22 is electrically connected to the second electrode 26. The plate-shaped member 22 has a circular shape in a plan view (see FIG. 4). The plate-shaped member 22 is disposed coaxially with the piezoelectric element 21. The outer diameter of the plate-shaped member 22 is larger than the outer diameter of the piezoelectric element 21.

[0019] As shown in Fig. 2, the plate-shaped member 22 has a contact portion 27 that protrudes outward from the outer edge 24S of the second surface 24. The contact portion 27 forms a continuous ring shape around the entire circumference of the plate-shaped member 22 (see Fig. 4). The width dimension 27W of the contact portion 27 is constant around the entire circumference. The width dimension 27W of the contact portion 27 is the radial dimension of the plate-shaped member 22 and is the shortest distance between the outer edge 24S of the second surface 24 and the outer edge 27S of the contact portion 27. The outer edge 27S of the contact portion 27 is the outer peripheral edge of the surface of the plate-shaped member 22 that contacts the second surface 24.

[0020] The resonator 30 is made of metal and has a conical shape. The resonator 30 is fixed to the center of the upper surface of the plate-like member 22 by an adhesive (not shown). The resonator 30 efficiently radiates ultrasonic waves generated by vibration into the air, and effectively concentrates the ultrasonic waves from the air on the central portion of the vibrator 20.

[0021] The case 40 is made of synthetic resin, and houses the vibrator 20, the resonator 30, the first connecting member 50, and the second connecting member 60 therein, as shown in Fig. 1. An opening 41 is provided on the upper surface of the case 40. A base portion 42 is provided on the lower side of the case 40 (the side facing the first surface 23). The lower surface of the case 40 is closed by the base portion 42.

[0022] The vibrator 20 is elastically fixed to the base portion 42 by an adhesive 43. The adhesive 43 is made of low hardness silicone or the like and has elasticity. The adhesive 43 floats the vibrator 20 above the base portion 42. The adhesive 43 supports the outer edge of the piezoelectric element 21.

[0023] The base portion 42 is provided with a first terminal portion 44 and a second terminal portion 45. The first terminal portion 44 and the second terminal portion 45 are electrical signal input / output terminals. The first terminal portion 44 and the second terminal portion 45 are embedded in the base portion 42.

[0024] The first terminal portion 44 is a metal pin. The first terminal portion 44 is disposed in the center of the base portion 42. The first terminal portion 44 is rod-shaped and long in the vertical direction. The first terminal portion 44 is disposed on an extension of the central axis L of the piezoelectric element 21. The upper surface of the first terminal portion 44 is exposed on the upper surface of the base portion 42. The upper surface of the first terminal portion 44 is a contact surface (referred to as a first contact surface 46) with the first connecting member 50. The first contact surface 46 faces the first electrode 25 in the vertical direction. The first contact surface 46 is located directly below the center of the piezoelectric element 21. The lower end portion of the first terminal portion 44 protrudes outside the case 40.

[0025] The second terminal portion 45 is a metal plate. A plate surface of the second terminal portion 45 is exposed on the upper surface of the base portion 42. The exposed plate surface of the second terminal portion 45 constitutes a contact surface (referred to as a second contact surface 47) with the second connection member 60. The second contact surface 47 faces the contact portion 27 in the up-down direction. A part of the second terminal portion 45 protrudes to the outside of the case 40.

[0026] The first connecting member 50 electrically connects the first electrode 25 of the piezoelectric element 21 and the first terminal portion 44 provided on the case 40. The second connecting member 60 electrically connects the contact portion 27 of the plate-shaped member 22 and the second terminal portion 45 provided on the case 40, thereby electrically connecting the second electrode 26 of the piezoelectric element 21 and the second terminal portion 45.

