A multi-axis composite machining tool

Abstract

This invention relates to the field of multi-axis combined machining center technology, and more particularly to a multi-axis composite machining center. The invention comprises a frame, a moving assembly, a workpiece cradle, a stress detection unit, and a process control unit. The moving assembly includes an X-axis moving mechanism, a Y-axis moving mechanism, and a Z-axis moving mechanism. The Z-axis moving mechanism includes a milling cutter machining unit and a grinding head machining unit. The workpiece to be processed is carried by the workpiece cradle, enabling coordinated operation of different machining process units such as the milling cutter machining unit and the grinding head machining unit, thereby accelerating machining efficiency. The process control unit determines the stress unit vector and adjusts the single sliding distance of the feed slide according to the changes in the stress unit vector in the spatial and temporal dimensions. This allows for adaptive adjustment of machining parameters for specific machining time periods based on real-time analysis of machining process parameters, improving the machining effect and accuracy of thin-walled workpieces.

Description

Technical Field

[0001] This invention relates to the field of multi-axis combined machining center technology, and more particularly to a multi-axis composite machining center. Background Technology

[0002] Multi-axis composite machining tools are increasingly widely used in the field of mechanical processing. Multi-axis composite machining tools can integrate multiple processing technologies on the same machine, effectively improving processing efficiency and processing accuracy. In milling and grinding processes, the interaction forces between the workpiece and the cutting tool or grinding wheel are complex and variable, which can easily lead to the difficulty in achieving ideal processing accuracy.

[0003] Thin-walled parts are increasingly used in the diverse needs of modern industrial production. However, due to their poor rigidity, the machining of thin-walled parts is more susceptible to errors caused by cutting forces and machining impacts. Different machining processes have different requirements for machining parameters, making it difficult to avoid machining damage and deformation of thin-walled parts in actual machining. This affects machining efficiency and product quality. Therefore, there is an urgent need for machine tools that can adapt to the process of multi-axis operation to meet the needs of modern industrial production.

[0004] For example, Chinese Patent Publication No. CN110814758A discloses a variable-steering multi-spindle drilling and milling machine tool. Its technical solution is as follows: the control drive system controls and drives the main motor, speed regulating motor, and lifting motor to start, stop, and change speed according to the input instructions through the data drive line, as well as the opening and closing of the electromagnetic brake, the inward and outward movement of the transverse feed table, the left and right movement of the longitudinal feed table, and the up and down movement of the machine tool lifting table. It can realize efficient milling of workpieces and simultaneous drilling of hole groups formed by multiple holes, which greatly improves the processing efficiency of milling and drilling.

[0005] The following problems still exist in the existing technology:

[0006] Existing technologies do not consider that excessively large or small feed rates of the grinding head during the machining of thin-walled workpieces can easily cause axial movement and radial runout of the workpiece, affecting machining accuracy. Existing technologies cannot make adaptive adjustments to machining parameters based on real-time analysis of machining process parameters, nor can they adjust machining parameters for special machining time periods, thus affecting the machining effect and accuracy of thin-walled workpieces. Summary of the Invention

[0007] Therefore, the present invention provides a multi-axis composite machining tool to overcome the problems in the prior art that it cannot adapt to the processing parameters based on real-time analysis of the processing parameters and cannot make adaptive adjustments to the processing parameters for special processing time periods.

[0008] To achieve the above objectives, the present invention provides a multi-axis composite machining center, comprising:

[0009] A frame, including a base and a crossbeam disposed on the base;

[0010] The moving component includes an X-axis moving mechanism, a Y-axis moving mechanism and a Z-axis moving mechanism. The X-axis moving mechanism includes a slide rail disposed at the front of the crossbeam and an X-axis slide saddle disposed on the slide rail.

[0011] The Y-axis moving mechanism includes a slide rail disposed on the upper surface of the base and a Y-axis slide saddle disposed on the slide rail;

[0012] The Z-axis moving mechanism includes a first Z-axis slide saddle and a second Z-axis slide saddle respectively disposed on slide rails on the surface of the X-axis slide saddle. A milling cutter processing unit is disposed on the first Z-axis slide saddle, and a grinding head processing unit is disposed on the second Z-axis slide saddle. The grinding head processing unit includes a grinding head and a feed slide that drives the grinding head to slide along the radial direction of the grinding head's rotation.

