Low-rigidity prestress applying device for rare earth flextensional transducer and using method

Abstract

The invention provides a low-rigidity prestress applying device for a rare earth flextensional transducer and a using method, the low-rigidity prestress applying device comprises a plurality of flexible rope groups, a first lock catch, a second lock catch, an adjustable pushing mechanism and a rare earth driving rod, each flexible rope group comprises at least one first rope and at least one second rope; one end of at least one first rope in each flexible rope group is connected to the upper end cover of the rare earth driving rod, the other end of the first rope is a free end and extends towards the lower end cover, and one end of at least one second rope in each flexible rope group is connected to the lower end cover of the rare earth driving rod; the other end of the second rope is a free end and extends towards the upper end cover; the free end of the first rope and the free end of the second rope sequentially penetrate through the second lock catch, the adjustable propelling mechanism and the first lock catch.

Description

Technical Field

[0001] This invention relates to the field of transducer technology, and more specifically, to a device and method for applying low-stiffness prestress to rare earth tension transducers. Background Technology

[0002] In the field of low-frequency acoustic transducers, rare-earth bending transducers have become an important direction for current research and engineering applications due to their unique performance advantages. Compared with traditional piezoelectric bending transducers, the Terfenol-D material used in rare-earth bending transducers has a higher energy density and a larger coefficient of expansion, enabling them to achieve lower resonant frequencies and higher low-frequency sound source level emission under the same operating conditions. At the same time, it significantly reduces the overall weight of the transducer, improving its efficiency and applicability in low-frequency sound radiation.

[0003] However, in existing technologies, the prestressing loading method for rare-earth tension transducers mainly employs a rigid screw-based structure to apply a concentrated preload. While this method is structurally simple, its high equivalent stiffness increases the overall equivalent stiffness of the transducer system, leading to a higher resonant frequency and consequently reducing low-frequency radiation efficiency. This problem is particularly prominent in applications seeking even lower operating frequencies, becoming a major technical bottleneck limiting further performance improvements.

[0004] To address this, some technical solutions propose using the stress generated by the contraction or stretching deformation of the tension shell itself as the prestress applied to the Terfenol-D rare earth rod, in order to simplify the structure and reduce stiffness. However, this method also has obvious shortcomings: (1) The magnitude of the applied prestress is limited by the flexibility of the shell itself. Especially for transducers with lower operating frequencies, their flexible shells often cannot provide sufficient initial stress, making it difficult for Terfenol-D to operate at the optimal prestress point; (2) Once the shell structure is finalized, the magnitude of the prestress is difficult to adjust, the control precision is low, and it is not conducive to system optimization; (3) In application scenarios where the transducer operates at high power for a long time or is subjected to complex static pressure changes, the prestress provided by the shell is prone to change, affecting the performance stability of the transducer.

[0005] To address the aforementioned issues, some studies have introduced a combined wire rope tensioning structure (as disclosed in application number CN202023236096.1). This structure uses a combination of wire rope, connecting blocks, adjusting screws, and other components to form a flexible loading mechanism, and applies and adjusts the prestress by adjusting the stroke of the mechanism. However, this solution is mainly applied to the tensioning assembly of the wire rope and is not specifically designed for the large deformation, high-precision control, and low stiffness requirements of rare earth bending transducers. Therefore, its adaptability in transducer systems remains limited.

[0006] Therefore, there is an urgent need for a new type of prestressed loading scheme that is low-stiffness, adjustable, and highly stable, which can not only meet the requirements of rare earth bending and tension transducers for low-frequency and high-efficiency operation, but also solve the shortcomings of existing prestressed loading methods in terms of flexible control and long-term stability. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the purpose of this invention is to provide a device and method for applying low-stiffness prestress to rare earth tension transducers.

[0008] According to one aspect of the present invention, a low-stiffness prestressing device for a rare-earth bending transducer is characterized in that it comprises a plurality of flexible rope groups, a first locking buckle, a second locking buckle, an adjustable pushing mechanism, and a rare-earth driving rod. Each flexible rope group includes at least one first rope and a second rope. At least one first rope in each flexible rope group has one end connected to the upper end cap of the rare-earth driving rod, and the other end of the first rope is a free end extending toward the lower end cap. At least one second rope in each flexible rope group has one end connected to the lower end cap of the rare-earth driving rod, and the other end of the second rope is a free end extending toward the upper end cap. The free ends of the first rope and the second rope pass sequentially through the second locking buckle, the adjustable pushing mechanism, and the first locking buckle.