[0027] As shown in FIG. 2, the first connecting member 50 and the second connecting member 60 are compression coil springs formed by spirally winding conductive wires 53, 63 such as metallic wires. The first connecting member 50 and the second connecting member 60 have elasticity in the axial direction. The first connecting member 50 and the second connecting member 60 are both cylindrical. The diameters of the first connecting member 50 and the second connecting member 60 are constant in the axial direction. The length (axial dimension) of the first connecting member 50 in the natural state is smaller than the length (axial dimension) of the second connecting member 60 in the natural state. The natural state of the first connecting member 50 is an unloaded state before the first connecting member 50 contacts the first electrode 25 and the first terminal portion 44, and the natural state of the second connecting member 60 is an unloaded state before the second connecting member 60 contacts the contact portion 27 and the second terminal portion 45.

[0028] As shown in Fig. 2, the first connection member 50 and the second connection member 60 each have a plurality of annular portions 54, 64 arranged in the axial direction. The plurality of annular portions 54, 64 are arranged in the axial direction at a generally constant pitch in a natural state. Each of the annular portions 54, 64 has a circular shape when viewed in the axial direction (see Figs. 3 and 4).

[0029] 1, the first connecting member 50 is arranged in an orientation in which it has elasticity in the opposing direction between the first electrode 25 and the first terminal portion 44. The first connecting member 50 is arranged inside the adhesive 43. The central axis of the first connecting member 50 is on an extension of the central axis L of the piezoelectric element 21 in a state in which the first connecting member 50 is arranged between the first electrode 25 and the first terminal portion 44.

[0030] The outer diameter of the first connecting member 50 is smaller than the outer diameter of the piezoelectric element 21 and the outer diameter of the first contact surface 46 of the first terminal portion 44. An upper end (referred to as a vibrating body side contact portion 51) of the wire 53 of the first connecting member 50 is in elastic contact with the first electrode 25. A lower end (referred to as a terminal side contact portion 52) of the wire 53 of the first connecting member 50 is in elastic contact with the first terminal portion 44.

[0031] As shown in Fig. 3, the vibrator side contact portion 51 of the first connecting member 50 is in contact with an outer region R2 of the first surface 23 of the piezoelectric element 21. The position of the vibrator side contact portion 51 is a position overlapping with the annular portion 54 in the axial direction in Fig. 3. The outer region R2 is outside of the midpoint 23C between the center point 23P of the first surface 23 and the outer edge 23S of the first surface 23. The center point 23P of the first surface 23 is the intersection point of the central axis L of the piezoelectric element 21 and the first surface 23. The first connecting member 50 is in contact with the vibrator 20, avoiding the portions that become the antinodes of vibration.

[0032] As shown in FIG. 1, the second connecting member 60 is disposed in an orientation having elasticity in the opposing direction of the contact portion 27 and the second terminal portion 45. The second connecting member 60 is disposed at a position away from the first connecting member 50 and surrounds the outer periphery of the first connecting member 50. The inner diameter of the second connecting member 60 is larger than the outer diameter of the piezoelectric element 21 and smaller than the outer diameter of the plate-like member 22. An upper end portion (referred to as a vibrator-side contact portion 61) of the wire 63 of the second connecting member 60 is in elastic contact with the contact portion 27 of the plate-like member 22. A lower end portion (referred to as a terminal-side contact portion 62) of the wire 63 of the second connecting member 60 is in elastic contact with the second terminal portion 45.

[0033] The vibrator side contact portion 61 of the second connecting member 60 is in contact with an inner region R1 of the contact portion 27 (see FIG. 4). The position of the vibrator side contact portion 61 is a position overlapping with the annular portion 64 in the axial direction in FIG. 4. The inner region R1 is on the inside of a midpoint 27C between the outer edge 24S of the second surface 24 and the outer edge 27S of the contact portion 27. The vibrator side contact portion 61 is in contact with a center side region R3 of the inner region R1. The center side region R3 is on the inside of a midpoint 28C between the outer edge 24S of the second surface 24 and the midpoint 27C of the contact portion 27. The second connecting member 60 is in contact with the vicinity of a portion that becomes a vibration node of the vibrator 20.

