CN104226576A

CN104226576A - Back lining structural system for thickness mode vibration ultrasonic transducer

Info

Publication number: CN104226576A
Application number: CN201310249716.0A
Authority: CN
Inventors: 柯宜京
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-06-18
Filing date: 2013-06-18
Publication date: 2014-12-24

Abstract

The invention provides a back lining structural system for a thickness mode vibration ultrasonic transducer. The system is capable of guiding useless acoustic wave energy, which is produced by a piezoelectric member of the ultrasonic transducer and which is opposite to the reflecting wavefront transmission direction, to the specific absorption area and preventing the acoustic wave energy from returning to the piezoelectric member to produce noise. The traditional composite material back lining layer can be replaced with the structural system; the structural system has the advantages that the noise interference caused by reflection of the piezoelectric member and back lining interface is reduced, the material used for manufacturing a back lining structure is not limited by the high attenuation requirements and can match with the piezoelectric member to the utmost extent, so that the transmittance can be increased, and interfacial reflection interference can be reduced; material machined simply can be selected, and the machinability and machining accuracy are improved; the sensitivity of the ultrasonic instrument can be improved to the certain extent. The system is capable of adopting various hard materials including resin, metal and ceramic in a machined manner simply.

Description

A kind of back structure system for thickness mode vibration ultrasonic transducer

Art

The present invention relates to a kind of ultrasonic transducer be operated under thickness mode vibration mode for ultrasonic measurement instrument.

Background technology

Known, in the course of work of thickness mode vibration ultrasonic transducer, the ultrasonic wave that piezoelectrics two end faces produce in transducer can produce reflection between piezoelectrics and medium, can have an impact to hyperacoustic launch mass with the back wave launching contrary interface, the direction of propagation, corrugated, the consequence of this impact causes the sensitivity of ultrasonic measurement instrument and resolution to decline, thus make final measurement distortion.The solution commonly used for this problem is that the end face that piezoelectrics are contrary with transmit direction in ultrasonic transducer installs back sheet (also claim damping block, absorb block or backing) additional, to absorb each secondary reflection ripple through this end face, to reduce the impact of back wave on launch mass.See " ultrasonic handbook " that Feng Ruo edits, publishing house of Nanjing University, in October, 1999, the 164th page, the 326th page.Backing material conventional is at present mainly the composite that tungsten powder mixes with synthetic resin, and common prescription is shown in " ultrasonic handbook " that Feng Ruo edits, publishing house of Nanjing University, in October, 1999, the 165th page.The reason selecting above formula wishes that sound wave is farthest decayed in back sheet.The shortcoming one of above scheme is in order to satisfied decay needs, the general characteristic resistance value of back sheet and the characteristic impedance value difference of piezoelectrics are apart from larger, be difficult to carry out rational acoustic impedance coupling, cause still having the sound wave compared with macro-energy reflected from piezoelectrics end face thus make acoustic emission debase; Two are backings of composite is flexible, needs by mold processes, complex process and cannot secondary fine processing, thus is difficult to control accuracy, is unfavorable for producing in enormous quantities.

Summary of the invention

In order to overcome the shortcoming that composite backing impedance contrast is excessive, be difficult to coupling and complex process, the invention provides a kind of structural system, the matching properties between backing and piezoelectrics can be improved and facilitate traditional process for machining, thus improving the performance of thickness mode vibration ultrasonic transducer.

The technical solution adopted for the present invention to solve the technical problems forms a sound trap in decaying less hard back lining materials by structural design at one, and sound trap is made up of following five parts:

A. focus lens group: for narrowing acoustic beam and changing Acoustic Wave Propagation direction, prevent acoustic beam from occurring unnecessary reflection or scattering.

B. dispersing lens group (focus): for scattered sound waves, makes ejected wave major part energy be scattered to and is around convenient to absorb.

C. plane of reflection group: for changing acoustic wave propagation path.

D. narrow orifice district: for providing path for focused beam and stopping that dispersing acoustic beam returns.

E. uptake zone: for absorbing the acoustic wave energy being scattered set of lenses scattering, is formed by pinking array on backing base material.

The tiny wave beam of ground roll boil down to that the piezoelectrics of thickness mode work can be produced by the combination of above five parts also projects in a narrow orifice, thus sound wave is not returned in piezoelectrics in Multiple Scattering absorption process, because every secondary reflection all exists certain transmission loss, as long as so the abundant SATT that just can make of order of reflection arrives enough little intensity.

Beneficial effect one of the present invention is that sound wave is sent into specific uptake zone by scioptics group, thus significantly reduces the possibility that sound wave returns along original route, thus reduces the noise jamming that piezoelectrics and backing boundary reflection cause; Two is owing to there is special uptake zone, can not be limited by the requirement of high sound attenuation for the material making back structure body, thus maximum mating can be done with piezoelectrics, thus increase transmissivity and reduce boundary reflection interference; Three is because back lining materials range of choices increases, so can the comparatively simple material of Choice and process, improves machinability and machining accuracy; Four is because backing and piezoelectrics can better mate, so can the sensitivity of raising ultrasonic instrument to a certain degree.

