A rolling device and surface hardening apparatus

Abstract

The application discloses a rolling device and a surface strengthening device, and relates to the technical field of workpiece processing. The rolling device comprises a loading mechanism, a transmission mechanism, at least one floating rolling unit, a contact state detection unit and a control mechanism. The loading mechanism is used for adjusting an output load according to a loading adjustment signal. The transmission mechanism is in transmission connection with the loading mechanism. The floating rolling unit is movably connected to the transmission mechanism and is used for rolling contact with a surface to be rolled of a workpiece. The contact state detection unit is used for outputting a contact state signal representing a contact state between the floating rolling unit and the surface to be rolled of the workpiece. The control mechanism determines a rolling load value according to the contact state signal and adjusts the output load of the loading mechanism according to a difference between the rolling load value and a target rolling load value. The rolling device can reduce actual rolling load fluctuation, make the pressure degree of different processing areas consistent, and improve the stability and consistency of rolling processing quality.

Description

Technical Field

[0001] This application relates to the field of workpiece processing technology, and in particular to a rolling device and a surface strengthening equipment. Background Technology

[0002] Roller burnishing is a surface finishing technique that uses rolling contact to apply pressure to the surface of a workpiece. It can improve the surface quality of the workpiece while inducing plastic deformation of the surface layer, thereby increasing surface hardness, wear resistance, and fatigue resistance. Roller burnishing strengthening technology has been increasingly applied to the surface strengthening of shafts and ring-shaped parts.

[0003] Existing roller burnishing devices typically use rollers, balls, or other rollers to create rolling contact with the workpiece surface to be burned, subjecting the surface to repeated compression to achieve surface strengthening or shaping. Most current devices apply loads to the rollers using a preset loading force, with the burnishing load primarily determined by rigid displacement or the set value of the pressure system. However, in actual roller burnishing, the workpiece surface may have shape errors or dimensional fluctuations, workpiece clamping may also deviate, and the process is further affected by factors such as vibration and thermal deformation. These factors cause fluctuations in the actual burnishing load between the rollers and the surface to be burned, leading to inconsistent pressure levels in different processing areas and affecting the consistency and stability of the burnishing quality. Summary of the Invention

[0004] The purpose of this application is to provide a rolling device and a surface strengthening equipment, which solves the problem that fluctuations in the actual rolling load between the rolling part and the surface to be rolled cause inconsistent pressure in different processing areas, thereby affecting the consistency and stability of the rolling process quality.

[0005] To achieve the above objectives, this application provides a rolling device for rolling the surface of a workpiece to be rolled, comprising: The loading mechanism includes a loading control unit and a loading output unit. The loading mechanism adjusts the output load of the loading output unit according to the loading adjustment signal input to the loading control unit. The transmission mechanism is connected to the loading output unit via a transmission connection; At least one floating rolling unit is movably connected to the transmission mechanism for rolling contact with the workpiece surface to be rolled during the rolling process; A contact state detection unit, connected to at least one of the floating rolling unit and the transmission mechanism, is used to output a contact state signal, which characterizes the contact state between the floating rolling unit and the workpiece surface to be rolled. The control mechanism has its input end connected to the contact state detection unit and its output end connected to the loading control unit. It is used to determine the rolling load value based on the contact state signal and to output a loading adjustment signal to the loading control unit based on the difference between the rolling load value and the target rolling load value.

[0006] In some embodiments, an elastic support unit is further included, which is disposed between the floating rolling unit and the transmission mechanism, and is used to elastically deform when the floating rolling unit moves relative to the transmission mechanism.

[0007] In some embodiments, at least one floating rolling unit is a plurality of floating rolling units, the plurality of floating rolling units are arranged at intervals around the transmission mechanism, and each floating rolling unit is provided with an elastic support unit between itself and the transmission mechanism. The floating rolling unit includes a rolling seat and rolling elements. The rolling seat is movably connected to the transmission mechanism, and the rolling elements are rotatably disposed on the rolling seat. The elastic support unit is an elastic compression component, which is located between the rolling base and the transmission mechanism, and the extension and retraction direction of the elastic compression component is parallel to the movement direction of the rolling base.

[0008] In some embodiments, the contact state signal characterizes at least one of the relative displacement of the floating rolling unit with respect to the transmission mechanism, the deformation of the elastic support unit, or the force exerted on the floating rolling unit during rolling.

[0009] In some embodiments, the transmission mechanism includes a conversion input section and a conversion output section. The conversion input section is connected to the loading output section, and the floating rolling unit is connected to the conversion output section. Both the loading output section and the conversion input section are movably arranged along a first direction, and the conversion output section is movably arranged along a second direction, which intersects with the first direction. The conversion input section has a first force transmission surface, and the conversion output section has a second force transmission surface that contacts the first force transmission surface. Both the first force transmission surface and the second force transmission surface are inclined relative to the first direction.

[0010] In some embodiments, the rolling device has a device axis, a first direction parallel to the device axis, and a second direction radial relative to the device axis; the conversion input is a conical drive member, the conversion output is an annular expansion member, the first force transmission surface is a first conical surface disposed on the conical drive member, and the second force transmission surface is a second conical surface disposed on the annular expansion member.

[0011] In some embodiments, a loading state detection unit is further included. The loading state detection unit is connected to the loading mechanism and outputs a loading state signal. The control mechanism determines a first load value based on the contact state signal, determines a second load value based on the loading state signal, and determines a rolling load value based on the first load value and the second load value.