[0034] The first connecting member 50 and the second connecting member 60 are disposed approximately coaxially. This allows the distance between the first connecting member 50 and the second connecting member 60 to be uniform over the entire circumference. If the distance between the first connecting member 50 and the second connecting member 60 is non-uniform, the first connecting member 50 and the second connecting member 60 are likely to come into contact with each other in areas where the distance between the first connecting member 50 and the second connecting member 60 is small. However, since the distance between the first connecting member 50 and the second connecting member 60 is uniform over the entire circumference, it is possible to make it difficult for the first connecting member 50 and the second connecting member 60 to come into contact with each other.

[0035] According to the embodiment configured as above, the following effects are achieved. The ultrasonic transducer 10 includes a piezoelectric element 21, a plate-shaped member 22, a first terminal portion 44, a second terminal portion 45, a first connecting member 50, and a second connecting member 60. The piezoelectric element 21 has a first electrode 25 on a first surface 23 formed on the lower side (one side in the thickness direction), and has a second electrode 26 on a second surface 24 formed on the upper side (the other side in the thickness direction). The plate-shaped member 22 is disposed along the second surface 24 and protrudes outward from an outer edge 24S of the second surface 24. The plate-shaped member 22 is electrically connected to the second electrode 26. The first terminal portion 44 and the second terminal portion 45 are provided on the lower side (the side facing the first surface 23) of the case 40 that houses the piezoelectric element 21 and the plate-shaped member 22. The first connecting member 50 electrically connects the first electrode 25 and the first terminal portion 44. The second connection member 60 electrically connects the second electrode 26 and the second terminal portion 45. The plate-like member 22 has a contact portion 27 facing the second terminal portion 45. The first connection member 50 has elasticity in the opposing direction of the first electrode 25 and the first terminal portion 44, and can elastically contact the first electrode 25 and the first terminal portion 44. The second connection member 60 is tubular and surrounds the outer periphery of the first connection member 50 in a state separated from the first connection member 50. The second connection member 60 has elasticity in the opposing direction of the contact portion 27 and the second terminal portion 45, and can elastically contact the contact portion 27 and the second terminal portion 45.

[0036] According to this configuration, the first electrode 25 and the second electrode 26 of the piezoelectric element 21 can be connected to the first terminal portion 44 and the second terminal portion 45 provided on the case 40 without soldering lead wires. In addition, since the first connecting member 50 and the second connecting member 60 are arranged apart from each other, contact between the first connecting member 50 and the second connecting member 60 can be prevented.

[0037] Moreover, the first connecting member 50 is cylindrical and contacts the first surface 23 with an area R2 outside the midpoint 23C between the center point 23P of the first surface 23 and the outer edge 23S of the first surface 23. Here, the center of the piezoelectric element 21 is the antinode of vibration or a portion near the antinode of vibration. According to the ultrasonic transducer 10 of this embodiment, the first connecting member 50 contacts the outer area R2 of the first surface 23, avoiding the portion that becomes the antinode of vibration. Therefore, it is possible to prevent the first connecting member 50 from interfering with the vibration of the piezoelectric element 21, and thus it is possible to transmit and receive ultrasonic waves efficiently.

[0038] Moreover, the second connecting member 60 is in contact with an area R1 of the contact portion 27 that is on the inside of a midpoint 27C between the outer edge 24S of the second surface 24 and the outer edge 27S of the contact portion 27. Here, the outer edge portion of the plate-like member 22 is a portion that is an antinode of vibration or a portion near the antinode of vibration. According to the ultrasonic transducer 10 of this embodiment, the second connecting member 60 is in contact with the inner area R1 of the plate-like member 22, avoiding the portion that is an antinode of vibration. Therefore, it is possible to prevent the second connecting member 60 from interfering with the vibration of the piezoelectric element 21, and thus it is possible to transmit and receive ultrasonic waves efficiently.

