Multi-axis composite machining machine tool and intelligent control method thereof

Abstract

The present application relates to the technical field of compound machine tool, especially to a multi-axis compound machining machine tool and an intelligent control method thereof, comprising running the machining machine tool, establishing a tool spindle coordinate system and an internal grinding head spindle coordinate system; determining the error level of the machine tool positioning accuracy according to the coordinate difference of the coordinate system origin; determining the adjustment range and adjustment object according to the vector coordinates, adjusting the fast moving speed and feed speed of the moving module; obtaining a plurality of coordinate differences, judging the machine tool positioning level, recalling the judgment standard of the machine tool positioning accuracy error level; detecting the cutting force on the workpiece spindle, judging the tool wear degree and taking corresponding measures; analyzing the change trend of the cutting force, judging the consumption level of the tool wear consumption according to the change trend of the cutting force, and adjusting the ratio of the spindle speed and the feed speed. The present application completes multiple processes by one clamping, adjusts the machining parameters of the machine tool, and significantly improves the positioning accuracy and machining efficiency of the machine tool.

Description

Technical Field

[0001] This invention relates to the field of composite machine tool technology, and in particular to a multi-axis composite machining tool and its intelligent control method. Background Technology

[0002] With increasing demands for processing efficiency, precision, and cost reduction, composite machining is being increasingly applied across various fields, representing a significant technological development direction for CNC machine tools. Composite functions can greatly eliminate transportation, clamping, and waiting time in discrete machining processes. Workpieces only require one clamping and positioning on the machine tool, reducing auxiliary processing time and improving machining accuracy, thus significantly shortening the processing cycle and reducing work-in-process inventory in the machining workshop. High-end five-axis CNC systems are the "most powerful brain" of the machine tool industry, essential cutting-edge equipment for high-end manufacturing. Moreover, five-axis CNC machine tools outperform three-axis machine tools in terms of machining accuracy, efficiency, consistency, and stability. Therefore, more and more customers, especially those in precision manufacturing, are choosing five-axis products. The rapid development of China's manufacturing industry has created a strong demand for five-axis CNC, and high-end five-axis CNC machine tools will see even more widespread application in the future.

[0003] Chinese Patent Publication No. CN113070691A discloses a multi-spindle milling and grinding composite machine tool. This multi-spindle milling and grinding composite machine tool uses a workpiece spindle to clamp the workpiece once, and then uses a rotary table to rotate to perform processing through a first grinding wheel spindle, a tool spindle, or a second grinding wheel spindle, so as to adapt to the processing needs of different stations on the workpiece. The first grinding wheel spindle can be rotated through the A-axis to adjust the helix angle for thread processing. The tool spindle can replace various tools to meet different processing needs. Thus, this composite machine tool can achieve a more comprehensive matching of workpiece processing needs through the interchange of at least four stations on the rotary table. Multi-dimensional processing can be achieved by adjusting the workpiece spindle with minimal amplitude, and the processing accuracy of the workpiece can be significantly improved.

[0004] Therefore, the multi-spindle milling and grinding composite machine tool has the following problems: during the machining of the workpiece and after switching milling and grinding processes and changing the tool spindle, the relative position of the tool to the workpiece may be deviated due to the influence of grinding and errors, and the positioning accuracy is not accurate enough. Summary of the Invention

[0005] To address this issue, the present invention provides a multi-axis composite machining center and its intelligent control method, which overcomes the problem in the prior art that the relative position of the tool to the workpiece may deviate due to grinding and errors during the machining process, as well as after switching milling and grinding operations and changing the tool spindle, resulting in insufficient positioning accuracy.

[0006] To achieve the above objectives, the present invention provides an intelligent control method for a multi-axis composite machining center, comprising:

[0007] Step S1: Control the processing unit to perform a trial run on a right-angled trapezoidal base, and establish the tool spindle coordinate system and the internal grinding head spindle coordinate system based on the tool spindle and the internal grinding head spindle in the processing unit;

[0008] Step S2: The machining unit is moved by the linkage control of the X-axis moving module, Y-axis moving module and Z-axis moving module. The moving unit is judged to have a moving error based on the coordinate difference of the coordinate system origin. The error level of the machine tool positioning accuracy is determined based on the difference evaluation value.

[0009] Step S3: Calculate the vector coordinates between the origins of the coordinate system, adjust the rapid traverse speed and feed speed of the moving module in the moving unit, and determine the adjustment range and adjustment object based on the coordinate values ​​in the vector coordinates;

[0010] Step S4: Obtain several coordinate differences, determine the positioning level of the machine tool's repeatability, and use the average value of the several coordinate differences to call back the evaluation criteria for the error level of the machine tool's positioning accuracy.

[0011] Step S5: Select the required cutting tool in the processing unit and process it through the processing unit. During the processing of the workpiece held on the cradle, the cutting force on the spindle of the workpiece in the cradle is detected, the degree of tool wear of the tool spindle and the spindle of the internal grinding head in the processing unit is determined, and corresponding measures are taken according to the degree of tool wear.

[0012] Step S6: Analyze the trend of cutting force changes, determine the wear level of the tool based on the trend of cutting force changes, and adjust the ratio of the spindle speed and feed rate of the tool spindle and the internal grinding head spindle.

[0013] Furthermore, before processing the workpiece, the machine tool is test-run to establish the tool spindle coordinate system and the internal grinding head spindle coordinate system;

[0014] The method for constructing the tool spindle coordinate system is as follows: the center of the tool spindle is taken as the origin, the direction from the origin to the automatic tool changer is the negative X-axis, the direction from the origin to the workpiece is the positive Y-axis, and the direction perpendicular to the origin and upward is the positive Z-axis.

[0015] The method for constructing the coordinate system of the internal grinding head spindle is as follows: the center of the spindle of the internal grinding head spindle is taken as the origin, the direction from the origin to the automatic tool changer is the negative X-axis, the direction from the origin to the workpiece is the positive Y-axis, and the direction perpendicular to the origin and upward is the positive Z-axis.

[0016] Furthermore, after the trial run of the switching process, the coordinate difference between the origin of the tool spindle coordinate system and the origin of the internal grinding head spindle coordinate system is calculated;

[0017] If the coordinate difference is less than or equal to the difference evaluation value, it is determined that the movement error of the moving unit is within the allowable range of positioning error, and the positioning accuracy of the machine tool is at the first error level.

[0018] If the coordinate difference is greater than the difference evaluation value, it is determined that the movement error of the moving unit exceeds the allowable range of positioning error, and the machine tool positioning accuracy is at the second error level.

[0019] Furthermore, when the machine tool positioning accuracy is at the second error level, the vector coordinates between the origin coordinates are calculated, and the vector coordinates include the horizontal coordinate, the vertical coordinate, and the longitudinal coordinate.

