Machining system

Abstract

Provided is a machining system that makes it possible to specify adjustment information on the basis of an actual machining load and precisely monitor subsequent machining on the basis of an adjusted machining load adjusted in a simple and precise manner using the adjustment information.　The present invention includes: a simulation unit (12) having a motion step generation unit (44), a machining load estimation unit (38), and a specific cutting resistance storage unit (46) in which specific cutting resistance is stored in association with workpiece information; a machine tool (16) having an adjustment unit (14) that includes an adjustment information storage unit (48) for storing adjustment information and adjusts a machining load estimated using the adjustment information, a control device (20) for monitoring the machining load and controlling a machine device (18) whereby actual machining is performed on a workpiece (W), and a detection unit (32) for detecting the actual machining load; and an adjustment information specifying unit (54) that specifies the adjustment information on the basis of the estimated machining load and the actual machining load and stores the adjustment information in the adjustment information storage unit (48) in association with tool information and workpiece information.

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 a computer and a processing method for estimating specific cutting resistance, which is a cutting force coefficient for each combination of tool and material, based on shape data of a test piece machined by a test program, and for improving the accuracy of the estimation. However, this processing method requires a separate measurement process and measuring device for acquiring shape data of the test piece, which increases the number of work steps and costs.

[0004] Furthermore, the specific cutting resistance is a nominal value, and in order to make the accuracy of estimating the machining load closer to the actual value, it is necessary to actually prepare a machine tool, a tool, and a workpiece, perform actual machining, and identify the specific cutting resistance based on the actual machining load data and CWE (Cutter-Workpiece Engagement) information generated at that time. However, such identification requires a very high level of calculation capability, and it also becomes necessary to provide the machine tool with a device for directly measuring the machining load, etc., which increases the number of work steps and costs.

[0005] Furthermore, in general commercially available software for providing machining simulations, software vendors generally keep the database area of ​​specific cutting resistance as a black box, as their own know-how. Therefore, even if manufacturers or users of the machine tools that actually perform machining estimate the specific cutting resistance based on the actual machining, they cannot access the database area of ​​specific cutting resistance, and therefore the current situation is that the estimated results of the specific cutting resistance cannot be reflected.

[0006] Japanese Patent Application Laid-Open No. 2022-087704

[0007] In view of the above circumstances, the present invention aims to provide a machining system that identifies adjustment information for adjusting an estimated machining load based on the actual machining load when actual machining is performed with a machine tool, and that can accurately monitor subsequent machining based on the adjusted machining load that is simply and accurately adjusted using the adjustment information.

[0008] 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; 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 load in the control device; and a monitoring unit that monitors the actual machining load; a motion step generation unit that generates motion steps; a simulation unit that has a machining load estimation unit that estimates the machining load of the machine for each motion step when the machining program is executed as an estimated machining load; and a specific cutting resistance storage unit that stores a specific cutting resistance used for the estimation in correspondence with workpiece information; an adjustment unit that has an adjustment information storage unit that stores adjustment information in correspondence with the tool information and the workpiece information and adjusts the estimated machining load using the adjustment information; and an adjustment information identification unit that identifies adjustment information to be used to adjust the estimated machining load based on a comparison between the estimated estimated machining load and the actual machining load, and stores the adjustment information in the adjustment information storage unit in correspondence with the tool information and the workpiece information when the actual machining load occurs.

[0009] 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, and generates motion steps by dividing a machining program and estimates an estimated machining load of a machine tool for each motion step. The adjustment unit of the machining system includes an adjustment information storage unit that stores adjustment information in association with tool information and workpiece information, and can adjust the estimated machining load using the adjustment information. The machine tool of the machining system includes a control device that controls the machine, a detection unit, and a monitoring unit, and the detection unit can detect an actual machining load occurring on the machine corresponding to the motion steps and store the detected load in the control device. The adjustment information determination unit of the machining system can determine adjustment information to be used for adjusting the estimated machining load based on a comparison between the estimated estimated machining load and the actual machining load, and can store the adjustment information in the adjustment information storage unit in association with tool information and workpiece information when the actual machining load occurs. Therefore, the adjustment information to be used for adjusting the estimated machining load can be determined based on the actual machining load observed when the machine tool performs actual machining. This enables simple and accurate adjustment of the estimated machining load using the adjustment information, and subsequent machining can be monitored accurately based on the adjusted machining load.

