WO2013047544A1 - 超音波センサ - Google Patents
超音波センサ Download PDFInfo
- Publication number
- WO2013047544A1 WO2013047544A1 PCT/JP2012/074620 JP2012074620W WO2013047544A1 WO 2013047544 A1 WO2013047544 A1 WO 2013047544A1 JP 2012074620 W JP2012074620 W JP 2012074620W WO 2013047544 A1 WO2013047544 A1 WO 2013047544A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- electrode
- piezoelectric element
- case
- ultrasonic sensor
- vibration
- Prior art date
Links
- 239000000758 substrate Substances 0.000 claims abstract description 50
- 230000035945 sensitivity Effects 0.000 abstract description 14
- 230000010355 oscillation Effects 0.000 abstract 3
- 230000002349 favourable effect Effects 0.000 abstract 1
- 239000000463 material Substances 0.000 description 68
- 238000013016 damping Methods 0.000 description 14
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 8
- CNQCVBJFEGMYDW-UHFFFAOYSA-N lawrencium atom Chemical compound [Lr] CNQCVBJFEGMYDW-UHFFFAOYSA-N 0.000 description 7
- 239000011358 absorbing material Substances 0.000 description 6
- 230000008878 coupling Effects 0.000 description 5
- 238000010168 coupling process Methods 0.000 description 5
- 238000005859 coupling reaction Methods 0.000 description 5
- 239000012779 reinforcing material Substances 0.000 description 5
- 239000000853 adhesive Substances 0.000 description 3
- 230000001070 adhesive effect Effects 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000003014 reinforcing effect Effects 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- 229920002803 thermoplastic polyurethane Polymers 0.000 description 3
- 239000000919 ceramic Substances 0.000 description 2
- 239000004020 conductor Substances 0.000 description 2
- 238000005304 joining Methods 0.000 description 2
- 229920001707 polybutylene terephthalate Polymers 0.000 description 2
- 230000002787 reinforcement Effects 0.000 description 2
- 229920002050 silicone resin Polymers 0.000 description 2
- 229920002379 silicone rubber Polymers 0.000 description 2
- 239000004945 silicone rubber Substances 0.000 description 2
- 229910000679 solder Inorganic materials 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000003064 anti-oxidating effect Effects 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005242 forging Methods 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 description 1
- 229910052451 lead zirconate titanate Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- -1 polybutylene terephthalate Polymers 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 239000011359 shock absorbing material Substances 0.000 description 1
- 238000005476 soldering Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
- B06B1/0644—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using a single piezoelectric element
- B06B1/0655—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using a single piezoelectric element of cylindrical shape
Definitions
- the present invention relates to an ultrasonic sensor having a structure in which a piezoelectric element is joined to a case, for example, an ultrasonic sensor used for a corner sonar, a back sonar, etc. of an automobile.
- the ultrasonic sensor detects an obstacle or target by intermittently transmitting an ultrasonic pulse signal and receiving a reflected wave reflected after the transmitted ultrasonic pulse signal reaches the obstacle or target.
- Ultrasonic sensors are used for back sonars, corner sonars of automobiles, and parking spot sensors for detecting distances from obstacles such as side walls in parallel parking.
- FIG. 6A is a cross-sectional view showing a configuration example of a conventional ultrasonic sensor.
- the ultrasonic sensor 101 includes a case 102, a piezoelectric element 103, a damping material 104, a substrate 105, a foamable resin 106, pin terminals 107A and 107B, and lead wires 108A and 108B.
- the case 102 has a bottomed cylindrical shape and is made of a conductive material such as metal.
- the piezoelectric element 103 is joined to the inner bottom surface of the case 102 with a conductive adhesive or the like.
- FIG. 6B is a perspective view illustrating a configuration example of the piezoelectric element 103.
- the piezoelectric element 103 is made of piezoelectric ceramics, and includes a disk-shaped piezoelectric substrate 103C and electrodes 103A and 103B provided on main surfaces of the piezoelectric substrate 103C facing each other.
- the piezoelectric element 103 is bonded to the case 102 so that the electrode 103A contacts the inner bottom surface of the opening of the case 102.
- the damping material 104 is provided so as to close the opening of the case 102.
- the substrate 105 is provided on the damping material 104.
- the substrate 105 and the damping material 104 are provided with through holes.
- the foamable resin 106 is injected from one of the through holes into the opening of the case 102 and filled in the case 102 and the through holes.
- Each of the pin terminals 107A and 107B has a straight bar shape, and is inserted into the opening of the case 102 through one of the through holes.
- the lead wire 108 ⁇ / b> A is joined to the tip of the pin terminal 107 ⁇ / b> A and the case 102 by solder in the opening of the case 102, and electrically connects the pin terminal 107 ⁇ / b> A and the case 102. For this reason, the pin terminal 107A is electrically connected to the electrode 103A via the lead wire 108A and the case 102.
