Ultrasonic fatigue test torsional amplitude measuring device

Abstract

The application provides an ultrasonic fatigue test torsional amplitude measuring device, and belongs to the technical field of material torsional fatigue strength testing. The surface of the base is provided with a rack and an amplitude measuring assembly. The vibration assembly is movably arranged on the rack along the gravity direction. The amplitude measuring assembly is movably arranged relative to the base. The amplitude measuring assembly is provided with a centering sleeve. The monitoring surface of the connected torsional sample and the measuring instrument are at the same angle each time through the centering sleeve. Therefore, the measuring point can be accurately grasped when the amplitude measuring assembly measures. In addition, the torsional sample and the centering sleeve are also surface-to-surface adhered, the connection position of the torsional sample and the centering sleeve is determined, and the most accurate monitoring result is obtained.

Description

Technical Field

[0001] This application relates to the field of material torsional fatigue strength testing technology, and in particular to an ultrasonic fatigue test torsional amplitude measuring device. Background Technology

[0002] Ultrasonic fatigue testing technology utilizes the resonance principle, where a transducer converts a 20kHz electrical signal generated by an ultrasonic generator into mechanical vibrations of the same frequency; this method enables the testing of ultra-high cycle fatigue properties of materials. Due to its high frequency and stable loading characteristics, ultrasonic fatigue technology has become the primary experimental method for studying the ultra-high cycle fatigue properties of materials.

[0003] Torsional fatigue testing is one of its important testing methods. The general testing method is to cut a groove at the end of the specimen, measure the tangential amplitude, and convert it into torsional amplitude. The traditional connection method is to apply vibration to the specimen by connecting the specimen to the amplitude transformer of the vibration component through a threaded connection. However, during the threaded rotation connection, the position of the groove in the monitoring area at the end of the specimen changes every time the specimen is replaced. Therefore, the position of the measuring instrument used for monitoring must be adjusted accordingly to ensure that the monitoring area of ​​the measuring instrument is at the groove position of the specimen. Therefore, this method is cumbersome to adjust and cannot guarantee the consistency of the measurement.

[0004] Therefore, a measuring device is needed that can ensure that the sample can be monitored without adjusting the measuring instrument each time the sample is changed. Utility Model Content

[0005] One of the technical problems this application aims to solve is that when existing testing devices monitor samples, the instrument monitoring area must be adjusted every time the sample is changed, which is cumbersome and cannot guarantee the consistency of the measurement.

[0006] To address the aforementioned technical problems, this application provides an ultrasonic fatigue test torsional amplitude measuring device, comprising a torsion specimen, a connector at the first end of the torsion specimen, a first groove at the second end of the torsion specimen, and a monitoring surface along the radial direction of the center of the torsion specimen on one side of the first groove, and further comprising: The base has a frame and an amplitude measuring component on its surface. A vibration component is movably mounted on the frame along the direction of gravity. The vibration component is connected to the first end of the torsion specimen to drive the torsion specimen to vibrate tangentially. The amplitude measuring component is used to monitor the torsion amplitude of the torsion specimen. The amplitude measuring component is movably mounted relative to the base. The amplitude measuring component has an alignment sleeve with a first slot on its surface. The second end of the torsion specimen fits into the first slot to determine the relative position of the torsion specimen and the amplitude measuring component. The torsion specimen and the alignment sleeve are located on the same axis.

[0007] In some embodiments, the aforementioned ultrasonic fatigue test torsional amplitude measuring device includes an amplitude measuring component comprising a column, a connecting plate, and a measuring instrument; One end of the column is connected to the base, and the other end of the column is fixedly connected to the connecting plate. The connecting plate is equipped with a slide table, which is movably set relative to the connecting plate in the first direction. The measuring instrument is located on the slide table and emits measuring light to monitor the torsional amplitude of the monitoring surface. Among them, the positive sleeve is located on the connecting plate, and the first direction is the width direction of the connecting plate.

[0008] In some embodiments, the aforementioned ultrasonic fatigue test torsional amplitude measuring device further includes a protective plate on the connecting plate, which is located between the alignment sleeve and the slide table, and has elongated holes to allow measurement light to pass through.