[0009] Preferably, the plurality of flexible rope groups are arranged circumferentially and evenly on the outside of the rare earth drive rod.

[0010] Preferably, both the first rope and the second rope are steel wire ropes.

[0011] Preferably, the adjustable propulsion mechanism includes an adjusting screw and an adjusting nut. The adjusting screw has a through hole along its length, and the adjusting nut is threaded onto the threaded portion of the adjusting screw. The free ends of the first rope and the second rope pass through the through hole of the adjusting screw, and the adjusting screw is positioned between the first latch and the second latch.

[0012] Preferably, the first latch and the second latch include a locking head and a locking screw, wherein the locking screw is detachably connected to the locking head.

[0013] Preferably, the locking head is made of stainless steel.

[0014] Preferably, the number of flexible rope groups is eight, and each flexible rope group includes a first rope and a second rope.

[0015] According to another aspect of the present invention, a method of using a low-stiffness prestressing device for a rare-earth bending transducer, employing the device described in claim 1, the method of use comprising: Step S1: Arrange the first rope and the second rope in a loop around the outside of the rare earth drive rod, connect the upper end cap of the rare earth drive rod to one end of the first rope, and connect the lower end cap of the rare earth drive rod to one end of the second rope. Step S2: Fit the adjusting nut onto the adjusting screw, and pass the other ends of the first rope and the second rope through the second buckle, the adjusting screw, and the first buckle in sequence. The adjusting screw is located between the first buckle and the second buckle, the first buckle is located on the side closer to the free ends of the first rope and the second rope, and the second buckle is located on the side away from the free ends of the first rope and the second rope. Step S3: Lock the first latch; Step S4: Rotate the adjusting nut to push the adjusting screw forward and move the first locking buckle, thereby tightening the first and second ropes; Step S5: Lock the second lock, release the first lock, and remove the first lock, adjusting screw, and adjusting nut from the first and second ropes; Step S6: Thread the first lock onto the first rope and the second rope, so that the first lock is against the back of the second lock, and lock the first lock.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention uses steel wire rope as the prestressing transfer medium. By adjusting the diameter, number of wire ropes, and tension, a controllable initial prestress is applied to the rare-earth drive rod. This method enables multi-parameter combination adjustment, significantly improving the resolution and control accuracy of the prestressing loading process. Compared with traditional screw loading methods, due to the smaller cross-sectional area of ​​the steel wire rope, this invention produces finer stress change steps under the same loading force, thereby achieving more precise prestress setting.

[0017] 2. Due to the low stiffness and flexibility of steel wire rope, the prestressed loading structure of this invention does not significantly increase the overall equivalent stiffness of the transducer system like a rigid screw. Experimental results show that, after adopting the scheme of this invention, the resonant frequency of the rare-earth bending transducer is reduced from approximately 650 Hz to approximately 550 Hz, indicating a significant improvement in low-frequency performance. The current response in the 400–650 Hz low-frequency range is also enhanced, verifying that the scheme of this invention can effectively reduce the resonant point and improve the low-frequency sound source radiation efficiency.

[0018] 3. This invention utilizes a combination of a "locking buckle + hollow screw + forward nut" to form an adjustable tensioning mechanism, achieving precise tightening of the wire rope. This mechanism generates thrust by rotating the forward nut, causing the locking buckle to move along the wire rope direction, thus gradually applying tension to the wire rope. The entire loading process avoids welding operations, relying on a purely mechanical locking structure to achieve safe and reliable force transmission, making it suitable for long-term use and repeated loading, and significantly reducing assembly difficulty.

[0019] 4. The wire rope, locking buckle, hollow screw, and nut involved in this invention are all standard parts, making them easy to procure and replace. Compared with traditional screw preload structures, there is no need to machine high-precision large-diameter threads or perform welding sealing treatment, thereby effectively reducing manufacturing costs and processing cycles. This structure can be directly embedded into existing transducer assembly processes, facilitating engineered mass production and maintenance.