- the lead wire 108B is joined to the tip of the pin terminal 107B and the electrode 103B of the piezoelectric element 103 by soldering, and the tip of the pin terminal 107B and the electrode 103B of the piezoelectric element 103 are electrically connected. Connected.
- the piezoelectric element is joined to the inner bottom surface of the case opening so that the center position of the piezoelectric element coincides with the center of the inner bottom surface of the case opening.
- the vibration efficiency and the overall sensitivity of the piezoelectric element in the ultrasonic sensor may decrease.
- a lead wire is directly connected to one electrode of the piezoelectric element, and a lead wire is indirectly connected to the other electrode via a case. For this reason, it is necessary to perform wiring work twice between the piezoelectric element and the case at the time of manufacture, and the work is complicated.
- an object of the present invention is to realize high bonding accuracy between the piezoelectric element and the case while connecting the wiring member to the electrode of the piezoelectric element without going through the case, and to improve the vibration efficiency and overall sensitivity of the piezoelectric element. It is to realize an ultrasonic sensor having a configuration that can be obtained.
- the ultrasonic sensor of the present invention includes a case and a piezoelectric element.
- the case has a bottom surface portion that is a vibration region and has a bottomed cylindrical shape.
- the piezoelectric element has a piezoelectric substrate, a first electrode, a second electrode, and a third electrode.
- the piezoelectric substrate has a first surface and a second surface facing the first surface.
- the first electrode is provided on the first surface.
- the second electrode is provided on a part of the second surface.
- the third electrode is provided apart from the second electrode on a part of the second surface, and is connected to the first electrode.
- the first electrode is joined to the bottom surface, and the center of the piezoelectric element is arranged at a position different from the center of the vibration region in plan view.
- the area of the region where the second electrode is provided on the second surface of the piezoelectric substrate is different from the area of the region where the third electrode is provided.
- the second electrode and the third electrode are provided asymmetrically in plan view of the piezoelectric element.
- the vibration region has a planar shape having a longitudinal direction and a short direction when the bottom surface portion is viewed in plan, and the second electrode and the third electrode are arranged in the short direction. It is preferable.
- the piezoelectric element is arranged at a position where the center of the piezoelectric element is different from the center of the vibration region in plan view of the bottom surface portion, the vibration efficiency and the overall sensitivity of the piezoelectric element in the ultrasonic sensor are improved. And the characteristics can be improved.
- the second electrode and the third electrode are provided on the second surface of the piezoelectric substrate, a wiring portion such as a flexible substrate or a lead wire can be directly connected without passing through the case. As a result, there are fewer restrictions on the materials that can be used. Furthermore, the connection between the second electrode and the third electrode and the wiring portion can be performed even after the piezoelectric element is bonded to the case, and the bonding accuracy between the piezoelectric element and the case can be increased.
- FIG. 1A is a cross-sectional view of the ultrasonic sensor 1 according to the first embodiment of the present invention.
- FIG. 1B is a plan view of the ultrasonic sensor 1. Note that FIG. 1A shows a cross section at a position indicated by AA ′ in FIG. FIG. 1B shows the back surface of the ultrasonic sensor 1.
- the ultrasonic sensor 1 includes a case 2, a piezoelectric element 3, a sound absorbing material 4, a reinforcing material 5, a support material 6, a buffer material 7, a vibration damping material 8, a flexible substrate 9, and a terminal holding material 10. And pin terminals 11A and 11B.
- the case 2 has a bottomed cylindrical shape in which the lower end surface (front surface) in FIG. 1 (A) is closed and the upper end surface (rear surface) in FIG. 1 (A) is open, a cylindrical side wall 2A, and a disk shape. Bottom plate 2B. As shown in FIG. 1B, the opening of the case 2 is circular in plan view.
- the case 2 is a member made of lightweight aluminum having a high elastic modulus, for example, and is formed by forging.
- the material of the case 2 is not limited to a conductive material such as aluminum, and may be an insulating material.
- the bottom plate 2B includes a recess 2B1 and a step 2B2.
- Recess 2B1 has a bottom surface portion and a side wall portion, and is provided such that a predetermined direction (lateral direction in FIG. 1B) is a short direction, and a direction orthogonal to the short direction is a long direction. . That is, the recess 2B1 is provided so that both ends in the longitudinal direction reach the side wall 2A. Further, the step 2B2 is provided on both sides in the short direction of the recess 2B1.
- the bottom surface portion of the recess 2B1 becomes the main vibration region of the case 2, and the ultrasonic sensor 1 has a narrow directivity in the longitudinal direction of the recess 2B1 and a wide directivity in the lateral direction.
- the piezoelectric element 3 has a flat plate shape and spreads in the in-plane direction and vibrates when a driving voltage is applied.
- the piezoelectric element 3 is disposed inside the recess 2B1 of the case 2 and joined to the bottom plate 2B. Specifically, the piezoelectric element 3 is bonded to the bottom surface portion of the recess 2B1.