[0010] 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 adjustment information according to this embodiment. FIG. 6 shows an example of a change in machining load over time. FIG. 7 shows a flowchart of the machining system according to this embodiment.

[0011] 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.

[0012] 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 PL3, which is a 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 (see FIG. 6) of the machining load based on the estimated machining load PL1 and monitors whether the detected actual machining load PL3 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 for actually machining the workpiece W (hereinafter referred to as "actual machining"). The simulation unit 12 is electrically connected to the machine tool 16 and includes an adjustment unit 14 for adjusting the estimated machining load PL. 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.

[0013] 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.

[0014] 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).

[0015] 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.

[0016] 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) an actual machining load PL3 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.

[0017] 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. Information about a jig (not shown) for mounting the workpiece W may be further input as information necessary for machining, in order to perform detailed interference checks between the tool TL and the workpiece W. After generating the machining program, the CAM system 34 transmits (inputs) the program to the simulation unit 12 together with model data about the workpiece W, etc. Alternatively, the operator may directly create a machining program based on their experience and input it to the simulation unit 12 without using the CAM system 34.

[0018] 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.

[0019] FIG. 3 shows an example of a data file recording motion steps (columns DF0 to DF7 in FIG. 3 ) and various machining loads (columns DF8 to DF10 in FIG. 3 ) generated in accordance with a machining program. The simulation unit 12 records the generated motion steps in the data file. 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 for 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 every linear movement distance of 0.2 mm.

[0020] Furthermore, the interference checking unit 36 ​​generates, based on the machining program and model information, interference information (CWE: Cutter-Workpiece Engagement) between the tool TL and the workpiece W in accordance with the generation of the motion steps. Based on this interference information, the cutting area of ​​the tool TL in each motion step can be calculated.

[0021] 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 machining load (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 the specific cutting resistance corresponding to the workpiece W to be machined is used to estimate the estimated machining load PL1. In this manner, the estimated machining load PL1 is recorded in a data file (column DF8 in FIG. 3 ) corresponding to each motion step. Here, the specific cutting resistance is described as a value defined for each material of the workpiece W, as shown in FIG. 4 . However, the specific cutting resistance may be further defined for each of multiple parameters, such as for the tool.

[0022] When a motion step is generated and the machining load estimating unit 38 estimates the estimated machining load PL1, the adjusting unit 14 adjusts the estimated machining information PL1. The adjusting unit 14 has an internal adjustment information storage unit 48 in which adjustment information a for each combination of a tool TL and a workpiece W in the generated motion step is stored (recorded). Here, the tool number of the tool TL and the workpiece material of the workpiece W are stored as information corresponding to the adjustment information a. FIG. 5 shows an example of adjustment information a stored in the adjustment information storage unit 48. The adjustment information a ("***" in FIG. 5) is recorded for each tool TL (tool number) and workpiece W. For combinations of a tool TL and a workpiece W for which no adjustment information a is specified, the absence of adjustment information a ("- (none)" in FIG. 5) is recorded. The adjusting unit 14 refers to whether or not adjustment information a corresponding to the combination of a tool TL and a workpiece W used in actual machining is stored. If adjustment information a is stored, the adjusting unit 14 adjusts the estimated machining load PL1 based on the adjustment information a. Here, the adjusted machining load PL2 is calculated by multiplying the estimated machining load PL1 by the adjustment information a. The calculated adjusted machining load PL2 is recorded in the data file (column DF9 in FIG. 3), and the estimated machining load PL1 in the motion step in which the adjusted machining load PL2 was recorded is deleted. Note that if the adjustment information a is not stored, no adjustment is made in that motion step, and the estimated machining load PL1 remains recorded in the data file.

[0023] The adjustment information a may be, for example, a coefficient. Specifically, by comparing the estimated machining load PL1 with the actual machining load in time series and multiplying the estimated machining load PL1 in the time series of actual machining, a coefficient that can approximate the greatest common denominator of the actual machining load can be set as the adjustment information a.

[0024] Here, the adjustment unit 14 is configured in a separate area within the simulation unit 12 from the machining load estimation unit 38 and the specific cutting resistance storage unit 46. This allows the machining system 10 to be configured while keeping the calculation models and know-how of the software vendor and the machine tool manufacturer confidential.