[0039] <Example 2> Next, an ultrasonic transducer 10 according to a second embodiment of the present invention will be described with reference to Fig. 5. The ultrasonic transducer 10 of this embodiment differs from the first embodiment in that the vibrator side contact portion 100 of the first connecting member 50 extends at an angle closer to perpendicular to the axial direction of the first connecting member 50 than the other annular portions 54. Note that the same components as those in the first embodiment are given the same reference numerals and redundant explanations will be omitted.

[0040] The ultrasonic transducer 10 according to this embodiment includes, similarly to the first embodiment, a vibrator 20, a resonator 30, a case 40, a first connecting member 50, and a second connecting member 60. As in the first embodiment, the first connecting member 50 is a compression coil spring formed by winding a conductive wire 53 in a spiral shape so that a plurality of annular portions 54 are aligned in the axial direction.

[0041] 5 shows an enlarged view of a portion of a cross section of the first connecting member 50 divided in two along the axial direction. In a natural state, the extension direction 101 of the vibrating body side contact portion 100 of the first connecting member 50 is different from the extension direction 102 of the other annular portions 54. The extension direction 101 of the vibrating body side contact portion 100 of the first connecting member 50 is closer to a right angle to the axial direction than the extension direction 102 of the other annular portions 54. The axial distance between the vibrating body side contact portion 100 and the adjacent annular portion 54 narrows toward the tip of the vibrating body side contact portion 100. The tip of the vibrating body side contact portion 100 is in contact with or close to the adjacent annular portion 54.

[0042] As described above, in this embodiment, as in the first embodiment, the first connection member 50 and the second connection member 60 are disposed apart from each other, so that contact between the first connection member 50 and the second connection member 60 can be prevented. In addition, the vibrator side contact portion 100 of the first connection member 50 is aligned with the first electrode 25, so that the tip of the first connection member 50 can be prevented from making point contact with the first electrode 25. Here, when the tip of the first connection member makes point contact with the first electrode 25, the contact pressure of the first connection member is likely to be non-uniform. This may cause the contact position of the first connection member to be easily shifted and become unstable. In addition, since the contact pressure is likely to be concentrated at one point on the first electrode 25, there is a risk that the first electrode 25 may peel off. However, the first connection member 50 of this embodiment makes surface contact with the first electrode 25. Therefore, the contact pressure between the first electrode 25 and the first connection member 50 is likely to be uniform, the contact position of the first connection member 50 is stable, and peeling of the first electrode 25 can be prevented.

[0043] <Example 3> Next, an ultrasonic transducer 10 according to a third embodiment of the present invention will be described with reference to Fig. 6. The ultrasonic transducer 10 of this embodiment differs from the first embodiment in that an end face 111 that is ground perpendicularly to the axial direction of the first connecting member 50 is formed on the vibrating body side contact portion 110 of the first connecting member 50. Note that the same components as those in the first embodiment are given the same reference numerals and redundant explanations will be omitted.

[0044] The ultrasonic transducer 10 according to this embodiment, like the first embodiment, includes a vibrator 20, a resonator 30, a case 40, a first connecting member 50, and a second connecting member 60. Like the first embodiment, the first connecting member 50 is a compression coil spring formed by spirally winding a conductive wire 53 so that a plurality of annular portions 54 are aligned in the axial direction.

[0045] 6 shows an enlarged view of a portion of a cross section obtained by dividing the first connecting member 50 into two along the axial direction. In a natural state, an extension direction 112 of the vibrating body side contact portion 110 of the first connecting member 50 is parallel to an extension direction 113 of the other annular portion 54. The end face 111 is formed by grinding a portion of the vibrating body side contact portion 110 above the end face 111. The end face 111 is continuous to the tip of the vibrating body side contact portion 110.

[0046] As described above, in this embodiment, similarly to the first embodiment, the first connection member 50 and the second connection member 60 are disposed apart from each other, and therefore it is possible to prevent contact between the first connection member 50 and the second connection member 60. In addition, the end face 111 formed on the vibrator side contact portion 100 of the first connection member 50 is aligned with the first electrode 25, and therefore it is possible to prevent the tip of the first connection member 50 from making point contact with the first electrode 25. Therefore, similarly to the second embodiment, the contact pressure between the first electrode 25 and the first connection member 50 tends to be uniform, the contact position of the first connection member 50 is stable, and peeling of the first electrode 25 can be prevented.

