263 results about "Tool path" patented technology

The invention discloses a machining error-oriented hardware part size compensation method and platform, and relates to the technical field of industrial control, in particular to the technical field of hardware part machining. The method comprises the steps that based on a to-be-machined part, structural basic characteristics are obtained, and a three-dimensional size compensation map is drawn up with the elasticity modulus of a material as a constraint; matching each tool path target compensation amount sequence based on the map, and synchronously predicting a size deviation value; introducing an environmental interference factor, and inputting the pre-training model to generate a dynamic correction coefficient; and on the basis of the data, cutter compensation, the feeding rate and the rotating speed are dynamically adjusted through a self-adaptive strategy till the machining error is stabilized within the tolerance range. The technical problem that in traditional hardware part machining, due to the fact that a static compensation strategy is difficult to adapt to a dynamic machining environment, the machining size precision is unstable is solved, and the technical effects that self-adaptive high-precision size compensation based on the real-time machining state and multi-source interference sensing is achieved, and the part machining consistency and the percent of pass are improved are achieved.

The invention relates to the technical field of machine tool control, and provides a machine tool machining control method and system.The method comprises the steps that in the machine tool machining process, microenvironment parameters of a cutting area are obtained and monitored; obtaining a cutter type, a workpiece material attribute and a preset cutting parameter corresponding to the machine tool; based on the tool type, the workpiece material attributes and the preset cutting parameters, an initial judgment basis of the tool wear speed is established; according to the deviation between the microenvironment parameters and a preset standard value, the initial judgment basis is corrected, and the corrected tool wear speed is obtained; according to the actual tool abrasion loss, the rule for subsequently correcting the initial judgment basis is optimized; and based on the corrected tool wear speed, the tool remaining life is updated, and when tool wear reaches a preset threshold value, a compensation strategy of the cutting parameters or the tool path is decided and executed in combination with the value of the machined workpiece and the remaining machining task. The method has the effect of improving the prediction accuracy of the tool wear speed.

The invention relates to the technical field of precision manufacturing, and discloses a high-precision numerical control machine tool thermal error compensation method and system.The method comprises the steps that temperature data of key parts of a machine tool are collected in real time through a sensor array, and temperature distribution is generated through preprocessing; simulating a heat propagation path based on finite element analysis to obtain thermal deformation distribution; quantizing contribution values of multiple heat sources to cutter position offset by adopting a neural network model; when the contribution value exceeds a threshold value, activating a cooling system compensation mechanism to generate an offset correction amount; the correction is fused into a machine tool control system to optimize a tool path, and the thermal error model is dynamically updated based on the deviation between the actual machining position and the predicted deformation; and finally, a self-adaptive control strategy is generated in combination with the working condition parameters and the heat source contribution value, and accurate control over thermal errors is achieved through real-time feedback circulation. The method can solve the problem of low machine tool thermal error control precision in the prior art.

The invention provides a digital twinning five-axis machine tool contour error prediction method and system and electronic equipment, and belongs to the technical field of numerical control machine tool precision control and digital twinning. According to the method, servo axis data are collected in real time at a numerical control system end, electromechanical parameters are identified on line, comprehensive disturbance is estimated, and an autoregressive exogenous (ARX) model is updated accordingly; an interpolation instruction is generated in a digital twin body end mirror image numerical control system process, an updated model is utilized to predict a shaft position with deviation, a tool path is obtained through kinematics positive solution, and finally contour errors are calculated through geometric alignment. According to the digital twinning five-axis machine tool contour error prediction method and system and the electronic equipment, dynamic and high-precision prediction of the five-axis machine tool machining track contour error is achieved through the online identification and digital twinning technology, the limitation of a traditional static compensation method is overcome, and the precision of the digital twinning five-axis machine tool contour error prediction is improved. And a key basis is provided for prospective process optimization and precision control, and the machining precision and efficiency are effectively improved.

The invention relates to the technical field of ultra-precision intelligent manufacturing, in particular to an ultra-precision machining error compensation method based on multi-modal information fusion, a medium and equipment. The method comprises the following steps: acquiring three-dimensional shape data of a workpiece through an in-situ measurement device, synchronously acquiring temperature field and vibration data, constructing a multi-modal space-time tensor, inputting a physical information neural network to decouple a static geometric error, a time-varying thermal drift error and a dynamic vibration error, and generating a four-dimensional correction tool path to realize reverse compensation. According to the method, physical constraints are embedded through a PINN model, the problem of false thermal drift misjudgment in a traditional method is solved, experiments show that the RMS error of free-form surface machining is reduced to 5 nm or below, and the precision is improved by 70% or above; and meanwhile, error decoupling is endowed with physical interpretability, the small sample generalization ability is enhanced, and a technical basis is provided for process optimization.

