Five-axis five-linkage milling head machining method with high negative pressure dust removal

Abstract

The application discloses a kind of high negative pressure dust removal five-axis five linkage milling head processing methods, belong to numerical control processing and dust removal control field.Processing program and tool, workpiece, dust removal execution piece and machine tool protection area data are obtained, cutting section, tool shaft posture switching section and milling head rotation instruction are identified;According to the update current workpiece occupied area of interpolation sequence, determine available position set, divide target cutting section and determine reachable position set and actual working position;When posture switches, according to the movement occupied area of dust removal execution piece with milling head rotation and preset safety gap, keep current position or move to preset posture switching avoidance position;After being in position and running, cutting is executed by negative pressure dust removal device, position deviation and running state are monitored during cutting, and cutting is stopped and tool is withdrawn when abnormal;After all target cutting sections are completed, delay stop and reset, so that dust removal position, suction passage and running state are coordinated with processing process.

Description

Technical Field

[0001] This invention relates to the fields of CNC milling and industrial dust removal technology, specifically to a five-axis, five-linkage milling head machining method with high negative pressure dust removal. Background Technology

[0002] Five-axis, five-linkage CNC machining uses the coordinated motion of linear and rotary axes to continuously change the spatial position and orientation of the cutting tool relative to the workpiece, making it suitable for milling composite material components, complex curved surface components, and other workpieces. During machining, the cutting tool rotates at high speed and comes into contact with the workpiece material, and the generated dust and fine chips are easily diffused into the surrounding area of ​​the machining zone by the cutting airflow.

[0003] To reduce dust dispersion, existing machining equipment typically includes a dust collection hood, dust inlet, and dust collection piping near the spindle or milling head. This allows the dust collection components to move with the spindle or milling head, utilizing the negative pressure generated by the dust collection equipment to collect dust near the cutting tool. While this method shortens the distance between the dust inlet and the cutting area, the dust collection structure still needs to adapt to the rotational motion of the milling head, changes in tool length, and variations in workpiece surface shape.

[0004] For example, Chinese patent CN224374272U discloses a five-axis oscillating head with an internally integrated spindle-driven dust collection pipe. It features a dust collection channel within a fork-shaped bracket, forming a dust collection path through a dust collection disc, a second dust collection disc, and a dust collection port. A ring-shaped bellows cover driven by a servo electric cylinder is mounted on the spindle box. This design reduces the rotation radius of the oscillating head assembly and minimizes the possibility of interference between the external dust collection pipe and the tooling or workpiece by integrating the dust collection pipe inside the oscillating head.

[0005] The above-mentioned solution mainly improves the dust removal conditions of the five-axis oscillating head by improving the dust collection channel layout and the mechanical extension of the dust collection hood. Its annular bellows hood can be extended and retracted according to the tool length. However, during five-axis five-linkage machining, the milling head posture, tool position, and workpiece surface orientation may change continuously with the machining trajectory. Adjusting the dust collection components solely based on the overall movement of the milling head or the tool length is still insufficient to ensure that the dust collection area continuously corresponds to the actual cutting position.

[0006] Especially when switching between different machining program segments, when the milling head swings at a large angle, when the tool is close to the workpiece edge, or when performing tool change positioning actions, the position and working state of the dust collection component need to be adapted to the current machining state. Otherwise, problems may arise such as the dust suction port deviating from the cutting area, insufficient dust collection range, or the dust collection component being too close to the workpiece and fixture. Therefore, how to coordinate the position and dust collection state of the dust collection component with the five-axis five-linkage machining process to balance near-source dust collection, continuous machining, and interference avoidance remains a technical problem that needs to be solved. Summary of the Invention

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions.

[0008] This invention provides a five-axis, five-linkage milling head machining method with high negative pressure dust removal. The milling head is mounted on a slide, and a dust removal main pipe is installed inside the slide. The milling head is equipped with a dust removal rotary table, a dust removal pipe, a servo electric cylinder, and a dust removal actuator driven by the servo electric cylinder and equipped with a dust suction port.

[0009] Acquire five-axis five-linkage machining programs, tool parameters, workpiece geometry data, dust removal actuator geometry data, and machine tool protection area data; identify cutting machining segments, tool axis posture switching segments, and milling head rotation commands.

[0010] Based on the tool axis posture, machining position, and the aforementioned parameters and data at the interpolation positions of each cutting machining segment, a set of usable positions is formed, consisting of positions where the gap between the dust removal actuator and the current workpiece's occupied area and the machine tool protection area is not less than a preset safety gap, and the minimum distance from the dust inlet boundary to the cutting area is within a preset dust removal distance range. If any set of usable positions is empty, the corresponding cutting machining segment is prohibited from execution. Otherwise, consecutive interpolation positions whose intersection remains non-empty are divided into the same target cutting segment, and the intersection of the common usable position set and the preset maximum stroke-limited stroke range is taken as the reachable position set. If the reachable position set is empty, the corresponding target cutting segment is prohibited from execution.

[0011] When the reachable location set is not empty, the actual working position is determined from it and the dust removal actuator is in place. The negative pressure dust removal device is started or kept running, forming a suction passage from the dust inlet through the dust removal pipe, dust removal rotary table and dust removal main pipe to the negative pressure dust removal device.

[0012] During the target cutting section, the suction passage is kept open by the dust removal rotary table during the rotation of the milling head;

[0013] Within the tool axis posture switching segment, the tool retracts, and the area occupied by the dust removal actuator as the milling head rotates is determined. It is then determined whether the gap between the dust removal actuator and the current workpiece area and the machine tool protection area before the posture switching is not less than the preset safety gap. If so, the current position is maintained and the milling head is rotated. Otherwise, the actuator is moved to the preset posture switching avoidance position, and the milling head is rotated again after the condition is met. Before executing the next target cutting segment after rotation, the actual working position is determined based on the reachable position set of the next target cutting segment, and the dust removal actuator is adjusted or kept in place.