[0012] In some embodiments, the system further includes a position acquisition unit and a storage unit. The position acquisition unit outputs a position signal, which represents the processing position of the floating rolling unit on the workpiece surface to be rolled. The control mechanism associates the contact state signal, the rolling load value, and the position signal to generate position load data and stores it in the storage unit. When the position difference between the current processing position represented by the position signal and the processing position recorded in the position load data reaches a preset lead amount, the control mechanism corrects the loading adjustment signal according to the position load data.

[0013] In some embodiments, the loading mechanism is a fluid pressure loading mechanism, the loading output part is a piston rod, and the loading control part includes a pressure regulating element connected to the output end of the control mechanism. The control mechanism adjusts the output load of the piston rod through the pressure regulating element.

[0014] This application also provides a surface strengthening apparatus, including a CNC machine tool and a rolling device as described in any of the above claims, wherein the CNC machine tool includes a workpiece clamping mechanism for mounting a workpiece and a rolling clamping mechanism for mounting the rolling device.

[0015] Compared to the aforementioned background technology, the rolling device provided in this application embodiment is used for rolling processing of the surface of a workpiece to be rolled, including a loading mechanism, a transmission mechanism, a contact state detection unit, a control mechanism, and at least one floating rolling unit. The loading mechanism includes a loading control unit and a loading output unit, and adjusts the output load of the loading output unit according to a loading adjustment signal input to the loading control unit. The transmission mechanism is drivenly connected to the loading output unit. At least one floating rolling unit is movably connected to the transmission mechanism for rolling contact with the surface of the workpiece to be rolled during rolling processing. The contact state detection unit is connected to at least one of the floating rolling unit and the transmission mechanism, and outputs a contact state signal, which characterizes the contact state between the floating rolling unit and the surface of the workpiece to be rolled. The input end of the control mechanism is connected to the contact state detection unit, and the output end is connected to the loading control unit. It determines the rolling load value based on the contact state signal and outputs a loading adjustment signal to the loading control unit based on the difference between the rolling load value and the target rolling load value.

[0016] The beneficial effects of this type of rolling device mainly include: In the rolling device of this application, the loading mechanism can change the output load of the loading output unit according to the loading adjustment signal. The transmission mechanism transmits the output load to the floating rolling unit, so that the floating rolling unit forms rolling contact with the workpiece surface to be rolled during the rolling process. Since the floating rolling unit is movably connected to the transmission mechanism, when the contact state changes due to shape error, dimensional fluctuation, clamping deviation, processing vibration or thermal deformation on the workpiece surface to be rolled, the floating rolling unit can generate a movement or force change related to the contact state change relative to the transmission mechanism. The contact state detection unit outputs a contact state signal accordingly. The control mechanism determines the rolling load value according to the contact state signal, compares the rolling load value with the target rolling load value, and then outputs a loading adjustment signal to the loading control unit according to the difference between the two, so that the loading mechanism corrects the output load of the loading output unit. Therefore, this application forms a feedback adjustment process of contact state detection, rolling load determination, load difference comparison, and output load adjustment, which enables the rolling device to actively adjust the rolling load according to the actual contact state, reduce the fluctuation of the actual rolling load caused by workpiece error and processing disturbance, and make the pressure degree of different processing areas of the surface to be rolled tend to be consistent, thereby improving the stability and consistency of rolling processing quality. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the rolling device in the embodiments of this application.

[0019] Figure 2 for Figure 1 A cross-sectional view of the rolling device shown.

[0020] Figure 3 for Figure 1 The diagram shows the distribution of floating rolling units in the rolling device.

[0021] Figure 4 for Figure 1 The diagram shows the structure of the floating rolling unit in the rolling device.

[0022] Figure 5 for Figure 4 The cross-sectional view of the floating rolling unit shown.

[0023] Figure 6 This is a schematic diagram of the surface strengthening device in the embodiments of this application.

[0024] Figure 7 for Figure 6 Enlarged schematic diagram of the machining section.

[0025] in: 10-Loading mechanism; 11-Loading control unit; 12-Loading output unit; 20 - Transmission mechanism; 21 - Conversion input section; 211 - First force transmission surface; 22 - Conversion output section; 221 - Second force transmission surface; 30 - Floating rolling unit; 31 - Rolling seat; 32 - Rolling element; 40 - Contact status detection unit; 50 - Control mechanism; 60 - Elastic support unit; 70 - Flange connection; 80-Cage; 90-Workpiece; 100-CNC machine tool; 110 - Workpiece clamping mechanism; 120 - Roller clamping mechanism; 121 - Mounting plate; 122 - Bracket. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Reference Figures 1 to 5 This embodiment provides a rolling device for rolling the surface of a workpiece 90 to be rolled. The device includes a loading mechanism 10, a transmission mechanism 20, at least one floating rolling unit 30, a contact state detection unit 40, and a control mechanism 50.

[0029] The surface of workpiece 90 to be rolled is the inner surface of an annular part, which can be the inner raceway surface of the bearing inner ring or the inner surface of the sealing ring; the following description uses the inner raceway surface of the bearing inner ring as the main example.

