CN101819114A - Ultrasonic bending fatigue experimental device - Google Patents

Abstract

An ultrasonic bending fatigue test device, the transducer is located in the force transmitter and connected with the connector. The power transmission device is located in the middle of the present invention; the backing plate of the power transmission device is fixedly connected with the upper connecting plate and the lower connecting plate by a dowel rod. One end of the connector passes through the lower connecting plate at the lower end of the force transmitter and is connected with the displacement amplifier; the other end passes through the upper connecting plate and is connected with the transducer. The supporting device is located under the displacement amplifier; the static load reinforcing device passes through the center hole of the backing plate and is fixedly connected with the backing plate. The transducer, connector, displacement amplifier and indenter of the present invention constitute a longitudinal resonance system, and the longitudinal vibration load is transmitted to the bending fatigue sample through the indenter, so that the bending fatigue sample generates bending vibration. The positioning screw can automatically adjust the position of the support point of the bending fatigue specimen, so as to realize the ultrasonic bending fatigue experiment, and can realize the ultrasonic bending fatigue experiment of samples with different loading loads and different geometric sizes, and is suitable for using axial loading ultrasonic fatigue testing machine Perform bending fatigue tests.

Description

Ultrasonic bending fatigue test device

technical field

The invention relates to the fields of structural material fatigue and durability testing, in particular to an ultrasonic bending fatigue test device.

Background technique

Fatigue failure is the main failure mode of structural parts under alternating loads, such as crankshafts, gears, connecting rods, springs, bolts and other components, as well as pressure vessels, vehicles, aircraft, offshore platforms, welded steel bridges and other structures. fatigue damage. The failure accidents of engineering components caused by fatigue damage account for 80% of the total accidents. Because fatigue fracture occurs suddenly and leads to catastrophic accidents, the fatigue failure of materials has always been a subject of research and concern by scholars and engineering circles at home and abroad.

In aerospace, automobile, railway, nuclear industry, machinery and other industrial fields, some structural parts have to bear high-frequency and low-amplitude cyclic loads during the working process, and the number of cyclic loads is as high as 10 ⁹ -10 ¹¹ weeks. Although the stress amplitude of high-frequency cyclic load is small, its frequency is very high, up to thousands of hertz, especially when this high-frequency, low-amplitude load is superimposed with other loads, the composite damage caused will greatly accelerate the damage of structural components, seriously Threats to the safety and reliability of structural components. Therefore, foreign countries pay special attention to the research of low-amplitude and ultra-high-cycle fatigue life in the study of fatigue life of high-speed operating structural parts. In recent years, the research on the ultra-high cycle fatigue behavior of engineering materials with more than 10 ⁷ cycles has become a new subject of fatigue research, which has attracted great attention from the engineering community.

Ultrasonic fatigue (Ultrasonic Fatigue) experimental technology adopts the resonance principle to convert the high-frequency electrical signal generated by the ultrasonic generator into a vibration displacement output with the same frequency through the transducer. This vibration displacement is amplified by the displacement amplifier to load the high-frequency cyclic stress In order to realize the ultrasonic high-frequency cyclic loading of structural materials, and then realize the experimental research on the ultra-high cycle fatigue performance of structural materials. Ultrasonic fatigue test technology has become an effective and reliable experimental method to obtain the ultra-high cycle fatigue performance of engineering materials.

The existing ultrasonic fatigue test device is mainly composed of an ultrasonic generator, a transducer, a high-magnification displacement amplifier, and a tension-compression fatigue sample (as shown in Figure 1). The transducer converts the alternating-frequency electrical signal into a vibration signal of the same frequency, and the high-magnification displacement amplifier amplifies the vibration displacement output by the transducer, and transmits it to the tension-compression fatigue specimen to form axial cyclic stress loading on the specimen. Since the existing ultrasonic fatigue test device does not have an experimental device that can convert the longitudinal wave into a transverse wave, at the same time, because in the existing axially loaded ultrasonic fatigue test device, the dynamic load preload and static load of the tension and compression fatigue specimen The direction is the same, and there is no need to consider the influence of static load on dynamic load, so there is no static load adding device in the structure, so the axial loading ultrasonic fatigue test device in the prior art can only realize axial loading of fatigue samples.

Contents of the invention

In order to overcome the deficiency in the prior art that only the axial loading of fatigue samples can be achieved, the present invention proposes an ultrasonic bending fatigue test device.

