Ultrasonic impact surface strengthening device and method

Abstract

The present invention discloses an ultrasonic impact surface strengthening device and method, the device includes a multi-station tool holder, a curved surface trajectory scanning module, a rotary platform, an ultrasonic impact module and a control device. Compared with the existing ultrasonic strengthening devices and methods, the present invention can improve the strengthening effect on the surface of parts. Based on the use of the curved surface trajectory scanning module to identify the contour of the special-shaped curved surface of the part, and combining the curved surface data information with the motion control of the rotary platform, the ultrasonic impact surface strengthening process is assisted, the rotation angle of the ultrasonic impact module is adjusted in real time and the impact direction is always kept perpendicular to the curved surface contour. The trajectory scanning and ultrasonic impact strengthening are carried out almost simultaneously, so that the impact force on the surface of the part is always a normal force, avoiding the adverse effects such as tangential force caused by the change in the contact angle between the impact head and the surface of the part, and improving the ultrasonic impact surface strengthening accuracy by combining the force feedback signal with the artificial intelligence deep learning method, so as to achieve a uniform and better strengthening effect.

Description

Technical Field

[0001] The invention relates to the technical field of ultrasonic surface strengthening, and in particular to an ultrasonic impact surface strengthening device and method. Background Art

[0002] Ultrasonic strengthening is a fatigue-resistant surface modification technology, which includes ultrasonic impact, ultrasonic rolling and other technical fields. Using high-power ultrasound as the driving energy, high-frequency ultrasonic vibration is applied to the tool head, so that ultrasonic energy is applied to the surface of the part, causing elastic-plastic deformation of the surface of the part, thereby introducing residual compressive stress and changing the surface microstructure. It can achieve the two purposes of finishing and surface strengthening at the same time, thus greatly improving the fatigue resistance and service life of the parts.

[0003] Most of the existing ultrasonic strengthening processes are applied to flat and cylindrical shaft parts, such as: ① The utility model patent with authorization announcement number CN209175201U discloses an ultrasonic rolling device for flat and outer cylindrical rolling, but it is only applicable to ultrasonic strengthening of regular outer surfaces; ② The invention patent with authorization announcement number CN109439885B discloses an ultrasonic impact device, which is also only applicable to ultrasonic impact treatment of flat and rotating parts with regular outer surfaces; ③ For the ultrasonic strengthening process of special-shaped curved parts, the utility model patent with authorization announcement number CN209954118U discloses a The ultrasonic rolling device for processing special-shaped surfaces adopts a flexible pneumatic joint clamp to drive the ball tool head to rotate in multiple directions, thereby realizing ultrasonic rolling processing of complex special-shaped surfaces of parts. However, this method fails to realize the scanning and recognition function of the trajectory of the special-shaped surface of the parts, and does not specifically describe the method of accurately controlling the real-time change of the rotation angle; ④ The invention patent with application publication number CN109465680A discloses a method for ultrasonic strengthening of the entire blade disk or blade profile, and the invention patent with application publication number CN108330264A discloses a trajectory-controllable surface strengthening device, and the invention patent with application publication number CN The invention patent No. 109015232A discloses a large-scale complex curved surface ultrasonic surface finishing and strengthening system and its use method; the above-mentioned invention patents mainly adopt the method of fixing the ultrasonic impact device to the spindle of the processing machine tool or the end effector of the industrial robot, and by using the control device of the processing machine tool or the rotary encoder or the robot motion trajectory controller, the vibration direction of the ultrasonic impact is always the normal direction of the workpiece surface, but the invention also fails to realize the scanning and recognition function of the trajectory of the special-shaped curved surface of the part; ⑤ The invention patent with the authorization announcement number CN102719637B discloses a method suitable for mechanized The built-in needle-type ultrasonic surface strengthening impact head is operated, and the impact needle is set in the guide hole on the guide sleeve. The guide sleeves respectively adopt flat end face guide sleeves, arc end face guide sleeves, and cone top small plane guide sleeves to perform ultrasonic strengthening treatment on flat surfaces, constant curvature surfaces, and arbitrary continuous curvature surfaces. However, for rotating parts with special-shaped curved surfaces, since their diameters along the axial direction gradually change, it is impossible to design a guide sleeve that is compatible with them. Cylindrical shafts of different diameters require matching guide sleeves of different sizes, which greatly increases the cost. At the same time, the invention also fails to realize the scanning and recognition function for the trajectory of the special-shaped curved surfaces of parts.