The invention belongs to the technical field of numerical control machining, and discloses a numerical control machining tool path regulation and control method and system based on a dynamic coordinate system and overcut pre-judgment. The method aims at the problems that in complex curved surface grinding, due to static programming, tracks and poses are disjointed, and the overcut risk is difficult to control in time. The method comprises the steps that a dynamic coordinate system updated along with a tool edge line in real time is constructed, and design coordinates are mapped to the coordinate system; a sampling point is preset in the neighborhood of a grinding wheel theoretical contact point, and the theoretical distance and the actual distance between the sampling point and the axis of the grinding wheel are quantitatively calculated to achieve intelligent pre-judgment of the overcut risk before machining; and when it is judged that the risk exists, differentiated grinding wheel dynamic deflection angle correction is triggered in a grading mode according to the overcut occurrence position, and a perception pre-judgment correction closed loop is formed till the risk is eliminated. Dynamic coupling and self-adaptive regulation and control of the tool path and the real-time pose are achieved, and the machining precision, the consistency and the process reliability are remarkably improved.

Systems and methods utilize a CNC machine and include processor(s) that initiate display of a cutting program for cutting, via a cutting tool of the CNC machine, a block of material, where the cutting program sets a bounded region for cutting into the block of material. A selection of a first part from catalogued part(s) is received, and based thereon (i) G-code data of the first part into a current cutting cycle of the cutting program is imported, and (ii) a cutting tool path used to cut into the bounded region defined by the cutting program is displayed, where the cutting tool path outlining a shape of the first part such that cutting, via the CNC machine, along the cutting tool path forms the first part from the block of material. A positioning input is received that indicates a location for the cutting tool path relative the bounded region.

The invention discloses an intelligent control method of a numerical control dotting and ruling machine for mold machining, and particularly relates to the field of numerical control machining control. The method comprises the following steps: establishing a three-dimensional point cloud model containing surface microscopic curvature distribution and a local stress-strain relationship by acquiring a space geometric model and material physical parameters of a target mold workpiece; performing grid division on the point cloud model, extracting curvature features and local elastic modulus of each grid unit, and constructing a parameter matrix; in combination with the initial track of the preset tool path, modulating by adopting a self-adaptive control algorithm to generate a corrected path; in the machining process, a control vector is constructed based on the corrected path and the dotting depth and the scribing force which are fed back in real time, an execution mechanism is driven to conduct closed-loop control, and dynamic compensation of each dotting and scribing action is achieved; the method can effectively solve the problems of uneven dotting depth, lineation deformation and quick tool abrasion in the machining process of complex curved surfaces or high-strength materials, and the machining precision and stability are remarkably improved.

The invention provides a parameterized NURBS curve cutter radius compensation method and device, and relates to the technical field of numerical control machine tool machining control, and the method comprises the steps: calculating an offset direction for each original control point of an original NURBS curve, and carrying out the offset of the original control points through combining with a cutter compensation radius, and obtaining offset control points; performing position optimization on the offset control point; if the maximum error value between the offset NURBS curve constructed after position optimization and the ideal offset curve is greater than an error threshold value, adding a new original control point for the original NURBS curve in an error overrun area; after an original control point is added, the steps of control point offset, optimization, error calculation and judgment are repeatedly executed till the maximum error value between the obtained offset NURBS curve and the ideal offset curve is smaller than or equal to an error threshold value, and a final target control point is obtained; and generating a target NURBS curve based on the target control point, and performing smoothing processing on a trajectory self-intersection point and a breakpoint on the target NURBS curve to obtain a final tool path.

The invention relates to a dynamic lag compensation method for inclined hole machining of a base of a water jet cutting machine. The dynamic lag compensation method comprises the following steps that S1, machining parameters are obtained; s2, establishing a dynamic lag vector model; s3, based on the target axis vector of the inclined hole, establishing an asymmetric taper prediction model; s4, coupling the dynamic lag vector model and the asymmetric taper prediction model to generate a comprehensive compensation model; s5, real-time reverse compensation is conducted on a preset inclined hole cutting theoretical tool path; s6, the high-pressure abrasive water jet device is controlled to conduct inclined hole machining on the cutting machine base according to the execution path; and S7, in the cutting process, water jet pressure, abrasive flow and nozzle abrasion state parameters are built in real time. The method has the following advantages that accurate compensation of the dynamic hysteresis effect and effective suppression of the asymmetric taper are achieved, the hole axis and position precision is remarkably improved, and the high-quality hole wall shape is obtained.

