Processing system

Abstract

Provided is a machining system that improves the accuracy of specific cutting resistance identification by automatically determining a region for identifying specific cutting resistance, and thus enhances the accuracy of machining load estimation. 【Solution means】The machining system 10 includes a simulation unit 12 having a motion step generation unit 44, a machining load estimation unit 38 that estimates a machining load, a specific cutting resistance storage unit 46 that stores specific cutting resistance, and a specific cutting resistance identification unit 48 that identifies specific cutting resistance based on an actual machining load PL2, an identification region determination unit 14 that determines, based on a determination condition, whether a motion step is suitable for specific cutting resistance identification, and determines a continuous motion step group equal to or longer than a machining length threshold as an identification region for specific cutting resistance identification, a control device 20 that controls a machine device 18, and a detection unit 32 that detects an actual machining load PL2, and has a machine tool 16.

Description

Technical Field

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

Background Art

[0002] When machining a workpiece with a machine tool, it is necessary to monitor whether the generated machining load is appropriate. As a result of the monitoring, if the machining load is higher than the monitoring standard, it is determined that an abnormality has occurred, and the machine is stopped, or the machining load is reduced by lowering the machining conditions from the next time onward to stabilize the machining. On the other hand, if the machining load is lower than the determined monitoring standard, the machining time is shortened by improving the machining conditions from the next time onward. When monitoring machining, since it is preferable to determine the monitoring standard in advance prior to actual machining, conventionally, it is determined by estimation using the specific cutting resistance of the nominal value or the like. However, in actual machining, there are variations in the physical property values of the actual workpiece and differences in various specifications such as the clearance angle and rake angle of the tool used for machining, so in many cases, the machining load cannot be accurately estimated.

[0003] Citation Document 1 discloses an invention in which, based on the shape data of a test piece machined with a test program, the specific cutting resistance, which is the cutting force coefficient for each combination of tool and material, is estimated and made into a database. However, in such a processing method, a measurement process and a measuring device for acquiring the shape data of the test piece are separately required, so the man-hours and costs increase.

[0004] Also, in order to make the accuracy of identifying the specific cutting resistance closer to the actual situation, it is preferable that the machining load of the actual machining used for identifying the specific cutting resistance is stable. For this reason, although it is necessary to perform machining in a part (area) where the machining load is less likely to vary, there is no clear standard or technique for realizing a determination regarding which areas are suitable for identification and how to determine the suitable areas.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2022-087704 [Summary of the Invention] [Problems to be Solved by the Invention]

[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 specific cutting resistance by automatically determining a region for identifying specific cutting resistance, and thereby enhances the accuracy of estimating machining load. [Means for Solving the Problems]

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

[0008] According to a machining system according to one aspect of the present invention, a simulation unit of the machining system includes a motion step generation unit and a machining load estimation unit, and can generate motion steps obtained by subdividing a machining program and estimate an estimated machining load generated in a machine device of a machine tool for each motion step. Further, the machine tool of the machining system includes a control device that controls the machine device and a detection unit. The detection unit can detect an actual machining load generated in the machine device corresponding to a motion step group that is a set of motion steps and store it in the control device. In addition, an identification region determination unit of the machining system is configured to determine, based on a determination condition, whether a motion step is suitable for detecting an actual machining load used for identification of specific cutting resistance. Therefore, in a motion step group that is a set of motion steps determined to be identifiable based on the determination condition, a motion step group that is continuous and equal to or longer than a pre-stored machining length threshold value can be determined as an identification region suitable for actual machining for obtaining an actual machining load for identification of specific cutting resistance. Thereby, by automatically determining a region for identification of specific cutting resistance, the accuracy of identification of specific cutting resistance can be improved, and the accuracy of estimation of machining load can be enhanced.

Brief Description of Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Best Mode for Carrying Out the Invention

[0010] Hereinafter, a processing system according to an embodiment will be described with reference to the accompanying drawings. The same or corresponding elements are denoted by the same reference numerals, and redundant descriptions are omitted. For ease of understanding, the scale of the drawings may be changed for the description.