- the piezoelectric element 3 and the bottom plate 2B are joined together to form a bimorph vibrator, and the bottom plate 2B (recessed portion 2B1) bends and vibrates in the vertical direction in FIG.
- the sound absorbing material 4 is a flat plate made of polyester felt, for example, and is provided to absorb unnecessary ultrasonic waves emitted from the piezoelectric element 3 to the opening side of the case 2.
- the sound absorbing material 4 is disposed in the recess 2 ⁇ / b> B ⁇ b> 1 of the case 2 and is bonded onto the piezoelectric element 3.
- the reinforcing material 5 is a ring-shaped member having an opening at the center, and has high acoustic impedance.
- the reinforcing member 5 is made of a material having higher density and higher rigidity than the material constituting the case 2 such as stainless steel or zinc so as to function as a weight. Note that.
- the reinforcing material 5 may be made of the same material (aluminum) as the case 2 by adjusting the size such as thickness.
- the reinforcing member 5 is disposed on the bottom plate 2B of the case 2 so as to contact the inner peripheral surface of the side wall 2A on the bottom plate 2B side, that is, the thick portion, and the stepped portion 2B2.
- the rigidity of the surrounding portion surrounding the recess 2 ⁇ / b> B ⁇ b> 1 of the case 2 is increased, and the vibration in the bottom plate 2 ⁇ / b> B of the case 2 can be suppressed from being transmitted to the side wall 2 ⁇ / b> A of the case 2.
- the support member 6 is a ring-shaped member having an opening in the center, and is provided between the side wall 2 ⁇ / b> A of the case 2 and the buffer material 7 in order to support the buffer material 7 without contacting the case 2. .
- the support material 6 it is possible to suppress the vibration in the bottom plate 2 ⁇ / b> B of the case 2 from being transmitted to the buffer material 7 through the side wall 2 ⁇ / b> A.
- the buffer material 7 is a cup-shaped member made of an elastic body such as silicone rubber or urethane resin.
- the shock-absorbing material 7 is provided at the lower portion, and has a convex portion that engages with the opening of the reinforcing member 5, and an opening that is provided at the upper portion and engages with the terminal holding material 10.
- the terminal holding material 10 is an L-shaped member made of a resin such as polybutylene terephthalate (PBT), and holds the pin terminals 11A and 11B along an axis passing through the center of the opening of the case 2.
- the lower portion of the terminal holding member 10 is bent so as to engage with an opening provided in the upper portion of the cushioning member 7.
- the terminal holding material 10 has a convex portion provided on the bottom surface. Further, two through holes through which the pin terminals 11 ⁇ / b> A and 11 ⁇ / b> B are inserted are provided in the central portion of the terminal holding material 10.
- the pin terminals 11 ⁇ / b> A and 11 ⁇ / b> B are metal linear pins to which the drive voltage of the piezoelectric element 3 is applied, and are held by the terminal holding material 10. Specifically, the pin terminals 11 ⁇ / b> A and 11 ⁇ / b> B are inserted into the through holes of the terminal holding material 10, respectively. The lower ends of the pin terminals 11 ⁇ / b> A and 11 ⁇ / b> B protrude from the through hole of the terminal holding material 10 and are arranged in the opening of the case 2. The upper ends of the pin terminals 11 ⁇ / b> A and 11 ⁇ / b> B protrude from the upper end of the terminal holding member 10 and are arranged outside the case 2.
- the flexible substrate 9 has a wide band shape, and is a wiring portion that electrically connects the pin terminals 11A and 11B and the piezoelectric element 3.
- the flexible substrate 9 is bent and disposed in the opening of the case 2, and a part thereof is disposed between the support material 6 and the buffer material 7.
- the flexible substrate 9 has a first end and a second end. The first end extends along the same direction as the lower ends of the pin terminals 11A and 11B and is connected to the pin terminals 11A and 11B.
- the second end is connected to the piezoelectric element 3 by a conductive adhesive.
- the weight of the wiring portion can be reduced as compared with the case where the lead wire is connected to the piezoelectric element by solder as in a conventional ultrasonic sensor. Can do. Thereby, the vibration of the piezoelectric element 3 can be brought closer to an ideal one.
- the vibration damping material 8 is made of an elastic body such as silicone resin or urethane resin.
- the damping material 8 is filled in the case 2 and seals the lower ends of the pin terminals 11 ⁇ / b> A and 11 ⁇ / b> B and the flexible substrate 9 disposed in the opening of the case 2.
- the vibration damping material 8 is filled only in the space on the opening side of the case 2.
- the damping material 8 has a function of suppressing vibration of the side wall 2 ⁇ / b> A of the case 2 and also has a function of preventing the support material 6 and the buffer material 7 from being detached from the case 2.
- the vibration in the bottom plate 2B of the case 2 is attenuated by the sound absorbing material 4, the support material 6, and the buffer material 7, and thus almost propagates to the terminal holding material 10 and the pin terminals 11A and 11B. There is nothing. Therefore, vibration leakage from the pin terminals 11A and 11B to the external substrate that occurs when the ultrasonic sensor 1 is mounted on the external substrate is greatly reduced.