[0014] Further, identifying the cutting process segment and the tool axis posture switching segment includes:

[0015] Extract the machining motion program segments from the five-axis five-linkage machining program, and exclude program segments containing tool change instructions and corresponding tool change positioning program segments;

[0016] The remaining machining motion program segment where the spindle is at the cutting speed and the tool moves along the machining trajectory according to the cutting feed command is defined as the cutting machining segment;

[0017] The remaining machining motion program segments associated with adjacent cutting segments, including stopping the cutting feed, controlling the tool to exit the cutting area, and executing the milling head rotation command, are defined as the tool axis posture switching segments.

[0018] Furthermore, the tool parameters include tool geometry parameters and tool length compensation values, and the workpiece geometry data includes initial workpiece geometry data; the current workpiece occupied area, available position set, target cutting segment, reachable position set, and target working position are determined, including:

[0019] The initial workpiece occupied area is determined based on the initial workpiece geometry data, and the initial workpiece occupied area is used as the current workpiece occupied area before machining at the starting interpolation position. According to the execution order of the interpolation positions, the tool sweep area between the current interpolation position and the next interpolation position is determined based on the tool parameters. The overlapping area between the tool sweep area and the current workpiece occupied area is determined as the material removal area. The material removal area is subtracted from the current workpiece occupied area to obtain the current workpiece occupied area before machining at the next interpolation position.

[0020] The cutting area is determined based on the tool parameters, tool axis posture, machining position, and the current workpiece area. The machine tool protection area is determined based on the machine tool protection area data. Along the servo electric cylinder drive direction, the available positions are formed by the gap between the dust removal actuator and the current workpiece area and the machine tool protection area that is not less than the preset safety gap, and the minimum distance from the dust inlet boundary to the cutting area that is within the preset dust removal distance range.

[0021] Starting from the initial interpolation position, sequentially calculate the intersection of the available position sets; when adding the next interpolation position to make the intersection empty, take the previous interpolation position as the end point of the current target cutting segment and the next interpolation position as the start point of the next target cutting segment;

[0022] The intersection of the common available positions of each target cutting section and the stroke range is taken as the reachable position set; the direction in which the dust suction port is close to the cutting area is taken as the extension direction. When the reachable position set is not empty, the position that is the foremost along the extension direction is determined as the target working position.

[0023] Furthermore, when the set of available positions for any interpolation position is empty, position unavailable information is generated, and the cutting segment containing that interpolation position is prohibited from execution;

[0024] When the intersection of the common available position set of the target cutting segment and the travel range is empty, dust removal actuator position over-limit information is generated, and the execution of the corresponding target cutting segment is prohibited.

[0025] Further, determining whether the preset safety clearance is satisfied between the moving area and the current workpiece area and the machine tool protection area includes:

[0026] Based on the current tool axis posture, the next tool axis posture, the milling head rotation command, the geometric data of the dust removal actuator, and the current position of the dust removal actuator, determine the motion area occupied by the dust removal actuator when it transitions from the current tool axis posture to the next tool axis posture;

[0027] Obtain the current workpiece occupied area before the attitude switching begins, and determine the two minimum distances between the motion occupied area and the current workpiece occupied area and the machine tool protection area, respectively;

[0028] When the moving area overlaps with the current workpiece area or the machine tool protection area, or when the minimum distance in any one of these conditions is less than the preset safety gap, it is determined that the preset safety gap is not met.

[0029] When there is no overlap and both minimum distances are not less than the preset safety gap, the preset safety gap is determined to be satisfied.

[0030] Furthermore, when the movement occupancy area determined based on the current position of the dust removal actuator does not meet the preset safety clearance, the servo electric cylinder is controlled to move the dust removal actuator to the preset attitude switching avoidance position;

[0031] Based on the preset posture switching avoidance position, the area occupied by the dust removal actuator during the milling head rotation process is redefined;

[0032] When the newly determined motion occupancy area meets the preset safety clearance with the current workpiece occupancy area and the machine tool protection area respectively, the milling head rotation command is executed; when either is not met, a posture switching avoidance failure message is generated and the execution of the milling head rotation command is prohibited.

[0033] After the milling head completes its rotation, the dust removal actuator is moved to the corresponding target working position according to the set of reachable positions for the next target cutting segment, or the current position is maintained when the current position belongs to the set of reachable positions, and the position after moving or maintaining is determined as the actual working position.

[0034] Furthermore, when the movement occupancy area determined based on the current position of the dust removal actuator satisfies the preset safety clearance, the dust removal actuator is kept in its current position and the milling head is rotated;

[0035] After the milling head has rotated, it is determined whether the current position of the dust removal actuator belongs to the reachable position set of the next target cutting segment, and the absolute position difference between the current position and the target working position corresponding to the next target cutting segment along the driving direction of the servo electric cylinder is determined.

[0036] When the current position belongs to the set of reachable positions and the absolute position difference is not greater than the preset position adjustment tolerance, the current position is determined as the actual working position of the next target cutting segment and remains unchanged.

[0037] When the current position does not belong to the set of reachable positions, or when the absolute position difference is greater than the preset position adjustment tolerance, the dust removal actuator is moved to the target working position corresponding to the next target cutting segment, and the target working position is determined as the actual working position.

[0038] Furthermore, maintaining the suction passage connected by the dust removal rotary table during the milling head rotation includes:

[0039] When the five-axis five-linkage milling head performs the milling head rotation motion, the dust removal main pipe is kept fixed relative to the slide, and the dust removal pipe rotates with the five-axis five-linkage milling head;

[0040] The dust removal rotary table maintains a sealed connection between the dust removal duct and the main dust removal pipe as they rotate relative to each other.

[0041] The dust generated in the cutting area is sequentially transported to the negative pressure dust removal device through the dust suction port, dust removal pipe, dust removal rotary table and dust removal main pipe.

