CN107231594A - Conformal driving IV type flextensional transducers - Google Patents

Abstract

The invention provides a conformal drive type IV flextensional transducer, which includes a flextensional housing 1, a ceramic arc 2, a rubber pad 3, an upper cover 4, a lower cover 5, a connecting screw 6, a nut 7, The watertight cable head 8; the inner inlaid opening 9 of the flexural shell 1 is connected with the ceramic arc 2 by driving and matching, and the upper and lower end surfaces are connected with the rubber pad 3; the upper and lower surfaces of the rubber pad 3 are in close contact with the upper cover plate 4 and the lower cover plate 5, By connecting the screw rod 7 to form the overall structure of the conformal drive type IV flexural transducer, pressure is applied to achieve watertight characteristics; the upper cover plate 4 is provided with an electrical connection hole 11, and a watertight cable head 8 is provided on the electrical connection hole 11. The present invention adopts the ceramic circular arc 2 active drive and the IV-type flexural shell structure to realize the conformal drive mode, and utilizes the conformal driven flexural shell to have the characteristic of lower bending vibration frequency, so that the transducer can achieve lower Characteristics of resonant frequency operation.

Description

Conformally Driven Type IV Flextensional Transducers

technical field

The invention belongs to the field of low-frequency active detection, and in particular relates to a conformal drive type IV flexural transducer.

Background technique

Sound waves are the only energy carrier known to man so far that can be transmitted over long distances in seawater. Whether it is military operations or ocean development, sound waves are used as the medium for carrying information. As a general-purpose equipment for underwater sound generation, underwater acoustic transducers need to be improved according to the needs of the times.

In recent years, the country's desire to develop a maritime strategic power has become stronger and the ocean development has become more extensive, which requires the corresponding underwater acoustic equipment and technology to develop more rapidly. The 21st century is the age of the ocean. Ship sonar equipment is becoming more and more important. It has become the most important underwater acoustic combat system on naval ships. These submarines are equipped with good noise reduction equipment, which makes traditional passive sonar detection more and more difficult. The detection distance is getting closer and closer, and the safety protection ability is almost disappearing, which requires the use of active sonar to detect quiet submarines at a long distance. Increase the detection distance and increase the combat deployment time of our submarines. As the most important part of the low-frequency active sonar system, the design of the low-frequency transmitting transducer has been paid more and more attention by researchers at home and abroad. However, the size of the transducer is too large, the radiation impedance is relatively low, and the mutual Problems such as radiation effects and deep water limitations still need to be solved through continuous advancement of technological means. At the same time, with the widespread application of underwater small target platforms and their sonars in recent years, the demand for small-sized low-frequency active detection transducers is more urgent, so it is necessary to study low-frequency, small-sized, high-power transducers. especially important.

At present, among all low-frequency and high-power transducer types, the flextensional transducer uses the bending vibration of the shell to achieve low-frequency characteristics, so compared with other types of transducers, the structure size is small and the weight is light, while the flextensional transducer’s The radiation area of the shell accounts for a large proportion of the total surface area, and it has a displacement amplification effect, which makes it have a relatively large sound power, so it has become a commonly used low-frequency underwater acoustic transducer. However, with the new demands in application fields such as underwater acoustic detection in recent years, the application frequency of transducers is getting lower and lower. Generally speaking, the lower the operating frequency of the underwater acoustic transducer, the greater the size and weight, and the correspondingly higher processing difficulty and cost. At present, the weight of transducers used in the 100-500Hz frequency band is basically more than several hundred kilograms, and there are generally problems of large volume and heavy weight. Although there is an increasingly strong demand for small-volume low-frequency transducers, domestic and foreign experts have not done much research on further reducing the operating frequency and small size of flextensional transducers, mainly from the perspective of driving materials. Low sound velocity materials (such as Terfenol-D), or increase the vibration mass of the main vibration area of the shell to achieve.

