Test device and test method for track interference behavior in ultrasonic impact strengthening

Abstract

The present invention relates to the technical field of ultrasonic surface strengthening. Provided are a test device and test method for a track interference behavior in ultrasonic impact strengthening. The device comprises an object table, an X-Y-Z-axis motion control module and a workpiece rotation motion module being provided on the object table, and the workpiece rotation motion module being suitable for clamping a workpiece and driving the workpiece to rotate. The X-Y-Z-axis motion control module is connected to an ultrasonic impact strengthening execution module, an extending end of an air cylinder is connected to an ultrasonic transducer, and a booster is connected to the ultrasonic transducer so as to convert an input electric power into a mechanical power and enable same to act on the booster. A rolling head is connected to the tail end of the booster. A dynamometer is provided between the ultrasonic transducer and the booster for measuring a static pressure acting on the workpiece in real time, and feeding the static pressure back to a control system, such that the rolling head keeps a constant static pressure on the workpiece. The solution can improve the strengthening effect on surfaces of parts.

Description

Ultrasonic impact strengthening trajectory interference behavior testing device and testing method Technical Field

[0001] The present invention relates to the technical field of ultrasonic surface strengthening, and in particular to a device and method for testing ultrasonic impact strengthening trajectory interference behavior. Background Art

[0002] Ultrasonic strengthening is a fatigue-resistant surface modification technology encompassing ultrasonic impact and ultrasonic rolling. Using high-power ultrasound as the driving energy, high-frequency ultrasonic vibrations are applied to the tool head, thereby applying ultrasonic energy to the surface of the part. This causes elastic-plastic deformation of the surface, introducing residual compressive stress and changing the surface microstructure. This simultaneously achieves both finishing and surface strengthening, significantly improving the fatigue resistance and service life of the part. However, some existing ultrasonic strengthening devices have some shortcomings. For example, patent No. CN209954120U discloses an ultrasonic vibration rolling processing device with a simple structure that can only perform ultrasonic rolling on individual workpieces. Patent No. CN111805167A discloses an ultrasonic rolling device with stable output and adjustable gap. This ultrasonic rolling device achieves controllable ball gap by adding an adjustment ring between the pressure cap and the fixed cover. However, due to the large forces generated during the rolling process, it cannot effectively ensure the rotation of the ball. Patent number CN206509687U discloses an ultrasonic vibration rolling device, which transmits an ultrasonic frequency signal to a transducer through an ultrasonic generator. The transducer converts the signal into mechanical vibration, which is amplified by a horn and performs ultrasonic frequency extrusion vibration on the roller and the workpiece being processed. However, due to the unknown impact force, in experiments, it is very likely that the surface quality of the workpiece after processing will be uneven.

[0003] Ultrasonic impact strengthening (UASP) has been widely used in the processing of small components, achieving significant results in improving material properties and extending component life. However, current equipment and processes have limitations for large components and those with complex curved surfaces. In fields such as aerospace, in particular, the demand for strengthening large components is growing. Traditional UASP equipment often cannot effectively process these components, severely restricting their application and performance improvement during production.

[0004] Summary of the Invention

[0005] The present invention discloses a device for testing the interference behavior of ultrasonic impact strengthening tracks, aiming to improve the problem that traditional ultrasonic impact strengthening equipment often cannot meet the requirements for effectively processing large components.

[0006] The present invention adopts the following scheme:

[0007] The present application provides an ultrasonic impact strengthening trajectory interference behavior testing device, including a stage, on which an XYZ axis motion control module and a workpiece rotation motion module are provided, and the workpiece rotation motion module is suitable for clamping the workpiece and driving the workpiece to rotate; the XYZ axis motion control module is connected to an ultrasonic impact strengthening execution module, and the ultrasonic impact strengthening execution module includes a cylinder, an ultrasonic transducer, a horn, and a rolling head, wherein the protruding end of the cylinder is connected to the ultrasonic transducer, and the horn is connected to the ultrasonic transducer to convert the input electric power The ultrasonic transducer is converted into mechanical power and acts on the amplitude variable rod; the end of the amplitude variable rod is connected to a rolling head to amplify the particle displacement of the mechanical vibration and provide high-frequency vibration for the rolling head to apply ultrasonic rolling strengthening effect to the surface of the workpiece from the side; a dynamometer is provided between the ultrasonic transducer and the amplitude variable rod to detect the static pressure acting on the workpiece in real time, the dynamometer is electrically connected to the XYZ-axis motion control module and feeds back the measured static pressure data to the XYZ-axis motion control module to adjust and compensate the position and posture of the rolling head, so that the rolling head maintains a constant static pressure on the workpiece.

[0008] Furthermore, the workpiece rotation motion module includes a chuck and a pin device arranged on a slide rail, wherein the chuck is connected to a first drive motor to drive the chuck to rotate, and the pin device is provided with a second drive motor to drive the pin device to slide on the slide rail to tighten the workpiece fixed on the chuck.

[0009] Furthermore, the force gauge is also connected to a signal amplifier and a data acquisition card. The force gauge is suitable for collecting the static pressure applied to the material and converting it into an electrical signal. The amplifier is suitable for amplifying the electrical signal and transmitting it to the data acquisition card. The data acquisition card acquires the electrical signal and converts it into a digital signal.

[0010] Furthermore, the XYZ-axis motion control module includes a linear motor, a belt drive module and a lifting platform. The lifting platform controls the ultrasonic shock strengthening execution module to move in the Z-axis direction, so that the center line of the rolling head and the rotation axis of the workpiece are always kept at the same height; the belt drive module controls the ultrasonic shock strengthening execution module to move in the Y-axis direction, so that the ultrasonic shock strengthening execution module approaches and moves away from the workpiece; the linear motor controls the ultrasonic shock strengthening execution module to feed in the X-axis direction, and sets the corresponding feed speed in combination with the preset spindle speed and trajectory coverage to obtain different motion trajectories.

[0011] The present invention also provides a method for testing the interference behavior of ultrasonic impact strengthening tracks, using any of the above-mentioned ultrasonic impact strengthening track interference behavior testing devices, comprising the following steps:

[0012] S1: Use the workpiece rotation motion module to fix the workpiece; adjust the initial position of the rolling head and perform CNC programming according to the trajectory interference requirements;

[0013] S2: Drive the workpiece to start rotating; start the ultrasonic generator to make the rolling head generate high-frequency vibration; start the belt transmission module to control the ultrasonic impact strengthening execution module to move on the Y axis. After the rolling head contacts the workpiece, start the linear motor to control the ultrasonic impact strengthening execution module to move on the X axis according to the preset feed amount;

[0014] S3: Track interference is achieved by coordinating the workpiece rotation speed with the rolling head feed speed. The ultrasonic generator provides a high-frequency vibration frequency signal of 20-30kHz, and the ultrasonic transducer realizes axial vibration. The amplitude amplification effect of the horn is used to transmit the high-frequency and high-amplitude vibration to the rolling head, thereby exerting ultrasonic impact on the part.

[0015] S4: The belt drive module is controlled by the data fed back from the dynamometer to control the movement of the rolling head along the Y-axis to adjust the contact pressure between the rolling head and the workpiece surface to be constant; the ultrasonic impact strengthening effect on the workpiece along the axial length is achieved by controlling the movement of the X-axis;

[0016] S5: The force exerted by the rolling head on the workpiece during the strengthening process is collected and detected in real time by a dynamometer, and the force is analyzed through data processing.

[0017] Furthermore, in step S1 , the feed speed of the rolling head along the axial direction of the workpiece is determined by the spindle speed, amplitude, static pressure and coverage.

[0018] Furthermore, in step S1, the rolling head is aligned before rolling, the rolling head is moved close to the workpiece surface, copper foil is placed between the workpiece and the rolling head and moved up and down, and when there is obvious resistance, the X-axis starting point is set to the workpiece diameter, and the rolling head is moved to the vicinity of the workpiece end face to set the Z-axis 0 point to complete the alignment.