[0042] Furthermore, when the five-axis five-linkage machining program includes a tool change command, the tool change segment is identified based on the tool change command and its associated tool change positioning command, and excluded from the cutting machining segment and the tool axis posture switching segment, and executed within the tool change segment:

[0043] Stop the cutting feed and control the tool to exit the cutting area along a preset retraction path;

[0044] The dust removal actuator is moved to a preset tool change avoidance position, and the tool change is performed after reaching the preset tool change avoidance position;

[0045] After the tool change is completed, the tool geometry parameters and tool length compensation value of the replaced tool are obtained, and the cutting area, available position set, target cutting segment, reachable position set and target working position of the subsequent cutting machining segment are re-determined based on the replaced tool parameters.

[0046] Before the tool enters the cutting area corresponding to the next target cutting segment, the dust removal actuator is moved from the preset tool change avoidance position to the target working position corresponding to the target cutting segment, and the target working position is determined as the actual working position.

[0047] Furthermore, before executing each target cutting segment, the position status signal of the servo electric cylinder and the operating status signal of the negative pressure dust removal device are acquired. Cutting feed is allowed only when the position status signal indicates that the dust removal actuator is in the corresponding actual working position and the operating status signal indicates that the negative pressure dust removal device is in operation.

[0048] During the execution of the target cutting segment, the current position of the servo electric cylinder and the running status signal are acquired, and the absolute position deviation between the current position and the corresponding actual working position along the driving direction of the servo electric cylinder is determined.

[0049] When the absolute position deviation exceeds the preset positioning deviation threshold, or when the negative pressure dust removal device stops operating, the cutting feed is stopped and the tool is controlled to exit the cutting area along the preset retraction path;

[0050] After all target cutting sections are completed, the negative pressure dust removal device is kept running for a preset delay time, then the negative pressure dust removal device is stopped, and the dust removal actuator is moved to a preset reset position.

[0051] Compared with the closest prior art, the present invention does not merely make the dust collection structure follow the milling head mechanically, but rather coordinates the dust collection position, posture switching avoidance, and negative pressure operation state with the five-axis five-linkage machining process, which has the following beneficial effects:

[0052] (1) The current workpiece occupied area is updated step by step according to the material removal process, and the available position set of each interpolation position is determined in combination with the machine tool protection area, the preset safety clearance and the preset dust removal distance range; the target cutting section is divided by the intersection of the sets and the reachable position set is determined, so that a suitable dust removal position can be maintained in the same target cutting section, while avoiding the dust removal actuator from exceeding the limit or entering an unsafe position.

[0053] (2) The safety of attitude switching is judged based on the area occupied by the dust removal actuator as the milling head rotates. If the current position does not meet the requirements, it is moved to the preset attitude switching avoidance position and re-verified so that the avoidance judgment covers the milling head rotation process and connects to the actual working position of the next target cutting section after rotation.

[0054] (3) The position status signal and the running status signal are used as the preconditions for cutting. The position deviation and negative pressure running status are continuously monitored during the cutting process. If there is an abnormality, the cutting is stopped and the tool is retracted. The machine is only stopped and reset after a delay after all the target cutting segments are completed, thereby reducing the dust emission during the cutting start and stop and continuous processing stages. Attached Figure Description

[0055] Figure 1 This is an overall flowchart of the five-axis, five-linkage milling head machining method with high negative pressure dust removal of the present invention;

[0056] Figure 2 This is a flowchart illustrating how the current workpiece occupies its area, the target cutting segment, and the actual working position in this invention.

[0057] Figure 3 This is a flowchart illustrating the actual working position of the tool axis posture switching and avoidance and the determination of the next target cutting segment in this invention.

[0058] Figure 4 This is a flowchart illustrating the control of the target cutting segment based on the position and running state according to the present invention.

[0059] Figure 5 This is a schematic diagram of the structure of the five-axis, five-linkage milling head with high negative pressure dust removal of the present invention. Detailed Implementation

[0060] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The following specific embodiments are used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention.

[0061] like Figure 5 As shown in the figure, a five-axis five-linkage milling head and its main dust removal structure are illustrated. The five-axis five-linkage machining equipment used in this embodiment includes a ram and a five-axis five-linkage milling head mounted on the ram. A dust removal main pipe is installed inside the ram, and the five-axis five-linkage milling head is equipped with a dust removal rotary table, a dust removal pipe, a servo electric cylinder, and a dust removal actuator. The servo electric cylinder drives the dust removal actuator with a suction port to move along its driving direction. Figure 5 The label "dust removal pipe inside the slide block" indicates the main dust removal pipe installed inside the slide block.

[0062] The suction port is connected to the negative pressure dust removal device via a dust removal pipe, a dust removal rotary table, and a dust removal main pipe, forming a suction passage from the suction port to the negative pressure dust removal device. The dust removal rotary table is located between the dust removal pipe and the dust removal main pipe.

[0063] When the five-axis five-linkage milling head performs the milling head rotation motion, the dust removal main pipe is fixed relative to the slide block, and the dust removal pipe rotates with the five-axis five-linkage milling head. The dust removal rotary table maintains a sealed connection between the dust removal pipe and the dust removal main pipe when they rotate relative to each other, thereby maintaining the connection of the suction passage during the milling head rotation process.

[0064] The servo electric cylinder can drive the dust removal actuator to move within a preset maximum stroke to the actual working position, a preset attitude switching avoidance position, a preset tool change avoidance position, or a preset reset position. In one specific embodiment, the preset maximum stroke of the dust removal actuator along the servo electric cylinder driving direction is 100 mm. This value is a specific stroke parameter used in this embodiment and does not constitute a limitation on the preset maximum stroke.

[0065] When the negative pressure dust removal device is in operation, a negative pressure suction effect is created at the dust inlet through the suction passage, causing the dust generated in the cutting area to be transported sequentially through the dust inlet, dust removal pipe, dust removal rotary table, and dust removal main pipe to the negative pressure dust removal device. The operating parameters of the negative pressure dust removal device can be preset according to the workpiece material, dust inlet size, suction passage length, and dust state generated during processing.