The patent No. CN 105702244 A is an embedded external drive type IV flexural transducer. In order to change the traditional internal longitudinal drive to the external longitudinal drive structure, the drive stack enters the inside of the shell through the embedded structure of the shell. And the driving form is external driving, which reasonably reduces the external structure size of the transducer.

Compared with the external drive structure proposed in the above-mentioned patents, the present invention differs in that the conformal drive type IV flextensional transducer in the present invention adopts a new drive structure conformal to the flextensional shell. It is to realize the lower operating frequency characteristics of the transducer, and both the realization principle and the structure are completely different.

Contents of the invention

Aiming at the deficiencies in the current prior art, the present invention aims to provide a method to solve the problem of further reducing the resonance frequency of Type IV flexural transducers with the same structural size, making it easier for Type IV flexural transducers to achieve low frequency, small Dimensional properties of conformally driven type IV flextensional transducers.

The purpose of the present invention is achieved like this:

The present invention is a conformal drive type IV flextensional transducer, including a flextensional housing 1, a ceramic arc 2, a rubber pad 3, an upper cover plate 4, a lower cover plate 5, a screw rod 6, a nut 7, and an electrical connection. The watertight cable head 8 is characterized in that: the flexural shell 1 is a stretched ellipse structure with an internal inlay opening 9, the upper and lower end faces are connected to the rubber pad 3, and the upper and lower surfaces of the rubber pad 3 are respectively connected to the upper cover plate 4. The lower cover plate 5 is in close contact; the upper cover plate 4 and the lower cover plate 5 are distributed with through holes 10, the screw rod 6 is connected to the upper cover plate 4 and the lower cover plate 5, and is tightened with the nut 7 to form a conformal drive The overall external structure of the flextensional transducer; the upper cover plate 4 is provided with an electrical connection hole 11, and the electrical connection hole 11 is provided with a watertight cable head 8, and the watertight cable head 8 is electrically connected in parallel with two ceramic arcs 2 through a wire .

The outline structure of the outer surface of the flextensional shell 1 is elliptical, and there are two symmetrical internal inlay openings 9 on the inner side of the short axis of the flextensional shell 1; 2. The radius of curvature of the outer edge surface is consistent;

The two sides of the screw rod 6 are respectively provided with steps with a limit function.

The ceramic arc 2 is a radially polarized ceramic arc or an inlaid ceramic arc.

The radially polarized ceramic arc is part of the structure of the PZT-4 ceramic ring; the radially polarized ceramic arc ring has de-electrode treatment on the inside and outside of the edge

The inlaid ceramic arc is an arc spliced by n wedge-shaped PZT-4 piezoelectric ceramic strips, where n is an even number; the piezoelectric ceramic strips are polarized along the thickness direction, and every two adjacent piezoelectric ceramic strips The polarization directions are opposite; parallel-connected electrode sheets are arranged between two adjacent ceramic strips; two metal strips 13 are arranged at the outermost edge of the circle; the outer surface of the inlaid ceramic arc is an epoxy resin glued glass silk layer 12 .

Compared with the prior art, the present invention has the beneficial effects of:

The present invention overcomes the shortcomings of the IV-type bending-tension transducer with the traditional drive structure that the vibrating frequency of the transducer shell is significantly increased due to the long beam drive form, and adopts a ceramic arc drive and a shell structure with an arc inlaid opening. , to realize the conformal driving form of the ceramic and the shell, and under the premise of ensuring that the bending vibration frequency of the shell does not increase significantly, the displacement amplification effect of the flextensional transducer can be reasonably used, so as to further reduce the vibration of the flextensional transducer Operating frequency, and has the characteristics of higher power operation. The patented underwater acoustic transducer has the characteristics of small size, low frequency, high power, and light weight. It can be used alone or in an array for active detection sonar equipped with various small platforms, deep sea acoustic communication and other fields.

Description of drawings

Fig. 1 is a schematic cross-sectional view of the structure of a conformal drive Type IV flextensional transducer.

Fig. 2 is a schematic diagram of the structure of a conformal drive Type IV flextensional transducer.

Fig. 3 is a schematic diagram of the shell structure of a conformal drive type IV flextensional transducer.

