A self-centering vice-based milling and drilling tool and a drilling method thereof

Abstract

This invention relates to the field of milling and drilling technology, and particularly to a milling and drilling fixture and method based on a self-centering vise. The milling and drilling fixture includes a vertical bed, a drill bit assembly, a cooling assembly, a double rotary table assembly, a data acquisition module, a coaxiality error detection module, a hole position distribution detection module, and an offline spacing detection module. The method includes determining the two-dimensional directional deviation based on the drill bit reference feature position located by hole position image information; determining whether the coaxiality of the double-layer stepped hole is qualified based on the coaxiality error of the reference hole position; determining whether the centers of the circles on the double diagonal machining line are collinear and whether the perpendicularity of the double diagonal machining line is qualified based on the collinearity characterization parameter; determining whether the spacing of each double-layer stepped hole is qualified based on the hole opening qualification margin coefficient of the double-layer stepped hole, and adjusting the preset qualification threshold based on the non-qualification condition. This invention improves the machining accuracy of hole positioning, coaxiality, and hole position arrangement.

Description

Technical Field

[0001] This invention relates to the field of milling and drilling technology, and in particular to a milling and drilling fixture based on a self-centering vise and a drilling method thereof. Background Technology

[0002] CNC drilling and milling is one of the core technologies in the mechanical manufacturing field, widely used in industries with extremely high requirements for hole machining accuracy, such as aerospace, automotive manufacturing, electronic components, and medical devices. As the manufacturing industry develops towards precision and automation, the requirements for hole positioning accuracy, coaxiality, hole distribution regularity, and hole diameter consistency are constantly increasing. For precision hole systems on aerospace structural components, the coaxiality error often needs to be less than 0.008mm; for key components such as automotive engine blocks, the hole position error needs to be controlled at the micrometer level. However, the CNC drilling and milling field mainly relies on manual tool setting, manual measurement benchmarks, or offline programming for positioning. The resulting measurement errors and clamping deviations are difficult to eliminate. There is a lack of automatic verification methods for the deviation between the workpiece coordinate system and the machine tool coordinate system before machining. This leads to the initial piece positioning accuracy relying on operational experience. When the workpiece shape is complex or the clamping position is offset, traditional adjustment processes cannot quickly and accurately complete deviation identification and automatic compensation before machining, easily causing batch hole position deviations, affecting product quality and machining consistency.

[0003] Chinese Patent Application Publication No. CN121535234A discloses a vision-based five-axis drilling CNC machine tool and machining method, including a machine tool body, a CNC system, a contact probe, a vision system, and a calculation and control unit. The contact probe automatically collects the coordinates of at least three non-collinear reference features on the workpiece in the machine tool coordinate system. A coordinate system transformation algorithm automatically calculates the deviation between the workpiece coordinate system and the machine tool coordinate system. After establishing the workpiece coordinate system, the vision system moves to above each programmed hole position to capture actual marks. Image recognition extracts the actual hole center coordinates, which are compared with theoretical coordinates. Finally, by integrating probe data, vision images, CNC programs, and tolerance parameters, deviation calculation and machining decisions are made. This invention effectively solves the technical problems of human error and lack of pre-machining verification through an automated process integrating measurement, recognition, comparison, and decision-making.

[0004] The existing technology also has the following problems: For the coaxiality error of double-layer stepped holes during the processing, it usually relies on offline detection after processing. It is impossible to detect and compensate for the drill bit axis deviation in real time during the drilling process, which affects the smoothness of subsequent assembly; The regularity control of the array hole distribution is insufficient. After the benchmark positioning compensation, the middle hole and the corner hole may deviate from the theoretical collinear path due to the accumulation of errors, which will cause the included angle between the two diagonals to deviate from the perpendicularity. Summary of the Invention

[0005] To address this, the present invention provides a milling and drilling fixture and drilling method based on a self-centering vise, which overcomes the problems in the prior art where coaxiality detection and compensation are lacking, drill bit axis deviation cannot be detected and compensated in real time during drilling, the regularity of array hole distribution is insufficient, and after benchmark positioning compensation, the middle hole and corner hole deviate from the theoretical collinear path due to accumulated errors, resulting in the angle between the two diagonals deviating from the perpendicular.

[0006] To achieve the above objectives, in one aspect, the present invention provides a milling and drilling fixture based on a self-centering vise, comprising: Upright bed frame; The drill assembly includes a servo spindle motor disposed on the upper inner side of the vertical bed, a tool clamping component disposed at the bottom of the servo spindle motor for locking and fixing the tool, and a drill bit disposed inside the tool clamping component for milling. A dual rotary table assembly includes a rotary table disposed on the upper surface of the lower part of the vertical bed for providing rotary indexing motion, a mounting part disposed on the rotary table for providing linear guidance and mounting reference, and a clamping part disposed on the mounting part for realizing workpiece clamping. The deviation correction module is used to determine the two-dimensional directional deviation based on the drill bit reference feature position located by the hole position image information, and to adjust the drill bit position based on the comparison results of the two-dimensional directional deviation with the preset qualified threshold. The coaxiality error detection module determines whether the coaxiality of the double-step hole is qualified based on the coaxiality error of the reference hole position, and adjusts the axis angle of the drill bit. The hole position distribution detection module determines whether the centers of the projected circles on the double diagonal machining line are collinear and whether the perpendicularity of the double diagonal machining line is qualified based on the collinearity characterization parameter in order to adjust the drill bit trajectory. The offline spacing detection module is used to determine whether the spacing of each double-layer stepped hole is qualified based on the hole opening qualification margin coefficient, and adjust the preset qualification threshold based on the unqualified condition.

[0007] Furthermore, the two-dimensional directional deviation includes lateral deviation and longitudinal deviation; The deviation correction module determines that the drill bit positioning is unqualified based on the comparison result of the lateral deviation being greater than a preset qualified threshold or the longitudinal deviation being greater than a preset qualified threshold.

[0008] Furthermore, when the drill bit positioning is unqualified, the deviation correction module adjusts the drill bit's lateral coordinate in the opposite direction of the lateral deviation based on the lateral deviation. Adjust the drill bit's ordinate in the opposite direction of the longitudinal deviation.