[0013] A workpiece cradle, used to carry the workpiece to be processed, includes a support frame fixed on the Y-axis slide saddle and a cradle body. The two ends of the cradle body are connected to the support frame through a rotating shaft and bearings, so that the cradle body rotates about the axis of the rotating shaft.

[0014] Stress detection units are respectively installed at both ends of the support frame to obtain the contact stress value between the bearing and the bushing;

[0015] The process control unit is connected to the stress detection unit and the moving component, respectively, to determine the stress unit vector according to the contact stress at both ends of the support frame, and to adjust the single sliding distance of the feed slide according to the changes of the stress unit vector in the spatial and temporal dimensions.

[0016] Furthermore, a tool magazine for storing milling cutters is also provided on the side of the crossbeam near the milling cutter processing unit.

[0017] Furthermore, the grinding head processing unit also includes a grinding head revolution axis and a grinding head rotation axis. The grinding head revolution axis drives the grinding head on the feed slide to revolve around the axis of the grinding head revolution axis.

[0018] The grinding head rotation axis is set on the feed slide to drive the grinding head to rotate around the axis of rotation of the grinding head as a reference;

[0019] The circumference of the revolution is determined by the sliding distance of the grinding head along the radial direction of the grinding head's rotation, driven by the feed slide.

[0020] Furthermore, the cradle body is also provided with a workpiece spindle for carrying the workpiece to be processed, so that the workpiece spindle drives the workpiece to be processed to rotate.

[0021] Furthermore, the process control unit is used to determine the stress unit vector based on the contact stress value between the shaft and the bearing;

[0022] Wherein, the endpoint of the stress unit vector is the location of the maximum contact stress at the contact position between the shaft and the bearing, and the starting position of the stress unit vector is the center of the bearing.

[0023] Furthermore, the process control unit is used to determine the change of the stress unit vector over time, wherein,

[0024] The process control unit is used to obtain the stress unit vector corresponding to a certain number of times within a preset monitoring period, and to determine the maximum angle between two stress unit vectors based on the stress unit vectors corresponding to the certain number of times.

[0025] Furthermore, the process control unit is also used to determine whether the preset monitoring cycle is a processing feature cycle, wherein,

[0026] If the maximum included angle meets the characteristic phenomenon screening conditions, the process control unit determines that the preset monitoring period is the processing characteristic period;

[0027] The characteristic phenomenon screening condition is that the maximum included angle between two stress unit vectors at any end of the support frame exceeds a preset included angle threshold within a preset monitoring period.

[0028] Furthermore, the process control unit is also used to determine the characteristic angle of the stress unit vector in the spatial dimension, wherein,

[0029] Under the condition that the preset monitoring period is the processing characteristic period, the process control unit obtains the stress unit vectors corresponding to each end of the support frame at several times within the preset monitoring period, and determines the included angle between the two stress unit vectors at both ends of the support frame at the same time as the characteristic characterization angle.

[0030] Furthermore, the process control unit is also used to determine whether to adjust the single sliding distance of the feed slide, wherein,

[0031] The process control unit calculates the standard deviation of the included angle based on the characteristic included angle at several times. If the standard deviation of the included angle exceeds the preset reference value of the standard deviation of the included angle, the process control unit determines to adjust the single sliding distance of the feed slide.

