Processing system

Abstract

Provided is a processing system that improves accuracy in identification of specific cutting resistance by automatically determining a region for identifying the specific cutting resistance, and consequently improves accuracy in estimation of a processing load.　A processing system (10) comprises: a simulation unit (12) having a motion step generation unit (44), a processing load estimation unit (38) that estimates a processing load, a specific cutting resistance storage unit (46) that stores a specific cutting resistance, and a specific cutting resistance identification unit (48) that identifies the specific cutting resistance on the basis of an actual processing load (PL2); and a machine tool (16) having an identification region determination unit (14) that, on the basis of an assessment condition, assesses whether a motion step is suitable for identification of the specific cutting resistance, and then determines, as an identification region for identification of the specific cutting resistance, a motion step group that continues over a processing length threshold value or more, a control device (20) that controls a machine device (18), and a detection unit (32) that detects the actual processing load (PL2).

Description

Processing System

[0001] The present invention relates to a processing system.

[0002] When machining a workpiece with a machine tool, it is necessary to monitor the machining to determine whether the machining load is appropriate. If the monitoring result indicates that the machining load is higher than a monitoring standard, an abnormality is determined and the machine is stopped, or the machining conditions for the next machining cycle are lowered to reduce the machining load and stabilize the machining. On the other hand, if the machining load is lower than the set monitoring standard, the machining conditions for the next machining cycle are improved to shorten the machining time. When monitoring machining, it is preferable to set the monitoring standard in advance of actual machining. Therefore, conventionally, the monitoring standard is set by estimation using a nominal specific cutting resistance. However, in actual machining, the machining load often cannot be accurately estimated due to variations in the physical properties of the actual workpiece and differences in various specifications such as the clearance angle and rake angle of the tool used in machining.

[0003] Cited Document 1 discloses an invention in which specific cutting resistance, which is a cutting force coefficient for each combination of tool and material, is estimated based on shape data of test pieces machined by a test program and compiled into a database. However, this processing method requires a separate measurement process and measuring device to obtain the shape data of the test pieces, which increases the number of work steps and costs.

[0004] Furthermore, in order to make the accuracy of the identification of the specific cutting resistance closer to reality, it is preferable that the machining load of the actual machining used for identifying the specific cutting resistance is stable. For this reason, it is necessary to perform machining in a portion (area) where the machining load is less likely to vary. However, there are no clear standards or techniques for determining which areas are suitable for identification and how to determine which areas are suitable.

[0005] Japanese Patent Application Laid-Open No. 2022-087704

[0006] In view of the above circumstances, an object of the present invention is to provide a machining system that improves the accuracy of identifying the specific cutting resistance by automatically determining an area for identifying the specific cutting resistance, and thereby improves the accuracy of estimating the machining load.

[0007] According to one aspect of the present invention, there is provided a machining system that executes a machining program on a machine tool and performs machining on a workpiece using a tool, the machining system including: a machine tool having a machine that performs actual machining on the workpiece based on the machining program; a control device that controls the machine; and a detection unit that detects actual machining loads generated on the machine corresponding to motion steps into which the machining program is subdivided and stores the detected loads in the control device; a simulation unit that has: a motion step generation unit that generates motion steps; a machining load estimation unit that estimates the machining load on the machine for each motion step when the machining program is executed; a specific cutting resistance storage unit that stores specific cutting resistances used for the estimation in correspondence with tool information and workpiece information; and a specific cutting resistance identification unit that identifies the specific cutting resistance based on the actual machining load generated during actual machining; and an identification region determination unit that determines based on a determination condition whether the motion steps are suitable for detecting the actual machining load used for identifying the specific cutting resistance, and then determines a group of consecutive motion steps that are equal to or longer than a pre-stored machining length threshold as an identification region suitable for actual machining in which the actual machining load is acquired for identifying the specific cutting resistance.