[0030] The loading mechanism 10 includes a loading control unit 11 and a loading output unit 12. The loading control unit 11 receives the loading adjustment signal output by the control mechanism 50, and the loading output unit 12 outputs an adjustable load to the transmission mechanism 20. In this way, the loading mechanism 10 adjusts the output load of the loading output unit 12 according to the loading adjustment signal input to the loading control unit 11.

[0031] The transmission mechanism 20 is connected to the loading output unit 12 and is used to transmit the output load of the loading output unit 12 to the floating rolling unit 30.

[0032] The floating rolling unit 30 is movably connected to the transmission mechanism 20 and forms rolling contact with the surface of the workpiece 90 to be rolled during the rolling process. Specifically, the floating rolling unit 30 is movably connected to the transmission mechanism 20 along the loading direction in which it presses against the surface of the workpiece 90 to be rolled during the rolling process.

[0033] The contact state detection unit 40 is connected to at least one of the floating rolling unit 30 and the transmission mechanism 20. The contact state detection unit 40 is used to output a contact state signal, which characterizes the contact state between the floating rolling unit 30 and the surface of the workpiece 90 to be rolled.

[0034] The input end of the control mechanism 50 is connected to the contact state detection unit 40, and the output end is connected to the loading control unit 11. The control mechanism 50 determines the rolling load value according to the contact state signal, and outputs a loading adjustment signal to the loading control unit 11 according to the difference between the rolling load value and the target rolling load value.

[0035] It should be noted that the above-mentioned contact state signal can characterize at least one of the following: the relative displacement of the floating rolling unit 30 relative to the transmission mechanism 20, the deformation of the elastic support unit 60, or the force exerted on the floating rolling unit 30 during the rolling process.

[0036] In one embodiment, the loading mechanism 10 is a fluid pressure loading mechanism, the loading control unit 11 includes a pressure regulating element, such as a pressure regulating valve or a proportional valve, and the loading output unit 12 is a piston rod. The pressure regulating element adjusts the output load of the piston rod according to the loading adjustment signal output by the control mechanism 50.

[0037] In another embodiment, the loading mechanism 10 may also be an electric loading mechanism, the loading control unit 11 includes a servo drive unit, the loading output unit 12 includes a linear output rod, and the servo drive unit adjusts the output load of the linear output rod according to the loading adjustment signal.

[0038] With the structure of this embodiment, when the contact state between the floating rolling unit 30 and the workpiece 90 to be rolled changes, the contact state detection unit 40 can output a contact state signal reflecting the change, and the control mechanism 50 adjusts the output load of the loading mechanism 10 accordingly. Thus, the rolling device forms a feedback adjustment process of contact state detection, rolling load determination, load difference comparison, and output load adjustment, which helps to reduce the fluctuation of the actual rolling load caused by workpiece shape errors, dimensional fluctuations, clamping deviations, processing vibrations, or thermal deformation, and makes the pressure degree of different processing areas tend to be consistent.

[0039] It is important to emphasize that existing roller burnishing tools mostly employ preset loading forces for processing, with the burnishing load primarily determined by rigid displacement or the loading system's set value. In actual processing, the actual contact load between the floating roller burnishing unit 30 and the workpiece 90's surface to be burned may still fluctuate, leading to inconsistent pressure levels in localized areas. Existing structures typically lack real-time sensing of the actual contact state, making it difficult to promptly identify changes in the burnishing load and to proactively adjust loading parameters based on the processing status. Furthermore, the burnished parts often employ rigid support structures, which lack sufficient compensation capacity when encountering localized protrusions or dimensional changes, easily resulting in localized contact stress concentration. Therefore, this application, through the cooperation of the floating roller burnishing unit 30, contact state detection unit 40, control mechanism 50, transmission mechanism 20, and loading mechanism 10, enables the contact state signal to be used to determine the burnishing load value. The output load of the loading output unit 12 is adjusted based on the difference between this burnishing load value and the target burnishing load value, thereby reducing fluctuations in the actual burnishing load, making the pressure levels in different areas of the surface to be burned more consistent, and improving the stability and consistency of the burnishing processing quality.

[0040] In order to enable the floating rolling unit 30 to respond to the local shape changes of the workpiece 90 surface to be rolled and to form a contact state change that is easy to detect, this embodiment further provides an elastic support unit 60 on the basis of the above.

[0041] Reference Figures 3 to 5 The elastic support unit 60 is disposed between the floating rolling unit 30 and the transmission mechanism 20. When the floating rolling unit 30 moves relative to the transmission mechanism 20, the elastic support unit 60 undergoes elastic deformation.

[0042] In the illustrated embodiment, at least one floating rolling unit 30 is comprised of multiple floating rolling units 30, which are spaced apart around the transmission mechanism 20. Each floating rolling unit 30 is provided with an elastic support unit 60 between itself and the transmission mechanism 20.

[0043] Specifically, the floating rolling unit 30 includes a rolling seat 31 and a rolling element 32. The rolling seat 31 is movably connected to the transmission mechanism 20, and the rolling element 32 is rotatably disposed on the rolling seat 31, with at least a portion of the surface of the rolling element 32 exposed above the rolling seat 31 so as to roll into contact with the surface of the workpiece 90 to be rolled during processing. The elastic support unit 60 can be an elastic compression member, such as a compression spring; the elastic compression member is disposed between the rolling seat 31 and the transmission mechanism 20, and its extension and retraction direction is parallel to the movement direction of the rolling seat 31.