The invention relates to the field of numerical control post-processing, and particularly discloses a five-axis series-parallel processing machine tool tool path post-processing method, which comprises the following steps: establishing a target test piece CAD model, importing a CAM software planning path, and generating an original tool location file containing a tool nose position and a tool axis direction vector; c4 continuous pH splines are inserted between corners and adjacent small line segments for fairing, and control polygon side length constraints are set; local synchronization is firstly carried out, and then a seven-time B spline is used for replacing a straight line segment to carry out global synchronization; key point speed limiting is conducted, feeding speed constraint is obtained in combination with multiple constraints, and the speed is planned through a mixed S-shaped curve; and S6, judging the position of an interpolation point, and selecting a corresponding mode for calculation. According to the technical scheme, the problems that fairing is sensitive, errors are difficult to control, pH splines are only C3 continuous, and parameters are not synchronous are solved, track continuity is improved, vibration and tracking errors are reduced, and machining precision and efficiency are improved.

The invention provides a wooden door three-dimensional model parameterization design and numerical control code generation method and system, and relates to the technical field of woodworking numerical control machining and computer vision. A multispectral imaging technology is adopted at a raw material feeding station to obtain a wood board surface multiband image, and a high-definition wood characteristic spectrum is generated through algorithm processing; establishing a mapping rule base of the atlas and numerical control parameters in combination with historical data; the map and the three-dimensional embossment model are superposed, and a tool path and cutting parameters are adaptively adjusted according to texture features to avoid defects and optimize along grains; and finally, numerical control codes matched with wood characteristics are generated, the rotating speed of the main shaft is adjusted according to the hardness, a numerical control machine tool is driven to complete high-precision wooden door machining, and precise numerical control machining based on wood surface characteristic intelligent recognition and self-adaptive adjustment can be achieved.

The invention belongs to the technical field of mechanical automation control, and particularly relates to a vibration suppression method and system for a five-axis linkage CNC machining center, and the method comprises the following steps: S1, carrying out the system identification of a target machine tool, and obtaining the frequency response characteristics of the target machine tool; s2, virtual cutting simulation is conducted based on the workpiece model and the machining program, and cutting force distribution is obtained; s3, predicting a tremor risk area in the machining process in combination with the frequency response characteristics and the cutting force distribution; s4, optimizing a tool path and a tool posture according to a prediction result so as to avoid tremor; s5, calculating and setting an optimal speed planning parameter under the non-tremor constraint based on the optimized path and the dynamic characteristics of the machine tool; and S6, performing trial processing, collecting actual data, and correcting simulation model parameters to improve subsequent prediction precision. According to the method, the machining program is optimized, cutting simulation is carried out on the machining program, the cutting force distribution condition in the machining process is obtained, tremor prediction is carried out in combination with the workpiece model, and the unreasonable tool posture is optimized.

The invention discloses a numerical control grinding machine machining precision control method and system, a medium and a product and relates to the field of numerical control machining. According to the method, a digital geometric model of a workpiece to be machined is obtained, and a preset machining tool path is generated; curvature gradient analysis is carried out on the digital geometric model along the preset machining tool path, and a local mutation area is obtained; generating a prediction compensation value based on the curvature and the curvature change rate of each processing point on the preset processing tool path and the relative position of each processing point and the local sudden change area; in the machining process, the machining deviation between the actual machining contour of the current machining point and the digital geometric model is obtained, and feedback correction is generated based on the machining deviation; and performing weighted fusion on the feedback correction amount corresponding to the current processing point and the predicted compensation value to generate a composite correction instruction, generating final process parameters based on the composite correction instruction, and controlling the numerical control grinding machine to execute the final process parameters. According to the technical scheme, the workpiece machining precision is improved.