[0020] 5. The wire rope exhibits excellent fatigue resistance, maintaining good mechanical stability even under conditions such as large-amplitude transducer operation and cyclical changes in seawater hydrostatic pressure. Since prestressing loading is independent of shell deformation, external pressure variations have minimal impact on prestress, ensuring the rare-earth rod remains within its optimal operating range for extended periods. Furthermore, the double-locking structure provides reliable mechanical self-locking, preventing prestress relaxation during use and improving the transducer's long-term stability.

[0021] 6. Since the core technology of this invention relies on wire ropes and mechanical tensioning mechanisms for prestressing, it has a wide range of applications. The material, quantity, distribution of the wire ropes, and the structural form of the tensioning mechanism can be adjusted according to requirements. Therefore, this method is not only applicable to rare earth bending transducers, but can also be extended to other magnetostrictive or piezoelectric transducers that require prestress control, which is conducive to forming a wider range of technical protection and diversified implementation methods. Attached Figure Description

[0022] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a diagram showing the configuration of the prestressing loading fixture; Figure 2 This is a schematic diagram of the prestressing loading process; Figure 3 This is a schematic diagram showing the completion of prestressing loading. Figure 4 Curves showing prestressed loading and related data; Figure 5 This is another curve for prestressed loading and related data; In the diagram, 1 is the first latch, 2 is the hollow screw, 3 is the forward nut, 4 is the second latch, 5 is the wire rope, and 6 is the rare earth drive rod. Detailed Implementation

[0023] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0024] A low-stiffness prestressing device for a rare-earth bending transducer includes multiple flexible rope groups, a first locking buckle, a second locking buckle, an adjustable tensioning mechanism, and a rare-earth driving rod. Each flexible rope group includes at least one first rope and at least one second rope. One end of the at least one first rope is fixedly connected to the upper end cap of the rare-earth driving rod, and the other end is a free end extending towards the lower end cap along the direction of the rare-earth driving rod. Correspondingly, one end of the at least one second rope is fixedly connected to the lower end cap of the rare-earth driving rod, and the other end is a free end extending towards the upper end cap. The free ends of the first and second ropes are sequentially threaded through the second locking buckle, the adjustable tensioning mechanism, and the first locking buckle, thereby forming a through-type flexible tensioning path structure, facilitating the application of the required prestress by adjusting the tensioning mechanism.

[0025] This device is designed based on the requirement for low-stress prestress loading in rare-earth bending transducers. By fixing one end of a flexible rope to the upper and lower end caps of the rare-earth drive rod, and allowing its free end to extend in opposite directions, it is then threaded between a locking buckle and an adjustable mechanism, forming a structural path of relative traction. The adjustable tensioning mechanism can be rotated and moved axially, thereby driving the free end to tighten or loosen, achieving precise adjustment of the tension of the first and second ropes. The entire system utilizes the tension difference of the flexible ropes, combined with the stress response of the rare-earth material itself during transducer operation, to achieve low-stress application of prestress, ensuring stable operation of the device under high sensitivity and low stiffness conditions.

[0026] This implementation method, by combining upper and lower end caps with flexible ropes, establishes a prestressing loading mechanism that can be achieved without a complex rigid structure. This significantly reduces the overall system stiffness and improves the system's response sensitivity and dynamic matching performance. Simultaneously, by using an adjustable push-tightening mechanism to apply tension to the free end, continuously adjustable prestress control can be achieved, improving adjustment accuracy and system stability. Furthermore, the flexible force transmission path reduces the risk of stress concentration and extends the transducer's service life.

[0027] In one possible implementation, multiple flexible rope groups are arranged circumferentially and uniformly on the outside of the rare earth drive rod.

[0028] The structure arranges multiple flexible rope groups at equal intervals along the circumference of the rare earth drive rod, so that the rope groups are evenly distributed around the rare earth drive rod. When prestress is applied, the force in each direction remains symmetrical, avoiding unbalanced loads or eccentric forces during the operation of the transducer, thereby improving the stability and energy conversion efficiency of the system.

[0029] This arrangement ensures that the device is balanced in all directions under stress, effectively avoiding the degradation of transducer performance or component fatigue caused by eccentric loads. At the same time, the evenly distributed rope assemblies help simplify the assembly process, improve structural compactness, and facilitate mass production and on-site maintenance.

[0030] In one possible implementation, both the first rope and the second rope are steel wire ropes.