[0019] Furthermore, during the rolling strengthening process, a coolant is used to cool the workpiece rolling head.

[0020] Furthermore, the positioning accuracy of the rolling head along the axial movement of the workpiece is higher than 0.1 μm.

[0021] Furthermore, the workpiece is cut before rolling to ensure that the surface roughness of the workpiece is less than 0.8 μm and the axial runout is controlled within IT2 level. Beneficial effects:

[0022] The device provided by this invention incorporates a dynamometer between the ultrasonic transducer and the horn, enabling real-time monitoring and acquisition of static pressure and friction between the rolling head and the workpiece. The dynamometer feeds the static pressure acting on the workpiece back to the control system, which uses the Y-axis belt drive module to adjust and compensate the position and posture of the rolling head to maintain a constant static pressure. This design effectively improves the accuracy and efficiency of ultrasonic rolling strengthening, providing a superior solution for machining large components. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 is a schematic structural diagram of an ultrasonic impact strengthening trajectory interference behavior testing device according to an embodiment of the present invention;

[0024] FIG2 is a schematic diagram of a workpiece after strengthening in a device for testing trajectory interference behavior of ultrasonic impact strengthening according to an embodiment of the present invention;

[0025] FIG3 is a schematic diagram of track coverage on a workpiece of an ultrasonic impact strengthening track interference behavior testing device according to an embodiment of the present invention;

[0026] FIG4 is a schematic structural diagram of an ultrasonic impact strengthening trajectory interference behavior testing device according to an embodiment of the present invention when a rolling head is in contact with a workpiece;

[0027] FIG5 is a first experimental trajectory diagram of an experiment on a Ti-6Al-4V specimen using ultrasonic impact strengthening trajectory interference behavior according to an embodiment of the present invention;

[0028] FIG6 is a second experimental trajectory diagram of an experiment on a Ti-6Al-4V specimen using ultrasonic impact strengthening trajectory interference behavior according to an embodiment of the present invention;

[0029] 7 is a third experimental trajectory diagram of an experiment on a Ti-6Al-4V specimen using ultrasonic impact strengthening trajectory interference behavior according to an embodiment of the present invention;

[0030] Figure numerals: stage 1; belt drive module 2; Y-axis slide 3; X-axis guide rail 4; Z-axis lifting platform 5; cylinder 6; ultrasonic transducer 7; dynamometer 8; amplitude rod 9; rolling head 10; ejector pin 11; handwheel 12; linear motion module 13; first drive motor 141; X-axis drive motor 142; Y-axis drive motor 143; second drive motor 144; chuck 15; workpiece 16. DETAILED DESCRIPTION

[0031] Example 1

[0032] In conjunction with Figures 1 to 4, this embodiment provides an ultrasonic impact strengthening trajectory interference behavior testing device, including a stage 1, on which an XYZ-axis motion control module and a workpiece 16 rotation motion module are provided, and the workpiece 16 rotation motion module is suitable for clamping the workpiece 16 and driving the workpiece 16 to rotate; the XYZ-axis motion control module is connected to an ultrasonic impact strengthening execution module, and the ultrasonic impact strengthening execution module includes a cylinder 6, an ultrasonic transducer 7, a variable amplitude rod 9, and a rolling head 10, wherein the protruding end of the cylinder 6 is connected to the ultrasonic transducer 7, and the variable amplitude rod 9 is connected to the ultrasonic transducer 7 to output The input electrical power is converted into mechanical power and acts on the amplitude transformer 9; the end of the amplitude transformer 9 is connected to a rolling head 10 to amplify the particle displacement of the mechanical vibration and provide high-frequency vibration to the rolling head 10 to apply ultrasonic rolling strengthening effect to the surface of the workpiece 16 from the side; a dynamometer 8 is provided between the ultrasonic transducer 7 and the amplitude transformer 9 to detect the static pressure acting on the workpiece 16 in real time, and the dynamometer 8 is electrically connected to the XYZ-axis motion control module and feeds back the measured static pressure data to the XYZ-axis motion control module to adjust and compensate the position and posture of the rolling head 10, so that the rolling head 10 maintains a constant static pressure on the workpiece 16.