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

[0012] The machine tool 16 includes a machine device 18 that performs actual machining on a 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 erected on the upper surface of the bed 22. On the upper surface of the bed 22, a table 28 for fixing the workpiece W, which is the object to be machined, by a fixture (not shown) is arranged. The table 28 is configured to be movable on the bed 22 via a guide surface.

[0013] Machine coordinates with a predetermined position as the origin are preset in the machine device 18, and include an X-axis, a Y-axis, and a Z-axis as linear motion axes orthogonal to each other. Here, the Z-axis extends along the horizontal direction (the left-right direction of the paper). Also, the X-axis and the Y-axis are set on a plane perpendicular to the Z-axis, that is, on a vertical plane. In the machine device 18, the column 24 is configured to move along the X-axis direction (the direction perpendicular to the paper). Also, a saddle (not shown) is arranged on the front surface of the column 24 and is configured to be movable along the Y-axis direction (the up-down direction of the paper).

[0014] A spindle head (not shown) is arranged on the front surface of the saddle of the machine device 18, and a spindle 26 configured to be rotatable around an axis parallel to the Z-axis is attached to the tip side of the spindle head. A tool TL for machining the workpiece W while rotating together with the spindle 26 is detachably attached to the spindle 26. The machine device 18 is configured such that the spindle 26 for attaching the tool TL and the table 28 for arranging the workpiece W are relatively movable along the X-axis, the Y-axis, and the Z-axis.

[0015] The machine device 18 also has a tool changer 30 in order to perform various types of machining according to the machining purpose, and the tool changer 30 is configured to be able to exchange the tool TL attached to the spindle 26. Further, the machine device 18 includes a detection unit 32 configured to calculate (detect) an actual machining load PL2 from the loads generated in the motor (not shown) that drives the spindle 26 and the motors that drive the linear motion mechanism and the rotation mechanism (not shown) that relatively move the spindle and the table.

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

[0017] The simulation unit 12 performs a simulation of the machining program. For this purpose, the simulation unit 12 has an interference check unit 36 and a motion step generation unit 44. The motion step generation unit 44 generates motion steps obtained by subdividing the content of the machining program. FIG. 2 shows an example of a machining program (program number: O3001). Here, motion steps are generated each time the linear movement distance in the machining program changes by a certain amount. Note that, in the following description, it is assumed that motion steps are generated based on the linear movement distance, but it is not limited thereto. For example, they may be generated based on the elapsed time in the simulation.

[0018] FIG. 3 shows an example of a data file that records motion steps (columns DF0 to DF7 in FIG. 3) generated along a machining program, machining loads (columns DF8 and DF9 in FIG. 3), and determination results based on determination 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. In the data file, for each subdivided motion step (for each serial number in column DF0 in FIG. 3), a program number (column DF1 in FIG. 3), a corresponding sequence number in the machining program (column DF2 in FIG. 3), a tool number of the tool TL used for machining (column DF3 in FIG. 3), and the material of the workpiece W being machined (column DF4 in FIG. 3) are recorded. Further, 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 that linearly moves based on the machining program are recorded in the data file. Here, as an example, motion steps are generated every 0.2 mm of linear movement distance.

[0019] The simulation unit 12 further includes a machining load estimation unit 38 and a specific cutting resistance storage unit 46, and uses these to estimate the estimated machining load PL1 simultaneously with the generation of the motion step. When estimating the machining load as the estimated machining load PL1, the machining load estimation unit 38 estimates the estimated machining load PL1 for each motion step based on the specific cutting resistance stored in the specific cutting resistance storage unit 46 and the cutting area of the tool TL calculated by the interference confirmation unit 36. FIG. 4 shows an example of the specific cutting resistance stored in the specific cutting resistance storage unit 46. Here, the specific cutting resistance is stored for each workpiece W and the workpiece W to be machined, and the corresponding specific cutting resistance is used for the estimation of the estimated machining load PL1. Here, although the tools T1 and T3 have a record of identifying the specific cutting resistance for FC250, since the tool T2 has no record of identifying the specific cutting resistance for FC250, the nominal value kc is used for the specific cutting resistance of the tool T2 with respect to FC250. That is, the identification of the specific cutting resistance is required for the tool T2. The estimated machining load PL1 estimated in this way is recorded in the data file (column DF8 in FIG. 3). Here, the specific cutting resistance is described as a value defined for each combination of the materials 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, for example, a plurality of other parameters.