[0004] The above-mentioned patents all have limitations in actual production. Some even require a variety of guide devices to match the sizes of different processed parts, which has high production costs. In addition, the processing accuracy of the existing patents is unstable during the ultrasonic impact strengthening process. Summary of the invention

[0005] The purpose of the present invention is to provide an ultrasonic impact surface strengthening device and method, which can identify the surface contour of special-shaped curved parts, so that the impact force acting on the surface of the parts is always a normal force, thereby improving the ultrasonic impact surface strengthening accuracy and maintaining the stability of the strengthening accuracy during the processing process.

[0006] In order to achieve the above object, the solution of the present invention is:

[0007] An ultrasonic impact surface strengthening device comprises a multi-station tool holder, a curved surface trajectory scanning module, a rotary platform, an ultrasonic impact module and a control device; the multi-station tool holder can move along the X-axis and Z-axis directions; the curved surface trajectory scanning module and the rotary platform are respectively installed at different stations of the multi-station tool holder to achieve synchronous movement with the multi-station tool holder; the curved surface trajectory scanning module is used to scan the curved surface trajectory contour data of the part; the ultrasonic impact module is installed on the rotary platform, and the rotary platform can drive the ultrasonic impact module to perform rotational movement on the XOZ plane; the control device is used to control the curved surface trajectory scanning module and the rotary platform, and process data; when working, the control device receives the contour data and processes to obtain the curvature direction data, and according to the curvature direction data, adjusts the impact force direction by rotating the ultrasonic impact module through the rotary platform; the ultrasonic impact module collects the force feedback signal of the ultrasonic impact process in real time, and the control device performs artificial intelligence deep learning according to the contour data and the force feedback signal to adjust the impact force direction of the ultrasonic impact strengthening processing repeated multiple times in the future.

[0008] The surface trajectory recognition module is a laser measuring instrument. The multi-station tool holder moves along the Z-axis direction to adjust the distance between the laser measuring instrument and the surface of the part in real time, so that all the measured parts are located within the measuring area of ​​the laser measuring instrument during the measurement process. The multi-station tool holder moves along the X-axis direction so that the laser measuring instrument scans the surface of the part in sections to obtain segmented surface trajectory profile data.

[0009] The measurement accuracy of the laser measuring instrument is higher than 0.1 μm, and the maximum sampling frequency is set higher than 50 kHz.

[0010] The rotary platform comprises a fixed chassis mounted on the multi-station tool holder and a rotating disk pivotally connected to the fixed chassis. The rotating disk is pivotally connected to the fixed chassis via an internal ball bearing.

[0011] The ultrasonic impact module includes a transducer, a horn and an impact head connected in sequence, an ultrasonic generator electrically connected to the transducer, and a dynamometer arranged between the horn and the impact head; the transducer is installed on the rotating platform and is used to convert the input electrical power into mechanical power; the dynamometer is used to collect the force feedback signal of the ultrasonic impact process in real time, and determine whether the ultrasonic impact process is in a stable working state by analyzing the measured normal force and tangential force; the horn is used to amplify the particle displacement or velocity of the mechanical vibration and expand the ultrasonic amplitude; the ultrasonic generator is used to drive the transducer to work, and the generated mechanical energy provides high-frequency vibration for the impact head through the horn.

[0012] The impact head is a hard alloy ball with a diameter of 3-6 mm.

[0013] The dynamometer measures high dynamic force based on the principle of piezoelectric sensors, with a measurement range of -2~2kN and a natural frequency set higher than 50kHz; during the ultrasonic impact process, if the tangential force measured by the dynamometer exceeds 0.1N, it indicates that the ultrasonic impact direction is not perpendicular to the surface contour; if the normal force measured by the dynamometer increases or decreases suddenly, it indicates that the ultrasonic impact is in an unstable working state.

[0014] The ultrasonic impact surface strengthening device also includes a lathe chuck and a center, and a worktable; the lathe chuck and the center are used to clamp the special-shaped curved surface rotating parts and drive the special-shaped curved surface rotating parts to rotate; the worktable is used to fix the special-shaped curved surface planar parts by mechanical clamping and drive the special-shaped curved surface planar parts to rotate.