[0020] If the horizontal coordinate is positive, then increase the X-axis rapid movement speed of the X-axis movement module;

[0021] If the horizontal coordinate is negative, the X-axis rapid movement speed of the X-axis movement module is reduced. The increase or decrease in the X-axis rapid movement speed is proportional to the absolute value of the horizontal coordinate.

[0022] If the longitudinal coordinate is positive, then increase the Y-axis rapid traverse speed of the Y-axis movement module;

[0023] If the longitudinal coordinate is negative, the Y-axis traverse speed of the Y-axis moving module is reduced. The increase or decrease in the Y-axis traverse speed is proportional to the absolute value of the longitudinal coordinate.

[0024] If the vertical coordinate is positive, then increase the Z-axis feed speed of the Z-axis movement module;

[0025] If the vertical coordinate is negative, the Z-axis feed speed of the Z-axis moving module is reduced. The increase or decrease in the Z-axis feed speed is proportional to the absolute value of the vertical coordinate.

[0026] At the same time, the position of the spindle of the internal grinding head is adjusted according to the horizontal, vertical and other coordinates in the vector coordinate system.

[0027] Furthermore, the coordinate difference is calculated by switching processes multiple times a preset number of times, and the average difference between several coordinate differences is calculated.

[0028] If the average difference is less than or equal to the standard value, the machine tool's repeatability is judged to be in the first positioning level.

[0029] If the average difference is greater than the standard value, the machine tool's repeatability is judged to be at the second positioning level, and the difference evaluation value is adjusted back.

[0030] Furthermore, by using a force sensor installed on the workpiece spindle, the cutting force on the workpiece spindle is detected in real time, the cutting force variation curve over time is plotted, and the derivative function of the cutting force variation curve is calculated accordingly.

[0031] If the cutting force in the cutting force variation curve at any given moment is less than or equal to the critical value, then the tool wear is determined to be at the first wear level.

[0032] If the cutting force in the cutting force variation curve is greater than the critical value at any given moment, it is determined that the tool wear is at the second wear level, and a signal is issued to replace the tool.

[0033] Furthermore, when the tool wear is at the first wear level, if the derivative value of the cutting force change curve at any moment is less than zero, it is determined that the cutting force continues to decrease and the tool wear consumption is at the first consumption level.

[0034] If the derivative value of the cutting force change curve is greater than zero at any moment, it is determined that the cutting force continues to increase and the tool wear is at the second wear level.

[0035] When the tool wear is at the second wear level, it is determined that the spindle speed and feed rate of the tool spindle or internal grinding head spindle are mismatched, and the ratio of spindle speed to feed rate is increased.

[0036] A multi-axis composite machining center, characterized in that it comprises:

[0037] The base, which is a right-angled trapezoidal shape that is narrower at the top and wider at the bottom, is used to support the various unit components of the machining tool;

[0038] The moving unit, located at the top of the base and connected to the base, is capable of moving the processing unit in the X, Y, and Z directions.

[0039] The machining unit, which is connected to the moving unit, includes a tool magazine support, an automatic tool changer, a tool spindle, a B-axis rotary table, and an internal grinding head spindle, and can perform different machining processes on the workpiece through the linkage of several axes;

[0040] The cradle, which adopts a trapezoidal groove structure, is located at the top of the Y-axis moving module. The bottom of the cradle is provided with a guide rail mounting seat, which has an adjustable locking device. The middle of the cradle is provided with a workpiece spindle for clamping the workpiece to be processed and cooling it.

[0041] The mobile unit includes,

[0042] The X-axis moving module is installed on the trapezoidal top of the base. The mounting surface near the trapezoidal inclined surface of the base is concave. A groove is provided on the concave side of the concave shape. The X-axis moving module is used to move the processing unit in the X direction.

[0043] The Y-axis moving module is installed on the trapezoidal inclined surface of the base and has a rectangular cavity inside. The Y-axis moving module is used to move the processing unit in the Y direction.

[0044] The Z-axis moving module is vertically disposed in front of the concave side of the X-axis moving module and can slide on the X-axis moving module in the X direction to move the processing unit in the Z direction.

[0045] Furthermore, the X-axis moving module is provided with three X-axis linear guides in the same plane. The plane in which the X-axis linear guides are located is perpendicular to the mounting bottom surface of the X-axis moving module. The Z-axis moving module slides on the X-axis moving module through the X-axis linear guides.

[0046] The Y-axis moving module has a recessed rectangular cavity inside. The rectangular cavity is surrounded by wall panels and has a bottom plate. The upper part of the rectangular cavity is open, and two Y-axis guide rails are provided at the top of the rectangular cavity.

[0047] The Z-axis moving module is vertically equipped with four Z-axis linear guides. The processing unit moves in the Z-axis direction via the Z-axis linear guides. The Z-axis linear guides are equipped with Z1 slide saddles and Z2 slide saddles, which are driven by lead screws and can be independently controlled.

[0048] Furthermore, the automatic tool changer is disc-shaped and located on the upper side of the X-axis moving module. It is connected to the X-axis moving module through the tool magazine bracket and is used to accommodate several tools that can be mounted on the tool spindle.

[0049] The B-axis turntable is connected to the Z1 slide saddle via a circular mounting seat. The B-axis turntable can rotate around the Y-axis, enabling precise positioning and locking at any angle.

[0050] The tool spindle is mounted on the B-axis rotary table and connected to the Z1 slide saddle via the B-axis rotary table. The tool spindle can move in conjunction with the moving unit to perform axial feed and process the workpiece at different processes and angles.

[0051] The spindle of the internal grinding head is mounted on the Z2 slide saddle. It can control the movement of the grinding wheel of the internal grinding head relative to the inner axis of the workpiece through axial feed, adjust it in the radial direction, change the contact position between the grinding wheel and the inner surface of the workpiece, and also change the contact angle of the grinding wheel by rotation and tilting.

[0052] Furthermore, the X-direction linear guide rail is divided into an X-direction first guide rail, an X-direction second guide rail, and an X-direction third guide rail from bottom to top. The distance between the X-direction first guide rail and the X-direction second guide rail is smaller than the distance between the X-direction second guide rail and the X-direction third guide rail. A lead screw mounting position is provided between the X-direction first guide rail and the X-direction second guide rail. The X-direction drive motor of the lead screw is on the same side as the automatic tool changer.

[0053] The Y-axis guide rail is divided into a first Y-axis guide rail and a second Y-axis guide rail. The Y-axis lead screw is installed on the inner side of one of the Y-axis guide rails. The Y-axis drive motor of the Y-axis lead screw is installed in the middle and rear part of the base, located in the concave position of the U-shaped X-axis moving module.

[0054] The Z-axis linear guide is divided into a Z1-axis first guide, a Z1-axis second guide, a Z2-axis first guide, and a Z2-axis second guide. A Z1-axis lead screw is installed between the Z1-axis first guide and the Z1-axis second guide, and a Z2-axis lead screw is installed between the Z2-axis first guide and the Z2-axis second guide. The Z-axis drive motors of the Z1-axis lead screw and the Z2-axis lead screw are installed on the top of the Z-axis moving module. The Z1 slide saddle is installed on the Z1-axis first guide and the Z1-axis second guide, and the Z2 slide saddle is installed on the Z2-axis first guide and the Z2-axis second guide.