[0008] According to one aspect of the present invention, the machining system's simulation unit includes a motion step generation unit and a machining load estimation unit, which can generate motion steps by dividing a machining program and estimate an estimated machining load on a machine tool for each motion step. Furthermore, the machine tool of the machining system includes a control device and a detection unit for controlling the machine tool. The detection unit can detect actual machining loads on the machine tool corresponding to a motion step group, which is a collection of motion steps, and store the detected loads in the control device. The machining system's identification region determination unit is configured to determine, based on a judgment condition, whether a motion step is suitable for detecting an actual machining load used to identify a specific cutting resistance. Therefore, among the motion step groups, which are collections of motion steps determined to be identifiable based on the judgment condition, a group of consecutive motion steps that is equal to or longer than a pre-stored machining length threshold can be determined as an identification region suitable for actual machining to obtain an actual machining load for identifying a specific cutting resistance. This automatically determines the region for identifying a specific cutting resistance, thereby improving the accuracy of the specific cutting resistance identification and the accuracy of machining load estimation.

[0009] FIG. 1 shows a block diagram of a machining system according to this embodiment. FIG. 2 shows an example of a machining program according to this embodiment. FIG. 3 shows an example of a data file according to this embodiment. FIG. 4 shows an example of specific cutting resistance data according to this embodiment. FIG. 5 shows an example of interference information according to this embodiment. FIG. 6 shows an example of a machining drawing. FIG. 7 shows a flowchart of the machining system according to this embodiment.

[0010] Hereinafter, a processing system according to an embodiment will be described with reference to the accompanying drawings. Similar or corresponding elements are designated by the same reference numerals, and duplicated explanations will be omitted. For ease of understanding, the scale of the drawings may be changed.

[0011] FIG. 1 shows a block diagram of a machining system 10 according to this embodiment. The machining system 10 executes a machining program (see FIG. 2) on a machine tool 16, operates a tool TL in accordance with commands from the machining program, and machines a workpiece W. The machining system 10 is configured to detect an actual machining load PL2, which is the load actually generated during machining on a machine device 18 that machines the workpiece W, and to estimate an estimated machining load PL1 in advance. The machining system 10 also sets a monitoring band BM of the machining load based on the estimated machining load PL1 and monitors whether the detected actual machining load PL2 exceeds or falls below the monitoring band BM. Therefore, the machining system 10 includes a simulation unit 12 for estimating the estimated machining load PL1 and a machine tool 16 electrically connected to the simulation unit 12 and for actually machining the workpiece W (hereinafter referred to as actual machining). In this specification, "machining load" refers to the load generated on the machine device 18 when machining the workpiece W using the tool TL, but depending on the context, it may also be expressed as an "estimated machining load" that is a machining load estimated in advance, or an "adjusted machining load" that is an adjusted estimated machining load. Therefore, "machining load" is a concept that encompasses "cutting resistance," "cutting load," "machining resistance," etc.

[0012] The machine tool 16 includes a machine device 18 that performs actual machining on the workpiece W, and a control device 20 that controls the machine device 18. Here, as an example, the machine device 18 is a horizontal cutting machine. The machine device 18 includes a bed 22 that serves as a base, and a column 24 that stands on the upper surface of the bed 22. A table 28 is disposed on the upper surface of the bed 22 for fixing the workpiece W, which is the object to be machined, with a fixture (not shown). The table 28 is configured to be movable on the bed 22 via a guide surface.

[0013] The mechanical device 18 has preset machine coordinates with a predetermined position as the origin, and includes an X-axis, a Y-axis, and a Z-axis as linear axes that are orthogonal to each other. Here, the Z-axis extends horizontally (left-right on the paper). The X-axis and Y-axis are set on a plane perpendicular to the Z-axis, i.e., on a vertical plane. In the mechanical device 18, the column 24 is configured to move along the X-axis direction (perpendicular to the paper). A saddle (not shown) is disposed on the front of the column 24, and is configured to be movable along the Y-axis direction (up-down on the paper).

