Sensor for hydrophone

Abstract

The utility model relates to the technical field of sensors, and particularly discloses a sensor for a hydrophone, which comprises a support ring, two support plates and two piezoelectric ceramics. Wherein the two supporting plates are arranged at the two ends of the supporting ring correspondingly, and a sealing cavity is defined by the two supporting plates and the supporting ring; the piezoelectric ceramics are provided with at least two layers of ceramic pieces which are arranged in a laminated mode, and the two piezoelectric ceramics are arranged on the opposite side faces of the two supporting plates respectively and located outside the sealing cavity. By means of the arrangement of the structure, holes do not need to be formed in the supporting ring, the preparation process is simplified, and cost is reduced; meanwhile, the piezoelectric ceramics on one supporting plate are fixed in a one-time bonding mode, loss is reduced, the electromechanical coupling coefficient of the piezoelectric ceramics is remarkably improved, and therefore the sensitivity is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to sensor technical field especially relates to a sensor for hydrophone. BACKGROUND

[0002] It is known that piezoelectric material is a kind of material that can convert mechanical energy and electrical energy, due to its unique physical properties, piezoelectric material has wide application in sensor technology field, especially in underwater acoustic detection field.

[0003] Underwater acoustic detection is a kind of technology that uses the characteristics of sound wave propagation in water to detect and identify objects in water, and is widely used in ocean exploration, military, environmental protection and other fields. The existing piezoelectric sensor for hydrophone usually includes single-layer piezoelectric ceramic, bottom metal plate and support ring, and is sealed by silicone. In order to improve the output voltage, two single-layer piezoelectric ceramics are usually used to be attached to the surface of the metal plate in series. Since the bottom metal plate is installed at the end of the support ring, when the wire inside the support ring is led out, it needs to be punched on the side wall of the support ring, which is complex in process and affects the sealing. In addition, the bonding of two single-layer piezoelectric ceramics increases the loss and reduces the piezoelectric ceramic electromechanical coupling coefficient, which leads to obvious decrease in sensitivity.

[0004] Therefore, it is urgent to study a sensor for hydrophone to solve the above problems. UTILITY MODEL CONTENT

[0005] The utility model aims at providing a sensor for hydrophone to solve the problem of poor sealing and poor sensitivity caused by punching of support ring in prior art.

[0006] To achieve the above purpose, the utility model adopts the following technical scheme:

[0007] The sensor for hydrophone comprises:

[0008] Support ring;

[0009] Two support plates, two support plates are respectively arranged at both ends of the support ring, and two support plates and the support ring form a sealed cavity;

[0010] Two piezoelectric ceramics, the piezoelectric ceramic has at least two layers of ceramic sheets arranged in stack, two piezoelectric ceramics are arranged on the opposite sides of two support plates respectively, and are located outside the sealed cavity.

[0011] As an optional technical scheme of the sensor for hydrophone, the piezoelectric ceramic comprises a first ceramic sheet and a second ceramic sheet arranged in stack, and the polarization directions of the first ceramic sheet and the second ceramic sheet are opposite. Or,

[0012] The piezoelectric ceramic comprises three or more ceramic sheets arranged in a stack, and the polarization directions of two adjacent ceramic sheets are opposite.

[0013] As an optional technical solution of the sensor for the hydrophone, each piezoelectric ceramic is welded with a positive electrode lead wire and a negative electrode lead wire, the two positive electrode lead wires on the two piezoelectric ceramics are connected in parallel, and the two negative electrode lead wires on the two piezoelectric ceramics are connected in parallel.

[0014] As an optional technical solution of the sensor for the hydrophone, the piezoelectric ceramic is bonded to the surface of the support plate by silicone or a silicone pad.

[0015] As an optional technical solution of the sensor for the hydrophone, the support plate is bonded to the end face of the support ring by any one of silicone, epoxy resin glue, UV glue or a silicone pad.

[0016] As an optional technical solution of the sensor for the hydrophone, the outer periphery of the support plate and the support ring is sealed by waterproof silicone at the joint between the two.

[0017] As an optional technical solution of the sensor for the hydrophone, the outer periphery of the support plate and the support ring is sealed by waterproof silicone at the joint between the two.

[0018] As an optional technical solution of the sensor for the hydrophone, the support plate is made of metal; and / or,

[0019] The support ring is made of metal.