[0055] Furthermore, the X-axis moving module has a forward-protruding mounting foot on each of its lower left and right sides, and the mounting foot is disposed on the concave mounting seat of the base.

[0056] The X-axis slide saddle is mounted on the X-axis linear guide rail, and a shim for adjusting the perpendicularity of the X-axis and Z-axis is provided on the side of the mounting position of the X-axis linear guide rail.

[0057] The Z-axis moving module is slidably disposed in front of the X-axis moving module, and the Y-axis moving module is fixedly connected to the trapezoidal inclined surface of the base.

[0058] Compared with the prior art, the beneficial effects of the present invention are as follows: During the machining process, after the tool spindle performs the drilling operation on the workpiece, the internal grinding head spindle needs to perform internal grinding on the drilled hole. The positioning accuracy after switching tools and switching operations needs to be guaranteed. This method establishes a coordinate system based on the center points of the tool spindle and the internal grinding head spindle. After switching tools and switching operations, the error level of the machine tool positioning accuracy is determined by the coordinate difference between the origin coordinates of one coordinate system before the movement and the origin coordinates of the other coordinate system after the movement. When there is a difference between the coordinates of the origin of the tool spindle coordinate system and the internal grinding head spindle coordinate system after the switching operation, it indicates that there is a deviation between the position of the tool spindle and the machining position of the internal grinding head spindle on the workpiece. This method can detect the positioning accuracy of the machine tool in real time, without being limited by the operation requirements and detection accuracy of the detection instruments. It improves the efficiency and accuracy of detecting the positioning accuracy of the machine tool, avoids the machine tool machining the workpiece with low positioning accuracy due to low detection efficiency, and reduces the impact on the machining accuracy of the machine tool.

[0059] Furthermore, when vertically drilling and internal grinding are performed on a workpiece surface perpendicular to the workpiece, the lateral and longitudinal coordinates in the X and Y directions determine whether there is a deviation in the machining position between the two processes after switching processes, and the vertical coordinate in the Z direction determines whether the machining depth of the two processes is the same. This method adjusts the rapid traverse speed in the X and Y directions based on the vector coordinates between the origin coordinates, which has a calibrating effect on the rapid traverse speed of the machine tool and reduces the deviation in the machining position to within the allowable error range. At the same time, the feed speed in the Z direction is adjusted according to the vertical coordinates to avoid the workpiece being not ground to the required depth during internal grinding, which would have an adverse effect on the finished product. Correspondingly, the position of the origin coordinates of the internal grinding head spindle is adjusted according to the vector coordinates, which can significantly improve the positioning accuracy and calibration effect of the machine tool, and improve the machining efficiency and accuracy.

[0060] Furthermore, repeatability of positioning accuracy reflects the consistency and repeatability of a machine tool reaching the target position in multiple movements. This method judges the fluctuation of machine tool positioning accuracy by calculating the average difference between several coordinate differences. By reducing the difference evaluation value, the evaluation criteria for judging the error level of machine tool positioning accuracy becomes more stringent, thereby further improving the positioning accuracy and calibration effect of the machining tool.

[0061] Furthermore, a mismatch between spindle speed and feed rate can lead to accelerated tool wear or increased internal grinding temperature causing thermal deformation and decreased workpiece machining accuracy. This method adjusts the spindle speed accordingly after a change in feed rate and collects cutting force signals in real time using a force sensor mounted on the workpiece spindle. It analyzes the trend of cutting force changes to indirectly assess tool wear. Based on the degree of tool wear and wear consumption level, it determines whether the spindle speed and feed rate are matched, avoiding accelerated tool wear caused by a mismatch between spindle speed and feed rate. This increases the flexibility and adaptability of checking the machining parameters of the machine tool during the machining process.

[0062] Furthermore, the automatic tool changer adopts a disc-type design, capable of accommodating multiple tools. A robotic arm retrieves the tools from the magazine and automatically installs them onto the spindle for machining. A computer control system intelligently selects the required tool. The automatic positioning system, through an integrated robotic arm and automatic tool changer, automatically completes workpiece positioning and clamping between different machining operations, reducing manual operation. The automatic positioning system includes a multi-axis linkage positioning platform and uses vision and force sensors for real-time monitoring and adjustment to ensure accurate workpiece positioning.

[0063] Furthermore, the core component of the internal grinding head spindle is the grinding head spindle itself, on which grinding wheels are mounted. The spindle is typically driven by an electric motor to rotate at high speed. The rotation of the grinding wheels generates grinding force, which acts directly on the inner cylindrical surface of the workpiece for removal processing. The internal grinding head spindle controls the movement of the grinding wheels relative to the inner cylindrical axis of the workpiece through axial feed, and adjusts in the radial direction, that is, changes the contact position between the grinding wheels and the inner surface of the workpiece to achieve grinding at different depths. It can also change the contact angle of the grinding wheels by rotating and tilting, enabling it to perform multi-angle grinding on the inner cylindrical surface of the workpiece, ensuring efficient processing of complex inner cylindrical shapes or deep holes, and performing fine grinding.

[0064] Furthermore, the five-axis linkage function of the internal grinding head spindle allows for independent adjustment and positioning in multiple directions. Compared to ordinary grinding heads that can only move in a single plane, the internal grinding head spindle can more flexibly adapt to the grinding requirements of complex workpieces and handle more complex workpiece shapes. The Z1 and Z2 slides are driven by the Z1 and Z2 lead screws respectively, and their motion can be independently controlled. The left-right relative positions of the Z1 and Z2 slides are not limited to the current example and can be interchanged. The integrated milling and grinding characteristic of the tool spindle and the internal grinding head spindle allows the workpiece to undergo both milling and grinding operations in a fixed position, reducing workpiece transfer errors and improving machining accuracy. Combining the advantages of milling and grinding, roughing and finishing can be completed in the same process, ensuring consistent workpiece surface quality, making it particularly suitable for machining tasks requiring high precision and high surface quality. Attached Figure Description

[0065] Figure 1 This is a flowchart of an intelligent control method for a multi-axis composite machining center according to an embodiment of the present invention;

[0066] Figure 2 This is a schematic diagram of the structure of a multi-axis composite machining center according to an embodiment of the present invention;

[0067] Figure 3 This is a schematic diagram of the structure of the base and the moving unit in an embodiment of the present invention;

[0068] Figure 4 This is a schematic diagram of the Z-axis moving module in an embodiment of the present invention;

[0069] Figure 5 This is a schematic diagram of the tool spindle and B-axis rotary table in the machining unit of this embodiment of the invention;

[0070] Figure 6 This is a schematic diagram of the structure of the inner grinding head spindle and Z2 slide saddle in the processing unit of this invention embodiment;