[0033] As shown in Figures 1 and 4 , in this embodiment, the shape of the workpiece 1 is not specifically limited. The XYZ-axis motion control module and the workpiece 16 rotational motion module are mounted on the workpiece 1. The ultrasonic impact strengthening execution module includes a cylinder 6, an ultrasonic transducer 7, a horn 9, and a rolling head 10. The ultrasonic transducer 7 converts input electrical power into mechanical power, which is applied to the horn 9. The horn 9 amplifies the displacement or velocity of the mechanical vibration particles to increase the ultrasonic amplitude and provide high-frequency vibration for the rolling head 10. The rolling head 10 uses a high-hardness carbide ball with a diameter of 4-7 mm. A force gauge 8 is sandwiched between the ultrasonic transducer 7 and the horn 9, enabling real-time detection of the pressure acting on the workpiece 16. The transducer's primary structure is a tightly coupled piezoelectric ceramic stack that converts input electrical power into mechanical power. An ultrasonic generator is connected to the transducer's piezoelectric ceramic stack, driving the ultrasonic transducer 7. The generated mechanical energy, through the tightly coupled horn 9, provides high-frequency vibration for the impact rolling head 10.

[0034] Specifically, the XYZ-axis motion control module includes a linear motor, a belt drive module 2, and a lifting platform. The lifting platform controls the ultrasonic impact strengthening execution module to move in the Z-axis direction, so that the center line of the rolling head 10 and the rotation axis of the workpiece 16 are always kept at the same height; the belt drive module 2 controls the ultrasonic impact strengthening execution module to move in the Y-axis direction, so that the ultrasonic impact strengthening execution module approaches and moves away from the workpiece 16; the linear motor controls the ultrasonic impact strengthening execution module to feed in the X-axis direction, and sets the corresponding feed speed in accordance with the preset spindle speed and track coverage to obtain different motion trajectories. The Z-axis lifting platform 5 is connected to the X-axis guide rail 4 through a connecting plate; the X-axis guide rail 4 is connected to the Y-axis slide 3, and the X-axis motion is realized by the X-axis drive motor 142. Here, the linear motor, belt drive module 2, and lifting platform are connected to the same control system for coordinated control through the control system. Here, the X-axis displacement accuracy should be better than 0.002mm, the Y-axis displacement accuracy should be better than 0.005mm, and the Z-axis displacement accuracy should be better than 0.001mm.

[0035] The workpiece 16 rotary motion module includes a chuck 15 and an ejector 11 device disposed on a slide rail, wherein the chuck 15 is connected to a first drive motor 141 to drive the chuck 15 to rotate, and the ejector 11 device is provided with a second drive motor 14 to drive the ejector 11 device to slide on the slide rail to tighten the workpiece 16 fixed to the chuck 15. The chuck 15 here can be a three-jaw chuck 15, the tail end of which is connected to the first drive motor 141 to drive the round rod-shaped workpiece 16 clamped on the three-jaw chuck 15 to rotate. A slide rail is provided below the ejector 11 device, and the ejector 11 device includes a slide seat and an ejector 11 fixed to the slide seat. The ejector 11 is also provided with a manual wheel to drive the ejector 11 to move along the axis to achieve a fine-tuning function. Here, the slide is connected to the second drive motor 14 through the linear motion module 13 to move linearly on the slide rail, thereby pressing the ejector pin 11 against the end of the workpiece 16 to keep the workpiece 16 stable, while ensuring that the axis of the ejector pin 11 and the axis of the three-jaw chuck 15 are on the same axis.