- the support material 6 and the buffer material 7 are difficult to propagate vibration, and the vibration damping material 8 is one that suppresses (vibrates) the vibration of the side wall 2A of the case 2.
- the support material 6 and the buffer material 7 preferably have a lower elastic modulus than the vibration damping material 8. More specifically, the elastic modulus includes a storage elastic modulus and a loss elastic modulus. It is preferable that the support material 6 and the buffer material 7 have a small storage elastic modulus, and the damping material 8 has a large loss elastic modulus.
- the support material 6 and the buffer material 7 are preferably made of a silicone resin (silicone rubber), and the vibration damping material 8 is preferably made of a urethane resin.
- FIG. 2A is a perspective view for explaining a detailed configuration of the piezoelectric element 3.
- FIG. 2B is a plan view of the ultrasonic sensor 1 as seen through the state in which the piezoelectric element 3 is bonded to the case 2.
- the piezoelectric element 3 includes electrodes 3A to 3D and a piezoelectric substrate 3E.
- the piezoelectric substrate 3E is made of a lead zirconate titanate piezoelectric ceramic and has a rectangular flat plate shape in plan view.
- the electrode 3A corresponds to the first electrode in the present embodiment, and is provided on the entire lower surface, which is the first surface of the piezoelectric substrate 3E.
- the electrode 3A is joined to the bottom plate 2B of the case 2. Specifically, the electrode 3A is joined to the bottom surface of the recess 2B1.
- the electrode 3B corresponds to the second electrode in the present embodiment, and is provided on a part of the upper surface which is the second surface of the piezoelectric substrate 3E.
- the electrode 3C corresponds to the third electrode in the present embodiment, and is provided on a part of the upper surface that is the second surface of the piezoelectric substrate 3E.
- the electrode 3D is provided on one side surface of the piezoelectric substrate 3E, and is connected to the electrode 3A and the electrode 3C. For this reason, the electrode 3A and the electrode 3C are electrically connected.
- a linear piezoelectric substrate exposure region parallel to the longitudinal direction of the piezoelectric substrate 3E is provided. .
- the electrode 3B and the electrode 3C are separated from each other by a predetermined distance, and are arranged in the short direction on the upper surface of the piezoelectric substrate 3E, and are not electrically connected to each other.
- the area where the electrode 3B is provided on the upper surface of the piezoelectric substrate 3E is different from the area where the electrode 3C is provided, and the area where the electrode 3B is provided is the area where the electrode 3C is provided. Is larger than the area. That is, the area of the electrode 3B is larger than that of the electrode 3C.
- the electrodes 3B and 3C are arranged side by side while being separated by a predetermined distance, so that the electrodes 3B and 3C are directly connected to the connection region 9A at the second end of the flexible substrate 9.
- the connection region 9A is connected to the electrode 3B and the electrode 3C in the center in the longitudinal direction of the piezoelectric element 3 and in the region around the electrode non-formation region. Since the electrodes 3A to 3D are configured as described above, the connection region 9A of the flexible substrate 9 is connected to the piezoelectric element 3 after the piezoelectric element 3 is bonded to the bottom plate 2B of the case. Thereby, the joining accuracy of the piezoelectric element 3 and the case 2 can be increased.
- the piezoelectric element 3 having such a configuration vibrates when a driving voltage is applied between the electrodes 3A and 3B, and a region sandwiched between the electrodes 3A and 3B in the piezoelectric substrate 3E is deformed. It will be. On the other hand, the region sandwiched between the electrodes 3A and 3C in the piezoelectric substrate 3E hardly deforms and therefore hardly contributes to vibration.
- the area of the area where the electrode 3B is provided on the upper surface, which is the second surface of the piezoelectric substrate 3E, is different from the area of the area where the electrode 3C is provided. Since the electrode 3C is provided asymmetrically, the region contributing to vibration in the piezoelectric element 3 is asymmetrical.
- the piezoelectric element 3 is joined to the concave portion 2B1 so that the longitudinal direction of the piezoelectric element 3 coincides with the longitudinal direction of the concave portion 2B1 and the short side direction thereof coincides with the short direction of the concave portion 2B1. ing. Then, the piezoelectric element 3 has a plan view of the recess 2B1 so that the center position of the short side direction of the piezoelectric element 3 is different from the center position of the short side direction of the recess 2B1, that is, the center of the short side direction of the piezoelectric element 3 is. Further, the concave portion 2B1 is disposed so as to be offset from the center in the short direction to the one side of the stepped portion 2B2. The piezoelectric element 3 is arranged such that its longitudinal center coincides with the longitudinal center of the recess 2B1.