The invention discloses a circumferential contour prediction method based on cutting force and deformation field space-time correlation, and relates to the field of aerospace, and the method comprises the following steps: 1, carrying out the spatial discretization of a circumferential contour region of a target workpiece; step 2, establishing a lightweight structure stiffness matrix; 3, constructing an elastic mechanism model and solving delta-F mapping; 4, introducing the time sequence correlation of the cutting load into the elastic mechanism model; step 5, constructing a Boolean relationship between the tool path and the workpiece envelope; step 6, fusing actual measurement process signals, and performing state correction; step 7, iterating the elastic model again by using the corrected load; and step 8, reconstructing full-field deformation based on spatial correlation. According to the method, online prediction of the station-level circumferential deformation field is achieved, the method can be used in the multi-procedure machining process, deformation in-situ compensation of the procedure is achieved, a clamping positioning strategy of the next procedure is output, and the manufacturing quality and the production efficiency are improved.

The utility model discloses a quick workpiece clamping and positioning structure of a numerical control machine tool, which belongs to the technical field of machine tool clamping tools, and comprises a base, the top of the base is fixedly connected with a machining box, the top of the inner wall of the machining box is provided with a machining cutter, and the bottom of the inner wall of the machining box is fixedly connected with an adjusting assembly. The problems that an existing quick workpiece clamping and positioning structure of the numerical control machine tool cannot adjust the position of a workpiece, in the actual machining process, due to the fact that an effective adjusting structure is lacked, after an operator fixes the workpiece, subtle deviation exists in the initial placement position, follow-up adjustment cannot be carried out, and machining efficiency is poor are solved. The problems that a tool path is not matched with the actual position of a workpiece due to the fact that the tool path is not matched with the actual position of the workpiece, a machined product is unqualified due to size out-of-tolerance, form and location tolerance and the like, the defective rate is increased, the production quality and efficiency of the product are seriously affected, and the practicability of the device is reduced are solved.

The invention discloses a shape error correction method for free-form surface machining, which comprises the following steps of: analyzing the path characteristics of an original cutter through a linearization error theory, establishing a slow cutter servo turning cutter path simulation model, and describing the cutting path of the cutter by adopting an Archimedes spiral. And on the basis, cutter radius compensation is carried out, cutter contact data after compensation are obtained, and the accuracy of a cutting track is ensured. Then, obtaining point clouds of the free-form surface to be processed, and obtaining source point clouds and target point clouds respectively; in order to realize reliable matching between the source point cloud and the target point cloud, point cloud coarse registration is used for coarse registration, and then point cloud fine registration is used for fine registration. And finally, calculating a shape error through a least square method, and applying the shape error to correction so as to obtain a processed free-form surface type.

The application relates to the technical field of motion planning, and discloses a corner fairing method of an asymmetric Airthoid-arc, which comprises the following steps: constructing a tool path fairing curve which is sequentially connected by a first Airthoid curve, an arc and a second Airthoid curve, and is used for fairing a corner formed by adjacent straight line segments; preliminarily setting a first transition length and a second transition length according to the lengths of the line segments on the two sides of the corner; solving the first and second tangent angles according to geometric constraints, tangential continuity, curvature continuity constraints and position continuity constraints; if there is a solution, analytically calculating a current approximate error; and finally analytically calculating the curvature extreme value and the arc length of the fairing curve. The asymmetric curve structure is adopted, the corner space is fully excavated, the curvature extreme value is small, the arc length can be analytically expressed, and the profile error is controllable, so that the numerical control machining efficiency is improved.

The invention belongs to the field of aero-engine and gas turbine machining, and discloses a blade margin plate and adapter numerical control machining tool path generation method and a related device, and the method comprises the steps: building a projection part model of a blade; establishing a reference plane at a preset distance from the blade inner edge plate, generating an intersection curve, offsetting to obtain an offset curve, and constructing a driving curved surface through regular extension; the radius of the milling cutter is not larger than that of the switching fillet; and on the basis of the projection model, variable contour milling is conducted through the driving curved surface, and an integrated numerical control machining tool path of the margin plate and switching is generated. According to the method, the machining cutter connecting position is transferred to the blade body molded surface area from the sensitive transfer fillet, and the root molded surface thinning out-of-tolerance caused by polishing is prevented. And a standard cutter is adopted to process a qualified transfer fillet through cutter path control, so that the cutter customization cost is reduced. The finally generated tool path lines are uniform, transition is continuous, a smooth switching structure can be directly machined, dependence on polishing is remarkably reduced, and the machining quality and the percent of pass are improved.