[0044] When the rolling element 32 passes through areas of local protrusions, roundness errors, or waviness in the raceway, multiple floating rolling units 30 can generate minute radial displacements through internal springs, thereby automatically compensating for workpiece geometric errors. Simultaneously, the contact state detection unit 40 can detect changes in the floating displacement of the rolling element 32 or the rolling seat 31 in real time and feed the detection results back to the control mechanism 50. The control mechanism 50 dynamically adjusts the loading adjustment signal based on the detection results, thereby adjusting the loading force to maintain a stable contact load between the rolling element 32 and the raceway, ultimately achieving stable control of the rolling contact stress field and plastic strain field.

[0045] In the illustrated embodiment, the rolling element 32 is a ball; in another embodiment, the rolling element 32 may also be a roller.

[0046] When the rolling element 32 passes through a locally raised area on the surface of the workpiece 90 to be rolled, the force on the rolling element 32 increases, and the rolling seat 31 retracts relative to the transmission mechanism 20. The elastic support unit 60 is compressed and absorbs part of the load change. When the rolling element 32 passes through a locally recessed area, the force on the rolling element 32 decreases, the elastic support unit 60 releases its elastic deformation energy and pushes the rolling seat 31 toward the surface to be rolled, so that the rolling element 32 remains in contact with the surface to be rolled. The retainer 80 can be provided at the end of the transmission mechanism 20 to limit the circumferential position of the multiple floating rolling units 30 and to provide guidance or installation space for the movement of the rolling seat 31.

[0047] With the structure of this embodiment, the floating rolling unit 30 is no longer fixed to the transmission mechanism 20 in a completely rigid manner, but can generate relative movement through the cooperation of the rolling seat 31 and the elastic support unit 60. This relative movement can, on the one hand, mitigate the sudden change in contact load caused by local shape error of the workpiece 90, and on the other hand, provide the contact state detection unit 40 with detectable displacement, deformation or force changes, thereby helping to improve the stability of the rolling contact process.

[0048] In other embodiments, the elastic support unit 60 may also be an elastic rubber ring. Of course, a return cylinder, an electromagnetic reset device, or a pneumatic reset device may also be used to replace the elastic support unit 60.

[0049] To enable the load output by the loading mechanism 10 to act on the hole-like or groove-like surface to be rolled, this embodiment further describes a force conversion structure of the transmission mechanism 20. (Refer to...) Figure 2 and Figure 3 The transmission mechanism 20 includes a conversion input section 21 and a conversion output section 22. The conversion input section 21 is connected to the loading output section 12, and the floating rolling unit 30 is connected to the conversion output section 22. The loading output section 12 and the conversion input section 21 are both movably arranged along a first direction, and the conversion output section 22 is movably arranged along a second direction, which intersects with the first direction.

[0050] It should be noted that the first direction and the second direction in this application are used to distinguish the movement directions of different components and do not limit the absolute spatial orientation of the rolling device in actual use. In the illustrated embodiment, the rolling device has a device axis, the first direction can be understood as the direction parallel to the device axis, and the second direction can be understood as the radial direction relative to the device axis.

[0051] The input conversion unit 21 has a first force transmission surface 211, and the output conversion unit 22 has a second force transmission surface 221 that contacts the first force transmission surface 211. Both the first force transmission surface 211 and the second force transmission surface 221 are inclined relative to the first direction. When the loading output unit 12 drives the input conversion unit 21 to move along the first direction, the first force transmission surface 211 pushes the second force transmission surface 221, causing the output conversion unit 22 to move along the second direction, thereby driving the floating rolling unit 30 to apply a load to the surface of the workpiece 90 to be rolled.

[0052] In the illustrated embodiment, the rolling device has a device axis, a first direction parallel to the device axis, and a second direction radially relative to the device axis. The input conversion unit 21 is a conical drive member, and the output conversion unit 22 is an annular expansion member (also called an elastic expansion sleeve). The first force transmission surface 211 is a first conical surface of the conical drive member, and the second force transmission surface 221 is a second conical surface of the annular expansion member. The conical drive member is connected to the loading output unit 12. The annular expansion member is made of spring steel and can be connected to the loading mechanism 10 or the main structure of the rolling device via a flange connector 70. When the loading output unit 12 pushes the conical drive member along the first direction, the first and second conical surfaces interact, causing the annular expansion member to expand radially. Multiple floating rolling units 30 move with the annular expansion member away from the device axis and press against the inner circumferential raceway surface of the bearing inner ring.

[0053] With the structure of this embodiment, the load output by the loading mechanism 10 along the first direction can be converted into a rolling load in the second direction through the inclined force transmission surface, so that the rolling device can extend into the interior of annular workpieces such as the inner ring of the bearing and apply radial rolling action to the inner circumferential raceway surface.

[0054] Understandably, the combination of the inclined plane transmission pair, the conical drive component, and the annular expansion component enables multiple floating rolling units 30 to be loaded synchronously by the same loading mechanism 10, which helps to simplify the loading structure and improve the consistency of the rolling action in the circumferential direction.