[0071] Figure 7 This is a schematic diagram of the cradle structure in an embodiment of the present invention;

[0072] In the diagram: 1-Base, 2-X-axis moving module, 3-Y-axis moving module, 4-Z-axis moving module, 6-Cradle, 21-First X-axis guide rail, 22-Second X-axis guide rail, 23-Third X-axis guide rail, 24-Screw mounting position, 25-X-axis drive motor, 26-Y-axis drive motor, 27-Z-axis drive motor, 31-First Y-axis guide rail, 32-Second Y-axis guide rail, 33-Y-axis drive motor, 41-First Z1-axis guide rail, 42-Second Z1-axis guide rail, 43-First Z2-axis guide rail, 44-Second Z2-axis guide rail, 45-Z1 slide saddle, 46-Z2 slide saddle, 51-Tool magazine bracket, 52-Automatic tool changer magazine, 53-Tool spindle, 54-B-axis rotary table, 55-Internal grinding head spindle, 61-Guide rail mounting seat, 62-Workpiece spindle. Detailed Implementation

[0073] 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.

[0074] 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.

[0075] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying 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.

[0076] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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.

[0077] Please see Figures 1-7 As shown, Figure 1 This is a flowchart of an intelligent control method for 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 a multi-axis composite machining center according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the base and the moving unit in an embodiment of the present invention; Figure 4 This is a schematic diagram of the Z-axis moving module in an embodiment of the present invention; Figure 5 This is a schematic diagram of the tool spindle and B-axis rotary table in the machining unit of this embodiment of the invention; Figure 6 This is a schematic diagram of the structure of the inner grinding head spindle and Z2 slide saddle in the processing unit of this invention embodiment; Figure 7 This is a schematic diagram of the cradle structure in an embodiment of the present invention.

[0078] This invention provides an intelligent control method for a multi-axis composite machining center, comprising:

[0079] Step S1: Control the processing unit to perform a trial run on a right-angled trapezoidal base, and establish the tool spindle coordinate system and the internal grinding head spindle coordinate system based on the tool spindle and the internal grinding head spindle in the processing unit;

[0080] Step S2: The machining unit is moved by the linkage control of the X-axis moving module, Y-axis moving module and Z-axis moving module. The moving unit is judged to have a moving error based on the coordinate difference of the coordinate system origin. The error level of the machine tool positioning accuracy is determined based on the difference evaluation value.

[0081] Step S3: Calculate the vector coordinates between the origins of the coordinate system, adjust the rapid traverse speed and feed speed of the moving module in the moving unit, and determine the adjustment range and adjustment object based on the coordinate values ​​in the vector coordinates;

[0082] Step S4: Obtain several coordinate differences, determine the positioning level of the machine tool's repeatability, and use the average value of the several coordinate differences to call back the evaluation criteria for the error level of the machine tool's positioning accuracy.

[0083] Step S5: Select the required cutting tool in the processing unit and process it through the processing unit. During the processing of the workpiece held on the cradle, the cutting force on the spindle of the workpiece in the cradle is detected, the degree of tool wear of the tool spindle and the spindle of the internal grinding head in the processing unit is determined, and corresponding measures are taken according to the degree of tool wear.

[0084] Step S6: Analyze the trend of cutting force changes, determine the wear level of the tool based on the trend of cutting force changes, and adjust the ratio of the spindle speed and feed rate of the tool spindle and the internal grinding head spindle.

[0085] In this embodiment, when the tool spindle 53 is drilling the workpiece, the tool spindle first moves to the required position and drills the workpiece. After that, the internal grinding head spindle 55 moves to the same required position to perform internal grinding on the drilled hole of the workpiece.

[0086] Before machining the workpiece, the machine tool is test-run to establish the tool spindle coordinate system and the internal grinding head spindle coordinate system.

[0087] The trial run includes the process of switching between the tool spindle 53 and the internal grinding head spindle 55, as well as controlling the movement of the tool spindle and the internal grinding head spindle in the X, Y, and Z directions.

[0088] Specifically, the method for constructing the tool spindle coordinate system is as follows: the spindle center of the tool spindle 53 is taken as the origin, the direction from the origin to the automatic tool changer 52 is the negative X-axis, the direction from the origin to the workpiece is the positive Y-axis, and the direction perpendicular to the origin upwards is the positive Z-axis.

[0089] The method for constructing the coordinate system of the internal grinding head spindle is as follows: the center of the spindle of the internal grinding head spindle 55 is taken as the origin, the direction from the origin to the automatic tool changer 52 is the negative X-axis, the direction from the origin to the workpiece is the positive Y-axis, and the direction perpendicular to the origin and upward is the positive Z-axis.

[0090] After the trial run and process switching, calculate the coordinate difference between the origin of the tool spindle coordinate system and the origin of the internal grinding head spindle coordinate system.

[0091] Specifically, when switching processes, the tool spindle coordinate system and the internal grinding head spindle coordinate system move. After the movement stops, the tool spindle coordinate system and the internal grinding head spindle coordinate system have the origin coordinates before the movement and the origin coordinates of the other coordinate system after the movement.

[0092] The origin coordinates of the internal grinding head spindle coordinate system can be obtained in the tool spindle coordinate system, or the origin coordinates of the tool spindle coordinate system can be obtained in the internal grinding head spindle coordinate system. The coordinate difference is calculated based on the origin coordinates before the movement and the origin coordinates of the other coordinate system after the movement. The coordinate difference is equal to the distance between the two origin coordinates.

[0093] If the coordinate difference is less than or equal to the difference evaluation value, it is determined that the movement error of the moving unit is within the allowable range of positioning error, and the positioning accuracy of the machine tool is at the first error level.

[0094] If the coordinate difference is greater than the difference evaluation value, it is determined that the movement error of the moving unit exceeds the allowable range of positioning error, and the machine tool positioning accuracy is at the second error level.

[0095] The difference evaluation value is equal to 0.08 mm.

[0096] Specifically, during the machining process, after the tool spindle 53 performs a drilling operation on the workpiece, the internal grinding head spindle 55 needs to perform internal grinding on the drilled hole. The positioning accuracy after switching tools and changing operations needs to be guaranteed. This method establishes a coordinate system based on the center points of the tool spindle and the internal grinding head spindle. After switching tools and changing operations, the error level of the machine tool positioning accuracy is determined by the coordinate difference between the origin coordinates of one coordinate system before the movement and the origin coordinates of the other coordinate system after the movement. When there is a difference between the coordinates of the origin of the tool spindle coordinate system and the internal grinding head spindle coordinate system after the operation, it indicates that there is a deviation between the position of the tool spindle and the machining position of the internal grinding head spindle on the workpiece. This method can detect the positioning accuracy of the machine tool in real time, without being limited by the operation requirements and detection accuracy of the detection instruments. It improves the efficiency and accuracy of detecting the positioning accuracy of the machine tool, avoids the machine tool machining the workpiece with low positioning accuracy due to low detection efficiency, and reduces the impact on the machining accuracy of the machine tool.