The invention relates to the technical field of numerical control machining, and discloses an automatic optimization method and system for a feeding and retracting tool path. Comprising the following steps: dividing an arc feeding and retracting action area into a convex side action area of a cutter on a cutter central trajectory, a concave side action area of the cutter on the cutter central trajectory, and an action area of a cutter feeding starting point or a retracting ending point according to the cutter central trajectory; detecting whether interference or tool stepping risks exist in the machining process or not in real time, if yes, selecting different path optimization logics according to the current tool action area, setting different combinations of performing increasing or reducing processing on the arc radius of the tool center trajectory and performing increasing or reducing processing on the central angle, and traversing; and if the optimization of the cutter feeding path fails, turning to lower the cutter, and if the optimization of the cutter retracting path fails, turning to lift the cutter. The tool feeding and retracting path can be dynamically adjusted, and the scientificity of tool feeding and retracting path planning and the machining efficiency are improved.

The invention discloses a self-adaptive variable-diameter spiral groove numerical control machining method and device based on wood curvature perception, and belongs to the technical field of wood spiral groove machining. The method comprises the following steps that S1, wood feeding and positioning are conducted, square timber to be machined is fixed through a self-adaptive clamp, and it is ensured that the axis of the square timber is aligned with the machining standard; s2, real-time data collection is conducted, specifically, the front face, the back face and the two side faces of the batten are scanned through multiple sets of laser displacement sensors, the curvature and moisture content data of the wood are collected in a high-precision mode through the multiple sets of laser displacement sensors, and a customized tool path matched with irregular deformation of the wood is generated in combination with a least square method curvature fitting algorithm; and meanwhile, a cutting pressure dynamic compensation mechanism is matched, the cutting pressure is stabilized within a reasonable range, heat expansion and cold contraction deformation of the groove profile is avoided through composite cooling shaping after machining, finally, the groove profile machining precision reaches + / -0.05 mm, the problems that traditional fixed parameter machining is poor in adaptability and low in size consistency are thoroughly solved, and the follow-up assembly difficulty is greatly reduced.

Provided are a display device, a computer program, and a storage medium that make it possible to increase visibility of a tool path. This display device comprises: an oscillation condition setting unit that sets oscillation conditions for oscillation cutting in which a workpiece and a tool are oscillated relative to each other; a tool path information generation unit that generates tool path information related to a tool path on the basis of the oscillation conditions; a determination unit that determines an actual cut portion and an air cut portion on the tool path on the basis of the tool path information; and a display control unit that controls a display unit to display thereon the tool path in which the actual cut portion and the air cut portion on the tool path are displayed in different manners.

The invention provides a five-axis rough machining path planning method based on a volume neural field. The five-axis rough machining path planning method comprises the following steps: S10, constructing a body region and outputting the neural field; s20, carrying out layering and path orthogonality and density constraint; s30, performing continuous and periodic smoothing processing on the cutter shaft field; s40, calculating collision safety and a minimum gap constraint; s50, the cutting volume is subjected to stabilizing treatment; s60, calculating total loss and determining a training process; and S70, tool path generation and post-processing are carried out. According to the scheme, the hierarchical field psi, the path field phi and the cutter shaft angle fields (A and C) are learned in the machining volume through the neural network, geometric orthogonality, cutter shaft smoothing / amplitude limiting, collision safety and removal stability are restrained in a unified mode through a micro-loss function, and therefore efficient, smooth and safe automatic rough machining path generation is achieved in complex structures such as a deep cavity and an impeller. The rough machining effect is good.

The invention relates to a method for realizing machining element guide treatment in plate rotating and turning machining, which comprises the following steps that three directions and two edge distances are defined for each machining element, the three directions comprise a machining surface, a reference surface and a direction surface, and the two edge distances comprise a longitudinal edge distance and a transverse edge distance; in the plate rotating or turning process, direction changing is conducted on the machining face, the reference face and the direction face according to a rotating algorithm; and determining the relative position of the processing element on the plate according to the transformed direction surface and the corresponding distance. By the adoption of the method and device for achieving machining element guide processing through rotating and turning plate machining of the plate, the processor and the readable storage medium of the processor, under the condition that shape information of the elements is not changed, the plate is rotated, quadrant switching is conducted, data consistency is guaranteed, error transformation caused by data change is reduced, and the machining efficiency is improved. The rotation algorithm performance is greatly optimized, and logic processing for obtaining the machining tool path according to the element information is simplified.