[0020] As an optional technical solution of the sensor for the hydrophone, the support ring is made of copper.

[0021] As an optional technical solution of the sensor for the hydrophone, the internal electrode of the piezoelectric ceramic is a silver-palladium electrode or a nickel electrode.

[0022] The beneficial effects of the utility model are as follows:

[0023] The utility model provides a sensor for a hydrophone, the sensor for the hydrophone includes a support ring, two support plates and two piezoelectric ceramics, wherein the two support plates are arranged at the two ends of the support ring to form a sealed cavity, the two piezoelectric ceramics have at least two layers of ceramic sheets arranged in a stack, the two piezoelectric ceramics are arranged on two opposite surfaces of the two support plates, the support ring does not need to be opened, the preparation process is simplified, and the cost is reduced, meanwhile, the piezoelectric ceramic on a support plate is fixed by one-time bonding, the loss is reduced, the piezoelectric ceramic machine electric coupling coefficient is improved significantly, and the sensitivity is improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained according to the contents of the embodiments of the present application and these drawings without any creative effort.

[0025] Figure 1 The structure diagram of the piezoelectric ceramic in the embodiments of the present application is shown.

[0026] Figure 2 The structure diagram of the sensor for hydrophone in the embodiments of the present application is shown.

[0027] In the drawings:

[0028] 100, support ring;

[0029] 200, support plate;

[0030] 300, piezoelectric ceramic; 310, first upper surface electrode; 320, second upper surface electrode; 330, internal electrode; 340, lower surface electrode; 350, first side surface electrode; 360, second side surface electrode;

[0031] 410, positive electrode lead; 420, negative electrode lead. DETAILED DESCRIPTION

[0032] Before any embodiments of the present application are explained in detail, it is to be understood that the application is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the above-described drawings.

[0033] In the present application, the terms "comprising", "containing", "having" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0034] In the present application, the term "and / or" is a description of the association relationship between the associated objects, which means that there can be three kinds of relationships. For example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents a "and / or" relationship between the front and rear associated objects.

[0035] In this application, the terms "connect," "couple," "coupled," "mount," and "mounting" can be direct or indirect, and can include mechanical, electrical, and / or logical connectivity. In addition, "connect" and "coupled" are not restricted to physical or mechanical connections or couplings, and can include electrical connectivity or couplings.

[0036] In this application, the use of relative terms (e.g., "about," "approximately," "substantially," etc.) in connection with a quantity or condition will be understood by those of ordinary skill to include the stated value and possess the meaning indicated by the context. For example, the relative terms include at least an amount of error associated with a measurement of a particular value, a tolerance in a particular value resulting from manufacturing, assembly, use, etc. Such terms should also be considered as disclosing a range that is defined by the absolute values of the two endpoints. The relative terms can refer to a percentage (e.g., 1%, 5%, 10% or more) of the indicated value plus or minus. Values that do not employ a relative term should also be disclosed as particular values with tolerances. In addition, "substantially" when used in the context of expressing a relative angular positional relationship (e.g., substantially parallel, substantially perpendicular) can refer to plus or minus a certain number of degrees (e.g., 1 degree, 5 degrees, 10 degrees or more) from the indicated angle.

[0037] In this application, those of ordinary skill will appreciate that a function performed by a component can be performed by one component, multiple components, one part, or multiple parts.

[0038] In this application, the terms "upper," "lower," "left," "right," "front," "back," and the like describe the orientation and position as shown in the figures, and should not be construed to limit the embodiments of the present application. In addition, it will be understood that, when an element is referred to as being "on" or "under" another element, it can be directly on or under the other element, or an intervening element can also be present. It will also be understood that the terms "upper," "lower," "left," "right," "front," "back," and the like refer not only to the positive directions, but also to the side directions. For example, "lower" can include "directly below," "left below," "right below," "front below," and "back below," etc.

[0039] As Figure 1 and Figure 2As shown, the embodiment provides a sensor for hydrophone, which comprises a support ring 100, two support plates 200 and two piezoelectric ceramics 300. Wherein, the two support plates 200 are respectively arranged at two ends of the support ring 100, and the two support plates 200 and the support ring 100 enclose a sealed cavity; the two piezoelectric ceramics 300 each have at least two layers of ceramic sheets arranged in a stack, and the two piezoelectric ceramics 300 are respectively arranged on the opposite sides of the two support plates 200 and are located outside the sealed cavity.