[0009] Furthermore, the coaxiality error detection module determines that the coaxiality of the double-step hole is unqualified based on the comparison result that the coaxiality error of the reference hole position is greater than the preset coaxiality error, and adjusts the axis angle of the drill bit in the opposite direction of the deviation based on the deviation offset angle.

[0010] Furthermore, the hole position distribution detection module determines that the centers of the projected circles on the double diagonal machining lines are collinear based on the comparison results of whether the collinearity characterization parameter of the double diagonal machining lines is less than or equal to a preset collinearity error threshold.

[0011] Furthermore, under the condition that the centers of the projected circles on the double diagonal machining line are collinear, the hole position distribution detection module determines that the perpendicularity of the double diagonal machining line is unqualified based on the comparison result that the perpendicularity deviation of the double diagonal machining line is greater than the preset perpendicularity error threshold.

[0012] Furthermore, under the condition that the perpendicularity of the double diagonal machining line is not qualified, the hole position distribution detection module determines the transformed drill bit trajectory by multiplying the original coordinates of the hole to be adjusted with the rotation correction matrix.

[0013] Furthermore, the offline spacing detection module determines that the spacing of each double-layer stepped hole is unqualified based on the comparison result that the orifice qualification margin coefficient is less than 1.

[0014] Furthermore, when the spacing of the double-layer stepped hole is unqualified, the offline spacing detection module sets several threshold adjustment coefficients to adjust the preset qualified threshold based on the comparison result of the difference between 1 and the qualified margin coefficient of the hole opening and the preset margin difference.

[0015] On the other hand, the present invention also provides a drilling method based on a self-centering vise milling and drilling fixture, comprising: Based on the two-dimensional deviation between the reference feature position and the ideal reference position, the results of the comparison with the preset qualified threshold are used to determine whether the drill bit positioning is qualified, and the position of the drill bit is adjusted based on the unqualified conditions. In response to the drill bit positioning being qualified, the coaxiality of the double-step hole is determined based on the coaxiality error of the reference hole position, and the axis angle of the drill bit is adjusted based on the unqualified condition. In response to the coaxiality being qualified, based on the collinearity characterization parameters of the double diagonal machining connection, it is determined whether the projection centers of the double diagonal machining connection are collinear, and based on the perpendicularity deviation of the double diagonal machining connection, it is determined whether the perpendicularity of the double diagonal machining connection is qualified, and the drill trajectory is adjusted based on the perpendicularity failure condition. The spacing of each double-layer stepped hole is determined based on the orifice qualification margin coefficient, and the preset qualification threshold is adjusted based on the non-qualification condition.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention constructs a unified rectangular coordinate system based on the combination of an image acquisition device and a laser positioner, with the ideal reference position as the origin. Simultaneously, it achieves step-by-step detection and real-time correction from the coaxiality of three layers of a single hole, the collinearity and perpendicularity of X-shaped holes, to the full-domain accuracy of hole spacing on the entire plate. It tightens the preset qualified threshold to achieve root cause deviation management, provides compensation for workpieces in the same batch, and solves the problems of inaccurate positioning, easy coaxial deviation, disordered hole arrangement, and poor consistency of batch processing in traditional processing.

[0017] Furthermore, this invention establishes a dedicated coordinate system with an ideal reference position as the origin, enabling independent identification and equal-amplitude compensation of lateral and longitudinal deviations. This allows for rapid correction of the drill bit position, avoiding deviation accumulation and calculation delays. Simultaneously, by combining image filtering, edge detection, and least-squares circle fitting, the invention accurately extracts the center of the three-layer projection circle of the double-step hole. The coaxiality is determined by the maximum Euclidean distance and directly mapped to the axis angle compensation amount, avoiding the phenomenon of a qualified hole opening but a skewed hole bottom. This improves the drill bit positioning accuracy and the overall coaxial machining quality of the double-step hole.

[0018] Furthermore, this invention employs least squares linear fitting for the double diagonal machining lines, using the maximum perpendicular distance from the center of the projection circle to the fitted line as the collinearity characterization parameter. It combines slope tangent and arctangent calculations to accurately solve the actual included angle and quantify the perpendicularity deviation, distinguishing between normal minor process deviations and structural offsets. By using a rotation correction matrix, it unidirectionally fine-tunes the coordinates of the double-layer stepped holes to a vertical state, thereby improving the collinearity, perpendicularity, and distribution regularity of the ×-shaped hole positions.

[0019] Furthermore, this invention introduces a hole acceptance margin coefficient that integrates the local deviation of single hole spacing with the root mean square deviation of hole positions on the entire plate. This addresses the phenomenon where each adjacent hole spacing is individually acceptable, but there is an overall trend deviation. By tightening the preset acceptance threshold, the collinearity constraint standard of hole positions on the double diagonal machining line of subsequent workpieces is improved. This suppresses the spacing deviation caused by the double-layer stepped hole deviation from the source and is used for feedforward compensation of subsequent batch workpieces, thereby improving the overall hole spacing accuracy, machining acceptance rate, and machining consistency of workpieces in the same batch. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the milling and drilling fixture based on a self-centering vise according to an embodiment of the present invention; Figure 2 This is a bottom view of a milling and drilling fixture based on a self-centering vise according to an embodiment of the present invention; Figure 3 This is a partial structural schematic diagram of Embodiment A of the present invention; Figure 4 This is a partial structural schematic diagram of Embodiment B of the present invention; Figure 5This is a structural block diagram of a milling and drilling fixture based on a self-centering vise, according to an embodiment of the present invention. Figure 6 This is a flowchart of a drilling method based on a self-centering bench vise milling and drilling fixture according to an embodiment of the present invention; In the diagram: 1. Vertical bed, 2. Drill bit assembly, 21. Servo spindle motor, 22. Spindle body, 23. Tool clamping assembly, 24. Drill bit, 3. Cooling assembly, 31. Bamboo-joint tube body, 32. Locking adjustment component, 33. Conical nozzle, 4. Dual rotary table assembly, 41. Rotary table, 42. Mounting base, 43. Mounting base plate, 44. Clamping part, 45. Fixed side slide, 46. Movable side slide, 47. Adjusting screw, 48. Corrugated clamping tooth block, 5. Image acquisition unit, 6. Laser positioner. Detailed Implementation

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] The present invention will now be described in a clear and detailed manner with reference to the accompanying drawings.