[0032] Furthermore, the process control unit is used to adjust the single sliding distance of the feed slide, wherein,

[0033] The process control unit pre-acquires the target machining trajectory of the workpiece to be processed by the grinding head processing unit within the processing characteristic cycle, and determines the single sliding distance corresponding to the target machining trajectory at several times, and adjusts the single sliding distance based on the included angle standard deviation;

[0034] The single sliding distance is negatively correlated with the standard deviation of the included angle.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention sets up a frame, a moving component, a workpiece cradle, a stress detection unit, and a process control unit. The moving component includes an X-axis moving mechanism, a Y-axis moving mechanism, and a Z-axis moving mechanism. The Z-axis moving mechanism includes a milling cutter processing unit and a grinding head processing unit. The workpiece to be processed is carried by the workpiece cradle, realizing the coordinated cooperation of different processing unit axes such as the milling cutter processing unit and the grinding head processing unit, thereby accelerating the processing efficiency. The process control unit determines the stress unit vector according to the contact stress at both ends of the support frame of the workpiece cradle and adjusts the single sliding distance of the feed slide according to the changes of the stress unit vector in the spatial and temporal dimensions. This realizes the adaptive adjustment of processing parameters for special processing time periods based on the real-time analysis results of processing process parameters, thereby improving the processing effect and processing accuracy of thin-walled workpieces.

[0036] Furthermore, this invention constructs a three-dimensional machining space through the coordinated operation of X, Y, and Z axis moving mechanisms. The X-axis moving mechanism enables the X-axis slide saddle to move along the slide rail at the front of the crossbeam, the Y-axis moving mechanism enables the Y-axis slide saddle to move along the slide rail on the upper surface of the base, and the Z-axis moving mechanism, through the first Z-axis slide saddle and the second Z-axis slide saddle, respectively carries the milling cutter machining unit and the grinding head machining unit to move along the slide rail on the surface of the X-axis slide saddle. This multi-axis linkage provides rich motion trajectories for the machining tools, enabling the machine tool to process workpieces with complex shapes and meet diverse machining needs.

[0037] Furthermore, this invention achieves the rotation of the grinding head and its adjustable circumferential revolution through the grinding head's revolution axis, feed slide, and grinding head rotation axis within the grinding head processing unit. It is understood that when processing thin-walled workpieces, excessive grinding force may cause deformation or warping of the thin-walled portion. By precisely controlling the radial feed of the grinding head, fine grinding depth adjustment can be achieved, avoiding irreversible deformation of the thin-walled workpiece due to excessive grinding force. The circumferential radius of revolution is determined based on the sliding distance of the feed slide, allowing the grinding head to flexibly adjust its revolution radius when processing thin-walled workpieces. This avoids significant impact on the thin-walled workpiece due to sudden changes in processing parameters, ensuring the stability of the processing process.

[0038] Furthermore, this invention represents the real-time contact stress between the shaft and the bearing in vector form. It can be understood that during the processing, the stress state will continuously change as the processing progresses. The stress unit vector can capture these changes in real time, intuitively showing the distribution characteristics of the contact stress in the contact area. In different processing stages, the change of the stress unit vector can reflect the change of stress distribution. Thus, in the long and complex processing process, real-time analysis of the processing parameters is realized.

[0039] Furthermore, this invention selects processing characteristic cycles during the processing of thin-walled parts. It is understood that thin-walled workpieces are highly susceptible to deformation due to stress. By determining the processing characteristic cycle, the change of the stress unit vector in the time dimension can be monitored in real time, thereby understanding the stress state change trend of the thin-walled part at different times. When the maximum included angle exceeds the included angle threshold, it indicates that the part may have a large risk of deformation within that processing characteristic cycle, which facilitates timely adjustment of processing parameters and reduces part deformation. Thus, it enables adaptive adjustment of processing parameters for special processing time periods based on the real-time analysis results of processing process parameters, thereby improving the processing effect and accuracy of thin-walled workpieces.

[0040] Furthermore, this invention determines whether to adjust the single sliding distance of the feed slide by determining the characteristic angle of the stress unit vector in the spatial dimension. It can be understood that during the processing of thin-walled parts, the stress distribution at both ends of the support frame may be uneven. By determining the characteristic angle and the standard deviation of the angle, this difference in stress distribution can be reflected. When the standard deviation of the angle exceeds the reference value, it indicates that the stress distribution difference is large. Adjusting the single sliding distance of the feed slide can make the grinding head's processing force on the part more reasonable, avoid the influence of uneven stress, and reduce the deformation of the part caused by uneven stress. Thus, it realizes the adaptive adjustment of processing parameters for special processing time periods based on the real-time analysis results of processing process parameters, thereby improving the processing effect and processing accuracy of thin-walled workpieces. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the structure of a multi-axis composite machining center according to an embodiment of the present invention;