[0015] A method for strengthening a surface layer by ultrasonic impact, using the above-mentioned device for strengthening a surface layer by ultrasonic impact, comprises the following steps:

[0016] Step 1: Place the part to be processed on the corresponding processing platform to achieve rotational motion;

[0017] Step 2: Control the multi-station tool holder to move in linkage in the X-axis and Z-axis directions to drive the curved surface trajectory scanning module to move;

[0018] Step 3: The surface trajectory scanning module collects the surface trajectory profile data of the part at a set sampling frequency. During the measurement process, the part rotates at a set speed;

[0019] Step 4: The control device receives the curved surface trajectory profile data collected by the curved surface trajectory scanning module, processes the data and obtains the curvature direction data corresponding to the profile data, and then transmits the data to the rotary platform;

[0020] Step 5: Based on the received curvature direction data, the rotary platform rotates the ultrasonic impact module to ensure that the ultrasonic impact direction is always consistent with the curvature direction data;

[0021] Step 6: By controlling the starting point position of the impact point of the ultrasonic impact module in the Z-axis direction, the contact pressure between the surface of the parts is adjusted;

[0022] Step 7: The ultrasonic impact module collects the force feedback signal during the ultrasonic impact process in real time, and determines whether the working condition of the ultrasonic impact process is in a stable working state by analyzing the measured normal force and tangential force; and sends the force feedback signal to the control device; the control device performs artificial intelligence deep learning based on the contour data collected by the surface trajectory scanning module and the force feedback data collected by the ultrasonic impact module to adjust the impact force direction of subsequent repeated ultrasonic impact strengthening processing.

[0023] In the step 3, by adjusting the feed motion of the surface trajectory scanning module in the Z-axis direction, the distance between the surface trajectory scanning module and the surface of the part is adjusted in real time, so that all the measured parts are located within the measuring area of ​​the laser measuring instrument during the measurement process; at the same time, by adjusting the feed motion of the surface trajectory scanning module in the X-axis direction, the part is scanned in sections to obtain the segmented surface trajectory profile data, and transmit it to the control device.

[0024] After adopting the above technical scheme, the present invention can improve the strengthening effect on the surface of parts compared with the existing ultrasonic strengthening devices and methods. Based on the use of the curved surface trajectory scanning module to identify the contour of the special-shaped curved surface of the part, and combining the curved surface data information with the motion control of the rotary platform, the ultrasonic impact surface strengthening process is assisted, the rotation angle of the ultrasonic impact module is adjusted in real time and the impact direction is always kept perpendicular to the curved surface contour, so as to realize the working mode in which the trajectory scanning function and the ultrasonic impact strengthening function are implemented almost simultaneously, and at the same time, the impact force acting on the surface of the part is always a normal force, thereby avoiding the adverse effects such as tangential force caused by the change in the contact angle between the impact head and the surface of the part, and improving the ultrasonic impact surface strengthening accuracy by combining the force feedback signal with the artificial intelligence deep learning method, ensuring that the parts obtain a uniform and consistent strengthening layer and a better strengthening effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of a specific embodiment of the present invention;

[0026] Figure 2 It is a three-dimensional diagram of a rotary platform according to a specific embodiment of the present invention;

[0027] Figure 3 It is a working schematic diagram of machining a special-shaped curved surface rotating part according to a specific embodiment of the present invention;

[0028] Figure 4 It is a working schematic diagram of processing a planar part with a special-shaped curved surface according to a specific embodiment of the present invention;

[0029] Description of Figure Numbers:

[0030] Multi-station tool rest 1; rotary platform 2; fixed chassis 21; rotating disk 22; control device 3; laser measuring instrument 4; transducer 5; amplitude change rod 6; impact head 7; ultrasonic generator 8; dynamometer 9; lathe chuck 10; center 20; special-shaped curved surface rotating part 30; stage 40; special-shaped curved surface flat part 50. DETAILED DESCRIPTION

[0031] In order to further explain the technical solution of the present invention, the present invention is described in detail through specific embodiments. The 0 (origin), X-axis, and Z-axis directions in the following text are based on the 0 / X-axis / Z-axis indicated in the accompanying drawings, and refer to the relative directions to the surface of the part.

[0032] refer to Figures 1 to 4 As shown, the present invention includes an ultrasonic impact surface strengthening device, including a multi-station tool holder 1, a curved track scanning module, a rotary platform 2, an ultrasonic impact module and a control device 3.

