阅读说明：本技术 一种超磁致伸缩材料换能器预紧方法与装置 (Method and device for pre-tightening giant magnetostrictive material transducer ) 是由 张建富 冯平法 周辉林 郁鼎文 吴志军 查慧婷 于 2019-11-25 设计创作，主要内容包括：本发明提供了一种超磁致伸缩材料换能器预紧装置及一种超磁致伸缩材料换能器预紧方法,针对于现有换能器当中超磁致伸缩材料的结构与预紧方式的特点,在进行换能器预紧过程中,容易由于预紧不当,导致超磁致伸缩材料受力不均匀,换能效率不高。预紧装置包括调节压块和调节螺栓,调节压块通过多个调节螺栓连接于超磁致伸缩材料换能器机壳,换能器当中的预紧力由两组调节螺栓交替提供,相邻两组调节螺栓交替拧紧时互相抵消由于力矩引起的摩擦力,从而使每个螺栓获得合理预紧力,进一步通过调节压块将压力传递至超磁致伸缩材料,保证超磁致伸缩材料换能器的换能效率,实现大功率输出。(The invention provides a device and a method for pre-tightening a giant magnetostrictive material transducer, aiming at the characteristics of the structure and the pre-tightening mode of the giant magnetostrictive material in the existing transducer, the giant magnetostrictive material is easy to be stressed unevenly and the transduction efficiency is not high due to improper pre-tightening in the pre-tightening process of the transducer. The pre-tightening device comprises an adjusting press block and adjusting bolts, the adjusting press block is connected to the shell of the giant magnetostrictive material transducer through the adjusting bolts, pre-tightening force in the middle of the transducer is provided by two groups of adjusting bolts in an alternating mode, and friction force caused by torque is offset when two adjacent groups of adjusting bolts are screwed up in an alternating mode, so that each bolt obtains reasonable pre-tightening force, pressure is further transmitted to the giant magnetostrictive material through the adjusting press block, the transduction efficiency of the giant magnetostrictive material transducer is guaranteed, and high-power output is achieved.)

1. The device for pre-tightening the giant magnetostrictive material transducer is characterized by comprising an adjusting pressing block and adjusting bolts, wherein the adjusting pressing block is connected to a shell of the giant magnetostrictive material transducer through the adjusting bolts and abuts against a giant magnetostrictive part in the giant magnetostrictive material transducer, and the adjusting bolts are used for providing pre-tightening force for the adjusting pressing block and transmitting the pre-tightening force to the giant magnetostrictive part; the adjusting press block is provided with mounting holes, the number of the mounting holes is more than four and even, the mounting holes are evenly distributed along the circumferential direction of the adjusting press block, and the number of the adjusting bolts is less than or equal to the number of the mounting holes.

2. The magnetostrictive material transducer pretensioning device according to claim 1, characterized in that the adjusting press block comprises a first part and a third part: the first portion is used for abutting against the giant magnetostrictive portion, and the third portion is used for installing the adjusting bolt.

3. The pre-tensioning device for the giant magnetostrictive material transducer according to claim 2, wherein the adjusting press block further comprises a second part which abuts against the housing and can slide along the housing.

4. The pre-tensioning device for the giant magnetostrictive material transducer according to any one of claims 1 to 3, characterized in that the projection of the casing along the direction of the center line of the giant magnetostrictive material transducer covers the projection of the adjusting pressure block along the direction.

5. The pre-tightening device for the giant magnetostrictive material transducer according to any one of claims 1 to 3, characterized in that a mounting structure is arranged in the housing, and after an excitation part in the giant magnetostrictive material transducer is fixed to the housing through the mounting structure, projections of the excitation part and the giant magnetostrictive part are overlapped in a direction perpendicular to a central line of the giant magnetostrictive material transducer.

6. The pre-tightening device for the giant magnetostrictive material transducer according to any one of claims 1 to 3, characterized in that the adjusting press block is provided with a threading hole for threading cables of the excitation part and external equipment.