[0055] In another embodiment, the transmission mechanism 20 may include an axial push rod, a push ring, multiple connecting rods, and multiple radial sliders. The axial push rod is connected to the loading output unit 12, the push ring is fixed to the axial push rod, and the multiple connecting rods are spaced apart around the axis of the device. One end of each connecting rod is hinged to the push ring, and the other end is hinged to a radial slider. The radial slider is movably disposed in a guide groove of the transmission mechanism 20 relative to the axis of the device, and the floating rolling unit 30 is connected to the radial slider. When the loading output unit 12 pushes the axial push rod to move along the axis of the device, the push ring drives the multiple connecting rods to swing, and the connecting rods push the corresponding radial sliders to move radially, thereby driving the multiple floating rolling units 30 to press against the surface of the workpiece 90 to be rolled; when the loading output unit 12 moves in the opposite direction, the connecting rods drive the radial sliders to retract, or the radial sliders retract under the action of the reset elastic element.

[0056] With this structure, the axial load output by the loading mechanism 10 can be converted into a radial load through the push ring, connecting rod, and radial slider, and then transmitted to the floating rolling unit 30. When multiple connecting rods are arranged around the axis of the device, multiple floating rolling units 30 can also move radially synchronously, which is beneficial for circumferential rolling loading on the surface of ring-shaped or hole-shaped workpieces to be rolled.

[0057] To convert the changes in contact state during the rolling process into load information that the control mechanism 50 can process, this embodiment further explains the contact state detection unit 40 and the method for determining the rolling load value. (Refer to...) Figure 4 and Figure 5 The contact state detection unit 40 can be disposed between the rolling base 31 and the transmission mechanism 20, or between the rolling base 31 and the elastic support unit 60. The contact state signal can characterize at least one of the following: the relative displacement of the floating rolling unit 30 relative to the transmission mechanism 20, the deformation of the elastic support unit 60, or the force exerted on the floating rolling unit 30 during the rolling process.

[0058] In one embodiment, the contact state detection unit 40 is a displacement detection element that detects the displacement of the rolling seat 31 relative to the transmission mechanism 20; in another embodiment, the contact state detection unit 40 is a force detection element that is disposed on the force path of the floating rolling unit 30 and outputs a force signal.

[0059] When the contact status signal represents the displacement of the rolling seat 31 or the deformation of the elastic support unit 60, the control mechanism 50 can determine the rolling load value based on the equivalent stiffness of the elastic support unit 60.

[0060] For example, during the processing, the rolling element 32 comes into contact with the raceway, generating a contact load, and the rolling seat 31 floats in the radial direction under the load. The displacement detection device detects the displacement x(t) of the rolling seat 31 in real time. The equivalent stiffness of the elastic support unit 60 is k, and the elastic support force can be expressed as Fs=k·x(t).

[0061] Where: x(t) represents the floating displacement of the rolling element 32 or the rolling seat 31 at time t; t is the processing time.

[0062] It should be noted that the displacement signal can directly reflect the changes in the contact state between the rolling element 32 and the raceway. When there are roundness errors, waviness errors, or clamping eccentricities in the raceway, the displacement curve will exhibit periodic fluctuation characteristics. Therefore, the displacement of the rolling element 32 or the rolling bearing 31 can be used as an online characterization parameter for the rolling contact state.

[0063] Considering the influence of assembly state and structural deformation on load transfer, a structural correction factor λ can be introduced to obtain the first load value (also known as the rolling element equivalent displacement load) F. r1 =λ·k·x(t).

[0064] The structural correction coefficient λ can be obtained through calibration tests. If the contact state detection unit 40 directly outputs the force signal, the control mechanism 50 can determine the rolling load value based on the force signal, or use the force signal and displacement signal together for load evaluation.

[0065] By adopting the above configuration, the floating displacement of the rolling element 32 or the rolling bearing 31 is converted into the actual load online.

[0066] The control mechanism 50 presets the target rolling load value F0 and determines the rolling load value Fc in real time. The error between the two is: e(t) = F0 - Fc C Where e(t) is the real-time load error. The error value is used to characterize the degree of deviation between the current rolling state and the target strengthening state. When Fc is higher than F0, the control mechanism 50 outputs a load adjustment signal to the load control unit 11 to reduce the output load of the load output unit 12; when Fc is lower than F0, the control mechanism 50 outputs a load adjustment signal to the load control unit 11 to increase the output load of the load output unit 12. The control mechanism 50 can use proportional regulation, PID regulation, or other feedback regulation methods to achieve this process.

[0067] With the structure of this embodiment, the rolling device does not determine the rolling state solely based on the set output value of the loading mechanism 10, but rather obtains the actual contact state through the displacement, deformation, or force information at the floating rolling unit 30. Since this contact state directly originates from the interaction between the floating rolling unit 30 and the workpiece 90 surface to be rolled, it can more accurately reflect the load changes in the local processing area, which is beneficial for improving the timeliness and targeting of rolling load adjustment.

[0068] To balance the actual contact state at the floating rolling unit 30 and the output state of the loading mechanism 10, this embodiment further includes a loading state detection unit based on any of the aforementioned embodiments. The loading state detection unit is connected to the loading mechanism 10 and outputs a loading state signal. The control mechanism 50 determines a first load value based on the contact state signal, a second load value based on the loading state signal, and a rolling load value based on the first and second load values.

[0069] In embodiments where the loading mechanism 10 is a fluid pressure loading mechanism, the loading state detection unit can be a pressure detection element, which is installed in the fluid pressure circuit or the pressure chamber of the loading mechanism 10 to detect the real-time pressure P(t). When the loading output unit 12 is a piston rod, the output force of the loading mechanism 10 can be expressed as F. h =P·A, where A is the effective pressure-bearing area of ​​the loading mechanism 10.