[0033] The multi-station tool rest 1 can move along the X-axis and Z-axis directions;

[0034] The curved surface trajectory scanning module and the rotary platform 2 are respectively installed at different stations of the multi-station tool rest 1 to achieve synchronous movement with the multi-station tool rest 1; the curved surface trajectory scanning module is used to scan the curved surface trajectory profile data of the part;

[0035] The ultrasonic impact module is installed on the rotating platform 2, and the rotating platform 2 can drive the ultrasonic impact module to rotate around the B direction on the XOZ plane;

[0036] The control device 3 is used to control the curved track scanning module and the rotary platform 2, and process data;

[0037] During operation, the control device 3 receives contour data and processes it to obtain curvature direction data, and adjusts the direction of the impact force by rotating the ultrasonic impact module through the rotating platform 2 according to the curvature direction data; the ultrasonic impact module collects the force feedback signal of the ultrasonic impact process in real time, and the control device 3 performs artificial intelligence deep learning based on the contour data and the force feedback signal to adjust the impact force direction of subsequent repeated ultrasonic impact strengthening processing.

[0038] In the specific implementation example:

[0039] The above-mentioned curved surface trajectory recognition module is a laser measuring instrument 4. The multi-station tool holder 1 moves along the Z-axis direction to adjust the distance between the laser measuring instrument 4 and the surface of the part in real time, so that the measured parts are all located in the measurement area of ​​the laser measuring instrument 4 during the measurement process. The multi-station tool holder 1 moves along the X-axis direction to allow the laser measuring instrument 4 to scan the surface of the part in sections to obtain the segmented curved surface trajectory profile data. In this embodiment, the measurement accuracy of the laser measuring instrument 4 should be better than 0.1μm, and the maximum sampling frequency should be higher than 50kHz.

[0040] The rotary platform 2 comprises a fixed chassis 21 mounted on the multi-station tool holder 1 and a rotating plate 22 pivotally connected to the fixed chassis 21 . The rotating plate 22 is pivotally connected to the fixed chassis 21 via an internal ball bearing.

[0041] The ultrasonic impact module includes a transducer 5, a horn 6 and an impact head 7 connected in sequence, an ultrasonic generator 8 electrically connected to the transducer 5, and a dynamometer 9 arranged between the horn 6 and the impact head 7; the transducer 5 is installed on the rotary platform 2, and is used to convert the input electrical power into mechanical power; the dynamometer 9 is used to collect the force feedback signal of the ultrasonic impact process in real time, and determine whether the ultrasonic impact process is in a stable working state by analyzing the measured normal force and tangential force; the horn 6 is used to amplify the particle displacement or velocity of the mechanical vibration and expand the ultrasonic amplitude; the ultrasonic generator 8 is used to drive the transducer 5 to work, and the generated mechanical energy provides high-frequency vibration for the impact head 7 through the horn 6. In this embodiment, the impact head 7 is a hard alloy ball with a diameter of 3~6mm; the main structure of the transducer 5 is a tightly combined piezoelectric ceramic stack; the dynamometer 9 measures high dynamic force based on the principle of piezoelectric sensor, with a measurement range of -2~2kN, and the natural frequency should be higher than 50kHz. The dynamometer 9 collects the force feedback signal of the ultrasonic impact process in real time. By analyzing the measured normal force and tangential force, it can be known whether the working condition of the ultrasonic impact process is in a stable working state, thereby further improving the surface strengthening accuracy. During the ultrasonic impact process, if the tangential force measured by the dynamometer 9 exceeds 0.1N, it indicates that the ultrasonic impact direction and the surface contour are not perpendicular to each other; if the normal force measured by the dynamometer 9 increases or decreases suddenly, it indicates that the ultrasonic impact is in an unstable working state. After completing the first ultrasonic impact strengthening treatment, artificial intelligence deep learning is carried out with the help of the contour data collected by the laser measuring instrument 4 and the force feedback data collected by the dynamometer 9, so as to provide higher accuracy guarantee for the subsequent repeated ultrasonic impact strengthening processing.

[0042] See also Figure 3 The present invention is used for processing a special-shaped curved surface rotating part 30, wherein the special-shaped curved surface rotating part 30 refers to a shaft-like part with cylindrical ends and a certain curvature in the middle.

[0043] During operation, the emission direction of the laser measuring instrument 4 is adjusted to the positive direction of the Z axis, and the surface profile of the special-shaped curved surface rotating part 30 can be measured; the multi-station tool holder 1 is controlled to be linked in the X-axis and Z-axis directions, thereby driving the movement of the laser measuring instrument 4. By adjusting the feed movement of the laser measuring instrument 4 in the Z-axis direction, the distance between the laser measuring instrument 4 and the surface of the part is adjusted in real time, so that all the geometric features of the measured part are located within the measurement area of ​​the laser measuring instrument 4.