[0025] 6 shows the adjusted processing load PL2 calculated for each motion step. The adjustment unit 14 sets upper and lower limits based on the adjusted processing load PL2 and determines 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 adjusted processing load PL2. The difference between the upper limit UV and the lower limit LV is the bandwidth of the monitoring band BM. The monitoring band may be set wider as long as it does not reach a load that is allowable due to the characteristics of the machine 18.

[0026] After generating the motion steps and adjusting the machining load PL2, the simulation unit 12 inputs the machining program (FIG. 2) and data file (FIG. 3) to the control device 20 of the machine tool 16. The control device 20 operates the machine 18 based on the input machining program to perform actual machining of the workpiece W. The control device 20 is equipped with a monitoring unit 52, which can monitor actual machining by checking whether the actual machining load PL3 detected by the detection unit 32 is within the monitoring band BM. The control device 20 also has a machining load memory unit 50, and the actual machining load PL3 detected by the detection unit 32 during actual machining is stored in the machining load memory unit 50 as a past machining load PL4. The actual machining load PL3 is also recorded in a data file (column DF10 in FIG. 3).

[0027] Here, if the estimated machining load PL1 is estimated using a nominal value kc for the specific cutting resistance, the actual machining load PL3 may fall outside the monitoring band BM set based on the estimated machining load PL1, resulting in ineffective monitoring. For example, depending on the manufacturing method used to cast the workpiece W, variations in the physical properties of the actual workpiece W may occur, and the specific cutting resistance value of the workpiece W from a particular manufacturer may not necessarily match the nominal value kc. Furthermore, the actual machining load PL3 may also vary depending on various cutting edge shapes, such as the cutting edge treatment, rake angle, and clearance angle, of the tool TL used for machining. Thus, various factors may prevent the estimated machining load PL1 from being accurately estimated. That is, even if the actual machining load PL3 is an appropriate machining load, monitoring may fail because it is greater than the upper limit UV or smaller than the lower limit LV of the monitoring band BM based on the inaccurately estimated estimated machining load PL1. If the control device 20 is configured to determine that an abnormality has occurred in the machine device 18 and stop the machine device 18, if the actual processing load PL3 monitored by the monitoring unit 52 is greater than the upper limit value UV or less than the lower limit value LV, the machine device 18 will stop unnecessarily, resulting in a decrease in production efficiency.

[0028] To prevent such problems from occurring, the machining system 10 according to this embodiment includes an adjustment information specifying unit 54 in the control device 20, which can specify adjustment information a for comparing the adjusted machining load PL2 with the actual machining load PL3. Here, the adjustment information a is specified so that the adjusted machining load PL2, calculated by multiplying the estimated machining load PL1 by the adjustment information a, can be compared with the actual machining load PL3. The specified adjustment information a is stored in the adjustment information storage unit 48 along with information on the tool TL and workpiece W. When no adjustment information a exists before actual machining, such as in the motion step corresponding to sequence number N1303 in the data file of FIG. 3, the adjustment information a is specified so that the actual machining load PL3 (the boxed portion in column DF10 in FIG. 3) can be adjusted with the adjusted machining load PL2 calculated by multiplying the estimated machining load PL1 by the adjustment information a.

[0029] Although it is preferable to detect the actual machining load PL3 for identifying the adjustment information a when no irregularities, such as casting defects in the workpiece W, chip clogging, or breakage of the tool TL, occur, these irregularities may actually occur. In this case, the actual machining load PL3 may fluctuate depending on the degree of the irregularity. For example, the actual machining load PL increases when chip clogging occurs, and decreases when the machining allowance is reduced due to a casting defect in the workpiece W or when tool breakage occurs and the tool TL and the workpiece W are not in contact. In order to suppress the influence of such irregularities, the adjustment information identification unit 54 of the machining system 10 is configured to identify the adjustment information a after performing actual machining multiple times. This allows for the removal of noise when irregularities occur, thereby enabling the adjustment information a to be identified with high accuracy.