[0014] A spindle head (not shown) is disposed in front of the saddle of the machine device 18, and a spindle 26 configured to be rotatable about an axis parallel to the Z axis is attached to the tip side of the spindle head. A tool TL for machining a workpiece W while rotating together with the spindle 26 is detachably attached to the spindle 26. The machine device 18 is configured so that the spindle 26 for attaching the tool TL and a table 28 on which the workpiece W is placed can move relatively along the X axis, Y axis, and Z axis.

[0015] The machine device 18 also has a tool changer 30 for performing a wide variety of machining operations according to the machining purpose, and the tool changer 30 is configured to be able to change the tool TL attached to the spindle 26. Furthermore, the machine device 18 has a detection unit 32 configured to calculate (detect) the actual machining load PL2 from the load generated in a motor (not shown) that drives the spindle 26 and a motor that drives a linear motion mechanism and a rotation mechanism (not shown) that move the spindle and the table relative to each other.

[0016] The machining system 10 includes a CAM (Computer Aided Manufacturing) system 34 for generating a machining program (see FIG. 2 ) based on information about the workpiece W to be machined. An operator of the machining system 10 inputs information necessary for machining, such as model data about the workpiece W, workpiece material information, and workpiece model number information, into the CAM system 34 to generate the machining program. Here, the information necessary for machining may further include information about a jig (not shown) for mounting the workpiece W, for the purpose of performing detailed interference checks between the tool TL and the workpiece W. Once the machining program is generated, the CAM system 34 transmits (inputs) it to the simulation unit 12 together with model data of the workpiece W, etc. Note that the operator may directly create a machining program based on their experience and input it to the simulation unit without using the CAM system 34.

[0017] The simulation unit 12 simulates the machining program. To this end, the simulation unit 12 has an interference checking unit 36 ​​and a motion step generating unit 44. The motion step generating unit 44 generates motion steps that subdivide the contents of the machining program. FIG. 2 shows an example of a machining program (program number: O3001). Here, a motion step is generated each time the linear movement distance in the machining program changes by a certain amount. Note that, in the following description, the motion steps are generated based on the linear movement distance, but this is not limiting and the motion steps may be generated based on, for example, the elapsed time in the simulation.

[0018] FIG. 3 shows an example of a data file recording motion steps (columns DF0 to DF7 in FIG. 3 ) generated in accordance with a machining program, machining loads (columns DF8 and DF9 in FIG. 3 ), and judgment results based on judgment conditions (columns DF10 to DF12 in FIG. 3 ). The simulation unit 12 records the generated motion steps in a data file in accordance with the generation of the motion steps. For each subdivided motion step (each serial number in column DF0 in FIG. 3 ), the data file records the program number (column DF1 in FIG. 3 ), the corresponding sequence number in the machining program (column DF2 in FIG. 3 ), the tool number of the tool TL used in machining (column DF3 in FIG. 3 ), and the material of the workpiece W being machined (column DF4 in FIG. 3 ). The data file also records the X coordinate (column DF5 in FIG. 3 ), Y coordinate (column DF6 in FIG. 3 ), and Z coordinate (column DF7 in FIG. 3 ) of the tool TL, which moves linearly based on the machining program. Here, as an example, a motion step is generated for each linear movement distance of 0.2 mm.

[0019] The simulation unit 12 further includes a machining load estimator 38 and a specific cutting resistance memory 46, which are used to generate the motion steps and simultaneously estimate the estimated machining load PL1. When estimating the machining load as the estimated machining load PL1, the machining load estimator 38 estimates the estimated machining load PL1 for each motion step based on the specific cutting resistance stored in the specific cutting resistance memory 46 and the cutting area of ​​the tool TL calculated by the interference checker 36. FIG. 4 shows an example of the specific cutting resistance stored in the specific cutting resistance memory 46. Here, the specific cutting resistance is stored for each workpiece W and each workpiece W to be machined, and the specific cutting resistance corresponding to these is used to estimate the estimated machining load PL1. Here, the specific cutting resistances of tools T1 and T3 have been identified relative to FC250, but the specific cutting resistance of tool T2 has not been identified relative to FC250. Therefore, the nominal value kc is used for the specific cutting resistance of tool T2 relative to FC250. In other words, the specific cutting resistance of the tool T2 is required to be identified. The estimated machining load PL1 thus estimated is recorded in a data file (column DF8 in FIG. 3). Note that, here, the specific cutting resistance is described as a value defined for each combination of the material of the tool TL and the workpiece W, as shown in FIG. 4, but is not limited to this, and the specific cutting resistance may be defined for each of a plurality of other parameters, for example.