- the center of the piezoelectric element 3 is different from the center position of the piezoelectric element 3 and the center position of the recess 2B1. Is offset from the center of the recess 2B1, and the offset dimension of the piezoelectric element 3, that is, the distance between the position of the center of the piezoelectric element 3 and the position of the center of the recess 2B1 is appropriately determined.
- the vibration efficiency and the overall sensitivity of the element 3 can be improved and the characteristics can be improved.
- a region sandwiched between the electrodes 3A and 3C in the piezoelectric substrate 3E that hardly contributes to vibration is defined as a bottom plate of the case. Since it can be arranged close to the step 2B2 that is a node of vibration in 2B, it is possible to prevent the vibration of the piezoelectric element 3 from being obstructed and bring the vibration of the ultrasonic sensor 1 closer to an ideal one. it can.
- connection region 9A at the second end of the flexible substrate 9 is connected to the electrode 3B and the electrode 3C at the center in the longitudinal direction of the piezoelectric element 3 and in the region around the electrode non-formation region. Since 9A can be arranged close to the step 2B2 that becomes a vibration node in the bottom plate 2B of the case, the vibration of the piezoelectric sensor 3 is prevented from being obstructed, and the vibration of the ultrasonic sensor 1 is made more ideal. You can get closer to things.
- the flexible substrate 9 (not shown) is drawn from the connection region 9A to the electrode 3C side. Thereby, the symmetry of the vibration of the piezoelectric element 3 can be improved, and the vibration of the ultrasonic sensor 1 can be brought closer to an ideal one.
- the recess 2B1 has a dimension in the short direction of 7.0 mm.
- the piezoelectric element 3 has a short-side dimension of 5.2 mm and a long-side dimension of 6.5 mm.
- the electrode 3C has a dimension in the short (width) direction of 0.9 mm.
- the dimension in the short (width) direction of the electrode non-formation region at the boundary between the electrode 3C and the electrode 3B is 0.4 mm.
- the electrode 3B has a short (width) dimension of 3.9 mm.
- the offset dimension between the center of the piezoelectric element 3 and the center of the recess 2B1 is 0.4 mm. That is, the center of the recess 2B1 is positioned at 2.2 mm from the end of the piezoelectric element 3 on the electrode 3B side and at a position of 3.0 mm from the end on the electrode 3C side.
- FIG. 3A shows the relationship between the electromechanical coupling coefficient Kp /% in the bimorph vibrator including the case 2 and the piezoelectric element 3 and the offset dimension (element shift amount) of the piezoelectric element 3 in the dimension setting example described above.
- FIG. 3A shows the relationship between the electromechanical coupling coefficient Kp /% in the bimorph vibrator including the case 2 and the piezoelectric element 3 and the offset dimension (element shift amount) of the piezoelectric element 3 in the dimension setting example described above.
- the offset dimension of the piezoelectric element 3 is larger than the configuration in which the offset dimension of the piezoelectric element 3 is zero.
- the electromechanical coupling coefficient Kp /% becomes large.
- the electromechanical coupling coefficient Kp /% is maximized when the offset dimension of the piezoelectric element 3 is a predetermined value (0.4 mm), and in the configuration in which the offset dimension of the piezoelectric element 3 is larger than the predetermined value, the electromechanical coupling coefficient Kp / % Is smaller than the maximum value. Therefore, at least in terms of vibration efficiency of the ultrasonic sensor, it can be seen that vibration efficiency can be maximized by setting the piezoelectric element 3 to a predetermined offset dimension.
- FIG. 3B is a diagram showing the relationship between the total sensitivity Vpp of the ultrasonic sensor 1 and the offset dimension of the piezoelectric element 3 in the above dimension setting example.
- the total sensitivity Vpp of the ultrasonic sensor 1 has a positive correlation with the offset dimension of the piezoelectric element 3, and the greater the offset dimension, the higher the total sensitivity Vpp. Accordingly, it can be seen that at least in terms of the total sensitivity Vpp of the ultrasonic sensor 1, it is desirable that the offset dimension of the piezoelectric element 3 be large (for example, 0.5 mm).
- an example of setting the offset dimension of the piezoelectric element 3 described above is an example of setting the offset dimension to 0.4 mm. It was.
- the pulling-out direction of the flexible substrate 9 is the longitudinal direction of the piezoelectric element 3
- interference between the flexible substrate 9 and the side wall 2A of the case 2 is less likely to occur.
- the offset dimension may be increased to the limit, and the overall sensitivity of the ultrasonic sensor 1 can be further improved.
- FIG. 4 is a schematic cross-sectional view of the ultrasonic sensor 21 according to the present embodiment.
- the ultrasonic sensor 21 includes lead wires 29A and 29B instead of the flexible substrate 9 of the ultrasonic sensor 1 according to the above-described embodiment.
- the other configuration of the ultrasonic sensor 21 is the same as that of the ultrasonic sensor 1 according to the above-described embodiment.