[0026] Please see Figures 1-5 As shown, Figure 1 This is a schematic diagram of the milling and drilling fixture based on a self-centering vise according to an embodiment of the present invention; Figure 2This is a bottom view of a milling and drilling fixture based on a self-centering vise according to an embodiment of the present invention; Figure 3 This is a partial structural schematic diagram of Embodiment A of the present invention; Figure 4 This is a partial structural schematic diagram of Embodiment B of the present invention; Figure 5 This is a structural block diagram of a milling and drilling fixture based on a self-centering vise, according to an embodiment of the present invention.

[0027] This invention provides a milling and drilling fixture based on a self-centering vise, comprising: Vertical bed frame 1; The drill assembly 2 is disposed on the upper inner side of the vertical bed 1 for drilling and milling operations. It includes a servo spindle motor 21 for providing the rotational power required for drilling and milling, and a drill bit 24 disposed inside the tool clamping component 23 for milling. The tool clamping component includes a spindle body 22 disposed at the bottom of the servo spindle motor 21 to ensure runout accuracy during high-speed rotation, and a tool clamping component 23 disposed at the bottom of the spindle body 22 to cooperate with the spindle body 22 to lock and fix the tool. The cooling assembly 3 is located on the side of the drill assembly 2 and includes a freely bendable bamboo-shaped tube 31 for conveying coolant, a locking adjustment member 32 located near the fixed end of the bamboo-shaped tube 31 for locking the bending shape of the bamboo-shaped tube 31, and a conical nozzle 33 located at the end of the bamboo-shaped tube 31 for accurately spraying coolant into the cutting area. The dual rotary table assembly 4, disposed on the lower upper surface of the vertical bed 1, includes a rotary table 41 for providing rotary indexing motion, a mounting portion disposed on the upper surface of the rotary table 41 for providing linear guidance and mounting reference, and a clamping portion 44 disposed on the upper surface of the mounting base plate 43 for clamping the workpiece. The mounting part includes a mounting base 42 and a mounting base plate 43 disposed on the upper surface of the mounting base 42 for providing a mounting reference; The clamping part 44 includes a fixed side slide 45 and a pair of movable side slides 46, an adjusting screw 47 for moving the movable side slides 46, and a corrugated clamping tooth block 48 disposed on the upper surface of the movable side slides 46 to achieve stable clamping of the workpiece. The data acquisition module includes an image acquisition device 5 disposed on the side of the drill bit assembly 2 for real-time acquisition of hole position image information, and a laser positioner 6 disposed on the lower surface of the servo spindle motor 21 for positioning an ideal reference position. The deviation correction module is used to determine the lateral and longitudinal deviations between the reference feature position and the ideal reference position based on the hole position image information, and to determine whether the drill bit positioning is qualified based on the comparison results of the lateral and longitudinal deviations with the preset qualified thresholds, and to adjust the drill bit position based on the unqualified conditions. The coaxiality error detection module, in response to the drill bit positioning being qualified, determines whether the coaxiality of the double-step hole is qualified based on the coaxiality error of the reference hole position, and adjusts the axis angle of the drill bit 24 based on the unqualified condition. The hole position distribution detection module responds to the coaxiality qualification, determines whether the projection centers on the double diagonal machining lines are collinear based on the collinearity characterization parameters of the double diagonal machining lines, and determines whether the perpendicularity of the double diagonal machining lines is qualified based on the perpendicularity deviation of the double diagonal machining lines, and adjusts the drill bit trajectory based on the perpendicularity failure condition. The offline spacing detection module is used to determine whether the spacing of each double-layer stepped hole is qualified based on the hole opening qualification margin coefficient, and adjust the preset qualification threshold based on the unqualified condition.

[0028] Specifically, the image acquisition device 5 can be a high-definition industrial area scan camera, a high-speed industrial line scan camera, or an integrated image acquisition camera with supplementary lighting; no specific limitation is made.

[0029] Specifically, the laser locator 6 can be a point laser locator, an infrared laser positioning sensor, or a coaxial laser positioning transmitter, without any specific limitation.

[0030] Specifically, this invention achieves full-process precision control of drilling and milling through five core functional modules. The deviation correction module uses the laser positioner 6 to determine the lateral and longitudinal deviations between the reference feature position and the ideal reference position coordinates, judges and reverses the drill bit position to ensure accurate drill bit positioning. The coaxiality error detection module extracts the three-layer center of the double-layer stepped hole and calculates the maximum Euclidean distance as the coaxiality error. When the coaxiality error exceeds the tolerance, it calculates the angle adjustment amount according to the deviation and adjusts the drill bit axis angle to keep the double-layer stepped hole concentric. The hole position distribution detection module identifies and corrects the problem of non-collinear or non-perpendicular hole positions through straight line fitting and angle tangent calculation, so that the double diagonal machining connection line is restored to a regular distribution. The offline spacing detection module introduces the hole position qualification margin coefficient and stores the error mapping table for subsequent batch feedforward compensation of the same batch of workpieces.

[0031] Before the drilling operation begins in this embodiment, a reference feature position is calibrated at the first drilling point of the workpiece according to the preset drilling program. The reference feature position is compared with the ideal reference position calibrated by the laser positioner 6, and the lateral deviation and longitudinal deviation are calculated to determine whether the positioning accuracy of the drill bit 24 meets the standard. The reference feature position is an independent geometric feature point preset on the workpiece surface, which is not actually drilled and is only used as a positioning verification reference. It is a solid without a hole diameter. The ideal reference position is the first theoretical geometric coordinate point of drilling preset according to the workpiece design drawings and processing technology reference under the same station and coordinate reference system as the reference feature position.

[0032] A rectangular coordinate system is established with the ideal reference position as the origin. The reference feature position is marked in the rectangular coordinate system. The horizontal coordinate of the reference feature position is the horizontal deviation between the ideal reference position and the reference feature position. The vertical coordinate of the reference feature position is the vertical deviation between the ideal reference position and the reference feature position.

[0033] Specifically, the deviation correction module determines that the drill bit positioning is unqualified based on the comparison result of the lateral deviation being greater than a preset qualified threshold or the longitudinal deviation being greater than a preset qualified threshold. The deviation correction module determines that the drill bit positioning is qualified based on the comparison result that the lateral deviation is less than or equal to the preset qualified threshold and the longitudinal deviation is less than or equal to the preset qualified threshold.