[0020] FIG. 5 shows an example of interference information. The interference checking unit 36 ​​generates interference information (CWE: Cutter-Workpiece Engagement) between the tool TL and the workpiece W based on the machining program and model information in conjunction with the generation of the motion steps. Based on this interference information, the interference checking unit 36 ​​stores (records) the axial cutting depth (column CW1 in FIG. 5 ) and radial cutting depth (column CW2 in FIG. 5 ) of the tool TL in each motion step (serial numbers in column CW0 in FIG. 5 ), and calculates the cutting area in each motion step from this information. While the interference in this embodiment is very simple, in cases where the radial cutting depth varies depending on the axial position of the tool, such as when machining an oblique wall portion with a square end mill, the radial cutting depth and axial cutting depth can also be calculated based on the engagement angle and disengagement angle at each tool axial position. Furthermore, the interference checking unit 36 ​​can check for interference such as unintended collisions between the workpiece W, the tool TL, the machine device 18, etc., separately from interference due to cutting.

[0021] The simulation unit 12 sets upper and lower limits based on the estimated processing load PL1 to determine the monitoring band BM. The monitoring band BM is calculated by adding and subtracting a predetermined percentage (e.g., ±5%) that is set and stored in advance from the estimated processing load PL1. The difference between the upper limit UV and the lower limit LV is the bandwidth of the monitoring band BM.

[0022] The control device 20 includes a monitoring unit 52, and is able to monitor actual machining by checking whether the actual machining load PL2 detected by the detection unit 32 is within the monitoring band BM. When the actual machining load PL2 monitored by the monitoring unit 52 is greater than the upper limit UV or smaller than the lower limit LV, the control device 20 determines that an abnormality has occurred in the mechanical device 18 because the actual machining load PL2 exceeds the upper limit or falls below the lower limit of the monitoring band BM, and stops the mechanical device 18.

[0023] The simulation unit 12 has an identification region determination unit 14, which is configured to determine, based on the judgment conditions, whether each motion step is suitable for detecting the machining load used to identify the specific cutting resistance, and then determine the motion step as the identification region. Therefore, when the generation of the motion steps is completed, the identification region determination unit 14 of the simulation unit 12 determines, based on the judgment conditions, whether each motion step is suitable for detecting the machining load used to identify the specific cutting resistance, and then determines the identification region. The simulation unit 12 inputs a machining program ( FIG. 2 ) and a data file ( FIG. 3 ) to the control device 20 of the machine tool 16. The control device 20 operates the machine device 18 and actually machines the workpiece W based on the input machining program and data file.

[0024] Three judgment conditions are set for the identification region determination unit 14. The first judgment condition is whether or not the material surface is machined in each motion step. The material surface refers to a region that has never been machined, such as the uncut portion of a cast workpiece W. Uncut portions have unstable shapes and hardness, resulting in unstable machining loads. Therefore, they are not suitable for use as regions for detecting machining loads used to identify specific cutting resistance. When generating interference information ( FIG. 5 ) in conjunction with motion step generation, the simulation unit 12 can, for example, update the shape of the workpiece model in accordance with machining, and include information on whether each motion step will machine the material surface in the interference information. Therefore, by referring to the interference information, the current motion step is determined to be suitable for detecting the machining load used for identification if it is not machining the material surface, i.e., if the current motion step is a region that has already been surface-machined at least once and will undergo surface machining again. This judgment condition is set as the first judgment condition. This judgment may be performed simultaneously when each motion step is generated. In the example of the data file according to this embodiment shown in Fig. 3, the group of motion steps at sequence number N1203 of tool T2 for which identification is desired (the portion enclosed by a square in Fig. 3) is a process performed after machining the material surface at sequence number N1103 of tool T1, and does not correspond to machining of the material surface, so it has been determined to be suitable for detecting the machining load to be used for identification. Therefore, an x ​​mark indicating that the group is not suitable for detecting the machining load to be used for identification is recorded in the portion of column DF10 in Fig. 3 corresponding to sequence number N1103, and a circle mark indicating that the group is suitable for detecting the machining load to be used for identification is recorded in the portion of column DF10 corresponding to sequence number N1203.