[0030] The control device 20 of the machine tool 16 is configured to automatically remove noise from the corresponding multiple actual machining loads PL3 after the machine device 18 performs actual machining multiple times. Furthermore, the multiple actual machining loads PL3 can be displayed as a time-series graph on the display device (not shown) of the machine tool 16, allowing the operator to visually determine and remove noise. After removing noise in this manner, the adjustment information a can be determined from the average value of the multiple actual machining loads PL3. Furthermore, if multiple actual machining operations are performed without irregularities, i.e., if the machine tool control device determines that stable actual machining loads PL3 have been obtained, the noise removal process may be omitted, and the adjustment information a may be determined from the average value of the multiple actual machining loads PL3. Furthermore, if the operator visually determines that irregularities continue to occur during multiple actual machining operations, it can be determined that the actual machining is being performed under undesirable conditions, and the data on the actual machining load PL3 corresponding to the multiple actual machining operations up to that point can be discarded, and the elements of the actual machining, such as the machining conditions, tool TL, jig, and the state of the mechanical device 18, can be inspected and reviewed, before instructing the machine tool 16 to perform multiple actual machining operations again.

[0031] The simulation unit 12 may also include an optimization unit 40 and a machine information storage unit 42. When the estimated machining load PL1 or the adjusted machining load PL2 exceeds the allowable machining load stored in the machine information storage unit 42, 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 or the adjusted machining load PL2 is below the allowable machining load, the optimization unit 40 is configured to speed up the machining speed in the machining program within a range that does not exceed the allowable machining load. Furthermore, in either case where the estimated machining load PL1 exceeds or falls below the allowable machining load, the machining program can be returned to the CAM system 34 or an operator without being automatically optimized. Since these optimizations are performed based on the estimated machining load PL1 or the adjusted machining load PL2, accurately adjusting the machining load is also important in optimization. Furthermore, if the simulation unit 12 confirms, via the interference confirmation unit 36, interference between the workpiece W, tool TL, and machine device 18 when the machining program is executed, it can return the program to the program generation process, i.e., to the CAM system 34 or the operator.

[0032] 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.

[0033] 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.

[0034] Next, the process proceeds to step S40, where the motion step generator 44 generates a motion step for each step based on the machining program. At the same time, the machining load estimator 38 estimates an estimated machining load PL1 using the specific cutting resistance stored in the specific cutting resistance memory 46. Next, the process proceeds to step S50, where it is confirmed whether adjustment information a corresponding to the tool TL used in the motion step and the workpiece W to be actually machined exists in the adjustment information memory 48. If adjustment information a exists, the process proceeds to step S60, where the estimated machining load PL1 is multiplied by the adjustment information a to adjust it to an adjusted machining load PL2, and the estimated machining load PL1 is deleted from the data file. Next, the process proceeds to step S70, where it is confirmed whether generation of all motion steps of the machining program has been completed. Thereafter, steps S40 to S70 are repeated until generation of all motion steps has been completed.

[0035] Furthermore, in step S50, if there is no adjustment information a, no adjustment is performed and the estimated machining load PL1 remains recorded. Next, the process proceeds to step S70 to check whether generation of all motion steps of the machining program has been completed. Thereafter, steps S40 to S70 are repeated until generation of all motion steps has been completed.

[0036] When generation of all motion steps is complete, the process proceeds to step S80, where the simulation unit 12 inputs the machining program and data file into the control device 20 of the machine tool 16. Then, the process proceeds to step S90, where the machine device 18 starts actual machining in accordance with the machining program based on a command from the control device 20. When actual machining starts, the process proceeds to step S100, where, when executing the machining program, the control device 20 checks whether a past machining load PL4 corresponding to the combination information of the n-th tool TL and workpiece W is stored in the machining load memory unit 50.

[0037] If the machining load memory unit 50 stores a past machining load PL4 corresponding to the combination information of the tool TL and workpiece W, the process proceeds to step S110. During machining of the nth tool TL, the monitoring unit 52 monitors the actual machining load PL3 based on the past machining load PL4 (case X in FIG. 7 ). Here, the machine tool 16 stores the actual machining load PL3 in the machining load memory unit 50 during actual machining, and can use this as the past machining load PL4 to monitor actual machining of the same combination of tool TL and workpiece W from the next time onward. By using the past machining load PL4, the reliability of the monitoring band BM can be increased compared to the monitoring band BM based on the estimated machining load PL1 and the adjusted machining load PL2, allowing for more accurate monitoring. Once the actual machining and monitoring of the nth tool TL is completed, the process proceeds to step S120, where it is confirmed whether machining using all tools TL has been completed. The flow between steps S100 and S120 is repeated until machining using all tools TL has been completed. When storing the past machining load PL4, the machining load storage unit 50 can also store the machining program number and the sequence number group in addition to the combination information of the tool TL and the workpiece W. The monitoring unit 52 can correctly refer to the past machining load PL4 for the actual machining load PL3.