[0097] When the machine tool positioning accuracy is at the second error level, the vector coordinates (X0, Y0, Z0) between the origin coordinates are calculated. The method for calculating the vector coordinates is existing technology and will not be elaborated here.

[0098] X0 is the horizontal coordinate of the vector coordinate, Y0 is the vertical coordinate of the vector coordinate, and Z0 is the vertical coordinate of the vector coordinate.

[0099] If the horizontal coordinate is positive, the X-axis rapid movement speed of the X-axis movement module 2 is increased, and the increase in the X-axis rapid movement speed is proportional to the absolute value of the horizontal coordinate.

[0100] If the horizontal coordinate is negative, the X-axis fast traverse speed of the X-axis movement module 2 is reduced, and the reduction in the X-axis fast traverse speed is proportional to the absolute value of the horizontal coordinate.

[0101] If the longitudinal coordinate is positive, the Y-axis rapid movement speed of the Y-axis movement module 3 is increased, and the increase in the Y-axis rapid movement speed is proportional to the absolute value of the longitudinal coordinate.

[0102] If the longitudinal coordinate is negative, the Y-axis fast traverse speed of the Y-axis moving module 3 is reduced, and the reduction in the Y-axis fast traverse speed is proportional to the absolute value of the longitudinal coordinate.

[0103] Meanwhile, when the machine tool positioning accuracy is at the second error level, the position of the origin coordinate of the internal grinding head spindle 55 is adjusted according to the horizontal, vertical and longitudinal coordinates in the vector coordinates.

[0104] In this embodiment, the moving speeds of the tool spindle 53 and the internal grinding head spindle 55 are divided into rapid traverse speed when switching tools or switching processes and feed speed when cutting, milling, drilling and internal grinding of the workpiece.

[0105] The rapid traverse speed and the feed speed are further divided into X-axis rapid traverse speed, Y-axis rapid traverse speed, Z-axis rapid traverse speed and X-axis feed speed, Y-axis feed speed, Z-axis feed speed.

[0106] It is understandable that the deviation direction and deviation distance between the tool spindle and the internal grinding head spindle can be calculated based on vector coordinates. Adjusting the position of the internal grinding head spindle according to the deviation direction and deviation distance is a mature existing technology, and will not be described in detail in this embodiment.

[0107] When the machine tool positioning accuracy is at the second error level

[0108] If the vertical coordinate is positive, the Z-axis feed speed of the Z-axis movement module 4 is increased, and the increase in the Z-axis feed speed is proportional to the absolute value of the vertical coordinate.

[0109] If the vertical coordinate is negative, the Z-axis feed speed of the Z-axis movement module 4 is reduced, and the reduction in the Z-axis feed speed is proportional to the absolute value of the vertical coordinate.

[0110] Specifically, when vertically drilling and internal grinding are performed on a workpiece perpendicular to its surface, the lateral and longitudinal coordinates in the X and Y directions determine whether there is a deviation in the machining position between the two processes after switching processes. The vertical coordinate in the Z direction determines whether the machining depths of the two processes are the same. This method adjusts the rapid traverse speed in the X and Y directions based on the vector coordinates between the origin coordinates, which calibrates the rapid traverse speed of the machine tool and reduces the deviation in the machining position to within the allowable error range. At the same time, the feed speed in the Z direction is adjusted according to the vertical coordinates to avoid the workpiece being damaged due to insufficient internal grinding depth. Correspondingly, the position of the origin coordinates of the internal grinding head spindle 55 is adjusted according to the vector coordinates, which can significantly improve the positioning accuracy and calibration effect of the machine tool, and improve machining efficiency and accuracy.

[0111] Calculate the coordinate difference by switching processes multiple times according to a preset number of times, and calculate the average difference among several coordinate differences.

[0112] If the average difference is less than or equal to the standard value, the machine tool's repeatability is judged to be in the first positioning level.

[0113] If the average difference is greater than the standard value, the machine tool's repeatability is judged to be at the second positioning level, the difference evaluation value is adjusted back, and the evaluation criteria for the positioning accuracy level are adjusted.

[0114] Specifically, the difference evaluation value is reduced based on the ratio of the standard value to the average difference value;

[0115] The standard value is 0.04 mm.

[0116] Specifically, repeatability of positioning accuracy reflects the consistency and repeatability of a machine tool reaching the target position in multiple movements. This method judges the fluctuation of machine tool positioning accuracy by calculating the average difference between several coordinate differences. By reducing the difference evaluation value, the evaluation criteria for judging the error level of machine tool positioning accuracy becomes more stringent, thereby further improving the positioning accuracy and calibration effect of the machining tool.

[0117] During implementation, the spindle speed is adjusted accordingly after adjusting the feed rate.

[0118] By using a force sensor installed on the workpiece spindle 62, the cutting force on the workpiece spindle 62 is detected in real time, the cutting force variation curve of the cutting force changing with time is plotted, and the derivative function of the cutting force variation curve is calculated accordingly.

[0119] If the cutting force in the cutting force variation curve at any given moment is less than or equal to the critical value, then the tool wear is determined to be at the first wear level.

[0120] If the cutting force in the cutting force variation curve is greater than the critical value at any time, it is determined that the tool wear is at the second wear level, and a signal is issued to replace the tool.

[0121] The critical value is a preset value set based on historical data of the cutting force experienced by the workpiece spindle.

[0122] Among them, when the tool wear is at the first wear level, if the derivative value of the cutting force change curve is less than zero at any moment, it is determined that the cutting force continues to decrease and the tool wear consumption is at the first consumption level.

[0123] If the derivative value of the cutting force change curve is greater than zero at any moment, it is determined that the cutting force continues to increase and the tool wear is at the second wear level.

[0124] When the tool wear is at the second wear level, it is determined that the spindle speed and feed rate of the tool spindle 53 or the internal grinding head spindle 55 are mismatched, and the ratio of spindle speed to feed rate is increased.

[0125] Specifically, a mismatch between spindle speed and feed rate can lead to accelerated tool wear or increased internal grinding temperature causing thermal deformation and reduced workpiece machining accuracy. This method adjusts the spindle speed accordingly after a change in feed rate and collects cutting force signals in real time using a force sensor mounted on the workpiece spindle 62. It analyzes the trend of cutting force changes to indirectly assess tool wear. Based on the degree of tool wear and wear consumption level, it determines whether the spindle speed and feed rate are matched, avoiding accelerated tool wear caused by a mismatch between spindle speed and feed rate. This increases the flexibility and adaptability of checking the machining parameters of the machine tool during machining.

[0126] This invention provides a multi-axis composite machining center, comprising:

[0127] The base 1 is a right-angled trapezoidal shape that is narrower at the top and wider at the bottom, and is used to support the various unit components of the processing machine tool;

[0128] The moving unit, located at the top of the base and connected to the base, is capable of moving the processing unit in the X, Y, and Z directions.