[0040] With the above structure, the support ring 100 does not need to be opened, which simplifies the manufacturing process and reduces the cost; at the same time, the piezoelectric ceramic 300 on one support plate 200 is fixed by one-time bonding, which reduces the loss and significantly improves the electromechanical coupling coefficient of the piezoelectric ceramic 300, thereby improving the sensitivity.

[0041] In order to further improve the sensitivity, in some embodiments, the piezoelectric ceramic 300 comprises a first ceramic sheet and a second ceramic sheet arranged in a stack, and the polarization directions of the first ceramic sheet and the second ceramic sheet are opposite. When subjected to sound wave pressure, the first ceramic sheet on the upper layer releases the electric charge, and the second ceramic sheet on the lower layer absorbs the electric charge, thereby having the characteristics of fast response speed and high sensitivity.

[0042] In other embodiments, there can be more layers of ceramic sheets to further improve the response speed and sensitivity. Specifically, the piezoelectric ceramic 300 comprises three or more ceramic sheets arranged in a stack, and the polarization directions of the two adjacent ceramic sheets are opposite, so as to further increase the response speed and sensitivity.

[0043] In order to improve the convenience of use, in some embodiments, each piezoelectric ceramic 300 is welded with a positive electrode lead 410 and a negative electrode lead 420, and the two positive electrode leads 410 on the two piezoelectric ceramics 300 are connected in parallel, and the two negative electrode leads 420 on the two piezoelectric ceramics 300 are connected in parallel. The above arrangement enables the output voltage of the two piezoelectric ceramics 300 to be increased, thereby improving the detection sensitivity.

[0044] In some embodiments, the piezoelectric ceramic 300 is bonded to the surface of the support plate 200 by silicone or silicone pad. The bonding mode enables high assembly efficiency and firm connection between the piezoelectric ceramic 300 and the support plate 200. The support plate 200 is bonded to the end face of the support ring 100 by any one of silicone, epoxy resin glue, UV glue or silicone pad. The bonding mode enables high assembly efficiency and firm connection between the support ring 100 and the support plate 200; in addition, when the silicone or silicone pad is bonded between the support plate 200 and the support ring 100, it can ensure the sealing between the support ring 100 and the support plate 200, and also help the support plate 200 to easily deform after receiving the sound wave, thereby driving the piezoelectric ceramic 300 to deform and improving the detection sensitivity.

[0045] To further improve the sealing performance of the sealed cavity, in some embodiments, the outer periphery of the support plate 200 and the support ring 100 is sealed by waterproof silicone at the joint between the two. Of course, in other embodiments, the support plate 200 and the support ring 100 can be bonded and then placed in a protective shell, and then a sealant is poured into the protective shell to complete the packaging, thereby achieving better sealing effect.

[0046] To improve the sealing effect and the convenience of use, in some embodiments, the outer contour of the support plate 200 and the support ring 100 is circular, and the outer diameters are the same, and the two are arranged concentrically. This arrangement aligns the outer peripheral walls of the support plate 200 and the support ring 100 in the axial direction of the support ring 100, facilitating the application of sealant.

[0047] Regarding the material of the support plate 200 and the support ring 100, in the first embodiment of the present embodiment, the support plate 200 is of metal material. In the second embodiment of the present embodiment, the support ring 100 is of metal material. In the third embodiment of the present embodiment, the support plate 200 is of metal material, and the support ring 100 is of metal material. Exemplarily, the support ring 100 is of copper material.

[0048] In some embodiments, the support plate 200 can also be of other materials that have certain strength and can produce elastic deformation. Exemplarily, the support plate 200 is of plastic material. Yet another exemplarily, the support plate 200 is of high polymer material.

[0049] The piezoelectric ceramic 300 includes a first upper surface electrode 310, a second upper surface electrode 320, an internal electrode 330, a lower surface electrode 340, a first side surface electrode 350, and a second side surface electrode 360, wherein the first upper surface electrode 310 and the lower surface electrode 340 are connected through the first side surface electrode 350, and the internal electrode 330 and the second upper surface electrode 320 are connected through the second side surface electrode 360.

[0050] To ensure the electrical conductivity while improving the corrosion resistance, in some embodiments, the internal electrode 330 of the piezoelectric ceramic 300 is a silver-palladium electrode or a nickel electrode. The external electrodes (various surfaces, sides) of the piezoelectric ceramic 300 are silver electrodes.