[0009] In some embodiments, the aforementioned ultrasonic fatigue test torsional amplitude measuring device includes a guide post on the surface of the connecting plate, the guide post extending toward the side away from the column, and the alignment sleeve being movably arranged relative to the guide post; wherein there are two guide posts, and the two guide posts are spaced apart along a first direction.

[0010] In some embodiments, the aforementioned ultrasonic fatigue test torsional amplitude measuring device includes a groove at the bottom of the connecting plate, the shape of which is the same as that of the column, and the column is connected to the connecting plate from the groove.

[0011] In some embodiments, the aforementioned ultrasonic fatigue test torsional amplitude measuring device includes a vibration component comprising a movable crossbeam, an upper tensioning sleeve, a drive component, and a lower connecting component. The movable crossbeam is movably connected to the frame, the upper tension sleeve is fixedly connected to the movable crossbeam, a connecting frame is provided between the upper tension sleeve and the lower connecting assembly, the driving component is located on the connecting frame, the lower connecting assembly is connected to the first end of the torsion specimen, and the lower connecting assembly is connected to the driving component to drive the torsion specimen to vibrate. One end of the upper tension sleeve is equipped with a control screw, which can be rotated to increase or decrease the pressure of the oil in the upper tension sleeve to lock or release the connecting frame.

[0012] In some embodiments, the aforementioned ultrasonic fatigue test torsional amplitude measuring device includes a lower connecting assembly comprising an amplitude transformer, a pressure cap, and an adjusting ring. The adjusting ring is connected to the bottom of the connecting frame, the bottom of the amplitude rod is connected to the first end of the torsion specimen, and the pressure cap is located outside the amplitude rod to connect the amplitude rod to the adjusting ring; The other end of the amplitude rod is connected to the drive component.

[0013] In some embodiments, the aforementioned ultrasonic fatigue test torsional amplitude measuring device includes a set screw on the side wall of the adjusting ring to adjust the position of the amplitude transformer rod in the radial direction.

[0014] In some embodiments, the aforementioned ultrasonic fatigue test torsional amplitude measuring device is provided, wherein the shape of the second end of the torsional specimen is adapted to the shape of the first slot.

[0015] Through the above technical solution, the ultrasonic fatigue test torsional amplitude measuring device provided by this application can ensure that the torsional specimens connected each time are at the same angle by setting the alignment sleeve. Therefore, the measurement point can be accurately grasped when the amplitude measuring component is measuring. In addition, the torsional specimen and the alignment sleeve are also in surface-to-surface contact, which determines the connection position between the torsional specimen and the alignment sleeve. Therefore, even if different torsional specimens are replaced for monitoring, since the relative position of the alignment sleeve and the amplitude measuring component is fixed, the position of the torsional specimen and the alignment sleeve is also fixed. When the amplitude measuring component is monitoring, it can be directly facing the monitoring surface on the torsional specimen to obtain the most accurate data and thus obtain the most accurate monitoring results. Compared with the traditional method that requires adjustment of the amplitude measuring component, it is faster and more convenient. In addition, the connection method between the positive sleeve and the torsion specimen is faster and improves the monitoring efficiency more quickly. At the same time, the connection angle is fixed, and the threaded connection method between the torsion specimen and the vibration component will not affect the monitoring of the angle of the amplitude measurement component. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of an ultrasonic fatigue test torsional amplitude measuring device disclosed in an embodiment of this application; Figure 2 This is a schematic diagram of the amplitude measurement component structure of an ultrasonic fatigue test torsional amplitude measuring device disclosed in an embodiment of this application; Figure 3 This is a cross-sectional structural schematic diagram of the vibration component of an ultrasonic fatigue testing torsional amplitude measuring device disclosed in an embodiment of this application; Figure 4 This is a schematic diagram of the torsion specimen structure of an ultrasonic fatigue testing torsion amplitude measuring device disclosed in an embodiment of this application; Figure 5This is a schematic diagram of the bottom structure of a torsion specimen of an ultrasonic fatigue testing torsion amplitude measuring device disclosed in an embodiment of this application; Figure 6 This is a schematic diagram of the alignment sleeve of an ultrasonic fatigue test torsional amplitude measuring device disclosed in an embodiment of this application; Figure 7 This is a schematic diagram of the connection between the alignment sleeve and the torsion specimen of an ultrasonic fatigue test torsion amplitude measuring device disclosed in an embodiment of this application; Figure 8 This is a schematic diagram of the structure of the connecting plate of an ultrasonic fatigue test torsional amplitude measuring device disclosed in an embodiment of this application; Figure 9 This is a schematic diagram of the connecting plate of an ultrasonic fatigue test torsional amplitude measuring device disclosed in an embodiment of this application.