[0036] The dynamometer 8 is also connected to a signal amplifier and a data acquisition card. The dynamometer 8 is suitable for collecting the static pressure applied to the material and converting it into an electrical signal. The amplifier is suitable for amplifying the electrical signal and transmitting it to the data acquisition card. The data acquisition card acquires the electrical signal and converts it into a digital signal. Here, the dynamometer 8 is connected to the rolling head 10. The main function of the dynamometer 8 is to convert the force applied to the workpiece 16 into an electrical signal, amplify the weak electrical signal output by the dynamometer 8 to an appropriate range through the amplifier, and finally convert the amplified electrical signal into a digital signal through the data acquisition card, and sample and store it for subsequent data processing and analysis; on the other hand, the dynamometer 8 can collect the static pressure acting on the workpiece 16 in real time and feed it back to the computer control system. The position and posture of the rolling head 10 are adjusted and compensated by the Y-axis belt drive module 2 to maintain a constant static pressure, ultimately achieving more accurate processing parameters, more uniform surface strengthening, more stable processing process and higher processing efficiency.

[0037] In one embodiment, when the present device is used to process a rod-shaped workpiece 16, the rod-shaped workpiece 16 is first fixed by the three-jaw chuck 15 and the ejector pin 11. The workpiece 16 is first pre-tightened by the three-jaw chuck 15, and the handwheel 12 is turned to move the ejector pin 11 along the axis until it contacts the workpiece 16. Finally, the three-jaw chuck 15 is clamped and the ejector pin 11 is fixed. The X-axis drive motor 142 is turned on to drive the ultrasonic rolling module to move along the X-axis until the center of the rolling head 10 is approximately 1 to 3 mm away from the surface of the rod-shaped workpiece 16. The lifting platform is then adjusted along the Z-axis until the center of the rolling head 10 is on the same horizontal plane as the axis of the three-jaw chuck 15 and the ejector pin 11. The X-axis drive motor 142 is started to move the ultrasonic rolling module along the X-axis to the initial ultrasonic impact strengthening position and set it to X0.0. The Y-axis drive motor 143 is started to fine-tune the Y-axis position so that the rolling head 10 is in contact with the surface of the workpiece 16, and the Y position is set to the diameter of the workpiece 16, which is defined as the 0 point. Before starting the ultrasonic rolling device, the ultrasonic rolling module is kept away from the surface of the workpiece 16 .

[0038] When exploring the ultrasonic rolling interference experiment (for example: the coverage rate is 50%), the ultrasonic rolling module is driven to move so that the rolling head 10 contacts the surface of the rod-shaped workpiece 16 and presses into the workpiece 16. The static pressure applied can be known by the dynamometer 8. Turn on the first drive motor 141 to drive the rod-shaped workpiece 16 to rotate at a certain speed. The ultrasonic impact strengthening feed rate is set according to the speed, the diameter of the workpiece 16 and the track width. The ultrasonic generator is set to provide a high-frequency vibration signal of 27kHz (not limited to this), and the vibration signal is converted into axial vibration through the ultrasonic transducer, and the amplitude amplification effect of the amplitude transformer 9 is used to generate an ultrasonic amplitude of about 4μm, and finally the high-frequency vibration is transmitted to the rolling head 10, thereby applying an ultrasonic rolling strengthening effect to the surface of the rod-shaped workpiece 16.

[0039] Compared with the existing ultrasonic impact strengthening devices and methods, the present invention can improve the surface strengthening effect of the specimen. The trajectory interference method can achieve high-precision processing of the material surface, and can more conveniently detect surface defects and deformation problems, thereby improving the quality and performance of the material. By adopting the trajectory interference method, it is possible to optimize and adjust the different process parameters in the ultrasonic rolling strengthening device. Compared with the traditional ultrasonic rolling method of changing the feed rate, the trajectory interference method can further understand the surface deformation law during the processing process, thereby achieving accurate optimization of the process parameters, and further improving the surface integrity and service performance of the specimen after strengthening treatment.