[0020] FIG. 5 shows an example of interference information. The interference confirmation unit 36 generates interference information (CWE: Cutter-Workpiece Engagement) between the tool TL and the workpiece W based on the machining program and the model information in accordance with the generation of the motion step. Based on this interference information, the interference confirmation unit 36 stores (records) the axial cutting (column CW1 in FIG. 5) and the radial cutting (column CW2 in FIG. 5) of the tool TL in each motion step (the serial number in column CW0 in FIG. 5), and is configured to calculate the cutting area in each motion step from these pieces of information. Although the interference in this embodiment is very simple, in an example where the interference is complex, such as when machining an inclined wall portion with a square end mill where the radial cutting amount varies depending on the axial position of the tool, the radial cutting amount and the axial cutting amount can also be calculated based on the engagement angle and the disengagement angle at each tool axial position. Further, the interference confirmation unit 36 can also confirm interference such as an unintentional collision between the workpiece W, the tool TL, the machine device 18, etc., separately from the interference as cutting.

[0021] The simulation unit 12 sets upper and lower limits based on the estimated machining load PL1 and determines the monitoring band BM. The monitoring band BM calculates the upper limit value UV and the lower limit value LV of the monitoring band BM by adding and subtracting a predetermined ratio (for example, ±5%) preset and stored with respect to the estimated machining load PL1. The difference between this upper limit value UV and the lower limit value LV is the bandwidth of the monitoring band BM.

[0022] The control device 20 includes a monitoring unit 52, and can monitor the actual machining in the machine device 18 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 of the control device 20 is greater than the upper limit value UV or less than the lower limit value LV, the control device 20 determines that an abnormality has occurred in the machine device 18 because it exceeds the upper limit of the monitoring band BM or falls below the lower limit value, and is configured to stop the machine device 18.

[0023] The simulation unit 12 has an identification region determination unit 14. The identification region determination unit 14 is configured to determine whether each motion step is suitable for detecting the machining load used for the identification of the specific cutting resistance based on the determination conditions, and then determine the motion steps 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 whether each motion step is suitable for detecting the machining load used for the identification of the specific cutting resistance based on the determination conditions, and then determines the identification region. The simulation unit 12 inputs the machining program (Figure 2) and the data file (Figure 3) into the control device 20 of the machine tool 16. The control device 20 operates the mechanical device 18 based on the input machining program and data file to perform the actual machining of the workpiece W.

[0024] Three determination conditions are set here in the fixed area determination unit 14. The first determination condition is whether to machine the surface of the material in each motion step. The surface of the material means a part that has never been machined. For example, in a cast workpiece W, it means the black skin part. Since the shape and hardness of the black skin part are unstable, the machining load is also unstable, so it is not suitable for the area where the machining load used for identifying the specific cutting resistance is detected. When generating interference information (Fig. 5) in accordance with the generation of motion steps, the simulation unit 12 can update the shape of the workpiece model according to the machining, for example, and include information on whether each motion step machines the surface of the material in the interference information. Therefore, referring to the interference information, if the current motion step is not machining the surface of the material, that is, it is a part where at least one surface machining has already been performed, and surface machining is to be performed again in the said motion step, it is determined that it is suitable for detecting the machining load used for identification. This determination condition is set as the first determination condition. This determination may be performed simultaneously when each motion step is generated. In the example of the data file according to the present embodiment shown in Fig. 3, the motion step group (the part surrounded by a square in Fig. 3) at the sequence number N1203 of the tool T2 for which identification is to be performed is a process that is performed after machining the surface of the material at the sequence number N1103 of the tool T1, and since it does not correspond to the machining of the surface of the material, it is determined that it is suitable for detecting the machining load used for identification. Therefore, an × mark indicating that it is not suitable for detecting the machining load used for identification is recorded at the location corresponding to the sequence number N1103 in the column DF10 in Fig. 3, and a ○ mark indicating that it is suitable for detecting the machining load used for identification is recorded at the location corresponding to the sequence number N1203 in the column DF10.