Accompanying drawing explanation

The present invention is further illustrated below in conjunction with accompanying drawing and concrete real-time mode.

Fig. 1 is structural system fundamental diagram of the present invention.

Fig. 2 is that structural system of the present invention can realize sample and the signal of acoustic propagation path.

Fig. 3 is that structural system of the present invention can realize sample sizing specification.

Fig. 4 be structural system of the present invention other realized configuration example and acoustic propagation path signal.

Fig. 5 is that the monofocal face mirror of structural system of the present invention and narrow orifice can realize configuration example and the signal of acoustic propagation path.

Fig. 6 is that the Double sided mirror narrow orifice combination of structural system of the present invention can realize configuration example and the signal of acoustic propagation path.

Detailed description of the invention

The present invention is set forth further below in conjunction with accompanying drawing

As shown in Figure 1, whole architecture is made up of focus lens group, the plane of reflection, dispersing lens group, narrow orifice district and uptake zone five part structural system operation principle of the present invention.Fig. 1 is a kind of possible combination of structural system involved in the present invention, it projects into narrow orifice by particular course by the plane of reflection by the plane wave produced by piezoelectrics after focus lens group focuses on, absorbed by uptake zone by the major part after dispersing lens group (dispersing lens can not exist under specific circumstances, the substitute is the virtual dispersing lens formed at condenser lens focus place) scattering is covering of the fan ripple of the acoustic beam after narrow orifice.It should be noted that above combination is the one possibility configuration of system of the present invention, the sequencing that different configuration five part occurs can be different, even certain part may not occur (just there is not the plane of reflection in sample as described in Fig. 2, Fig. 3), but this does not affect the basic functional principle of structural system of the present invention.

Fig. 2 and Fig. 3 gives of structural system of the present invention can realize sample, the acoustic wave propagation path that the Dark grey arrow in Fig. 2 produces for piezoelectrics.Sound wave finally can enter uptake zone as seen from Figure 2, and is difficult to get back in piezoelectrics due to the existence of narrow orifice by the acoustic wave energy that uptake zone is excessive on a small quantity.What Fig. 3 provided is, and this can the concrete size marking of implementation.

Can implementation be the typical embodiment of one of structural system of the present invention shown in flow process and Fig. 2, Fig. 3 shown in Fig. 1, based on principle of the present invention, also have multiple configuration to can be used for practice, Fig. 4 gives other three kinds of attainable configuration schemes.In addition, for those skilled in the art, said structure system basis can realize the present invention by multiple configuration, but this change without creative work realization obviously should in the protection domain of claims of the present invention.

Claims

1., for a back structure system for thickness mode vibration ultrasonic transducer, it is characterized in that

A. be made up of focus lens group, the plane of reflection, dispersing lens group, narrow orifice district and uptake zone five part, each part forms not conducting effect in unison by different matched combined.

B. make the various combination of this five part that unwanted sound wave is caused specific region by structural design to be decayed, thus form a sound trap.

2. as right 1 require as described in method, it is characterized by the useless sound wave making piezoelectric patches in thickness mode vibration ultrasonic transducer be in reverse to sound emission direction by structural design and absorbed by sound trap, thus eliminate interference to reach, improve the object of sensor performance.

3. the back structure for thickness mode vibration ultrasonic transducer, it is characterized in that being made up of focus lens group, dispersing lens group, narrow orifice district and uptake zone four part, CONSTRUCTED SPECIFICATION is as shown in Figure of description 2,3, the useless sound wave that piezoelectric patches in thickness mode vibration ultrasonic transducer can be in reverse to sound emission direction is absorbed by sound trap, thus the object eliminated interference to reach, improve sensor performance.

4. the back structure for thickness mode vibration ultrasonic transducer, it is characterized in that being made up of focus lens group, dispersing lens group, narrow orifice district and uptake zone four part, CONSTRUCTED SPECIFICATION is as shown in Figure of description 4, the useless sound wave that piezoelectric patches in thickness mode vibration ultrasonic transducer can be in reverse to sound emission direction is absorbed by sound trap, thus the object eliminated interference to reach, improve sensor performance.

5. the back structure for thickness mode vibration ultrasonic transducer, it is characterized in that by focus lens group, the plane of reflection and uptake zone three part form, CONSTRUCTED SPECIFICATION is as shown in Figure of description 5, the useless sound wave that piezoelectric patches in thickness mode vibration ultrasonic transducer can be in reverse to sound emission direction is absorbed by sound trap, thus the object eliminated interference to reach, improve sensor performance.

6. the back structure for thickness mode vibration ultrasonic transducer, it is characterized in that being made up of focus lens group, the plane of reflection and uptake zone, narrow orifice district four part, CONSTRUCTED SPECIFICATION is as shown in Figure of description 6, the useless sound wave that piezoelectric patches in thickness mode vibration ultrasonic transducer can be in reverse to sound emission direction is absorbed by sound trap, thus the object eliminated interference to reach, improve sensor performance.