[0044] The lathe chuck 10 drives the irregular curved surface rotating part 30 to rotate around the C direction at a speed of 500 rpm, and the laser measuring instrument 4 moves from the outer end surface of the irregular curved surface rotating part 30 along the negative direction of the X axis at a feed speed of 0.1 mm / r. The laser measuring instrument 4 scans the irregular curved surface rotating part 30 in small sections step by step at a set sampling frequency of 20 kHz, obtains the contour data of each small section of the curved surface trajectory, and transmits it to the motion control device 3.

[0045] The motion control device 3 receives the contour data of each small segment of the curved surface trajectory collected by the laser measuring instrument 4 through its PLC electronic control system, obtains the curvature direction of the small segment contour after data processing, and then transmits the curvature direction data information of the small segment contour to the rotary platform 2 through the PLC electronic control system.

[0046] The rotary platform 2 is installed on a station of the multi-station tool rest 1 and can move along the X-axis and Z-axis directions with the multi-station tool rest 1.

[0047] The rotary platform 2 and its control device 3 are based on the curvature direction of each small segment of the received contour, so that the ultrasonic impact direction is always consistent with the curvature direction of each small segment of the contour through rotational motion, thereby realizing a working mode in which the trajectory scanning function and the ultrasonic impact strengthening function are almost implemented simultaneously, and the surface strengthening accuracy for special-shaped curved surface parts is improved. The ultrasonic generator 8 is set to provide a high-frequency vibration frequency signal of 28kHz, and the axial vibration is realized through the transducer 5, and the amplitude amplification effect of the horn 6 is used to generate an ultrasonic amplitude of 20μm, and finally the high-frequency and high-amplitude vibration is transmitted to the impact head 7, so as to apply ultrasonic impact to the parts.

[0048] During the ultrasonic impact process, the lathe chuck 10 drives the special-shaped curved surface rotating part 30 to rotate at a speed of 500rpm. By controlling the starting point position of the impact head 7 in the Z-axis direction, the contact pressure between the impact head 7 and the surface of the part can be adjusted, and the pre-pressure value is set to 1300N. The ultrasonic impact module (transducer 5, amplitude rod 6, impact head 7) installed on the rotary platform 2 moves based on the curvature direction of each small segment of the obtained contour, and the impact head 7 moves from the outer end face of the special-shaped curved surface rotating part 30 along the negative direction of the X-axis at a feed speed of 0.1mm / r. The rotation of the rotary platform 2 around the B direction can ensure that the direction of the ultrasonic impact is always perpendicular to the contour of the curved surface trajectory.

[0049] The dynamometer 9 collects the force feedback signal in the ultrasonic impact process in real time at a set sampling frequency of 50kHz. By analyzing the measured normal force and tangential force, it can be known whether the working condition of the ultrasonic impact process is in a stable working state, which further improves its surface strengthening accuracy. During the ultrasonic impact process, if the tangential force measured by the dynamometer 9 exceeds 0.1N, it indicates that the ultrasonic impact direction and the surface contour are not perpendicular to each other; if the normal force measured by the dynamometer 9 increases or decreases suddenly, it indicates that the ultrasonic impact is in an unstable working state. After completing the first ultrasonic impact strengthening treatment, artificial intelligence deep learning is carried out with the help of the contour data collected by the laser measuring instrument 4 and the force feedback data collected by the dynamometer 9, so as to provide higher accuracy guarantee for the subsequent repeated ultrasonic impact strengthening processing.

[0050] During the ultrasonic impact process, the method can realize a working mode in which the trajectory scanning function and the ultrasonic impact strengthening function are implemented almost simultaneously, and the scanning measurement and ultrasonic impact strengthening paths are set to start from one end of the part to near the terminal end of the part, and finally the scanning measurement and ultrasonic impact strengthening areas cover the entire surface contour of the part, thereby realizing the ultrasonic impact strengthening effect on the surface of the special-shaped curved surface rotating part 30.

[0051] See also Figure 4 When the present invention is used to process a special-shaped curved surface plane part 50, it also includes a stage 40, which is used to fix the special-shaped curved surface plane part 50 by mechanical clamping, so that the center line of the special-shaped curved surface plane part 50 and the center line of the stage 40 are kept coincident as much as possible, and the main shaft drives the stage 40 and the special-shaped curved surface plane part 50 to rotate around the D direction. Among them, the special-shaped curved surface plane part 50 refers to a disc-like part with a certain spherical surface in the middle.

[0052] The laser measuring instrument 4 is installed on a station of the multi-station tool holder 1, and the emission direction of the laser is adjusted to be along the positive direction of the Z axis, so that the surface profile of the special-shaped curved surface planar part 50 can be measured.