[0018] Explanation of reference numerals in the attached figures: 1. Torsion specimen; 2. Connector; 3. Monitoring surface; 4. Base; 5. Frame; 6. Amplitude measuring assembly; 601. Column; 602. Connecting plate; 603. Measuring instrument; 7. Vibration assembly; 701. Moving crossbeam; 702. Upper tension sleeve; 703. Drive component; 704. Lower connecting assembly; 7041. Amplitude rod; 7042. Pressure cap; 7043. Adjusting ring; 8. Alignment sleeve; 9. First slot; 10. Slide table; 11. Guard plate; 12. Long slot; 13. Guide column; 14. Groove; 15. Connecting frame; 16. Control screw; 17. Set screw; 18. First slot; A. First direction. Detailed Implementation

[0019] To better explain and facilitate understanding of the present invention, a detailed description of the invention is provided below with reference to the accompanying drawings and specific embodiments. To further understand the above technical solutions, exemplary embodiments of the invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a clearer and more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0020] Example 1 Reference Appendix Figure 1 , Figure 4 and Figure 5This embodiment discloses an ultrasonic fatigue test torsional amplitude measuring device, which includes: a torsion specimen 1, wherein the torsion specimen 1 is a standard sample for torsion testing. The structure of the torsion specimen 1 is that one end is provided with a connector 2 and the other end is provided with a first groove 18. A monitoring surface 3 extends radially outward from one side of the first groove 18. This monitoring surface 3 is a flat end face. It can be understood that the change data of the torsional amplitude of the torsion specimen 1 before and after vibration can be collected from this point by an external amplitude measuring component 6. The raw data can be obtained from this data to calculate other mechanical performance indicators of the torsion specimen 1.

[0021] Specifically, to ensure more accurate test data, this application provides an alignment sleeve 8 on the amplitude measuring component 6 that matches the shape of the torsion sample 1. The alignment sleeve 8 has a first slot 9, the shape of which matches the shape of the torsion sample 1 and its connection end. Therefore, when the torsion sample 1 is connected to the alignment sleeve 8, the position of the monitoring surface 3 is fixed. When the amplitude measuring component 6 monitors the monitoring surface 3, it can accurately collect data from the monitoring surface 3, resulting in the most accurate data. Furthermore, although the torsion sample 1 can be connected to the vibration component 7 via, but not limited to, a threaded connection, and the position of the first slot 18 will change after a stable connection, the amplitude measuring component 6 can be rotated to a position directly opposite the first slot 18, achieving a precise connection.

[0022] The torsional amplitude measuring device provided in this embodiment is mainly used for monitoring this type of torsional sample 1. The torsional sample 1 is structurally compatible with the alignment sleeve 8. It can be understood that when testing the same batch of torsional samples 1, the alignment sleeve 8 is always connected to the amplitude measuring component 6. Only the torsional sample 1 on the vibration component 7 needs to be removed. After replacing it with a new torsional sample 1, the vibration measuring component 6 is rotated for testing. When monitoring different batches of torsional samples 1, the corresponding alignment sleeve 8 needs to be replaced. When replacing the alignment sleeve 8, only the size of the first slot 9 in the alignment sleeve 8 changes with the torsional sample 1. The outer diameter of the alignment sleeve 8 does not change. Therefore, the alignment sleeve 8 and the amplitude measuring component 6 are always precisely connected. Thus, accurate data can be obtained when monitoring. At the same time, during vibration, it is necessary to ensure that the vibration component 7, the torsional sample 1, and the amplitude measuring component 6 are located on the same axis to achieve vibration uniformity, thereby obtaining the most accurate data and reducing damage to the torsional sample.