[0042] Figure 2 This is a schematic diagram of the structure of the grinding head processing unit according to an embodiment of the present invention;

[0043] Figure 3 This is a schematic diagram of the milling cutter machining unit according to an embodiment of the present invention;

[0044] Figure 4 This is a schematic diagram of the workpiece cradle according to an embodiment of the present invention;

[0045] Figure 5A flowchart illustrating the logic of the process control unit in this embodiment of the invention determining whether a preset monitoring period is a processing feature period.

[0046] In the diagram, 1-base, 2-crossbeam, 3-X-axis slide saddle, 31-X-axis first slide rail, 32-X-axis second slide rail, 33-X-axis third slide rail, 34-drive motor, 4-Y-axis slide saddle, 5-Z-axis first slide saddle, 51-turntable, 52-tool spindle, 6-Z-axis second slide saddle, 61-grinding head, 62-feed slide, 63-grinding head revolution axis, 64-grinding head rotation axis, 7-support frame, 8-cradle body, 9-tool changer magazine, 10-workpiece spindle. Detailed Implementation

[0047] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0048] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0049] It should be noted that in the description of this invention, the terms "upper," "lower," "inner," "outer," etc., which indicate the direction or positional relationship, are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0050] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0051] Please see Figures 1 to 4 As shown, Figure 1 This is a schematic diagram of the structure of a multi-axis composite machining center according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of the grinding head processing unit according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the milling cutter machining unit according to an embodiment of the present invention. Figure 4 This is a schematic diagram of the workpiece cradle according to an embodiment of the present invention;

[0052] The multi-axis composite machining center of this embodiment includes:

[0053] The frame includes a base 1 and a crossbeam 2 disposed on the base 1;

[0054] The moving component includes an X-axis moving mechanism, a Y-axis moving mechanism and a Z-axis moving mechanism. The X-axis moving mechanism includes a slide rail disposed at the front of the crossbeam 2 and an X-axis slide saddle 3 disposed on the slide rail.

[0055] The Y-axis moving mechanism includes a slide rail disposed on the upper surface of the base 1 and a Y-axis slide saddle 4 disposed on the slide rail;

[0056] The Z-axis moving mechanism includes a first Z-axis slide saddle 5 and a second Z-axis slide saddle 6 respectively disposed on slide rails on the surface of the X-axis slide saddle 3. A milling cutter processing unit is disposed on the first Z-axis slide saddle 5, and a grinding head processing unit is disposed on the second Z-axis slide saddle 6. The grinding head processing unit includes a grinding head 61 and a feed slide 62 that drives the grinding head 61 to slide along the radial direction of the grinding head's rotation.

[0057] The milling cutter machining unit includes a rotary table 51 and a tool spindle 52 mounted on the end face of the rotary table 51.

[0058] The workpiece cradle, which is used to carry the workpiece to be processed, includes a support frame 7 fixed on the Y-direction slide saddle 4 and a cradle body 8. The two ends of the cradle body 8 are connected to the support frame 7 through a rotating shaft and bearings, so that the cradle body 8 can rotate about the axis of the rotating shaft.

[0059] Specifically, the front of the crossbeam 2 is equipped with three X-axis slide rails in the same plane. The mounting plane of the X-axis slide rails is perpendicular to the mounting surface of the bottom of the crossbeam 2. The three X-axis slide rails are, from bottom to top, the first X-axis slide rail 31, the second X-axis slide rail 32, and the third X-axis slide rail 33. A lead screw and a drive motor 34 that drives the lead screw to rotate are provided between the first X-axis slide rail 31 and the second X-axis slide rail 32, so that the X-axis slide saddle 3 can slide along the first X-axis slide rail 31, the second X-axis slide rail 32, and the third X-axis slide rail 33 through the drive motor 34.