The invention includes a low-magnification displacement amplifier, a connector, a supporting device, a force transmitter and a transducer; the lower end of the transducer is connected to the connector through a screw. and

The transducer is located in the force transmitter; the force transmitter is located in the middle of the ultrasonic bending fatigue test device; the force transmitter includes a lower connecting plate, an upper connecting plate, a dowel rod and a backing plate, and the backing plate is located on the top of the force transmitting device, The upper connecting plate and the lower connecting plate are located at the lower end of the power transmission device. The backing plate is fixedly connected with the upper connecting plate and the lower connecting plate by a dowel rod. One end of the connector passes through the lower connecting plate at the lower end of the force transmitter to connect with the low-magnification displacement amplifier; the other end passes through the upper connecting plate to connect with the transducer.

The supporting device is located under the low-magnification displacement amplifier; the static load reinforcing device passes through the center hole of the backing plate and is fixedly connected with the backing plate.

The supporting device is a symmetrical structure, including a pressing block, an adjusting slider, a longitudinal adjusting screw, a sliding block, a supporting cover, a positioning sleeve, a positioning screw, a handle, a base, a horizontal adjusting screw, a supporting bar pressing block, a supporting bar and a sliding block Fixed plate; two sliders are symmetrically installed in the center of the base table, and two adjustment sliders are respectively located in the guide chute on the surface of the slider; two support covers are respectively located at both ends of the base table; the positioning screw passes through the The positioning lead screw installation groove on the base table is positioned through the positioning sleeve; the support bar is installed in the support bar installation groove on the slider, and the two ends of the support bar are respectively fixed by the pressing block and the support bar pressing block.

The spacer block is set on the dowel bar between the lower connecting plate and the upper connecting plate. One end of the dowel rod is connected with the backing plate, and the other end passes through the upper connecting plate, the isolation block and the lower connecting plate successively, and is fixed with a nut.

The center of the bottom plate of the base has a through hole that matches the positioning shaft of the test bench; the center of the table top of the base has a guide chute for the slider, and the center of the guide chute has a positioning block that protrudes from the inner surface of the chute. The two sides of the guide chute and the positioning lead screw installation groove of the slider communicate with each other from the inside to the outside.

The connecting block of the slider is located in the guide chute of the base, and the connecting block has a positioning screw connecting hole; the surface of the mounting block of the sliding block has an installation adjusting slider parallel to the positioning screw connecting hole on the connecting block The guide chute, and the center of the guide chute and the center of the positioning screw connection hole are on the same vertical plane; on one side of the surface of the slider mounting block, there is a support bar installation groove perpendicular to the guide chute.

The outer surface of the middle part of the positioning screw has two sections of external threads with opposite rotation directions; the two sections of external threads are respectively connected with a slider and placed in the guide chute of the base together; there are positioning sleeves at both ends of the positioning screw Mounting holes; the two ends of the positioning screw are fitted with a positioning sleeve, and one end of the positioning sleeve is close to the side wall of the base; the limit screw passes through the positioning groove on the side of the positioning sleeve and is inserted into the positioning screw on the positioning screw. In the screw hole; the positioning sleeve is clearance matched with the positioning lead screw through the inner hole.

There is a semicircular through hole for the positioning screw at the center of the bottom edge on both sides of the support cover; there are connecting holes at both ends of the cover surface of the support cover; when the positioning screw is connected with the slider and placed on the guide of the base together After being in the chute, the support cover is fixed on the base, and the semicircle groove on the lower surface of the support cover and the semicircle positioning lead screw installation groove on the base upper surface constitute a lead screw support seat for supporting the positioning lead screw to rotate freely.

The two sides of the adjusting slider are respectively provided with opening grooves, which are symmetrical to the center of the adjusting slider and have the same opening direction; the center of the adjusting slider has a mounting hole for a longitudinal adjusting screw.

There is a mounting hole for the horizontal adjustment screw in the middle of the side of the pressure block; below the mounting hole for the horizontal adjustment screw and at the bottom of the side of the pressure block, there is a groove for matching the compression support bar; the adjustment screw on the upper surface of the pressure block On both sides of the mounting hole, there are connecting holes of the slide block whose center line is perpendicular to the center line of the horizontal adjustment screw mounting hole. The connecting holes on the support bar pressing block are located on both sides of the pressing groove of the support bar. The sliding block is slidingly matched with the guide chute on the table top of the base; the diameter of the positioning lead screw installation groove is the same as the outer diameter of the positioning lead screw.

The invention applies the principle of resonance to ensure that the bending fatigue sample and the ultrasonic fatigue test system have the same resonance frequency, and realizes composite loading of different static loads and dynamic loads. The supporting part of the bending fatigue test device is driven by a screw and guided by a guide chute, so as to realize accurate positioning and loading of the bending fatigue test specimen. Since the system maintains resonance during the ultrasonic bending fatigue test, it is necessary to accurately calculate the resonance size of each component at a vibration frequency of 20kHz and accurately position the bending fatigue specimen. In the bending fatigue test device, a longitudinal automatic centering device and a lateral positioning device to ensure lateral positioning should be installed. Both the longitudinal and lateral positioning devices are controlled by the lead screw device, so as to realize the fatigue experiment of bending fatigue specimens of any geometric size.