[0034] Specifically, the preset qualified threshold is 0.02mm. Multiple drilling and milling machines of the same specifications were batch-collected under standard working conditions to obtain reference hole positioning image data. Workpiece material and drill bit specifications were standardized, and a total of 260 sets of valid sample data on hole positioning deviations were obtained. The results show that under normal and accurate positioning conditions, the lateral and longitudinal deviations between the reference feature position and the ideal reference position are concentrated in the range of [0.01mm, 0.03mm]. Furthermore, through multiple sets of comparative processing experiments, it was verified that when 0.02mm is used as the preset qualified threshold, the hole position deviation recognition accuracy can reach 97.2%, with both the false positive rate and the false negative rate being less than 1.8%. This approach can balance drilling positioning accuracy and equipment processing adaptability. Therefore, this scheme preferably uses 0.02mm as the preset qualified threshold.

[0035] Specifically, the laser locator 6 determines the lateral and longitudinal deviations between the reference feature position and the ideal reference position coordinates, independently judges the deviation of the borehole in the X and Y axis directions, avoids the problem of a single distance index masking a serious deviation in a certain direction after coordinate synthesis, and enhances the directionality of deviation identification.

[0036] Specifically, when the drill bit positioning is unqualified, the deviation correction module adjusts the horizontal coordinate of the drill bit 24 in the opposite direction of the horizontal deviation based on the horizontal deviation. The longitudinal coordinate of drill bit 24 is adjusted in the opposite direction of the longitudinal deviation.

[0037] It is understandable that the adjustment range is the horizontal or vertical coordinate value of the reference feature position, and the adjustment direction is the opposite of the horizontal or vertical deviation.

[0038] Specifically, the deviation correction module adjusts the horizontal and vertical coordinates of the drill bit 24 under the condition of unqualified drill bit positioning, so that the single compensation amount corresponds to the measured deviation in the same amplitude and direction. It can achieve one-time full correction of deviation without introducing other parameters, realize rapid response correction of offset, avoid deviation accumulation, reduce calculation delay, and ensure that the drill bit returns to the target position within the shortest control cycle. It significantly improves the response speed and determinism of positioning correction, and enhances the stability and consistency of the hole position correction process.

[0039] Specifically, under the condition that the drill bit is positioned correctly, the drilling operation is started. The processing sequence of the array of holes of the same workpiece to be processed follows the following principle: during the processing, continuous drilling of adjacent holes is avoided. In this embodiment, the holes are all coaxial double-layer stepped holes, which include a large diameter section and a small diameter section in sequence along the axial direction. The two hole walls are arranged coaxially to form a stepped double-layer structure. Taking a workpiece with 13 rows and 13 columns of arrayed holes as an example, the overall drilling process can be divided into three processing stages: the first processing stage is to drill holes with the reference feature position as the center to form the reference hole position; In the second processing stage, with the reference hole position as the center, drilling operations are completed for all holes within the X-shaped coverage area along the X-shaped processing path, forming a double diagonal processing line. The two single lines of the X-shape are the first diagonal processing line and the second diagonal processing line, respectively. In the third processing stage, the adjacent hole at any of the outermost corners of the array holes is selected as the first hole to be processed in this stage. Then, the adjacent holes at the other corners are processed in a counterclockwise or clockwise direction. After the processing of this layer of holes is completed, the inner adjacent holes of each corner are processed inward. The processing is carried out in a spiral manner from the outside to the inside until the drilling of all holes to be processed on the workpiece is completed. In this embodiment of the invention, the coordinate system is a rectangular coordinate system established with the ideal reference position as the origin.

[0040] Specifically, the coaxiality error detection module determines that the coaxiality of the double-layer stepped hole is qualified based on the comparison result that the coaxiality error of the reference hole position is less than or equal to the preset coaxiality error. The coaxiality error detection module determines that the coaxiality of the double-layer stepped hole is unqualified based on the comparison result that the coaxiality error of the reference hole position is greater than the preset coaxiality error.

[0041] Specifically, the coaxiality error is determined based on the centers of the first step circle, the second step circle, and the bottom circle of the double-layer stepped hole.

[0042] Specifically, the image acquisition device 5 vertically captures images of the opening along the axial direction of the double-step hole, acquiring hole position image information including the first step hole wall (large diameter section), the second step hole wall (small diameter section), and the hole bottom features. Grayscale processing, filtering, noise reduction, and contrast enhancement are then performed. Using edge detection algorithms such as the Canny operator, the closed contours corresponding to the first step hole wall, the second step hole wall, and the hole bottom features are located. Based on the least squares circle fitting algorithm, each selected closed contour is fitted with a circle, and each fitted circle is projected onto a rectangular coordinate system established with the ideal reference position as the origin, obtaining the corresponding first step circle, second step circle, and hole bottom circle. The center coordinates of each circle are then determined. This is existing technology and will not be elaborated further.

[0043] Specifically, the Euclidean distance between any two circle centers is calculated based on the coordinates of each circle center, and the maximum Euclidean distance is selected as the coaxiality error.

[0044] Specifically, the preset coaxiality error value is 0.05mm. By collecting data on the drilling and milling mechanism of this embodiment under standard machining conditions, for coaxial double-layer holes on the plate, the center coordinates of the first step circle, the second step circle, and the bottom circle of a single double-layer hole are detected respectively. The Euclidean distance between any two circles is calculated and the maximum distance is selected as the coaxiality error. A total of 300 sets of valid coaxiality error data are obtained. The results show that the coaxiality error of all qualified samples that meet the requirements of subsequent assembly and use is distributed within 0. The accuracy of double-layer hole coaxiality detection is 97.3%, with 98.7% of the errors occurring within 0.05mm. The error occurs most frequently around 0.05mm. When 0.05mm is used as the preset coaxiality error threshold, the accuracy of double-layer hole coaxiality detection reaches 97.3%, with a false alarm rate of less than 1.5% and a false negative rate of less than 1.2%. This can strictly control the coaxiality accuracy of double-layer holes and avoid problems such as assembly jamming and uneven force due to excessive coaxiality deviation. Therefore, this solution prefers 0.05mm as the preset coaxiality error threshold.