- the lead wires 29A and 29B are directly connected to the electrodes 3B and 3C (not shown) of the piezoelectric element 3, respectively. In this way, the ultrasonic sensor 21 may be configured. Even in this case, the present invention can be suitably implemented by directly connecting the piezoelectric element 3 and the pin terminals 11A and 11B without using the case 2 and by arranging the piezoelectric element 3 in an offset manner.
- the electrodes 3 ⁇ / b> B and 3 ⁇ / b> C are provided side by side in the longitudinal direction of the piezoelectric element 33 while being separated by a predetermined distance.
- the piezoelectric element 33 is arranged offset in the longitudinal direction of the recess 2B1. In such a configuration, the symmetry of the directional beam can be enhanced in the short direction of the recess 2B1. Further, a region sandwiched between the electrode 3A (not shown) and the electrode 3C in the piezoelectric substrate 3E (not shown) that hardly contributes to vibration does not interfere with the side wall 2A or the step 2B2, and the piezoelectric element 33 The size can be increased.
- the ultrasonic sensor 41 includes a piezoelectric element 43 instead of the piezoelectric element 3 of the above-described embodiment.
- the other configuration of the ultrasonic sensor 41 is the same as that of the ultrasonic sensor 1 according to the above-described embodiment.
- FIG. 5B is a plan view of the ultrasonic sensor 41 as seen through the state in which the piezoelectric element 43 is bonded to the case 2.
- the electrode 3 ⁇ / b> B and the electrode 3 ⁇ / b> C are provided side by side in the short direction of the piezoelectric element 43 while being separated by a predetermined distance.
- the piezoelectric element 43 is arranged with its own longitudinal direction as the short direction of the recess 2B1 and offset in the longitudinal direction of the recess 2B1.
- the ultrasonic sensor 51 includes a piezoelectric element 53 instead of the piezoelectric element 3 of the above-described embodiment.
- the other configuration of the ultrasonic sensor 51 is the same as that of the ultrasonic sensor 1 according to the above-described embodiment.
- FIG. 5C is a plan view of the ultrasonic sensor 51 as seen through the state in which the piezoelectric element 53 is bonded to the case 2.
- the electrode 3 ⁇ / b> B and the electrode 3 ⁇ / b> C are provided side by side in the longitudinal direction of the piezoelectric element 53 while being separated by a predetermined distance.
- the piezoelectric element 53 is arranged with its own longitudinal direction as the short direction of the recess 2B1, and offset in the short direction of the recess 2B1.
- the present invention can be implemented, but the specific configuration of the ultrasonic sensor is not limited to the above.
- any specific shape or material such as cushioning material, support material, reinforcement material, support material, sound absorbing material may be used, and cushioning material, support material, reinforcement material, support material, sound absorption material may be It is not always necessary to provide each.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Transducers For Ultrasonic Waves (AREA)
Abstract
Description
図1(A)は、本発明の第1の実施形態に係る超音波センサ1の断面図である。図1(B)は、超音波センサ1の平面図である。なお、図1(A)は、図1(B)中にA-A’で示す位置における断面を示す。図1(B)は、超音波センサ1の背面を示す。
次に、本発明の第2の実施形態に係る超音波センサ21について説明する。
次に、本発明の変形例に係る超音波センサ31~51について説明する。
圧電素子33では、電極3Bと電極3Cとは、所定の間隔離れて、圧電素子33の長手方向に並べて設けられている。圧電素子33は、凹部2B1の長手方向にオフセットして配置されている。このような構成では、凹部2B1の短手方向で指向性ビームの対称性を高めることができる。また、振動にほとんど寄与しない圧電基板3E(図示せず)における電極3A(図示せず)と電極3Cとに挟まれる領域が、側壁2Aや段部2B2に干渉することが無く、圧電素子33のサイズが大きくすることができる。