The transducer, connector, low-magnification displacement amplifier and indenter of the present invention constitute a longitudinal resonance system, and the longitudinal vibration load is transmitted to the bending fatigue sample through the indenter, so that the bending fatigue sample generates bending vibration. The geometric dimensions of the bending fatigue specimen and the position of the support point are strictly calculated to meet the bending resonance condition of the same frequency as the longitudinal vibration load, thus causing the bending fatigue specimen to generate bending resonance. In the ultrasonic bending fatigue test device, a connector is designed. The dowel bar, the upper and lower connecting plates, and the isolation block constitute a force transmitting device. The upper and lower connecting plates of the force transmitting device are connected with the zero-displacement surface of the connector. The static load passes through the The zero displacement surface of the connector is applied to the bending sample to avoid the influence of the static load on the vibration wave of the system and ensure the resonance condition of the ultrasonic bending fatigue system. The positioning lead screw in the supporting device of the ultrasonic bending fatigue test can automatically adjust the position of the supporting point of the bending fatigue sample, and ensure the automatic centering of the bending fatigue sample, so as to realize the ultrasonic bending fatigue test.

The connector of the present invention is designed according to the vibration wave theory. There is a zero-vibration displacement surface on the connector, and the static load force device is connected to the zero-vibration displacement surface of the connector. The load is transmitted to the bending fatigue specimen, and the transmission between the dynamic load and the static load does not affect each other. The design of the bending fatigue specimen is based on the transverse wave wave theory, and the loading point and support point are designed. The exact position of the loading point and the supporting point is achieved by adjusting the supporting device. In the present invention, the support bar is fixed on the slider, and the internal thread of the slider and the positioning screw form a spiral motion, and the positioning screw can be rotated to push the slider, and the slider transmits force through the screw to make it slide along the guide chute in the base , and then determine the longitudinal displacement. The automatic centering of the curved specimen is realized by the two-way screw sliding device. At the same time, the lateral positioning adopted by the present invention is positioned by a single-side double guide post plus a screw side pusher device. The internal thread of the pressing block and the adjusting screw form a helical transmission, and the rotating adjusting screw can push the bending fatigue sample to ensure that the bending fatigue sample horizontal orientation. The support bar is installed on the slider and can be removed for replacement after wear and tear.

The application of the ultrasonic bending fatigue test device can effectively realize the ultrasonic bending fatigue test of bending fatigue samples with different loads and different geometric sizes. It is suitable for bending fatigue experiments using an axially loaded ultrasonic fatigue testing machine.

Description of drawings

Accompanying drawing 1 is the structural representation of the ultrasonic fatigue experiment device in the prior art;

Accompanying drawing 2 is the structural representation of ultrasonic bending fatigue test device;

Accompanying drawing 3 is the structural axonometric view of ultrasonic bending fatigue test device;

Accompanying drawing 4 is the distribution of vibration displacement under two kinds of experimental devices, wherein a is the axial vibration displacement curve of the axially loaded ultrasonic fatigue test device, b is the axial vibration displacement of the ultrasonic bending fatigue test device and the bending fatigue specimen bending Vibration displacement curve;

Accompanying drawing 5 is the structural representation of connector;

Accompanying drawing 6 is the structural representation of isolation block;

Accompanying drawing 7 is the structural representation of connecting plate;

Accompanying drawing 8 is the structural representation of backing plate;

Accompanying drawing 9 is the structural representation of low power displacement amplifier;

Accompanying drawing 10 is the structural representation of pressure head;

Accompanying drawing 11 is the axonometric view of supporting device;

Accompanying drawing 12 is the top view of supporting device;

Accompanying drawing 13 is the front view of supporting device;

Accompanying drawing 14 is the structural representation of base;

Accompanying drawing 15 is the structural representation of support cover;

Accompanying drawing 16 is the structural representation of slider;

Accompanying drawing 17 is the structural representation of adjusting slider;

Accompanying drawing 18 is the structural representation of briquetting;

Accompanying drawing 19 is the structural representation of support bar briquetting block;

Accompanying drawing 20 is the structural representation of positioning screw;

Accompanying drawing 21 is the structural representation of positioning sleeve;

Accompanying drawing 22 is the structural representation of handle;

Accompanying drawing 23 is the structural representation of slider fixing plate. in:

1. Tension and compression fatigue specimen 2. High displacement amplifier 3. Guide chute 4. Supporting device 5. Bending fatigue specimen