7. A method for pre-tightening a giant magnetostrictive material transducer, which is characterized by comprising the device for pre-tightening the giant magnetostrictive material transducer as claimed in any one of claims 1 to 6, wherein a first group of adjusting bolts and a second group of adjusting bolts are uniformly arranged along the circumferential direction of an adjusting pressing block, the number of mounting holes for mounting the adjusting bolts is 2n, and n is a natural number greater than 2, and the method comprises the following steps:

s10, according to the needed pretightening force F of the giant magnetostrictive material transducer_ADetermining the number of the adjusting bolts so that the sum of the maximum pretightening force of all the adjusting bolts is larger than F_A；

S30, mounting a first group of adjusting bolts, wherein m is total, m is less than or equal to n, and increasing the pretightening force F of each adjusting bolt in the first group of adjusting bolts₁To a preset value F₀₁；

S40, mounting a second group of adjusting bolts, wherein k is the total number of adjusting bolts, k is equal to m, and increasing the pretightening force F of a single adjusting bolt in the second group of adjusting bolts₂To a preset value F₀₂；

S50, alternately adjusting the pretightening force F₁And F₂Until the pre-tightening force F of the bolt is adjusted₁、F₂Is equal to a preset value F₀₀。

8. The method for pretensioning a giant magnetostrictive material transducer according to claim 7, further comprising, after step S50:

and S51, performing impedance analysis on the giant magnetostrictive material transducer, and adjusting the pretightening force of a part of adjusting bolts according to the analysis result so that the impedance analysis result is the same as or similar to the optimal impedance circle.

9. The method for pretensioning a giant magnetostrictive material transducer according to claim 7, further comprising, after step S50:

s52, taking out part of the adjusting bolts to ensure that the sum of the residual adjusting bolt pretightening force is equal to the pretightening force F required by the giant magnetostrictive material transducer_AAnd the rest adjusting bolts are uniformly distributed along the circumferential direction of the adjusting pressing block.

10. The method of pretensioning a giant magnetostrictive material transducer according to any of claims 7-9, characterized in that the first and second sets of adjusting bolts each tighten each bolt in sequence in clockwise/counterclockwise direction.

Technical Field

The invention relates to the technical field of ultrasonic processing, in particular to a pre-tightening device and a pre-tightening method for a giant magnetostrictive material transducer.

Background

In recent years, due to the characteristics of high energy density, large magnetostriction coefficient, high response speed and the like, the giant magnetostrictive material has gained attention in the research field of ultrasonic transducers, particularly in the field of high-power rotary ultrasonic processing. Giant magnetostrictive materials are also desirable as miniaturized transducer designs because they can achieve greater power at smaller dimensions. With the appearance of multi-mode ultrasonic vibration such as elliptical ultrasonic machining, the effective utilization and reasonable design of the energy of the giant magnetostrictive material transducer become hot points for research.

According to related researches, the vibration characteristic of the giant magnetostrictive material transducer is greatly influenced by the pre-tightening force, and the vibration characteristic of the transducer is obviously influenced by the pre-tightening force acting on the giant magnetostrictive material. Due to the characteristics of the structure and the pre-tightening mode of the giant magnetostrictive material, the giant magnetostrictive material is easily stressed unevenly due to improper pre-tightening in the pre-tightening process of the transducer, the energy conversion efficiency of the transducer is not high, and the stability and the amplitude of the output amplitude are influenced.

Therefore, in order to ensure the effective pre-tightening of the giant magnetostrictive material transducer and improve the transduction efficiency of the transducer, the pre-tightening method and the device for the giant magnetostrictive material transducer have important significance.

Disclosure of Invention

Therefore, it is necessary to provide a device and a method for pre-tensioning a giant magnetostrictive material transducer, aiming at the problem of improper pre-tensioning of the current giant magnetostrictive material transducer.