[0025] The second determination condition is whether or not to perform finishing in each motion step. In actual machining for obtaining the machining load for identifying specific cutting machining, the cutting feed rate may be varied at a certain machining length to obtain the actual machining load PL2, and the surface finish of the machining does not become constant. As a result, there may be a case where the workpiece W has to be discarded when the surface finish does not meet the required accuracy. Therefore, after all the motion steps are generated, it is determined based on coordinate information, interference information, etc. whether each motion step is a finishing process, and if it is not a finishing process, it is determined that it is suitable for detecting the machining load used for identification. This determination condition is set as the second determination condition. In the example of the data file according to the present embodiment shown in FIG. 3, the motion step group (the portion surrounded by the square in FIG. 3) at the sequence number N1203 of the tool T2 for which identification is to be performed is semi-finishing, and then finishing is performed at the sequence number N1303 of the tool T3. Therefore, since the motion step group at the sequence number N1203 does not correspond to the finishing process, it is determined that it is suitable for detecting the machining load used for identification. Thus, in the example of the data file in FIG. 3, in the column DF11 of the data file in FIG. 3 showing the second determination condition, for the sequence number N1203, a ○ mark indicating that it is suitable for detecting the machining load used for identification is recorded, and for the sequence number N1303, a × mark indicating that it is not suitable for detecting the machining load used for identification is recorded.

[0026] The third determination condition is whether the machining amount for each motion step is stable. Here, the machining amount, for example, in the case of surface machining by a cutting tool, means the cutting depth in the tool axis direction and the cutting depth in the tool radius direction. The machining amount can be obtained from the interference information generated in accordance with the generation of the motion step. Further, the difference in the machining amount between the motion step to be determined and the immediately preceding motion step is calculated from the interference information, and the variation in the machining amount can be grasped. Therefore, when the variation in the machining amount is smaller than the variation threshold determined and memorized in advance, preferably zero, it is determined that the machining amount is stable and suitable for detecting the machining load used for identification. This determination condition is set as the third determination condition. In the example of the data file according to this embodiment shown in FIG. 3, the motion step at the sequence number N1203 of the tool T2 for which identification is to be performed is a finish machining operation in which, after machining at the sequence number N1103 of the tool T1, further cutting is performed in the Z direction (tool axis direction) and movement is made only in the Y direction. FIG. 6 schematically shows a machining diagram at the sequence number N1203. Since the cutting depth in the tool axis direction and the cutting depth in the tool radius direction are constant from Y30.0 to 44.0 within N1203, it can be determined that the variation in the machining amount is zero and stable. Therefore, in the column DF12 in FIG. 3 showing the third determination condition, for the range from Y30.0 to 31.0 within the sequence number N1203, an ○ mark indicating suitability for detecting the machining load used for identification is recorded. Although omitted in FIG. 3, the ○ mark is similarly recorded for the motion steps from the Y coordinate 31.0 to Y44.0. Here, it is emphasized that the machining amount is determined based on the stability of both the cutting depths in the radial direction and the axial direction. This is because even if the machining amounts in the radial direction and the axial direction vary, there are cases where the chip discharge amount per unit time is the same, but in this case, since the acting direction of the machining load varies, as a result, the actual machining load PL2 is not stable.

[0027] When the determination based on the three determination conditions is completed, the identification area determination unit 14 extracts, as a motion step group, motion steps that are continuous for a predetermined machining length threshold or more among the motion steps that satisfy all of the three determination conditions, and determines the extracted motion step group as the identification area (the portion surrounded by the square in FIG. 3). For the identification of the specific cutting resistance, since the actual machining load PL2 at a machining length of a certain level or more is required, it is necessary to set a machining length threshold for the determination of the identification area based on this. In the example shown in FIG. 3, the machining length threshold is set to 10 mm. In the data file of this embodiment, for the sequence number N1203 of the tool T2 to be identified, as shown in FIG. 6, the spindle and the tool move from Y20.0 to Y50.0 to perform machining. Among these, the machining from Y30.0 to Y44.0 satisfies all of the above-mentioned three determination conditions, and the machining length is also 14 mm. Therefore, the motion step group in this machining path can be determined as the identification area. When there are a plurality of motion step groups determined as the identification area, the identification area determination unit 14 may automatically determine the motion step group with the longest machining length as the identification area. Further, the identification area determination unit 14 may notify the operator that there are a plurality of motion step groups determined as the identification area, and prompt the operator to determine the motion step group for performing the actual machining for identification from the plurality of motion step groups.