[0066] The preset safety clearance, preset dust removal distance range, preset position adjustment tolerance, preset positioning deviation threshold, and preset delay time are determined before machining. The preset safety clearance is used to compensate for machine tool positioning errors, geometric data conversion errors, and spatial position changes caused by machining vibrations. The preset dust removal distance range includes a lower limit and an upper limit. The lower limit is used to prevent the dust suction port from getting too close to the cutting area, and the upper limit is used to ensure that the dust suction port has an effective collection capacity for cutting dust. The preset position adjustment tolerance is used to determine whether the dust removal actuator needs to be readjusted after the milling head rotates. The preset positioning deviation threshold is used for positioning determination before cutting and for determining abnormal positioning during cutting. Both are preset.

[0067] The high negative pressure working state referred to in this embodiment refers to the working state in which the negative pressure dust removal device can form a stable airflow towards the inside of the suction passage at the dust inlet, and transport the cutting dust along the suction passage to the negative pressure dust removal device. The specific operating parameters are determined according to the workpiece material, the size of the dust inlet, the length of the suction passage, and the dust transport status during the trial run.

[0068] This implementation first identifies the cutting segment, tool axis posture switching segment, and tool change segment from the five-axis five-linkage machining program; then, it updates the current workpiece occupied area according to the material removal process, determines the available position set for each interpolation position, and divides the target cutting segment based on the intersection of the sets; before the target cutting segment is executed, the actual working position is determined; during tool axis posture switching, the motion occupied area formed by the dust removal actuator as the milling head rotates is verified; after tool change, the tool parameters and subsequent position results are updated; during the cutting process, the position deviation of the dust removal actuator and the operating status of the negative pressure dust removal device are continuously monitored.

[0069] like Figure 1 As shown, this embodiment includes the following steps.

[0070] Step 10: Obtain the processing program and related data and identify each processing segment.

[0071] Acquire the five-axis, five-linkage machining program, tool parameters, workpiece geometry data, dust removal actuator geometry data, and machine tool protection zone data. Tool parameters include tool geometry parameters and tool length compensation values, and workpiece geometry data includes initial workpiece geometry data.

[0072] The five-axis, five-linkage machining program is read from the CNC system's execution program. Based on the commands for each linear axis and rotary axis, the machining position and tool axis posture corresponding to each interpolation position are determined. The tool geometry parameters are represented by the tool geometry envelope in the tool coordinate system, and the tool length compensation value is used to determine the actual spatial position of the effective cutting part of the tool relative to the milling head reference position.

[0073] The initial workpiece geometry data is represented by the workpiece's three-dimensional solid data before machining. Based on the workpiece clamping position and the transformation relationship between the workpiece coordinate system and the machine tool coordinate system, the initial workpiece geometry data is transformed to the machine tool coordinate system. The dust removal actuator geometry data includes the external geometric envelope of the dust removal actuator, the dust inlet boundary, and the installation relationship between the dust removal actuator and the servo electric cylinder drive direction. The machine tool protection zone data represents the machine tool space area where the dust removal actuator is pre-restricted from entering.

[0074] The cutting tool, workpiece, dust removal actuator, dust inlet boundary, and machine tool protection area are all represented using the same machine tool coordinate system. Subsequent spatial overlap determination, minimum distance calculation, material removal area deduction, and motion-occupied area merging are all performed within this machine tool coordinate system.

[0075] Extract the machining motion program segment from the five-axis five-linkage machining program, identify the tool change segment based on the tool change command and its associated tool change positioning command, and exclude the tool change segment from the cutting machining segment and the tool axis posture switching segment.

[0076] In the machining motion program segment excluding the tool change segment, the segment where the spindle is at the cutting speed and the tool moves along the machining trajectory according to the cutting feed command is defined as the cutting machining segment. The cutting machining segment includes interpolation positions arranged sequentially according to the machining trajectory, and each interpolation position has a corresponding machining position and tool axis posture.

[0077] The machining motion program segment associated with the adjacent cutting machining segment, which includes stopping the cutting feed, controlling the tool to exit the cutting area, and executing the milling head rotation command, is identified as the tool axis posture switching segment, and the milling head rotation command is identified from each segment.

[0078] If the current segment to be executed is the cutting machining segment, proceed to step 20; if the current segment to be executed is the tool axis posture switching segment, proceed to step 30; if the current segment to be executed is the tool changing segment, execute the tool changing process in step 60.

[0079] Step 20: Determine the current workpiece occupied area, target cutting section, reachable position set, and actual working position.

[0080] like Figure 2 As shown, the initial workpiece occupied area is determined based on the initial workpiece geometry data before machining begins, and this initial workpiece occupied area is used as the current workpiece occupied area before machining begins at the starting interpolation position. The initial workpiece occupied area is represented by a three-dimensional solid in the machine tool coordinate system.

[0081] Following the execution order of interpolation positions in the cutting process segment, the interpolation intervals between adjacent interpolation positions are processed sequentially. For the current interpolation interval, the geometric envelope of the effective cutting portion of the tool is determined based on the tool geometry parameters and tool length compensation value. Then, based on the current interpolation position, the next interpolation position, and the tool axis posture change between them, the geometric envelope is transformed into the spatial positions of each tool within the interpolation interval. The space occupied by the effective cutting portion of the tool during continuous movement within this interpolation interval is merged to obtain the corresponding tool sweep area.

[0082] A solid intersection operation is performed between the tool sweep area and the current workpiece occupied area before machining in the interpolation interval. The overlapping area is the material removal area that the tool can actually remove in the interpolation interval, and this material removal area is determined as the corresponding cutting area. Then, the material removal area is subtracted from the current workpiece occupied area to obtain the current workpiece occupied area before machining in the next interpolation interval. This method is used to update interval by interval, so that the current workpiece occupied area used at any interpolation position corresponds to the workpiece space that has not been removed before the actual execution of that interpolation position.