[0023] Next, refer to the appendix Figure 1 , Figure 2 , Figure 6 , Figure 7 and Figure 8The amplitude measurement component 6 includes a column 601, a connecting plate 602, and a measuring instrument 603. The column 601 is a rigid column supporting the connecting plate 602 and the measuring instrument 603. A buffer pad is provided at the bottom of the column 601 to reduce rigid impact between the column 601 and the base 4. The measuring instrument 603 is a general term for a device used to monitor the torsional amplitude of the monitoring surface 3. The measuring instrument 603 emits monitoring light perpendicular to the surface of the monitoring surface 3, accurately acquiring changes in the monitoring surface 3. The measuring instrument 603 is mounted on a slide table 10, which is driven by a gear and rack. Adjustment is achieved by manually rotating a handle to move the measuring instrument 603 back and forth along the first direction A. It is understood that although the angle is limited when the torsional sample 1 is connected to the first slot 9, the monitoring surface 3 has a certain radial distance, making it impossible to guarantee that the monitoring point is close to the edge. Therefore, fine-tuning of the measuring instrument 603 is necessary to ensure that the monitoring light is accurately emitted to the edge of the monitoring surface 3 for monitoring. The positive sleeve 8 is connected to the connecting plate 602... 02 During connection, precise connection can be achieved through the guide posts 13 on the connecting plate 602. There are two guide posts 13, symmetrically arranged along the first direction A. The outer circumference of the alignment sleeve 8 is circular, and it has through holes corresponding to the positions of the guide posts 13, i.e., radially arranged. During connection, the guide posts 13 pass through the through holes, achieving precise connection of the alignment sleeve 8. Furthermore, when testing different batches of torsion samples 1 and changing the alignment sleeve 8, quick connection can be achieved through the guide posts 13, without needing to consider angles, directions, or whether it maintains the same axis as the vibration component 7, thus improving testing efficiency. The bottom of the connecting plate 602 also has a groove 14, and the shape of the column 601 matches the shape of the groove 14. The connection of the column 601 from the groove 14 improves the compatibility between the column 601 and the connecting plate 602 and determines the connection direction. The alignment sleeve 8 and the measuring instrument 603 on the connecting plate 602 are located at opposite ends of the connecting plate 602, and the column 601 connects at the end where the alignment sleeve 8 is located. The groove 14 is designed to quickly determine the connection position and also to wrap the column 601 to prevent the connecting plate 602 from shifting laterally.

[0024] Next, during the test, the torsion specimen 1 is first connected to the vibration component 7, and the vibration component 7 is adjusted so that the torsion specimen 1 on the vibration component 7 is close to the alignment sleeve 8. Under the action of the guide column 13, the alignment sleeve 8 moves upward and closes to the torsion specimen 1, ensuring that the first slot 18 can be smoothly inserted into the first slot hole 9 to achieve connection, thereby enabling the subsequent test to proceed smoothly. If the connection cannot be made smoothly, the column 601 needs to be rotated to change the position of the first slot hole 9 until the first slot 18 can be smoothly inserted into the first slot hole 9. During this period, the alignment sleeve 8 is always connected to the guide column 13. After the position of the alignment sleeve 8 is determined, the column 601 is fixed. The column 601 is provided with a lower expansion sleeve on the outside to fix the column 601 to the base 4. Then the alignment sleeve 8 is separated from the torsion specimen 1, and the measuring instrument 603 monitors the monitoring surface 3 on the torsion specimen 1.