[0070] In the embodiment where the transmission mechanism 20 employs a conical drive member and an annular expansion member, a mapping relationship can be established between the hydraulic pressure and the radial loading force of the floating rolling unit 30, for example, the second load value F. r2 =η·P·A·tan(α), where η is the transmission efficiency and α is the half-cone angle of the conical drive component.

[0071] Simultaneously acquiring displacement feedback and hydraulic pressure feedback, the control system performs fusion calculations on the two signals. Displacement feedback: F r1 =λ·k·x(t;Hydraulic pressure feedback:F r2 =η·P·A·tan(α). The control mechanism 50 can be configured according to Fc=w1·F r1 +w2·F r2 Determine the comprehensive rolling load value Fc, where w1 and w2 are weighting coefficients, which can be determined based on calibration tests.

[0072] With the structure of this embodiment, the control mechanism 50 can obtain the local contact state at the floating rolling unit 30 using the contact state detection unit 40, and the overall output state of the loading mechanism 10 using the loading state detection unit. The combination of the two types of signals helps to reduce the judgment deviation caused by the influence of local interference or transmission error on a single detection signal, and improves the stability of the rolling load evaluation.

[0073] To reduce the hysteresis effect in the feedback adjustment process, this embodiment further includes a position acquisition unit and a storage unit based on any of the aforementioned embodiments. The position acquisition unit outputs a position signal, which represents the processing position of the floating rolling unit 30 on the surface of the workpiece 90 to be rolled. The position acquisition unit can be an angle encoder related to the rotational motion of the workpiece 90, or a coordinate acquisition module that reads the feed coordinates of the CNC machine tool 100. The control mechanism 50 associates the contact state signal, the rolling load value, and the position signal to generate position load data, and stores the position load data in the storage unit.

[0074] During the rolling process, when the position signal output by the position acquisition unit indicates that the current processing position is close to the processing position recorded in the position load data, and the position difference between the two reaches a preset lead time, the control mechanism 50 corrects the load adjustment signal according to the position load data. For example, if the rolling load increases at a certain circumferential position in the previous processing cycle, the control mechanism 50 can correct the load adjustment signal in the next processing cycle according to the position load data corresponding to that position, before the floating rolling unit 30 reaches that position, so that the loading mechanism 10 reduces or adjusts the output load in advance.

[0075] With the structure of this embodiment, the rolling device can not only provide feedback adjustment after changes in contact state, but also pre-correct the subsequent processing position based on the recorded position load data. This position-related control method helps reduce the impact of control lag on load stability, and is especially suitable for workpiece surfaces with periodic processing trajectories, such as the inner ring raceway surface of bearings.

[0076] To mitigate potential load differences among the multiple floating rolling units 30, this embodiment further incorporates multiple unit adjustment components in addition to the existing multiple floating rolling units 30. Each unit adjustment component is connected to one of the multiple floating rolling units 30, and each unit adjustment component has a movable adjustment output section connected to its connected floating rolling unit 30 or elastic support unit 60. The unit adjustment component can be a piezoelectric actuator or a miniature linear actuator. The control mechanism 50 determines multiple unit load values ​​based on the contact state signals of the multiple floating rolling units 30, and generates multiple unit adjustment signals based on the differences between the multiple unit load values. The multiple unit adjustment components adjust the preload of the multiple floating rolling units 30 according to the multiple unit adjustment signals.

[0077] For example, when multiple floating rolling units 30 are spaced apart around the axis of the device, the control mechanism 50 can acquire the contact state signal corresponding to each floating rolling unit 30 and calculate the unit load value of each floating rolling unit 30. If the unit load value of one floating rolling unit 30 is higher than the average of multiple unit load values, the control mechanism 50 can control the unit adjusting component corresponding to that floating rolling unit 30 to reduce its preload; if the unit load value of another floating rolling unit 30 is lower than the average of multiple unit load values, the control mechanism 50 can control the corresponding unit adjusting component to increase its preload.

[0078] With the structure of this embodiment, the rolling device can further balance the unit-level load on the basis of overall load adjustment. By adjusting the preload of each of the multiple floating rolling units 30, it is beneficial to reduce the force difference between multiple rolling contact points in the circumferential direction, thereby improving the consistency of the circumferential processing quality of the surface to be rolled.

[0079] This application also provides a surface strengthening device. (Refer to...) Figure 6 and Figure 7 The surface strengthening equipment includes a CNC machine tool 100 and the rolling device in any of the foregoing embodiments. The CNC machine tool 100 includes a workpiece clamping mechanism 110 for mounting the workpiece 90 and a rolling clamping mechanism 120 for mounting the rolling device. The rolling clamping mechanism 120 may include a mounting plate 121 and a bracket 122 (also called a tool holder), and the rolling device is mounted on the bracket 122 via the mounting plate 121. The workpiece clamping mechanism 110 may be a chuck for clamping annular workpieces such as bearing inner rings.