[0045] Specifically, by judging the coaxiality error of each hole, the false qualified phenomenon of hole openings being collinear but hole bottoms being skewed can be avoided, thus improving the smoothness of penetration.

[0046] Specifically, when the coaxiality is not up to standard, the coaxiality error detection module adjusts the axis angle of the drill bit 24 in the opposite direction of the deviation based on the deviation offset angle.

[0047] Specifically, the deviation offset angle is determined as follows: the axial depth of the double-step hole is used as the vertical right-angle side, and the coaxiality error is used as the horizontal right-angle side to form a right triangle. The arctangent value is calculated by using the arctangent function to calculate the ratio of the radial deviation to the axial depth. The coaxiality error of the linear distance is converted into the deviation offset angle corresponding to the drill bit axis. The adjustment range of the drill bit axis angle is the deviation offset angle, and the adjustment direction is the opposite direction of the deviation offset angle.

[0048] Specifically, the linear coaxiality error measurement value is directly mapped to the angle compensation amount of the drill bit axis. This ensures that the single angle adjustment amount corresponds to the offset angle corresponding to the measured coaxiality deviation with equal amplitude and opposite direction. The axis deviation can be fully corrected in one go without multiple trial corrections, significantly shortening the control cycle of angle compensation, avoiding the accumulation of errors caused by step-by-step adjustments, ensuring that the drill bit axis returns to the ideal coaxial state within the shortest control cycle, greatly improving the response speed and certainty of coaxiality correction, and enhancing the stability and consistency of coaxiality error correction during deep hole or stepped hole machining.

[0049] Specifically, the hole distribution detection module determines that the centers of the projected circles on the double diagonal machining lines are collinear based on the comparison results of the collinearity characterization parameters of the double diagonal machining lines being less than or equal to a preset collinearity error threshold. The hole distribution detection module determines that the projection centers of the two diagonal machining lines are not collinear based on the comparison results of the collinearity characterization parameters of the two diagonal machining lines being greater than the preset collinearity error threshold.

[0050] Specifically, the process of determining the collinearity characterization parameters is as follows: based on the projection of each double-layer stepped hole on the first diagonal machining line and the second diagonal machining line onto the center of the circle in the rectangular coordinate system, a first fitted line and a second fitted line are obtained. The maximum vertical distance from the projection center of each double-layer stepped hole on the first diagonal machining line to the first fitted line and the maximum vertical distance from the projection center of each double-layer stepped hole on the second diagonal machining line to the second fitted line are determined. The maximum vertical distances corresponding to the first diagonal machining line and the second diagonal machining line are determined as the collinearity characterization parameters of the corresponding diagonal machining lines. The first fitted line and the second fitted line are obtained by fitting using the least squares method.

[0051] Specifically, the preset collinearity error threshold was set to 0.04 mm. Eighty plates of the same specification were processed by the drilling and milling mechanism under coaxiality compliance conditions. Under standard processing conditions, for each plate with an X-shaped hole distribution, the coordinates of the projected center of the double-stepped holes on each straight line were extracted. After fitting the straight lines using the least squares method, the vertical distance from each projected center to the corresponding fitted straight line was calculated, resulting in 240 sets of valid vertical distance data. The results show that for all samples with qualified hole distribution that meet the subsequent overall drilling accuracy requirements, the projected center of the holes on each straight line... The vertical distances from the center to the fitted straight line are all distributed between 0.01mm and 0.04mm, with distances within 0.04mm accounting for 98.2%, and the frequency of occurrence around 0.04mm is the highest. When 0.04mm is used as the preset collinearity error threshold, the accuracy of hole position collinearity detection reaches 97.5%, the false alarm rate is less than 1.3%, and the false negative rate is less than 1.2%. It can strictly control the collinearity accuracy of hole positions on a single straight line and avoid problems such as disordered distribution of subsequent X-shaped holes and angle deviation caused by hole position offset. Therefore, this scheme preferably selects 0.04mm as the preset collinearity error threshold.

[0052] Specifically, the coaxiality of each double-layer stepped hole on the first and second diagonal machining lines is checked and projected onto the center of a circle in a rectangular coordinate system. The first and second fitted lines are obtained by fitting the lines using the least squares method. The maximum vertical distance from the projection center of each double-layer stepped hole on the double diagonal machining line to the corresponding fitted line is determined as the collinearity characterization parameter. This eliminates the need for complex coordinate conversion and detection steps, adapts to the real-time detection requirements of drilling and milling, and can quickly provide feedback on the collinearity detection results of the double diagonal machining lines without affecting the overall processing rhythm. It effectively distinguishes between normal minor deviations and unqualified offsets, avoids misjudgments caused by environmental interference and detection errors, ensures the consistency and reliability of the hole collinearity detection results on the double diagonal machining lines, reduces processing losses caused by missed or false detections, and strictly controls the collinearity accuracy of the double diagonal holes to avoid the problem of disordered distribution of subsequent X-shaped holes due to hole offset.

[0053] Specifically, under the condition that the projection centers of the two diagonal machining lines are collinear, the hole position distribution detection module determines that the perpendicularity of the two diagonal machining lines is qualified based on the comparison result that the perpendicularity deviation of the two diagonal machining lines is less than or equal to the preset perpendicularity error threshold. The hole distribution detection module determines that the perpendicularity of the double diagonal machining connection is unqualified based on the comparison result that the perpendicularity deviation of the double diagonal machining connection is greater than the preset perpendicularity error threshold.

[0054] Specifically, the method for calculating the perpendicularity deviation includes determining the tangent value of the double diagonal processing line based on the first slope of the first fitted line and the second slope of the second fitted line, converting the tangent value into the actual angle between the first fitted line and the second fitted line through the arctangent function, and determining the absolute value of the difference between the actual angle and the ideal perpendicular angle 90° as the perpendicularity deviation. The absolute value of the difference between the second slope and the first slope is the numerator of the tangent value, the sum of the product of the first slope and the second slope and 1 is the denominator of the tangent value, and the ratio of the numerator to the denominator of the tangent value is the tangent value.