[0025] Additionally, see attached document. Figure 2 The connecting plate 602 is also equipped with a protective plate 11, which is used to protect the measuring instrument 603. It is understood that the torsion sample 1 may break during the test, and the broken half of the sample will cause damage to the measuring instrument 603. The protective plate 11 is inverted "L" shape and has an elongated hole 12. The elongated hole 12 can be used to allow the monitoring light to pass through. When the protective plate 11 is connected to the connecting plate 602, it is connected to the threaded hole on the connecting plate 602 by a nut. There are multiple sets of threaded holes, so the threaded holes at different positions can be selected for connection according to the size of the measuring instrument 603, and the distance between the protective plate 11 and the measuring instrument 603 can be changed to adapt to measuring instruments 603 of different sizes.

[0026] Next, refer to the appendix Figure 1 , Figure 3 and Figure 9The vibration assembly 7 includes a movable crossbeam 701, an upper tension sleeve 702, a drive component 703, and a lower connecting assembly 704. The movable crossbeam 701 is movably connected to the frame 5. The movable crossbeam 701 contains a moving component, which can be controlled by an external controller to move or stop the movable crossbeam 701 on the frame 5. The upper tension sleeve 702 is connected to a protrusion at the bottom center of the movable crossbeam 701. The upper tension sleeve 702 is a connecting sleeve containing hydraulic oil. A control screw 16 is provided on the upper tension sleeve 702. By screwing in the control screw 16, the hydraulic oil inside the upper tension sleeve 702 is compressed, increasing the internal pressure. The inner wall of the upper tension sleeve 702 locks the end connected to the movable crossbeam 701, ensuring a stable connection. Similarly, unscrewing the control screw 16 releases the pressure. The hydraulic oil inside the upper tension sleeve 702 reduces the internal pressure, causing the inner wall of the upper tension sleeve 702 to release the end connected to the moving crossbeam 701, thus separating the upper tension sleeve 702 from the moving crossbeam 701. Since the connection between the moving crossbeam 701 and the upper tension sleeve 702 is a plug-in connection, relative rotation is not required. Therefore, when the torsion specimen 1 is connected to the lower connecting assembly 704, the angle of the already fixed torsion specimen 1 will not be changed again, thus achieving a stable connection between the torsion specimen 1 and the alignment sleeve 8. A separate connecting frame 15 is also provided between the upper tension sleeve 702 and the lower connecting assembly 704. The connecting frame 15 is used to place the driving component 703, providing power for the rotation of the torsion specimen 1. The lower connecting assembly 704 is the general term for the device used to connect the torsion specimen 1.

[0027] Additionally, see attached document. Figure 3 The lower connecting assembly 704 includes an amplitude transformer 7041, a pressure cap 7042, and an adjusting ring 7043. The amplitude transformer 7041 is adapted to the connector 2 of the torsion specimen 1. It can be understood that when the torsion specimen 1 is connected, the torsion specimen 1 is connected to the amplitude transformer 7041, and then the pressure cap 7042 is fastened to the outside of the amplitude transformer 7041. The fixing screw on the pressure cap 7042 is used to tighten it with the adjusting ring 7043 to achieve fixation. The adjusting ring 7043 is provided with an adjusting screw to stably connect the adjusting ring 7043 to the bottom of the connecting frame 15. The uniformity of the axis can be ensured by fine adjustment of the set screw 17 on the adjusting ring 7043.

[0028] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0030] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0031] In the description of this specification, the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples", etc., refer to the specific features, structures, materials or characteristics described in connection with that embodiment or example that are included in at least one embodiment or example of the present invention.

[0032] In this specification, the illustrative expressions of the terms used do not necessarily refer to the same embodiments or examples. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples, without contradiction.

[0033] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An ultrasonic fatigue test torsional amplitude measuring device, comprising a torsion specimen (1), wherein a connector (2) is provided at a first end of the torsion specimen (1), and a first groove (18) is provided at a second end of the torsion specimen (1), wherein a monitoring surface (3) is provided on one side of the first groove (18) along the radial direction of the center of the torsion specimen (1), characterized in that, Also includes: A base (4) is provided with a frame (5) and an amplitude measuring component (6) on its surface. A vibration component (7) is movably arranged on the frame (5) along the direction of gravity. The vibration component (7) is connected to the first end of the torsion specimen (1) to drive the torsion specimen (1) to vibrate tangentially. The amplitude measuring component (6) is used to monitor the torsional amplitude of the torsion specimen (1). The amplitude measuring component (6) is movably arranged relative to the base (4). An alignment sleeve (8) is provided on the amplitude measuring component (6). A first slot (9) is provided on the surface of the alignment sleeve (8). The second end of the torsion specimen (1) is attached to the first slot (9) to determine the relative position of the torsion specimen (1) and the amplitude measuring component (6). The torsion specimen (1) and the alignment sleeve (8) are located on the same axis.