[0031] By selecting high-strength and highly flexible steel wire ropes as flexible force transmission elements, they can not only effectively withstand large tensile forces without easily breaking, but also exhibit good compliance and fatigue resistance during adjustment. The stable structural properties of the steel wire ropes also allow them to maintain predetermined tension characteristics during multiple loading / unloading cycles.

[0032] Using steel wire rope as the prestressing loading component significantly improves the reliability and lifespan of the device, making it suitable for long-term operation under complex or harsh conditions. Furthermore, its simple structure and moderate cost facilitate large-scale application.

[0033] In one possible implementation, the adjustable propulsion mechanism includes an adjusting screw and an adjusting nut. The adjusting screw has a through hole along its length, and the adjusting nut is threaded onto the threaded portion of the adjusting screw. The free ends of a first rope and a second rope pass through the through hole of the adjusting screw, and the adjusting screw is located between a first latch and a second latch.

[0034] This structure utilizes the rotational displacement characteristics of the adjusting screw's thread. By rotating the adjusting nut, the screw's axial movement is achieved, which in turn drives the free end of the rope, which is inserted into the through hole, to move forward or backward, thereby changing the rope tension and achieving precise adjustment of prestress.

[0035] This adjustment mechanism features a simple structure, high control precision, and excellent operability and repeatability. The through-hole structure ensures the stability and smoothness of rope threading, preventing rope damage or jamming and improving the overall reliability of the machine.

[0036] In one possible implementation, the first latch and the second latch include a locking head and a locking screw, the locking screw being detachably connected to the locking head.

[0037] This structure uses a screw connection, allowing for easy assembly and disassembly of the locking mechanism during use. Tightening or loosening the locking screws enables effective clamping or release of the rope, ensuring reliable rope fixation and flexible adjustment during assembly.

[0038] The locking assembly features a simple structure, making installation and maintenance convenient and improving assembly and replacement efficiency. Its detachable design provides good maintainability and versatility, meeting adjustment needs in various scenarios.

[0039] In one possible implementation, the locking head is made of stainless steel.

[0040] The locking head is made of stainless steel, which ensures good corrosion resistance and mechanical strength under high stress and variable environments, thus extending the service life of the component.

[0041] Stainless steel material significantly enhances the wear resistance and fatigue resistance of locking components during long-term use, effectively preventing structural loosening or failure due to corrosion or fatigue damage, and improving the overall system safety and reliability.

[0042] In one possible implementation, the number of flexible rope groups is eight, and each flexible rope group includes a first rope and a second rope.

[0043] By setting up eight sets of flexible ropes, each set forming an upper and lower paired structure to achieve a symmetrical distribution, the tensile stress applied to the rare earth drive rod can be distributed more evenly, thereby improving the mechanical stability of the overall system.

[0044] Based on the above scheme, multiple evenly distributed steel wire ropes are added to the outside of the rare earth rod of the transducer. The prestress is controlled by the tensile force of these multiple steel wire ropes. Since the thickness and number of steel wire ropes are highly adjustable, the prestress of the rare earth drive rod can be finely adjusted. The relationship between the tension P of the steel wire rope and its diameter r and number n is as follows:

[0045] In the formula This represents the tension of the wire rope. l Where E is the original length of the wire rope and E is the Young's modulus of the wire rope, the adjustable prestressing loading accuracy is improved compared to the traditional screw prestressing method.

[0046] For low-frequency transducers, if the screw radius is typically 5mm and the wire rope is 1mm, the prestressing loading accuracy is increased by 25 times. Therefore, a smaller prestress can be applied to meet the requirements, thus reducing costs. Furthermore, the increased equivalent stiffness is also reduced by 25 times, because the equivalent stiffness of a cylinder is... Proportional to the cross section S, as shown in equation (1):

[0047] The prestressing loading method is as follows: a pressure machine is used to first preload a force F0, then the n steel wire ropes are allowed to tighten naturally, and finally F0 is unloaded. At this point, we have:

[0048] The final prestress F applied to the transducer drive rod is:

[0049] Where E is the Young's modulus of the wire rope and S is the cross-sectional area.

[0050] Standard steel wire rope components are typically made of stainless steel. When it is necessary to close and tighten the steel wire rope, traditional welding methods suffer from insufficient strength and high welding difficulty. Therefore, this invention proposes an improved structure that uses a double steel wire rope lock with a positioning tightening nut. The axial thrust generated by the rotation of the nut achieves reliable tightening of the steel wire rope.