2…ケース
2A…側壁
2B…底板
2B1…凹部
2B2…段部
3,33,43,53…圧電素子
3A~3D…駆動電極
3E…圧電基板
4…吸音材
5…補強材
6…支持材
7…緩衝材
8…制振材
9…フレキシブル基板
9A…接続領域
10…端子保持材
11A,11B…ピン端子
29A,29B…リード線
Claims (4)
- 振動領域である底面部を有する有底筒状のケースと、
第1の面と前記第1の面と対向する第2の面とを有する圧電基板と、前記第1の面に設けられている第1の電極と、前記第2の面の一部に設けられている第2の電極と、前記第2の面の一部に前記第2の電極と離れて設けられており、前記第1の電極と接続されている第3の電極とを有し、前記第1の電極が前記底面部に接合され、前記底面部を平面視して自らの中心が前記振動領域の中心と異なる位置に配置されている圧電素子と、
を備える、超音波センサ。 - 前記圧電基板の前記第2の面における前記第2の電極が設けられている領域の面積と前記第3の電極が設けられている領域の面積とが異なる、請求項1に記載の超音波センサ。
- 前記圧電素子を平面視して、前記第2の電極と前記第3の電極とが非対称に設けられている、請求項1に記載の超音波センサ。
- 前記振動領域は、前記底面部を平面視して、長手方向と短手方向とを有する平面形状であり、
前記第2の電極と前記第3の電極とは前記短手方向に配列されている、請求項1~3のいずれかに記載の超音波センサ。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2013536315A JP5672389B2 (ja) | 2011-09-30 | 2012-09-26 | 超音波センサ |
KR1020147007993A KR101528890B1 (ko) | 2011-09-30 | 2012-09-26 | 초음파 센서 |
CN201280047255.2A CN103828395B (zh) | 2011-09-30 | 2012-09-26 | 超声波传感器 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2011217695 | 2011-09-30 | ||
JP2011-217695 | 2011-09-30 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2013047544A1 true WO2013047544A1 (ja) | 2013-04-04 |
Family
ID=47995575
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2012/074620 WO2013047544A1 (ja) | 2011-09-30 | 2012-09-26 | 超音波センサ |
Country Status (4)
Country | Link |
---|---|
JP (1) | JP5672389B2 (ja) |
KR (1) | KR101528890B1 (ja) |
CN (1) | CN103828395B (ja) |
WO (1) | WO2013047544A1 (ja) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2016147917A1 (ja) * | 2015-03-16 | 2016-09-22 | 株式会社村田製作所 | 超音波センサ |
JP2018093449A (ja) * | 2016-12-07 | 2018-06-14 | キヤノン株式会社 | 超音波プローブ、超音波ユニット及び被検体情報取得装置 |
JP2020108113A (ja) * | 2018-12-28 | 2020-07-09 | 京セラ株式会社 | 超音波センサ |
WO2021171819A1 (ja) * | 2020-02-26 | 2021-09-02 | 株式会社村田製作所 | 超音波センサ |
JP2021141475A (ja) * | 2020-03-06 | 2021-09-16 | Tdk株式会社 | 圧電デバイス |
WO2021187243A1 (ja) * | 2020-03-20 | 2021-09-23 | 株式会社Soken | 超音波トランスデューサ、超音波センサ、物体検知装置、物体検知方法、および物体検知プログラム |
JP2021183951A (ja) * | 2020-05-22 | 2021-12-02 | 株式会社Soken | 超音波センサ取付構造 |
JP2021197617A (ja) * | 2020-06-12 | 2021-12-27 | 株式会社Soken | 超音波トランスデューサ |
US11397254B2 (en) * | 2018-08-09 | 2022-07-26 | Seiko Epson Corporation | Ultrasonic device and ultrasonic sensor |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104677399B (zh) * | 2014-11-24 | 2017-12-05 | 麦克思智慧资本股份有限公司 | 超声波传感器 |
WO2019087266A1 (ja) * | 2017-10-30 | 2019-05-09 | オリンパス株式会社 | 超音波振動子、超音波内視鏡、及び超音波振動子の製造方法 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06184A (ja) * | 1992-06-19 | 1994-01-11 | Matsushita Electric Ind Co Ltd | 超音波探触子 |
JP2000152387A (ja) * | 1998-11-05 | 2000-05-30 | Nippon Ceramic Co Ltd | 超音波送受波器 |
JP2008531110A (ja) * | 2005-02-22 | 2008-08-14 | ヒューマンスキャン・カンパニー・リミテッド | 積層型超音波トランスデューサ及びその製造方法 |
WO2011090201A1 (ja) * | 2010-01-25 | 2011-07-28 | 株式会社村田製作所 | 超音波振動装置 |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001128293A (ja) * | 1999-10-28 | 2001-05-11 | Murata Mfg Co Ltd | 圧電装置 |
JP4809410B2 (ja) * | 2008-09-29 | 2011-11-09 | 日本電波工業株式会社 | 圧電デバイスとその製造方法 |
-
2012
- 2012-09-26 KR KR1020147007993A patent/KR101528890B1/ko active IP Right Grant
- 2012-09-26 CN CN201280047255.2A patent/CN103828395B/zh active Active
- 2012-09-26 WO PCT/JP2012/074620 patent/WO2013047544A1/ja active Application Filing
- 2012-09-26 JP JP2013536315A patent/JP5672389B2/ja active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06184A (ja) * | 1992-06-19 | 1994-01-11 | Matsushita Electric Ind Co Ltd | 超音波探触子 |
JP2000152387A (ja) * | 1998-11-05 | 2000-05-30 | Nippon Ceramic Co Ltd | 超音波送受波器 |