Fig. 4 is a schematic diagram of a radially polarized ceramic arc structure of a conformally driven Type IV flextensional transducer.

Fig. 5 is a schematic diagram of a ceramic circular arc inlaid with a conformal drive Type IV flexural transducer.

detailed description

The present invention is described in detail below in conjunction with accompanying drawing:

As shown in Figures 1 to 2, the conformal drive type IV flextensional transducer of the present invention mainly includes a flextensional housing 1, two ceramic arcs 2, two rubber pads 3, an upper cover plate 4, a lower Cover plate 5, six connecting screw rods 6, six nuts 7, watertight cable head 8. The flexural shell 1 has two internal inlay openings 9, which are respectively matched and connected with two ceramic arcs 2 to achieve conformal shape. The upper and lower surfaces of the flexural shell 1 are respectively connected with the rubber pad 3, and the remaining two sides of the rubber pad are connected with the upper cover plate. 4 is connected with the lower cover plate 5, there are through holes 10 distributed on the upper and lower cover plates, the connecting screw 6 is connected with the upper and lower cover plates 5, and the nut 7 is used to tighten it to form the overall external structure of the transducer, and apply preload to the rubber pad force to achieve watertightness. The upper cover plate 4 has an electrical connection hole 11 which is connected with the watertight cable head 8, and the watertight cable head 8 is electrically connected in parallel with the two ceramic arcs 2 through wires.

As shown in Figure 3, the flexural shell 1 of the present invention is made of aluminum alloy (or titanium alloy) metal material through processing, and it is a tensile body structure, and the outer surface contour is an elliptical structure form, and the inner surface is opened. The two internal inlay openings 9 have an elliptical structure, the internal inlay openings 9 are circular arc sections at a certain angle, and the two internal inlay openings 9 are symmetrically distributed inside the short axis of the flextensile shell 1;

The ceramic arc 2 of the present invention can be a radially polarized arc, or an inlaid ceramic arc. The radially polarized ceramic arc is shown in Figure 4, and the inner and outer edges of the arc are de-electroded to prevent electrical short circuit when in contact with the shell; the inlaid ceramic arc is shown in Figure 5, which is composed of n pieces ( n is determined by the arc angle, radius and wedge size, where n must be an even number) The wedge-shaped PZT-4 piezoelectric ceramic strips are bonded to form an arc at a certain angle, and the piezoelectric ceramic strips are polarized along the ring to the thickness direction, and each phase The polarization directions of the two adjacent piezoelectric ceramic strips are opposite, and the electrode sheets are arranged between the ceramic strips, which are connected in parallel on the circuit. There are two metal strips 13 on the outermost edge of the ring to ensure sufficient strength when assembling with the shell. It is convenient for assembly; and an epoxy resin glue glass thread layer 12 is pasted and glued on the outer side of the mosaic ceramic arc, which is used to realize electrical insulation and increase the structural strength of the ceramic arc 2 when in contact with the shell. The watertight cable head 8 is connected with the electrical connection hole 11, and the watertightness is guaranteed by the rubber pad 3, and the positive and negative electrodes of the ceramic arc 2 are drawn out with a wire to connect with the watertight cable head 8.

The flextensional shell 1 and the ceramic arc 2 described above are characterized in that the outer surface of the ceramic arc 2 is the same as the surface radius of curvature of the inlay opening 9 inside the flextensional shell, and the opening angle of the ceramic arc 2 is Larger than the opening angle of the inner inlaid opening 9, while achieving tight fit in the radial direction, the shell exerts sufficient prestress on the ceramic arc in the circumferential direction to achieve high-power work.