[0038] Also, in step S100, if the past machining load PL4 corresponding to the combination information of the tool TL and the workpiece W for the nth tool TL is not stored in the machining load memory unit 50, the process proceeds to step S130.

[0039] In step S130, the process checks whether the estimated machining load PL1 for the nth tool TL in the machining program has been adjusted, i.e., whether the adjusted machining load PL2 has been recorded in the data file. If the adjusted machining load PL2 is stored in the adjustment information storage unit 48, the process proceeds to step S140. During actual machining using the nth tool TL, the monitoring unit 52 monitors the actual machining load PL3 based on the adjusted machining load PL2. At the same time, the control device 20 stores the actual machining load PL3 in the machining load storage unit 50 (case Y in FIG. 7). The adjusted machining load PL2 is adjusted based on adjustment information a determined based on the actual machining load PL3, and is therefore more reliable than the estimated machining load PL1, thereby improving the accuracy of machining monitoring. Furthermore, the actual machining load PL3 at this time is stored in the machining load storage unit 50 and can be used as the past machining load PL4 for machining monitoring in subsequent machining operations. After the actual machining load PL3 is stored in the machining load storage unit 50, the process proceeds to step S120 to check whether machining using all the tools TL has been completed. The flow between step S100 and step S120 is repeated until machining using all the tools TL has been completed.

[0040] This case Y may include a case where adjustment information a has been specified because machining has never been performed using the machine tool 16 before and therefore no past machining load PL4 has been stored, but machining has been performed using another machine tool 16 with the same combination of tool TL and workpiece W. Also, case Y may include a case where adjustment information a has been specified because a different shape has been machined using the machine tool 16 with the same combination of tool TL and workpiece W, but this is the first time machining has been performed using the input machining program.

[0041] If the adjusted machining load PL2 is not stored in the adjustment information storage unit 48, the process proceeds to step S150. During machining using the nth tool TL, the monitoring unit 52 monitors the actual machining load PL3 based on the estimated machining load PL1, and the machining load storage unit 50 stores the actual machining load PL3 (case Z in the figure). Therefore, the actual machining load PL3 stored in the machining load storage unit 50 can also be used to monitor machining as the past machining load PL4 in subsequent actual machining operations. The process then proceeds to step S160. The adjustment information identification unit 54 identifies adjustment information a based on the actual machining load PL3 and the estimated machining load PL1, and updates the adjustment information storage unit 48. Specifically, the adjustment information a is identified based on the difference between the estimated machining load PL1 and the actual machining load PL3, and is stored in the adjustment information storage unit 48 in association with the combination information of the tool TL and the workpiece W. The process then proceeds to step S120, where it is confirmed whether machining using all the tools TL has been completed. The flow between step S100 and step S120 is repeated until machining using all the tools TL is completed.

[0042] When the process proceeds to step S150, the control device 20 detects the passage of a predetermined time after the start of actual machining, determines provisional adjustment information a based on a comparison between the actual machining load PL3 acquired up to this elapsed time and the corresponding estimated machining load PL1, and calculates the adjusted machining load PL2 based on this provisional adjustment information a. In this case, after the passage of the predetermined time, monitoring can be performed based on the adjusted machining load PL2 calculated using the provisional adjustment information a. Note that detection of the passage of the predetermined time may be performed by the operator instead of the control device 20. The control device 20 is configured to acquire such provisional adjustment information a, and when the operator presses a provisional adjustment button displayed on the display unit (not shown) of the control device 20 during machining, the provisional adjustment information a can be determined based on the actual machining load PL3 acquired up to that point and the corresponding estimated machining load PL1.

[0043] In a machining system 10 according to one aspect of the present invention, the simulation unit 12 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. The adjustment unit 14 also has an adjustment information storage unit 48 that stores adjustment information a in association with tool information and workpiece information, and is able to adjust the estimated machining load PL1 using the adjustment information a to calculate an adjusted machining load PL2. Since the adjusted machining load PL2 is adjusted based on the adjustment information a determined based on the actual machining load PL3, it can be more reliable than the estimated machining load PL1, enabling machining to be monitored with improved accuracy.