[0025] The second judgment condition is whether or not finish machining is performed in each motion step. In actual machining, which acquires the machining load for identifying the specific cutting machining, the actual machining load PL2 may be acquired by varying the cutting feed rate over a fixed machining length, resulting in an inconsistent machining surface quality. As a result, if the surface quality does not meet the required accuracy, the workpiece W may have to be discarded. Therefore, after generating all motion steps, each motion step is judged to be a finish machining step based on coordinate information, interference information, etc., and if not, is judged to be suitable for detecting the machining load used for identification. This judgment condition is set as the second judgment condition. In the example data file shown in FIG. 3 according to this embodiment, the motion step group at sequence number N1203 of tool T2 (enclosed in a square in FIG. 3 ) for which identification is desired is semi-finishing, followed by finishing machining at sequence number N1303 of tool T3. Therefore, the motion step group at sequence number N1203 does not correspond to finishing machining and is therefore judged to be suitable for detecting the machining load used for identification. Therefore, in the example of the data file in Figure 3, in column DF11 of the data file in Figure 3, which shows the second judgment condition, a circle mark is recorded for sequence number N1203, indicating that it is suitable for detecting the processing load used for identification, and an cross mark is recorded for sequence number N1303, indicating that it is not suitable for detecting the processing load used for identification.

[0026] The third judgment condition is whether the machining amount of each motion step is stable. Here, the machining amount refers to, for example, the tool axial depth of cut and the tool radial depth of cut in the case of surface machining using a cutter tool. The machining amount can be obtained from interference information generated when the motion steps are generated. Furthermore, the difference between the machining amount of the motion step to be evaluated and the motion step immediately preceding it can be calculated from the interference information, thereby ascertaining the fluctuation in the machining amount. Therefore, if the fluctuation in the machining amount is smaller than a predetermined and stored fluctuation threshold, preferably zero, the machining amount is deemed stable and is determined to be suitable for detecting the machining load used for identification. This judgment condition is set as the third judgment condition. In the example data file shown in FIG. 3 according to this embodiment, the motion step at sequence number N1203 of tool T2 to be identified performs semi-finishing machining, in which tool T1 performs machining using sequence number N1103, followed by further cutting in the Z direction (tool axial direction) and moving only in the Y direction. FIG. 6 schematically shows the machining diagram for sequence number N1203. Because the tool axial and radial depths of cut are constant from Y30.0 to Y44.0 within N1203, it can be determined that the machining volume fluctuations are zero and stable. Therefore, in column DF12 in Figure 3 , which shows the third judgment condition, a circle is recorded for Y30.0 to Y31.0 within sequence number N1203, indicating that the sequence is suitable for detecting the machining load used for identification. Although omitted from Figure 3 , a circle is also recorded for the motion steps from Y coordinate 31.0 to Y44.0. Here, it is important to determine the machining volume based on the stability of both the radial and axial depths of cut. This is because, even if the radial and axial machining volumes fluctuate, there may be cases where the chip removal rate per unit time is consistent. However, in this case, the direction of action of the machining load fluctuates, resulting in an unstable actual machining load PL2.