[0060] Stress detection units are respectively installed at both ends of the support frame 7 to obtain the contact stress value between the bearing and the bushing;

[0061] The process control unit is connected to the stress detection unit and the moving component respectively, and is used to determine the stress unit vector according to the contact stress at both ends of the support frame 7 and to adjust the single sliding distance of the feed slide 62 according to the changes of the stress unit vector in the spatial and temporal dimensions.

[0062] In implementation, the single sliding distance of the feed slide 62 refers to the linear distance that the feed slide 62 moves each time it slides along the radial direction of the grinding head's rotation during the machining process. It can be understood that workpiece machining includes rough grinding and fine grinding. The circumference of the grinding head 61's revolution can be adjusted according to the machining requirements to ensure a uniform distribution of grinding force. In the rough grinding stage, a larger single sliding distance can be set to improve the material removal rate; in the fine grinding stage, a smaller single sliding distance is set to ensure surface quality. The single sliding distance of the feed slide 62 in different machining time periods during rough grinding and fine grinding is pre-programmed and set according to the machining requirements of rough grinding and fine grinding. This is existing technology and will not be elaborated here.

[0063] Specifically, the stress detection unit can be a strain gauge stress sensor. During use, the strain gauge on the strain gauge stress sensor deforms, causing a change in the resistance value of the strain gauge. The corresponding stress value is calculated by measuring the change in resistance value. This is existing technology and will not be elaborated here.

[0064] Specifically, the present invention does not limit the specific structure of the process control unit, which can be constructed using logic components. The logic components can be field-programmable logic components, microprocessors, processors used in computers, etc., which will not be elaborated here.

[0065] Specifically, this invention constructs a three-dimensional machining space through the coordinated operation of X, Y, and Z axis moving mechanisms. The X-axis moving mechanism enables the X-axis slide saddle 3 to move along the slide rail at the front of the crossbeam 2, the Y-axis moving mechanism enables the Y-axis slide saddle 4 to move along the slide rail on the upper surface of the base 1, and the Z-axis moving mechanism, through the Z-axis first slide saddle 5 and Z-axis second slide saddle 6, respectively carries the milling cutter machining unit and the grinding head machining unit to move along the slide rail on the surface of the X-axis slide saddle 3. This multi-axis linkage provides rich motion trajectories for the machining tools, enabling the machine tool to process workpieces with complex shapes and meet diverse machining needs.

[0066] Specifically, a tool magazine 9 for storing milling cutters is also provided on the side of the crossbeam 2 near the milling cutter processing unit.

[0067] In practice, the tool changer 9 can adopt a disc design to store multiple tools. The robotic arm takes the tools out of the tool magazine and automatically installs them into the milling cutter machining unit. The computer controls the intelligent selection of the required machining tools, which is an existing technology and will not be elaborated here.

[0068] Please continue reading. Figure 3As shown, it is a structural schematic diagram of the milling cutter processing unit of an embodiment of the present invention. The grinding head processing unit also includes a grinding head revolution axis 63 and a grinding head rotation axis 64. The grinding head revolution axis 63 drives the grinding head 61 on the feed slide 62 to revolve around the axis of the grinding head revolution axis 63.

[0069] The grinding head rotation axis 64 is mounted on the feed slide 62 to drive the grinding head 61 to rotate around the axis of the grinding head rotation axis 64.

[0070] The circumference of the revolution is determined by the sliding distance of the grinding head 61 driven by the feed slide 62 along the radial direction of the grinding head's rotation.

[0071] Specifically, this invention achieves the rotation of the grinding head 61 and its adjustable circumferential revolution through the grinding head revolution axis 63, feed slide 62, and grinding head rotation axis 64 within the grinding head processing unit. It is understood that when processing thin-walled workpieces, excessive grinding force may cause deformation or warping of the thin-walled portion. By precisely controlling the radial feed of the grinding head 61, fine grinding depth adjustment can be achieved, avoiding irreversible deformation of the thin-walled workpiece due to excessive grinding force. The circumferential radius of revolution is determined according to the sliding distance of the feed slide 62, allowing the grinding head 61 to flexibly adjust its revolution radius when processing thin-walled workpieces. This avoids significant impact on the thin-walled workpiece due to sudden changes in processing parameters, ensuring the stability of the processing process.