[0080] During processing, the workpiece 90 is first mounted on the workpiece clamping mechanism 110, and the rolling device is mounted on the rolling clamping mechanism 120. Then, the position between the rolling device and the workpiece 90 is adjusted via the feed system of the CNC machine tool 100, ensuring that the axis of the rolling device and the axis of the bearing inner ring meet the processing requirements, and the starting position for processing is determined. After the control mechanism 50 sets the target rolling load value F0, the loading mechanism 10 drives the loading output unit 12 to output the load according to the initial loading adjustment signal. The transmission mechanism 20 transmits this load to the floating rolling unit 30, causing the rolling element 32 to press against the surface of the workpiece 90 to be rolled. The workpiece 90 rotates under the drive of the workpiece clamping mechanism 110, and the rolling device moves along the processing trajectory with the feed components of the CNC machine tool 100, causing the rolling element 32 to form continuous rolling contact on the surface to be rolled. During the rolling process, the contact state detection unit 40 continuously outputs a contact state signal. The control mechanism 50 determines the rolling load value based on the contact state signal and corrects the loading adjustment signal in real time based on the difference between the rolling load value and the target rolling load value F0, so that the loading mechanism 10 adjusts the output load.

[0081] Through the above process, the surface of the workpiece 90 to be rolled is subjected to continuous rolling extrusion, and the surface material undergoes plastic deformation, which is conducive to the formation of a surface reinforcement layer. In the case of machining the inner ring raceway surface of a bearing, this process is beneficial to improving the consistency of the raceway surface structure and the pressure state.

[0082] For ease of understanding, the following example of machining the inner circumference raceway surface of the bearing inner ring illustrates a parameter calculation process. This parameter is only used to explain the control process and is not intended to limit the scope of protection of this application.

[0083] The bearing inner diameter of workpiece 90 is 60mm, the total loading force of the rolling device is set to 350kgf, and there are 6 floating rolling units 30. The target rolling load corresponding to each floating rolling unit 30 is approximately 350×9.8÷6≈572N.

[0084] If the floating compensation displacement range of the elastic support unit 60 is 0.5mm to 1.5mm, the equivalent stiffness k of the elastic support unit 60 is 700N / mm, and the structural correction factor λ is 1, according to F r1 =λ·k·x(t), when the target rolling load is 572N, substituting it, we can get: 572N=1·700N / mm·x(t), corresponding to a target displacement x(t) of approximately 0.82mm.

[0085] In the embodiment where the transmission mechanism 20 uses a conical drive component and an annular expansion component, if the half-cone angle α of the conical drive component is 15°, the transmission efficiency η is 0.9, the hydraulic cylinder diameter d of the loading mechanism 10 is 20mm, and the effective pressure area A is approximately 314mm², according to F... r2=η·P·A·tan(α), substituting, we get: 572N=0.9·P·314mm 2 ·tan(15°), corresponding to a target pressure P of approximately 7.6 MPa.

[0086] Under normal operating conditions, the load F of a single floating rolling unit 30 of this device is... r1 =572N, spring displacement x(t)=0.82mm, hydraulic pressure P=7.6MPa.

[0087] During the rolling process, if the rolling element 32 passes through a local protruding area on the surface of the workpiece 90 to be rolled, and the contact state detection unit 40 detects a displacement x(t) of 1 mm, then according to F... r1 The current load value F can be obtained by calculating λ·k·x(t). r1 The current load is approximately 700N. The target rolling load is 572N. Since the current load is higher than the target rolling load, the control mechanism 50 outputs a load adjustment signal based on the difference, causing the pressure regulator to reduce the hydraulic pressure, for example, adjusting it from 7.6MPa to approximately 6.2MPa. After the hydraulic pressure decreases, the load output unit 12 drives the conical drive to retract, reducing the radial expansion of the conversion output unit 22. This reduces the loading force on the rolling element 32, and the displacement detected by the contact state detection unit 40 gradually returns to approximately 0.82mm, corresponding to a rolling load value approaching the target rolling load value.

[0088] When using the surface strengthening equipment of this embodiment, the CNC machine tool 100 provides workpiece clamping, device installation, and processing feed conditions, while the rolling device provides a detectable and adjustable rolling load. When the two work together, the load output can be corrected according to the actual contact state during continuous rolling processing, which helps reduce load fluctuations caused by workpiece errors and processing disturbances, and improves the stability and repeatability of the rolling processing quality.

[0089] In summary, when the surface of the workpiece 90 to be rolled is the raceway surface of the bearing inner ring, the rolling element 32 is pressed against the surface to be rolled under the action of the loading mechanism 10 and the transmission mechanism 20, forming rolling contact. The rolling seat 31 is movably connected to the transmission mechanism 20, and the elastic support unit 60 is disposed between the rolling seat 31 and the transmission mechanism 20. When the rolling element 32 passes through a local protrusion, a roundness error area, or a clamping deviation area, the rolling seat 31 is displaced relative to the transmission mechanism 20, and the elastic support unit 60 undergoes elastic deformation, thereby mitigating sudden changes in local load and maintaining the contact state between the rolling element 32 and the surface to be rolled. The contact state detection unit 40 detects the relative displacement of the floating rolling unit 30, the deformation of the elastic support unit 60, or the rolling force, and outputs a contact state signal to the control mechanism 50. The control mechanism 50 determines the rolling load value based on the contact state signal, and outputs a loading adjustment signal to the loading control unit 11 based on the difference between the rolling load value and the target rolling load value, so that the output load of the loading output unit 12 is corrected by the transmission mechanism 20.