[0129] The processing unit, which is connected to the moving unit, includes a tool magazine support 51, an automatic tool changer 52, a tool spindle 53, a B-axis rotary table 54, and an internal grinding head spindle 55, and can perform different processing steps on the workpiece through the linkage of several axes.

[0130] Cradle 6, which adopts a trapezoidal groove structure, is located at the top of Y-axis moving module 3. The bottom of the cradle is provided with a guide rail mounting seat 61, which has an adjustable locking device. The middle of the cradle is provided with a workpiece spindle 62, which is used to clamp the workpiece to be processed and cool it.

[0131] The moving unit includes an X-axis moving module 2, which is installed on the trapezoidal top of the base. The mounting surface near the trapezoidal inclined surface of the base is concave, and a groove is provided on the concave side of the concave shape. The X-axis moving module is used to move the processing unit in the X direction.

[0132] Y-axis moving module 3 is installed on the trapezoidal inclined surface of the base and has a rectangular cavity inside. The Y-axis moving module is used to move the processing unit in the Y direction.

[0133] The Z-axis moving module 4 is vertically disposed in front of the concave side of the X-axis moving module and can slide on the X-axis moving module in the X direction to move the processing unit in the Z direction.

[0134] Furthermore, the X-axis moving module is provided with three X-axis linear guides in the same plane. The plane in which the X-axis linear guides are located is perpendicular to the mounting bottom surface of the X-axis moving module. The Z-axis moving module slides on the X-axis moving module through the X-axis linear guides.

[0135] The Y-axis moving module has a recessed rectangular cavity inside. The rectangular cavity is surrounded by wall panels and has a bottom plate. The upper part of the rectangular cavity is open, and two Y-axis guide rails are provided at the top of the rectangular cavity.

[0136] The Z-axis moving module is vertically equipped with four Z-axis linear guides. The processing unit moves in the Z-axis direction through the Z-axis linear guides. The Z-axis linear guides are equipped with Z1 slide saddle 45 and Z2 slide saddle 46. The Z1 slide saddle and Z2 slide saddle are driven by lead screws and can be independently controlled for motion.

[0137] Furthermore, the automatic tool changer is disc-shaped and located on the upper side of the X-axis moving module. It is connected to the X-axis moving module through the tool magazine bracket and is used to accommodate several tools that can be mounted on the tool spindle.

[0138] The B-axis turntable is connected to the Z1 slide saddle via a circular mounting seat. The B-axis turntable can rotate around the Y-axis, enabling precise positioning and locking at any angle.

[0139] The tool spindle is mounted on the B-axis rotary table and connected to the Z1 slide saddle via the B-axis rotary table. The tool spindle can move in conjunction with the moving unit to perform axial feed and process the workpiece at different processes and angles.

[0140] The spindle of the internal grinding head is mounted on the Z2 slide saddle. It can control the movement of the grinding wheel of the internal grinding head relative to the inner axis of the workpiece through axial feed, adjust it in the radial direction, change the contact position between the grinding wheel and the inner surface of the workpiece, and also change the contact angle of the grinding wheel by rotation and tilting.

[0141] Furthermore, the X-direction linear guide rail is divided into an X-direction first guide rail 21, an X-direction second guide rail 22, and an X-direction third guide rail 23 from bottom to top. The distance between the X-direction first guide rail and the X-direction second guide rail is smaller than the distance between the X-direction second guide rail and the X-direction third guide rail. A lead screw mounting position 24 is provided between the X-direction first guide rail and the X-direction second guide rail. The X-direction drive motor 25 of the lead screw is on the same side as the automatic tool changer.

[0142] The Y-axis guide rail is divided into a first Y-axis guide rail 31 and a second Y-axis guide rail 32. The Y-axis lead screw is installed on the inner side near one of the Y-axis guide rails. The Y-axis drive motor 26 of the Y-axis lead screw is installed in the middle and rear part of the base, located in the concave position of the U-shaped X-axis moving module.

[0143] The Z-axis linear guide is divided into a Z1-axis first guide rail 41, a Z1-axis second guide rail 42, a Z2-axis first guide rail 43, and a Z2-axis second guide rail 44. A Z1-axis lead screw is installed between the Z1-axis first guide rail and the Z1-axis second guide rail, and a Z2-axis lead screw is installed between the Z2-axis first guide rail and the Z2-axis second guide rail. The Z-axis drive motors 27 of the Z1-axis lead screw and the Z2-axis lead screw are installed on the top of the Z-axis moving module. The Z1 slide saddle is installed on the Z1-axis first guide rail and the Z1-axis second guide rail, and the Z2 slide saddle is installed on the Z2-axis first guide rail and the Z2-axis second guide rail.

[0144] Furthermore, the X-axis moving module has a forward-protruding mounting foot on each of its left and right sides below, and the mounting foot is disposed on the concave mounting seat of the base. The X-axis sliding saddle is mounted on the X-axis linear guide rail, and a shim for adjusting the perpendicularity of the X-axis and Z-axis is provided on the side of the mounting position of the X-axis linear guide rail.

[0145] The Z-axis moving module is slidably positioned in front of the X-axis moving module, and the Y-axis moving module is fixedly connected to the trapezoidal inclined surface of the base. Specifically, the automatic tool changer 52 adopts a disc-type design, capable of accommodating multiple tools. A robotic arm retrieves the tools from the tool magazine and automatically installs them onto the spindle for machining. The required tool is intelligently selected by a computer control system. The automatic positioning system, through an integrated robotic arm and automatic tool changer, automatically completes workpiece positioning and clamping between different machining processes, reducing manual operation. The automatic positioning system includes a multi-axis linkage positioning platform and uses vision and force sensors for real-time monitoring and adjustment to ensure accurate workpiece positioning.

[0146] The B-axis rotary table 54 can rotate around the Y-axis to achieve precise positioning and locking at any angle. The tool spindle 53 is installed on the end face of the B-axis rotary table 54, and the tool spindle 53 has an automatic tool changing function.

[0147] The core component of the internal grinding head spindle 55 is the grinding head spindle, on which grinding wheels are mounted. The spindle is typically driven by an electric motor to rotate at high speed. The rotation of the grinding wheels generates grinding force, which acts directly on the inner cylindrical surface of the workpiece for removal processing. The internal grinding head spindle 55 controls the movement of the grinding wheels relative to the inner cylindrical axis of the workpiece through axial feed, and adjusts in the radial direction, that is, changes the contact position between the grinding wheels and the inner surface of the workpiece to achieve grinding at different depths. It can also change the contact angle of the grinding wheels by rotating and tilting, so that it can perform multi-angle grinding on the inner cylindrical surface of the workpiece, ensuring efficient processing of complex inner cylindrical shapes or deep holes, and performing fine grinding.