[0047] <Example 4> Next, an ultrasonic transducer 120 according to a fourth embodiment of the present invention will be described with reference to Fig. 7. The ultrasonic transducer 120 of this embodiment differs from the first embodiment in that a positioning portion 121 for positioning the first connecting member 50 and the second connecting member 60 is provided on the case 40. Note that the same components as those in the first embodiment are denoted by the same reference numerals and redundant description will be omitted.

[0048] The ultrasonic transducer 120 according to this embodiment includes, similarly to the first embodiment, a vibrator 20, a resonator 30, a case 40, a first connecting member 50, and a second connecting member 60. The positioning portion 121 is provided on the base portion 42. The positioning portion 121 protrudes upward from the upper surface of the base portion 42. The positioning portion 121 includes a first positioning portion 122 and a second positioning portion 123. The first positioning portion 122 is provided on the inside of the second positioning portion 123.

[0049] The first positioning portion 122 is disposed on the outside of the first contact surface 46. The inside of the first positioning portion 122 is a mounting portion 125 of the first connecting member 50. The adhesive 43 is disposed on an upper surface of the first positioning portion 122. The second positioning portion 123 is disposed on the outside of the second connecting member 60. Between the first positioning portion 122 and the second positioning portion 123 is a mounting portion 124 of the second connecting member 60.

[0050] As described above, in this embodiment, similarly to the first embodiment, the first connecting member 50 and the second connecting member 60 are disposed apart from each other, so that contact between the first connecting member 50 and the second connecting member 60 can be prevented. In addition, the first connecting member 50 and the second connecting member 60 are held at positions apart from each other by the positioning portion 121. Therefore, contact between the first connecting member 50 and the second connecting member 60 can be reliably prevented.

[0051] <Example 5> Next, an ultrasonic transducer 130 according to a fifth embodiment of the present invention will be described with reference to Fig. 8. The ultrasonic transducer 130 of this embodiment is different from the first embodiment in that it is a sealed type. Note that the same components as those of the first embodiment are given the same reference numerals and the duplicated description will be omitted.

[0052] The ultrasonic transducer 130 according to this embodiment includes a piezoelectric element 21, a plate-shaped member 22, a case 131, a first connecting member 50, and a second connecting member 60. The case 131 is made of synthetic resin and houses the piezoelectric element 21, the plate-shaped member 22, the first connecting member 50, and the second connecting member 60 inside. No opening is provided in the case 131, and the inside of the case 131 is sealed. The case 131 is provided with a first terminal portion 44 and a second terminal portion 45, similar to the first embodiment. The first connecting member 50 electrically connects the first electrode 25 of the piezoelectric element 21 and the first terminal portion 44 of the case 131, similar to the first embodiment. The second connecting member 60 electrically connects the contact portion 27 of the plate-shaped member 22 and the second terminal portion 45 of the case 131, similar to the first embodiment.

[0053] As described above, in this embodiment, similarly to the first embodiment, the first connecting member 50 and the second connecting member 60 are disposed apart from each other, so that it is possible to prevent contact between the first connecting member 50 and the second connecting member 60. In addition, since the ultrasonic transducer 130 is of a sealed type, it is possible to prevent water from entering the inside of the case 131.