6. Low power displacement amplifier 7. Connector 8. Lower connecting plate 9. Upper connecting plate 10. Transducer

11. Dowel bar 12. Backing plate 13. Static load boosting device 14. Isolation block 15. Pressure head

16. Press block 17. Adjustment slider 18. Longitudinal adjustment screw 19. Slider 20. Support cover

21. Positioning sleeve 22. Positioning screw 23. Handle 24. Base 25. Horizontal adjustment screw

26. Support bar pressing block 27. Support bar 28. Slider fixing plate 29. Support bar installation slot 30. Positioning screw installation slot

Detailed ways

This embodiment is an ultrasonic bending fatigue test device, which is used for a three-point bending fatigue test of metal materials at a frequency of 20 kHz, and can complete a bending fatigue test with a stress ratio R>0. According to the design of the connector and the low-magnification displacement amplifier in the ultrasonic bending fatigue test device, the stress amplitude loading range of the bending fatigue specimen is between 250-850 MPa. The ultrasonic bending fatigue specimen must meet the bending resonance condition of 20kHz, and the minimum length of the bending fatigue specimen should be greater than 30mm.

The ultrasonic bending fatigue test device includes a supporting device 4 , a bending fatigue sample 5 , a low-magnification displacement amplifier 6 , a connector 7 , a transducer 10 , a force transmitter, a static load adding device 13 , an isolation block 14 and an indenter 15 . The power transmission device is a frame structure composed of rods and plates, including a lower connecting plate 8, an upper connecting plate 9, a dowel rod 11, and a backing plate 12, and is located in the middle of this embodiment; the transducer 10 is located in the force transmitting inside the device. The flat plate at the top of the force transmitter is the backing plate 12 for installing the static load boosting device; the lower end of the transducer 10 is connected to the connector 7 through a screw, and the connector 7 passes through the lower connecting plate 8 and the upper connecting plate at the lower end of the force transmitting device 9, and connected with the low power displacement amplifier 6. The support device 4 is located below the low-magnification displacement amplifier 6 and is used to place the bending fatigue sample 5 . The static load boosting device is a mechanical tension and compression device, the force transmitter is connected to the static load boosting device, and the static load is loaded to the bending fatigue specimen through the force transmitter.

As shown in Figure 5. The connector 7 is an aluminum alloy revolving body, the outer circumference is stepped, and the outer diameter of the middle part is the largest, forming the flange of the connector 7; on both sides of the flange, there are lower connecting plates 8 and upper connecting plates with different outer diameters. Fitting section of plate 9. There are threaded holes in the center of the end faces of the two ends of the connector 7 respectively. The smaller end of the connector is screwed to the low-magnification displacement amplifier 6 through a screw, and the larger end is screwed to the transducer 10 through a screw. The transducer 10 is connected to the transducer 1 through a communication cable. The external ultrasonic generator is connected, and the geometric dimension of the connector 7 satisfies the resonance condition of 20 kHz vibration along the axial direction.

The power transmission device includes a lower connecting plate 8 , an upper connecting plate 9 , a dowel bar 11 and a backing plate 12 . Wherein, backing plate 12 is positioned at the top of power transmission device, and upper connection plate 9 and lower connection plate 8 are positioned at the lower end of power transmission device; Backing plate 12 and upper connection plate 9 and lower connection plate 8 are fixed by three dowel bars 11. even. The static load reinforcing device 13 passes through the center hole of the backing plate 12 and is fixedly connected with the backing plate 12 through nuts, so that the backing plate 12 is connected to the static load reinforcing device 13 .

The backing plate 12 is a circular plate with a through hole in the center. The lower connecting plate 8 and the upper connecting plate 9 are circular plates, and there is a through hole for installing the connector 7 in the center of the lower connecting plate 8 and the upper connecting plate 9, and the inner diameter of the connecting hole of the connector 7 is smaller than the middle part of the connector 7 The diameter of the flange on the outer circumference. The big end on one side of the flange of the connector 7 passes through the central hole of the upper connecting plate 9, and the small end on one side of the flange of the connector 7 passes through the central hole of the lower connecting plate 8, so that the flange in the middle of the connector 7 is positioned at the lower Between the connecting plate 8 and the upper connecting plate 9. Both ends of the dowel bar 11 have external threads; one end of the dowel bar 11 is fixedly connected to the backing plate 12 through the connecting hole on the edge of the backing plate 12, and the other end passes through the holes on the edge of the lower connecting plate 8 and the upper connecting plate 9 respectively. Three connecting holes and fixed with nuts.