The above purpose is realized by the following technical scheme:

a pre-tightening device for a giant magnetostrictive material transducer comprises an adjusting press block and adjusting bolts, wherein the adjusting press block is connected to a shell of the giant magnetostrictive material transducer through a plurality of adjusting bolts and abuts against a giant magnetostrictive part in the giant magnetostrictive material transducer, and the adjusting bolts are used for providing pre-tightening force for the adjusting press block and transmitting the pre-tightening force to the giant magnetostrictive part; the adjusting press block is provided with mounting holes, the number of the mounting holes is more than four and even, the mounting holes are evenly distributed along the circumferential direction of the adjusting press block, and the number of the adjusting bolts is less than or equal to the number of the mounting holes.

In one embodiment, the conditioning compact comprises a first portion and a third portion: the first portion is used for abutting against the giant magnetostrictive portion, and the third portion is used for installing the adjusting bolt.

In one embodiment, the adjusting pressing block further comprises a second portion abutting against the housing and slidable along the housing.

In one embodiment, the projection of the casing along the direction of the center line of the giant magnetostrictive material transducer covers the projection of the adjusting compact along the direction.

In one embodiment, a mounting structure is arranged in the casing, and after an excitation part in the giant magnetostrictive material transducer is fixed to the casing through the mounting structure, projections of the excitation part and the giant magnetostrictive material transducer in a direction perpendicular to a central line of the giant magnetostrictive material transducer are overlapped.

In one embodiment, the adjusting pressing block is provided with a threading hole for threading the cable of the excitation part and the external equipment.

The invention also provides a method for pre-tightening the giant magnetostrictive material transducer, which comprises the device for pre-tightening the giant magnetostrictive material transducer, wherein the first group of adjusting bolts and the second group of adjusting bolts are uniformly arranged along the circumferential direction of the adjusting pressing block, the number of mounting holes for mounting the adjusting bolts is 2n, n is a natural number greater than 2, and the method comprises the following steps:

s10, according to the needed pretightening force F of the giant magnetostrictive material transducer_ADetermining the number of the adjusting bolts so that the sum of the maximum pretightening force of all the adjusting bolts is larger than F_A；

S30, installing the firstM adjusting bolts are arranged in group, m is less than or equal to n, and the pretightening force F of a single adjusting bolt in the first group of adjusting bolts is increased₁To a preset value F₀₁；

S40, mounting a second group of adjusting bolts, wherein k is the total number of adjusting bolts, k is equal to m, and increasing the pretightening force F of a single adjusting bolt in the second group of adjusting bolts₂To a preset value F₀₂；

S50, alternately adjusting the pretightening force F₁And F₂Until the pre-tightening force F of the bolt is adjusted₁、F₂Is equal to a preset value F₀₀。

In one embodiment, step S50 is followed by:

and S51, performing impedance analysis on the giant magnetostrictive material transducer, and adjusting the pretightening force of a part of adjusting bolts according to the analysis result so that the impedance analysis result is the same as or similar to the optimal impedance circle.

In one embodiment, step S50 is followed by:

s52, taking out part of the adjusting bolts to ensure that the sum of the residual adjusting bolt pretightening force is equal to the pretightening force F required by the giant magnetostrictive material transducer_AAnd the rest adjusting bolts are uniformly distributed along the circumferential direction of the adjusting pressing block.

In one embodiment, the first set of adjusting bolts and the second set of adjusting bolts each tighten each bolt in sequence in a clockwise/counterclockwise direction.