[0090] Therefore, the rolling device provided in this application can adjust the actual contact load during the processing, reduce load fluctuations caused by workpiece errors, vibration or thermal deformation, make the pressure on the surface to be rolled more uniform, which is conducive to forming a more stable plastic deformation layer and improving the surface strengthening effect, surface hardness and the uniformity of residual compressive stress distribution.

[0091] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0092] The rolling apparatus and surface strengthening equipment provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the solution and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of this application.

Claims

1. A rolling device for rolling the surface of a workpiece (90) to be rolled, characterized in that, include: The loading mechanism (10) includes a loading control unit (11) and a loading output unit (12). The loading mechanism (10) adjusts the output load of the loading output unit (12) according to the loading adjustment signal input to the loading control unit (11). The transmission mechanism (20) is connected to the loading output unit (12) in a transmission manner; At least one floating rolling unit (30) is movably connected to the transmission mechanism (20) for rolling contact with the surface of the workpiece (90) to be rolled during rolling. A contact state detection unit (40) is connected to at least one of the floating rolling unit (30) and the transmission mechanism (20) for outputting a contact state signal, the contact state signal representing the contact state between the floating rolling unit (30) and the surface of the workpiece (90) to be rolled; The control mechanism (50) has its input end connected to the contact state detection unit (40) and its output end connected to the loading control unit (11). It is used to determine the rolling load value according to the contact state signal and output the loading adjustment signal to the loading control unit (11) according to the difference between the rolling load value and the target rolling load value.

2. The rolling device as described in claim 1, characterized in that, It also includes an elastic support unit (60), which is disposed between the floating rolling unit (30) and the transmission mechanism (20). The elastic support unit (60) is used to elastically deform when the floating rolling unit (30) moves relative to the transmission mechanism (20).

3. The rolling device as described in claim 2, characterized in that, The at least one floating rolling unit (30) is a plurality of floating rolling units (30), the plurality of floating rolling units (30) are arranged at intervals around the transmission mechanism (20), and each floating rolling unit (30) is provided with an elastic support unit (60) between it and the transmission mechanism (20). The floating rolling unit (30) includes a rolling seat (31) and a rolling element (32). The rolling seat (31) is movably connected to the transmission mechanism (20), and the rolling element (32) is rotatably disposed on the rolling seat (31). The elastic support unit (60) is an elastic compression member, which is disposed between the rolling seat (31) and the transmission mechanism (20), and the extension and retraction direction of the elastic compression member is parallel to the movement direction of the rolling seat (31).

4. The rolling device as described in claim 2, characterized in that, The contact state signal represents at least one of the relative displacement of the floating rolling unit (30) relative to the transmission mechanism (20), the deformation of the elastic support unit (60), or the force exerted on the floating rolling unit (30) during rolling.

5. The rolling device as described in claim 1, characterized in that, The transmission mechanism (20) includes a conversion input section (21) and a conversion output section (22). The conversion input section (21) is connected to the loading output section (12), and the floating rolling unit (30) is connected to the conversion output section (22). The loading output section (12) and the conversion input section (21) are both movably arranged along a first direction, and the conversion output section (22) is movably arranged along a second direction, which intersects with the first direction. The conversion input section (21) has a first force transmission surface (211), and the conversion output section (22) has a second force transmission surface (221) that contacts the first force transmission surface (211). Both the first force transmission surface (211) and the second force transmission surface (221) are inclined relative to the first direction.

6. The rolling device as described in claim 5, characterized in that, The rolling device has a device axis, the first direction is parallel to the device axis, and the second direction is radial relative to the device axis; the conversion input part (21) is a conical drive member, the conversion output part (22) is an annular expansion member, the first force transmission surface (211) is a first conical surface disposed on the conical drive member, and the second force transmission surface (221) is a second conical surface disposed on the annular expansion member.

7. The rolling device according to any one of claims 1-6, characterized in that, It also includes a loading state detection unit, which is connected to the loading mechanism (10) and outputs a loading state signal. The control mechanism (50) determines a first load value based on the contact state signal, determines a second load value based on the loading state signal, and determines the rolling load value based on the first load value and the second load value.

8. The rolling device according to any one of claims 1-6, characterized in that, It also includes a position acquisition unit and a storage unit. The position acquisition unit outputs a position signal, which represents the processing position of the floating rolling unit (30) on the surface to be rolled on the workpiece (90). The control mechanism (50) associates the contact state signal, the rolling load value and the position signal to generate position load data and stores it in the storage unit. When the position difference between the current processing position represented by the position signal and the processing position recorded in the position load data reaches a preset advance amount, the control mechanism (50) corrects the loading adjustment signal according to the position load data.

9. The rolling device according to any one of claims 1-6, characterized in that, The loading mechanism (10) is a fluid pressure loading mechanism, the loading output part (12) is a piston rod, and the loading control part (11) includes a pressure regulating component. The pressure regulating component is connected to the output end of the control mechanism (50), and the control mechanism (50) adjusts the output load of the piston rod through the pressure regulating component.

10. A surface strengthening device, characterized in that, The device includes a CNC machine tool (100) and a rolling device as described in any one of claims 1-9, wherein the CNC machine tool (100) includes a workpiece clamping mechanism (110) for mounting a workpiece (90) and a rolling clamping mechanism (120) for mounting the rolling device.

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