As shown in Figure 10. The indenter 15 is a rod with an approximately tapered cross section. There is connecting screw hole in the middle part of pressure head 15 planes, by this connection screw hole, links to each other with the screw hole on the small end face of low power displacement amplifier 6 with screw rod, realizes the connection of pressure head 15 and low power displacement amplifier 6. The tapered tip of the indenter 15 is arc-shaped, and the arc-shaped tip of the cone is in contact with the bending fatigue sample 5 during the fatigue test.

As shown in Figure 9. The low-magnification displacement amplifier 6 is a rotating body made of titanium alloy material. According to the experimental requirements, the amplification factor of the low-magnification displacement amplifier is 6.3, and the geometric dimensions of the low-magnification displacement amplifier meet the resonance condition of 20kHz axial vibration. The outer circumference of the low-magnification displacement amplifier 6 is stepped; screw holes are processed in the center of both ends of the low-magnification displacement amplifier.

As shown in Figure 6. The three spacers 14 are all hollow rotating bodies, and are set on the dowel bars 11 between the lower connecting plate 8 and the upper connecting plate 9 . The inner diameter of the spacer block 14 is slightly larger than the outer diameter of the dowel bar 11, and when the spacer block 14 is set on the dowel bar 11, there is a clearance fit between the two. The height of the housing of the spacer block 14 is the same as the thickness of the flange of the connector 7 . When the dowel bar 11 is connected with the upper connecting plate 9 and the lower connecting plate 8, the upper connecting plate 9 and the lower connecting plate 8 are isolated and separated by the isolation block. The tolerance of the height of the spacer 14 relative to the thickness of the flange of the connector 7 is +0.1 mm, so as to ensure that the connector 7 can rotate between the upper connecting plate 9 and the lower connecting plate 8 .

The dowel rod 11 is a cylindrical long steel rod with threads processed at both ends. One end of the dowel rod passes through the small hole on the edge of the backing plate 12 and is connected to the backing plate 12 by a nut, and the other end passes through the upper connecting plate 9 successively. , Spacer block 14, lower connecting plate 8 are connected together by nuts. Before the dowel bar 11 is connected with the upper connection plate 9, the spacer 14, and the lower connection plate 8, the large and small ends of the connector 7 should be passed through the central holes of the upper connection plate 9 and the lower connection plate 8 respectively, so that the transmission When the force bar is connected with the connection plate, the flange of the connector 7 is fixed between the upper and lower two connection plates. After the relative positions of the connector 7, the upper connecting plate 9, the spacer 14, the lower connecting plate 8 and the backing plate 12 are determined, they are connected with the same 3 dowel bars.

As shown in Figure 11-13. The support device 4 is a symmetrical structure, including a pressure block 16, an adjustment slider 17, a longitudinal adjustment screw 18, a slider 19, a support cover 20, a positioning sleeve 21, a positioning screw 22, a handle 23, a base 24, and a horizontal adjustment screw 25 , Support bar pressing block 26, support bar 27 and slide block fixed plate 28. The supporting device 4 is installed on the test table of the static load adding device, and is located at the center of the test table. The positioning screw 22 passes through the central threaded holes of the two sliders 19 respectively, and is supported on the positioning screw mounting groove 30 across the table surface of the base 24 . The two sliders 19 are symmetrically installed in the guide chute 3 at the center of the table top of the base 24 , and the two adjustment sliders 17 are respectively located in the guide chute on the surface of the slider 19 . Two support covers 20 are respectively mounted on the two ends of the base 24 table, and the positioning screw 22 passes through the support seat formed by the semicircle at the lower end of the support cover 20 and the semicircular positioning screw mounting groove 30 at the two ends of the base table. After the initial positions of the two sliders 19 are determined, the position of the positioning screw 22 on the table top of the base 24 is determined by the positioning sleeve 21 . Two support bars 27 are placed respectively in the semicircular support bar installation grooves 29 on the two slide block decks, and the two ends of the support bars are respectively equipped with a briquetting block 16 and a support bar briquetting block 26, and the briquetting block 16 and the support bar briquetting block 26 will The support bar is fixed in the semicircle support bar installation groove 29 above the slide block. Longitudinal adjustment screws 18 pass through the screw holes in the middle of the adjustment slider 17 and are installed on the two adjustment sliders, and the horizontal adjustment screws 25 pass through the threaded holes in the middle of the pressure block 16 and are installed on the two pressure blocks. After the positions of the two sliders are determined, the sliders are respectively fixed on the base 24 by two slider fixing plates 28 .