[0027] After the determination based on the three determination conditions is completed, the identification area determination unit 14 extracts, from among the motion steps that satisfy all three determination conditions, motion steps that continue for a predetermined machining length threshold or more as a motion step group and determines the extracted motion step group as the identification area (the area surrounded by a square in Figure 3). Since the actual machining load PL2 at a certain machining length or more is required to identify the specific cutting resistance, a machining length threshold must be set to determine the identification area based on this. In the example shown in Figure 3, the machining length threshold is set to 10 mm. In the data file of this embodiment, for sequence number N1203 of tool T2 to be identified, as shown in Figure 6, the spindle and tool move from Y20.0 to Y50.0 to perform machining. Of these, machining from Y30.0 to Y44.0 satisfies all three determination conditions and the machining length is 14 mm, so the motion step group in this machining path can be determined as the identification area. If there are multiple motion step groups determined as the identification region, the identification region determination unit 14 may automatically determine the motion step group with the longest machining length as the identification region. Alternatively, the identification region determination unit 14 may notify the operator that there are multiple motion step groups determined as the identification region, and prompt the operator to determine a motion step group that will perform actual machining for identification from the multiple motion step groups.

[0028] Furthermore, according to the machining system 10 of this embodiment, the identification region determination unit 14 is configured to identify the specific cutting resistance based on multiple actual machining loads PL2 detected during multiple actual machining operations. This is because, even in a stable region, sudden tool breakage or other issues during actual machining can cause noise in the actual machining load PL2 data. Therefore, the control device 20 of the machine tool 16 stores a predetermined number of runs, executes the machining program the predetermined number of times, and acquires multiple actual machining loads PL2. Furthermore, according to the machining system 10, the display unit (not shown) is configured to visualize the multiple actual machining loads PL2 in chronological order. Therefore, after the operator checks for the presence or absence of noise and manually removes it, the multiple actual machining loads PL2 can be averaged, recorded in a data file, and input to the specific cutting resistance identification unit 48. Furthermore, if the control device 20 of the machine tool 16 can determine that the difference between a plurality of actual machining loads PL2 is smaller than a predetermined machining load threshold value and that there is no noise, the noise removal process can be omitted without the intervention of an operator, and the actual machining loads PL2 from a plurality of times can be averaged, recorded in a data file, and input to the specific cutting resistance identification unit 48.

[0029] The simulation unit 12 may also include an optimization unit 40 and a machine information storage unit 42. When the estimated machining load PL1 exceeds the allowable machining load set in the machine information storage unit 42 of the machine tool 16, the optimization unit 40 is configured to slow down the machining speed in the machining program so as not to exceed the allowable machining load. Furthermore, when the estimated machining load PL1 is below the allowable machining load, the optimization unit 40 is configured to increase the machining speed in the machining program within a range that does not exceed the allowable machining load. Furthermore, in both cases where the estimated machining load PL1 exceeds or falls below the allowable machining load, the machining program is not automatically optimized and can be returned to the CAM system 34 or an operator. Because these optimizations are performed based on the estimated machining load PL1, improving the accuracy of identifying the specific cutting resistance is also important in optimization. Furthermore, if the simulation unit 12 confirms interference as an unintended collision between the workpiece W, tool TL, and machine device 18 when executing the machining program using the interference confirmation unit 36, it can return the program to the program generation process, i.e., the CAM system 34 or the operator.

[0030] The effects of the machining system 10 according to this embodiment will be described below through an explanation of the machining process of the workpiece W using the flowchart of the machining system 10 shown in FIG.

[0031] First, the process proceeds to step S10, where the machining process is started, and then to step S20, where the CAM system 34 generates a machining program. Next, the process proceeds to step S30, where the CAM system 34 inputs the machining program and model data to the simulation unit 12.

[0032] Next, the process proceeds to step S40, where the motion step generation unit 44 generates motion steps one by one based on the machining program. Next, the process proceeds to step S50, where the simulation unit 12 checks the identification results stored in the data file and the specific cutting resistance storage unit 46, i.e., whether or not the specific cutting resistance corresponding to the tool TL used in the motion step and the workpiece W to be machined has been previously identified. If the identification results exist, the process proceeds to step S60, where the simulation unit 12 estimates an estimated machining load PL1 for the motion step using the identified specific cutting resistance. On the other hand, if the identification results do not exist, the process proceeds to step S80, where the simulation unit 12 estimates an estimated machining load PL1 for the motion step using a nominal specific cutting resistance that has not been identified. Once the estimated machining load PL1 has been estimated, the process proceeds to step S70, where it is confirmed whether generation of all motion steps has been completed. The simulation unit 12 repeats steps S40 to S80 until generation of all motion steps has been completed.