The invention has the beneficial effects that:

the invention provides a device and a method for pre-tightening a giant magnetostrictive material transducer. In the existing transducer, a pre-tightening force is provided by using connecting pieces such as bolts and the like, and is transmitted to a giant magnetostrictive material through an adjusting pressing block; because the vibration characteristic of the giant magnetostrictive material is greatly influenced by the pretightening force, the single bolt is influenced by the mounting structure and deformation, so that improper pretightening is easily caused, the giant magnetostrictive material is unevenly stressed, and the energy conversion efficiency is not high. According to the pre-tightening device and the pre-tightening method provided by the invention, the adjusting bolts for providing the pre-tightening force are divided into two groups, and the two groups of bolts mutually counteract the friction force caused by the torque when being alternately tightened, so that each bolt obtains a reasonable pre-tightening force, and further, the pressure is transmitted to the giant magnetostrictive material through the adjusting press block, so that the transduction efficiency of the giant magnetostrictive material transducer is ensured, and the high-power output is realized.

Drawings

FIG. 1 is a schematic structural diagram of an adjusting pressure block in a pre-tensioning device of a giant magnetostrictive material transducer according to an embodiment of the present invention

FIG. 2 is a schematic structural diagram of a giant magnetostrictive material transducer according to an embodiment of the invention;

FIG. 3 is a perspective view of the giant magnetostrictive material transducer of FIG. 2;

FIG. 4 is a schematic diagram of deformation of a single adjusting bolt before and after being subjected to a pre-tightening force;

FIG. 5 is a schematic diagram of the pressure block after being subjected to pretightening force;

FIG. 6 is a schematic illustration of the tilt of a single adjusting bolt after being subjected to a moment;

FIG. 7 is a schematic view of the force applied by a plurality of adjusting bolts after forming a "three-bolt halving" structure;

FIG. 8 is an analysis graph of the actual pretension of the first and second sets of adjusting bolts.

Wherein:

a conditioning compact 110; a first portion 111; a second portion 112; a third portion 113; a threading hole 114; a giant magnetostrictive portion 120; an excitation section 130; a horn 140; a cutting portion 150; a housing 160; a fixing portion 161; a moving portion 162; the bolt 170 is adjusted.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below by way of embodiments with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The numbering of the components themselves, such as "first", "second", etc., is used herein only to distinguish between the objects depicted and not to have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings). In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

The invention provides a pre-tightening device and a pre-tightening method for a giant magnetostrictive material transducer, aiming at the problem that bolt holes for mounting bolts in a pre-tightening structure are deformed and the bolts cannot be screwed continuously without large pre-tightening force due to overlarge pre-tightening force applied to the bolts for providing the pre-tightening force in the conventional transducer, particularly a miniaturized transducer, the pre-tightening force in the transducer is provided by two groups of adjusting bolts alternately, and the deformation of the bolt holes caused by the pre-tightening force can be counteracted mutually when two adjacent adjusting bolts are screwed alternately, so that a single bolt can obtain large pre-tightening force, the giant magnetostrictive material is enabled to be acted by the large pre-tightening force, and high-power output is realized.

Specifically, as shown in fig. 2 and 3, the giant magnetostrictive material transducer includes a giant magnetostrictive material transducer pre-tightening device composed of an adjusting compact 110 and adjusting bolts 170, a giant magnetostrictive portion 120, an excitation portion 130, an amplitude transformer 140, a cutting portion 150 and a casing 160, the adjusting compact 110 is connected to the casing 160 through a plurality of adjusting bolts 170 and abuts against the giant magnetostrictive portion 120, the casing 160 includes a moving portion 162 close to an axis of the giant magnetostrictive material transducer and a fixing portion 161 far away from the axis, and a connecting portion between the moving portion 162 and the fixing portion 161 has a relatively small thickness, so that the moving portion 162 vibrates in a minute amplitude relative to the fixing portion 161. The giant magnetostrictive part 120 deforms under the action of the excitation part 130, and the deformation of the giant magnetostrictive part 120 is transmitted to the cutting part 150 through the motion part 162 and the amplitude transformer 140; the number of the mounting holes on the adjusting pressing block 110 is more than four and is even, the mounting holes are evenly distributed along the circumferential direction of the adjusting pressing block 110, the number of the adjusting bolts 170 is not more than the number of the mounting holes, and the adjusting pressing block 110 is connected with the fixing part 161 through the adjusting bolts 170. The adjusting press block 110 is positioned through the fixing part 161, the amplitude transformer 140 is positioned through the moving part 162, the fixing part 161 and the moving part 162 are integrated parts, the relative position relation between the fixing part 161 and the moving part 162 is easy to guarantee, and the movement precision of the giant magnetostrictive material transducer can be further improved.