[0028] Further, according to the processing system 10 according to the present embodiment, the identification region determination unit 14 is configured to be able to identify the specific cutting resistance based on a plurality of actual processing loads PL2 detected in a plurality of actual processings. This is because even in a stable region, if sudden tool breakage or the like occurs during actual processing, noise caused by this will occur in the data of the actual processing load PL2. Therefore, the control device 20 of the machine tool 16 stores a predetermined number of times, executes the processing program the predetermined number of times, and acquires a plurality of actual processing loads PL2. Further, according to the processing system 10, it is configured such that a plurality of actual processing loads PL2 can be visualized in time series on a display unit (not shown). Therefore, after the operator checks the presence or absence of noise and manually removes the noise, the plurality of actual processing loads PL2 can be averaged, recorded in a data file, and input to the specific cutting resistance identification unit 48. Also, when the control device 20 of the machine tool 16 can determine that the difference between the plurality of actual processing loads PL2 is smaller than a predetermined processing load threshold value and there is no noise, the noise removal process can be omitted without going through the operator, the plurality of actual processing loads PL2 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. Further, 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 not exceeding the allowable machining load. Also, in either case where the estimated machining load PL1 exceeds or is below the allowable machining load, the machining program can be returned to the CAM system 34 or the operator without automatic optimization. Since 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, when the interference confirmation unit 36 confirms interference as an unintended collision of the workpiece W, the tool TL, and the machine device 18 when the machining program is executed, the simulation unit 12 can return to the program generation process, that is, the CAM system 34 or the operator.

[0030] Through the explanation of the machining process of the workpiece W using the flowchart of the machining system 10 shown in FIG. 7, the operation and effect of the machining system 10 according to the present embodiment will be described below.

[0031] First, the process proceeds to step S10 to start the machining process, and then proceeds 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 the model data to the simulation unit 12.

[0032] Furthermore, 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 whether there is an identification record stored in the data file and the specific cutting resistance storage unit 46, that is, whether there is a past identification record of the specific cutting resistance corresponding to the tool TL used in the motion step and the workpiece W to be machined. If there is an identification record, the process proceeds to step S60, where the simulation unit 12 estimates the estimated machining load PL1 for the motion step using the specific cutting resistance with an identification record. On the other hand, if there is no identification record, the process proceeds to step S80, where the simulation unit 12 estimates the estimated machining load PL1 for the motion step using the nominal specific cutting resistance without an identification record. After estimating the estimated machining load PL1, the process proceeds to step S70, where it is checked whether the generation of all motion steps is completed. The simulation unit 12 repeats steps S40 to S80 until the generation of all motion steps is 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] After determining the identification area, the process proceeds to step S100, where the simulation unit 12 inputs a data file including the optimized machining program, motion step information, identification area, and 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, where the mechanical 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 area is stored in the machining load storage unit 54.

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

[0037] According to the machining system 10 according to the present embodiment, the simulation unit 12 of the machining system 10 includes a motion step generation unit 44 and a machining load estimation unit 38, and can generate motion steps obtained by subdividing a machining program and estimate the machining load generated in the machine device 18 of the machine tool 16 for each motion step. Further, the machine tool 16 of the machining system 10 includes a control device 20 that controls the machine device 18 and a detection unit 32. The detection unit 32 can detect the actual machining load PL2 generated in the machine device 18 corresponding to a motion step group that is a set of motion steps and store it in the control device 20. Therefore, the machining system 10 can set a monitoring band BM for 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] Also, according to the processing system 10 according to the present embodiment, the identification area determination unit 14 of the processing system 10 is configured to determine whether a motion step is suitable for detecting the actual processing load PL2 used for identifying the specific cutting resistance based on three determination conditions. Therefore, among the motion step groups that are a set of motion steps determined to be identifiable based on these determination conditions, a continuous motion step group with a processing length equal to or greater than a pre-stored processing length threshold can be determined as an identification area for obtaining the actual processing load PL2 for identifying the specific cutting resistance. As a result, the area for identifying the specific cutting resistance can be automatically determined, improving the accuracy of identifying the specific cutting resistance and enhancing the accuracy of estimating the estimated processing load PL1. That is, the monitoring unit 52 can accurately monitor the actual processing load PL2.