[0033] When the generation of all motion steps is completed, the process proceeds to step S90, where the identification area determination unit 14 determines whether each motion step is suitable for identification based on the determination conditions, and determines the identification area based on the result.

[0034] Once the identification area has been determined, the process proceeds to step S100, where the simulation unit 12 inputs the optimized machining program and a data file including the motion step information, the identification area, and the estimated machining load PL1 to the control device 20 of the machine tool 16.

[0035] When the input to the control device 20 is completed, the process proceeds to step S110, and the machine device 18 performs actual machining based on the machining program. Accordingly, the monitoring unit 52 monitors the actual machining load PL2 detected by the detection unit 32, and the actual machining load PL2 in at least the motion step group corresponding to the identification region is stored in the machining load storage unit 54.

[0036] When machining is completed, the process proceeds to step S120, where the control device 20 of the machine tool 16 additionally records the actual machining load PL2 in the data file and inputs this to the specific cutting resistance identifying unit 48. When the actual machining load PL2 is input, the specific cutting resistance identifying unit 48 proceeds to step S130, where it identifies (specifies) the specific cutting resistance based on the motion step, actual machining load PL2, and interference information in the data file. Once the specific cutting resistance is identified, the identified specific cutting resistance is stored in the specific cutting resistance storage unit 46 together with the fact that identification has been performed.

[0037] According to the machining system 10 of this embodiment, the simulation unit 12 of the machining system 10 has a motion step generation unit 44 and a machining load estimation unit 38, and is able to generate motion steps by dividing a machining program and estimate the machining load generated on the mechanical device 18 of the machine tool 16 for each motion step. Furthermore, the machine tool 16 of the machining system 10 has a control device 20 and a detection unit 32 that control the mechanical device 18, and the detection unit 32 can detect an actual machining load PL2 generated on the mechanical device 18 corresponding to a motion step group, which is a collection of motion steps, and store the detected actual machining load PL2 in the control device 20. Therefore, the machining system 10 can set a monitoring band BM of the machining load based on the estimated machining load PL1, and monitor whether the detected actual machining load PL2 exceeds or falls below the monitoring band BM.

[0038] Furthermore, in the machining system 10 according to this embodiment, the identification region determination unit 14 of the machining system 10 is configured to determine whether a motion step is suitable for detecting the actual machining load PL2 used to identify the specific cutting resistance based on three determination conditions. Therefore, among the motion step groups, which are a set of motion steps determined to be identifiable based on these determination conditions, a group of consecutive motion steps that are equal to or longer than a pre-stored machining length threshold can be determined as the identification region for acquiring the actual machining load PL2 for identifying the specific cutting resistance. This automatically determines the region for identifying the specific cutting resistance, improving the accuracy of the identification of the specific cutting resistance and the accuracy of estimating the estimated machining load PL1. In other words, the actual machining load PL2 can be monitored accurately by the monitoring unit 52.

[0039] Furthermore, according to the machining system 10 of this embodiment, when actual machining is performed for the motion step group determined as the identification region, the detection unit 32 detects the actual machining load PL2 corresponding to the motion step and stores the detected load in the machining load memory unit 54 of the control device 20 of the machine tool 16. At this time, the control device 20 of the machine tool 16 can also vary the cutting feed rate in the motion step group to increase the variety of the actual machining load PL2 acquired. Specifically, the cutting feed rate commanded by the NC program can be set to 100%, and the cutting feed rate can be varied using the override function of the machine tool 16 within a range below 100%, for example, 50%, 75%, and 100%, so as not to exceed the allowable load of the machine tool 16. After the actual machining is completed, the control device 20 of the machine tool 16 can add the actual machining load PL2 to a data file and input it to the simulation unit 12.