[0040] Example 2

[0041] The present invention also provides a method for testing the interference behavior of ultrasonic impact strengthening tracks, using any of the above-mentioned ultrasonic impact strengthening track interference behavior testing devices, comprising the following steps:

[0042] S1: Use the workpiece 16 rotational motion module to secure the workpiece 16; adjust the initial position of the rolling head 10 and perform CNC programming based on the trajectory interference requirements. CNC programming allows for precise control of motion speed, thereby controlling trajectory interference. By programming, parameters such as feed rate and spindle speed can be specified to precisely control the motion trajectory. Furthermore, the dynamometer 8 can collect the static pressure acting on the workpiece 16 in real time and feed it back to the computer. The Y-axis belt drive adjusts and compensates the position and posture of the rolling head to maintain a constant static pressure, thereby ensuring the accuracy of the friction force obtained during the ultrasonic impact strengthening process.

[0043] S2: Drive the workpiece 16 to start rotating; start the ultrasonic generator to make the rolling head 10 generate high-frequency vibration; start the belt transmission module 2 to control the ultrasonic impact strengthening execution module to move on the Y axis. After the rolling head 10 contacts the workpiece 16, start the linear motor to control the ultrasonic impact strengthening execution module to move on the X axis according to the preset feed amount;

[0044] S3: Track interference is achieved by coordinating the rotation speed of the workpiece 16 with the feed speed of the rolling head 10. The ultrasonic generator provides a high-frequency vibration frequency signal of 20-30kHz, and axial vibration is achieved through the ultrasonic transducer 7. The amplitude amplification effect of the horn 9 is used to transmit the high-frequency, high-amplitude vibration to the rolling head 10, thereby applying ultrasonic impact to the part;

[0045] S4: The belt drive module 2 is controlled by the data fed back by the dynamometer 8 to control the rolling head 10 to move along the Y-axis to adjust the contact pressure between the rolling head 10 and the surface of the workpiece 16 to be constant; the ultrasonic impact strengthening effect on the workpiece 16 along the axial length is achieved by controlling the X-axis movement;

[0046] S5: The force exerted by the rolling head 10 on the workpiece 16 during the strengthening process is collected and detected in real time by the dynamometer 8, and the force is analyzed by data processing.

[0047] As shown in Figure 2, the trajectory interference method described above determines the feed amount based on the required coverage and spindle speed, amplitude, and static pressure to form a feed trajectory. It can be set according to user needs to interfere with the trajectory; the feed speed is determined by calculating the single-turn indentation width and coverage. In addition to being affected by the spindle speed, amplitude, static pressure, and coverage, the axial feed amount of the tool head along the specimen also depends on the size of the indenter. Here, the spindle speed is defined as n, the amplitude is defined as A, the static pressure is defined as F, the indenter diameter is defined as R, the width of the enhanced trajectory is defined as L, and the depth is defined as H; the radial feed speed of the tool head along the specimen can be calculated based on the coverage C:

[0048] In this embodiment, the coverage is used to characterize the degree of interference, and the coverage is defined as:

[0049] Wherein, C is the coverage, s is the interference width, and L is the width of the enhanced track. The radial feed speed f of the rolling head 10 along the specimen can be obtained according to the spindle speed: f=(LS)*n.

[0050] In the above step S1, the rolling head 10 is tool-set before rolling: the rolling head 10 is moved close to the surface of the workpiece 16, and copper foil is placed between the workpiece 16 and the rolling head 10 to move up and down. When there is obvious resistance, the starting point of the X-axis is set to the diameter of the workpiece 16, and the rolling head 10 is moved to the vicinity of the end face of the workpiece 16 and set as the Z-axis 0 point to complete the tool-set. It should be noted that during the rolling strengthening process, coolant is required to cool the rolling head 10 of the workpiece 16. In this embodiment, the positioning accuracy of the rolling head 10 along the axial movement of the workpiece 16 is higher than 0.1μm. Furthermore, the workpiece 16 is cut before rolling so that the surface roughness of the workpiece 16 is less than 0.8μm, and the axial runout is controlled within the IT2 level.