[0055] Specifically, the preset perpendicularity error threshold was set to 0.5°. By collecting data from 90 identical plates processed by the drilling and milling mechanism under the condition of collinear hole positions, and under standard processing conditions, for each plate with two X-shaped hole lines, the projected center coordinates of each double-layered stepped hole on the first and second diagonal processing lines were extracted. The least squares method was used to fit the lines and determine their slopes. Then, the actual included angle and perpendicularity deviation of the two lines were calculated, resulting in 270 sets of effective perpendicularity deviation data. The results show that... For samples with qualified hole distribution that meet the requirements for subsequent assembly and use, the perpendicularity deviation of the two straight lines of the hole positions is distributed in the range of 0.1°-0.5°, with the deviation within 0.5° accounting for 98.5%. Through multiple sets of comparative tests, it was verified that when 0.5° is used as the preset perpendicularity error threshold, the accuracy of the perpendicularity detection of the angle between the two straight lines reaches 97.8%, and the false alarm rate is less than 1.2%. It can strictly control the perpendicularity accuracy of the two straight lines of the ×-shaped hole position, taking into account both detection efficiency and processing adaptability. Therefore, this scheme preferably uses 0.5° as the preset perpendicularity error threshold.

[0056] Specifically, by determining the tangent value through the slope of the fitted straight line and converting it to the actual angle using the arctangent function, the angle between the two diagonally connected machining lines is reflected. This controls the verticality requirements of the X-shaped hole position, ensuring that drilling in the entire area avoids affecting the performance of the workpiece due to verticality deviation. It effectively distinguishes between normal minor deviations and unqualified offsets, ensuring the consistency and reliability of verticality detection results, reducing machining losses caused by missed or false detections, and adapting to the real-time detection needs of drilling and milling.

[0057] Specifically, when the perpendicularity of the double diagonal machining line is not qualified, the hole position distribution detection module determines the transformed drill bit trajectory by multiplying the original coordinates of the hole to be adjusted with the rotation correction matrix.

[0058] Specifically, with the ideal reference position as the rotation center, the holes to be adjusted are all the double-layer stepped holes on the first diagonal machining line, while all the double-layer stepped holes on the second diagonal machining line remain unchanged.

[0059] Specifically, the rotation correction matrix has cosδ in the first row and first column, -sinδ in the first row and second column, sinδ in the second row and second column, and cosδ in the second row and second column. The rotation correction angle δ is calculated as the product of the negative value of the verticality deviation and the adjustment intensity coefficient.

[0060] Specifically, the adjustment strength coefficient was set to 0.95. By collecting data from 200 identical workpieces to be processed by the drilling and milling equipment, different perpendicularity deviation scenarios were simulated for the X-shaped hole layout of each workpiece. The adjustment effect under different strength coefficients was calculated, and a total of 800 sets of valid test data were obtained. The results showed that when the adjustment strength coefficient was set to 0.95, the adjusted perpendicularity deviation could be controlled within 0.3°, and there was no overcorrection during the adjustment process. It is suitable for the precise adjustment requirements of single hole and single straight line, with the fastest adjustment response speed, a detection accuracy rate of 97.2%, and a false alarm rate of less than 2.5%, which fully meets the processing accuracy requirements. Therefore, this solution preferably uses 0.95 as the adjustment strength coefficient.

[0061] Specifically, using the slopes of the two fitted straight lines on the double diagonal machining line acquired by image acquisition device 5, the tangent of the angle between the two straight lines is calculated and the actual angle is obtained by switching back and forth. The absolute value of the difference between the actual angle and the ideal vertical angle is used as the verticality deviation. This independently determines whether the angle between the two straight lines deviates from the vertical direction, avoiding the problem of a single distance index masking the angle shift in a certain direction. This significantly enhances the ability to identify the direction of the verticality deviation. The setting of the rotation correction matrix and the adjustment intensity coefficient provides a benchmark for adjusting the drill trajectory under the condition that the verticality of the angle between the two diagonal machining lines is unqualified. This ensures that one straight line remains fixed, while the other straight line is rotated to gradually approach the vertical in the direction of reducing the deviation. This ensures that the verticality deviation is accurately corrected within a controllable step size, avoiding new angle deviations caused by a single overcorrection.

[0062] Specifically, the offline spacing detection module determines that the spacing of each double-layer stepped hole is qualified based on the comparison result that the orifice qualification margin coefficient is greater than or equal to 1. The offline spacing detection module determines that the spacing of each double-layer stepped hole is unqualified based on the comparison result that the orifice qualification margin coefficient is less than 1.

[0063] Specifically, the orifice qualification margin coefficient is determined as follows: the ratio of the preset single-hole spacing allowable deviation to the actual single-hole spacing deviation of a single double-layer stepped hole is calculated, the minimum ratio is determined as the first ratio, and the ratio of the ideal hole position root mean square deviation to the overall hole position root mean square deviation is determined as the second ratio; the smaller value between the first ratio and the second ratio is selected, and the smaller value is determined as the orifice qualification margin coefficient. Specifically, the actual distance between the projection center of a single double-layer stepped hole and the projection centers of the four double-layer stepped holes in the cross-shaped adjacent direction is determined. The maximum distance among the actual distances is extracted, and the absolute value of the difference between the maximum distance and the ideal distance is determined as the actual single hole distance deviation.

[0064] Specifically, the actual spacing is calculated as follows: calculate the Euclidean distance between the projection center of a single double-layer stepped hole and the projection centers of the four adjacent double-layer stepped holes in the vertical direction, and take the maximum value among the four Euclidean distances as the actual spacing of the single double-layer stepped hole. The overall root mean square deviation of hole positions is calculated as follows: determine the deviation between the actual projected center coordinates and the ideal projected center coordinates of all double-stepped holes on the processing plate, determine the sum of the squares of all deviations, and the ratio of this sum to the total number of double-stepped holes. Take the square root of the ratio, and the result is the overall root mean square deviation of hole positions.