[0083] The position of the dust removal actuator is represented by an axial position value along the drive direction of the servo electric cylinder, and the direction in which the dust suction port is close to the cutting area is taken as the extension direction. For an axial position to be determined, based on the installation relationship between the dust removal actuator, the servo electric cylinder, and the milling head, the outer geometric envelope of the dust removal actuator and the dust suction port inlet boundary are transformed to the machine tool coordinates corresponding to that axial position.

[0084] The minimum spatial distances between the outer geometric envelope of the dust removal actuator and the area occupied by the current workpiece, the outer geometric envelope of the dust removal actuator and the machine tool protection area, and the minimum spatial distance between the dust inlet boundary and the cutting area are determined separately. When the outer geometric envelope of the dust removal actuator overlaps with the area occupied by the current workpiece or the machine tool protection area, the corresponding gap is determined to be a non-compliance with the preset safety gap.

[0085] When the minimum spatial distances between the dust removal actuator and the current workpiece's occupied area, and the machine tool's protected area, are both not less than the preset safety clearance, and the minimum spatial distance between the dust inlet boundary and the cutting area is within the preset dust removal distance range, this axial position is determined as the available position of the current interpolation position. All axial positions that meet the above conditions form the set of available positions for this interpolation position; continuous available axial positions can be recorded as position intervals, and multiple discontinuous position intervals are retained separately.

[0086] When the available position set for any interpolation position is empty, it indicates that the dust extraction port cannot be within the preset dust removal distance range while satisfying the safety clearance. Position unavailable information is generated, and the cutting process segment containing that interpolation position is prohibited.

[0087] When the available position sets for each interpolation position are not empty, the intersection operation is performed starting from the initial interpolation position of the cutting segment. First, the available position set of the initial interpolation position is determined as the current intersection. Then, the available position sets of the next interpolation position are sequentially interpolated with the current intersection. If the intersection result is not empty, it is updated as the new current intersection, and subsequent interpolation positions are added. When the intersection result becomes empty for the first time after adding the next interpolation position, the previous interpolation position is determined as the end point of the current target cutting segment, and the next interpolation position is determined as the start point of the next target cutting segment. The current intersection is then re-established using the available position set of the next interpolation position. This process continues until all target cutting segments within the cutting segment are divided.

[0088] The current intersection retained when each target cutting segment is divided constitutes the set of common usable positions for that target cutting segment. Any position in the set of common usable positions simultaneously satisfies the safety clearance requirements and preset dust removal distance requirements of each interpolation position within the target cutting segment. Therefore, the dust removal actuator does not need to move repeatedly with each interpolation position during the execution of the target cutting segment.

[0089] The axial position range that the servo electric cylinder can reach is determined as a stroke range limited by a preset maximum stroke. The common available positions of the target cutting segment are intersected with this stroke range to obtain the reachable position set. If the intersection result is empty, a dust removal actuator position exceedance information is generated, and the execution of the corresponding target cutting segment is prohibited.

[0090] When the reachable position set is not empty, the foremost axial position along the extension direction is determined as the target working position. When the reachable position set includes multiple discontinuous position intervals, the foremost position along the extension direction in each interval is selected for comparison, and the overall foremost position is determined as the target working position. For the first target cutting segment or the next target cutting segment redefined after tool change, the dust removal actuator is moved to the target working position, and the target working position is determined as the actual working position. The actual working position after the milling head rotates is determined according to step 30.

[0091] Establish a correspondence between the start and end interpolation positions, common available position set, reachable position set, target working position and actual working position of each target cutting segment, so that subsequent control can read the corresponding position results according to the current target cutting segment.

[0092] Step 30: Perform tool axis posture switching to avoid obstacles and determine the actual working position of the next target cutting segment.

[0093] like Figure 3 As shown, during the tool axis posture switching segment, the cutting feed is first stopped and the tool is controlled to exit the cutting area. The current tool axis posture, the next tool axis posture, and the rotation sequence corresponding to the milling head rotation command are read, and the current position and geometric data of the dust removal actuator are read.

[0094] Using the axial position of the dust removal actuator at the start of the attitude change as a reference, and based on the rotation path defined by the milling head rotation command, the intermediate attitudes traversed by the milling head as it transitions from the current tool axis attitude to the next tool axis attitude are determined. For each intermediate attitude, based on the installation relationship between the dust removal actuator and the milling head, the external geometric envelope of the dust removal actuator is transformed from milling head coordinates to machine coordinates. Then, the space occupied by the dust removal actuator in each intermediate attitude and the space traversed by continuous rotation between adjacent intermediate attitudes are merged to obtain the motion-occupied area formed by the dust removal actuator as the milling head rotates. This motion-occupied area covers the entire rotation process, not just the rotation start attitude and rotation end attitude.

[0095] Obtain the current workpiece occupied area from the last update before the attitude change begins, and keep this current workpiece occupied area unchanged during the current attitude change judgment process. Determine the minimum spatial distance between the moving occupied area and the current workpiece occupied area, and the minimum spatial distance between the moving occupied area and the machine tool protection area.

[0096] When the area occupied by the movement overlaps with the area occupied by the current workpiece or the machine tool protection area, or when any of the minimum spatial distances is less than the preset safety gap, the current position is determined to not meet the posture switching requirements; when there is no overlap and both minimum spatial distances are not less than the preset safety gap, the current position is determined to meet the posture switching requirements.

[0097] When the current position meets the attitude switching requirements, the dust removal actuator remains in its current position while the milling head rotates. After rotation, the current axial position of the dust removal actuator is read, and it is determined whether this position belongs to the reachable position set of the next target cutting segment. The absolute position difference between this position and the corresponding target working position of the next target cutting segment is then determined. If the current position belongs to the reachable position set and the absolute position difference is not greater than the preset position adjustment tolerance, the current position is determined as the actual working position of the next target cutting segment; otherwise, the dust removal actuator is moved to the target working position, and the target working position is determined as the actual working position.

[0098] When the current position does not meet the attitude switching requirements, the dust removal actuator will be moved to a preset attitude switching avoidance position. The preset attitude switching avoidance position is a fixed axial position that is predetermined and written into the control parameters within a preset maximum stroke during the equipment commissioning phase. When switching attitudes, the avoidance position will not be reselected from multiple candidate positions.