[0053] The multi-station tool holder 1 is controlled to move in the X-axis and Z-axis directions, thereby driving the laser measuring instrument 4 to move. By adjusting the feed movement of the laser measuring instrument 4 in the Z-axis direction, the distance between the laser measuring instrument 4 and the surface of the part is adjusted in real time, so that all the geometric features of the measured part are located within the measuring area of ​​the laser measuring instrument 4.

[0054] The stage 40 drives the irregular curved surface plane part 50 to rotate at a speed of 500 rpm, and the laser measuring instrument 4 moves from the outer end surface of the irregular curved surface plane part 50 along the X-axis direction at a feed speed of 0.1 mm / r. The laser measuring instrument 4 scans the irregular curved surface plane part 50 in small sections step by step at a set sampling frequency of 20 kHz, obtains the contour data of each small section of the curved surface trajectory, and transmits it to the motion control device 3.

[0055] The motion control device 3 receives the contour data of each small segment of the curved surface trajectory collected by the laser measuring instrument 4 through its PLC electronic control system, obtains the curvature direction of the small segment contour after data processing, and then transmits the curvature direction data information of the small segment contour to the rotary platform 2 through the PLC electronic control system.

[0056] The rotary platform 2 is installed on a station of the multi-station tool rest 1 and can move along the X-axis and Z-axis directions with the multi-station tool rest 1.

[0057] The rotary platform 2 and its control device 3 are based on the curvature direction of each small segment of the received contour, so that the ultrasonic impact direction is always consistent with the curvature direction of each small segment of the contour through rotational motion, thereby realizing a working mode in which the trajectory scanning function and the ultrasonic impact strengthening function are almost implemented simultaneously, and the surface strengthening accuracy for special-shaped curved surface parts is improved. The ultrasonic generator 8 is set to provide a high-frequency vibration frequency signal of 28kHz, and the axial vibration is realized through the transducer 5, and the amplitude amplification effect of the horn 6 is used to generate an ultrasonic amplitude of 20μm, and finally the high-frequency and high-amplitude vibration is transmitted to the impact head 7, so as to apply ultrasonic impact to the parts.

[0058] During the ultrasonic impact process, the stage 40 rotates the irregular curved surface planar part 50 at a speed of 500 rpm. By controlling the starting point position of the impact head 7 in the Z-axis direction, the contact pressure between the impact head 7 and the surface of the part can be adjusted, and the pre-pressure value is set to 1300N. The ultrasonic impact module (transducer 5, amplitude rod 6, impact head 7) installed on the rotating platform 2 moves based on the curvature direction of each small segment of the obtained contour, and the impact head 7 moves from the outer end face of the irregular curved surface planar part 50 along the X-axis direction at a feed speed of 0.1mm / r. The rotation of the rotating platform 2 around the B direction can ensure that the ultrasonic impact direction is always perpendicular to the curved surface trajectory contour.

[0059] The dynamometer 9 collects the force feedback signal in the ultrasonic impact process in real time at a set sampling frequency of 50kHz. By analyzing the measured normal force and tangential force, it can be known whether the working condition of the ultrasonic impact process is in a stable working state, which further improves its surface strengthening accuracy. During the ultrasonic impact process, if the tangential force measured by the dynamometer 9 exceeds 0.1N, it indicates that the ultrasonic impact direction and the surface contour are not perpendicular to each other; if the normal force measured by the dynamometer 9 increases or decreases suddenly, it indicates that the ultrasonic impact is in an unstable working state. After completing the first ultrasonic impact strengthening treatment, artificial intelligence deep learning is carried out with the help of the contour data collected by the laser measuring instrument 4 and the force feedback data collected by the dynamometer 9, so as to provide higher accuracy guarantee for the subsequent repeated ultrasonic impact strengthening processing.

[0060] During the ultrasonic impact process, the method can realize a working mode in which the trajectory scanning function and the ultrasonic impact strengthening function are implemented almost simultaneously, and the scanning measurement and ultrasonic impact strengthening paths are set to start from one end of the part to the center line of the part, and finally the scanning measurement and ultrasonic impact strengthening areas cover the entire surface contour of the part, thereby realizing the ultrasonic impact strengthening effect on the surface of the special-shaped curved surface planar part 50.