[0065] Specifically, the preset allowable deviation for single hole spacing is 0.03mm. By collecting data on the workpieces to be processed by the drilling and milling equipment, the actual distance between adjacent holes is measured, and the difference between the actual distance and the ideal distance is calculated. A total of 200 sets of valid deviation data are obtained. The results show that for all workpieces that are processed successfully and whose hole spacing meets the design requirements, the deviation of the distance between adjacent holes is concentrated between 0.01mm and 0.03mm, with the highest frequency occurring around 0.03mm. The single hole spacing deviation does not exceed 0.03mm. Through comparative experiments, it is verified that when the preset allowable deviation for single hole spacing is 0.03mm, the accuracy of hole spacing detection reaches 97.8%, and the false alarm rate is less than 1.8%. This can strictly control the accuracy of hole spacing and avoid affecting subsequent assembly and use due to excessive deviation. Therefore, this solution prefers 0.03mm as the preset allowable deviation for single hole spacing.

[0066] Specifically, the preset value for the ideal hole position root mean square deviation is 0.025mm. By collecting data from multiple batches of identical plates that have passed coaxiality, collinearity, and hole spacing tests using this drilling and milling mechanism, and under standard machining conditions, the overall root mean square deviation of the actual projected center of all double-layer stepped holes on the entire plate was statistically calculated to show that for qualified samples where all hole distribution and assembly accuracy meet design requirements, the overall root mean square deviation of the hole positions is distributed within the range of 0.015mm-0.025mm. 0.025mm is considered normal for qualified workpieces. When the upper limit critical value of the deviation fluctuation is set to 0.025mm as the preset standard value of the root mean square deviation of the ideal hole position, the overall accuracy of the hole position distribution detection of the whole board reaches more than 97%, and the misjudgment rate is less than 1.5%. It will not cause the workpieces with out-of-tolerance to be misjudged as qualified due to the excessively large threshold setting relaxing the overall hole position dispersion standard, nor will it cause the workpieces with normal process deviations to be misjudged as unqualified due to the excessively small threshold setting making the standard too strict. It can match the actual processing accuracy capability of the equipment and the overall hole position distribution requirements of the workpiece assembly. Therefore, this solution prefers 0.025mm as the preset standard value of the root mean square deviation of the ideal hole position.

[0067] Specifically, the ideal projection center coordinates are uniformly set based on the array hole size marked on the workpiece design drawing, the geometric arrangement of the double-layer stepped holes on the X-shaped double diagonal machining line, and the preset process benchmark. A rectangular coordinate system is established with the ideal benchmark position after positioning as the coordinate origin. The ideal projection center position of each double-layer stepped hole is marked one by one according to the standard row and column spacing and geometric layout constraints. This serves as a benchmark reference without machining errors and is used to compare with the actual projection center coordinates to solve the position deviation and calculate the root mean square deviation of the overall hole position.

[0068] Specifically, when the maximum adjacent hole spacing deviation does not exceed the ideal spacing and the global root mean square deviation does not exceed the ideal hole position root mean square deviation, the first ratio and the second ratio of the preset single hole spacing allowable deviation to the actual single hole spacing deviation, and the second ratio of the ideal hole position root mean square deviation to the overall hole position root mean square deviation are both not less than 1. The smaller value between the first ratio and the second ratio is determined as the hole opening qualification margin coefficient, so that the final margin coefficient can simultaneously reflect the weak link in the local hole spacing deviation and the overall position deviation, triggering the non-compliance judgment, avoiding one value being much greater than 1 from masking the fuzzy range of another value being slightly less than 1, and providing a more stringent and unambiguous single threshold criterion.

[0069] Specifically, when the spacing of the double-layer stepped hole is unqualified, the offline spacing detection module sets several threshold adjustment coefficients to adjust the preset qualified threshold based on the comparison result of the difference between 1 and the qualified margin coefficient of the hole opening and the preset margin difference.

[0070] Specifically, the offline spacing detection module determines to reduce the preset qualified threshold by a first threshold adjustment coefficient based on the comparison result that the margin difference is greater than or equal to the preset margin difference. The offline spacing detection module determines to reduce the preset qualified threshold by using a second threshold adjustment coefficient based on the comparison result that the margin difference is less than the preset margin difference.

[0071] Specifically, the preset margin difference is set to 0.1. In this embodiment of the invention, 150 workpieces of the same specification processed by the drilling and milling equipment under standard working conditions are collected, the margin difference of each workpiece is calculated, and the correspondence between the margin difference and the lateral deviation and the longitudinal deviation is statistically analyzed. The results show that when the lateral deviation and the longitudinal deviation are in the range of 0.02mm-0.03mm, the margin difference is mainly concentrated in the range of 0.05-0.10; when the positioning deviation exceeds 0.03mm, the margin difference is mostly greater than 0.10. Taking the preset margin difference as 0.10, the severity of the positioning deviation is clearly distinguished into medium deviation and severe deviation. The first threshold adjustment coefficient is 0.003. In this embodiment of the invention, 200 groups of data were simulated and divided into severe deviations. The effects of reducing the preset qualified threshold by 0.001, 0.003, and 0.005 were tested respectively. The results showed that when the first threshold adjustment coefficient was set to 0.003, the positioning qualification rate was increased by 32.4%, while the hole spacing failure rate decreased by 54.7%, resulting in the best overall effect. Therefore, 0.003 is the optimal first threshold adjustment coefficient. The second threshold adjustment coefficient is 0.001. In this embodiment of the invention, by comparing 150 groups of data divided into medium deviations, the effects of reducing the preset qualified threshold by 0.0005, 0.001, and 0.002 were tested respectively. The results show that when the second threshold adjustment coefficient is set to 0.001, the non-compliance rate of hole spacing can be reduced by 26.5% while the misjudgment rate is controlled within 1.8%, and fine-tuning can correct the error. Therefore, 0.001 is the optimal second threshold adjustment coefficient.

[0072] Specifically, when the preset acceptable threshold is too loose, the drill bit positioning is allowed to have a large lateral or longitudinal deviation during the processing. This deviation will accumulate hole by hole, eventually causing the actual distance between adjacent double-layer stepped holes to deviate from the design value, thus making the hole opening acceptable margin coefficient less than 1. Therefore, when the offline distance detection module determines that the hole distance between the double-layer stepped holes is unacceptable, it is inferred that insufficient hole positioning accuracy is the key root cause of this unacceptability. By tightening the preset acceptable threshold, the lateral and longitudinal positioning constraint standards of the remaining workpieces in the same batch or the next batch of workpieces when positioning the first hole are improved, thus suppressing the hole distance deviation between the double-layer stepped holes caused by the accumulation of positioning deviation from the source.