As shown in Figure 14. Base 24 is welded by flat plate and the stand of a zigzag. There is a through hole in the middle of the base plate. The diameter of the through hole is the same as the diameter of the positioning shaft on the test table of the static load boosting device, and there is a clearance fit between the two; the U-shaped stand is located in the middle of the plate and above the through hole. There is guide chute 3 along this table top length direction in the center of the table top of U-shaped stand, is used for installing slide block 19, and makes slide block 19 slide in guide chute 3. There is a positioning block protruding from the inner surface of the guide chute 3 at the center of the guide chute 3 for determining the initial position of the slider. Both sides of the positioning block are guide chute 3 for installing the slide block 19, and the chute is connected to each other from the inside to the outside. The width of the guide chute 3 of the base 24 is the same as the width of the connecting block on the lower surface of the slide block 19, and the two are clearance fit. When the connecting block of the slide block 19 is placed in the guide chute 3, the sliding fit ; The positioning screw mounting groove 30 is arc-shaped, and its diameter is the same as the outer diameter of the positioning screw 22, and the two are clearance fits. The bottom plate of the base 24 is provided with a connecting hole for fixing the base with the test bench of the static load adding device.

As shown in Figure 16. Slide block 19 has two, is made up of mounting block and the connecting block perpendicular to it, and its profile is " T " font. The connecting block of the slide block 19 is located in the guide chute 3 of the base 24; the connecting block of the slide block 19 has a connecting hole through the positioning lead screw 22 of the connecting block. The mounting block surface of slide block 19 has the guide chute 3 that is used to install the adjustment slide block 17 parallel with the positioning screw 22 connecting holes on the connecting block of the slide block, and the center of the guide chute 3 is aligned with the positioning screw 22. The centers of the connection holes are on the same vertical plane. On one side of slide block 19 mounting block surface, also have guide chute 3 vertical circular arc support bar installation groove 29, be used to install support bar 27; The installation groove 29 of support bar 27 runs through the width direction of slide block 19 installation blocks.

As shown in Figure 20. There are two sections of incoherent external threads on the outer surface of the middle part of the positioning screw 22, and the two sections of external threads have opposite directions of rotation. After the two sections of threads of the positioning screw 22 are respectively connected with the two sliders 19, they are placed in the guide chute 3 of the base 24 together. When the positioning lead screw 22 is rotated, the two sliding blocks 19 move along the guide chute 3 in opposite directions respectively. The polished rods at both ends of the positioning screw are processed with screw holes for installing two positioning sleeves. One end of the positioning screw is connected with the handle 23. When assembling, screw the two sliders into the positioning lead screw 22, the connecting sections of the two sliders are respectively placed in the guide chute 3 in the base 24, and the positioning lead screw 22 is placed on the two semicircular positions on the base 24. In the mounting groove 30 of the shaped positioning screw, the slider is moved along the guide chute 3 in the base 24 by rotating the positioning screw. The rectangular slot above the slide block is used to install the adjustment slide block 17. The semicircle support bar installation groove 29 above the slide block is used to install the support bar 27. The position of the pin on the slider indicates the pin hole for installing the positioning pin, and the remaining 8 small holes are screw holes for installing fastening screws.

As shown in Figure 15. There are two support covers 20, both of which are rectangular grooved housings; there are semicircular positioning screw 22 holes in the center of the bottom edge of the support cover 20 in the length direction; There is a connection hole, and the connection hole corresponds to the screw hole on the base 24 . After the positioning lead screw 22 is connected with the slide block and placed in the guide chute 3 of the base 24 together, the support cover 20 is installed on the base 24 through connecting screws, and the semicircular groove on the lower surface of the support cover and the semi-circular groove on the upper surface of the base 24 The circular positioning screw mounting groove 30 constitutes a screw supporting seat supporting the positioning screw 22 to rotate freely, and is used for installing the positioning screw 22 .

As shown in Figure 21. There are two positioning sleeves 21, both of which are cylindrical shells with platforms processed on two sides, and positioning grooves are processed on the side platforms of the cylindrical shells. The inner hole of the positioning sleeve 21 is circular, and its aperture is the same as the outer diameter of the positioning screw 22, and the two are clearance fits. After the positioning screw 22, the slider 19 and the support cover 20 are installed, rotate the positioning screw to adjust the position of the slider so that the connecting blocks of the two sliders are respectively close to the two sides of the positioning block in the middle of the guide chute 3 of the base 24 , and determine the position of the slider at this time as the initial position. Put two positioning sleeves 21 into the two ends of the positioning screw 22 respectively, and make one end surface of the positioning sleeve 21 close to the side wall of the base 24, the limit screw passes through the positioning groove on the side of the positioning sleeve, and installs Into the screw hole on the positioning screw 22, limiting the axial movement of the positioning screw in the chute.