[0148] The internal grinding head spindle 55 is equipped with a five-axis linkage function, enabling independent adjustment and positioning in multiple directions. Compared to ordinary grinding heads that can only move in a single plane, the internal grinding head spindle 55 can more flexibly adapt to the grinding requirements of complex workpieces and handle more complex workpiece shapes. The Z1 and Z2 slides 46 are driven by the Z1 and Z2 lead screws respectively, allowing for independent motion control. Furthermore, the left-right relative positions of the Z1 and Z2 slides 46 are not limited to the current example and can be interchanged. The integrated milling and grinding characteristic provided by the tool spindle 53 and the internal grinding head spindle 55 allows the workpiece to undergo both milling and grinding operations in a fixed position, reducing workpiece transfer errors and improving machining accuracy. Combining the advantages of milling and grinding, roughing and finishing can be completed in the same process, ensuring consistent workpiece surface quality, making it particularly suitable for machining tasks requiring high precision and high surface quality.

[0149] The cradle 6 structure incorporates built-in vibration damping devices and damping materials to absorb vibrations caused by cutting forces, the machining process, or external vibration sources. This effectively reduces high-frequency vibrations generated during machine tool operation, ensuring high-precision machining. The load-bearing components of the cradle 6 feature a reinforced structure and thickened design, supporting and evenly distributing loads from the worktable and spindle to enhance its load-bearing capacity. This ensures no deformation during high-speed, high-load machining and guarantees stability under prolonged high-load conditions. The bottom of the cradle 6 features a guide rail mounting base 61. The guide rail's mounting position is fixed using high-precision machining and measurement technology, ensuring a stable relative position during operation and reducing errors caused by grinding forces or external interference. The guide rail mounting base 61 has an adjustable locking device to ensure high-precision positioning of the guide rail during long-term use and effectively resist cutting forces generated during machining. The cradle 6 design employs thermal expansion compensation technology, combined with internal heat dissipation channels. A liquid cooling system controls the cradle 6's temperature changes in real time to reduce machining errors caused by thermal expansion. The heat dissipation system includes multiple heat dissipation pipes and a coolant circulation device, effectively reducing thermal deformation of the cradle 6 through a uniformly distributed heat dissipation design. Furthermore, the cradle 6 consists of multiple replaceable modules, including a support module, a vibration damping module, and a temperature control module. These modules can be flexibly configured and adjusted according to different machining requirements. Each module connects to other parts of the machine tool through standardized interfaces, simplifying maintenance and upgrades and improving the machine tool's flexibility and maintainability.

[0150] 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.

[0151] 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. An intelligent control method for a multi-axis composite machining center, characterized in that, include: The control processing unit is tested on a right-angled trapezoidal base. The tool spindle coordinate system and the internal grinding head spindle coordinate system are established based on the tool spindle and the internal grinding head spindle in the processing unit. The machining unit is moved by the linkage control of the X-axis movement module, Y-axis movement module and Z-axis movement module. The movement error of the moving unit is judged by the coordinate difference of the coordinate system origin. The error level of the machine tool positioning accuracy is determined by the difference evaluation value. The error level of the machine tool positioning accuracy is determined by the coordinate difference between the origin coordinates before the movement of one coordinate system and the origin coordinates after the movement of the other coordinate system. Calculate the vector coordinates between the origin of the coordinate system, adjust the rapid traverse speed and feed speed of the moving module in the moving unit, and determine the adjustment range and adjustment object based on the coordinate values ​​in the vector coordinates; Based on whether the coordinate difference is less than the difference evaluation value, it is determined that the movement error of the moving unit is within or exceeds the allowable range of positioning error, and the positioning accuracy of the machine tool is at the first error level or the second error level. When the machine tool positioning accuracy is at the second error level, calculate the vector coordinates between the origin coordinates, and adjust the rapid traverse speed of each moving module in the moving unit according to the vector coordinates; At the same time, the position of the spindle of the internal grinding head is adjusted according to the horizontal, vertical and vertical coordinates in the vector coordinate system; Obtain several coordinate differences, determine the positioning level of the machine tool's repeatability, and use the average value of the several coordinate differences to determine the evaluation criteria for the machine tool's positioning accuracy error level. Select the required cutting tools within the machining unit and perform machining through the machining unit. During the machining process of the workpiece clamped on the cradle, detect the cutting force on the spindle of the workpiece in the cradle, determine the degree of tool wear of the tool spindle and the spindle of the internal grinding head in the machining unit, and take corresponding measures according to the degree of tool wear. Analyze the trend of cutting force changes, determine the wear level of the tool based on the trend of cutting force changes, and adjust the ratio of spindle speed and feed rate of the tool spindle and the internal grinding head spindle.

2. The intelligent control method for a multi-axis composite machining center according to claim 1, characterized in that, Before machining the workpiece, the machine tool is test-run to establish the tool spindle coordinate system and the internal grinding head spindle coordinate system. The method for constructing the tool spindle coordinate system is as follows: the center of the tool spindle is taken as the origin, the direction from the origin to the automatic tool changer is the negative X-axis, the direction from the origin to the workpiece is the positive Y-axis, and the direction perpendicular to the origin and upward is the positive Z-axis. The method for constructing the coordinate system of the internal grinding head spindle is as follows: the center of the spindle of the internal grinding head spindle is taken as the origin, the direction from the origin to the automatic tool changer is the negative X-axis, the direction from the origin to the workpiece is the positive Y-axis, and the direction perpendicular to the origin and upward is the positive Z-axis. After the trial run of the switching process, calculate the coordinate difference between the origin of the tool spindle coordinate system and the origin of the internal grinding head spindle coordinate system; If the coordinate difference is less than or equal to the difference evaluation value, it is determined that the movement error of the moving unit is within the allowable range of positioning error, and the positioning accuracy of the machine tool is at the first error level. If the coordinate difference is greater than the difference evaluation value, it is determined that the movement error of the moving unit exceeds the allowable range of positioning error, and the machine tool positioning accuracy is at the second error level. When the machine tool positioning accuracy is at the second error level, calculate the vector coordinates between the origin coordinates, wherein the vector coordinates include the horizontal coordinate, the vertical coordinate, and the longitudinal coordinate; If the horizontal coordinate is positive, then increase the X-axis rapid movement speed of the X-axis movement module; If the horizontal coordinate is negative, the X-axis rapid movement speed of the X-axis movement module is reduced. The increase or decrease in the X-axis rapid movement speed is proportional to the absolute value of the horizontal coordinate. If the longitudinal coordinate is positive, then increase the Y-axis rapid traverse speed of the Y-axis movement module; If the longitudinal coordinate is negative, the Y-axis traverse speed of the Y-axis moving module is reduced. The increase or decrease in the Y-axis traverse speed is proportional to the absolute value of the longitudinal coordinate. If the vertical coordinate is positive, then increase the Z-axis feed speed of the Z-axis movement module; If the vertical coordinate is negative, the Z-axis feed speed of the Z-axis moving module is reduced. The increase or decrease in the Z-axis feed speed is proportional to the absolute value of the vertical coordinate. At the same time, the position of the spindle of the internal grinding head is adjusted according to the horizontal, vertical and vertical coordinates in the vector coordinate system; Calculate the coordinate difference by switching processes multiple times according to a preset number of times, and calculate the average difference among several coordinate differences. If the average difference is less than or equal to the standard value, the machine tool's repeatability is judged to be in the first positioning level. If the average difference is greater than the standard value, the machine tool's repeatability is judged to be at the second positioning level, and the difference evaluation value is adjusted back.