[0073] Please see Figure 6As shown, Figure 6 This is a flowchart of a drilling method based on a self-centering bench vise milling and drilling fixture according to an embodiment of the present invention.

[0074] The present invention provides a drilling method based on a self-centering vise milling and drilling fixture, comprising: Based on the two-dimensional deviation between the reference feature position and the ideal reference position, the results of the comparison with the preset qualified threshold are used to determine whether the drill bit positioning is qualified, and the position of the drill bit 24 is adjusted based on the unqualified condition. In response to the drill bit positioning being qualified, the coaxiality of the double-step hole is determined based on the coaxiality error of the reference hole position, and the axis angle of the drill bit 24 is adjusted based on the unqualified condition. In response to the coaxiality being qualified, based on the collinearity characterization parameters of the double diagonal machining connection, it is determined whether the projection centers of the double diagonal machining connection are collinear, and based on the perpendicularity deviation of the double diagonal machining connection, it is determined whether the perpendicularity of the double diagonal machining connection is qualified, and the trajectory of the drill bit 24 is adjusted based on the perpendicularity failure condition. The spacing of each double-layer stepped hole is determined based on the orifice qualification margin coefficient, and the preset qualification threshold is adjusted based on the non-qualification condition.

[0075] 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.

Claims

1. A self-centering jaw based milling and drilling tooling, characterized by, include: Upright bed frame; The drill assembly includes a servo spindle motor disposed on the upper inner side of the vertical bed, a tool clamping component disposed at the bottom of the servo spindle motor for locking and fixing the tool, and a drill bit disposed inside the tool clamping component for milling. A dual rotary table assembly includes a rotary table disposed on the upper surface of the lower part of the vertical bed for providing rotary indexing motion, a mounting part disposed on the rotary table for providing linear guidance and mounting reference, and a clamping part disposed on the mounting part for realizing workpiece clamping. The deviation correction module is used to determine the two-dimensional directional deviation based on the drill bit reference feature position located by the hole position image information, and to adjust the drill bit position based on the comparison results of the two-dimensional directional deviation with the preset qualified threshold. The coaxiality error detection module determines whether the coaxiality of the double-step hole is qualified based on the coaxiality error of the reference hole position, and adjusts the axis angle of the drill bit. The hole position distribution detection module determines whether the centers of the projected circles on the double diagonal machining line are collinear and whether the perpendicularity of the double diagonal machining line is qualified based on the collinearity characterization parameter in order to adjust the drill bit trajectory. The offline spacing detection module is used to determine whether the spacing of each double-layer stepped hole is qualified based on the hole opening qualification margin coefficient, and adjust the preset qualification threshold based on the unqualified condition.

2. The milling and drilling fixture based on a self-centering vise according to claim 1, characterized in that, The two-dimensional directional deviation includes lateral deviation and longitudinal deviation; The deviation correction module determines that the drill bit positioning is unqualified based on the comparison result of the lateral deviation being greater than a preset qualified threshold or the longitudinal deviation being greater than a preset qualified threshold.

3. The milling and drilling fixture based on a self-centering vise according to claim 2, characterized in that, When the drill bit positioning is unqualified, the deviation correction module adjusts the horizontal coordinate of the drill bit in the opposite direction of the horizontal deviation based on the horizontal deviation. Adjust the drill bit's ordinate in the opposite direction of the longitudinal deviation.

4. The milling and drilling fixture based on a self-centering vise according to claim 3, characterized in that, The coaxiality error detection module determines that the coaxiality of the double-step hole is unqualified based on the comparison result that the coaxiality error of the reference hole position is greater than the preset coaxiality error, and adjusts the axis angle of the drill bit in the opposite direction of the deviation based on the deviation offset angle.

5. The milling and drilling fixture based on a self-centering vise according to claim 4, characterized in that, The hole distribution detection module determines that the centers of the projected circles on the double diagonal machining lines are collinear based on the comparison results of the collinearity characterization parameters of the double diagonal machining lines being less than or equal to a preset collinearity error threshold.

6. The milling and drilling fixture based on a self-centering vise according to claim 5, characterized in that, Under the condition that the centers of the projected circles on the double diagonal machining line are collinear, the hole position distribution detection module determines that the perpendicularity of the double diagonal machining line is unqualified based on the comparison result that the perpendicularity deviation of the double diagonal machining line is greater than the preset perpendicularity error threshold.

7. The milling and drilling fixture based on a self-centering vise according to claim 6, characterized in that, When the perpendicularity of the double diagonal machining line is not qualified, the hole position distribution detection module determines the transformed drill bit trajectory by multiplying the original coordinates of the hole to be adjusted with the rotation correction matrix.

8. The milling and drilling fixture based on a self-centering vise according to claim 7, characterized in that, The offline spacing detection module determines that the spacing of each double-layer stepped hole is unqualified based on the comparison result that the orifice qualification margin coefficient is less than 1.

9. The milling and drilling fixture based on a self-centering vise according to claim 8, characterized in that, When the spacing of the double-layer stepped hole is unqualified, the offline spacing detection module sets several threshold adjustment coefficients to adjust the preset qualified threshold based on the comparison result of the difference between the margin difference of the qualified margin coefficient of the hole opening and the preset margin difference.

10. A drilling method applied to the milling and drilling fixture based on the self-centering vise as described in any one of claims 1-9, characterized in that, include: Based on the two-dimensional deviation between the reference feature position and the ideal reference position, the results of the comparison with the preset qualified threshold are used to determine whether the drill bit positioning is qualified, and the position of the drill bit is adjusted based on the unqualified conditions. In response to the drill bit positioning being qualified, the coaxiality of the double-step hole is determined based on the coaxiality error of the reference hole position, and the axis angle of the drill bit is adjusted based on the unqualified condition. In response to the coaxiality being qualified, based on the collinearity characterization parameters of the double diagonal machining connection, it is determined whether the projection centers of the double diagonal machining connection are collinear, and based on the perpendicularity deviation of the double diagonal machining connection, it is determined whether the perpendicularity of the double diagonal machining connection is qualified, and the drill trajectory is adjusted based on the perpendicularity failure condition. The spacing of each double-layer stepped hole is determined based on the orifice qualification margin coefficient, and the preset qualification threshold is adjusted based on the non-qualification condition.

Images