2. The ultrasonic fatigue test torsional amplitude measuring device according to claim 1, characterized in that, The amplitude measurement component (6) includes a column (601), a connecting plate (602), and a measuring instrument (603). One end of the column (601) is connected to the base (4), and the other end of the column (601) is fixedly connected to the connecting plate (602). The connecting plate (602) is provided with a slide (10). The slide (10) is movably arranged relative to the connecting plate (602) along a first direction. The measuring instrument (603) is located on the slide (10) to emit measuring light to monitor the torque amplitude of the monitoring surface (3). The alignment sleeve (8) is located on the connecting plate (602), and the first direction is the width direction of the connecting plate (602).

3. The ultrasonic fatigue test torsional amplitude measuring device according to claim 2, characterized in that, The connecting plate (602) is also provided with a guard plate (11), which is located between the alignment sleeve (8) and the slide (10). The guard plate (11) is provided with an elongated hole (12) to allow the measuring light to pass through.

4. The ultrasonic fatigue test torsional amplitude measuring device according to claim 2, characterized in that, The surface of the connecting plate (602) is provided with a guide post (13), the guide post (13) extends toward the side away from the column (601), and the alignment sleeve (8) is movably arranged relative to the guide post (13); There are two guide posts (13), and the two guide posts (13) are spaced apart along the first direction.

5. The ultrasonic fatigue test torsional amplitude measuring device according to claim 2, characterized in that, The bottom of the connecting plate (602) is provided with a groove (14), the shape of which is the same as that of the column (601), and the column (601) is connected to the connecting plate (602) from the groove (14).

6. The ultrasonic fatigue test torsional amplitude measuring device according to claim 1, characterized in that, The vibration assembly (7) includes a movable crossbeam (701), an upper tension sleeve (702), a drive component (703), and a lower connecting assembly (704). The movable crossbeam (701) is movably connected to the frame (5), the upper tension sleeve (702) is fixedly connected to the movable crossbeam (701), a connecting frame (15) is provided between the upper tension sleeve (702) and the lower connecting assembly (704), the driving member (703) is located on the connecting frame (15), the lower connecting assembly (704) is connected to the first end of the torsion specimen (1), and the lower connecting assembly (704) is connected to the driving member (703) to drive the torsion specimen (1) to vibrate; One end of the upper expansion sleeve (702) is provided with a control screw (16) so as to lock or release the connecting frame (15) by increasing or decreasing the pressure of the oil in the upper expansion sleeve (702) through rotation.

7. The ultrasonic fatigue test torsional amplitude measuring device according to claim 6, characterized in that, The lower connecting assembly (704) includes an amplitude rod (7041), a pressure cap (7042), and an adjusting ring (7043). The adjusting ring (7043) is connected to the bottom of the connecting frame (15), the bottom of the amplitude rod (7041) is connected to the first end of the torsion specimen (1), and the pressure cap (7042) is located outside the amplitude rod (7041) to connect the amplitude rod (7041) to the adjusting ring (7043). The other end of the amplitude rod (7041) is connected to the drive unit (703).

8. The ultrasonic fatigue test torsional amplitude measuring device according to claim 7, characterized in that, The sidewall of the adjusting ring (7043) is provided with a set screw (17) to adjust the adjusting ring (7043) radially to change the position of the amplitude rod (7041).

9. The ultrasonic fatigue test torsional amplitude measuring device according to claim 1, characterized in that, The shape of the second end of the torsion specimen (1) is adapted to the shape of the first slot (9).

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