[0044] Furthermore, according to the machining system 10 according to one aspect of the present invention, the machine tool 16 has a control device 20 that controls the mechanical device 18, a detection unit 32, and a monitoring unit 52, and the detection unit 32 can detect an actual machining load PL3 generated on the mechanical device 18 corresponding to a motion step and store it in the control device 20. Therefore, the actual machining load PL3 stored in the machining load storage unit 50 can be used for monitoring machining as a past machining load PL4 in the next and subsequent machining operations.

[0045] Furthermore, in the machining system 10 according to one aspect of the present invention, the adjustment information specifying unit 54 specifies adjustment information a to be used for adjusting the estimated machining load PL1 based on a comparison between the estimated machining load PL1 and the actual machining load PL3, and can store the adjustment information a in the adjustment information storage unit 48 in association with the tool information and workpiece information when the actual machining load PL3 occurred. Therefore, the adjustment information a to be used for adjusting the estimated machining load PL1 can be specified based on the actual machining load PL3 when actual machining is performed on the machine tool 16. This makes it possible to simply and accurately adjust the estimated machining load PL1 using the adjustment information a, i.e., to calculate the adjusted machining load PL2, and to accurately monitor subsequent machining using the adjusted machining load PL2.

[0046] Furthermore, in the machining system 10 according to one aspect of the present invention, the adjustment information specifying unit 54 of the machining system 10 is configured to be able to specify the adjustment information a after performing actual machining multiple times in order to suppress the influence of irregularities caused by casting defects in the workpiece W, clogging of cutting chips, breakage of the tool TL, etc. Therefore, it is possible to remove noise when an irregularity occurs and to specify the adjustment information a with high accuracy.

[0047] Furthermore, according to the machining system 10 according to one aspect of the present invention, since it is not necessary to specify the specific cutting resistance, the simulation unit 12 of the machining system 10 does not require high computing power or a special machining load measuring device. Therefore, the simulation unit 12 can be configured at low cost. Furthermore, the adjustment unit 14 is configured in an area separate from at least the machining load estimation unit 38 and the specific cutting resistance storage unit 46 within the simulation unit 12. This allows the machining system 10 to be configured while keeping the calculation models and know-how of the software vendor and the machine tool manufacturer confidential.

[0048] As described above, the machining system 10 according to this embodiment identifies adjustment information for comparing the estimated machining load with the actual machining load based on the actual machining load when actual machining is performed on the machine tool, and further adjusts the estimated machining load simply and accurately using the adjustment information, thereby enabling subsequent machining to be monitored accurately.

[0049] Here, the adjustment unit 14 has been described as being configured inside the simulation unit 12, but this is not limited to this, and it may be configured independently of the simulation unit, or may be configured inside the machine tool.

[0050] 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 vertically oriented spindle may be used instead of a vertical machine tool with a horizontally oriented spindle. Machine tools other than the machine tool 16 may also be included in the machining system 10. In addition to the above, it is believed that a person skilled in the art will understand that various modifications of the above embodiment are possible.

[0051] REFERENCE SIGNS LIST 10 Machining system 12 Simulation unit 14 Adjustment unit 16 Machine tool 18 Machine device 20 Control device 32 Detection unit 38 Machining load estimation unit 44 Motion step generation unit 46 Specific cutting resistance storage unit 48 Adjustment information storage unit 54 Adjustment information identification unit a Adjustment information PL1 Estimated machining load PL3 Actual machining load TL Tool W Workpiece

Claims

1. A machining system that executes a machining program on 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; 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 loads in the control device; and a monitoring unit that monitors the actual machining load; a simulation unit that has: a motion step generation unit that generates the motion steps; a machining load estimation unit that estimates the machining load of the machine for each motion step when the machining program is executed as an estimated machining load; and a specific cutting resistance storage unit that stores a specific cutting resistance used for the estimation in correspondence with workpiece information; an adjustment unit that has an adjustment information storage unit that stores adjustment information in correspondence with tool information and workpiece information, and adjusts the estimated machining load using the adjustment information; and an adjustment information identification unit that identifies adjustment information to be used to adjust the estimated estimated machining load based on a comparison between the estimated estimated machining load and the actual machining load, and stores the adjustment information in the adjustment information storage unit in correspondence with the tool information and workpiece information when the actual machining load occurs. a processing system including:

2. The machining system according to claim 1, wherein the machine tool performs the actual machining multiple times, and the adjustment information identification unit identifies the adjustment information based on multiple actual machining loads corresponding to the multiple actual machining times.

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