When the giant magnetostrictive material transducer is gradually reduced, the size of the corresponding connecting piece for connecting each part is reduced due to the reduction of the whole size, and if the connecting piece is not adaptively adjusted, the problem of overlarge stress of individual connecting pieces can occur. The adjusting bolts 170 are distributed along the circumferential direction to form bolt groups, the pretightening force of the adjusting pressing block 110 is gradually increased according to a certain sequence, and the problem that the adjusting pressing block 110 is deformed or a certain bolt fails due to overlarge pretightening force of the certain bolt can be solved.

In one embodiment, as shown in fig. 1, the adjusting pressing block 110 includes a first portion 111, a second portion 112 and a third portion 113 with gradually increasing sizes, and after installation, the first portion 111, the second portion 112 and the third portion 113 have gradually increasing distances from the giant magnetostrictive portion 120, and the first portion 111 is used for abutting against the giant magnetostrictive portion 120 and providing a pre-tightening force to the giant magnetostrictive portion 120; the second portion 112 is used for abutting against the casing 160, generally, the shape of the second portion 112 matches the shape of the inner surface of the casing 160, and the two portions can be mutually connected, so that the casing 160 guides the adjusting pressing block 110 and ensures that the adjusting pressing block 110 cannot be greatly deformed and rotated; the third portion 113 is provided with a plurality of mounting holes for mounting the adjusting bolts 170. Since the adjusting press block 110 is used as a conducting member for the preload, the first portion 111, the second portion 112 and the third portion 113 are integrated, so that the preload can be well transmitted from the housing 160 to the super magnetostrictive portion 120 through the adjusting bolt 170.

In one embodiment, because the entire giant magnetostrictive material transducer is installed inside the cavity of the tool holder and other components, and the housing 160 of the giant magnetostrictive material transducer needs to be abutted against the surface of the cavity to ensure accuracy, in order to avoid friction or motion interference between the adjusting pressing block 110 and the surface of the cavity, the maximum dimension (usually, the third portion 113) of the adjusting pressing block 110 in the direction perpendicular to the center line of the giant magnetostrictive material transducer is designed to be smaller than or equal to the dimension of the housing 160 in the direction so as to avoid rotation of the adjusting pressing block 110 caused by motion interference, and the force transmission of the adjusting pressing block 110 is influenced.

In one embodiment, a mounting structure is provided on the chassis 160 for controlling the position of the exciting portion 130. Since the deformation of the giant magnetostrictive part 120 depends entirely on the excitation of the excitation part 130, the excitation circuit formed by the excitation part 130 needs to have the same plane of symmetry as the giant magnetostrictive part 120. The mounting structure can control the position of the excitation part 130 along the central line direction of the giant magnetostrictive material transducer, and the side surface of the excitation part 130 abuts against the inner surface of the casing 160 to control the position of the excitation part 130 along the direction perpendicular to the central line direction of the giant magnetostrictive material transducer.

In one embodiment, in order to facilitate connection between the excitation part 130 and other elements requiring external electrical connection in the giant magnetostrictive material transducer, the adjusting press block 110 is provided with a threading hole 114, the diameter of the threading hole 114 should be larger than the sum of the diameters of all cables passing through the threading hole 114, and both ends of the threading hole 114 should be chamfered to avoid damage to the cables.