[0072] Please continue reading. Figure 4 As shown, it is a structural schematic diagram of the workpiece cradle in an embodiment of the present invention. The cradle body 8 is also provided with a workpiece spindle 10 for carrying the workpiece to be processed, so that the workpiece spindle 10 drives the workpiece to be processed to rotate.

[0073] Specifically, the process control unit is used to determine the stress unit vector based on the contact stress value between the shaft and the bearing;

[0074] Wherein, the endpoint of the stress unit vector is the location of the maximum contact stress at the contact position between the shaft and the bearing, and the starting position of the stress unit vector is the center of the bearing.

[0075] Specifically, this invention uses vector form to represent the real-time contact stress between the shaft and the bearing. It can be understood that during the processing, the stress state will change continuously as the processing progresses. The stress unit vector can capture these changes in real time, intuitively showing the distribution characteristics of the contact stress in the contact area. In different processing stages, the change of the stress unit vector can reflect the change of stress distribution. Thus, in the long and complex processing process, real-time analysis of the processing parameters is realized.

[0076] Specifically, the process control unit is used to determine the change of the stress unit vector over time, wherein,

[0077] The process control unit is used to obtain the stress unit vector corresponding to a certain number of times within a preset monitoring period, and to determine the maximum angle between two stress unit vectors based on the stress unit vectors corresponding to the certain number of times.

[0078] In this embodiment, the duration of the preset monitoring cycle can be 5 seconds. Within the preset monitoring cycle of 5 seconds, the corresponding stress unit vector is acquired every 1 second. The interval between adjacent preset monitoring cycles can be 3 seconds.

[0079] Please see Figure 5 The diagram shown is a logic flowchart of a process control unit in an embodiment of the present invention determining whether a preset monitoring period is a processing feature period. The process control unit is further configured to determine whether the preset monitoring period is a processing feature period.

[0080] If the maximum included angle meets the characteristic phenomenon screening conditions, the process control unit determines that the preset monitoring period is the processing characteristic period;

[0081] If the maximum included angle does not meet the characteristic phenomenon screening conditions, the process control unit determines that the preset monitoring cycle is not a processing characteristic cycle.

[0082] The characteristic phenomenon screening condition is that the maximum included angle between two stress unit vectors at any end of the support frame 7 exceeds a preset included angle threshold within a preset monitoring period.

[0083] Specifically, those skilled in the art can determine the preset included angle threshold according to the precision requirements of the processing. The higher the precision requirements, the smaller the included angle threshold. In this embodiment, the included angle threshold ranges from [3° to 8°]. Preferably, the included angle threshold can be 5°.

[0084] Specifically, this invention selects processing characteristic cycles during the processing of thin-walled parts. It is understood that thin-walled workpieces are highly susceptible to deformation due to stress. By determining the processing characteristic cycle, the change of the stress unit vector over time can be monitored in real time, thereby understanding the stress state change trend of the thin-walled part at different times. When the maximum included angle exceeds the included angle threshold, it indicates that the part may have a large risk of deformation within that processing characteristic cycle, which facilitates timely adjustment of processing parameters to reduce part deformation. Thus, it enables adaptive adjustment of processing parameters for special processing time periods based on real-time analysis of processing parameters, improving the processing effect and accuracy of thin-walled workpieces.

[0085] Specifically, the process control unit is also used to determine the characteristic angle of the stress unit vector in the spatial dimension, wherein,

[0086] Under the condition that the preset monitoring period is the processing characteristic period, the process control unit obtains the stress unit vectors corresponding to each end of the support frame 7 at several times within the preset monitoring period, and determines the included angle between the two stress unit vectors at both ends of the support frame 7 at the same time as the characteristic characterization angle.

[0087] Specifically, the process control unit is also used to determine whether to adjust the single sliding distance of the feed slide 62, wherein,

[0088] The process control unit calculates the standard deviation of the included angle based on the characteristic included angle at several times. If the standard deviation of the included angle exceeds the preset standard deviation reference value, the process control unit determines to adjust the single sliding distance of the feed slide 62.