[0061] The present invention also includes a method for strengthening the surface layer by ultrasonic impact, comprising the following steps:

[0062] Step 1: Place the part to be processed on the corresponding processing platform to achieve rotational motion;

[0063] Step 2: Control the multi-station tool holder 1 to move in linkage in the X-axis and Z-axis directions to drive the curved surface trajectory scanning module to move;

[0064] Step 3: The surface trajectory scanning module collects the surface trajectory profile data of the part at a set sampling frequency. During the measurement process, the part rotates at a set speed;

[0065] Step 4: the control device 3 receives the curved surface trajectory profile data collected by the curved surface trajectory scanning module, processes the data and obtains the curvature direction data corresponding to the profile data, and then transmits it to the rotary platform 2;

[0066] Step 5: Based on the received curvature direction data, the rotary platform 2 rotates the ultrasonic impact module to ensure that the ultrasonic impact direction is always consistent with the curvature direction data, and realizes a working mode in which the trajectory scanning function and the ultrasonic impact strengthening function are implemented almost simultaneously;

[0067] Step 6: By controlling the starting point position of the impact point of the ultrasonic impact module in the Z-axis direction, the contact pressure between the surface of the parts is adjusted;

[0068] Step 7: The ultrasonic impact module collects the force feedback signal during the ultrasonic impact process in real time, and determines whether the working condition of the ultrasonic impact process is in a stable working state by analyzing the measured normal force and tangential force; and sends the force feedback signal to the control device 3; the control device 3 performs artificial intelligence deep learning based on the contour data collected by the surface trajectory scanning module and the force feedback data collected by the ultrasonic impact module, so as to adjust the impact force direction of subsequent repeated ultrasonic impact strengthening processing.

[0069] In the above step 3, by adjusting the feed movement of the surface trajectory scanning module in the Z-axis direction, the distance between the surface trajectory scanning module and the part surface is adjusted in real time, so that all the measured parts are located within the measurement area of ​​the laser measuring instrument during the measurement process; at the same time, by adjusting the feed movement of the surface trajectory scanning module in the X-axis direction, the parts are scanned in sections to obtain segmented surface trajectory profile data, and transmit it to the control device 3.

[0070] Through the above scheme, the present invention can improve the strengthening effect on the surface of parts compared with the existing ultrasonic strengthening devices and methods. Based on the use of the curved surface trajectory scanning module to identify the contour of the special-shaped curved surface of the part, and combining the curved surface data information with the motion control of the rotary platform, the ultrasonic impact surface strengthening process is assisted, the rotation angle of the ultrasonic impact module is adjusted in real time and the impact direction is always kept perpendicular to the curved surface contour, so as to realize the working mode in which the trajectory scanning function and the ultrasonic impact strengthening function are implemented almost simultaneously, and at the same time, the impact force acting on the surface of the part is always a normal force, thereby avoiding the adverse effects such as tangential force caused by the change in the contact angle between the impact head and the surface of the part, and improving the ultrasonic impact surface strengthening accuracy by combining the force feedback signal with the artificial intelligence deep learning method, ensuring that the parts obtain a uniform and consistent strengthening layer and a better strengthening effect.

[0071] The above embodiments and drawings do not limit the product form and style of the present invention. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present invention.

Claims

1. An ultrasonic impact surface strengthening device, characterized in that: It includes a multi-station tool holder, a curved surface trajectory scanning module, a rotary platform, an ultrasonic impact module and a control device; The multi-station tool rest can move along the X-axis and Z-axis directions; The curved surface trajectory scanning module and the rotary platform are respectively installed at different stations of the multi-station tool holder to achieve synchronous movement with the multi-station tool holder; the curved surface trajectory scanning module is used to scan the curved surface trajectory profile data of the part; The ultrasonic impact module is mounted on the rotating platform, and the rotating platform can drive the ultrasonic impact module to rotate on the XOZ plane; The control device is used to control the curved track scanning module and the rotary platform, and process data; During operation, the control device receives the contour data and processes to obtain the curvature direction data, and adjusts the impact force direction by rotating the ultrasonic impact module through the rotary platform according to the curvature direction data; the ultrasonic impact module collects the force feedback signal of the ultrasonic impact process in real time, and the control device performs artificial intelligence deep learning according to the contour data and the force feedback signal to adjust the impact force direction of the subsequent repeated ultrasonic impact strengthening processing; The surface trajectory recognition module is a laser measuring instrument. The multi-station tool holder moves along the Z-axis direction to adjust the distance between the laser measuring instrument and the surface of the part in real time, so that all the measured parts are located within the measurement area of ​​the laser measuring instrument during the measurement process. The multi-station tool holder moves along the X-axis direction so that the laser measuring instrument scans the surface of the part in sections to obtain the segmented surface trajectory profile data. The ultrasonic impact module includes a transducer, a horn and an impact head connected in sequence, an ultrasonic generator electrically connected to the transducer, and a dynamometer arranged between the horn and the impact head; the transducer is installed on the rotating platform and is used to convert the input electrical power into mechanical power; the dynamometer is used to collect the force feedback signal of the ultrasonic impact process in real time, and determine whether the ultrasonic impact process is in a stable working state by analyzing the measured normal force and tangential force; the horn is used to amplify the particle displacement or velocity of the mechanical vibration and expand the ultrasonic amplitude; the ultrasonic generator is used to drive the transducer to work, and the generated mechanical energy provides high-frequency vibration for the impact head through the horn.