[0099] After the dust removal actuator reaches the preset posture switching and avoidance position, this position is used as the new axial position. The movement area is redefined according to the same milling head rotation path as described above, and the minimum spatial distance between it and the current workpiece area and the machine tool protection area is recalculated. If the preset safety clearance is met, the milling head rotation command is executed; if it is not met, a posture switching and avoidance failure message is generated and the execution of the milling head rotation command is prohibited.

[0100] After the milling head rotates to the preset posture to avoid the obstacle, it is determined whether the position belongs to the set of reachable positions for the next target cutting segment. If it does, the position is designated as the actual working position and remains unchanged; otherwise, the dust removal actuator is moved to the target working position of the next target cutting segment, and the moved position is designated as the actual working position.

[0101] Step 40: Adjust the dust removal actuator and form or maintain the suction passage.

[0102] Read the actual working position corresponding to the current target cutting segment. When the current position of the dust removal actuator is inconsistent with the actual working position, control the servo electric cylinder to move the dust removal actuator to the actual working position; when the current position has been determined as the actual working position, keep the position of the dust removal actuator unchanged.

[0103] Based on the current position feedback of the servo electric cylinder, it is determined whether the dust removal actuator has reached the actual working position, and a position status signal is generated. The position status signal indicates that the dust removal actuator is at the actual working position corresponding to the current target cutting section.

[0104] The current position feedback value and the actual working position of the servo electric cylinder use the same axial position reference. The control system calculates the absolute position deviation between the current position feedback value and the actual working position. When the absolute position deviation is not greater than a preset positioning deviation threshold, a valid positioning status signal is generated; when it exceeds the preset positioning deviation threshold, the positioning status signal remains invalid. The preset position adjustment tolerance is only used to determine whether position adjustment needs to be performed after the milling head rotates, while the preset positioning deviation threshold is used for cutting permission and cutting process safety monitoring; the two have different functions.

[0105] Start the negative pressure dust removal device, or keep it running if it is already in operation, to form a suction passage from the dust inlet through the dust removal pipe, the dust removal rotary table and the dust removal main pipe to the negative pressure dust removal device.

[0106] After sending a start command to the negative pressure dust removal device, the system reads the operational feedback output by the device's own control unit. If the negative pressure dust removal device is already running, the system continues to read the operational feedback. When the operational feedback indicates that the negative pressure dust removal device has entered the preset high negative pressure working state, a valid operational status signal is generated. If only a start command is sent but no valid operational feedback is obtained, the negative pressure dust removal device is not determined to be in operation.

[0107] When the five-axis, five-linkage milling head performs its rotational motion, the main dust collection pipe remains fixed relative to the slide, allowing the dust collection duct to rotate with the five-axis, five-linkage milling head. The dust collection rotary table maintains a sealed connection between the dust collection duct and the main dust collection pipe as they rotate relative to each other. Dust generated in the cutting area is sequentially transported to the negative pressure dust collection device via the suction port, dust collection duct, dust collection rotary table, and main dust collection pipe.

[0108] Step 50: Execute and monitor the target cutting segment based on the position status and running status.

[0109] like Figure 4 As shown, before executing each target cutting segment, the position status signal of the servo electric cylinder and the operating status signal of the negative pressure dust removal device are acquired. Cutting feed is only permitted when the position status signal indicates that the dust removal actuator is in the corresponding actual working position, and the operating status signal indicates that the negative pressure dust removal device is in operation. If either condition is not met, the corresponding target cutting segment remains in an inactive state.

[0110] During the execution of the target cutting segment, the current position feedback value of the servo electric cylinder and the operating status signal of the negative pressure dust removal device are continuously read according to the control cycle of the CNC system. The position deviation for the current control cycle is obtained by subtracting the current position feedback value from the actual working position corresponding to the current target cutting segment and taking the absolute value.

[0111] If the positional deviation is not greater than the preset positioning deviation threshold and the operating status signal continuously indicates that the negative pressure dust removal device is in operation, the current target cutting segment continues to be executed and the suction passage remains open. If the positional deviation exceeds the preset positioning deviation threshold, or the operating status signal indicates that the negative pressure dust removal device has stopped operating, the cutting feed is stopped and the tool is controlled to exit the cutting area according to the preset tool retraction path. After the above abnormality handling is completed, any unfinished cutting commands are not executed, and the machining control system waits for further processing.

[0112] If the current target cutting segment is completed but there is still a subsequent target cutting segment, the final stop and reset are not executed; the next segment to be executed is read according to the execution sequence of the five-axis five-linkage machining program. If the next segment to be executed is a cutting segment, the position result of the corresponding target cutting segment is read and the dust removal actuator is adjusted or maintained before cutting; if the next segment to be executed is a tool axis posture switching segment, proceed to step 30; if the next segment to be executed is a tool change segment, proceed to step 60.

[0113] Step 60: Perform tool change and stop and reset the machine after all target cutting segments are completed.

[0114] The preset retraction path used in the tool changing section is the safe retraction path associated with the tool changing command in the tool changing section; the preset tool changing avoidance position is a fixed axial position determined within the stroke range of the servo electric cylinder during the equipment debugging stage, which does not hinder the tool changing action; the specific tool changing mechanical action is executed according to the original tool changing program of the machine tool.

[0115] When a five-axis five-linkage machining program includes a tool change segment, the cutting feed is stopped within the tool change segment, and the tool is controlled to exit the cutting area along a preset retraction path; the servo electric cylinder is controlled to move the dust removal actuator to a preset tool change avoidance position, and the tool change is performed after the dust removal actuator reaches the preset tool change avoidance position.

[0116] Starting from the first interpolation position that has not yet been executed after tool change, following the method described in step 20, the tool sweep area, material removal area, cutting area, available position set, target cutting segment, common available position set, reachable position set, and target working position of the subsequent cutting machining segment are re-determined using the replaced tool parameters. The position results generated for the unexecuted interpolation positions before tool change are no longer used as the control basis after tool change, and the target cutting segment and its position results that have already been executed are not recalculated.