In one embodiment, the joint of first portion 111 and second portion 112 of adjusting compact 110 is chamfered to reduce the stress concentration effect at the joint of first portion 111 and second portion 112. The end surface of the second portion 112 is chamfered to facilitate installation of the adjustment block 110 into the housing 160. The junction of the second portion 112 and the third portion 113 is chamfered to prevent the third portion 113 from being deformed greatly when being pre-tensioned by the adjusting bolt 170.

Based on the giant magnetostrictive material transducer, the invention also provides a pre-tightening method of the giant magnetostrictive material transducer, which comprises the steps of dividing the adjusting bolts into two groups, and alternately adjusting the pre-tightening force of the two groups of adjusting bolts so as to achieve the purpose of realizing large pre-tightening force through small bolts and simultaneously avoid the problems of deflection and difficult adjustment of an adjusting press block caused by overlarge stress of a single adjusting bolt.

For ease of understanding, the pre-tensioning process of the giant magnetostrictive material transducer is described. The stress and deformation before and after the single adjusting bolt is pre-tightened are shown in figure 4, F' represents the pre-tightening force applied to the single adjusting bolt, L represents the length of the adjusting bolt before the adjusting bolt is not pre-tightened, and delta₁The length elongation after the adjusting bolt is pre-tightened is shown, when F' is smaller, the adjusting pressing block is regarded as rigid body displacement, delta₂FIG. 5 is a schematic diagram showing the displacement of the adjusting press block after the adjusting press block is pre-tightened, Fn shows the reaction force of the giant magnetostrictive part on the adjusting press block, M shows the moment action on the adjusting press block, and the direction is shown in FIG. 5. when F' is too large, the influence of the moment M on the adjusting press block is not negligible, and the too large moment will cause the adjusting bolt to incline relative to the bolt hole on the casing, as shown in FIG. 6, the inclination angle is α. at this time, the friction force generated between the adjusting bolt and the inner wall of the bolt hole of the casing due to the bending moment M hinders the adjusting bolt from continuing screwing in, and the large pre-tightening force cannot be achieved and the pre-tightening is effective.

In order to reduce the influence of bending moment M on pre-tightening, the pre-tightening method of the giant magnetostrictive material transducer provided by the invention divides the adjusting bolts into two groups, and alternately adjusts the two groups to improve the influence of the bending moment M, and specifically comprises the following steps:

s10, according to the needed pretightening force F of the giant magnetostrictive material transducer_ADetermining the number of the adjusting bolts so that the sum of the maximum pretightening force of all the adjusting bolts is larger than F_A；

S30, mounting a first group of adjusting bolts, wherein m is total, m is less than or equal to n, and increasing the pretightening force F of each adjusting bolt in the first group of adjusting bolts₁To a preset value F₀₁；

S40, mounting a second group of adjusting bolts, wherein k is the total number of adjusting bolts, k is equal to m, and increasing the pretightening force F of a single adjusting bolt in the second group of adjusting bolts₂To a preset value F₀₂；

S50, alternately adjusting the pretightening force F₁And F₂Until the pretightening force F of all the adjusting bolts₁、F₂Is equal to a preset value F₀₀；

The number of the mounting holes for mounting the adjusting bolts on the adjusting press block is 2n, n is a natural number larger than 2, the first group of adjusting bolts and the second group of adjusting bolts are uniformly arranged along the axial direction of the adjusting press block, the distance between any two adjacent adjusting bolts in the same group is equal, and the distance between any two adjacent adjusting bolts in different groups is equal.

Specifically, for the stress situation of the "three-bolt halving" structure, please refer to fig. 7 and 8, wherein F in fig. 7₁' represents a single first groupAdjusting the pre-tightening force to which the bolt is subjected, F₂' represents the preload to which a single second set of adjusting bolts is subjected, △ delta₁Showing the bolt length extension of a single first set of adjustment bolts, as seen in FIG. 8, as △ δ₁Increase, F₁' taper down, F₂' gradually increase, and when △ delta₁＝0.5δ₁When F is present₁'＝F₂'-0.5F'. Through increasing the alternating reciprocating pretightening force of the first group of adjusting bolts and the second group of adjusting bolts, the negative influence caused by friction torque can be effectively improved, and large pretightening force is obtained.