[0051] In the present embodiment, the preparation method of the piezoelectric ceramic 300 is briefly introduced as follows: first, a PZT or KNN green body with a thickness of 0.25 mm is printed with a silver-palladium electrode as an internal electrode 330; the green body printed with the internal electrode 330 is stacked with a green body without electrode pattern; the two stacked blocks are placed in an isostatic pressing device, and 200 MPa is adopted for pressure retention for 10 minutes; the blocks after isostatic pressing are cut into individual independent patterns using a mold.

[0052] The cut pattern is put into a box sintering furnace; 1100 DEG C is kept for 5H for sintering. The sintered piezoelectric ceramic 300 is printed with silver paste for external electrodes; the piezoelectric ceramic 300 substrate printed and dried with silver paste is put into a mesh belt sintering furnace, and back silver sintering is carried out at 600 DEG C for 10 min. The sintered piezoelectric ceramic 300 is placed in a silicon oil bath to apply an electric field, the applied electric field strength is 600V, and the pressure is kept for 10 min; the applied polarization temperature is 120 DEG C oil bath heating. The polarized piezoelectric ceramic 300 substrate is placed in a constant temperature and humidity chamber with a temperature of 23 DEG C and a humidity of 45%, and is naturally placed and aged for 48H.

[0053] The hydrophone sensor in the embodiment is placed in a 172Hz sound field, and the output voltage signal peak value is 268mV; the period T is 5.824mS, and the response speed and the output voltage are excellent, so the hydrophone sensor can be widely applied in object detection industries such as oceans and lakes.

[0054] Obviously, the above embodiments of the utility model are only examples for clearly explaining the utility model, and are not the limitation of the embodiments of the utility model. For ordinary skilled in the art, various obvious changes, re-adjustment and replacement can be carried out without departing from the protection scope of the utility model. Here, all the embodiments need not to be exhausted. Any modification, equivalent replacement and improvement within the spirit and principle of the utility model should be included in the protection scope of the utility model claim.

Claims

1. A sensor for hydrophones, characterized in that, include: Support ring (100); Two support plates (200) are respectively disposed at both ends of the support ring (100), and the two support plates (200) and the support ring (100) form a sealed cavity; Two piezoelectric ceramics (300), each having at least two layers of stacked ceramic sheets, are respectively disposed on opposite sides of the two support plates (200) and both are located outside the sealing cavity.

2. The sensor for a hydrophone according to claim 1, characterized in that, The piezoelectric ceramic (300) comprises a first ceramic sheet and a second ceramic sheet arranged in a stacked manner, wherein the polarization directions of the first ceramic sheet and the second ceramic sheet are opposite; or, The piezoelectric ceramic (300) comprises three or more ceramic plates arranged in a stack, with adjacent ceramic plates having opposite polarization directions.

3. The sensor for a hydrophone according to claim 1, characterized in that, Each of the piezoelectric ceramics (300) is welded with a positive electrode wire (410) and a negative electrode wire (420), the two positive electrode wires (410) on the two piezoelectric ceramics (300) are connected in parallel, and the two negative electrode wires (420) on the two piezoelectric ceramics (300) are connected in parallel.

4. The sensor for a hydrophone according to claim 1, characterized in that, The piezoelectric ceramic (300) is bonded to the surface of the support plate (200) by silicone or silicone pad.

5. The sensor for a hydrophone according to any one of claims 1 to 4, characterized in that, The support plate (200) is bonded to the end face of the support ring (100) by any one of silicone, epoxy resin adhesive, UV adhesive or silicone pad.

6. The sensor for a hydrophone according to claim 5, characterized in that, The outer periphery of the support plate (200) and the support ring (100) are sealed at their joint with waterproof silicone.

7. The sensor for a hydrophone according to claim 1, characterized in that, The outer contours of the support plate (200) and the support ring (100) are both circular and have the same outer diameter, and they are arranged concentrically.

8. The sensor for a hydrophone according to claim 1, characterized in that, The support plate (200) is made of metal; and / or, The support ring (100) is made of metal.

9. The sensor for a hydrophone according to claim 8, characterized in that, The support ring (100) is made of copper.

10. The sensor for a hydrophone according to claim 1, characterized in that, The internal electrode (330) of the piezoelectric ceramic (300) is a silver-palladium electrode or a nickel electrode.

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