[0117] After the above re-determination is completed, if there is a target cutting segment that has not yet been executed, the next segment to be executed is read according to the execution order of the five-axis five-linkage machining program; before the tool enters the cutting area corresponding to the re-determined next target cutting segment, the dust removal actuator is moved from the preset tool change avoidance position to the target working position corresponding to the target cutting segment, the target working position is determined as the actual working position, and the process proceeds to step 40.

[0118] When it is confirmed that there are no unexecuted target cutting segments according to the execution sequence of the five-axis five-linkage machining program, all target cutting segments are considered completed, and a delay timer is started from the moment the last target cutting segment is completed and the cutting feed stops. During the preset delay time, the negative pressure dust removal device is kept running and the suction passage is kept open to remove residual dust near the cutting area and in the suction passage; after the preset delay time is reached, the negative pressure dust removal device is stopped, the dust removal actuator is moved to the preset reset position, and the dust removal process of this machining is ended.

[0119] In the above manner, the current workpiece occupied area at each interpolation position is updated as the material removal process proceeds. The target cutting segment is divided by the intersection relationship of the available position set. The attitude switching avoidance is determined by the motion occupied area formed by the dust removal actuator as the milling head rotates. The cutting execution is constrained by the position status and the operating status of the negative pressure dust removal device, so that the dust removal position, suction path and operating status correspond to the five-axis five-linkage machining process.

Claims

1. A machining method using a five-axis, five-linkage milling head with high negative pressure dust removal, characterized in that, The milling head is mounted on the slide, which contains a main dust collection pipe. The milling head is equipped with a dust collection rotary table, a dust collection pipe, a servo electric cylinder, and a dust collection actuator driven by the servo electric cylinder and equipped with a dust suction port, including: Acquire five-axis five-linkage machining programs, tool parameters, workpiece geometry data, dust removal actuator geometry data, and machine tool protection area data; identify cutting machining segments, tool axis posture switching segments, and milling head rotation commands. Based on the tool axis posture, machining position, and the aforementioned parameters and data at the interpolation positions of each cutting machining segment, a set of usable positions is formed, consisting of positions where the gap between the dust removal actuator and the current workpiece's occupied area and the machine tool protection area is not less than a preset safety gap, and the minimum distance from the dust inlet boundary to the cutting area is within a preset dust removal distance range. If any set of usable positions is empty, the corresponding cutting machining segment is prohibited from execution. Otherwise, consecutive interpolation positions whose intersection remains non-empty are divided into the same target cutting segment, and the intersection of the common usable position set and the preset maximum stroke-limited stroke range is taken as the reachable position set. If the reachable position set is empty, the corresponding target cutting segment is prohibited from execution. When the reachable location set is not empty, the actual working position is determined from it and the dust removal actuator is in place. The negative pressure dust removal device is started or kept running, forming a suction passage from the dust inlet through the dust removal pipe, dust removal rotary table and dust removal main pipe to the negative pressure dust removal device. During the target cutting section, the suction passage is kept open by the dust removal rotary table during the rotation of the milling head; Within the tool axis posture switching segment, the tool retracts, and the area occupied by the dust removal actuator as the milling head rotates is determined. It is then determined whether the gap between the dust removal actuator and the current workpiece area and the machine tool protection area before the posture switching is not less than the preset safety gap. If so, the current position is maintained and the milling head is rotated. Otherwise, the tool is moved to the preset posture switching avoidance position, and the milling head is rotated again after the condition is met. Before executing the next target cutting segment after rotation, the actual working position is determined according to the reachable position set of the next target cutting segment, and the dust removal actuator is adjusted or kept in place.

2. The machining method for a five-axis, five-linkage milling head with high negative pressure dust removal according to claim 1, characterized in that, Identifying the cutting process segment and the tool axis posture switching segment includes: Extract the machining motion program segments from the five-axis five-linkage machining program, and exclude program segments containing tool change instructions and corresponding tool change positioning program segments; The remaining machining motion program segment where the spindle is at the cutting speed and the tool moves along the machining trajectory according to the cutting feed command is defined as the cutting machining segment; The remaining machining motion program segments associated with adjacent cutting segments, including stopping the cutting feed, controlling the tool to exit the cutting area, and executing the milling head rotation command, are defined as the tool axis posture switching segments.

3. The machining method for a five-axis, five-linkage milling head with high negative pressure dust removal according to claim 1, characterized in that, Tool parameters include tool geometry parameters and tool length compensation values, and workpiece geometry data includes initial workpiece geometry data; Determine the current workpiece occupied area, available position set, target cutting segment, reachable position set, and target working position, including: The initial workpiece occupied area is determined based on the initial workpiece geometry data, and the initial workpiece occupied area is used as the current workpiece occupied area before machining at the starting interpolation position. According to the execution order of the interpolation positions, the tool sweep area between the current interpolation position and the next interpolation position is determined based on the tool parameters. The overlapping area between the tool sweep area and the current workpiece occupied area is determined as the material removal area. The material removal area is subtracted from the current workpiece occupied area to obtain the current workpiece occupied area before machining at the next interpolation position. The cutting area is determined based on the tool parameters, tool axis posture, machining position, and the current workpiece area. The machine tool protection area is determined based on the machine tool protection area data. Along the servo cylinder drive direction, the available positions are formed by the gap between the dust removal actuator and the current workpiece area and the machine tool protection area that is not less than the preset safety gap, and the minimum distance from the dust inlet boundary to the cutting area that is within the preset dust removal distance range. Starting from the initial interpolation position, sequentially calculate the intersection of the available position sets; when adding the next interpolation position to make the intersection empty, take the previous interpolation position as the end point of the current target cutting segment and the next interpolation position as the start point of the next target cutting segment; The intersection of the common available positions of each target cutting section and the stroke range is taken as the reachable position set; the direction in which the dust suction port is close to the cutting area is taken as the extension direction. When the reachable position set is not empty, the position that is the foremost along the extension direction is determined as the target working position.