As shown in Figure 17. The adjustment slide block 17 is a block body. Adjust slide block 17 to have two, and its structure is identical, and direction is opposite. The adjustment slider 17 is a symmetrical structure, and its cross section is cross-shaped. Both sides of the horizontal block of the adjustment slider 17 respectively have an open slot through the thickness of the horizontal block; the adjustment slider 17 moves along the guide chute 3 above the slider 19, and when the position of the adjustment slider 17 is determined, tighten the screw The adjustment slider 17 is fixed on the slider through the opening slot, and the opening slot is symmetrical along the center of the adjustment slider 17 . In the middle part of the adjustment slider 17, there is a through threaded hole; the threaded hole cooperates with the longitudinal adjustment screw 18. Adjust the slide block 17 to slide along the rectangular groove on the slide block 19 to adjust the space for placing the bending fatigue sample.

As shown in Figure 18. The briquetting block 16 is a block. There are 2 briquetting blocks 16 . The middle part of the side of the briquetting block 16 has a through mounting hole for the horizontal adjusting screw 25; below the mounting hole of the lateral adjusting screw 25 and at the bottom of the side of the briquetting block 16, there is a semicircular groove for pressing the supporting bar 27 one end. There are two threaded holes on the upper surface of the pressure block 16 , the centerlines of the threaded holes are perpendicular to the centerlines of the mounting holes of the horizontal adjusting screw 25 , and are distributed on both sides of the mounting holes of the horizontal adjusting screw 25 . It is connected with the slider 19 through the threaded hole on the upper surface of the pressure block 16 .

As shown in Figure 19. There are also 2 block-shaped support bar pressing blocks 26, which are used to compress the other end of the support bar 27. The lower surface of the center of the support bar pressing block 26 has an arc-shaped groove cooperating with the pressing support bar 27 . There are two connection holes on the support bar pressing block 26, the center line of the connection hole is perpendicular to the center line of the compression support bar 27 compression grooves, and is distributed on both sides of the compression support bar 27 compression grooves, through the The connecting hole connects the support bar pressing block 26 with the slide block 19 .

As shown in Figure 23. The slider fixing plate 28 is a rectangular block with threaded holes in the middle for the connection between the slider fixing plate 28 and the slider 19 . After the position of the slider 19 is determined, pass the threaded hole in the middle part of the slider fixing plate 28 to be connected with the slider 19 with a fastening screw, and the slider 19 is fixed on the base 24 by the slider fixing plate.

Support bar 27 is installed in the support bar installation groove 29 on the slide block 19, and briquetting block 16, support bar briquetting block 26 fix the two ends of support bar respectively.

One end of the handle 23 is processed with a rectangular inner hole for connecting the positioning screw, and the handle 23 is helpful for the rotation of the positioning screw. The longitudinal adjustment screw 18 is installed in the screw hole in the middle of the adjustment slider 17. When the bending fatigue specimen 5 is installed, the longitudinal adjustment screw 18 is rotated to determine the longitudinal position of the specimen. The horizontal adjustment screw 25 is installed in the screw hole in the middle of the pressure block 16. When installing the bending fatigue sample, the horizontal adjustment screw is rotated to determine the lateral position of the sample.

During the ultrasonic bending fatigue test, first connect the force transducer together with the transducer 10, the connector 7, the low-magnification displacement amplifier 6, and the indenter 15 to the static load adding device, and then install the supporting part of the ultrasonic bending fatigue test device on the static On the experimental table of the load adding device 13, the bending fatigue sample 5 is placed on the support bar 27 of the supporting device 4; the position of the bending fatigue sample 5 is adjusted, and the connector 7 on the rotating force transmitter makes the pressure The cone tip of the head 15 is located on the center line of the bending fatigue sample 5, and the force can be added to start the fatigue test.

Claims (10)

1. a ultrasonic bending fatigue experimental device comprises low power displacement amplifier (6), connector (7) and transducer (10); The lower end of transducer (10) is connected by screw rod with connector (7); It is characterized in that, also comprise fulcrum arrangement (4) and force transmitters; And

A. transducer (10) is positioned at force transmitters; Force transmitters is positioned at the middle part of ultrasonic bending fatigue experimental device; Force transmitters comprises lower connecting plate (8), upper junction plate (9), transmission rod (11) and backing plate (12), and backing plate (12) is positioned at the top of force transmitters, and upper junction plate (9) and lower connecting plate (8) are positioned at the lower end of force transmitters; Be connected by three transmission rods (11) between backing plate (12) and upper junction plate (9) and the lower connecting plate (8); The lower connecting plate (8) that connector (7) one ends pass the force transmitters lower end is connected with low power displacement amplifier (6); The other end passes upper junction plate (9), is connected with transducer (10);

B. fulcrum arrangement (4) is positioned at low power displacement amplifier (6) below; Center pit and backing plate (12) that static load augmentor (13) passes backing plate (12) are connected;