[0039] Furthermore, according to the processing system 10 according to the present embodiment, when performing actual processing on the motion step group determined as the identification area, the actual processing load PL2 can be detected by the detection unit 32 corresponding to the motion step and stored in the processing load storage 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 speed in the motion step group to increase the variation of the actual processing load PL2 to be obtained. Specifically, taking the cutting feed speed commanded by the NC program as 100%, the cutting feed speed can be varied using the override function of the machine tool 16 to three types, for example, 50%, 75%, and 100% within the range of 100% or less so as not to exceed the allowable load of the machine tool 16. After the actual processing is completed, the control device 20 of the machine tool 16 can add the actual processing load PL2 to the data file and input it to the simulation unit 12.

[0040] Also, according to the processing system 10 according to the present embodiment, the specific cutting resistance identification unit 48 of the simulation unit 12 identifies the specific cutting resistance based on the actual processing load PL2, and can also store it in the specific cutting resistance storage unit 46 together with information indicating that there is an identification record. Therefore, in subsequent processing steps, for the estimation of the estimated processing load PL1 with the same combination of tool TL and workpiece W (in this embodiment, the combination of tool T2 and workpiece FC250), the specific cutting resistance identified by the specific cutting resistance identification unit 48 can be used.

[0041] Furthermore, according to the processing system 10 according to the present embodiment, the identification area determination unit 14 is configured to be able to identify the specific cutting resistance based on a plurality of actual processing loads PL2 detected in multiple actual machining operations. Also, the display unit is configured to be able to visualize a plurality of actual processing loads PL2 in time series. After the operator checks the presence or absence of noise and manually removes the noise, the plurality of actual processing loads PL2 can be averaged, recorded in a data file, and input to the specific cutting resistance identification unit 48. Therefore, even when noise occurs due to sudden 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 processing system 10 according to the present embodiment can improve the accuracy of identifying the specific cutting resistance by automatically determining the area for identifying the specific cutting resistance, and thus can improve the accuracy of estimating the estimated processing load PL1, and can accurately monitor the actual processing load PL2 by the monitoring unit 52.

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

[0044] Although the embodiments of the processing system 10 have been described above, the present invention is not limited to the above embodiments. For example, instead of a vertical machining center with a horizontal spindle orientation, a horizontal machining center with a vertical spindle orientation may be used. In addition to the above, those skilled in the art can understand that various modifications of the above embodiments are possible.

Explanation of Reference Numerals

[0045] 10 Processing system 12 Simulation unit 14 Identification area determination unit 16 Machine tool 18 Mechanical 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 memory unit 48 Specific cutting resistance identification unit 52 Monitoring unit 54 Machining load memory unit PL1 Estimated machining load PL2 Actual machining load TL Tool W Workpiece

Claims

1. A machining system that executes a machining program in a machine tool and performs machining on a workpiece using a tool, comprising: a machine device that performs actual machining on a workpiece based on the machining program; a control device that controls the machine device; and a detection unit that detects an actual machining load generated in the machine device corresponding to a motion step obtained by subdividing the machining program and stores the detected load in the control device; a motion step generation unit that generates the motion steps; a machining load estimation unit that estimates the machining load of the machine device for each of the motion steps when the machining program is executed; a specific cutting resistance storage unit that stores the specific cutting resistance 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; an identification area determination unit that determines, based on a determination condition, whether the motion step is suitable for detecting the actual machining load used for identifying the specific cutting resistance, and determines a group of consecutive motion steps having a machining length equal to or greater than a pre-stored machining length threshold as an identification area suitable for actual machining for obtaining the actual machining load for identifying the specific cutting resistance; A machining system comprising the above components.

2. The machining system according to claim 1, wherein the determination condition is that the motion step is a motion step for performing surface machining again on a part that has already undergone surface machining at least once.

3. The machining system according to claim 1, wherein the determination condition is that the motion step is not a finishing machining step.

4. The machining system according to claim 1, wherein the determination condition is that the machining amount variation from the immediately preceding motion step is smaller than a predetermined variation threshold.

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

Images