[0054] <Other Examples> The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments are also included within the technical scope of the present invention. (1) In the above embodiment, the first connecting member 50 and the second connecting member 60 are compression coil springs. However, the first connecting member and the second connecting member are not limited to this, and may be a conductive sponge, a conductive rubber tube, a conductive plastic, etc. (2) In the above embodiment, the first electrode 25 and the second electrode 26 of the piezoelectric element 21 are respectively formed on the entire first surface 23 and the second surface 24 of the piezoelectric element 21. However, the present invention is not limited to this, and the first electrode and the second electrode may be formed partially on the first surface and the second surface of the piezoelectric element. (3) In the above embodiment, the shapes and arrangements of the first terminal portion 44 and the second terminal portion 45 are illustrated as examples. However, the shapes and arrangements of the first terminal portion and the second terminal portion 45 are not limited to these and may be changed. (4) In the above embodiment, the first connection member 50 is in contact with the outer region R2 of the first surface 23. However, the present invention is not limited to this, and the first connection member may be in contact with an inner region of the first surface. (5) In the above embodiment, the second connection member 60 is in contact with the inner region R1 of the contact portion 27. However, the present invention is not limited to this, and the second connection member may be in contact with an outer region of the contact portion. (6) In the above-mentioned Examples 2 and 3, the configuration of the vibrating body side contact portion 110, 110 of the first connecting member 50 has been described. This configuration may be applied to the vibrating body side contact portion of the second connecting member. By applying this configuration to the vibrating body side contact portion of the second connecting member, it is possible to prevent the tip of the second connecting member from making point contact with the contact portion of the plate-shaped member. [Explanation of symbols]

[0055] R1: The inner area of ​​the contact R2: The outer area of ​​the first surface 10, 120, 130...Ultrasonic transducer 21...Piezoelectric element 22...Plate-shaped member 23…Front page 23C... Midpoint of the first face (midpoint between the center point of the first face and the outer edge) 23P…Center point of the first surface 23S…Outer edge of the first surface 24…Second side 24S…Outer edge of second surface 25...first electrode 26…Second electrode 27…Contact part 27C...Midpoint of contact part (midpoint between the outer edge of the second surface and the outer edge of the contact part) 27S…Outer edge of contact 40,131…cases 44...First terminal part 45...Second terminal section 50...First connecting member 51, 100, 110...Vibrator side contact portion (end portion contacting the first electrode) 53...Wire rod 54…Annular section 60...Second connecting member 111...End face (end face ground perpendicular to the axial direction)

Claims

1. a piezoelectric element having a first electrode on a first surface formed on one side in a thickness direction and a second electrode on a second surface formed on the other side in the thickness direction; a plate-like member joined to the second surface and electrically connected to the second electrode; a case that houses the piezoelectric element and the plate-like member; a first terminal portion and a second terminal portion provided on a side of the case facing the first surface; a first connection member that electrically connects the first electrode and the first terminal portion; a second connection member electrically connecting the second electrode and the second terminal portion, the plate-like member has a contact portion that protrudes outward from an outer edge of the second surface and faces the second terminal portion, the first connection member is capable of elastically coming into contact with the first electrode and the first terminal portion in an opposing direction of the first electrode and the first terminal portion, The second connecting member is a cylindrical member that surrounds the outer periphery of the first connecting member while separated from the first connecting member, and is an ultrasonic transducer that is capable of elastically contacting the contact portion and the second terminal portion in the opposing direction between the contact portion and the second terminal portion.

2. The ultrasonic transducer of claim 1 , wherein the first connecting member is cylindrical and contacts an area of ​​the first surface that is outside the midpoint between a center point of the first surface and an outer edge of the first surface.

3. The ultrasonic transducer according to claim 1 or 2, wherein the second connection member is in contact with a region of the contact portion that is on the inside of a midpoint between an outer edge of the second surface and an outer edge of the contact portion.

4. the first connection member is a coil spring formed by winding a conductive wire in a spiral shape so that a plurality of annular portions are arranged in the axial direction, An ultrasonic transducer as described in any one of claims 1 to 3, wherein the end of the wire that contacts the first electrode extends at an angle closer to perpendicular to the axial direction than the other annular portions in its natural state before contacting the first electrode.

5. the first connection member is a coil spring formed by winding a conductive wire in a spiral shape so that a plurality of annular portions are arranged in the axial direction, An ultrasonic transducer as described in any one of claims 1 to 3, wherein an end face that is ground perpendicular to the axial direction is formed on the end of the wire that contacts the first electrode in its natural state before contacting the first electrode.

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