[0051] According to this embodiment, the following experiments were conducted on Ti-6Al-4V specimens using ultrasonic impact strengthening trajectory interference behavior:

[0052] (1) Under the conditions of spindle speed of 50 rad / min, amplitude of 4 μm, and static pressure of 75 N, as the coverage increases, the friction force between the rolling head 10 and the specimen changes. The relevant experimental results are shown in Figure 5;

[0053] (2) Under the conditions of spindle speed of 75 rad / min, amplitude of 4 μm, and static pressure of 75 N, as the coverage increases, the friction force between the rolling head 10 and the test piece changes. The relevant experimental results are shown in Figure 6;

[0054] (3) Under the conditions of spindle speed of 100 rad / min, amplitude of 4 μm, and static pressure of 75 N, as the coverage increases, the friction force between the rolling head 10 and the test piece changes. The relevant experimental results are shown in Figure 7.

[0055] By comparing the above ultrasonic shock strengthening trajectory interference experiments, the following conclusions were drawn:

[0056] 1. In the case of coverage, the friction force of the first track is lower than that of the second track at different scratching speeds. This is because the material accumulates at both ends during the first sliding of the indenter, and the material accumulates seriously in front of the indenter during the second sliding.

[0057] 2. The friction force of the second track gradually decreases with the increase of coverage, which is due to the decrease of material accumulation effect with the increase of coverage.

[0058] 3. The friction force does not change much after the coverage exceeds 85%.

[0059] Therefore, the above-mentioned embodiment method can be used to study the interference behavior of ultrasonic impact strengthening under different spindle speeds, different coverages, different amplitudes, and different static pressures. Since it is continuous ultrasonic impact strengthening, the friction force signal between the indenter and the specimen can be accurately and stably collected, and the static pressure acting on the workpiece 16 can be collected in real time by the dynamometer 8 and fed back to the computer. The position and posture of the rolling head 10 are adjusted and compensated by the Y-axis belt drive module to maintain a constant static pressure. The method provided in this embodiment can be used to study the optimization of feed rate during ultrasonic impact strengthening, and can provide a reference for force control adjustment in the strengthening of large components and curved surfaces, so as to achieve surface integrity while improving processing efficiency. The relevant test results can be used for in-depth research on the mechanism of high-energy composite surface modification technology, optimize ultrasonic impact strengthening processing parameters, and improve product quality.

[0060] It should be understood that the above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention.

[0061] The above description of the drawings used in the implementation manner only shows certain embodiments of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without making any creative efforts.

Claims

1. An ultrasonic impact strengthening trajectory interference behavior testing device, comprising a stage, on which an XYZ axis motion control module and a workpiece rotation motion module are provided, characterized in that: The workpiece rotation motion module is suitable for clamping the workpiece and driving the workpiece to rotate; the XYZ-axis motion control module is connected to an ultrasonic impact strengthening execution module, which includes a cylinder, an ultrasonic transducer, a variable amplitude rod, and a rolling head, wherein the protruding end of the cylinder is connected to the ultrasonic transducer, and the ultrasonic transducer is connected to the variable amplitude rod to convert the input electrical power into mechanical power and act on the variable amplitude rod; the end of the variable amplitude rod is connected to the rolling head to amplify the particle displacement of the mechanical vibration and provide high-frequency vibration for the rolling head to apply ultrasonic rolling strengthening effect to the workpiece surface from the side; a dynamometer is arranged between the ultrasonic transducer and the variable amplitude rod to detect the static pressure acting on the workpiece in real time, and the dynamometer is electrically connected to the XYZ-axis motion control module and feeds back the measured static pressure data to the XYZ-axis motion control module to adjust and compensate the position and posture of the rolling head, so that the rolling head maintains a constant static pressure on the workpiece.

2. The ultrasonic impact strengthening trajectory interference behavior testing device according to claim 1, characterized in that: The workpiece rotary motion module includes a chuck and a pin device arranged on a slide rail, wherein the chuck is connected to a first drive motor to drive the chuck to rotate, and the pin device is provided with a second drive motor to drive the pin device to slide on the slide rail to tighten the workpiece fixed on the chuck.