[0089] If the standard deviation of the included angle does not exceed the preset reference value for the standard deviation of the included angle, the process control unit determines not to adjust the single sliding distance of the feed slide 62;

[0090] Specifically, those skilled in the art can set the reference value of the included angle standard deviation according to the precision requirements of the processing. The higher the precision requirements, the smaller the reference value of the included angle standard deviation. In this embodiment, the range of the reference value of the included angle standard deviation is [2°, 5°]. Preferably, the reference value of the included angle standard deviation can be 3°.

[0091] Specifically, this invention determines whether to adjust the single sliding distance of the feed slide 62 by determining the characteristic angle of the stress unit vector in the spatial dimension. It can be understood that during the processing of thin-walled parts, the stress distribution at both ends of the support frame 7 may be uneven. By determining the characteristic angle and the standard deviation of the angle, this difference in stress distribution can be reflected. When the standard deviation of the angle exceeds the reference value, it indicates that the stress distribution difference is large. Adjusting the single sliding distance of the feed slide 62 can make the processing force of the grinding head 61 on the part more reasonable, avoid the influence of uneven stress, and reduce the deformation of the part caused by uneven stress. In this way, it realizes the adaptive adjustment of processing parameters for special processing time periods based on the real-time analysis results of processing process parameters, thereby improving the processing effect and processing accuracy of thin-walled workpieces.

[0092] Specifically, the process control unit is used to adjust the single sliding distance of the feed slide 62, wherein,

[0093] The process control unit pre-acquires the target machining trajectory of the workpiece to be processed by the grinding head processing unit within the processing characteristic cycle, and determines the single sliding distance corresponding to the target machining trajectory at several times, and adjusts the single sliding distance based on the included angle standard deviation;

[0094] The single sliding distance is negatively correlated with the standard deviation of the included angle.

[0095] In practice, if the process control unit determines that the single sliding distances corresponding to the five moments within a processing characteristic cycle with a cycle length of 5 seconds for the target processing trajectory are 2.5mm, 2.8mm, 3.2mm, 1.8mm and 3mm respectively;

[0096] If the standard deviation of the included angle is 3.5°, then the single sliding distances corresponding to the 5 time points can be multiplied by the first adjustment factor A1 = 0.8 respectively, and the single sliding distances corresponding to the 5 time points are 2mm, 2.24mm, 2.56mm, 1.44mm and 2.4mm respectively;

[0097] If the standard deviation of the included angle is 4°, then the single sliding distances corresponding to the 5 time points can be multiplied by the second adjustment factor A2 = 0.7 respectively, and the single sliding distances corresponding to the 5 time points are 1.75mm, 1.96mm, 2.24mm, 1.26mm and 2.1mm respectively;

[0098] Of course, for those skilled in the art, other negative correlation calculation methods suitable for the negative correlation between the single sliding distance and the standard deviation of the included angle in this embodiment can be used as the methods selected in this embodiment. In addition, in order not to affect the final grinding effect of the grinding head, the grinding time can be extended to ensure that the grinding head 61 grinds the workpiece to be processed to the target effect with a smaller single sliding distance. This is well known to those skilled in the art and will not be described in detail here.

[0099] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0100] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-axis composite machining center, characterized in that, include: The frame includes a base and a crossbeam (2) disposed on the base; The moving component includes an X-axis moving mechanism, a Y-axis moving mechanism and a Z-axis moving mechanism. The X-axis moving mechanism includes a slide rail disposed at the front of the crossbeam and an X-axis slide saddle disposed on the slide rail. The Y-axis moving mechanism includes a slide rail disposed on the upper surface of the base and a Y-axis slide saddle disposed on the slide rail; The Z-axis moving mechanism includes a first Z-axis slide saddle and a second Z-axis slide saddle respectively disposed on slide rails on the surface of the X-axis slide saddle. A milling cutter processing unit is disposed on the first Z-axis slide saddle, and a grinding head processing unit is disposed on the second Z-axis slide saddle. The grinding head processing unit includes a grinding head and a feed slide that drives the grinding head to slide along the radial direction of the grinding head's rotation. A workpiece cradle, used to carry the workpiece to be processed, includes a support frame fixed on the Y-axis slide saddle and a cradle body. The two ends of the cradle body are connected to the support frame through a rotating shaft and bearings, so that the cradle body rotates about the axis of the rotating shaft. Stress detection units are respectively installed at both ends of the support frame to obtain the contact stress value between the bearing and the bushing; The process control unit is connected to the stress detection unit and the moving component, respectively, to determine the stress unit vector according to the contact stress at both ends of the support frame, and to adjust the single sliding distance of the feed slide according to the changes of the stress unit vector in the spatial and temporal dimensions.