JP2008531110A (ja) * | 2005-02-22 | 2008-08-14 | ヒューマンスキャン・カンパニー・リミテッド | 積層型超音波トランスデューサ及びその製造方法 |
WO2011090201A1 (ja) * | 2010-01-25 | 2011-07-28 | 株式会社村田製作所 | 超音波振動装置 |
Cited By (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2016147917A1 (ja) * | 2015-03-16 | 2016-09-22 | 株式会社村田製作所 | 超音波センサ |
JP2018093449A (ja) * | 2016-12-07 | 2018-06-14 | キヤノン株式会社 | 超音波プローブ、超音波ユニット及び被検体情報取得装置 |
US11397254B2 (en) * | 2018-08-09 | 2022-07-26 | Seiko Epson Corporation | Ultrasonic device and ultrasonic sensor |
JP7061559B2 (ja) | 2018-12-28 | 2022-04-28 | 京セラ株式会社 | 超音波センサ |
JP2020108113A (ja) * | 2018-12-28 | 2020-07-09 | 京セラ株式会社 | 超音波センサ |
DE112021000436T5 (de) | 2020-02-26 | 2022-10-13 | Murata Manufacturing Co., Ltd. | Ultraschallsensor |
JPWO2021171819A1 (ja) * | 2020-02-26 | 2021-09-02 | ||
JP7327637B2 (ja) | 2020-02-26 | 2023-08-16 | 株式会社村田製作所 | 超音波センサ |
WO2021171819A1 (ja) * | 2020-02-26 | 2021-09-02 | 株式会社村田製作所 | 超音波センサ |
JP7452107B2 (ja) | 2020-03-06 | 2024-03-19 | Tdk株式会社 | 圧電デバイス |
JP2021141475A (ja) * | 2020-03-06 | 2021-09-16 | Tdk株式会社 | 圧電デバイス |
JP7413870B2 (ja) | 2020-03-20 | 2024-01-16 | 株式会社Soken | 超音波センサ、物体検知装置、および物体検知プログラム |
WO2021187243A1 (ja) * | 2020-03-20 | 2021-09-23 | 株式会社Soken | 超音波トランスデューサ、超音波センサ、物体検知装置、物体検知方法、および物体検知プログラム |
JP2021150872A (ja) * | 2020-03-20 | 2021-09-27 | 株式会社Soken | 超音波トランスデューサ、超音波センサ、物体検知装置、物体検知方法、および物体検知プログラム |
US12044808B2 (en) | 2020-03-20 | 2024-07-23 | Denso Corporation | Ultrasonic transducer, ultrasonic sensor, object detection apparatus, object detection method, and object detection program |
JP2021183951A (ja) * | 2020-05-22 | 2021-12-02 | 株式会社Soken | 超音波センサ取付構造 |
JP7413921B2 (ja) | 2020-05-22 | 2024-01-16 | 株式会社Soken | 超音波センサ取付構造 |
JP2021197617A (ja) * | 2020-06-12 | 2021-12-27 | 株式会社Soken | 超音波トランスデューサ |
JP7435282B2 (ja) | 2020-06-12 | 2024-02-21 | 株式会社Soken | 超音波トランスデューサ |
Also Published As
Publication number | Publication date |
---|---|
CN103828395B (zh) | 2017-05-17 |
JPWO2013047544A1 (ja) | 2015-03-26 |
CN103828395A (zh) | 2014-05-28 |
JP5672389B2 (ja) | 2015-02-18 |
KR101528890B1 (ko) | 2015-06-15 |
KR20140050749A (ko) | 2014-04-29 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5672389B2 (ja) | 超音波センサ | |
JP4086091B2 (ja) | 超音波トランスデューサ | |
US7692367B2 (en) | Ultrasonic transducer | |
JP4618165B2 (ja) | 超音波センサ | |
JP5590248B2 (ja) | 超音波センサ | |
WO2012164879A1 (ja) | 超音波送受波器および超音波流量計 | |
EP1096469B1 (en) | Ultrasonic vibration apparatus | |
JPWO2007102460A1 (ja) | 超音波センサおよびその製造方法 | |
JP5522311B2 (ja) | 超音波センサおよびその製造方法 | |
JP2009058298A (ja) | 超音波センサ | |
JPWO2007091609A1 (ja) | 超音波センサ | |
US9968966B2 (en) | Electroacoustic transducer | |
JP2008311736A (ja) | 超音波センサ | |
JPWO2005009075A1 (ja) | 超音波送受波器 | |
US11583896B2 (en) | Sound transducer including a piezoceramic transducer element integrated in a vibratory diaphragm | |
JP5414427B2 (ja) | 超音波送受信器 | |
JP2002262383A (ja) | 超音波振動子 | |
JP4182156B2 (ja) | 超音波送受波器及び電子機器 | |
JP2014027516A (ja) | 超音波送受波器 | |
JP7088099B2 (ja) | 超音波センサ | |
JP4915597B2 (ja) | 超音波センサ | |
WO2023203879A1 (ja) | 超音波トランスデューサおよびその製造方法 | |
JP4768684B2 (ja) | 超音波センサ | |
JP2000023290A (ja) | 超音波センサ |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
ENP | Entry into the national phase |
Ref document number: 2013536315 Country of ref document: JP Kind code of ref document: A |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 12834720 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 20147007993 Country of ref document: KR Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 12834720 Country of ref document: EP Kind code of ref document: A1 |