3. The ultrasonic impact strengthening trajectory interference behavior testing device according to claim 1, characterized in that: The force gauge is also connected to a signal amplifier and a data acquisition card. The force gauge is suitable for collecting the static pressure applied to the material and converting it into an electrical signal. The amplifier is suitable for amplifying the electrical signal and transmitting it to the data acquisition card. The data acquisition card acquires the electrical signal and converts it into a digital signal.

4. The ultrasonic impact strengthening trajectory interference behavior testing device according to claim 1, characterized in that: The XYZ-axis motion control module includes a linear motor, a belt drive module and a lifting platform. The lifting platform controls the ultrasonic impact strengthening execution module to move in the Z-axis direction, so that the center line of the rolling head and the rotation axis of the workpiece are always kept at the same height; the belt drive module controls the ultrasonic impact strengthening execution module to move in the Y-axis direction, so that the ultrasonic impact strengthening execution module approaches and moves away from the workpiece; the linear motor controls the ultrasonic impact strengthening execution module to feed in the X-axis direction, and sets the corresponding feed speed in accordance with the preset spindle speed and trajectory coverage to obtain different motion trajectories.

5. A method for testing the interference behavior of ultrasonic impact strengthening trajectory, characterized in that: The ultrasonic impact strengthening trajectory interference behavior testing device according to any one of claim 4 comprises the following steps: S1: Use the workpiece rotation motion module to fix the workpiece; adjust the initial position of the rolling head and perform CNC programming according to the trajectory interference requirements; S2: Drive the workpiece to start rotating; start the ultrasonic generator to make the rolling head generate high-frequency vibration; start the belt transmission module to control the ultrasonic impact strengthening execution module to move on the Y axis. After the rolling head contacts the workpiece, start the linear motor to control the ultrasonic impact strengthening execution module to move on the X axis according to the preset feed amount; S3: Track interference is achieved by coordinating the workpiece rotation speed with the rolling head feed speed. The ultrasonic generator provides a high-frequency vibration frequency signal of 20-30kHz, and the ultrasonic transducer realizes axial vibration. The amplitude amplification effect of the horn is used to transmit the high-frequency and high-amplitude vibration to the rolling head, thereby exerting ultrasonic impact on the part. S4: The belt drive module is controlled by the data fed back by the dynamometer to control the rolling head to move along the Y axis. The contact pressure between the rolling head and the workpiece surface is adjusted to remain constant; the ultrasonic impact strengthening effect on the workpiece along the axial length is achieved by controlling the X-axis movement; S5: The force exerted by the rolling head on the workpiece during the strengthening process is collected and detected in real time by a dynamometer, and the force is analyzed through data processing.

6. The method for testing the interference behavior of ultrasonic impact strengthening tracks according to claim 5, characterized in that: In step S1 , the feed speed of the rolling head along the axial direction of the workpiece is determined by the spindle speed, amplitude, static pressure and coverage.

7. The method for testing the interference behavior of ultrasonic impact strengthening tracks according to claim 5, characterized in that: In step S1, the rolling head is aligned before rolling. The rolling head is moved close to the workpiece surface. Copper foil is placed between the workpiece and the rolling head and moved up and down. When there is obvious resistance, the X-axis starting point is set to the workpiece diameter. The rolling head is moved to the vicinity of the workpiece end face and the Z-axis 0 point is set to complete the tool alignment.

8. The method for testing the interference behavior of ultrasonic impact strengthening tracks according to claim 5, characterized in that: During the rolling strengthening process, coolant is used to cool the workpiece rolling head.

9. The method for testing the interference behavior of ultrasonic impact strengthening tracks according to claim 5, characterized in that: The positioning accuracy of the rolling head along the axial movement of the workpiece is higher than 0.1 μm.

10. The method for testing the interference behavior of ultrasonic impact strengthening tracks according to claim 5, characterized in that: The workpiece is cut before rolling to ensure that the surface roughness of the workpiece is less than 0.8μm and the axial runout is controlled within IT2 level.

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