2. The ultrasonic impact surface strengthening device according to claim 1, characterized in that: The measurement accuracy of the laser measuring instrument is higher than 0.1 μm, and the maximum sampling frequency is set higher than 50 kHz.

3. The ultrasonic impact surface strengthening device according to claim 1, characterized in that: The rotary platform comprises a fixed chassis mounted on the multi-station tool holder and a rotating disk pivotally connected to the fixed chassis. The rotating disk is pivotally connected to the fixed chassis via an internal ball bearing.

4. The ultrasonic impact surface strengthening device according to claim 1, characterized in that: The impact head is a hard alloy ball with a diameter of 3-6 mm.

5. The ultrasonic impact surface strengthening device according to claim 1, characterized in that: The dynamometer measures high dynamic forces based on the principle of piezoelectric sensors, with a measurement range of -2~2kN and a natural frequency setting higher than 50kHz; During the ultrasonic impact process, if the tangential force measured by the dynamometer exceeds 0.1N, it indicates that the ultrasonic impact direction is not perpendicular to the curved surface profile; if the normal force measured by the dynamometer increases or decreases suddenly, it indicates that the ultrasonic impact is in an unstable working state.

6. The ultrasonic impact surface strengthening device according to any one of claims 1 to 5, characterized in that: Also included are the lathe chuck and center, as well as the stage; The lathe chuck and the center are used to clamp the special-shaped curved surface rotating parts and drive the special-shaped curved surface rotating parts to rotate; The stage is used to fix the special-shaped curved surface planar part by mechanical clamping, and drive the special-shaped curved surface planar part to perform rotational motion.

7. A method for strengthening a surface layer by ultrasonic impact, using an ultrasonic impact surface strengthening device as claimed in any one of claims 1 to 6, characterized in that The following steps are involved: Step 1: Place the part to be processed on the corresponding processing platform to achieve rotational motion; Step 2: Control the multi-station tool holder to move in linkage in the X-axis and Z-axis directions to drive the curved surface trajectory scanning module to move; Step 3: The surface trajectory scanning module collects the surface trajectory profile data of the part at a set sampling frequency. During the measurement process, the part rotates at a set speed; Step 4: The control device receives the curved surface trajectory profile data collected by the curved surface trajectory scanning module, processes the data and obtains the curvature direction data corresponding to the profile data, and then transmits the data to the rotary platform; Step 5: Based on the received curvature direction data, the rotary platform rotates the ultrasonic impact module to ensure that the ultrasonic impact direction is always consistent with the curvature direction data; Step 6: By controlling the starting point position of the impact point of the ultrasonic impact module in the Z-axis direction, the contact pressure between the surface of the parts is adjusted; Step 7: The ultrasonic impact module collects the force feedback signal during the ultrasonic impact process in real time, and determines whether the working condition of the ultrasonic impact process is in a stable working state by analyzing the measured normal force and tangential force; and sends the force feedback signal to the control device; the control device performs artificial intelligence deep learning based on the contour data collected by the surface trajectory scanning module and the force feedback data collected by the ultrasonic impact module to adjust the impact force direction of subsequent repeated ultrasonic impact strengthening processing.

8. The method for strengthening the surface layer by ultrasonic impact as claimed in claim 7, characterized in that: In the step 3, by adjusting the feed motion of the surface trajectory scanning module in the Z-axis direction, the distance between the surface trajectory scanning module and the surface of the part is adjusted in real time, so that all the measured parts are located within the measuring area of ​​the laser measuring instrument during the measurement process; at the same time, by adjusting the feed motion of the surface trajectory scanning module in the X-axis direction, the part is scanned in sections to obtain the segmented surface trajectory profile data, and transmit it to the control device.

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