4. The machining method of a five-axis, five-linkage milling head with high negative pressure dust removal according to claim 3, characterized in that, When the set of available positions for any interpolation position is empty, a position unavailable message is generated, and the cutting segment containing that interpolation position is prohibited from execution. When the intersection of the common available position set of the target cutting segment and the travel range is empty, dust removal actuator position over-limit information is generated, and the execution of the corresponding target cutting segment is prohibited.

5. The machining method for a five-axis, five-linkage milling head with high negative pressure dust removal according to claim 3, characterized in that, Determining whether the preset safety clearance is met between the moving area and the current workpiece area and the machine tool protection area includes: Based on the current tool axis posture, the next tool axis posture, the milling head rotation command, the geometric data of the dust removal actuator, and the current position of the dust removal actuator, determine the motion area occupied by the dust removal actuator when it transitions from the current tool axis posture to the next tool axis posture; Obtain the current workpiece occupied area before the attitude switching begins, and determine the two minimum distances between the motion occupied area and the current workpiece occupied area and the machine tool protection area, respectively; When the moving area overlaps with the current workpiece area or the machine tool protection area, or when the minimum distance in any one of these conditions is less than the preset safety gap, it is determined that the preset safety gap is not met. When there is no overlap and both minimum distances are not less than the preset safety gap, the preset safety gap is determined to be satisfied.

6. The machining method of a five-axis, five-linkage milling head with high negative pressure dust removal according to claim 5, characterized in that, When the movement occupancy area determined based on the current position of the dust removal actuator does not meet the preset safety clearance, the servo electric cylinder is controlled to move the dust removal actuator to the preset attitude switching avoidance position; Based on the preset posture switching avoidance position, the area occupied by the dust removal actuator during the milling head rotation process is redefined; When the newly determined motion occupancy area meets the preset safety clearance with the current workpiece occupancy area and the machine tool protection area respectively, the milling head rotation command is executed; when either is not met, a posture switching avoidance failure message is generated and the execution of the milling head rotation command is prohibited. After the milling head completes its rotation, the dust removal actuator is moved to the corresponding target working position according to the set of reachable positions for the next target cutting segment, or the current position is maintained when the current position belongs to the set of reachable positions, and the position after moving or maintaining is determined as the actual working position.

7. The machining method for a five-axis, five-linkage milling head with high negative pressure dust removal according to claim 5, characterized in that, When the movement occupancy area determined based on the current position of the dust removal actuator satisfies the preset safety clearance, the dust removal actuator remains in its current position and the milling head rotates. After the milling head has rotated, it is determined whether the current position of the dust removal actuator belongs to the reachable position set of the next target cutting segment, and the absolute position difference between the current position and the target working position corresponding to the next target cutting segment along the driving direction of the servo electric cylinder is determined. When the current position belongs to the set of reachable positions and the absolute position difference is not greater than the preset position adjustment tolerance, the current position is determined as the actual working position of the next target cutting segment and remains unchanged. When the current position does not belong to the set of reachable positions, or when the absolute position difference is greater than the preset position adjustment tolerance, the dust removal actuator is moved to the target working position corresponding to the next target cutting segment, and the target working position is determined as the actual working position.

8. The machining method of a five-axis, five-linkage milling head with high negative pressure dust removal according to claim 1, characterized in that, Maintaining the suction passage connected by the dust removal rotary table during the milling head rotation includes: When the five-axis five-linkage milling head performs the milling head rotation motion, the dust removal main pipe is kept fixed relative to the slide, and the dust removal pipe rotates with the five-axis five-linkage milling head; The dust removal rotary table maintains a sealed connection between the dust removal duct and the main dust removal pipe as they rotate relative to each other. The dust generated in the cutting area is sequentially transported to the negative pressure dust removal device through the dust suction port, dust removal pipe, dust removal rotary table and dust removal main pipe.

9. The machining method of a five-axis, five-linkage milling head with high negative pressure dust removal according to claim 3, characterized in that, When the five-axis five-linkage machining program contains a tool change command, the tool change segment is identified based on the tool change command and its associated tool change positioning command, and is excluded from the cutting machining segment and the tool axis posture switching segment, and is executed within the tool change segment: Stop the cutting feed and control the tool to exit the cutting area along a preset retraction path; The dust removal actuator is moved to a preset tool change avoidance position, and the tool change is performed after reaching the preset tool change avoidance position; After the tool change is completed, the tool geometry parameters and tool length compensation value of the replaced tool are obtained, and the cutting area, available position set, target cutting segment, reachable position set and target working position of the subsequent cutting process are re-determined based on the replaced tool parameters. Before the tool enters the cutting area corresponding to the next target cutting segment, the dust removal actuator is moved from the preset tool change avoidance position to the target working position corresponding to the target cutting segment, and the target working position is determined as the actual working position.

10. The machining method of a five-axis, five-linkage milling head with high negative pressure dust removal according to claim 1, characterized in that, Before executing each target cutting segment, the position status signal of the servo electric cylinder and the operating status signal of the negative pressure dust removal device are obtained. Cutting feed is allowed only when the position status signal indicates that the dust removal actuator is in the corresponding actual working position and the operating status signal indicates that the negative pressure dust removal device is in operation. During the execution of the target cutting segment, the current position of the servo electric cylinder and the running status signal are acquired, and the absolute position deviation between the current position and the corresponding actual working position along the driving direction of the servo electric cylinder is determined. When the absolute position deviation exceeds the preset positioning deviation threshold, or when the negative pressure dust removal device stops operating, the cutting feed is stopped and the tool is controlled to exit the cutting area along the preset retraction path; After all target cutting sections are completed, the negative pressure dust removal device is kept running for a preset delay time, then the negative pressure dust removal device is stopped, and the dust removal actuator is moved to a preset reset position.

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