2. The multi-axis composite machining center according to claim 1, characterized in that, A tool magazine for storing milling cutters is also provided on the side of the crossbeam near the milling cutter processing unit.

3. The multi-axis composite machining center according to claim 1, characterized in that, The grinding head processing unit also includes a grinding head revolution axis and a grinding head rotation axis. The grinding head revolution axis drives the grinding head on the feed slide to revolve around the axis of the grinding head revolution axis. The grinding head rotation axis is set on the feed slide to drive the grinding head to rotate around the axis of rotation of the grinding head as a reference; The circumference of the revolution is determined by the sliding distance of the grinding head along the radial direction of the grinding head's rotation, driven by the feed slide.

4. The multi-axis composite machining center according to claim 1, characterized in that, The cradle body is also provided with a workpiece spindle for carrying the workpiece to be processed, so that the workpiece spindle drives the workpiece to be processed to rotate.

5. The multi-axis composite machining center according to claim 1, characterized in that, The process control unit is used to determine the stress unit vector based on the contact stress value between the shaft and the bearing; Wherein, the endpoint of the stress unit vector is the location of the maximum contact stress at the contact position between the shaft and the bearing, and the starting position of the stress unit vector is the center of the bearing.

6. The multi-axis composite machining center according to claim 5, characterized in that, The process control unit is used to determine the change of the stress unit vector over time, wherein... The process control unit is used to obtain the stress unit vector corresponding to a certain number of times within a preset monitoring period, and to determine the maximum angle between two stress unit vectors based on the stress unit vectors corresponding to the certain number of times.

7. The multi-axis composite machining center according to claim 6, characterized in that, The process control unit is further used to determine whether the preset monitoring cycle is a processing characteristic cycle, wherein... If the maximum included angle meets the characteristic phenomenon screening conditions, the process control unit determines that the preset monitoring period is the processing characteristic period; The characteristic phenomenon screening condition is that the maximum included angle between two stress unit vectors at any end of the support frame exceeds a preset included angle threshold within a preset monitoring period.

8. The multi-axis composite machining center according to claim 7, characterized in that, The process control unit is also used to determine the characteristic angle of the stress unit vector in the spatial dimension, wherein... Under the condition that the preset monitoring period is the processing characteristic period, the process control unit obtains the stress unit vectors corresponding to each end of the support frame at several times within the preset monitoring period, and determines the included angle between the two stress unit vectors at both ends of the support frame at the same time as the characteristic characterization angle.

9. The multi-axis composite machining center according to claim 8, characterized in that, The process control unit is also used to determine whether to adjust the single sliding distance of the feed slide, wherein, The process control unit calculates the standard deviation of the included angle based on the characteristic included angle at several times. If the standard deviation of the included angle exceeds the preset reference value of the standard deviation of the included angle, the process control unit determines to adjust the single sliding distance of the feed slide.

10. The multi-axis composite machining center according to claim 9, characterized in that, The process control unit is used to adjust the single sliding distance of the feed slide, wherein, The process control unit pre-acquires the target machining trajectory of the workpiece to be processed by the grinding head processing unit within the processing characteristic cycle, and determines the single sliding distance corresponding to the target machining trajectory at several times, and adjusts the single sliding distance based on the included angle standard deviation; The single sliding distance is negatively correlated with the standard deviation of the included angle.

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