[0051] The specific operating steps are as follows: First, thread the wire rope through the first wire lock as usual; then, insert the hollow screw with a nut at one end onto the wire rope, bringing the nut end close to the installed lock; next, thread the wire rope through the second wire lock at the tail of the hollow screw and tighten this lock to limit axial displacement of the screw. Then, slowly rotate the nut on the hollow screw, causing it to push the first wire lock at the front end, thereby gradually tightening the wire rope. After the wire rope is tightened to the desired tension, lock the first wire lock to maintain tension. Subsequently, remove the second wire lock for limiting and the nut on the hollow screw in sequence, and add a second formal lock at the tightened section to further improve the reliability of the overall locking structure.

[0052] Example 2: A method for using a low-stiffness prestressing device for a rare-earth bending transducer, employing the device described in any one of claims 1-6, the method comprising: Step S1: Arrange the first rope and the second rope in a loop around the outside of the rare earth drive rod, connect the upper end cap of the rare earth drive rod to one end of the first rope, and connect the lower end cap of the rare earth drive rod to one end of the second rope. Step S2: Fit the adjusting nut onto the adjusting screw, and pass the other ends of the first rope and the second rope through the second buckle, the adjusting screw, and the first buckle in sequence. The adjusting screw is located between the first buckle and the second buckle, the first buckle is located on the side closer to the free ends of the first rope and the second rope, and the second buckle is located on the side away from the free ends of the first rope and the second rope. Step S3: Lock the first latch; Step S4: Rotate the adjusting nut to push the adjusting screw forward and move the first locking buckle, thereby tightening the first and second ropes; Step S5: Lock the second lock, release the first lock, and remove the first lock, adjusting screw, and adjusting nut from the first and second ropes; Step S6: Thread the first lock onto the first rope and the second rope, so that the first lock is against the back of the second lock, and lock the first lock.

[0053] Example 3: like Figure 1As shown, a low-stiffness prestressing device for a rare-earth bending transducer includes components such as a first locking buckle 1, a hollow screw 2, a forward nut 3, a second locking buckle 4, and steel wire ropes 5. The steel wire ropes 5 are evenly distributed in a circumferential manner on the outside of a rare-earth drive rod 6. The rare-earth drive rod 6 has a diameter of 20mm and a total of 8 sections of steel wire rope 5, each section containing two steel wire ropes 5, for a total of 16 ropes, used to construct a symmetrical and balanced prestressing loading system.

[0054] The implementation process first uses a universal press (Sansi Zongheng) to apply an initial constant load of 3000N to the rare earth drive rod 6. Under load, the wire rope 5 is sequentially passed through the upper and lower end caps of the rare earth drive rod 6, and at one end, the second locking buckle 4, the advancing nut 3, the hollow screw 2, and the first locking buckle 1 are sequentially inserted. After the components are inserted, the advancing nut 3 is first screwed into the thread of the hollow screw 2, and then the first locking buckle 1 is tightened to limit the initial tension position of the wire rope 5. Figure 2 As shown.

[0055] Next, by rotating the forward nut 3 in the opposite direction, an axial thrust is generated to push the hollow screw 2, thereby causing the first locking buckle 1 at the front end to move forward, thus gradually tightening the wire rope 5. When the wire rope 5 reaches the natural tightening state, the rotation of the forward nut 3 is stopped, and the first locking buckle 1 is finally locked to fix it at the target prestress position.

[0056] After tightening is complete, the tightening mechanism is removed. First, the first locking latch 1 used for limiting is removed, then the hollow screw 2 and the forward nut 3 are removed in sequence to release the temporary tightening structure, preparing for the final locking operation. Figure 3 As shown.

[0057] In the final fixing stage, the new first locking buckle 1 is re-threaded onto the tightened steel wire rope 5 and pushed to a position close to the second locking buckle 4, completing the locking operation again to ensure the stability and reliability of the prestressed fixing state, thereby realizing the prestressing loading process of the entire rare earth drive rod 6.