[0040] Furthermore, according to the machining system 10 of this embodiment, the specific cutting resistance identifying unit 48 of the simulation unit 12 can identify the specific cutting resistance based on the actual machining load PL2, and store information that the identification has been performed together with the information in the specific cutting resistance storage unit 46. Therefore, in the subsequent machining steps, the specific cutting resistance identified by the specific cutting resistance identifying unit 48 can be used to estimate the estimated machining load PL1 for the same combination of tool TL and workpiece W (in this embodiment, the combination of tool T2 and workpiece FC250).

[0041] Furthermore, in the machining system 10 according to this embodiment, the identification region determination unit 14 is configured to be able to identify the specific cutting resistance based on a plurality of actual machining loads PL2 detected in a plurality of actual machining operations. Furthermore, the display unit is configured to be able to visualize the plurality of actual machining loads PL2 in chronological order, and the operator can check for the presence or absence of noise, manually remove the noise, and then average the plurality of actual machining loads PL2, record the average in a data file, and input the average to the specific cutting resistance identification unit 48. Therefore, even if noise occurs due to unexpected tool breakage or the like during actual machining, the noise can be removed and the specific cutting resistance can be identified.

[0042] As described above, the machining system 10 according to this embodiment improves the accuracy of identifying the specific cutting resistance by automatically determining the area for identifying the specific cutting resistance, and in turn, can increase the accuracy of estimating the estimated machining load PL1, and can accurately monitor the actual machining load PL2 by the monitoring unit 52.

[0043] Here, whether the area is suitable for detecting the processing load used for identification is determined based on three determination conditions, but this is not limited to this, and the determination may be made based on only one of the three determination conditions, or four or more determination conditions may be imposed.

[0044] Although an embodiment of the machining system 10 has been described above, the present invention is not limited to the above embodiment. For example, a horizontal machine tool with a vertical spindle may be used instead of a vertical machine tool with a horizontal spindle. In addition to the above, those skilled in the art will understand that various modifications of the above embodiment are possible.

[0045] REFERENCE SIGNS LIST 10 Machining system 12 Simulation unit 14 Identification area determination unit 16 Machine tool 18 Machine device 20 Control device 32 Detection unit 36 ​​Interference confirmation unit 38 Machining load estimation unit 44 Motion step generation unit 46 Specific cutting resistance storage unit 48 Specific cutting resistance identification unit 52 Monitoring unit 54 Machining load storage unit PL1 Estimated machining load PL2 Actual machining load TL Tool W Workpiece

Claims

A machining system that executes a machining program in a machine tool and performs machining on a workpiece using a tool, the machine tool having a machine that performs actual machining on a workpiece based on the machining program, a control device that controls the machine, and a detection unit that detects an actual machining load generated on the machine corresponding to motion steps into which the machining program is subdivided, and stores the detected load in the control device; a simulation unit having a motion step generation unit that generates the motion steps, a machining load estimation unit that estimates a machining load on the machine device for each of the motion steps when the machining program is executed, a specific cutting resistance storage unit that stores a specific cutting resistance used for the estimation in association with tool information and workpiece information, and a specific cutting resistance identification unit that identifies a specific cutting resistance based on an actual machining load generated during actual machining; an identification region determination unit that determines whether the motion steps are suitable for detecting an actual machining load used to identify a specific cutting resistance based on a determination condition, and then determines a group of the motion steps that are continuous for a length equal to or greater than a pre-stored machining length threshold as an identification region suitable for actual machining to obtain an actual machining load for identifying a specific cutting resistance; a processing system including: 　 The machining system according to claim 1 , wherein the determination condition is a motion step in which a surface is again machined on a portion that has already been machined at least once. 　 The machining system according to claim 1 , wherein the determination condition is that the motion step is not a finishing motion step. 　 The machining system according to claim 1 , wherein the determination condition is that a motion step in which a change in machining amount from a previous motion step is smaller than a predetermined change threshold value.

2. The machining system according to claim 1, wherein the machine tool performs the actual machining a plurality of times, and the specific cutting resistance identifying unit identifies the specific cutting resistance based on the corresponding plurality of actual loads.

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