The invention provides a hollow cavity window type numerical control machining method. The hollow cavity window type numerical control machining method comprises the steps that 1, a machining window and a machining tool 8 of each station are determined; 2, by combining part machining window position characteristics, multi-window cutter axis vector space cross simulation is conducted through CAM software, and a track cross point 7 needing to achieve the purpose that a cutter path completely covers a to-be-machined face of a side plate or a bottom plate of a cavity is generated; calculating the shortest overhanging amount of a rough machining cutter and the shortest overhanging amount of a finish machining cutter which meet the requirements of the multi-window cross swing angle machining inner cavity according to the swing angle of the eight tool path tracks of the machining cutter and the height of the cavity of the part through limiting conditions; step 3, combining machine tool equipment performance, cutting parameters, a machining tool 8 in each stage and a swing angle, arranging a tool path track, and carrying out total element simulation verification; 4, rough machining of the first station is completed; 5, rough machining of a second station is completed; 6, finishing the finish machining of the first station; and 7, finish machining of the second station is completed.

The invention belongs to the related technical field of aero-engine manufacturing and precision repair, and discloses a blade repair path follow-up compensation method and device based on non-rigid matching, and the method comprises the steps: S1, reconstructing a machining error reference point cloud curved surface based on a scanning data point set and a repair region design model; s2, performing unified modeling on the static deviation of the machining error of the to-be-compensated blade to obtain an error transfer model, and simplifying the corresponding nonlinear comprehensive machining error into a calculation equation of linear pose deviation of a local workpiece coordinate system; s3, establishing a tangent contact approximation cost function based on non-rigid matching so as to register and approach a target curved surface under the constraint of retaining tool path features, and meanwhile, solving a calculation equation by adopting a least square method so as to obtain a linear pose deviation of a local workpiece coordinate system, solving to obtain a pose deviation of each tangent contact coordinate system so as to obtain a linear pose deviation of each tangent contact coordinate system; and furthermore, each cutting contact and each cutter location point are updated, and the shape follow-up compensation of the blade is realized. The compensation precision is improved.

The invention provides a machining path planning method and system based on artificial intelligence, and the method comprises the steps: firstly, generating a plurality of groups of spiral tool path trajectories through employing a finite element method in combination with an interpolation algorithm, and constructing a training data set; secondly, building a generative adversarial network composed of a generator and a discriminator, and training to obtain a spiral machining path generation network capable of generating a spiral machining path meeting the requirements of a machining area in a self-adaptive manner; then, an open source CNC speed planning module is used as a reinforcement learning environment, a machining path generation network and a value network are used as intelligent agents, and under the constraint of the maximum speed, acceleration and step, the generation network is optimized through iterative training, so that the aim of the shortest machining time is achieved; and finally, outputting the optimal path to CNC equipment to execute machining. According to the method, the path generation adaptability and the constraint adaptability are improved, the machining time is shortened compared with a traditional method, and the cavity machining efficiency and the intelligent level are remarkably improved.

The application discloses a numerical control machine tool machining program automatic generation method and system, and the method steps comprise the following: obtaining the image of a target part machining drawing and performing pretreatment; performing image recognition on the pretreated drawing image, recognizing geometric figures and dimension marking information; performing semantic analysis on the text information in the pretreated drawing image, obtaining machining process and parameter information; generating machining program code according to the image recognition result and the semantic analysis result, first generating a preliminary tool path according to each geometric figure and dimension marking information, then matching corresponding initial cutting parameters according to the machining process and adjusting the initial cutting parameters, optimizing the preliminary tool path by using the adjusted cutting parameters, and finally filling program instructions by using the optimized tool path and the adjusted cutting parameters. The application can process various machine tool machining drawings, automatically generate machining program code, and significantly improve the efficiency, precision and flexibility of the machining program.

The invention discloses an accurate positioning machining device for a valve flange face, and belongs to the field of valve flange face machining. The device comprises a bottom plate, the upper surface of the bottom plate is connected with a supporting plate through supporting columns in a supporting mode, and the middle of the supporting plate is provided with an open hole allowing the neck of a flange to penetrate through; at least three first pressing mechanisms are arranged on the peripheral side of the upper surface of the supporting plate, and first pressing plates of the first pressing mechanisms abut against the outer edge side of a flange body of the flange; and a second pressing plate of the second pressing mechanism abuts against the inner edge side of the flange body of the flange. The first pressing mechanism and the second pressing mechanism alternately clamp the outer edge and the inner edge of the flange in a bidirectional mode, one of the first pressing mechanism and the second pressing mechanism is selected to fix the flange during machining, then the inner side machining space and the outer side machining space of the flange are unlocked, the problems that a traditional clamp shields a tool path, and machining dead angles are generated are thoroughly solved, and machining efficiency is improved. And the multi-process requirements of cutting, drilling, polishing, paint spraying and the like are met.