[0058] The specific component parameters are as follows: the first locking buckle 1 and the second locking buckle 4 are both 2.5mm steel wire rope 5 locking heads made of 304 stainless steel, equipped with two 3mm vertical fastening screws, internal hexagonal structure, and brand name Dixin; the hollow screw 2 is made of 304 stainless steel, specification M10×20, center hole diameter 5.2mm, selected from Tianzhuo Hardware; the forward nut 3 is a matching 304 stainless steel M10 nut, from Tiancheng Hardware; the steel wire rope 5 has a diameter of 2.5mm and a length of 18mm, and brand name Dixin.

[0059] like Figure 4As shown, the prestress on the rare earth rod can be increased controllably with the number of steel wire ropes. In a specific example, the number of steel wire ropes is 16, the initial loading force of the press is 3000N, and the prestress on the rare earth rod is 9.5MPa. like Figure 5 As shown in the measured curves of the rare earth bending transducer, under the low stiffness prestressed loading method of the steel wire rope 5 of the present invention, compared with the screw prestressed loading method, its current response in the low frequency range of 400-650Hz is higher, and the resonant frequency is reduced from about 650Hz to 550Hz. This proves that the prestressed loading method of the present invention has a lower impact on the equivalent stiffness of the system and is more suitable for prestressed loading of low frequency transmitting transducers.

[0060] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0061] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A low-stiffness prestressing application device for a rare-earth bending-tension transducer, characterized in that, It includes multiple flexible rope groups, a first lock (1), a second lock (4), an adjustable pushing mechanism, and a rare earth driving rod (6). Each flexible rope group includes at least one first rope and a second rope. At least one first rope in each flexible rope group has one end connected to the upper end cap of the rare earth driving rod (6), and the other end of the first rope is a free end extending toward the lower end cap. At least one second rope in each flexible rope group has one end connected to the lower end cap of the rare earth driving rod (6), and the other end of the second rope is a free end extending toward the upper end cap. The free ends of the first rope and the second rope pass through the second lock (4), the adjustable pushing mechanism, and the first lock (1) in sequence.

2. The apparatus according to claim 1, characterized in that, The multiple flexible rope groups are evenly arranged circumferentially on the outside of the rare earth drive rod (6).

3. The apparatus according to claim 1, characterized in that, Both the first rope and the second rope are steel wire ropes (5).

4. The apparatus according to claim 1, characterized in that, The adjustable propulsion mechanism includes an adjusting screw, a hollow screw (2), and a forward nut (3). The adjusting screw has a through hole along its length. The adjusting nut (3) is threaded onto the threaded part of the hollow screw (2). The free ends of the first rope and the second rope are inserted into the through hole of the hollow screw (2). The hollow screw (2) is located between the first latch (1) and the second latch (4).

5. The apparatus according to claim 1, characterized in that, The first latch (1) and the second latch (4) include a locking head and a locking screw, wherein the locking screw is detachably connected to the locking head.

6. The apparatus according to claim 5, characterized in that, The locking head is made of stainless steel.

7. The apparatus according to claim 1, characterized in that, The number of flexible rope groups is eight, and each flexible rope group includes a first rope and a second rope.

8. A method for using a low-stiffness prestressing application device for a rare-earth bending-tension transducer, characterized in that, Using any one of the devices described in claims 1-6, the method of use includes: Step S1: arranging the first rope and the second rope circumferentially outside the rare earth drive rod (6), connecting the upper end cap of the rare earth drive rod (6) to one end of the first rope, and connecting the lower end cap of the rare earth drive rod (6) to one end of the second rope; Step S2: fitting the adjusting nut (3) onto the hollow screw (2), and passing the other ends of the first rope and the second rope sequentially through the second buckle (4), the hollow screw (2), and the first buckle (1), wherein the hollow screw (2) is located between the first buckle (1) and the second buckle (4), and the first buckle (1) is located close to the first rope and the second rope. On one side of the free end of the rope, the second lock (4) is located away from the free ends of the first rope and the second rope; Step S3: Lock the first lock (1); Step S4: Rotate the adjusting nut (3) to push the hollow screw (2) forward to move the first lock (1) and tighten the first rope and the second rope; Step S5: Lock the second lock (4), loosen the first lock (1), and remove the first lock (1), hollow screw (2), and adjusting nut (3) from the first rope and the second rope; Step S6: Put the first lock (1) on the first rope and the second rope, so that the first lock (1) abuts against the back of the second lock (4) and lock the first lock (1).

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