Further, step S50 is followed by: and S51, performing impedance analysis on the giant magnetostrictive material transducer, and adjusting the pretightening force of a part of adjusting bolts according to the analysis result so that the impedance analysis result is the same as or similar to the optimal impedance circle. . When all the adjusting bolts are screwed in place, the sum of the pretightening forces is equal to a preset value F₀₀In time, the stress conditions of the adjusting bolts can be guaranteed to be consistent by tools such as a torque measuring wrench. However, even if the stress conditions of the plurality of adjusting bolts are consistent, the direction of the pressing force finally applied to the giant magnetostrictive part by the adjusting press block is not necessarily the same as the ideal direction due to the influence of error factors such as machining errors and deformation, and an error angle may exist. In order to overcome the error angle, the adjusting bolt can be finely adjusted for multiple times, and the impedance analyzer is combined to perform comparative analysis on the impedance circle characteristics of the giant magnetostrictive material transducer to determine the optimal impedance circle.

In one embodiment, step S50 is followed by: s52, taking out part of the adjusting bolts to ensure that the sum of the residual adjusting bolt pretightening force is equal to the pretightening force F required by the giant magnetostrictive material transducer_AAnd the rest adjusting bolts are uniformly distributed along the circumferential direction of the adjusting pressing block. When a single bolt is screwed down, the bolt is influenced by the bending moment, and the achieved pretightening force is smaller than the maximum pretightening force which can be achieved when the bolt is not influenced by the bending moment. In order to enable the single adjusting bolt to reach the maximum pretightening force, some auxiliary adjusting bolts are required to be introduced to eliminate the influence of bending moment, and the pretightening force provided by all the adjusting bolts is basically consistent, so that the pretightening force of all the adjusting bolts is the sameThe sum of the tightening forces reaches a preset value F₀₀When F is present₀₀The pretension value required for adjusting the pressure piece is exceeded. In order to reduce the weight of the giant magnetostrictive material transducer, the auxiliary bolt for eliminating the moment influence can be removed, so that the sum of the pretightening force provided by the rest adjusting bolts is equal to the pretightening force actually required by the adjusting press block.

In the above embodiment, the first set of adjusting bolts and the second set of adjusting bolts are installed sequentially in a clockwise or counterclockwise direction to further eliminate the hindrance of the moment M to the pretension of the adjusting bolts.

Compared with the prior art, the giant magnetostrictive material transducer and the pretensioning method of the giant magnetostrictive material transducer provided by the invention at least have the following advantages:

1. the giant magnetostrictive material transducer is developing towards the direction of miniaturization design, and the giant magnetostrictive material transducer and the pretensioning method of the giant magnetostrictive material transducer provided by the invention can effectively realize large pretensioning force of a small bolt, ensure that the giant magnetostrictive material is acted by the large pretensioning force and realize high-power amplitude output;

2. the giant magnetostrictive material transducer and the pre-tightening method of the giant magnetostrictive material transducer can flexibly adjust the stress condition of the end face of the giant magnetostrictive material, correct the impedance circle characteristic on the premise of ensuring large pre-tightening force, and improve the stress uniformity and the vibration characteristic;

3. according to the selected multi-bolt pre-tightening structure, the preparation and reprocessing processes of the giant magnetostrictive material can be analyzed and researched reversely, and the influence rule of the stress uniformity on the vibration characteristic of the giant magnetostrictive material transducer is explored;

4. the giant magnetostrictive material transducer can realize high-power amplitude output, can maximally eliminate the influence caused by the difference of the preparation and reprocessing process performances of the giant magnetostrictive material on the premise of large pretightening force, and optimizes the vibration output.