3. The intelligent control method for a multi-axis composite machining center according to claim 1, characterized in that, By using a force sensor installed on the workpiece spindle, the cutting force on the workpiece spindle is detected in real time, the cutting force variation curve over time is plotted, and the derivative function of the cutting force variation curve is calculated accordingly. If the cutting force in the cutting force variation curve at any given moment is less than or equal to the critical value, then the tool wear is determined to be at the first wear level. If the cutting force in the cutting force variation curve is greater than the critical value at any time, it is determined that the tool wear is at the second wear level, and a signal is issued to replace the tool. When the tool wear is at the first wear level, if the derivative value of the cutting force change curve is less than zero at any moment, it is determined that the cutting force continues to decrease and the tool wear is at the first wear level. If the derivative value of the cutting force change curve is greater than zero at any moment, it is determined that the cutting force continues to increase and the tool wear is at the second wear level. When the tool wear is at the second wear level, it is determined that the spindle speed and feed rate of the tool spindle or internal grinding head spindle are mismatched, and the ratio of spindle speed to feed rate is increased.

4. A multi-axis composite machining center employing the intelligent control method described in any one of claims 1-3, characterized in that, include: The base, which is a right-angled trapezoidal shape that is narrower at the top and wider at the bottom, is used to support the various unit components of the machining tool; The moving unit, located at the top of the base and connected to the base, is capable of moving the processing unit in the X, Y, and Z directions. The machining unit, which is connected to the moving unit, includes a tool magazine support, an automatic tool changer, a tool spindle, a B-axis rotary table, and an internal grinding head spindle, and can perform different machining processes on the workpiece through the linkage of several axes; The cradle, which adopts a trapezoidal groove structure, is located at the top of the Y-axis moving module. The bottom of the cradle is provided with a guide rail mounting seat, which has an adjustable locking device. The middle of the cradle is provided with a workpiece spindle for clamping the workpiece to be processed and cooling it. The mobile unit includes, The X-axis moving module is installed on the trapezoidal top of the base. The mounting surface near the trapezoidal inclined surface of the base is concave. A groove is provided on the concave side of the concave shape. The X-axis moving module is used to move the processing unit in the X direction. The X-axis moving module has a forward-protruding mounting foot on each of its lower left and right sides, and the mounting foot is set on the concave mounting seat of the base; The Y-axis moving module is installed on the trapezoidal inclined surface of the base and has a rectangular cavity inside. The Y-axis moving module is used to move the processing unit in the Y direction. The Z-axis moving module is vertically disposed in front of the concave side of the X-axis moving module and can slide on the X-axis moving module in the X direction for moving the processing unit in the Z-axis. The Z-axis moving module is slidably disposed in front of the X-axis moving module, and the Y-axis moving module is fixedly connected to the trapezoidal inclined surface of the base.

5. The multi-axis composite machining center according to claim 4, characterized in that, The X-axis moving module is provided with three X-axis linear guides in the same plane. The plane in which the X-axis linear guides are located is perpendicular to the mounting bottom surface of the X-axis moving module. The Z-axis moving module slides on the X-axis moving module through the X-axis linear guides. The Y-axis moving module has a recessed rectangular cavity inside. The rectangular cavity is surrounded by wall panels and has a bottom plate. The upper part of the rectangular cavity is open, and two Y-axis guide rails are provided at the top of the rectangular cavity. The Z-axis moving module is vertically equipped with four Z-axis linear guides. The processing unit moves in the Z-axis direction via the Z-axis linear guides. The Z-axis linear guides are equipped with Z1 slide saddles and Z2 slide saddles, which are driven by lead screws and can be independently controlled.

6. The multi-axis composite machining center according to claim 4, characterized in that, The automatic tool changer is disc-shaped and located on the upper side of the X-axis moving module. It is connected to the X-axis moving module through the tool magazine bracket and is used to accommodate several tools that can be mounted on the tool spindle. The B-axis turntable is connected to the Z1 slide saddle via a circular mounting seat. The B-axis turntable can rotate around the Y-axis, enabling precise positioning and locking at any angle. The tool spindle is mounted on the B-axis rotary table and connected to the Z1 slide saddle via the B-axis rotary table. The tool spindle can move in conjunction with the moving unit to perform axial feed and process the workpiece at different processes and angles. The spindle of the internal grinding head is mounted on the Z2 slide saddle. It can control the movement of the grinding wheel of the internal grinding head relative to the inner axis of the workpiece through axial feed, adjust it in the radial direction, change the contact position between the grinding wheel and the inner surface of the workpiece, and also change the contact angle of the grinding wheel by rotation and tilting.

7. The multi-axis composite machining center according to claim 5, characterized in that, The X-direction linear guide is divided into an X-direction first guide, an X-direction second guide, and an X-direction third guide from bottom to top. The distance between the X-direction first guide and the X-direction second guide is smaller than the distance between the X-direction second guide and the X-direction third guide. A lead screw mounting position is provided between the X-direction first guide and the X-direction second guide. The X-direction drive motor of the lead screw is on the same side as the automatic tool changer. The Y-axis guide rail is divided into a first Y-axis guide rail and a second Y-axis guide rail. The Y-axis lead screw is installed on the inner side of one of the Y-axis guide rails. The Y-axis drive motor of the Y-axis lead screw is installed in the middle and rear part of the base, located in the concave position of the U-shaped X-axis moving module. The Z-axis linear guide is divided into a Z1-axis first guide, a Z1-axis second guide, a Z2-axis first guide, and a Z2-axis second guide. A Z1-axis lead screw is installed between the Z1-axis first guide and the Z1-axis second guide, and a Z2-axis lead screw is installed between the Z2-axis first guide and the Z2-axis second guide. The Z-axis drive motors of the Z1-axis lead screw and the Z2-axis lead screw are installed on the top of the Z-axis moving module. The Z1 slide saddle is installed on the Z1-axis first guide and the Z1-axis second guide, and the Z2 slide saddle is installed on the Z2-axis first guide and the Z2-axis second guide.

8. The multi-axis composite machining center according to claim 7, characterized in that, The X-axis slide saddle is mounted on the X-axis linear guide rail, and a shim for adjusting the perpendicularity of the X-axis and Z-axis is provided on the side of the mounting position of the X-axis linear guide rail.

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