C. fulcrum arrangement (4) is a symmetrical structure, comprises briquetting (16), adjusting slider (17), vertical set screw (18), slide block (19), supporting lid (20), abutment sleeve (21), location leading screw (22), handle (23), base (24), lateral adjustments screw (25), support strip briquetting (26), support strip (27) and slide block fixed head (28); The center that is installed in base (24) table top of two slide blocks (19) symmetry, two adjusting sliders (17) lay respectively in the chute on slide block (19) surface; Two supporting lids (20) lay respectively at the two ends of base (24) table top; Location leading screw (22) passes the location leading screw mounting groove that traverses the base table top, and by abutment sleeve (21) location; Support strip (27) is installed on the slide block (19), and briquetting (16), support strip briquetting (26) be the two ends of fixed bearing bar respectively.

2. a kind of according to claim 1 ultrasonic bending fatigue experimental device is characterized in that, spacing block (14) is sleeved on the transmission rod (11) between lower connecting plate (8) and the upper junction plate (9); Transmission rod one end is connected with backing plate (12), and it is fixing that the other end successively passes upper junction plate (9), spacing block (14) and lower connecting plate (8) back.

3. a kind of according to claim 1 ultrasonic bending fatigue experimental device is characterized in that there is the through hole that cooperates with the experiment table locating shaft at the base plate center of base (24); There is the guide chute (3) of slide block (19) at the table top center of base (24), the centre bit of guide chute (3) is equipped with the locating piece that protrudes the chute inside surface, in the both sides of locating piece, be guide chute that is used to install slide block (19) (3) and the location leading screw mounting groove (30) that is interconnected from inside to outside.

4. a kind of according to claim 1 ultrasonic bending fatigue experimental device is characterized in that, the contiguous block of slide block (19) is positioned at the guide chute (3) of base (24), and location leading screw (22) connecting hole is arranged on this contiguous block; There is the mounting groove of the adjusting slider (17) parallel with location leading screw (22) connecting hole on the contiguous block on the mounting blocks surface of slide block (19), and the center of the center of this mounting groove and location leading screw (22) connecting hole is on same vertical plane; The support strip mounting groove (29) vertical with adjusting slider (17) mounting groove arranged on slide block (19) mounting blocks surface on one side.

5. a kind of according to claim 1 ultrasonic bending fatigue experimental device is characterized in that, location leading screw (22) middle part outside surface has two sections external threads that rotation direction is opposite; Two sections external threads together are placed in the guide chute (3) of base (24) respectively with after a slide block (19) is connected; There is the mounting hole of abutment sleeve at leading screw two ends, location; The two ends of location leading screw (22) are set with abutment sleeve (21), and make an end face of abutment sleeve (21) be close to the sidewall of base (24); Stop screw passes the locating slot of abutment sleeve side, in the screw on the location leading screw (22) of packing into; Abutment sleeve (21) is by endoporus and location leading screw (22) clearance fit.

6. a kind of according to claim 1 ultrasonic bending fatigue experimental device is characterized in that, there is the via hole of semicircular location leading screw (22) at the center on supporting lid (20) base, both sides; There is connecting hole at cap surface two ends at supporting lid (20); When location leading screw (22) is connected in the guide chute (3) that also together is placed in base (24) with slide block after, to support lid (20) is fixed on the base (24), the half slot of lower surface and the semicircle location leading screw mounting groove (30) of base (24) upper surface are covered in supporting, have constituted the leading screw supporting base that supporting location leading screw (22) freely rotates.

7. a kind of according to claim 1 ultrasonic bending fatigue experimental device is characterized in that the both sides of adjusting slider (17) have open slot respectively, and this open slot is symmetrical in the center of adjusting slider (17), and the opening direction unanimity; There is the mounting hole of vertical set screw (18) at the center of adjusting slider (17).

8. a kind of according to claim 1 ultrasonic bending fatigue experimental device is characterized in that, the middle side edge of briquetting (16) has the mounting hole of lateral adjustments screw (25); In the below of lateral adjustments screw (25) mounting hole, the bottom of briquetting (16) side, have and compress the groove that support strip (27) cooperates; The both sides of briquetting (16) upper surface set screw (25) mounting hole, the connecting hole of the orthogonal slide block of center line (19) of own centre line and lateral adjustments screw (25) mounting hole.

9. a kind of according to claim 1 ultrasonic bending fatigue experimental device is characterized in that, the connecting hole on the support strip briquetting (26) is positioned at and compresses support strip (27) pressing groove both sides.

10. as a kind of ultrasonic bending fatigue experimental device as described in the claim 4, it is characterized in that, be slidingly matched between the guide chute (3) on slide block (19) and base (24) table top; The diameter of location leading screw mounting groove is with the external diameter of location leading screw (22).

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