The rubber pad 3 is made of silicone rubber or fluororubber with a certain hardness and water resistance. The surface of the upper cover plate 4 and the lower cover plate 5 are in sufficient contact to achieve a certain degree of decoupling in the height direction in addition to the basic watertight characteristics;

The upper cover plate 4 and the lower cover plate 5 have the same structural size and are made of aluminum alloy (or titanium alloy) metal material. Connection; the upper cover plate 4 has an electrical connection hole 11 for installing a watertight cable head 8 for electrical connection;

The connecting screw 6 is made of stainless steel (or titanium alloy) metal material, and has steps with limiting functions on both sides. During the assembly of the upper cover 4 and the lower cover 5, the two limiting steps pass through the nut 7 Tighten the compressed rubber pad 3 and set the maximum stroke of the compressed rubber pad 3, so that the rubber pad 3 is within the elastic range and can realize the watertight sealing function, and at the same time ensure the overall strength of the transducer and the maximum working water depth.

When the transducer of the present invention works in water, an alternating electric field is applied to two ceramic arcs 2 electrically connected in parallel, and under the excitation of the alternating electric field, the ceramic arcs 2 generate circular reciprocating vibrations, thereby exciting bending tension The respiration vibration mode of the housing 1 has a larger reciprocating vibration displacement at the short axis of the housing due to the displacement amplification effect, so as to realize sound radiation. Because the present invention adopts the conformal structural form of the ceramic arc 2 and the flextensional shell 1, the structural rigidity of the flextensional shell 1 changes little, and in the case of the basic breathing vibration mode, the transducer is realized. Lower frequency radiation characteristics. The conformal driving form provides a new method for further realizing the low-frequency and small-size characteristics of the flextensional transducer.

The above embodiments are only used to illustrate the technical solution of the present invention and not to limit. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that, without departing from the protection of the claims of the present invention, other implementations of the present invention should be included in the scope of the claims of the present invention.

Claims (6)

1. conformal driving IV type flextensional transducers, including flextensional shell (1), ceramic circular arc (2), rubber blanket (3), upper cover plate (4), Lower cover (5), screw rod (6), nut (7) and watertight cable head (8), it is characterised in that：Described flextensional shell (1) is short axle Inner side is provided with two symmetrical internal stretching oval structures for inlaying mouth (9), and upper and lower end face is connected with rubber blanket (3), rubber blanket (3) upper and lower surface is in close contact with upper cover plate (4), lower cover (5) respectively；It is distributed with upper cover plate (4), lower cover (5) logical Hole (10), screw rod (6) connection upper cover plate (4), lower cover (5), is screwed with nut (7), constitutes conformal driving flextensional transducer Overall external structure；Upper cover plate (4) is provided with electrical connection hole (11), electrical connection hole (11) and is provided with watertight cable head (8), watertight End (8) carries out parallel connection by wire and two ceramic circular arcs (2) and electrically connected.

2. conformal driving IV type flextensional transducers according to claim 1, it is characterised in that：Inlay mouth in described inside (9) it is arc structure, its edge surface is consistent with ceramic circular arc (2) edge surface radius of curvature；Ceramic circular arc (2) angle of release angle is big The angle of release angle of mouth (9) is inlayed in inside.

3. conformal driving IV type flextensional transducers according to claim 1, it is characterised in that：Described screw rod (6) both sides It is respectively provided with the step of limit function.

4. conformal driving IV type flextensional transducers according to claim 2, it is characterised in that：Described ceramic circular arc (2) For radial polarised ceramic circular arc or mosaic ceramic circular arc.

5. conformal driving IV type flextensional transducers according to claim 4, it is characterised in that：Described radial polarised ceramics Circular arc is the part-structure of the ceramic annulus of PZT-4；Radial polarised ceramic circular arc ring edge interior outside has Electrode treatment.

6. conformal driving IV type flextensional transducers according to claim 4, it is characterised in that：Described mosaic ceramic circular arc It is the circular arc being spliced into by n pieces wedge shape PZT-4 piezoelectric ceramics bars, n is even number；Piezoelectric ceramics bar through-thickness polarizes, per phase Adjacent two panels piezoelectric ceramics bar polarised direction is opposite；The electrode slice being connected in parallel is set between adjacent two ceramic bars；Ring most side Edge has two panels bonding jumper (13)；Mosaic ceramic circular arc outer surface is epoxide-resin glue glass fiber layer (12).